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authorAndree Buschmann <AndreeBuschmann@t-online.de>2011-03-13 19:25:20 +0000
committerAndree Buschmann <AndreeBuschmann@t-online.de>2011-03-13 19:25:20 +0000
commitff1b2b7fab5bbfa9f81173cdb77a34f08231d0d9 (patch)
tree7c719e99a78ff3ef39eba3c16fb6cab0f2537d1c
parent92183d2dd0275ed91a635733cc5f3d85902a9373 (diff)
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Refactor reading of Xing/Info/Vbri tags to prepare for further changes.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29582 a1c6a512-1295-4272-9138-f99709370657
-rw-r--r--apps/mp3data.c299
1 files changed, 141 insertions, 158 deletions
diff --git a/apps/mp3data.c b/apps/mp3data.c
index f5ef122801..35b4608396 100644
--- a/apps/mp3data.c
+++ b/apps/mp3data.c
@@ -349,32 +349,135 @@ unsigned long mem_find_next_frame(int startpos, long *offset, long max_offset,
}
#endif
-int get_mp3file_info(int fd, struct mp3info *info)
+/* Extract information from a 'Xing' or 'Info' header. */
+static void get_xing_info(struct mp3info *info, unsigned char *buf)
{
- unsigned char frame[1800];
- unsigned char *vbrheader;
- unsigned long header;
- long bytecount;
- int num_offsets;
- int i;
- long offset;
- int j;
- long tmp;
+ int i = 8;
+
+ /* Is it a VBR file? */
+ info->is_vbr = !memcmp(buf, "Xing", 4);
- header = find_next_frame(fd, &bytecount, 0x20000, 0);
- /* Quit if we haven't found a valid header within 128K */
+ if (buf[7] & VBR_FRAMES_FLAG) /* Is the frame count there? */
+ {
+ info->frame_count = bytes2int(buf[i], buf[i+1], buf[i+2], buf[i+3]);
+ if (info->frame_count <= ULONG_MAX / info->ft_num)
+ info->file_time = info->frame_count * info->ft_num / info->ft_den;
+ else
+ info->file_time = info->frame_count / info->ft_den * info->ft_num;
+ i += 4;
+ }
+
+ if (buf[7] & VBR_BYTES_FLAG) /* Is byte count there? */
+ {
+ info->byte_count = bytes2int(buf[i], buf[i+1], buf[i+2], buf[i+3]);
+ i += 4;
+ }
+
+ if (info->file_time && info->byte_count)
+ {
+ if (info->byte_count <= (ULONG_MAX/8))
+ info->bitrate = info->byte_count * 8 / info->file_time;
+ else
+ info->bitrate = info->byte_count / (info->file_time >> 3);
+ }
+
+ if (buf[7] & VBR_TOC_FLAG) /* Is table-of-contents there? */
+ {
+ info->has_toc = true;
+ memcpy( info->toc, buf+i, 100 );
+ i += 100;
+ }
+ if (buf[7] & VBR_QUALITY_FLAG)
+ {
+ /* We don't care about this, but need to skip it */
+ i += 4;
+ }
+#if CONFIG_CODEC==SWCODEC
+ i += 21;
+ info->enc_delay = ((int)buf[i ] << 4) | (buf[i+1] >> 4);
+ info->enc_padding = ((int)buf[i+1] << 8) | buf[i+2];
+ /* TODO: This sanity checking is rather silly, seeing as how the LAME
+ header contains a CRC field that can be used to verify integrity. */
+ if (!(info->enc_delay >= 0 && info->enc_delay <= 2880 &&
+ info->enc_padding >= 0 && info->enc_padding <= 2*1152))
+ {
+ /* Invalid data */
+ info->enc_delay = -1;
+ info->enc_padding = -1;
+ }
+#endif
+}
+
+/* Extract information from a 'VBRI' header. */
+static void get_vbri_info(struct mp3info *info, unsigned char *buf)
+{
+ int i, num_offsets, offset = 0;
+
+ info->is_vbr = true; /* Yes, it is a FhG VBR file */
+ info->has_toc = false; /* We don't parse the TOC (yet) */
+
+ info->byte_count = bytes2int(buf[10], buf[11], buf[12], buf[13]);
+ info->frame_count = bytes2int(buf[14], buf[15], buf[16], buf[17]);
+ if (info->frame_count <= ULONG_MAX / info->ft_num)
+ info->file_time = info->frame_count * info->ft_num / info->ft_den;
+ else
+ info->file_time = info->frame_count / info->ft_den * info->ft_num;
+
+ if (info->byte_count <= (ULONG_MAX/8))
+ info->bitrate = info->byte_count * 8 / info->file_time;
+ else
+ info->bitrate = info->byte_count / (info->file_time >> 3);
+
+ /* We don't parse the TOC, since we don't yet know how to (FIXME) */
+ num_offsets = bytes2int(0, 0, buf[18], buf[19]);
+ VDEBUGF("Frame size (%dkpbs): %d bytes (0x%x)\n",
+ info->bitrate, info->frame_size, info->frame_size);
+ VDEBUGF("Frame count: %lx\n", info->frame_count);
+ VDEBUGF("Byte count: %lx\n", info->byte_count);
+ VDEBUGF("Offsets: %d\n", num_offsets);
+ VDEBUGF("Frames/entry: %ld\n",
+ bytes2int(0, 0, buf[24], buf[25]));
+
+ for(i = 0; i < num_offsets; i++)
+ {
+ offset += bytes2int(0, 0, buf[26+i*2], buf[27+i*2]);;
+ VDEBUGF("%03d: %lx\n", i, offset - bytecount,);
+ }
+}
+
+/* Seek to next mpeg header and extract relevant information. */
+static int get_next_header_info(int fd, long *bytecount, struct mp3info *info)
+{
+ unsigned long header = find_next_frame(fd, bytecount, 0x20000, 0);
if(header == 0)
return -1;
+ if(!mp3headerinfo(info, header))
+ return -2;
+
+ return 0;
+}
+
+int get_mp3file_info(int fd, struct mp3info *info)
+{
+ unsigned char frame[1800], *vbrheader;
+ long bytecount;
+ int result;
+
+ /* Initialize info and frame */
memset(info, 0, sizeof(struct mp3info));
memset(frame, 0, sizeof(frame));
+
#if CONFIG_CODEC==SWCODEC
/* These two are needed for proper LAME gapless MP3 playback */
- info->enc_delay = -1;
+ info->enc_delay = -1;
info->enc_padding = -1;
#endif
- if(!mp3headerinfo(info, header))
- return -2;
+
+ /* Get the very first MPEG frame. */
+ result = get_next_header_info(fd, &bytecount, info);
+ if(result)
+ return result;
/* OK, we have found a frame. Let's see if it has a Xing header */
if (info->frame_size-4 >= (int)sizeof(frame))
@@ -386,170 +489,50 @@ int get_mp3file_info(int fd, struct mp3info *info)
if(read(fd, frame, info->frame_size-4) < 0)
return -3;
- /* calculate position of VBR header */
- if ( info->version == MPEG_VERSION1 ) {
+ /* Calculate position of a possible VBR header */
+ if (info->version == MPEG_VERSION1) {
if (info->channel_mode == 3) /* mono */
vbrheader = frame + 17;
else
vbrheader = frame + 32;
- }
- else {
+ } else {
if (info->channel_mode == 3) /* mono */
vbrheader = frame + 9;
else
vbrheader = frame + 17;
}
- if (!memcmp(vbrheader, "Xing", 4)
- || !memcmp(vbrheader, "Info", 4))
+ if (!memcmp(vbrheader, "Xing", 4) || !memcmp(vbrheader, "Info", 4))
{
- int i = 8; /* Where to start parsing info */
-
- /* DEBUGF("Xing/Info header\n"); */
+ VDEBUGF("-- XING header --\n");
- /* Remember where in the file the Xing header is */
-/* Rockbox: not used
- info->vbr_header_pos = lseek(fd, 0, SEEK_CUR) - info->frame_size;
-*/
/* We want to skip the Xing frame when playing the stream */
bytecount += info->frame_size;
- /* Now get the next frame to find out the real info about
- the mp3 stream */
- header = find_next_frame(fd, &tmp, 0x20000, 0);
- if(header == 0)
- return -4;
-
- if(!mp3headerinfo(info, header))
- return -5;
-
- /* Is it a VBR file? */
- info->is_vbr = !memcmp(vbrheader, "Xing", 4);
-/* Rockbox: not used
- info->is_xing_vbr = info->is_vbr;
-*/
-
- if (vbrheader[7] & VBR_FRAMES_FLAG) /* Is the frame count there? */
- {
- info->frame_count = bytes2int(vbrheader[i], vbrheader[i+1],
- vbrheader[i+2], vbrheader[i+3]);
- if (info->frame_count <= ULONG_MAX / info->ft_num)
- info->file_time = info->frame_count * info->ft_num / info->ft_den;
- else
- info->file_time = info->frame_count / info->ft_den * info->ft_num;
- i += 4;
- }
-
- if (vbrheader[7] & VBR_BYTES_FLAG) /* Is byte count there? */
- {
- info->byte_count = bytes2int(vbrheader[i], vbrheader[i+1],
- vbrheader[i+2], vbrheader[i+3]);
- i += 4;
- }
-
- if (info->file_time && info->byte_count)
- {
- if (info->byte_count <= (ULONG_MAX/8))
- info->bitrate = info->byte_count * 8 / info->file_time;
- else
- info->bitrate = info->byte_count / (info->file_time >> 3);
- }
-
- if (vbrheader[7] & VBR_TOC_FLAG) /* Is table-of-contents there? */
- {
- info->has_toc = true;
- memcpy( info->toc, vbrheader+i, 100 );
- i += 100;
- }
- if (vbrheader[7] & VBR_QUALITY_FLAG)
- {
- /* We don't care about this, but need to skip it */
- i += 4;
- }
-#if CONFIG_CODEC==SWCODEC
- i += 21;
- info->enc_delay = ((int)vbrheader[i ] << 4) | (vbrheader[i+1] >> 4);
- info->enc_padding = ((int)vbrheader[i+1] << 8) | vbrheader[i+2];
- /* TODO: This sanity checking is rather silly, seeing as how the LAME
- header contains a CRC field that can be used to verify integrity. */
- if (!(info->enc_delay >= 0 && info->enc_delay <= 2880 &&
- info->enc_padding >= 0 && info->enc_padding <= 2*1152))
- {
- /* Invalid data */
- info->enc_delay = -1;
- info->enc_padding = -1;
- }
-#endif
+ /* Now get the next frame to read the real info about the mp3 stream */
+ result = get_next_header_info(fd, &bytecount, info);
+ if(result)
+ return result;
+
+ get_xing_info(info, vbrheader);
}
-
- if (!memcmp(vbrheader, "VBRI", 4))
+ else if (!memcmp(vbrheader, "VBRI", 4))
{
- VDEBUGF("VBRI header\n");
+ VDEBUGF("-- VBRI header --\n");
/* We want to skip the VBRI frame when playing the stream */
bytecount += info->frame_size;
- /* Now get the next frame to find out the real info about
- the mp3 stream */
- header = find_next_frame(fd, &tmp, 0x20000, 0);
- if(header == 0)
- return -6;
-
- bytecount += tmp;
-
- if(!mp3headerinfo(info, header))
- return -7;
-
- VDEBUGF("%04x: %04x %04x ", 0, (short)(header >> 16),
- (short)(header & 0xffff));
- for(i = 4;i < (int)sizeof(frame)-4;i+=2) {
- if(i % 16 == 0) {
- VDEBUGF("\n%04x: ", i-4);
- }
- VDEBUGF("%04x ", (frame[i-4] << 8) | frame[i-4+1]);
- }
-
- VDEBUGF("\n");
-
- /* Yes, it is a FhG VBR file */
- info->is_vbr = true;
-/* Rockbox: not used
- info->is_vbri_vbr = true;
-*/
- info->has_toc = false; /* We don't parse the TOC (yet) */
-
- info->byte_count = bytes2int(vbrheader[10], vbrheader[11],
- vbrheader[12], vbrheader[13]);
- info->frame_count = bytes2int(vbrheader[14], vbrheader[15],
- vbrheader[16], vbrheader[17]);
- if (info->frame_count <= ULONG_MAX / info->ft_num)
- info->file_time = info->frame_count * info->ft_num / info->ft_den;
- else
- info->file_time = info->frame_count / info->ft_den * info->ft_num;
-
- if (info->byte_count <= (ULONG_MAX/8))
- info->bitrate = info->byte_count * 8 / info->file_time;
- else
- info->bitrate = info->byte_count / (info->file_time >> 3);
-
- /* We don't parse the TOC, since we don't yet know how to (FIXME) */
- num_offsets = bytes2int(0, 0, vbrheader[18], vbrheader[19]);
- VDEBUGF("Frame size (%dkpbs): %d bytes (0x%x)\n",
- info->bitrate, info->frame_size, info->frame_size);
- VDEBUGF("Frame count: %lx\n", info->frame_count);
- VDEBUGF("Byte count: %lx\n", info->byte_count);
- VDEBUGF("Offsets: %d\n", num_offsets);
- VDEBUGF("Frames/entry: %ld\n",
- bytes2int(0, 0, vbrheader[24], vbrheader[25]));
-
- offset = 0;
-
- for(i = 0;i < num_offsets;i++)
- {
- j = bytes2int(0, 0, vbrheader[26+i*2], vbrheader[27+i*2]);
- offset += j;
- VDEBUGF("%03d: %lx (%x)\n", i, offset - bytecount, j);
- }
+ /* Now get the next frame to read the real info about the mp3 stream */
+ result = get_next_header_info(fd, &bytecount, info);
+ if(result)
+ return result;
+
+ get_vbri_info(info, vbrheader);
+ }
+ else
+ {
+ VDEBUGF("-- No VBR header --\n");
}
return bytecount;