Commit FS#12069 - Playback rework - first stages. Gives as thorough as possible a treatment of codec management, track change and metadata logic as possible while maintaining fairly narrow focus and not rewriting everything all at once. Please see the rockbox-dev mail archive on 2011-04-25 (Playback engine rework) for a more thorough manifest of what was addressed. Plugins and codecs become incompatible.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29785 a1c6a512-1295-4272-9138-f99709370657

39 files changed, 1384 insertions, 1500 deletions

diff --git a/apps/codecs/a52.c b/apps/codecs/a52.c
index 00fdeea309..4cd293e37f 100644
--- a/apps/codecs/a52.c
+++ b/apps/codecs/a52.c
@@ -116,27 +116,31 @@ static void a52_decode_data(uint8_t *start, uint8_t *end)
 }
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 28);
+    }
+    else if (reason == CODEC_UNLOAD) {
+        if (state)
+            a52_free(state);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     size_t n;
     unsigned char *filebuf;
     int sample_loc;
-    int retval;
+    intptr_t param;
 
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 28);
-
-next_track:
-    retval = CODEC_OK;
-
-    if (codec_init()) {
-        retval = CODEC_ERROR;
-        goto exit;
-    }
-
-    if (codec_wait_taginfo() != 0)
-        goto request_next_track;
+    if (codec_init())
+        return CODEC_ERROR;
 
     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
     codec_set_replaygain(ci->id3);
@@ -153,15 +157,18 @@ next_track:
         }
     }
     else {
+        ci->seek_buffer(ci->id3->first_frame_offset);
         samplesdone = 0;
     }
 
     while (1) {
-        if (ci->stop_codec || ci->new_track)
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
 
-        if (ci->seek_time) {
-            sample_loc = (ci->seek_time - 1)/1000 * ci->id3->frequency;
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            sample_loc = param/1000 * ci->id3->frequency;
 
             if (ci->seek_buffer((sample_loc/A52_SAMPLESPERFRAME)*ci->id3->bytesperframe)) {
                 samplesdone = sample_loc;
@@ -179,11 +186,5 @@ next_track:
         ci->advance_buffer(n);
     }
 
-request_next_track:
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    a52_free(state);
-    return retval;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/a52_rm.c b/apps/codecs/a52_rm.c
index f5e4923292..c1930aa7b4 100644
--- a/apps/codecs/a52_rm.c
+++ b/apps/codecs/a52_rm.c
@@ -124,36 +124,44 @@ static void a52_decode_data(uint8_t *start, uint8_t *end)
     }
 }
 
-
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 28);
+    }
+    else if (reason == CODEC_UNLOAD) {
+        if (state)
+            a52_free(state);        
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     size_t n;
     uint8_t *filebuf;
-    int retval, consumed, packet_offset;
+    int consumed, packet_offset;
     int playback_on = -1;
     size_t resume_offset;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 28);
-
-next_track:
-    retval = CODEC_OK;
+    intptr_t param;
+    enum codec_command_action action = CODEC_ACTION_NULL;
 
     if (codec_init()) {
-        retval = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto request_next_track;
-
     resume_offset = ci->id3->offset;
 
     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
     codec_set_replaygain(ci->id3);
 
+    ci->seek_buffer(ci->id3->first_frame_offset);
+
     /* Intializations */
     state = a52_init(0);
     ci->memset(&rmctx,0,sizeof(RMContext)); 
@@ -165,26 +173,34 @@ next_track:
         resume_offset -= rmctx.data_offset + DATA_HEADER_SIZE;
         /* put number of subpackets to skip in resume_offset */
         resume_offset /= (rmctx.block_align + PACKET_HEADER_SIZE);
-        ci->seek_time =  (int)resume_offset * ((rmctx.block_align * 8 * 1000)/rmctx.bit_rate);                
+        param = (int)resume_offset * ((rmctx.block_align * 8 * 1000)/rmctx.bit_rate);
+        action = CODEC_ACTION_SEEK_TIME;
+    }
+    else {
+        /* Seek to the first packet */
+        ci->advance_buffer(rmctx.data_offset + DATA_HEADER_SIZE );
     }
-    
-    /* Seek to the first packet */
-    ci->advance_buffer(rmctx.data_offset + DATA_HEADER_SIZE );
 
     /* The main decoding loop */
     while((unsigned)rmctx.audio_pkt_cnt < rmctx.nb_packets) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track)
+        if (action == CODEC_ACTION_NULL)
+            action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
 
-        if (ci->seek_time) {
-            packet_offset = ci->seek_time / ((rmctx.block_align*8*1000)/rmctx.bit_rate);
-            ci->seek_buffer(rmctx.data_offset + DATA_HEADER_SIZE + packet_offset*(rmctx.block_align + PACKET_HEADER_SIZE));
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            packet_offset = param / ((rmctx.block_align*8*1000)/rmctx.bit_rate);
+            ci->seek_buffer(rmctx.data_offset + DATA_HEADER_SIZE +
+                            packet_offset*(rmctx.block_align + PACKET_HEADER_SIZE));
             rmctx.audio_pkt_cnt = packet_offset;
-            samplesdone = (rmctx.sample_rate/1000 * ci->seek_time);
+            samplesdone = (rmctx.sample_rate/1000 * param);
+            ci->set_elapsed(samplesdone/(frequency/1000));
             ci->seek_complete();
         }
 
+        action = CODEC_ACTION_NULL;
+
         filebuf = ci->request_buffer(&n, rmctx.block_align + PACKET_HEADER_SIZE);
         consumed = rm_get_packet(&filebuf, &rmctx, &pkt);
 
@@ -195,8 +211,7 @@ next_track:
                 return CODEC_ERROR;
             }
             else {
-                retval = CODEC_OK;
-                goto exit;
+                break;
             }
         }
 
@@ -205,11 +220,5 @@ next_track:
         ci->advance_buffer(pkt.length);
     }
 
-request_next_track:
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    a52_free(state);
-    return retval;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/aac.c b/apps/codecs/aac.c
index 5638dc49a9..90cf0438ce 100644
--- a/apps/codecs/aac.c
+++ b/apps/codecs/aac.c
@@ -33,7 +33,19 @@ CODEC_HEADER
 #define FAAD_BYTE_BUFFER_SIZE (2048-12)
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 29);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     /* Note that when dealing with QuickTime/MPEG4 files, terminology is
      * a bit confusing. Files with sound are split up in chunks, where
@@ -59,25 +71,15 @@ enum codec_status codec_main(void)
     uint32_t sbr_fac = 1;
     unsigned char c = 0;
     void *ret;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 29);
-
-next_track:
-    err = CODEC_OK;
+    intptr_t param;
 
     /* Clean and initialize decoder structures */
     memset(&demux_res , 0, sizeof(demux_res));
     if (codec_init()) {
         LOGF("FAAD: Codec init error\n");
-        err = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-  
     file_offset = ci->id3->offset;
 
     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
@@ -85,12 +87,13 @@ next_track:
 
     stream_create(&input_stream,ci);
 
+    ci->seek_buffer(ci->id3->first_frame_offset);
+
     /* if qtmovie_read returns successfully, the stream is up to
      * the movie data, which can be used directly by the decoder */
     if (!qtmovie_read(&input_stream, &demux_res)) {
         LOGF("FAAD: File init error\n");
-        err = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* initialise the sound converter */
@@ -98,8 +101,7 @@ next_track:
 
     if (!decoder) {
         LOGF("FAAD: Decode open error\n");
-        err = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     NeAACDecConfigurationPtr conf = NeAACDecGetCurrentConfiguration(decoder);
@@ -109,8 +111,7 @@ next_track:
     err = NeAACDecInit2(decoder, demux_res.codecdata, demux_res.codecdata_len, &s, &c);
     if (err) {
         LOGF("FAAD: DecInit: %d, %d\n", err, decoder->object_type);
-        err = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
 #ifdef SBR_DEC
@@ -150,20 +151,19 @@ next_track:
 
     /* The main decoding loop */
     while (i < demux_res.num_sample_byte_sizes) {
-        ci->yield();
+        enum codec_command_action action = ci->get_command(&param);
 
-        if (ci->stop_codec || ci->new_track) {
+        if (action == CODEC_ACTION_HALT)
             break;
-        }
 
         /* Deal with any pending seek requests */
-        if (ci->seek_time) {
+        if (action == CODEC_ACTION_SEEK_TIME) {
             /* Seek to the desired time position. Important: When seeking in SBR
              * upsampling files the seek_time must be divided by 2 when calling 
              * m4a_seek and the resulting sound_samples_done must be expanded 
              * by a factor 2. This is done via using sbr_fac. */
             if (m4a_seek(&demux_res, &input_stream,
-                          ((ci->seek_time-1)/10/sbr_fac)*(ci->id3->frequency/100),
+                          (param/10/sbr_fac)*(ci->id3->frequency/100),
                           &sound_samples_done, (int*) &i)) {
                 sound_samples_done *= sbr_fac;
                 elapsed_time = (sound_samples_done * 10) / (ci->id3->frequency / 100);
@@ -194,8 +194,7 @@ next_track:
         else if (file_offset == 0)
         {
             LOGF("AAC: get_sample_offset error\n");
-            err = CODEC_ERROR;
-            goto done;
+            return CODEC_ERROR;
         }
         
         /* Request the required number of bytes from the input buffer */
@@ -207,8 +206,7 @@ next_track:
         /* NeAACDecDecode may sometimes return NULL without setting error. */
         if (ret == NULL || frame_info.error > 0) {
             LOGF("FAAD: decode error '%s'\n", NeAACDecGetErrorMessage(frame_info.error));
-            err = CODEC_ERROR;
-            goto done;
+            return CODEC_ERROR;
         }
 
         /* Advance codec buffer (no need to call set_offset because of this) */
@@ -251,12 +249,6 @@ next_track:
         i++;
     }
 
-done:
     LOGF("AAC: Decoded %lu samples\n", (unsigned long)sound_samples_done);
-
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    return err;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/adx.c b/apps/codecs/adx.c
index 832b94797b..a1b57fce58 100644
--- a/apps/codecs/adx.c
+++ b/apps/codecs/adx.c
@@ -45,7 +45,19 @@ static const long cutoff = 500;
 static int16_t samples[WAV_CHUNK_SIZE] IBSS_ATTR;
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        /* we only render 16 bits */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 16);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     int channels;
     int sampleswritten, i;
@@ -62,12 +74,8 @@ enum codec_status codec_main(void)
     off_t chanstart, bufoff;
     /*long coef1=0x7298L,coef2=-0x3350L;*/
     long coef1, coef2;
+    intptr_t param;
 
-    /* Generic codec initialisation */
-    /* we only render 16 bits */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 16);
-  
-next_track:
     DEBUGF("ADX: next_track\n");
     if (codec_init()) {
         return CODEC_ERROR;
@@ -77,10 +85,6 @@ next_track:
     /* init history */
     ch1_1=ch1_2=ch2_1=ch2_2=0;
 
-    /* wait for track info to load */
-    if (codec_wait_taginfo() != 0)
-        goto request_next_track;
-
     codec_set_replaygain(ci->id3);
         
     /* Get header */
@@ -226,10 +230,10 @@ next_track:
     /* The main decoder loop */
         
     while (!endofstream) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
-        }
         
         /* do we need to loop? */
         if (bufoff > end_adr-18*channels && looping) {
@@ -254,17 +258,17 @@ next_track:
         }
 
         /* do we need to seek? */
-        if (ci->seek_time) {
+        if (action == CODEC_ACTION_SEEK_TIME) {
             uint32_t newpos;
             
-            DEBUGF("ADX: seek to %ldms\n",ci->seek_time);
+            DEBUGF("ADX: seek to %ldms\n", (long)param);
 
             endofstream = 0;
             loop_count = 0;
             fade_count = -1; /* disable fade */
             fade_frames = 1;
 
-            newpos = (((uint64_t)avgbytespersec*(ci->seek_time - 1))
+            newpos = (((uint64_t)avgbytespersec*param)
                       / (1000LL*18*channels))*(18*channels);
             bufoff = chanstart + newpos;
             while (bufoff > end_adr-18*channels) {
@@ -385,9 +389,5 @@ next_track:
            1000LL/avgbytespersec);
     }
 
-request_next_track:
-    if (ci->request_next_track())
-        goto next_track;
-
     return CODEC_OK;
 }
diff --git a/apps/codecs/aiff.c b/apps/codecs/aiff.c
index d4cf8660dd..3fc137eaeb 100644
--- a/apps/codecs/aiff.c
+++ b/apps/codecs/aiff.c
@@ -61,9 +61,20 @@ static const struct pcm_codec *get_codec(uint32_t formattag)
     return NULL;
 }
 
-enum codec_status codec_main(void)
+/* this is the codec entry point */
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, PCM_OUTPUT_DEPTH-1);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
-    int status;
     struct pcm_format format;
     uint32_t bytesdone, decodedsamples;
     uint32_t num_sample_frames = 0;
@@ -77,38 +88,28 @@ enum codec_status codec_main(void)
     bool is_aifc = false;
     const struct pcm_codec *codec;
     uint32_t size;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, PCM_OUTPUT_DEPTH-1);
-  
-next_track:
-    status = CODEC_OK;
+    intptr_t param;
 
     if (codec_init()) {
-        status = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     codec_set_replaygain(ci->id3);
     
     /* Need to save offset for later use (cleared indirectly by advance_buffer) */
     bytesdone = ci->id3->offset;
 
     /* assume the AIFF header is less than 1024 bytes */
+    ci->seek_buffer(0);
     buf = ci->request_buffer(&n, 1024);
     if (n < 54) {
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     if (memcmp(buf, "FORM", 4) != 0)
     {
         DEBUGF("CODEC_ERROR: does not aiff format %4.4s\n", (char*)&buf[0]);
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
     if (memcmp(&buf[8], "AIFF", 4) == 0)
         is_aifc = false;
@@ -117,8 +118,7 @@ next_track:
     else
     {
         DEBUGF("CODEC_ERROR: does not aiff format %4.4s\n", (char*)&buf[8]);
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     buf += 12;
@@ -141,8 +141,7 @@ next_track:
             {
                 DEBUGF("CODEC_ERROR: 'COMM' chunk size=%lu < %d\n",
                        (unsigned long)size, (is_aifc)?22:18);
-                status = CODEC_ERROR;
-                goto done;
+                return CODEC_ERROR;
             }
             /* num_channels */
             format.channels = ((buf[8]<<8)|buf[9]);
@@ -154,8 +153,7 @@ next_track:
             /* sample_rate (don't use last 4 bytes, only integer fs) */
             if (buf[16] != 0x40) {
                 DEBUGF("CODEC_ERROR: weird sampling rate (no @)\n");
-                status = CODEC_ERROR;
-                goto done;
+                return CODEC_ERROR;
             }
             format.samplespersec = ((buf[18]<<24)|(buf[19]<<16)|(buf[20]<<8)|buf[21])+1;
             format.samplespersec >>= (16 + 14 - buf[17]);
@@ -181,8 +179,7 @@ next_track:
         } else if (memcmp(buf, "SSND", 4)==0) {
             if (format.bitspersample == 0) {
                 DEBUGF("CODEC_ERROR: unsupported chunk order\n");
-                status = CODEC_ERROR;
-                goto done;
+                return CODEC_ERROR;
             }
             /* offset2snd */
             offset2snd = (buf[8]<<24)|(buf[9]<<16)|(buf[10]<<8)|buf[11];
@@ -205,21 +202,18 @@ next_track:
         buf += size;
         if (n < size) {
             DEBUGF("CODEC_ERROR: AIFF header size > 1024\n");
-            status = CODEC_ERROR;
-            goto done;
+            return CODEC_ERROR;
         }
         n -= size;
     } /* while 'SSND' */
 
     if (format.channels == 0) {
         DEBUGF("CODEC_ERROR: 'COMM' chunk not found or 0-channels file\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
     if (format.numbytes == 0) {
         DEBUGF("CODEC_ERROR: 'SSND' chunk not found or has zero length\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     codec = get_codec(format.formattag);
@@ -227,14 +221,12 @@ next_track:
     {
         DEBUGF("CODEC_ERROR: AIFC does not support compressionType: 0x%x\n", 
             (unsigned int)format.formattag);
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     if (!codec->set_format(&format))
     {
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
@@ -245,21 +237,18 @@ next_track:
         ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
     } else {
         DEBUGF("CODEC_ERROR: more than 2 channels unsupported\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     if (format.samplesperblock == 0)
     {
         DEBUGF("CODEC_ERROR: samplesperblock is 0\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
     if (format.blockalign == 0)
     {
         DEBUGF("CODEC_ERROR: blockalign is 0\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* check chunksize */
@@ -269,8 +258,7 @@ next_track:
     if (format.chunksize == 0)
     {
         DEBUGF("CODEC_ERROR: chunksize is 0\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     firstblockposn = 1024 - n;
@@ -283,13 +271,13 @@ next_track:
                                                      PCM_SEEK_POS, NULL);
 
         if (newpos->pos > format.numbytes)
-            goto done;
+            return CODEC_OK;
+
         if (ci->seek_buffer(firstblockposn + newpos->pos))
         {
             bytesdone      = newpos->pos;
             decodedsamples = newpos->samples;
         }
-        ci->seek_complete();
     } else {
         /* already where we need to be */
         bytesdone = 0;
@@ -299,21 +287,29 @@ next_track:
     endofstream = 0;
 
     while (!endofstream) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track)
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
 
-        if (ci->seek_time) {
+        if (action == CODEC_ACTION_SEEK_TIME) {
             /* 3rd args(read_buffer) is unnecessary in the format which AIFF supports. */
-            struct pcm_pos *newpos = codec->get_seek_pos(ci->seek_time, PCM_SEEK_TIME, NULL);
+            struct pcm_pos *newpos = codec->get_seek_pos(param, PCM_SEEK_TIME, NULL);
 
             if (newpos->pos > format.numbytes)
+            {
+                ci->set_elapsed(ci->id3->length);
+                ci->seek_complete();
                 break;
+            }
+
             if (ci->seek_buffer(firstblockposn + newpos->pos))
             {
                 bytesdone      = newpos->pos;
                 decodedsamples = newpos->samples;
             }
+
+            ci->set_elapsed(decodedsamples*1000LL/ci->id3->frequency);
             ci->seek_complete();
         }
         aifbuf = (uint8_t *)ci->request_buffer(&n, format.chunksize);
@@ -326,11 +322,10 @@ next_track:
             endofstream = 1;
         }
 
-        status = codec->decode(aifbuf, n, samples, &bufcount);
-        if (status == CODEC_ERROR)
+        if (codec->decode(aifbuf, n, samples, &bufcount) == CODEC_ERROR)
         {
             DEBUGF("codec error\n");
-            goto done;
+            return CODEC_ERROR;
         }
 
         ci->pcmbuf_insert(samples, NULL, bufcount);
@@ -343,13 +338,6 @@ next_track:
 
         ci->set_elapsed(decodedsamples*1000LL/ci->id3->frequency);
     }
-    status = CODEC_OK;
-
-done:
-    if (ci->request_next_track())
-        goto next_track;
 
-exit:
-    return status;
+    return CODEC_OK;
 }
-
diff --git a/apps/codecs/aiff_enc.c b/apps/codecs/aiff_enc.c
index 69496f70ac..fc44196eb0 100644
--- a/apps/codecs/aiff_enc.c
+++ b/apps/codecs/aiff_enc.c
@@ -359,40 +359,42 @@ static bool init_encoder(void)
     return true;
 } /* init_encoder */
 
-/* main codec entry point */
-enum codec_status codec_main(void)
+/* this is the codec entry point */
+enum codec_status codec_main(enum codec_entry_call_reason reason)
 {
-    if (!init_encoder())
-        return CODEC_ERROR;
+    if (reason == CODEC_LOAD) {
+        if (!init_encoder())
+            return CODEC_ERROR;
+    }
+    else if (reason == CODEC_UNLOAD) {
+        /* reset parameters to initial state */
+        ci->enc_set_parameters(NULL);
+    }
 
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
+{
     /* main encoding loop */
-    while(!ci->stop_codec)
+    while (ci->get_command(NULL) != CODEC_ACTION_HALT)
     {
-        uint32_t *src;
+        uint32_t *src = (uint32_t *)ci->enc_get_pcm_data(PCM_CHUNK_SIZE);
+        struct enc_chunk_hdr *chunk;
 
-        while ((src = (uint32_t *)ci->enc_get_pcm_data(PCM_CHUNK_SIZE)) != NULL)
-        {
-            struct enc_chunk_hdr *chunk;
-
-            if (ci->stop_codec)
-                break;
+        if (src == NULL)
+            continue;
 
-            chunk           = ci->enc_get_chunk();
-            chunk->enc_size = enc_size;
-            chunk->num_pcm  = PCM_SAMP_PER_CHUNK;
-            chunk->enc_data = ENC_CHUNK_SKIP_HDR(chunk->enc_data, chunk);
+        chunk           = ci->enc_get_chunk();
+        chunk->enc_size = enc_size;
+        chunk->num_pcm  = PCM_SAMP_PER_CHUNK;
+        chunk->enc_data = ENC_CHUNK_SKIP_HDR(chunk->enc_data, chunk);
 
-            chunk_to_aiff_format(src, (uint32_t *)chunk->enc_data);
-
-            ci->enc_finish_chunk();
-            ci->yield();
-        }
+        chunk_to_aiff_format(src, (uint32_t *)chunk->enc_data);
 
-        ci->yield();
+        ci->enc_finish_chunk();
     }
 
-    /* reset parameters to initial state */
-    ci->enc_set_parameters(NULL);
- 
     return CODEC_OK;
-} /* codec_start */
+}
diff --git a/apps/codecs/alac.c b/apps/codecs/alac.c
index cd9129a278..82bda264c3 100644
--- a/apps/codecs/alac.c
+++ b/apps/codecs/alac.c
@@ -32,116 +32,114 @@ CODEC_HEADER
 static int32_t outputbuffer[ALAC_MAX_CHANNELS][ALAC_BLOCKSIZE] IBSS_ATTR;
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
 {
-  size_t n;
-  demux_res_t demux_res;
-  stream_t input_stream;
-  uint32_t samplesdone;
-  uint32_t elapsedtime;
-  int samplesdecoded;
-  unsigned int i;
-  unsigned char* buffer;
-  alac_file alac;
-  int retval;
-
-  /* Generic codec initialisation */
-  ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
-  ci->configure(DSP_SET_SAMPLE_DEPTH, ALAC_OUTPUT_DEPTH-1);
-
-  next_track:
-    retval = CODEC_OK;
-
-  /* Clean and initialize decoder structures */
-   memset(&demux_res , 0, sizeof(demux_res));
-  if (codec_init()) {
-    LOGF("ALAC: Error initialising codec\n");
-    retval = CODEC_ERROR;
-    goto exit;
-  }
-
-  if (codec_wait_taginfo() != 0)
-    goto done;
-  
-  ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
-  codec_set_replaygain(ci->id3);
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
+        ci->configure(DSP_SET_SAMPLE_DEPTH, ALAC_OUTPUT_DEPTH-1);
+    }
 
-  stream_create(&input_stream,ci);
+    return CODEC_OK;
+}
 
-  /* Read from ci->id3->offset before calling qtmovie_read. */
-  samplesdone = (uint32_t)(((uint64_t)(ci->id3->offset) * ci->id3->frequency) /  
-                (ci->id3->bitrate*128));
-  
-  /* if qtmovie_read returns successfully, the stream is up to
-   * the movie data, which can be used directly by the decoder */
-  if (!qtmovie_read(&input_stream, &demux_res)) {
-    LOGF("ALAC: Error initialising file\n");
-    retval = CODEC_ERROR;
-    goto done;
-  }
-
-  /* initialise the sound converter */
-  create_alac(demux_res.sound_sample_size, demux_res.num_channels,&alac);
-  alac_set_info(&alac, demux_res.codecdata);
-  
-  /* Set i for first frame, seek to desired sample position for resuming. */
-  i=0;
-  if (samplesdone > 0) {
-    if (m4a_seek(&demux_res, &input_stream, samplesdone,
-                  &samplesdone, (int*) &i)) {
-        elapsedtime = (samplesdone * 10) / (ci->id3->frequency / 100);
-        ci->set_elapsed(elapsedtime);
-    } else {
-        samplesdone = 0;
+/* this is called for each file to process */
+enum codec_status codec_run(void)
+{
+    size_t n;
+    demux_res_t demux_res;
+    stream_t input_stream;
+    uint32_t samplesdone;
+    uint32_t elapsedtime = 0;
+    int samplesdecoded;
+    unsigned int i;
+    unsigned char* buffer;
+    alac_file alac;
+    intptr_t param;
+
+    /* Clean and initialize decoder structures */
+    memset(&demux_res , 0, sizeof(demux_res));
+    if (codec_init()) {
+        LOGF("ALAC: Error initialising codec\n");
+        return CODEC_ERROR;
     }
-  }
 
-  /* The main decoding loop */
-  while (i < demux_res.num_sample_byte_sizes) {
-    ci->yield();
-    if (ci->stop_codec || ci->new_track) {
-      break;
+    ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
+    codec_set_replaygain(ci->id3);
+
+    ci->seek_buffer(0);
+
+    stream_create(&input_stream,ci);
+
+    /* Read from ci->id3->offset before calling qtmovie_read. */
+    samplesdone = (uint32_t)(((uint64_t)(ci->id3->offset) * ci->id3->frequency) /  
+                  (ci->id3->bitrate*128));
+  
+    /* if qtmovie_read returns successfully, the stream is up to
+     * the movie data, which can be used directly by the decoder */
+    if (!qtmovie_read(&input_stream, &demux_res)) {
+        LOGF("ALAC: Error initialising file\n");
+        return CODEC_ERROR;
     }
 
-    /* Deal with any pending seek requests */
-    if (ci->seek_time) {
-      if (m4a_seek(&demux_res, &input_stream,
-                    ((ci->seek_time-1)/10) * (ci->id3->frequency/100),
-                    &samplesdone, (int *)&i)) {
-        elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
-        ci->set_elapsed(elapsedtime);
-      }
-      ci->seek_complete();
+    /* initialise the sound converter */
+    create_alac(demux_res.sound_sample_size, demux_res.num_channels,&alac);
+    alac_set_info(&alac, demux_res.codecdata);
+  
+    /* Set i for first frame, seek to desired sample position for resuming. */
+    i=0;
+    if (samplesdone > 0) {
+        if (m4a_seek(&demux_res, &input_stream, samplesdone,
+                      &samplesdone, (int*) &i)) {
+            elapsedtime = (samplesdone * 10) / (ci->id3->frequency / 100);
+            ci->set_elapsed(elapsedtime);
+        } else {
+            samplesdone = 0;
+        }
     }
 
-    /* Request the required number of bytes from the input buffer */
-    buffer=ci->request_buffer(&n, ALAC_BYTE_BUFFER_SIZE);
+    /* The main decoding loop */
+    while (i < demux_res.num_sample_byte_sizes) {
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
+            break;
 
-    /* Decode one block - returned samples will be host-endian */
-    ci->yield();
-    samplesdecoded=alac_decode_frame(&alac, buffer, outputbuffer, ci->yield);
+        /* Request the required number of bytes from the input buffer */
+        buffer=ci->request_buffer(&n, ALAC_BYTE_BUFFER_SIZE);
 
-    /* Advance codec buffer by amount of consumed bytes */
-    ci->advance_buffer(alac.bytes_consumed);
+        /* Deal with any pending seek requests */
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            if (m4a_seek(&demux_res, &input_stream,
+                         (param/10) * (ci->id3->frequency/100),
+                         &samplesdone, (int *)&i)) {
+                elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
+            }
+            ci->set_elapsed(elapsedtime);
+            ci->seek_complete();
+        }
 
-    /* Output the audio */
-    ci->yield();
-    ci->pcmbuf_insert(outputbuffer[0], outputbuffer[1], samplesdecoded);
+        /* Request the required number of bytes from the input buffer */
+        buffer=ci->request_buffer(&n, ALAC_BYTE_BUFFER_SIZE);
 
-    /* Update the elapsed-time indicator */
-    samplesdone+=samplesdecoded;
-    elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
-    ci->set_elapsed(elapsedtime);
+        /* Decode one block - returned samples will be host-endian */
+        samplesdecoded=alac_decode_frame(&alac, buffer, outputbuffer, ci->yield);
+        ci->yield();
 
-    i++;
-  }
+        /* Advance codec buffer by amount of consumed bytes */
+        ci->advance_buffer(alac.bytes_consumed);
 
-done:
-  LOGF("ALAC: Decoded %lu samples\n",(unsigned long)samplesdone);
+        /* Output the audio */
+        ci->pcmbuf_insert(outputbuffer[0], outputbuffer[1], samplesdecoded);
 
-  if (ci->request_next_track())
-   goto next_track;
+        /* Update the elapsed-time indicator */
+        samplesdone+=samplesdecoded;
+        elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
+        ci->set_elapsed(elapsedtime);
+
+        i++;
+    }
 
-exit:
-  return retval;
+    LOGF("ALAC: Decoded %lu samples\n",(unsigned long)samplesdone);
+    return CODEC_OK;
 }
diff --git a/apps/codecs/ape.c b/apps/codecs/ape.c
index 11d973ab26..8f95a01ec7 100644
--- a/apps/codecs/ape.c
+++ b/apps/codecs/ape.c
@@ -127,13 +127,23 @@ static void ape_resume(struct ape_ctx_t* ape_ctx, size_t resume_offset,
 }
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, APE_OUTPUT_DEPTH-1);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     struct ape_ctx_t ape_ctx;
     uint32_t samplesdone;
     uint32_t elapsedtime;
     size_t bytesleft;
-    int retval;
 
     uint32_t currentframe;
     uint32_t newfilepos;
@@ -145,33 +155,24 @@ enum codec_status codec_main(void)
     int res;
     int firstbyte;
     size_t resume_offset;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, APE_OUTPUT_DEPTH-1);
-
-next_track:
-    retval = CODEC_OK;
+    intptr_t param;
 
     if (codec_init()) {
         LOGF("APE: Error initialising codec\n");
-        retval = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     /* Remember the resume position - when the codec is opened, the
        playback engine will reset it. */
     resume_offset = ci->id3->offset;
 
+    ci->seek_buffer(0);
     inbuffer = ci->request_buffer(&bytesleft, INPUT_CHUNKSIZE);
 
     /* Read the file headers to populate the ape_ctx struct */
     if (ape_parseheaderbuf(inbuffer,&ape_ctx) < 0) {
         LOGF("APE: Error reading header\n");
-        retval = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
     /* Initialise the seektable for this file */
@@ -243,16 +244,16 @@ frame_start:
         /* Decode the frame a chunk at a time */
         while (nblocks > 0)
         {
-            ci->yield();
-            if (ci->stop_codec || ci->new_track) {
+            enum codec_command_action action = ci->get_command(&param);
+
+            if (action == CODEC_ACTION_HALT)
                 goto done;
-            }
 
             /* Deal with any pending seek requests */
-            if (ci->seek_time) 
+            if (action == CODEC_ACTION_SEEK_TIME) 
             {
                 if (ape_calc_seekpos(&ape_ctx,
-                    ((ci->seek_time-1)/10) * (ci->id3->frequency/100),
+                    (param/10) * (ci->id3->frequency/100),
                     &currentframe,
                     &newfilepos,
                     &samplestoskip))
@@ -266,9 +267,12 @@ frame_start:
                     ci->seek_buffer(newfilepos);
                     inbuffer = ci->request_buffer(&bytesleft, INPUT_CHUNKSIZE);
 
+                    elapsedtime = (samplesdone*10)/(ape_ctx.samplerate/100);
+                    ci->set_elapsed(elapsedtime);
                     ci->seek_complete();
                     goto frame_start;  /* Sorry... */
                 }
+
                 ci->seek_complete();
             }
 
@@ -281,8 +285,7 @@ frame_start:
             {
                 /* Frame decoding error, abort */
                 LOGF("APE: Frame %lu, error %d\n",(unsigned long)currentframe,res);
-                retval = CODEC_ERROR;
-                goto done;
+                return CODEC_ERROR;
             }
 
             ci->yield();
@@ -320,10 +323,5 @@ frame_start:
 
 done:
     LOGF("APE: Decoded %lu samples\n",(unsigned long)samplesdone);
-
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    return retval;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/asap.c b/apps/codecs/asap.c
index 9447c738d2..f12dc6a0c5 100644
--- a/apps/codecs/asap.c
+++ b/apps/codecs/asap.c
@@ -29,24 +29,21 @@ CODEC_HEADER
 static byte samples[CHUNK_SIZE] IBSS_ATTR;   /* The sample buffer */
 static ASAP_State asap;         /* asap codec state */
 
-/* this is the codec entry point */
-enum codec_status codec_main(void)
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     int n_bytes;
     int song;
     int duration;
     char* module;
     int bytesPerSample =2;
+    intptr_t param;
     
-next_track:
     if (codec_init()) {
         DEBUGF("codec init failed\n");
         return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto request_next_track;
-
     codec_set_replaygain(ci->id3);
         
     int bytes_done =0;   
@@ -97,19 +94,20 @@ next_track:
     
     /* The main decoder loop */    
     while (1) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track)
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
 
-        if (ci->seek_time) {
-            /* New time is ready in ci->seek_time */
-                      
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            /* New time is ready in param */
+
             /* seek to pos */
-            ASAP_Seek(&asap,ci->seek_time);
-            /* update elapsed */
-            ci->set_elapsed(ci->seek_time);
+            ASAP_Seek(&asap,param);
             /* update bytes_done */
-            bytes_done = ci->seek_time*44.1*2;    
+            bytes_done = param*44.1*2;    
+            /* update elapsed */
+            ci->set_elapsed((bytes_done / 2) / 44.1);
             /* seek ready */    
             ci->seek_complete();            
         }
@@ -129,10 +127,6 @@ next_track:
         if(n_bytes != sizeof(samples))
             break;
     }
-
-request_next_track:
-    if (ci->request_next_track())
-        goto next_track;
  
     return CODEC_OK;    
 }
diff --git a/apps/codecs/atrac3_oma.c b/apps/codecs/atrac3_oma.c
index 73f3ad29fd..ab24783368 100644
--- a/apps/codecs/atrac3_oma.c
+++ b/apps/codecs/atrac3_oma.c
@@ -33,24 +33,22 @@ CODEC_HEADER
 
 static ATRAC3Context q IBSS_ATTR;
 
-/* this is the codec entry point */
-enum codec_status codec_main(void)
-{ 
+/* this is called for each file to process */
+enum codec_status codec_run(void)
+{
     static size_t buff_size;
     int datasize, res, frame_counter, total_frames, seek_frame_offset;
     uint8_t *bit_buffer;
     int elapsed = 0;
     size_t resume_offset;
+    intptr_t param;
+    enum codec_command_action action = CODEC_ACTION_NULL;
 
-next_track:
     if (codec_init()) {
         DEBUGF("codec init failed\n");
         return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     resume_offset = ci->id3->offset;
 
     codec_set_replaygain(ci->id3);
@@ -60,84 +58,88 @@ next_track:
     ci->configure(DSP_SET_SAMPLE_DEPTH, 17); /* Remark: atrac3 uses s15.0 by default, s15.2 was hacked. */
     ci->configure(DSP_SET_STEREO_MODE, ci->id3->channels == 1 ?
         STEREO_MONO : STEREO_NONINTERLEAVED);
-    
-    res =atrac3_decode_init(&q, ci->id3);
+
+    ci->seek_buffer(0);
+
+    res = atrac3_decode_init(&q, ci->id3);
     if(res < 0) {
         DEBUGF("failed to initialize OMA atrac decoder\n");
         return CODEC_ERROR;
     }
 
+    total_frames = (ci->id3->filesize - ci->id3->first_frame_offset) / FRAMESIZE;
+    frame_counter = 0;
+    
     /* check for a mid-track resume and force a seek time accordingly */
     if(resume_offset > ci->id3->first_frame_offset) {
         resume_offset -= ci->id3->first_frame_offset;
         /* calculate resume_offset in frames */
         resume_offset = (int)resume_offset / FRAMESIZE;
-        ci->seek_time =  (int)resume_offset * ((FRAMESIZE * 8)/BITRATE);                
+        param = (int)resume_offset * ((FRAMESIZE * 8)/BITRATE);
+        action = CODEC_ACTION_SEEK_TIME;
+    }
+    else {
+        ci->set_elapsed(0);
+        ci->seek_buffer(ci->id3->first_frame_offset);
     }
-    total_frames = (ci->id3->filesize - ci->id3->first_frame_offset) / FRAMESIZE;
-    frame_counter = 0;
-    
-    ci->set_elapsed(0);
-    ci->seek_buffer(0);
-    ci->advance_buffer(ci->id3->first_frame_offset);
 
     /* The main decoder loop */  
-seek_start :         
     while(frame_counter < total_frames)
-    {  
+    {
+        if (action == CODEC_ACTION_NULL)
+            action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
+            break;
+
         bit_buffer = (uint8_t *) ci->request_buffer(&buff_size, FRAMESIZE);
 
-        ci->yield();
-        if (ci->stop_codec || ci->new_track)
-            goto done;
-
-            if (ci->seek_time) {
-                ci->set_elapsed(ci->seek_time);
-
-                /* Do not allow seeking beyond the file's length */
-                if ((unsigned) ci->seek_time > ci->id3->length) {
-                    ci->seek_complete();
-                    goto done;
-                }       
-
-                /* Seek to the start of the track */
-                if (ci->seek_time == 1) {
-                    ci->set_elapsed(0);
-                    ci->seek_complete();
-                    ci->seek_buffer(ci->id3->first_frame_offset);
-                    elapsed = 0;
-                    goto seek_start;           
-                }                                                                
-                seek_frame_offset = (ci->seek_time * BITRATE) / (8 * FRAMESIZE);
-                frame_counter = seek_frame_offset;
-                ci->seek_buffer(ci->id3->first_frame_offset + seek_frame_offset* FRAMESIZE);
-                bit_buffer = (uint8_t *) ci->request_buffer(&buff_size, FRAMESIZE);
-                elapsed = ci->seek_time;
-
-                ci->set_elapsed(elapsed);
-                ci->seek_complete(); 
-            }
-
-            res = atrac3_decode_frame(FRAMESIZE, &q, &datasize, bit_buffer, FRAMESIZE);
-
-            if(res != (int)FRAMESIZE) {
-                DEBUGF("codec error\n");
-                return CODEC_ERROR;
-            }
-
-            if(datasize)
-                ci->pcmbuf_insert(q.outSamples, q.outSamples + 1024, q.samples_per_frame / ci->id3->channels);
-
-            elapsed += (FRAMESIZE * 8) / BITRATE;
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            /* Do not allow seeking beyond the file's length */
+            if ((unsigned) param > ci->id3->length) {
+                ci->set_elapsed(ci->id3->length);
+                ci->seek_complete();
+                break;
+            }       
+
+            /* Seek to the start of the track */
+            if (param == 0) {
+                elapsed = 0;
+                ci->set_elapsed(0);
+                ci->seek_buffer(ci->id3->first_frame_offset);
+                ci->seek_complete();
+                action = CODEC_ACTION_NULL;
+                continue;           
+            }                                                                
+
+            seek_frame_offset = (param * BITRATE) / (8 * FRAMESIZE);
+            frame_counter = seek_frame_offset;
+            ci->seek_buffer(ci->id3->first_frame_offset + seek_frame_offset* FRAMESIZE);
+            bit_buffer = (uint8_t *) ci->request_buffer(&buff_size, FRAMESIZE);
+            elapsed = param;
             ci->set_elapsed(elapsed);
-        
-            ci->advance_buffer(FRAMESIZE);
-            frame_counter++;
-    }
+            ci->seek_complete(); 
+        }
+
+        action = CODEC_ACTION_NULL;
 
-    done:
-    if (ci->request_next_track())
-        goto next_track;
+        res = atrac3_decode_frame(FRAMESIZE, &q, &datasize, bit_buffer, FRAMESIZE);
+
+        if(res != (int)FRAMESIZE) {
+            DEBUGF("codec error\n");
+            return CODEC_ERROR;
+        }
+
+        if(datasize)
+            ci->pcmbuf_insert(q.outSamples, q.outSamples + 1024,
+                              q.samples_per_frame / ci->id3->channels);
+
+        elapsed += (FRAMESIZE * 8) / BITRATE;
+        ci->set_elapsed(elapsed);
+
+        ci->advance_buffer(FRAMESIZE);
+        frame_counter++;
+    }
 
     return CODEC_OK;    
 }
diff --git a/apps/codecs/atrac3_rm.c b/apps/codecs/atrac3_rm.c
index 6a77d24283..1322e917ed 100644
--- a/apps/codecs/atrac3_rm.c
+++ b/apps/codecs/atrac3_rm.c
@@ -41,9 +41,9 @@ static void init_rm(RMContext *rmctx)
     memcpy(ci->id3->id3v2buf, (char*)rmctx->codec_extradata, rmctx->extradata_size*sizeof(char));
 }
 
-/* this is the codec entry point */
-enum codec_status codec_main(void)
-{ 
+/* this is called for each file to process */
+enum codec_status codec_run(void)
+{
     static size_t buff_size;
     int datasize, res, consumed, i, time_offset;
     uint8_t *bit_buffer;
@@ -52,16 +52,14 @@ enum codec_status codec_main(void)
     int scrambling_unit_size, num_units, elapsed = 0;
     int playback_on = -1;
     size_t resume_offset;
+    intptr_t param;
+    enum codec_command_action action = CODEC_ACTION_NULL;
 
-next_track:
     if (codec_init()) {
         DEBUGF("codec init failed\n");
         return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     resume_offset = ci->id3->offset;
 
     codec_set_replaygain(ci->id3);
@@ -69,6 +67,7 @@ next_track:
     ci->memset(&pkt,0,sizeof(RMPacket));
     ci->memset(&q,0,sizeof(ATRAC3Context));
 
+    ci->seek_buffer(0);
     init_rm(&rmctx);
  
     ci->configure(DSP_SET_FREQUENCY, ci->id3->frequency);
@@ -84,22 +83,25 @@ next_track:
     h = rmctx.sub_packet_h;
     scrambling_unit_size = h*fs;
     
-    res =atrac3_decode_init(&q, ci->id3);
+    res = atrac3_decode_init(&q, ci->id3);
     if(res < 0) {
         DEBUGF("failed to initialize RM atrac decoder\n");
         return CODEC_ERROR;
     }
-
+    
     /* check for a mid-track resume and force a seek time accordingly */
     if(resume_offset > rmctx.data_offset + DATA_HEADER_SIZE) {
         resume_offset -= rmctx.data_offset + DATA_HEADER_SIZE;
         num_units = (int)resume_offset / scrambling_unit_size;        
         /* put number of subpackets to skip in resume_offset */
         resume_offset /= (sps + PACKET_HEADER_SIZE);
-        ci->seek_time =  (int)resume_offset * ((sps * 8 * 1000)/rmctx.bit_rate);                
+        param = (int)resume_offset * ((sps * 8 * 1000)/rmctx.bit_rate);
+        action = CODEC_ACTION_SEEK_TIME;
     }
-    
-    ci->set_elapsed(0);
+    else {
+        ci->set_elapsed(0);
+    }
+
     ci->advance_buffer(rmctx.data_offset + DATA_HEADER_SIZE);
 
     /* The main decoder loop */  
@@ -115,22 +117,23 @@ seek_start :
                 return CODEC_ERROR;
             }
             else
-                goto done;
+                return CODEC_OK;
         }
 
         for(i = 0; i < rmctx.audio_pkt_cnt*(fs/sps) ; i++)
         { 
-            ci->yield();
-            if (ci->stop_codec || ci->new_track)
-                goto done;
+            if (action == CODEC_ACTION_NULL)
+                action = ci->get_command(&param);
 
-            if (ci->seek_time) {
-                ci->set_elapsed(ci->seek_time);
+            if (action == CODEC_ACTION_HALT)
+                return CODEC_OK;
 
+            if (action == CODEC_ACTION_SEEK_TIME) {
                 /* Do not allow seeking beyond the file's length */
-                if ((unsigned) ci->seek_time > ci->id3->length) {
+                if ((unsigned) param > ci->id3->length) {
+                    ci->set_elapsed(ci->id3->length);
                     ci->seek_complete();
-                    goto done;
+                    return CODEC_OK;
                 }       
 
                 ci->seek_buffer(rmctx.data_offset + DATA_HEADER_SIZE);
@@ -139,12 +142,13 @@ seek_start :
                 rmctx.frame_number = 0;
 
                 /* Seek to the start of the track */
-                if (ci->seek_time == 1) {
+                if (param == 0) {
                     ci->set_elapsed(0);
                     ci->seek_complete();
+                    action = CODEC_ACTION_NULL;
                     goto seek_start;           
                 }                                                                
-                num_units = ((ci->seek_time)/(sps*1000*8/rmctx.bit_rate))/(h*(fs/sps));                    
+                num_units = (param/(sps*1000*8/rmctx.bit_rate))/(h*(fs/sps));                    
                 ci->seek_buffer(rmctx.data_offset + DATA_HEADER_SIZE + consumed * num_units);
                 bit_buffer = (uint8_t *) ci->request_buffer(&buff_size, scrambling_unit_size);
                 consumed = rm_get_packet(&bit_buffer, &rmctx, &pkt);
@@ -155,12 +159,12 @@ seek_start :
                         return CODEC_ERROR;
                     }
                     else
-                        goto done;
+                        return CODEC_OK;
                 }
 
                 packet_count = rmctx.nb_packets - rmctx.audio_pkt_cnt * num_units;
-                rmctx.frame_number = ((ci->seek_time)/(sps*1000*8/rmctx.bit_rate)); 
-                while(rmctx.audiotimestamp > (unsigned) ci->seek_time) {
+                rmctx.frame_number = (param/(sps*1000*8/rmctx.bit_rate)); 
+                while(rmctx.audiotimestamp > (unsigned) param) {
                     rmctx.audio_pkt_cnt = 0;
                     ci->seek_buffer(rmctx.data_offset + DATA_HEADER_SIZE + consumed * (num_units-1));
                     bit_buffer = (uint8_t *) ci->request_buffer(&buff_size, scrambling_unit_size); 
@@ -168,16 +172,19 @@ seek_start :
                     packet_count += rmctx.audio_pkt_cnt;
                     num_units--;
                 }
-                time_offset = ci->seek_time - rmctx.audiotimestamp;
+                time_offset = param - rmctx.audiotimestamp;
                 i = (time_offset/((sps * 8 * 1000)/rmctx.bit_rate));
                 elapsed = rmctx.audiotimestamp+(1000*8*sps/rmctx.bit_rate)*i;
                 ci->set_elapsed(elapsed);
                 ci->seek_complete(); 
             }
+
+            action = CODEC_ACTION_NULL;
+
             if(pkt.length)    
                 res = atrac3_decode_frame(rmctx.block_align, &q, &datasize, pkt.frames[i], rmctx.block_align);
             else /* indicates that there are no remaining frames */
-                goto done;
+                return CODEC_OK;
 
             if(res != rmctx.block_align) {
                 DEBUGF("codec error\n");
@@ -196,9 +203,5 @@ seek_start :
         ci->advance_buffer(consumed);
     }
 
-    done :
-    if (ci->request_next_track())
-        goto next_track;
-
-    return CODEC_OK;    
+    return CODEC_OK;
 }
diff --git a/apps/codecs/au.c b/apps/codecs/au.c
index 3f9436c9e7..e06f931cf9 100644
--- a/apps/codecs/au.c
+++ b/apps/codecs/au.c
@@ -106,9 +106,19 @@ static int convert_au_format(unsigned int encoding, struct pcm_format *fmt)
 }
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, PCM_OUTPUT_DEPTH-1);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
-    int status;
     struct pcm_format format;
     uint32_t bytesdone, decodedsamples;
     size_t n;
@@ -119,22 +129,13 @@ enum codec_status codec_main(void)
     off_t firstblockposn;     /* position of the first block in file */
     const struct pcm_codec *codec;
     int offset = 0;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, PCM_OUTPUT_DEPTH-1);
-  
-next_track:
-    status = CODEC_OK;
-
+    intptr_t param;
+ 
     if (codec_init()) {
         DEBUGF("codec_init() error\n");
-        status = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     codec_set_replaygain(ci->id3);
     
     /* Need to save offset for later use (cleared indirectly by advance_buffer) */
@@ -145,6 +146,7 @@ next_track:
     format.is_little_endian = false;
 
     /* set format */
+    ci->seek_buffer(0);
     buf = ci->request_buffer(&n, 24);
     if (n < 24 || (memcmp(buf, ".snd", 4) != 0))
     {
@@ -170,8 +172,7 @@ next_track:
         if (offset < 24)
         {
             DEBUGF("CODEC_ERROR: sun audio offset size is small: %d\n", offset);
-            status = CODEC_ERROR;
-            goto done;
+            return CODEC_ERROR;
         }
         /* data size */
         format.numbytes = get_be32(buf + 8);
@@ -182,8 +183,7 @@ next_track:
         if (format.formattag == AU_FORMAT_UNSUPPORT)
         {
             DEBUGF("CODEC_ERROR: sun audio unsupport format: %d\n", get_be32(buf + 12));
-            status = CODEC_ERROR;
-            goto done;
+            return CODEC_ERROR;
         }
         /* skip sample rate */
         format.channels = get_be32(buf + 20);
@@ -202,20 +202,17 @@ next_track:
     if (!codec)
     {
         DEBUGF("CODEC_ERROR: unsupport sun audio format: %x\n", (int)format.formattag);
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     if (!codec->set_format(&format))
     {
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     if (format.numbytes == 0) {
         DEBUGF("CODEC_ERROR: data size is 0\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* check chunksize */
@@ -225,8 +222,7 @@ next_track:
     if (format.chunksize == 0)
     {
         DEBUGF("CODEC_ERROR: chunksize is 0\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
@@ -236,8 +232,7 @@ next_track:
         ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
     } else {
         DEBUGF("CODEC_ERROR: more than 2 channels\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* make sure we're at the correct offset */
@@ -253,7 +248,6 @@ next_track:
             bytesdone      = newpos->pos;
             decodedsamples = newpos->samples;
         }
-        ci->seek_complete();
     } else {
         /* already where we need to be */
         bytesdone = 0;
@@ -263,22 +257,29 @@ next_track:
     endofstream = 0;
 
     while (!endofstream) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
-        }
 
-        if (ci->seek_time) {
+        if (action == CODEC_ACTION_SEEK_TIME) {
             /* 3rd args(read_buffer) is unnecessary in the format which Sun Audio supports.  */
-            struct pcm_pos *newpos = codec->get_seek_pos(ci->seek_time, PCM_SEEK_TIME, NULL);
+            struct pcm_pos *newpos = codec->get_seek_pos(param, PCM_SEEK_TIME, NULL);
 
             if (newpos->pos > format.numbytes)
+            {
+                ci->set_elapsed(ci->id3->length);
+                ci->seek_complete();
                 break;
+            }
+
             if (ci->seek_buffer(firstblockposn + newpos->pos))
             {
                 bytesdone      = newpos->pos;
                 decodedsamples = newpos->samples;
             }
+
+            ci->set_elapsed(decodedsamples*1000LL/ci->id3->frequency);
             ci->seek_complete();
         }
 
@@ -290,11 +291,10 @@ next_track:
             endofstream = 1;
         }
 
-        status = codec->decode(aubuf, n, samples, &bufcount);
-        if (status == CODEC_ERROR)
+        if (codec->decode(aubuf, n, samples, &bufcount) == CODEC_ERROR)
         {
             DEBUGF("codec error\n");
-            goto done;
+            return CODEC_ERROR;
         }
 
         ci->pcmbuf_insert(samples, NULL, bufcount);
@@ -308,9 +308,5 @@ next_track:
     }
 
 done:
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    return status;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/codec_crt0.c b/apps/codecs/codec_crt0.c
index cf14e460ec..33876272c6 100644
--- a/apps/codecs/codec_crt0.c
+++ b/apps/codecs/codec_crt0.c
@@ -27,39 +27,45 @@ struct codec_api *ci DATA_ATTR;
 extern unsigned char plugin_bss_start[];
 extern unsigned char plugin_end_addr[];
 
-extern enum codec_status codec_main(void);
+extern enum codec_status codec_main(enum codec_entry_call_reason reason);
 
 /* stub, the entry point is called via its reference in __header to
  * avoid warning with certain compilers */
 int _start(void) {return 0;}
 
-enum codec_status codec_start(void)
+enum codec_status codec_start(enum codec_entry_call_reason reason)
 {
 #if (CONFIG_PLATFORM & PLATFORM_NATIVE)
-#ifdef USE_IRAM
-    extern char iramcopy[], iramstart[], iramend[], iedata[], iend[];
-    size_t iram_size = iramend - iramstart;
-    size_t ibss_size = iend - iedata;
-    if (iram_size > 0 || ibss_size > 0)
+    if (reason == CODEC_LOAD)
     {
-        ci->memcpy(iramstart, iramcopy, iram_size);
-        ci->memset(iedata, 0, ibss_size);
-        /* make the icache (if it exists) up to date with the new code */
+#ifdef USE_IRAM
+        extern char iramcopy[], iramstart[], iramend[], iedata[], iend[];
+        size_t iram_size = iramend - iramstart;
+        size_t ibss_size = iend - iedata;
+        if (iram_size > 0 || ibss_size > 0)
+        {
+            ci->memcpy(iramstart, iramcopy, iram_size);
+            ci->memset(iedata, 0, ibss_size);
+            /* make the icache (if it exists) up to date with the new code */
+            ci->cpucache_invalidate();
+            /* barrier to prevent reordering iram copy and BSS clearing,
+             * because the BSS segment alias the IRAM copy.
+             */
+            asm volatile ("" ::: "memory");
+        }
+#endif /* PLUGIN_USE_IRAM */
+        ci->memset(plugin_bss_start, 0, plugin_end_addr - plugin_bss_start);
+        /* Some parts of bss may be used via a no-cache alias (at least
+         * portalplayer has this). If we don't clear the cache, those aliases
+         * may read garbage */
         ci->cpucache_invalidate();
-        /* barrier to prevent reordering iram copy and BSS clearing,
-         * because the BSS segment alias the IRAM copy.
-         */
-        asm volatile ("" ::: "memory");
     }
-#endif /* PLUGIN_USE_IRAM */
-    ci->memset(plugin_bss_start, 0, plugin_end_addr - plugin_bss_start);
-    /* Some parts of bss may be used via a no-cache alias (at least
-     * portalplayer has this). If we don't clear the cache, those aliases
-     * may read garbage */
-    ci->cpucache_invalidate();
-#endif
+#endif /* CONFIG_PLATFORM */
 
-    return codec_main();
+    /* Note: If for any reason codec_main would not be called with CODEC_LOAD
+     * because the above code failed then it must not be ever be called with
+     * any other value and some strategy to avoid doing so must be conceived */
+    return codec_main(reason);
 }
 
 #if defined(CPU_ARM) && (CONFIG_PLATFORM & PLATFORM_NATIVE)
diff --git a/apps/codecs/cook.c b/apps/codecs/cook.c
index 015618986c..a6b4a1153e 100644
--- a/apps/codecs/cook.c
+++ b/apps/codecs/cook.c
@@ -38,9 +38,9 @@ static void init_rm(RMContext *rmctx)
     memcpy(rmctx, (void*)(( (intptr_t)ci->id3->id3v2buf + 3 ) &~ 3), sizeof(RMContext));
 }
 
-/* this is the codec entry point */
-enum codec_status codec_main(void)
-{ 
+/* this is called for each file to process */
+enum codec_status codec_run(void)
+{
     static size_t buff_size;
     int datasize, res, consumed, i, time_offset;
     uint8_t *bit_buffer;
@@ -48,16 +48,14 @@ enum codec_status codec_main(void)
     uint32_t packet_count;
     int scrambling_unit_size, num_units;
     size_t resume_offset;
+    intptr_t param = 0;
+    enum codec_command_action action = CODEC_ACTION_NULL;
 
-next_track:
     if (codec_init()) {
         DEBUGF("codec init failed\n");
         return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     resume_offset = ci->id3->offset;
 
     codec_set_replaygain(ci->id3);
@@ -65,6 +63,8 @@ next_track:
     ci->memset(&pkt,0,sizeof(RMPacket));
     ci->memset(&q,0,sizeof(COOKContext));
 
+    ci->seek_buffer(0);
+
     init_rm(&rmctx);
  
     ci->configure(DSP_SET_FREQUENCY, ci->id3->frequency);
@@ -87,20 +87,21 @@ next_track:
         DEBUGF("failed to initialize cook decoder\n");
         return CODEC_ERROR;
     }
-    
+
     /* check for a mid-track resume and force a seek time accordingly */
     if(resume_offset > rmctx.data_offset + DATA_HEADER_SIZE) {
         resume_offset -= rmctx.data_offset + DATA_HEADER_SIZE;
         num_units = (int)resume_offset / scrambling_unit_size;    
         /* put number of subpackets to skip in resume_offset */
         resume_offset /= (sps + PACKET_HEADER_SIZE);
-        ci->seek_time =  (int)resume_offset * ((sps * 8 * 1000)/rmctx.bit_rate);                
+        param = (int)resume_offset * ((sps * 8 * 1000)/rmctx.bit_rate);
+        action = CODEC_ACTION_SEEK_TIME;
     }
 
     ci->set_elapsed(0);
     ci->advance_buffer(rmctx.data_offset + DATA_HEADER_SIZE);
 
-    /* The main decoder loop */  
+    /* The main decoder loop */
 seek_start :         
     while(packet_count)
     {  
@@ -112,18 +113,19 @@ seek_start :
         }
        
         for(i = 0; i < rmctx.audio_pkt_cnt*(fs/sps) ; i++)
-        { 
-            ci->yield();
-            if (ci->stop_codec || ci->new_track)
-                goto done;
+        {
+            if (action == CODEC_ACTION_NULL)
+                action = ci->get_command(&param);
 
-            if (ci->seek_time) {
-                ci->set_elapsed(ci->seek_time);
+            if (action == CODEC_ACTION_HALT)
+                return CODEC_OK;
 
+            if (action == CODEC_ACTION_SEEK_TIME) {
                 /* Do not allow seeking beyond the file's length */
-                if ((unsigned) ci->seek_time > ci->id3->length) {
+                if ((unsigned) param > ci->id3->length) {
+                    ci->set_elapsed(ci->id3->length);
                     ci->seek_complete();
-                    goto done;
+                    return CODEC_OK;
                 }       
 
                 ci->seek_buffer(rmctx.data_offset + DATA_HEADER_SIZE);
@@ -132,22 +134,24 @@ seek_start :
                 rmctx.frame_number = 0;
 
                 /* Seek to the start of the track */
-                if (ci->seek_time == 1) {
+                if (param == 0) {
                     ci->set_elapsed(0);
                     ci->seek_complete();
+                    action = CODEC_ACTION_NULL;
                     goto seek_start;           
                 }                                                                
-                num_units = ((ci->seek_time)/(sps*1000*8/rmctx.bit_rate))/(h*(fs/sps));                    
+                num_units = (param/(sps*1000*8/rmctx.bit_rate))/(h*(fs/sps));                    
                 ci->seek_buffer(rmctx.data_offset + DATA_HEADER_SIZE + consumed * num_units);
                 bit_buffer = (uint8_t *) ci->request_buffer(&buff_size, scrambling_unit_size);
                 consumed = rm_get_packet(&bit_buffer, &rmctx, &pkt);
                 if(consumed < 0) {
                      DEBUGF("rm_get_packet failed\n");
-                     return CODEC_ERROR;
+                    ci->seek_complete();
+                    return CODEC_ERROR;
                 } 
                 packet_count = rmctx.nb_packets - rmctx.audio_pkt_cnt * num_units;
-                rmctx.frame_number = ((ci->seek_time)/(sps*1000*8/rmctx.bit_rate)); 
-                while(rmctx.audiotimestamp > (unsigned) ci->seek_time) {
+                rmctx.frame_number = (param/(sps*1000*8/rmctx.bit_rate)); 
+                while(rmctx.audiotimestamp > (unsigned) param) {
                     rmctx.audio_pkt_cnt = 0;
                     ci->seek_buffer(rmctx.data_offset + DATA_HEADER_SIZE + consumed * (num_units-1));
                     bit_buffer = (uint8_t *) ci->request_buffer(&buff_size, scrambling_unit_size); 
@@ -155,11 +159,14 @@ seek_start :
                     packet_count += rmctx.audio_pkt_cnt;
                     num_units--;
                 }
-                time_offset = ci->seek_time - rmctx.audiotimestamp;
+                time_offset = param - rmctx.audiotimestamp;
                 i = (time_offset/((sps * 8 * 1000)/rmctx.bit_rate));
                 ci->set_elapsed(rmctx.audiotimestamp+(1000*8*sps/rmctx.bit_rate)*i);
                 ci->seek_complete(); 
-            }    
+            }
+
+            action = CODEC_ACTION_NULL;
+
             res = cook_decode_frame(&rmctx,&q, rm_outbuf, &datasize, pkt.frames[i], rmctx.block_align);
             rmctx.frame_number++;
 
@@ -181,9 +188,5 @@ seek_start :
         ci->advance_buffer(consumed);
     }
 
-    done :
-    if (ci->request_next_track())
-        goto next_track;
-
-    return CODEC_OK;    
+    return CODEC_OK;
 }
diff --git a/apps/codecs/flac.c b/apps/codecs/flac.c
index 89d14b98a7..a5521b584f 100644
--- a/apps/codecs/flac.c
+++ b/apps/codecs/flac.c
@@ -418,40 +418,40 @@ static bool flac_seek_offset(FLACContext* fc, uint32_t offset) {
 }
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, FLAC_OUTPUT_DEPTH-1);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     int8_t *buf;
     FLACContext fc;
-    uint32_t samplesdone = 0;
+    uint32_t samplesdone;
     uint32_t elapsedtime;
     size_t bytesleft;
     int consumed;
     int res;
     int frame;
-    int retval;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, FLAC_OUTPUT_DEPTH-1);
+    intptr_t param;
 
-next_track:
-    retval = CODEC_OK;
-        
     if (codec_init()) {
         LOGF("FLAC: Error initialising codec\n");
-        retval = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     /* Need to save offset for later use (cleared indirectly by flac_init) */
     samplesdone = ci->id3->offset;
     
     if (!flac_init(&fc,ci->id3->first_frame_offset)) {
         LOGF("FLAC: Error initialising codec\n");
-        retval = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
@@ -459,35 +459,34 @@ next_track:
                   STEREO_MONO : STEREO_NONINTERLEAVED);
     codec_set_replaygain(ci->id3);
 
-    if (samplesdone) {
-        flac_seek_offset(&fc, samplesdone);
-        samplesdone=0;
-    }
+    flac_seek_offset(&fc, samplesdone);
+    samplesdone=0;
 
     /* The main decoding loop */
     frame=0;
     buf = ci->request_buffer(&bytesleft, MAX_FRAMESIZE);
     while (bytesleft) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
-        }
 
         /* Deal with any pending seek requests */
-        if (ci->seek_time) {
-            if (flac_seek(&fc,(uint32_t)(((uint64_t)(ci->seek_time-1)
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            if (flac_seek(&fc,(uint32_t)(((uint64_t)param
                 *ci->id3->frequency)/1000))) {
                 /* Refill the input buffer */
                 buf = ci->request_buffer(&bytesleft, MAX_FRAMESIZE);
             }
+
+            ci->set_elapsed(param);
             ci->seek_complete();
         }
 
         if((res=flac_decode_frame(&fc,decoded0,decoded1,buf,
                              bytesleft,ci->yield)) < 0) {
              LOGF("FLAC: Frame %d, error %d\n",frame,res);
-             retval = CODEC_ERROR;
-             goto done;
+             return CODEC_ERROR;
         }
         consumed=fc.gb.index/8;
         frame++;
@@ -507,14 +506,7 @@ next_track:
 
         buf = ci->request_buffer(&bytesleft, MAX_FRAMESIZE);
     }
-    retval = CODEC_OK;
 
-done:
     LOGF("FLAC: Decoded %lu samples\n",(unsigned long)samplesdone);
-
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    return retval;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/lib/codeclib.c b/apps/codecs/lib/codeclib.c
index af0894c498..443c0bbdcf 100644
--- a/apps/codecs/lib/codeclib.c
+++ b/apps/codecs/lib/codeclib.c
@@ -33,6 +33,16 @@ unsigned char* mp3buf;     // The actual MP3 buffer from Rockbox
 unsigned char* mallocbuf;  // 512K from the start of MP3 buffer
 unsigned char* filebuf;    // The rest of the MP3 buffer
 
+/* this is the default codec entry point for when nothing needs to be done
+   on load or unload */
+enum codec_status __attribute__((weak))
+codec_main(enum codec_entry_call_reason reason)
+{
+    /* Nothing to do */
+    return CODEC_OK;
+    (void)reason;
+}
+
 int codec_init(void)
 {
     mem_ptr = 0;
@@ -41,7 +51,7 @@ int codec_init(void)
     return 0;
 }
 
-void codec_set_replaygain(struct mp3entry* id3)
+void codec_set_replaygain(const struct mp3entry *id3)
 {
     ci->configure(DSP_SET_TRACK_GAIN, id3->track_gain);
     ci->configure(DSP_SET_ALBUM_GAIN, id3->album_gain);
@@ -49,19 +59,6 @@ void codec_set_replaygain(struct mp3entry* id3)
     ci->configure(DSP_SET_ALBUM_PEAK, id3->album_peak);
 }
 
-/* Note: codec really needs its own private metdata copy for the current
-   track being processed in order to be stable. */
-int codec_wait_taginfo(void)
-{
-    while (!*ci->taginfo_ready && !ci->stop_codec && !ci->new_track)
-        ci->sleep(0);
-    if (ci->stop_codec)
-        return -1;
-    if (ci->new_track)
-        return 1;
-    return 0;
-}
-
 /* Various "helper functions" common to all the xxx2wav decoder plugins  */
 
 
diff --git a/apps/codecs/lib/codeclib.h b/apps/codecs/lib/codeclib.h
index 41b466ed1f..30091c5333 100644
--- a/apps/codecs/lib/codeclib.h
+++ b/apps/codecs/lib/codeclib.h
@@ -156,8 +156,7 @@ static inline unsigned int bs_generic(unsigned int v, int mode)
 /* Various codec helper functions */
 
 int codec_init(void);
-void codec_set_replaygain(struct mp3entry* id3);
-int codec_wait_taginfo(void); /* 0 = success */
+void codec_set_replaygain(const struct mp3entry *id3);
 
 #ifdef RB_PROFILE
 void __cyg_profile_func_enter(void *this_fn, void *call_site)
diff --git a/apps/codecs/mod.c b/apps/codecs/mod.c
index 4ace721a1e..3dfaac663f 100644
--- a/apps/codecs/mod.c
+++ b/apps/codecs/mod.c
@@ -1218,47 +1218,37 @@ void synthrender(int32_t *renderbuffer, int samplecount)
     }
 }
 
+/* this is the codec entry point */
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Make use of 44.1khz */
+        ci->configure(DSP_SET_FREQUENCY, 44100);
+        /* Sample depth is 28 bit host endian */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 28);
+        /* Stereo output */
+        ci->configure(DSP_SET_STEREO_MODE, STEREO_INTERLEAVED);
+    }
+
+    return CODEC_OK;
+}
 
-enum codec_status codec_main(void)
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     size_t n;
     unsigned char *modfile;
     int old_patterntableposition;
-
     int bytesdone;
+    intptr_t param;
 
-next_track:
     if (codec_init()) {
         return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto request_next_track;
-
     codec_set_replaygain(ci->id3);
 
     /* Load MOD file */
-    /*
-     * This is the save way
-
-    size_t bytesfree;
-    unsigned int filesize;
-
-    p = modfile;
-    bytesfree=sizeof(modfile);
-    while ((n = ci->read_filebuf(p, bytesfree)) > 0) {
-        p += n;
-        bytesfree -= n;
-        if (bytesfree == 0)
-           return CODEC_ERROR;
-    }
-    filesize = p-modfile;
-
-    if (filesize == 0)
-        return CODEC_ERROR;
-    */
-
-    /* Directly use mod in buffer */
     ci->seek_buffer(0);
     modfile = ci->request_buffer(&n, ci->filesize);
     if (!modfile || n < (size_t)ci->filesize) {
@@ -1268,27 +1258,22 @@ next_track:
     initmodplayer();
     loadmod(modfile);
 
-    /* Make use of 44.1khz */
-    ci->configure(DSP_SET_FREQUENCY, 44100);
-    /* Sample depth is 28 bit host endian */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 28);
-    /* Stereo output */
-    ci->configure(DSP_SET_STEREO_MODE, STEREO_INTERLEAVED);
-
     /* The main decoder loop */
     ci->set_elapsed(0);
     bytesdone = 0;
     old_patterntableposition = 0;
 
     while (1) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track)
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
 
-        if (ci->seek_time) {
-            /* New time is ready in ci->seek_time */
-            modplayer.patterntableposition = ci->seek_time/1000;
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            /* New time is ready in param */
+            modplayer.patterntableposition = param/1000;
             modplayer.currentline = 0;
+            ci->set_elapsed(modplayer.patterntableposition*1000+500);
             ci->seek_complete();
         }
 
@@ -1305,9 +1290,5 @@ next_track:
 
     }
 
-request_next_track:
-    if (ci->request_next_track())
-        goto next_track;
-
     return CODEC_OK;
 }
diff --git a/apps/codecs/mp3_enc.c b/apps/codecs/mp3_enc.c
index e7893fd14a..2f5528f74c 100644
--- a/apps/codecs/mp3_enc.c
+++ b/apps/codecs/mp3_enc.c
@@ -2584,45 +2584,46 @@ static bool enc_init(void)
     return true;
 } /* enc_init */
 
-enum codec_status codec_main(void)
+/* this is the codec entry point */
+enum codec_status codec_main(enum codec_entry_call_reason reason)
 {
-    /* Generic codec initialisation */
-    if (!enc_init())
-        return CODEC_ERROR;
+    if (reason == CODEC_LOAD) {
+        if (!enc_init())
+            return CODEC_ERROR;
+    }
+    else if (reason == CODEC_UNLOAD) {
+        /* reset parameters to initial state */
+        ci->enc_set_parameters(NULL);
+    }
+
+    return CODEC_OK;
+}
 
+/* this is called for each file to process */
+enum codec_status codec_run(void)
+{
     /* main encoding loop */
-    while (!ci->stop_codec)
+    while(ci->get_command(NULL) != CODEC_ACTION_HALT)
     {
-        char *buffer;
-
-        while ((buffer = ci->enc_get_pcm_data(pcm_chunk_size)) != NULL)
-        {
-            struct enc_chunk_hdr *chunk;
-
-            if (ci->stop_codec)
-                break;
+        char *buffer = buffer = ci->enc_get_pcm_data(pcm_chunk_size);
+        struct enc_chunk_hdr *chunk;
 
-            chunk           = ci->enc_get_chunk();
-            chunk->enc_data = ENC_CHUNK_SKIP_HDR(chunk->enc_data, chunk);
+        if(buffer == NULL)
+            continue;
 
-            encode_frame(buffer, chunk);
+        chunk           = ci->enc_get_chunk();
+        chunk->enc_data = ENC_CHUNK_SKIP_HDR(chunk->enc_data, chunk);
 
-            if (chunk->num_pcm < samp_per_frame)
-            {
-                ci->enc_unget_pcm_data(pcm_chunk_size - chunk->num_pcm*4);
-                chunk->num_pcm = samp_per_frame;
-            }
+        encode_frame(buffer, chunk);
 
-            ci->enc_finish_chunk();
-
-            ci->yield();
+        if (chunk->num_pcm < samp_per_frame)
+        {
+            ci->enc_unget_pcm_data(pcm_chunk_size - chunk->num_pcm*4);
+            chunk->num_pcm = samp_per_frame;
         }
 
-        ci->yield();
+        ci->enc_finish_chunk();
     }
 
-    /* reset parameters to initial state */
-    ci->enc_set_parameters(NULL);
-
     return CODEC_OK;
-} /* codec_start */
+}
diff --git a/apps/codecs/mpa.c b/apps/codecs/mpa.c
index 4b49775029..c9e2131450 100644
--- a/apps/codecs/mpa.c
+++ b/apps/codecs/mpa.c
@@ -268,8 +268,8 @@ static bool mad_synth_thread_create(void)
 
 static void mad_synth_thread_quit(void)
 {
-    /*mop up COP thread*/
-    die=1;
+    /* mop up COP thread */
+    die = 1;
     ci->semaphore_release(&synth_pending_sem);
     ci->thread_wait(mad_synth_thread_id);
     ci->cpucache_invalidate();
@@ -299,9 +299,30 @@ static inline void mad_synth_thread_unwait_pcm(void)
 #endif /* MPA_SYNTH_ON_COP */
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Create a decoder instance */
+        if (codec_init())
+            return CODEC_ERROR;
+
+        ci->configure(DSP_SET_SAMPLE_DEPTH, MAD_F_FRACBITS);
+
+        /* does nothing on 1 processor systems except return true */
+        if(!mad_synth_thread_create())
+            return CODEC_ERROR;
+    }
+    else if (reason == CODEC_UNLOAD) {
+        /* mop up COP thread - MT only */
+        mad_synth_thread_quit();
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
-    int status;
     size_t size;
     int file_end;
     int samples_to_skip; /* samples to skip in total for this file (at start) */
@@ -312,27 +333,12 @@ enum codec_status codec_main(void)
     unsigned long current_frequency = 0;
     int framelength;
     int padding = MAD_BUFFER_GUARD; /* to help mad decode the last frame */
-
-    if (codec_init())
-        return CODEC_ERROR;
-
-    /* Create a decoder instance */
-
-    ci->configure(DSP_SET_SAMPLE_DEPTH, MAD_F_FRACBITS);
-
-    /*does nothing on 1 processor systems except return true*/
-    if(!mad_synth_thread_create())
-        return CODEC_ERROR;
-    
-next_track:
-    status = CODEC_OK;
+    intptr_t param;
 
     /* Reinitializing seems to be necessary to avoid playback quircks when seeking. */
     init_mad();
 
     file_end = 0;
-    if (codec_wait_taginfo() != 0)
-        goto request_next_track;
 
     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
     current_frequency = ci->id3->frequency;
@@ -379,29 +385,35 @@ next_track:
 
     /* This is the decoding loop. */
     while (1) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track)
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
 
-        if (ci->seek_time) {
+        if (action == CODEC_ACTION_SEEK_TIME) {
             int newpos;
 
             /*make sure the synth thread is idle before seeking - MT only*/
             mad_synth_thread_wait_pcm();
             mad_synth_thread_unwait_pcm();
 
-            samplesdone = ((int64_t)(ci->seek_time-1))*current_frequency/1000;
+            samplesdone = ((int64_t)param)*current_frequency/1000;
 
-            if (ci->seek_time-1 == 0) {
+            if (param == 0) {
                 newpos = ci->id3->first_frame_offset;
                 samples_to_skip = start_skip;
             } else {
-                newpos = get_file_pos(ci->seek_time-1);
+                newpos = get_file_pos(param);
                 samples_to_skip = 0;
             }
 
             if (!ci->seek_buffer(newpos))
+            {
+                ci->seek_complete();
                 break;
+            }
+
+            ci->set_elapsed((samplesdone * 1000) / current_frequency);
             ci->seek_complete();
             init_mad();
             framelength = 0;
@@ -435,8 +447,7 @@ next_track:
                 continue;
             } else {
                 /* Some other unrecoverable error */
-                status = CODEC_ERROR;
-                break;
+               return CODEC_ERROR;
             }
         }
 
@@ -504,12 +515,5 @@ next_track:
                           framelength - stop_skip);
     }
 
-request_next_track:
-    if (ci->request_next_track())
-        goto next_track;
-
-    /*mop up COP thread - MT only*/
-    mad_synth_thread_quit();
-
-    return status;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/mpc.c b/apps/codecs/mpc.c
index 187c37e597..bbe2d9943b 100644
--- a/apps/codecs/mpc.c
+++ b/apps/codecs/mpc.c
@@ -52,8 +52,20 @@ static mpc_int32_t get_size_impl(mpc_reader *reader)
     return ci->filesize;
 }
 
-/* This is the codec entry point. */
-enum codec_status codec_main(void)
+/* this is the codec entry point */
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* musepack's sample representation is 18.14
+         * DSP_SET_SAMPLE_DEPTH = 14 (FRACT) + 16 (NATIVE) - 1 (SIGN) = 29 */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 29);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     mpc_int64_t samplesdone;
     uint32_t frequency;     /* 0.1 kHz accuracy */
@@ -64,39 +76,27 @@ enum codec_status codec_main(void)
     mpc_streaminfo info;
     mpc_frame_info frame;
     mpc_demux *demux = NULL;
-    int retval;
+    intptr_t param;
     
     frame.buffer = sample_buffer;
-    
-    /* musepack's sample representation is 18.14
-     * DSP_SET_SAMPLE_DEPTH = 14 (FRACT) + 16 (NATIVE) - 1 (SIGN) = 29 */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 29);
-    
+
     /* Create a decoder instance */
     reader.read     = read_impl;
     reader.seek     = seek_impl;
     reader.tell     = tell_impl;
     reader.get_size = get_size_impl;
 
-next_track:
-    retval = CODEC_OK;
-
     if (codec_init()) 
-    {
-        retval = CODEC_ERROR;
-        goto exit;
-    }
+        return CODEC_ERROR;
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
+    /* Prep position */
+    ci->seek_buffer(0);
 
     /* Initialize demux/decoder. */
     demux = mpc_demux_init(&reader);
     if (NULL == demux)
-    {
-        retval = CODEC_ERROR;
-        goto done;
-    }
+        return CODEC_ERROR;
+
     /* Read file's streaminfo data. */
     mpc_demux_get_info(demux, &info);
     
@@ -117,11 +117,8 @@ next_track:
         ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
     else if (info.channels == 1)
         ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
-    else 
-    {
-       retval = CODEC_ERROR;
-       goto done;
-    }
+    else
+        return CODEC_ERROR;
     
     codec_set_replaygain(ci->id3);
 
@@ -142,21 +139,24 @@ next_track:
     /* This is the decoding loop. */
     do 
     {
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
+            return CODEC_OK;
+
         /* Complete seek handler. */
-        if (ci->seek_time) 
+        if (action == CODEC_ACTION_SEEK_TIME) 
         {
-            mpc_int64_t new_offset = ((ci->seek_time - 1)/10)*frequency;
+            mpc_int64_t new_offset = (param/10)*frequency;
             if (mpc_demux_seek_sample(demux, new_offset) == MPC_STATUS_OK) 
             {
                 samplesdone = new_offset;
-                ci->set_elapsed(ci->seek_time);
             }
+
+            elapsed_time = (samplesdone*10)/frequency;
+            ci->set_elapsed(elapsed_time);
             ci->seek_complete();
         }
-        
-        /* Stop or skip occured, exit decoding loop. */
-        if (ci->stop_codec || ci->new_track)
-            break;
 
         /* Decode one frame. */
         status = mpc_demux_decode(demux, &frame);
@@ -164,8 +164,7 @@ next_track:
         if (frame.bits == -1)
         {
             /* Decoding error, exit decoding loop. */
-            retval = (status == MPC_STATUS_OK) ? CODEC_OK : CODEC_ERROR;
-            goto done;
+            return (status == MPC_STATUS_OK) ? CODEC_OK : CODEC_ERROR;
         } 
         else 
         {
@@ -181,11 +180,4 @@ next_track:
             ci->set_offset( (samplesdone * byterate)/(frequency*100) );
         }
     } while (true);
-
-done:
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    return retval;
 }
diff --git a/apps/codecs/nsf.c b/apps/codecs/nsf.c
index 2f37da81d2..72f6974214 100644
--- a/apps/codecs/nsf.c
+++ b/apps/codecs/nsf.c
@@ -4307,46 +4307,44 @@ static void set_codec_track(int t, int d) {
         nSilenceTrackMS=5000;
         SetFadeTime(track,track+fade, fNSFPlaybackSpeed,def);
     }
-    ci->id3->elapsed=d*1000; /* d is track no to display */
+    ci->set_elapsed(d*1000); /* d is track no to display */
 }
 
+/** Operational info **/
+static int track = 0;
+static char last_path[MAX_PATH];
+static int dontresettrack = 0;
+
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* we only render 16 bits, 44.1KHz, Stereo */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 16);
+        ci->configure(DSP_SET_FREQUENCY, 44100);
+        ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
+
+        RebuildOutputTables();
+    }
+
+    return CODEC_OK;
+}
+    
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     int written;
     uint8_t *buf;
     size_t n;
     int endofstream; /* end of stream flag */
-    int track;
-    int dontresettrack;
-    char last_path[MAX_PATH];
-    int usingplaylist;
-
-    /* we only render 16 bits */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 16);
-
-    ci->configure(DSP_SET_FREQUENCY, 44100);
-    ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
-    
-    RebuildOutputTables();
-
-    dontresettrack=0;
-    last_path[0]='\0';
-    track=0;
+    int usingplaylist = 0;
     
-next_track:
-    usingplaylist=0;
     DEBUGF("NSF: next_track\n");
     if (codec_init()) {
         return CODEC_ERROR;
     }
     DEBUGF("NSF: after init\n");
     
-
-    /* wait for track info to load */
-    if (codec_wait_taginfo() != 0)
-        goto request_next_track;
-        
     codec_set_replaygain(ci->id3);
         
     /* Read the entire file */
@@ -4408,22 +4406,27 @@ init_nsf:
     reset_profile_timers();
     
     while (!endofstream) {
+        intptr_t param;
+        enum codec_command_action action = ci->get_command(&param);
 
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
+        if (action == CODEC_ACTION_HALT)
             break;
-        }
 
-        if (ci->seek_time >0) {
-            track=ci->seek_time/1000;
-            if (usingplaylist) {
-                if (track>=nPlaylistSize) break;
-            } else {
-                if (track>=nTrackCount) break;
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            if (param > 0) {
+                track=param/1000;
+                if (usingplaylist) {
+                    if (track>=nPlaylistSize) break;
+                } else {
+                    if (track>=nTrackCount) break;
+                }
+                dontresettrack=1;
+                ci->seek_complete();
+                goto init_nsf;
+            }
+            else {
+                ci->seek_complete();
             }
-            ci->seek_complete();
-            dontresettrack=1;
-            goto init_nsf;
         }
 
         ENTER_TIMER(total);
@@ -4449,22 +4452,17 @@ init_nsf:
     
     print_timers(last_path,track);
 
-request_next_track:
-    if (ci->request_next_track()) {
     if (ci->global_settings->repeat_mode==REPEAT_ONE) {
         /* in repeat one mode just advance to the next track */
         track++;
         if (track>=nTrackCount) track=0;
         dontresettrack=1;
         /* at this point we can't tell if another file has been selected */
-        goto next_track;
     } else {
         /* otherwise do a proper load of the next file */
         dontresettrack=0;
         last_path[0]='\0';
     }
-    goto next_track; /* when we fall through here we'll reload the file */
-    }
     
     return CODEC_OK;
 }
diff --git a/apps/codecs/raac.c b/apps/codecs/raac.c
index b322ae7df3..4b73f41462 100644
--- a/apps/codecs/raac.c
+++ b/apps/codecs/raac.c
@@ -35,8 +35,21 @@ static void init_rm(RMContext *rmctx)
 
 static RMContext rmctx;
 static RMPacket pkt;
+
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 29);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     static NeAACDecFrameInfo frame_info;
     NeAACDecHandle decoder;
@@ -49,26 +62,21 @@ enum codec_status codec_main(void)
     unsigned char c = 0; /* channels */
     int playback_on = -1;
     size_t resume_offset;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 29);
-
-next_track:
-    err = CODEC_OK;
+    intptr_t param;
+    enum codec_command_action action = CODEC_ACTION_NULL;
 
     if (codec_init()) {
         DEBUGF("FAAD: Codec init error\n");
         return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     resume_offset = ci->id3->offset;
 
     ci->memset(&rmctx,0,sizeof(RMContext));
     ci->memset(&pkt,0,sizeof(RMPacket));
+
+    ci->seek_buffer(0);
+
     init_rm(&rmctx);    
     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
     codec_set_replaygain(ci->id3);
@@ -78,9 +86,9 @@ next_track:
     
     if (!decoder) {
         DEBUGF("FAAD: Decode open error\n");
-        err = CODEC_ERROR;
-        goto done;
-    }   
+        return CODEC_ERROR;
+    }
+
     NeAACDecConfigurationPtr conf = NeAACDecGetCurrentConfiguration(decoder);
     conf->outputFormat = FAAD_FMT_16BIT; /* irrelevant, we don't convert */
     NeAACDecSetConfiguration(decoder, conf);    
@@ -91,8 +99,7 @@ next_track:
    
     if (err) {
         DEBUGF("FAAD: DecInit: %d, %d\n", err, decoder->object_type);
-        err = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
     
     /* check for a mid-track resume and force a seek time accordingly */
@@ -100,36 +107,38 @@ next_track:
         resume_offset -= rmctx.data_offset + DATA_HEADER_SIZE;
         /* put number of subpackets to skip in resume_offset */
         resume_offset /= (rmctx.block_align + PACKET_HEADER_SIZE);
-        ci->seek_time =  (int)resume_offset * ((rmctx.block_align * 8 * 1000)/rmctx.bit_rate);                
+        param = (int)resume_offset * ((rmctx.block_align * 8 * 1000)/rmctx.bit_rate);
+        action = CODEC_ACTION_SEEK_TIME;
     }
-    
-    ci->id3->frequency = s;    
+
+    ci->id3->frequency = s; /* FIXME: Won't get it to the UI */    
     ci->set_elapsed(0);
     ci->advance_buffer(rmctx.data_offset + DATA_HEADER_SIZE);
 
     /* The main decoding loop */
-seek_start:
     while (1) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
+        if (action == CODEC_ACTION_NULL)
+            action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
-        }
 
-        if (ci->seek_time) {            
-            
+        if (action == CODEC_ACTION_SEEK_TIME) {
             /* Do not allow seeking beyond the file's length */
-            if ((unsigned) ci->seek_time > ci->id3->length) {
+            if ((unsigned) param > ci->id3->length) {
+                ci->set_elapsed(ci->id3->length);
                 ci->seek_complete();
-                goto done;
+                break;
             }       
 
             ci->seek_buffer(rmctx.data_offset + DATA_HEADER_SIZE);            
 
             /* Seek to the start of the track */
-            if (ci->seek_time == 1) {
+            if (param == 0) {
                 ci->set_elapsed(0);
                 ci->seek_complete();
-                goto seek_start;           
+                action = CODEC_ACTION_NULL;
+                continue;          
             }
             
             skipped = 0;                                                                                       
@@ -141,21 +150,30 @@ seek_start:
                     if(playback_on == -1) {
                     /* Error only if packet-parsing failed and playback hadn't started */
                         DEBUGF("rm_get_packet failed\n");
+                        ci->seek_complete();
                         return CODEC_ERROR;
                     }
-                    else
-                        goto done;
+                    else {
+                        ci->seek_complete();
+                        return CODEC_OK;
+                    }
                 }
                 skipped += pkt.length;
-                if(pkt.timestamp > (unsigned)ci->seek_time) break;                
+
+                if(pkt.timestamp > (unsigned)param)
+                    break;
+                
                 ci->advance_buffer(pkt.length);
             }           
             ci->seek_buffer(pkt_offset + rmctx.data_offset + DATA_HEADER_SIZE);
             buffer = ci->request_buffer(&n,rmctx.audio_framesize + 1000);
             NeAACDecPostSeekReset(decoder, decoder->frame);
+            ci->set_elapsed(pkt.timestamp);
             ci->seek_complete();            
         }
 
+        action = CODEC_ACTION_NULL;
+
         /* Request the required number of bytes from the input buffer */ 
         buffer=ci->request_buffer(&n,rmctx.audio_framesize + 1000);        
         consumed = rm_get_packet(&buffer, &rmctx, &pkt);
@@ -167,20 +185,20 @@ seek_start:
                 return CODEC_ERROR;
             }
             else
-                goto done;
+                break;
         }
         
         playback_on = 1;
         if (pkt.timestamp >= ci->id3->length)
-            goto done;
+            break;
+
         /* Decode one block - returned samples will be host-endian */                           
         for(i = 0; i < rmctx.sub_packet_cnt; i++) {
             ret = NeAACDecDecode(decoder, &frame_info, buffer, rmctx.sub_packet_lengths[i]);
             buffer += rmctx.sub_packet_lengths[i];                      
             if (frame_info.error > 0) {
                 DEBUGF("FAAD: decode error '%s'\n", NeAACDecGetErrorMessage(frame_info.error));
-                err = CODEC_ERROR;
-                goto exit;
+                return CODEC_ERROR;
             }
             ci->pcmbuf_insert(decoder->time_out[0],
                               decoder->time_out[1],
@@ -191,11 +209,5 @@ seek_start:
         ci->advance_buffer(pkt.length);              
     }
 
-done:
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    return err;
+    return CODEC_OK;
 }
- 
diff --git a/apps/codecs/shorten.c b/apps/codecs/shorten.c
index 83a9c34da8..db66991679 100644
--- a/apps/codecs/shorten.c
+++ b/apps/codecs/shorten.c
@@ -37,7 +37,19 @@ static int32_t offset1[MAX_OFFSET_SIZE] IBSS_ATTR;
 static int8_t ibuf[MAX_BUFFER_SIZE] IBSS_ATTR;
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
+        ci->configure(DSP_SET_SAMPLE_DEPTH, SHN_OUTPUT_DEPTH-1);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     ShortenContext sc;
     uint32_t samplesdone;
@@ -45,21 +57,14 @@ enum codec_status codec_main(void)
     int8_t *buf;
     int consumed, res, nsamples;
     size_t bytesleft;
+    intptr_t param;
 
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
-    ci->configure(DSP_SET_SAMPLE_DEPTH, SHN_OUTPUT_DEPTH-1);
-    
-next_track:
     /* Codec initialization */
     if (codec_init()) {
         LOGF("Shorten: codec_init error\n");
         return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto request_next_track;
-
     codec_set_replaygain(ci->id3);
 
     /* Shorten decoder initialization */
@@ -103,14 +108,15 @@ seek_start:
     samplesdone = 0;
     buf = ci->request_buffer(&bytesleft, MAX_BUFFER_SIZE);
     while (bytesleft) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
-        }
 
         /* Seek to start of track */
-        if (ci->seek_time == 1) {
-            if (ci->seek_buffer(sc.header_bits/8 + ci->id3->first_frame_offset)) {
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            if (param == 0 &&
+                ci->seek_buffer(sc.header_bits/8 + ci->id3->first_frame_offset)) {
                 sc.bitindex = sc.header_bits - 8*(sc.header_bits/8);
                 ci->set_elapsed(0);
                 ci->seek_complete();
@@ -128,7 +134,7 @@ seek_start:
         if (res == FN_ERROR) {
             LOGF("Shorten: shorten_decode_frames error (%lu)\n",
                 (unsigned long)samplesdone);
-            break;
+            return CODEC_ERROR;
         } else {
             /* Insert decoded samples in pcmbuf */
             if (nsamples) {
@@ -153,9 +159,5 @@ seek_start:
         sc.bitindex = sc.gb.index - 8*consumed;
     }
 
-request_next_track:
-    if (ci->request_next_track())
-        goto next_track;
-
     return CODEC_OK;
 }
diff --git a/apps/codecs/sid.c b/apps/codecs/sid.c
index 52c1289fff..0edbabe0b6 100644
--- a/apps/codecs/sid.c
+++ b/apps/codecs/sid.c
@@ -1203,34 +1203,47 @@ unsigned short LoadSIDFromMemory(void *pSidData, unsigned short *load_addr,
     return *load_addr;
 }
 
+static int nSamplesRendered = 0;
+static int nSamplesPerCall = 882;  /* This is PAL SID single speed (44100/50Hz) */
+static int nSamplesToRender = 0;
 
-enum codec_status codec_main(void)
+/* this is the codec entry point */
+enum codec_status codec_main(enum codec_entry_call_reason reason)
 {
-    unsigned int filesize;
+    if (reason == CODEC_LOAD) {
+        /* Make use of 44.1khz */
+        ci->configure(DSP_SWITCH_FREQUENCY, 44100);
+        /* Sample depth is 28 bit host endian */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 28);
+        /* Mono output */
+        ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
+    }
+
+    return CODEC_OK;
+}
 
+/* this is called for each file to process */
+enum codec_status codec_run(void)
+{
+    unsigned int filesize;
     unsigned short load_addr, init_addr, play_addr;
     unsigned char subSongsMax, subSong, song_speed;
+    intptr_t param;
 
-    int nSamplesRendered = 0;
-    int nSamplesPerCall = 882;  /* This is PAL SID single speed (44100/50Hz) */
-    int nSamplesToRender = 0;
-
-next_track:
     if (codec_init()) {
         return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto request_next_track;
-
     codec_set_replaygain(ci->id3);
     
     /* Load SID file the read_filebuf callback will return the full requested
-     * size if at all possible, so there is no need to loop */    
+     * size if at all possible, so there is no need to loop */
+    ci->seek_buffer(0);
     filesize = ci->read_filebuf(sidfile, sizeof(sidfile));
 
-    if (filesize == 0)
+    if (filesize == 0) {
         return CODEC_ERROR;
+    }
     
     c64Init(44100);
     LoadSIDFromMemory(sidfile, &load_addr, &init_addr, &play_addr,
@@ -1239,37 +1252,30 @@ next_track:
     cpuJSR(init_addr, subSong);     /* Start the song initialize */
     
 
-    /* Make use of 44.1khz */
-    ci->configure(DSP_SWITCH_FREQUENCY, 44100);
-    /* Sample depth is 28 bit host endian */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 28);
-    /* Mono output */
-    ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
-
-    
     /* Set the elapsed time to the current subsong (in seconds) */
     ci->set_elapsed(subSong*1000);
 
     /* The main decoder loop */    
     while (1) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track)
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
 
-        if (ci->seek_time) {
-            /* New time is ready in ci->seek_time */
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            /* New time is ready in param */
 
             /* Start playing from scratch */
             c64Init(44100);
-            LoadSIDFromMemory(sidfile, &load_addr, &init_addr, &play_addr, &subSongsMax, &subSong, &song_speed, filesize);
-            sidPoke(24, 15);                /* Turn on full volume */            
-            subSong = ci->seek_time / 1000; /* Now use the current seek time in seconds as subsong */
-            cpuJSR(init_addr, subSong);     /* Start the song initialize */
-            nSamplesToRender = 0;           /* Start the rendering from scratch */
-            
-            ci->seek_complete();
+            LoadSIDFromMemory(sidfile, &load_addr, &init_addr, &play_addr,
+                              &subSongsMax, &subSong, &song_speed, filesize);
+            sidPoke(24, 15);            /* Turn on full volume */            
+            subSong = param / 1000;     /* Now use the current seek time in seconds as subsong */
+            cpuJSR(init_addr, subSong); /* Start the song initialize */
+            nSamplesToRender = 0;       /* Start the rendering from scratch */
 
             /* Set the elapsed time to the current subsong (in seconds) */
+            ci->seek_complete();
             ci->set_elapsed(subSong*1000);
         }
         
@@ -1306,9 +1312,5 @@ next_track:
         ci->pcmbuf_insert(samples, NULL, CHUNK_SIZE);
     }
 
-request_next_track:
-    if (ci->request_next_track())
-        goto next_track;
-
     return CODEC_OK;
 }
diff --git a/apps/codecs/smaf.c b/apps/codecs/smaf.c
index 3e8a41387d..9211daa9aa 100644
--- a/apps/codecs/smaf.c
+++ b/apps/codecs/smaf.c
@@ -332,9 +332,20 @@ static uint8_t *read_buffer(size_t *realsize)
     return buffer;
 }
 
-enum codec_status codec_main(void)
+/* this is the codec entry point */
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, PCM_OUTPUT_DEPTH-1);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
-    int status;
     uint32_t decodedsamples;
     size_t n;
     int bufcount;
@@ -342,20 +353,10 @@ enum codec_status codec_main(void)
     uint8_t *smafbuf;
     off_t firstblockposn;     /* position of the first block in file */
     const struct pcm_codec *codec;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, PCM_OUTPUT_DEPTH-1);
+    intptr_t param;
   
-next_track:
-    status = CODEC_OK;
-
-    if (codec_init()) {
-        status = CODEC_ERROR;
-        goto exit;
-    }
-
-    if (codec_wait_taginfo() != 0)
-        goto done;
+    if (codec_init())
+        return CODEC_ERROR;
 
     codec_set_replaygain(ci->id3);
 
@@ -365,24 +366,22 @@ next_track:
     decodedsamples = 0;
     codec = 0;
 
+    ci->seek_buffer(0);
     if (!parse_header(&format, &firstblockposn))
     {
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     codec = get_codec(format.formattag);
     if (codec == 0)
     {
         DEBUGF("CODEC_ERROR: unsupport audio format: 0x%x\n", (int)format.formattag);
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     if (!codec->set_format(&format))
     {
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* check chunksize */
@@ -392,8 +391,7 @@ next_track:
     if (format.chunksize == 0)
     {
         DEBUGF("CODEC_ERROR: chunksize is 0\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
@@ -404,12 +402,10 @@ next_track:
         ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
     } else {
         DEBUGF("CODEC_ERROR: more than 2 channels unsupported\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     ci->seek_buffer(firstblockposn);
-    ci->seek_complete();
 
     /* make sure we're at the correct offset */
     if (bytesdone > (uint32_t) firstblockposn)
@@ -419,13 +415,13 @@ next_track:
                                                      PCM_SEEK_POS, &read_buffer);
 
         if (newpos->pos > format.numbytes)
-            goto done;
+            return CODEC_OK;
+
         if (ci->seek_buffer(firstblockposn + newpos->pos))
         {
             bytesdone      = newpos->pos;
             decodedsamples = newpos->samples;
         }
-        ci->seek_complete();
     }
     else
     {
@@ -437,23 +433,32 @@ next_track:
     endofstream = 0;
 
     while (!endofstream) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track)
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
 
-        if (ci->seek_time) {
-            struct pcm_pos *newpos = codec->get_seek_pos(ci->seek_time, PCM_SEEK_TIME,
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            struct pcm_pos *newpos = codec->get_seek_pos(param, PCM_SEEK_TIME,
                                                          &read_buffer);
 
             if (newpos->pos > format.numbytes)
+            {
+                ci->set_elapsed(ci->id3->length);
+                ci->seek_complete();
                 break;
+            }
+
             if (ci->seek_buffer(firstblockposn + newpos->pos))
             {
                 bytesdone      = newpos->pos;
                 decodedsamples = newpos->samples;
             }
+
+            ci->set_elapsed(decodedsamples*1000LL/ci->id3->frequency);
             ci->seek_complete();
         }
+
         smafbuf = (uint8_t *)ci->request_buffer(&n, format.chunksize);
 
         if (n == 0)
@@ -464,11 +469,10 @@ next_track:
             endofstream = 1;
         }
 
-        status = codec->decode(smafbuf, n, samples, &bufcount);
-        if (status == CODEC_ERROR)
+        if (codec->decode(smafbuf, n, samples, &bufcount) == CODEC_ERROR)
         {
             DEBUGF("codec error\n");
-            goto done;
+            return CODEC_ERROR;
         }
 
         ci->pcmbuf_insert(samples, NULL, bufcount);
@@ -482,11 +486,5 @@ next_track:
         ci->set_elapsed(decodedsamples*1000LL/ci->id3->frequency);
     }
 
-done:
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    return status;
+    return CODEC_OK;
 }
-
diff --git a/apps/codecs/spc.c b/apps/codecs/spc.c
index 4db2878964..1b49761810 100644
--- a/apps/codecs/spc.c
+++ b/apps/codecs/spc.c
@@ -260,14 +260,6 @@ static inline void samples_release_rdbuf(void)
 static inline int32_t * samples_get_rdbuf(void)
 {
     ci->semaphore_wait(&sample_queue.emu_sem_head, TIMEOUT_BLOCK);
-
-    if (ci->stop_codec || ci->new_track)
-    {
-        /* Told to stop. Buffer must be released. */
-        samples_release_rdbuf();
-        return NULL;
-    }
-
     return sample_queue.wav_chunk[sample_queue.head & WAV_CHUNK_MASK].audio;
 }
 
@@ -390,11 +382,10 @@ static inline void spc_emu_quit(void)
     }
 }
 
-static inline bool spc_play_get_samples(int32_t **samples)
+static inline int32_t * spc_play_get_samples(void)
 {
     /* obtain filled samples buffer */
-    *samples = samples_get_rdbuf();
-    return *samples != NULL;
+    return samples_get_rdbuf();
 }
 
 static inline void spc_play_send_samples(int32_t *samples)
@@ -433,15 +424,14 @@ static inline void spc_play_send_samples(int32_t *samples)
 #define spc_emu_quit()
 #define samples_release_rdbuf()
 
-static inline bool spc_play_get_samples(int32_t **samples)
+static inline int32_t * spc_play_get_samples(void)
 {
     ENTER_TIMER(render);
     /* fill samples buffer */
     if ( SPC_play(&spc_emu,WAV_CHUNK_SIZE*2,wav_chunk) )
         assert( false );
     EXIT_TIMER(render);
-    *samples = wav_chunk;
-    return true;
+    return wav_chunk;
 }
 #endif /* SPC_DUAL_CORE */
 
@@ -454,6 +444,7 @@ static int play_track( void )
     unsigned long fadeendsample = (ID666.length+ID666.fade)*(long long) SAMPLE_RATE/1000;
     int fadedec = 0;
     int fadevol = 0x7fffffffl;
+    intptr_t param;
     
     if (fadeendsample>fadestartsample)
         fadedec=0x7fffffffl/(fadeendsample-fadestartsample)+1;
@@ -462,25 +453,26 @@ static int play_track( void )
 
     while ( 1 )
     {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
-        }
 
-        if (ci->seek_time) {
+        if (action == CODEC_ACTION_SEEK_TIME) {
             int curtime = sampleswritten*1000LL/SAMPLE_RATE;
-            DEBUGF("seek to %ld\ncurrently at %d\n",ci->seek_time,curtime);
-            if (ci->seek_time < curtime) {
+            DEBUGF("seek to %ld\ncurrently at %d\n", (long)param, curtime);
+            if (param < curtime) {
                 DEBUGF("seek backwards = reset\n");
+                ci->set_elapsed(0);
                 ci->seek_complete();
                 return 1;
             }
+
+            ci->set_elapsed(curtime);
             ci->seek_complete();
         }
 
-        int32_t *samples;
-        if (!spc_play_get_samples(&samples))
-            break;
+        int32_t *samples = spc_play_get_samples();
 
         sampleswritten += WAV_CHUNK_SIZE;
 
@@ -532,67 +524,61 @@ static int play_track( void )
 }
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
 {
-    enum codec_status stat = CODEC_ERROR;
-
-    if (!spc_emu_start())
-        goto codec_quit;
-
-    do
-    {
-        DEBUGF("SPC: next_track\n");
-        if (codec_init()) {
-            goto codec_quit;
-        }
-        DEBUGF("SPC: after init\n");
+    if (reason == CODEC_LOAD) {
+        if (!spc_emu_start())
+            return CODEC_ERROR;
 
         ci->configure(DSP_SET_SAMPLE_DEPTH, 24);
         ci->configure(DSP_SET_FREQUENCY, SAMPLE_RATE);
         ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
+    }
+    else if (reason == CODEC_UNLOAD) {
+        spc_emu_quit();
+    }
 
-        /* wait for track info to load */
-        if (codec_wait_taginfo() != 0)
-            continue;
-
-        codec_set_replaygain(ci->id3);
+    return CODEC_OK;
+}
 
-        /* Read the entire file */
-        DEBUGF("SPC: request initial buffer\n");
-        ci->seek_buffer(0);
-        size_t buffersize;
-        uint8_t* buffer = ci->request_buffer(&buffersize, ci->filesize);
-        if (!buffer) {
-            goto codec_quit;
+/* this is called for each file to process */
+enum codec_status codec_run(void)
+{
+    DEBUGF("SPC: next_track\n");
+    if (codec_init())
+        return CODEC_ERROR;
+    DEBUGF("SPC: after init\n");
+
+    codec_set_replaygain(ci->id3);
+
+    /* Read the entire file */
+    DEBUGF("SPC: request initial buffer\n");
+    ci->seek_buffer(0);
+    size_t buffersize;
+    uint8_t* buffer = ci->request_buffer(&buffersize, ci->filesize);
+    if (!buffer)
+        return CODEC_ERROR;
+
+    DEBUGF("SPC: read size = 0x%lx\n",(unsigned long)buffersize);
+    do
+    {
+        if (load_spc_buffer(buffer, buffersize)) {
+            DEBUGF("SPC load failure\n");
+            return CODEC_ERROR;
         }
 
-        DEBUGF("SPC: read size = 0x%lx\n",(unsigned long)buffersize);
-        do
-        {
-            if (load_spc_buffer(buffer, buffersize)) {
-                DEBUGF("SPC load failure\n");
-                goto codec_quit;
-            }
-
-            LoadID666(buffer+0x2e);
+        LoadID666(buffer+0x2e);
 
-            if (ci->global_settings->repeat_mode!=REPEAT_ONE && ID666.length==0) {
-                ID666.length=3*60*1000; /* 3 minutes */
-                ID666.fade=5*1000; /* 5 seconds */
-            }
-
-            reset_profile_timers();
+        if (ci->global_settings->repeat_mode!=REPEAT_ONE && ID666.length==0) {
+            ID666.length=3*60*1000; /* 3 minutes */
+            ID666.fade=5*1000; /* 5 seconds */
         }
-        while ( play_track() );
 
-        print_timers(ci->id3->path);
+        reset_profile_timers();
     }
-    while ( ci->request_next_track() );
+    while ( play_track() );
 
-    stat = CODEC_OK;
+    print_timers(ci->id3->path);
 
-codec_quit:
-    spc_emu_quit();
-    
-    return stat;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/speex.c b/apps/codecs/speex.c
index 7a1efa9753..e394efc3d5 100644
--- a/apps/codecs/speex.c
+++ b/apps/codecs/speex.c
@@ -367,11 +367,12 @@ static void *process_header(spx_ogg_packet *op,
     return st;
 }
 
-/* this is the codec entry point */
-enum codec_status codec_main(void)
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
+    int error = CODEC_ERROR;
+
     SpeexBits bits;
-    int error;
     int eof = 0;
     spx_ogg_sync_state oy;
     spx_ogg_page og;
@@ -383,7 +384,7 @@ enum codec_status codec_main(void)
     int eos = 0;
     SpeexStereoState *stereo;
     int channels = -1;
-    int rate = 0, samplerate = 0;
+    int samplerate = 0;
     int extra_headers = 0;
     int stream_init = 0;
     int page_nb_packets, frame_size, packet_count = 0;
@@ -392,26 +393,22 @@ enum codec_status codec_main(void)
     unsigned long strtoffset = 0;
     void *st = NULL;
     int j = 0;
+    intptr_t param;
 
     memset(&bits, 0, sizeof(bits));
     memset(&oy, 0, sizeof(oy));
 
     /* Ogg handling still uses mallocs, so reset the malloc buffer per track */
-next_track:
-    error = CODEC_OK;
-
     if (codec_init()) {
-        error = CODEC_ERROR;
         goto exit;
     }
 
+    ci->seek_buffer(0);
+
     stereo = speex_stereo_state_init();
     spx_ogg_sync_init(&oy);
     spx_ogg_alloc_buffer(&oy,2*CHUNKSIZE);
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     strtoffset = ci->id3->offset;
 
     samplerate = ci->id3->frequency; 
@@ -419,30 +416,32 @@ next_track:
 
     eof = 0;
     while (!eof) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track)
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
 
         /*seek (seeks to the page before the position) */
-        if (ci->seek_time) {
+        if (action == CODEC_ACTION_SEEK_TIME) {
             if(samplerate!=0&&packet_count>1){
                 LOGF("Speex seek page:%lld,%lld,%ld,%lld,%d\n",
-                     ((spx_int64_t)ci->seek_time/1000) *
+                     ((spx_int64_t)param/1000) *
                      (spx_int64_t)samplerate,
-                     page_granule, ci->seek_time,
+                     page_granule, param,
                      (page_granule/samplerate)*1000, samplerate);
 
-                speex_seek_page_granule(((spx_int64_t)ci->seek_time/1000) *
+                speex_seek_page_granule(((spx_int64_t)param/1000) *
                                         (spx_int64_t)samplerate,
                                         page_granule, &oy, headerssize);
-                ci->seek_complete();
             }
+
+            ci->set_elapsed(param);
+            ci->seek_complete();
         }
 
 next_page:
         /*Get the ogg buffer for writing*/
         if(get_more_data(&oy)<1){/*read error*/
-            error=CODEC_ERROR;
             goto done;
         }
 
@@ -477,8 +476,7 @@ next_page:
                         nframes=1;
 
                     if (!st){
-                        error=CODEC_ERROR;
-                        goto exit;
+                        goto done;
                     }
 
                     ci->configure(DSP_SET_FREQUENCY, ci->id3->frequency);
@@ -557,31 +555,18 @@ next_page:
     }
 
 done:
-    if (ci->request_next_track()) {
-
-        /* Clean things up for the next track */
+    /* Clean things up for the next track */
+    speex_bits_destroy(&bits);
 
+    if (st)
         if (st)
             speex_decoder_destroy(st);
 
-        if (stream_init == 1)
-            spx_ogg_stream_reset(&os);
-
-        spx_ogg_sync_reset(&oy);
-
-        cur_granule = stream_init = rate = samplerate = headerssize 
-            = packet_count = eos = 0;
-
-        goto next_track;
-    }
-
-exit:
-    speex_bits_destroy(&bits);
-
     if (stream_init)
        spx_ogg_stream_destroy(&os);
 
     spx_ogg_sync_destroy(&oy);
 
+exit:
     return error;
 }
diff --git a/apps/codecs/tta.c b/apps/codecs/tta.c
index 1d0846ea61..c75f2b0a57 100644
--- a/apps/codecs/tta.c
+++ b/apps/codecs/tta.c
@@ -34,36 +34,36 @@ CODEC_HEADER
 static int32_t samples[PCM_BUFFER_LENGTH * 2] IBSS_ATTR;
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, TTA_OUTPUT_DEPTH - 1);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     tta_info info;
-    int status;
     unsigned int decodedsamples;
     int endofstream;
     int new_pos = 0;
     int sample_count;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, TTA_OUTPUT_DEPTH - 1);
+    intptr_t param;
   
-next_track:
-    status = CODEC_OK;
-
     if (codec_init())
     {
         DEBUGF("codec_init() error\n");
-        status = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
+    ci->seek_buffer(0);
 
     if (set_tta_info(&info) < 0 || player_init(&info) < 0)
-    {
-        status = CODEC_ERROR;
-        goto exit;
-    }
+        return CODEC_ERROR;
 
     codec_set_replaygain(ci->id3);
 
@@ -74,8 +74,8 @@ next_track:
         ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
     } else {
         DEBUGF("CODEC_ERROR: more than 2 channels\n");
-        status = CODEC_ERROR;
-        goto done;
+        player_stop();
+        return CODEC_ERROR;
     }
 
     /* The main decoder loop */
@@ -88,31 +88,31 @@ next_track:
         new_pos = set_position(ci->id3->offset, TTA_SEEK_POS);
         if (new_pos >= 0)
             decodedsamples = new_pos;
-        ci->seek_complete();
     }
 
     while (!endofstream)
     {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track)
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
 
-        if (ci->seek_time)
+        if (action == CODEC_ACTION_SEEK_TIME)
         {
-            new_pos = set_position(ci->seek_time / SEEK_STEP, TTA_SEEK_TIME);
+            new_pos = set_position(param / SEEK_STEP, TTA_SEEK_TIME);
             if (new_pos >= 0)
             {
                 decodedsamples = new_pos;
-                ci->seek_complete();
             }
+
+            ci->set_elapsed((uint64_t)info.LENGTH * 1000 * decodedsamples / info.DATALENGTH);
+            ci->seek_complete();
         }
 
         sample_count = get_samples(samples);
         if (sample_count < 0)
-        {
-            status = CODEC_ERROR;
             break;
-        }
+ 
         ci->pcmbuf_insert(samples, NULL, sample_count);
         decodedsamples += sample_count;
         if (decodedsamples >= info.DATALENGTH)
@@ -120,11 +120,6 @@ next_track:
         ci->set_elapsed((uint64_t)info.LENGTH * 1000 * decodedsamples / info.DATALENGTH);
     }
 
-done:
     player_stop();
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    return status;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/vorbis.c b/apps/codecs/vorbis.c
index 0a36a37c8b..e02d459262 100644
--- a/apps/codecs/vorbis.c
+++ b/apps/codecs/vorbis.c
@@ -104,14 +104,25 @@ static bool vorbis_set_codec_parameters(OggVorbis_File *vf)
 }
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        if (codec_init())
+            return CODEC_ERROR;
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 24);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     ov_callbacks callbacks;
     OggVorbis_File vf;
     ogg_int32_t **pcm;
 
-    bool initialized = false; /* First init done? */
-    int error;
+    int error = CODEC_ERROR;
     long n;
     int current_section;
     int previous_section;
@@ -120,36 +131,24 @@ enum codec_status codec_main(void)
     ogg_int64_t vf_dataoffsets;
     ogg_uint32_t vf_serialnos;
     ogg_int64_t vf_pcmlengths[2];
-
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 24);
-
-    if (codec_init()) {
-        error = CODEC_ERROR;
-        goto exit;
-    }
+    intptr_t param;
 
 #if defined(CPU_ARM) || defined(CPU_COLDFIRE) || defined(CPU_MIPS)
     if (setjmp(rb_jump_buf) != 0) {
-        /* malloc failed; skip to next track */
-        error = CODEC_ERROR;
+        /* malloc failed; finish with this track */
         goto done;
     }
 #endif
-
-next_track:
-    error = CODEC_OK;
-
     ogg_malloc_init();
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     /* Create a decoder instance */
     callbacks.read_func = read_handler;
     callbacks.seek_func = initial_seek_handler;
     callbacks.tell_func = tell_handler;
     callbacks.close_func = close_handler;
 
+    ci->seek_buffer(0);
+
     /* Open a non-seekable stream */
     error = ov_open_callbacks(ci, &vf, NULL, 0, callbacks);
     
@@ -186,15 +185,13 @@ next_track:
          vf.end = ci->id3->filesize;
          vf.ready_state = OPENED;
          vf.links = 1;
-         initialized = true;
     } else {
          DEBUGF("Vorbis: ov_open failed: %d\n", error);
-         error = CODEC_ERROR;
          goto done;
     }
 
     if (ci->id3->offset) {
-        ci->advance_buffer(ci->id3->offset);
+        ci->seek_buffer(ci->id3->offset);
         ov_raw_seek(&vf, ci->id3->offset);
         ci->set_elapsed(ov_time_tell(&vf));
         ci->set_offset(ov_raw_tell(&vf));
@@ -203,14 +200,17 @@ next_track:
     previous_section = -1;
     eof = 0;
     while (!eof) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track)
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
 
-        if (ci->seek_time) {
-            if (ov_time_seek(&vf, ci->seek_time - 1)) {
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            if (ov_time_seek(&vf, param)) {
                 //ci->logf("ov_time_seek failed");
             }
+
+            ci->set_elapsed(ov_time_tell(&vf));
             ci->seek_complete();
         }
 
@@ -220,7 +220,6 @@ next_track:
         /* Change DSP and buffer settings for this bitstream */
         if (current_section != previous_section) {
             if (!vorbis_set_codec_parameters(&vf)) {
-                error = CODEC_ERROR;
                 goto done;
             } else {
                 previous_section = current_section;
@@ -238,6 +237,7 @@ next_track:
         }
     }
 
+    error = CODEC_OK;
 done:
 #if 0 /* defined(SIMULATOR) */
     {
@@ -249,18 +249,12 @@ done:
 #endif
     ogg_malloc_destroy();
 
-    if (ci->request_next_track()) {
-        if (!initialized)
-            goto next_track;
-        /* Clean things up for the next track */
-        vf.dataoffsets = NULL;
-        vf.offsets = NULL;
-        vf.serialnos = NULL;
-        vf.pcmlengths = NULL;
-        ov_clear(&vf);
-        goto next_track;
-    }
-        
-exit:
+    /* Clean things up for the next track */
+    vf.dataoffsets = NULL;
+    vf.offsets = NULL;
+    vf.serialnos = NULL;
+    vf.pcmlengths = NULL;
+    ov_clear(&vf);
+
     return error;
 }
diff --git a/apps/codecs/vox.c b/apps/codecs/vox.c
index c7f39342c3..bf274c6917 100644
--- a/apps/codecs/vox.c
+++ b/apps/codecs/vox.c
@@ -44,9 +44,19 @@ static uint8_t *read_buffer(size_t *realsize)
 }
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, PCM_OUTPUT_DEPTH-1);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
-    int status;
     uint32_t decodedsamples;
     size_t n;
     int bufcount;
@@ -54,26 +64,18 @@ enum codec_status codec_main(void)
     uint8_t *voxbuf;
     off_t firstblockposn = 0;     /* position of the first block in file */
     const struct pcm_codec *codec;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, PCM_OUTPUT_DEPTH-1);
-  
-next_track:
-    status = CODEC_OK;
+    intptr_t param;
 
     if (codec_init()) {
         DEBUGF("codec_init() error\n");
-        status = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     codec_set_replaygain(ci->id3);
 
     /* Need to save offset for later use (cleared indirectly by advance_buffer) */
     bytesdone = ci->id3->offset;
+    ci->seek_buffer(0);
 
     ci->memset(&format, 0, sizeof(struct pcm_format));
 
@@ -96,20 +98,16 @@ next_track:
     if (!codec)
     {
         DEBUGF("CODEC_ERROR: dialogic oki adpcm codec does not load.\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
-    if (!codec->set_format(&format))
-    {
-        status = CODEC_ERROR;
-        goto done;
+    if (!codec->set_format(&format)) {
+        return CODEC_ERROR;
     }
 
     if (format.numbytes == 0) {
         DEBUGF("CODEC_ERROR: data size is 0\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* check chunksize */
@@ -118,8 +116,7 @@ next_track:
     if (format.chunksize == 0)
     {
         DEBUGF("CODEC_ERROR: chunksize is 0\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
@@ -131,14 +128,14 @@ next_track:
         struct pcm_pos *newpos = codec->get_seek_pos(bytesdone - firstblockposn,
                                                      PCM_SEEK_POS, &read_buffer);
 
-        if (newpos->pos > format.numbytes)
-            goto done;
+        if (newpos->pos > format.numbytes) {
+            return CODEC_OK;
+        }
         if (ci->seek_buffer(firstblockposn + newpos->pos))
         {
             bytesdone      = newpos->pos;
             decodedsamples = newpos->samples;
         }
-        ci->seek_complete();
     } else {
         /* already where we need to be */
         bytesdone = 0;
@@ -148,22 +145,29 @@ next_track:
     endofstream = 0;
 
     while (!endofstream) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
-        }
 
-        if (ci->seek_time) {
-            struct pcm_pos *newpos = codec->get_seek_pos(ci->seek_time, PCM_SEEK_TIME,
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            struct pcm_pos *newpos = codec->get_seek_pos(param, PCM_SEEK_TIME,
                                                          &read_buffer);
 
             if (newpos->pos > format.numbytes)
+            {
+                ci->set_elapsed(ci->id3->length);
+                ci->seek_complete();
                 break;
+            }
+
             if (ci->seek_buffer(firstblockposn + newpos->pos))
             {
                 bytesdone      = newpos->pos;
                 decodedsamples = newpos->samples;
             }
+
+            ci->set_elapsed(decodedsamples*1000LL/ci->id3->frequency);
             ci->seek_complete();
         }
 
@@ -175,11 +179,10 @@ next_track:
             endofstream = 1;
         }
 
-        status = codec->decode(voxbuf, n, samples, &bufcount);
-        if (status == CODEC_ERROR)
+        if (codec->decode(voxbuf, n, samples, &bufcount) == CODEC_ERROR)
         {
             DEBUGF("codec error\n");
-            goto done;
+            return CODEC_ERROR;
         }
 
         ci->pcmbuf_insert(samples, NULL, bufcount);
@@ -192,10 +195,5 @@ next_track:
         ci->set_elapsed(decodedsamples*1000LL/ci->id3->frequency);
     }
 
-done:
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    return status;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/wav.c b/apps/codecs/wav.c
index e179470f27..42bcc7081f 100644
--- a/apps/codecs/wav.c
+++ b/apps/codecs/wav.c
@@ -151,9 +151,19 @@ static uint8_t *read_buffer(size_t *realsize)
 }
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, PCM_OUTPUT_DEPTH-1);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
-    int status;
     uint32_t decodedsamples;
     size_t n;
     int bufcount;
@@ -163,38 +173,28 @@ enum codec_status codec_main(void)
     off_t firstblockposn;     /* position of the first block in file */
     const struct pcm_codec *codec;
     uint32_t size;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, PCM_OUTPUT_DEPTH-1);
-  
-next_track:
-    status = CODEC_OK;
+    intptr_t param;
 
     if (codec_init()) {
         DEBUGF("codec_init() error\n");
-        status = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     codec_set_replaygain(ci->id3);
     
     /* Need to save offset for later use (cleared indirectly by advance_buffer) */
     bytesdone = ci->id3->offset;
 
     /* get RIFF chunk header */
+    ci->seek_buffer(0);
     buf = ci->request_buffer(&n, 12);
     if (n < 12) {
         DEBUGF("request_buffer error\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
     if ((memcmp(buf, "RIFF", 4) != 0) || (memcmp(&buf[8], "WAVE", 4) != 0)) {
         DEBUGF("CODEC_ERROR: missing riff header\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* advance to first WAVE chunk */
@@ -215,8 +215,7 @@ next_track:
         if (n < 8) {
             DEBUGF("data chunk request_buffer error\n");
             /* no more chunks, 'data' chunk must not have been found */
-            status = CODEC_ERROR;
-            goto done;
+            return CODEC_ERROR;
         }
 
         /* chunkSize */
@@ -225,8 +224,7 @@ next_track:
             if (size < 16) {
                 DEBUGF("CODEC_ERROR: 'fmt ' chunk size=%lu < 16\n",
                        (unsigned long)size);
-                status = CODEC_ERROR;
-                goto done;
+                return CODEC_ERROR;
             }
             /* wFormatTag */
             format.formattag=buf[8]|(buf[9]<<8);
@@ -256,8 +254,7 @@ next_track:
                         if (format.size < 22) {
                             DEBUGF("CODEC_ERROR: WAVE_FORMAT_EXTENSIBLE is "
                                    "missing extension\n");
-                            status = CODEC_ERROR;
-                            goto done;
+                            return CODEC_ERROR;
                         }
                         /* wValidBitsPerSample */
                         format.bitspersample = buf[26]|(buf[27]<<8);
@@ -273,8 +270,7 @@ next_track:
             {
                 if (!set_msadpcm_coeffs(buf))
                 {
-                    status = CODEC_ERROR;
-                    goto done;
+                    return CODEC_ERROR;
                 }
             }
 
@@ -284,8 +280,7 @@ next_track:
             {
                 DEBUGF("CODEC_ERROR: unsupported wave format 0x%x\n", 
                     (unsigned int) format.formattag);
-                status = CODEC_ERROR;
-                goto done;
+                return CODEC_ERROR;
             }
 
             /* riff 8bit linear pcm is unsigned */
@@ -295,8 +290,7 @@ next_track:
             /* set format, parse codec specific tag, check format, and calculate chunk size */
             if (!codec->set_format(&format))
             {
-                status = CODEC_ERROR;
-                goto done;
+                return CODEC_ERROR;
             }
         } else if (memcmp(buf, "data", 4) == 0) {
             format.numbytes = size;
@@ -324,31 +318,26 @@ next_track:
     if (!codec)
     {
         DEBUGF("CODEC_ERROR: 'fmt ' chunk not found\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* common format check */
     if (format.channels == 0) {
         DEBUGF("CODEC_ERROR: 'fmt ' chunk not found or 0-channels file\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
     if (format.samplesperblock == 0) {
         DEBUGF("CODEC_ERROR: 'fmt ' chunk not found or 0-wSamplesPerBlock file\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
     if (format.blockalign == 0)
     {
         DEBUGF("CODEC_ERROR: 'fmt ' chunk not found or 0-blockalign file\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
     if (format.numbytes == 0) {
         DEBUGF("CODEC_ERROR: 'data' chunk not found or has zero-length\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* check chunksize */
@@ -358,8 +347,7 @@ next_track:
     if (format.chunksize == 0)
     {
         DEBUGF("CODEC_ERROR: chunksize is 0\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
@@ -369,8 +357,7 @@ next_track:
         ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
     } else {
         DEBUGF("CODEC_ERROR: more than 2 channels\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* make sure we're at the correct offset */
@@ -380,13 +367,12 @@ next_track:
                                                      PCM_SEEK_POS, &read_buffer);
 
         if (newpos->pos > format.numbytes)
-            goto done;
+            return CODEC_OK;
         if (ci->seek_buffer(firstblockposn + newpos->pos))
         {
             bytesdone      = newpos->pos;
             decodedsamples = newpos->samples;
         }
-        ci->seek_complete();
     } else {
         /* already where we need to be */
         bytesdone = 0;
@@ -396,22 +382,28 @@ next_track:
     endofstream = 0;
 
     while (!endofstream) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
-        }
 
-        if (ci->seek_time) {
-            struct pcm_pos *newpos = codec->get_seek_pos(ci->seek_time, PCM_SEEK_TIME,
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            struct pcm_pos *newpos = codec->get_seek_pos(param, PCM_SEEK_TIME,
                                                          &read_buffer);
-
             if (newpos->pos > format.numbytes)
+            {
+                ci->set_elapsed(ci->id3->length);
+                ci->seek_complete();
                 break;
+            }
+
             if (ci->seek_buffer(firstblockposn + newpos->pos))
             {
                 bytesdone      = newpos->pos;
                 decodedsamples = newpos->samples;
             }
+
+            ci->set_elapsed(decodedsamples*1000LL/ci->id3->frequency);
             ci->seek_complete();
         }
 
@@ -423,11 +415,10 @@ next_track:
             endofstream = 1;
         }
 
-        status = codec->decode(wavbuf, n, samples, &bufcount);
-        if (status == CODEC_ERROR)
+        if (codec->decode(wavbuf, n, samples, &bufcount) == CODEC_ERROR)
         {
             DEBUGF("codec error\n");
-            goto done;
+            return CODEC_ERROR;
         }
 
         ci->pcmbuf_insert(samples, NULL, bufcount);
@@ -440,10 +431,5 @@ next_track:
         ci->set_elapsed(decodedsamples*1000LL/ci->id3->frequency);
     }
 
-done:
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    return status;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/wav64.c b/apps/codecs/wav64.c
index 9dbdab8368..c763e6f7f0 100644
--- a/apps/codecs/wav64.c
+++ b/apps/codecs/wav64.c
@@ -159,9 +159,19 @@ static uint8_t *read_buffer(size_t *realsize)
 }
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, PCM_OUTPUT_DEPTH-1);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
-    int status;
     uint32_t decodedsamples;
     size_t n;
     int bufcount;
@@ -171,39 +181,29 @@ enum codec_status codec_main(void)
     off_t firstblockposn;     /* position of the first block in file */
     const struct pcm_codec *codec;
     uint64_t size;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, PCM_OUTPUT_DEPTH-1);
-  
-next_track:
-    status = CODEC_OK;
+    intptr_t param;
 
     if (codec_init()) {
         DEBUGF("codec_init() error\n");
-        status = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     codec_set_replaygain(ci->id3);
     
     /* Need to save offset for later use (cleared indirectly by advance_buffer) */
     bytesdone = ci->id3->offset;
 
     /* get RIFF chunk header */
+    ci->seek_buffer(0);
     buf = ci->request_buffer(&n, 40);
     if (n < 40) {
         DEBUGF("request_buffer error\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
     if ((memcmp(buf   , WAVE64_GUID_RIFF, 16) != 0) ||
         (memcmp(buf+24, WAVE64_GUID_WAVE, 16) != 0))
     {
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* advance to first WAVE chunk */
@@ -224,8 +224,7 @@ next_track:
         if (n < 8) {
             DEBUGF("data chunk request_buffer error\n");
             /* no more chunks, 'data' chunk must not have been found */
-            status = CODEC_ERROR;
-            goto done;
+            return CODEC_ERROR;
         }
 
         /* chunkSize */
@@ -233,8 +232,7 @@ next_track:
         if (memcmp(buf, WAVE64_GUID_FMT, 16) == 0) {
             if (size < 16) {
                 DEBUGF("CODEC_ERROR: 'fmt ' chunk size=%d < 16\n", (int)size);
-                status = CODEC_ERROR;
-                goto done;
+                return CODEC_ERROR;
             }
             /* wFormatTag */
             format.formattag=buf[24]|(buf[25]<<8);
@@ -263,8 +261,7 @@ next_track:
                         if (format.size < 22) {
                             DEBUGF("CODEC_ERROR: WAVE_FORMAT_EXTENSIBLE is "
                                    "missing extension\n");
-                            status = CODEC_ERROR;
-                            goto done;
+                            return CODEC_ERROR;
                         }
                         /* wValidBitsPerSample */
                         format.bitspersample = buf[42]|(buf[43]<<8);
@@ -279,10 +276,7 @@ next_track:
             if (format.formattag == WAVE_FORMAT_ADPCM)
             {
                 if (!set_msadpcm_coeffs(buf))
-                {
-                    status = CODEC_ERROR;
-                    goto done;
-                }
+                    return CODEC_ERROR;
             }
 
             /* get codec */
@@ -291,8 +285,7 @@ next_track:
             {
                 DEBUGF("CODEC_ERROR: unsupported wave format 0x%x\n", 
                     (unsigned int) format.formattag);
-                status = CODEC_ERROR;
-                goto done;
+                return CODEC_ERROR;
             }
 
             /* riff 8bit linear pcm is unsigned */
@@ -301,10 +294,7 @@ next_track:
 
             /* check format, and calculate chunk size */
             if (!codec->set_format(&format))
-            {
-                status = CODEC_ERROR;
-                goto done;
-            }
+                return CODEC_ERROR;
         } else if (memcmp(buf, WAVE64_GUID_DATA, 16) == 0) {
             format.numbytes = size;
             /* advance to start of data */
@@ -330,31 +320,26 @@ next_track:
     if (!codec)
     {
         DEBUGF("CODEC_ERROR: 'fmt ' chunk not found\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* common format check */
     if (format.channels == 0) {
         DEBUGF("CODEC_ERROR: 'fmt ' chunk not found or 0-channels file\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
     if (format.samplesperblock == 0) {
         DEBUGF("CODEC_ERROR: 'fmt ' chunk not found or 0-wSamplesPerBlock file\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
     if (format.blockalign == 0)
     {
         DEBUGF("CODEC_ERROR: 'fmt ' chunk not found or 0-blockalign file\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
     if (format.numbytes == 0) {
         DEBUGF("CODEC_ERROR: 'data' chunk not found or has zero-length\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* check chunksize */
@@ -364,8 +349,7 @@ next_track:
     if (format.chunksize == 0)
     {
         DEBUGF("CODEC_ERROR: chunksize is 0\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
@@ -375,8 +359,7 @@ next_track:
         ci->configure(DSP_SET_STEREO_MODE, STEREO_MONO);
     } else {
         DEBUGF("CODEC_ERROR: more than 2 channels\n");
-        status = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* make sure we're at the correct offset */
@@ -385,14 +368,14 @@ next_track:
         struct pcm_pos *newpos = codec->get_seek_pos(bytesdone - firstblockposn,
                                                      PCM_SEEK_POS, &read_buffer);
 
-        if (newpos->pos > format.numbytes)
-            goto done;
+        if (newpos->pos > format.numbytes) {
+            return CODEC_OK;
+        }
         if (ci->seek_buffer(firstblockposn + newpos->pos))
         {
             bytesdone      = newpos->pos;
             decodedsamples = newpos->samples;
         }
-        ci->seek_complete();
     } else {
         /* already where we need to be */
         bytesdone = 0;
@@ -402,22 +385,29 @@ next_track:
     endofstream = 0;
 
     while (!endofstream) {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
             break;
-        }
 
-        if (ci->seek_time) {
-            struct pcm_pos *newpos = codec->get_seek_pos(ci->seek_time, PCM_SEEK_TIME,
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            struct pcm_pos *newpos = codec->get_seek_pos(param, PCM_SEEK_TIME,
                                                          &read_buffer);
 
             if (newpos->pos > format.numbytes)
+            {
+                ci->set_elapsed(ci->id3->length);
+                ci->seek_complete();
                 break;
+            }
+
             if (ci->seek_buffer(firstblockposn + newpos->pos))
             {
                 bytesdone      = newpos->pos;
                 decodedsamples = newpos->samples;
             }
+
+            ci->set_elapsed(decodedsamples*1000LL/ci->id3->frequency);
             ci->seek_complete();
         }
 
@@ -429,11 +419,10 @@ next_track:
             endofstream = 1;
         }
 
-        status = codec->decode(wavbuf, n, samples, &bufcount);
-        if (status == CODEC_ERROR)
+        if (codec->decode(wavbuf, n, samples, &bufcount) == CODEC_ERROR)
         {
             DEBUGF("codec error\n");
-            goto done;
+            return CODEC_ERROR;
         }
 
         ci->pcmbuf_insert(samples, NULL, bufcount);
@@ -445,12 +434,6 @@ next_track:
             endofstream = 1;
         ci->set_elapsed(decodedsamples*1000LL/ci->id3->frequency);
     }
-    status = CODEC_OK;
-
-done:
-    if (ci->request_next_track())
-        goto next_track;
 
-exit:
-    return status;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/wav_enc.c b/apps/codecs/wav_enc.c
index ef1a88ec23..e4afeaf93c 100644
--- a/apps/codecs/wav_enc.c
+++ b/apps/codecs/wav_enc.c
@@ -345,40 +345,42 @@ static bool init_encoder(void)
     return true;
 } /* init_encoder */
 
-/* main codec entry point */
-enum codec_status codec_main(void)
+/* this is the codec entry point */
+enum codec_status codec_main(enum codec_entry_call_reason reason)
 {
-    if (!init_encoder())
-        return CODEC_ERROR;
+    if (reason == CODEC_LOAD) {
+        if (!init_encoder())
+            return CODEC_ERROR;
+    }
+    else if (reason == CODEC_UNLOAD) {
+        /* reset parameters to initial state */
+        ci->enc_set_parameters(NULL);
+    }
 
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
+{
     /* main encoding loop */
-    while(!ci->stop_codec)
+    while(ci->get_command(NULL) != CODEC_ACTION_HALT)
     {
-        uint32_t *src;
+        uint32_t *src = (uint32_t *)ci->enc_get_pcm_data(PCM_CHUNK_SIZE);
+        struct enc_chunk_hdr *chunk;
 
-        while ((src = (uint32_t *)ci->enc_get_pcm_data(PCM_CHUNK_SIZE)) != NULL)
-        {
-            struct enc_chunk_hdr *chunk;
-
-            if (ci->stop_codec)
-                break;
+        if(src == NULL)
+            continue;
 
-            chunk           = ci->enc_get_chunk();
-            chunk->enc_size = enc_size;
-            chunk->num_pcm  = PCM_SAMP_PER_CHUNK;
-            chunk->enc_data = ENC_CHUNK_SKIP_HDR(chunk->enc_data, chunk);
+        chunk           = ci->enc_get_chunk();
+        chunk->enc_size = enc_size;
+        chunk->num_pcm  = PCM_SAMP_PER_CHUNK;
+        chunk->enc_data = ENC_CHUNK_SKIP_HDR(chunk->enc_data, chunk);
 
-            chunk_to_wav_format(src, (uint32_t *)chunk->enc_data);
+        chunk_to_wav_format(src, (uint32_t *)chunk->enc_data);
 
-            ci->enc_finish_chunk();
-            ci->yield();
-        }
-
-        ci->yield();
+        ci->enc_finish_chunk();
     }
 
-    /* reset parameters to initial state */
-    ci->enc_set_parameters(NULL);
-
     return CODEC_OK;
-} /* codec_start */
+}
diff --git a/apps/codecs/wavpack.c b/apps/codecs/wavpack.c
index d27a9fb621..ccb9f41190 100644
--- a/apps/codecs/wavpack.c
+++ b/apps/codecs/wavpack.c
@@ -31,39 +31,39 @@ static int32_t temp_buffer [BUFFER_SIZE] IBSS_ATTR;
 static int32_t read_callback (void *buffer, int32_t bytes)
 {
     int32_t retval = ci->read_filebuf (buffer, bytes);
-    ci->id3->offset = ci->curpos;
+    ci->set_offset(ci->curpos);
     return retval;
 }
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 28);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     WavpackContext *wpc;
     char error [80];
     int bps, nchans, sr_100;
-    int retval;
+    intptr_t param;
 
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 28);
+    if (codec_init())
+        return CODEC_ERROR;
 
-next_track:
-    retval = CODEC_OK;
+    ci->seek_buffer (ci->id3->offset);
 
-    if (codec_init()) {
-        retval = CODEC_ERROR;
-        goto exit;
-    }
-
-    if (codec_wait_taginfo() != 0)
-        goto done;
-        
     /* Create a decoder instance */
     wpc = WavpackOpenFileInput (read_callback, error);
 
-    if (!wpc) {
-        retval = CODEC_ERROR;
-        goto done;
-    }
+    if (!wpc)
+        return CODEC_ERROR;
 
     ci->configure(DSP_SWITCH_FREQUENCY, WavpackGetSampleRate (wpc));
     codec_set_replaygain(ci->id3);
@@ -77,56 +77,48 @@ next_track:
     /* The main decoder loop */
 
     while (1) {
-        int32_t nsamples;  
+        int32_t nsamples;
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
+            break;
 
-        if (ci->seek_time && ci->taginfo_ready && ci->id3->length) {
-            ci->seek_time--;
+        if (action == CODEC_ACTION_SEEK_TIME) {
             int curpos_ms = WavpackGetSampleIndex (wpc) / sr_100 * 10;
             int n, d, skip;
 
-            if (ci->seek_time > curpos_ms) {
-                n = ci->seek_time - curpos_ms;
+            if (param > curpos_ms) {
+                n = param - curpos_ms;
                 d = ci->id3->length - curpos_ms;
                 skip = (int)((int64_t)(ci->filesize - ci->curpos) * n / d);
                 ci->seek_buffer (ci->curpos + skip);
             }
-            else {
-                n = curpos_ms - ci->seek_time;
+            else if (curpos_ms != 0) {
+                n = curpos_ms - param;
                 d = curpos_ms;
                 skip = (int)((int64_t) ci->curpos * n / d);
                 ci->seek_buffer (ci->curpos - skip);
             }
 
             wpc = WavpackOpenFileInput (read_callback, error);
-            ci->seek_complete();
-
             if (!wpc)
+            {
+                ci->seek_complete();
                 break;
+            }
 
             ci->set_elapsed (WavpackGetSampleIndex (wpc) / sr_100 * 10);
-            ci->yield ();
+            ci->seek_complete();
         }
 
         nsamples = WavpackUnpackSamples (wpc, temp_buffer, BUFFER_SIZE / nchans);  
 
-        if (!nsamples || ci->stop_codec || ci->new_track)
-            break;
-
-        ci->yield ();
-
-        if (ci->stop_codec || ci->new_track)
+        if (!nsamples)
             break;
 
         ci->pcmbuf_insert (temp_buffer, NULL, nsamples);
-
         ci->set_elapsed (WavpackGetSampleIndex (wpc) / sr_100 * 10);
-        ci->yield ();
     }
 
-done:
-    if (ci->request_next_track())
-        goto next_track;
-
-exit:
-    return retval;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/wavpack_enc.c b/apps/codecs/wavpack_enc.c
index d908e284be..730cf0734b 100644
--- a/apps/codecs/wavpack_enc.c
+++ b/apps/codecs/wavpack_enc.c
@@ -389,77 +389,79 @@ static bool init_encoder(void)
     return true;
 } /* init_encoder */
 
-enum codec_status codec_main(void)
+/* this is the codec entry point */
+enum codec_status codec_main(enum codec_entry_call_reason reason)
 {
-    /* initialize params and config */
-    if (!init_encoder())
-        return CODEC_ERROR;
+    if (reason == CODEC_LOAD) {
+        /* initialize params and config */
+        if (!init_encoder())
+            return CODEC_ERROR;
+    }
+    else if (reason == CODEC_UNLOAD) {
+        /* reset parameters to initial state */
+        ci->enc_set_parameters(NULL);
+    }
 
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
+{
     /* main encoding loop */
-    while(!ci->stop_codec)
+    while(ci->get_command(NULL) != CODEC_ACTION_HALT)
     {
-        uint8_t *src;
+        uint8_t *src = (uint8_t *)ci->enc_get_pcm_data(PCM_CHUNK_SIZE);
+        struct enc_chunk_hdr *chunk;
+        bool abort_chunk;
+        uint8_t *dst;
+        uint8_t *src_end;
 
-        while ((src = ci->enc_get_pcm_data(PCM_CHUNK_SIZE)) != NULL)
-        {
-            struct enc_chunk_hdr *chunk;
-            bool     abort_chunk;
-            uint8_t *dst;
-            uint8_t *src_end;
-
-            if(ci->stop_codec)
-                break;
-
-            abort_chunk = true;
+        if(src == NULL)
+            continue;
 
-            chunk = ci->enc_get_chunk();
+        chunk = ci->enc_get_chunk();
 
-            /* reset counts and pointer */
-            chunk->enc_size = 0;
-            chunk->num_pcm  = 0;
-            chunk->enc_data = NULL;
+        /* reset counts and pointer */
+        chunk->enc_size = 0;
+        chunk->num_pcm  = 0;
+        chunk->enc_data = NULL;
 
-            dst = ENC_CHUNK_SKIP_HDR(dst, chunk);
+        dst = ENC_CHUNK_SKIP_HDR(dst, chunk);
 
-            WavpackStartBlock(wpc, dst, dst + data_size);
+        WavpackStartBlock(wpc, dst, dst + data_size);
 
-            chunk_to_int32((uint32_t*)src);
-            src      = input_buffer;
-            src_end  = src + input_size;
+        chunk_to_int32((uint32_t*)src);
+        src      = input_buffer;
+        src_end  = src + input_size;
 
-            /* encode chunk in four steps yielding between each */
-            do
+        /* encode chunk in four steps yielding between each */
+        do
+        {
+            abort_chunk = true;
+            if (WavpackPackSamples(wpc, (int32_t *)src,
+                                   PCM_SAMP_PER_CHUNK/4))
             {
-                if (WavpackPackSamples(wpc, (int32_t *)src,
-                                       PCM_SAMP_PER_CHUNK/4))
-                {
-                    chunk->num_pcm += PCM_SAMP_PER_CHUNK/4;
-                    ci->yield();
-                    /* could've been stopped in some way */
-                    abort_chunk = ci->stop_codec ||
-                                  (chunk->flags & CHUNKF_ABORT);
-                }
-
-                src += input_step;
+                chunk->num_pcm += PCM_SAMP_PER_CHUNK/4;
+                ci->yield();
+                /* could've been stopped in some way */
+                abort_chunk = chunk->flags & CHUNKF_ABORT;
             }
-            while (!abort_chunk && src < src_end);
 
-            if (!abort_chunk)
-            {
-                chunk->enc_data = dst;
-                if (chunk->num_pcm < PCM_SAMP_PER_CHUNK)
-                    ci->enc_unget_pcm_data(PCM_CHUNK_SIZE - chunk->num_pcm*4);
-            /* finish the chunk and store chunk size info */
-                chunk->enc_size = WavpackFinishBlock(wpc);
-                ci->enc_finish_chunk();
-            }
+            src += input_step;
         }
+        while (!abort_chunk && src < src_end);
 
-        ci->yield();
+        if (!abort_chunk)
+        {
+            chunk->enc_data = dst;
+            if (chunk->num_pcm < PCM_SAMP_PER_CHUNK)
+                ci->enc_unget_pcm_data(PCM_CHUNK_SIZE - chunk->num_pcm*4);
+            /* finish the chunk and store chunk size info */
+            chunk->enc_size = WavpackFinishBlock(wpc);
+            ci->enc_finish_chunk();
+        }
     }
 
-    /* reset parameters to initial state */
-    ci->enc_set_parameters(NULL);
- 
     return CODEC_OK;
-} /* codec_start */
+}
diff --git a/apps/codecs/wma.c b/apps/codecs/wma.c
index 1b46813444..c327fafb5a 100644
--- a/apps/codecs/wma.c
+++ b/apps/codecs/wma.c
@@ -29,53 +29,52 @@ CODEC_HEADER
 static WMADecodeContext wmadec;
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 29);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     uint32_t elapsedtime;
-    int retval;
     asf_waveformatex_t wfx;
     size_t resume_offset;
     int i;
-    int wmares, res;
+    int wmares;
+    int res = 0;
     uint8_t* audiobuf;
     int audiobufsize;
     int packetlength = 0;
     int errcount = 0;
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 29);
-
-next_track:
-    retval = CODEC_OK;
+    intptr_t param;
 
     /* Proper reset of the decoder context. */
     memset(&wmadec, 0, sizeof(wmadec));
 
-    /* Wait for the metadata to be read */
-    if (codec_wait_taginfo() != 0)
-        goto done;
-
     /* Remember the resume position - when the codec is opened, the
        playback engine will reset it. */
     resume_offset = ci->id3->offset;
 
 restart_track:
-    retval = CODEC_OK;
-
     if (codec_init()) {
         LOGF("WMA: Error initialising codec\n");
-        retval = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
     /* Copy the format metadata we've stored in the id3 TOC field.  This
        saves us from parsing it again here. */
     memcpy(&wfx, ci->id3->toc, sizeof(wfx));
 
+    ci->seek_buffer(ci->id3->first_frame_offset);
     if (wma_decode_init(&wmadec,&wfx) < 0) {
         LOGF("WMA: Unsupported or corrupt file\n");
-        retval = CODEC_ERROR;
-        goto exit;
+        return CODEC_ERROR;
     }
 
     if (resume_offset > ci->id3->first_frame_offset)
@@ -101,34 +100,35 @@ restart_track:
     codec_set_replaygain(ci->id3);
 
     /* The main decoding loop */
-
-    res = 1;
     while (res >= 0)
     {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
-            goto done;
-        }
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
+            break;
 
         /* Deal with any pending seek requests */
-        if (ci->seek_time){
+        if (action == CODEC_ACTION_SEEK_TIME) {
 
-            if (ci->seek_time == 1) {
+            if (param == 0) {
+                ci->set_elapsed(0);
                 ci->seek_complete();
                 goto restart_track; /* Pretend you never saw this... */
             }
 
-            elapsedtime = asf_seek(ci->seek_time, &wfx);
+            elapsedtime = asf_seek(param, &wfx);
             if (elapsedtime < 1){
+                ci->set_elapsed(0);
                 ci->seek_complete();
-                goto next_track;
+                break;
             }
             /*DEBUGF("Seek returned %d\n", (int)elapsedtime);*/
-            ci->set_elapsed(elapsedtime);
 
             /*flush the wma decoder state*/
             wmadec.last_superframe_len = 0;
             wmadec.last_bitoffset = 0;
+
+            ci->set_elapsed(elapsedtime);
             ci->seek_complete();
         }
         errcount = 0;
@@ -140,10 +140,15 @@ new_packet:
              * times. If we succeed, the error counter will be reset.
              */
 
+            if (res == ASF_ERROR_EOF) {
+                /* File ended - not an error */
+                break;
+            }
+
             errcount++;
             DEBUGF("read_packet error %d, errcount %d\n",wmares, errcount);
             if (errcount > 5) {
-                goto done;
+                return CODEC_ERROR;
             } else {
                 ci->advance_buffer(packetlength);
                 goto new_packet;
@@ -163,7 +168,7 @@ new_packet:
                     errcount++;
                     DEBUGF("WMA decode error %d, errcount %d\n",wmares, errcount);
                     if (errcount > 5) {
-                        goto done;
+                        return CODEC_ERROR;
                     } else {
                         ci->advance_buffer(packetlength);
                         goto new_packet;
@@ -173,18 +178,12 @@ new_packet:
                     elapsedtime += (wmares*10)/(wfx.rate/100);
                     ci->set_elapsed(elapsedtime);
                 }
-                ci->yield();
             }
         }
 
         ci->advance_buffer(packetlength);
     }
 
-done:
     /*LOGF("WMA: Decoded %ld samples\n",elapsedtime*wfx.rate/1000);*/
-
-    if (ci->request_next_track())
-        goto next_track;
-exit:
-    return retval;
+    return CODEC_OK;
 }
diff --git a/apps/codecs/wmapro.c b/apps/codecs/wmapro.c
index c02dddeeb3..b6a8e47f25 100644
--- a/apps/codecs/wmapro.c
+++ b/apps/codecs/wmapro.c
@@ -27,11 +27,22 @@ CODEC_HEADER
 
 int32_t *dec[2]; /* pointers to the output buffers in WMAProDecodeCtx in wmaprodec.c */
 
+
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, WMAPRO_DSP_SAMPLE_DEPTH);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     uint32_t elapsedtime;
-    int retval;
     asf_waveformatex_t wfx;     /* Holds the stream properties */
     size_t resume_offset;
     int res;                    /* Return values from asf_read_packet() and decode_packet() */
@@ -42,28 +53,15 @@ enum codec_status codec_main(void)
     int pktcnt = 0;             /* Count of the packets played */
     uint8_t *data;              /* Pointer to decoder input buffer */
     int size;                   /* Size of the input frame to the decoder */
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, WMAPRO_DSP_SAMPLE_DEPTH);
-    
-
-next_track:
-    retval = CODEC_OK;
-
-    /* Wait for the metadata to be read */
-    if (codec_wait_taginfo() != 0)
-        goto done;
+    intptr_t param;
 
     /* Remember the resume position */
     resume_offset = ci->id3->offset;
 
 restart_track:
-    retval = CODEC_OK;
-
     if (codec_init()) {
         LOGF("(WMA PRO) Error: Error initialising codec\n");
-        retval = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* Copy the format metadata we've stored in the id3 TOC field.  This
@@ -77,8 +75,7 @@ restart_track:
     
     if (decode_init(&wfx) < 0) {
         LOGF("(WMA PRO) Error: Unsupported or corrupt file\n");
-        retval = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* Now advance the file position to the first frame */
@@ -91,23 +88,24 @@ restart_track:
 
     while (pktcnt < wfx.numpackets)
     {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
-            goto done;
-        }
-        
-        /* Deal with any pending seek requests */
-        if (ci->seek_time){
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
+            break;
 
-            if (ci->seek_time == 1) {
+        /* Deal with any pending seek requests */
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            if (param == 0) {
+                ci->set_elapsed(0);
                 ci->seek_complete();
                 goto restart_track; /* Pretend you never saw this... */
             }
 
-            elapsedtime = asf_seek(ci->seek_time, &wfx);
+            elapsedtime = asf_seek(param, &wfx);
             if (elapsedtime < 1){
+                ci->set_elapsed(0);
                 ci->seek_complete();
-                goto next_track;
+                break;
             }
 
             ci->set_elapsed(elapsedtime);
@@ -117,8 +115,8 @@ restart_track:
         res = asf_read_packet(&audiobuf, &audiobufsize, &packetlength, &wfx);
 
         if (res < 0) {
-           LOGF("(WMA PRO) Warning: asf_read_packet returned %d", res);
-           goto done;
+            LOGF("(WMA PRO) Warning: asf_read_packet returned %d", res);
+            return CODEC_ERROR;
         } else {
             data = audiobuf;
             size = audiobufsize;
@@ -132,7 +130,7 @@ restart_track:
                 res = decode_packet(&wfx, dec, &outlen, data, size);
                 if(res < 0) {
                     LOGF("(WMA PRO) Error: decode_packet returned %d", res);
-                    goto done;
+                    return CODEC_ERROR;
                 }
                 data += res;
                 size -= res;
@@ -152,10 +150,6 @@ restart_track:
         ci->advance_buffer(packetlength);
     }
 
-done:
-    if (ci->request_next_track())
-        goto next_track;
-    
-    return retval;
+    return CODEC_OK;
 }
 
diff --git a/apps/codecs/wmavoice.c b/apps/codecs/wmavoice.c
index ddf66828f1..64c8cd1692 100644
--- a/apps/codecs/wmavoice.c
+++ b/apps/codecs/wmavoice.c
@@ -52,10 +52,20 @@ static void init_codec_ctx(AVCodecContext *avctx, asf_waveformatex_t *wfx)
 }
 
 /* this is the codec entry point */
-enum codec_status codec_main(void)
+enum codec_status codec_main(enum codec_entry_call_reason reason)
+{
+    if (reason == CODEC_LOAD) {
+        /* Generic codec initialisation */
+        ci->configure(DSP_SET_SAMPLE_DEPTH, 31);
+    }
+
+    return CODEC_OK;
+}
+
+/* this is called for each file to process */
+enum codec_status codec_run(void)
 {
     uint32_t elapsedtime;
-    int retval;
     asf_waveformatex_t wfx;     /* Holds the stream properties */
     size_t resume_offset;
     int res;                    /* Return values from asf_read_packet() and decode_packet() */
@@ -64,27 +74,14 @@ enum codec_status codec_main(void)
     int packetlength = 0;       /* Logical packet size (minus the header size) */          
     int outlen = 0;             /* Number of bytes written to the output buffer */
     int pktcnt = 0;             /* Count of the packets played */
-
-    /* Generic codec initialisation */
-    ci->configure(DSP_SET_SAMPLE_DEPTH, 31);
-    
-
-next_track:
-    retval = CODEC_OK;
-
-    /* Wait for the metadata to be read */
-    if (codec_wait_taginfo() != 0)
-        goto done;
+    intptr_t param;
 
     /* Remember the resume position */
     resume_offset = ci->id3->offset;
 restart_track:
-    retval = CODEC_OK;
-
     if (codec_init()) {
         LOGF("(WMA Voice) Error: Error initialising codec\n");
-        retval = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* Copy the format metadata we've stored in the id3 TOC field.  This
@@ -97,14 +94,15 @@ restart_track:
     ci->configure(DSP_SET_STEREO_MODE, wfx.channels == 1 ?
                   STEREO_MONO : STEREO_INTERLEAVED);
     codec_set_replaygain(ci->id3);
+
+    ci->seek_buffer(0);
     
     /* Initialise the AVCodecContext */
     init_codec_ctx(&avctx, &wfx);
 
     if (wmavoice_decode_init(&avctx) < 0) {
         LOGF("(WMA Voice) Error: Unsupported or corrupt file\n");
-        retval = CODEC_ERROR;
-        goto done;
+        return CODEC_ERROR;
     }
 
     /* Now advance the file position to the first frame */
@@ -117,21 +115,24 @@ restart_track:
 
     while (pktcnt < wfx.numpackets)
     {
-        ci->yield();
-        if (ci->stop_codec || ci->new_track) {
-            goto done;
-        }
-        
+        enum codec_command_action action = ci->get_command(&param);
+
+        if (action == CODEC_ACTION_HALT)
+            break;
+
         /* Deal with any pending seek requests */
-        if (ci->seek_time){
+        if (action == CODEC_ACTION_SEEK_TIME) {
+            ci->set_elapsed(param);
 
-            if (ci->seek_time == 1) {
+            if (param == 0) {
+                ci->set_elapsed(0);
                 ci->seek_complete();
                 goto restart_track; /* Pretend you never saw this... */
             }
 
-            elapsedtime = asf_seek(ci->seek_time, &wfx);
+            elapsedtime = asf_seek(param, &wfx);
             if (elapsedtime < 1){
+                ci->set_elapsed(0);
                 ci->seek_complete();
                 goto next_track;
             }
@@ -145,7 +146,7 @@ new_packet:
 
         if (res < 0) {
             LOGF("(WMA Voice) read_packet error %d\n",res);
-            goto done;
+            return CODEC_ERROR;
         } else {
             avpkt.data = audiobuf;
             avpkt.size = audiobufsize;
@@ -165,8 +166,9 @@ new_packet:
                         ci->advance_buffer(packetlength);
                         goto new_packet;    
                     }
-                    else
-                        goto done;
+                    else {
+                        return CODEC_ERROR;
+                    }
                 }
                 avpkt.data += res;
                 avpkt.size -= res;
@@ -186,10 +188,6 @@ new_packet:
         ci->advance_buffer(packetlength);
     }
 
-done:
-    if (ci->request_next_track())
-        goto next_track;
-    
-    return retval;
+    return CODEC_OK;
 }