summaryrefslogtreecommitdiffstats
path: root/lib/rbcodec/codecs
diff options
context:
space:
mode:
Diffstat (limited to 'lib/rbcodec/codecs')
-rw-r--r--lib/rbcodec/codecs/libm4a/demux.c31
-rw-r--r--lib/rbcodec/codecs/libm4a/m4a.c148
-rw-r--r--lib/rbcodec/codecs/libm4a/m4a.h1
3 files changed, 127 insertions, 53 deletions
diff --git a/lib/rbcodec/codecs/libm4a/demux.c b/lib/rbcodec/codecs/libm4a/demux.c
index 3bf46efec6..e29ecb8339 100644
--- a/lib/rbcodec/codecs/libm4a/demux.c
+++ b/lib/rbcodec/codecs/libm4a/demux.c
@@ -349,6 +349,7 @@ static bool read_chunk_stts(qtmovie_t *qtmovie, size_t chunk_len)
static bool read_chunk_stsz(qtmovie_t *qtmovie, size_t chunk_len)
{
size_t size_remaining = chunk_len - 8;
+ uint32_t numsizes, i;
/* version */
stream_read_uint8(qtmovie->stream);
@@ -369,9 +370,37 @@ static bool read_chunk_stsz(qtmovie_t *qtmovie, size_t chunk_len)
}
size_remaining -= 4;
- qtmovie->res->num_sample_byte_sizes = stream_read_uint32(qtmovie->stream);
+ numsizes = stream_read_uint32(qtmovie->stream);
size_remaining -= 4;
+ /* Because this table can be really large and is only used to improve seek
+ * accuracy, it's optional. In that case the seek code will fall back to a
+ * less accurate seek method. */
+ qtmovie->res->num_sample_byte_sizes = numsizes;
+ if (numsizes * sizeof(uint32_t) < CODEC_SIZE * 1 / 2)
+ qtmovie->res->sample_byte_sizes = malloc(numsizes * sizeof(uint32_t));
+ else
+ qtmovie->res->sample_byte_sizes = NULL;
+
+ if (qtmovie->res->sample_byte_sizes)
+ {
+ for (i = 0; i < numsizes; ++i)
+ {
+ qtmovie->res->sample_byte_sizes[i] =
+ stream_read_uint32(qtmovie->stream);
+ size_remaining -= 4;
+ }
+
+ if (size_remaining)
+ {
+ DEBUGF("extra bytes after stsz\n");
+ }
+ }
+ else
+ {
+ DEBUGF("stsz too large, ignoring it\n");
+ }
+
if (size_remaining)
{
stream_skip(qtmovie->stream, size_remaining);
diff --git a/lib/rbcodec/codecs/libm4a/m4a.c b/lib/rbcodec/codecs/libm4a/m4a.c
index 5fe778ac03..b967e15e7a 100644
--- a/lib/rbcodec/codecs/libm4a/m4a.c
+++ b/lib/rbcodec/codecs/libm4a/m4a.c
@@ -23,6 +23,13 @@
#include <inttypes.h>
#include "m4a.h"
+#undef DEBUGF
+#if defined(DEBUG)
+#define DEBUGF stream->ci->debugf
+#else
+#define DEBUGF(...)
+#endif
+
/* Implementation of the stream.h functions used by libalac */
#define _Swap32(v) do { \
@@ -127,76 +134,113 @@ int m4a_check_sample_offset(demux_res_t *demux_res, uint32_t frame, uint32_t *st
return demux_res->lookup_table[i].offset;
}
-/* Find the exact or preceding frame in lookup_table[]. Return both frame
- * and byte position of this match. */
-static void gather_offset(demux_res_t *demux_res, uint32_t *frame, uint32_t *offset)
-{
- uint32_t i = 0;
- for (i=0; i<demux_res->num_lookup_table; ++i)
- {
- if (demux_res->lookup_table[i].offset == 0)
- break;
- if (demux_res->lookup_table[i].sample > *frame)
- break;
- }
- i = (i>0) ? i-1 : 0; /* We want the last chunk _before_ *frame. */
- *frame = demux_res->lookup_table[i].sample;
- *offset = demux_res->lookup_table[i].offset;
-}
-
/* Seek to desired sound sample location. Return 1 on success (and modify
- * sound_samples_done and current_sample), 0 if failed.
- *
- * Find the sample (=frame) that contains the given sound sample, find a best
- * fit for this sample in the lookup_table[], seek to the byte position. */
+ * sound_samples_done and current_sample), 0 if failed. */
unsigned int m4a_seek(demux_res_t* demux_res, stream_t* stream,
uint32_t sound_sample_loc, uint32_t* sound_samples_done,
int* current_sample)
{
- uint32_t i = 0;
- uint32_t tmp_var, tmp_cnt, tmp_dur;
- uint32_t new_sample = 0; /* Holds the amount of chunks/frames. */
- uint32_t new_sound_sample = 0; /* Sums up total amount of samples. */
- uint32_t new_pos; /* Holds the desired chunk/frame index. */
-
- /* First check we have the appropriate metadata - we should always
- * have it.
- */
+ uint32_t i, sample_i, sound_sample_i;
+ uint32_t time, time_cnt, time_dur;
+ uint32_t chunk, chunk_first_sample;
+ uint32_t offset;
+ time_to_sample_t *tts_tab = demux_res->time_to_sample;
+ sample_offset_t *tco_tab = demux_res->lookup_table;
+ uint32_t *tsz_tab = demux_res->sample_byte_sizes;
+
+ /* First check we have the required metadata - we should always have it. */
if (!demux_res->num_time_to_samples || !demux_res->num_sample_byte_sizes)
- {
- return 0;
+ {
+ return 0;
}
- /* Find the destination block from time_to_sample array */
- time_to_sample_t *tab = demux_res->time_to_sample;
- while (i < demux_res->num_time_to_samples)
+ /* The 'sound_sample_loc' we have is PCM-based and not directly usable.
+ * We need to convert it to an MP4 sample number 'sample_i' first. */
+ sample_i = sound_sample_i = 0;
+ for (time = 0; time < demux_res->num_time_to_samples; ++time)
{
- tmp_cnt = tab[i].sample_count;
- tmp_dur = tab[i].sample_duration;
- tmp_var = tmp_cnt * tmp_dur;
- if (sound_sample_loc <= new_sound_sample + tmp_var)
+ time_cnt = tts_tab[time].sample_count;
+ time_dur = tts_tab[time].sample_duration;
+ uint32_t time_var = time_cnt * time_dur;
+
+ if (sound_sample_loc < sound_sample_i + time_var)
{
- tmp_var = (sound_sample_loc - new_sound_sample);
- new_sample += tmp_var / tmp_dur;
- new_sound_sample += tmp_var;
+ time_var = sound_sample_loc - sound_sample_i;
+ sample_i += time_var / time_dur;
break;
}
- new_sample += tmp_cnt;
- new_sound_sample += tmp_var;
- ++i;
+
+ sample_i += time_cnt;
+ sound_sample_i += time_var;
+ }
+
+ /* Find the chunk after 'sample_i'. */
+ for (chunk = 1; chunk < demux_res->num_lookup_table; ++chunk)
+ {
+ if (tco_tab[chunk].offset == 0)
+ break;
+ if (tco_tab[chunk].sample > sample_i)
+ break;
}
- /* We know the new sample (=frame), now calculate the file position. */
- gather_offset(demux_res, &new_sample, &new_pos);
+ /* The preceding chunk is the one that contains 'sample_i'. */
+ chunk--;
+ chunk_first_sample = tco_tab[chunk].sample;
+ offset = tco_tab[chunk].offset;
- /* We know the new file position, so let's try to seek to it */
- if (stream->ci->seek_buffer(new_pos))
+ /* Compute the PCM sample number of the chunk's first sample
+ * to get an accurate base for sound_sample_i. */
+ i = sound_sample_i = 0;
+ for (time = 0; time < demux_res->num_time_to_samples; ++time)
{
- *sound_samples_done = new_sound_sample;
- *current_sample = new_sample;
+ time_cnt = tts_tab[time].sample_count;
+ time_dur = tts_tab[time].sample_duration;
+
+ if (chunk_first_sample < i + time_cnt)
+ {
+ sound_sample_i += (chunk_first_sample - i) * time_dur;
+ break;
+ }
+
+ i += time_cnt;
+ sound_sample_i += time_cnt * time_dur;
+ }
+
+ DEBUGF("seek chunk=%lu, sample=%lu, soundsample=%lu, offset=%lu\n",
+ (unsigned long)chunk, (unsigned long)chunk_first_sample,
+ (unsigned long)sound_sample_i, (unsigned long)offset);
+
+ if (tsz_tab) {
+ /* We have a sample-to-bytes table available so we can do accurate
+ * seeking. Move one sample at a time and update the file offset and
+ * PCM sample offset as we go. */
+ for (i = chunk_first_sample;
+ i < sample_i && i < demux_res->num_sample_byte_sizes; ++i)
+ {
+ /* this could be unnecessary */
+ if (time_cnt == 0 && ++time < demux_res->num_time_to_samples)
+ {
+ time_cnt = tts_tab[time].sample_count;
+ time_dur = tts_tab[time].sample_duration;
+ }
+
+ offset += tsz_tab[i];
+ sound_sample_i += time_dur;
+ time_cnt--;
+ }
+ } else {
+ /* No sample-to-bytes table available so we can only seek to the
+ * start of a chunk, which is often much lower resolution. */
+ sample_i = chunk_first_sample;
+ }
+
+ if (stream->ci->seek_buffer(offset))
+ {
+ *sound_samples_done = sound_sample_i;
+ *current_sample = sample_i;
return 1;
}
-
+
return 0;
}
diff --git a/lib/rbcodec/codecs/libm4a/m4a.h b/lib/rbcodec/codecs/libm4a/m4a.h
index aa8e768045..81b10c3a27 100644
--- a/lib/rbcodec/codecs/libm4a/m4a.h
+++ b/lib/rbcodec/codecs/libm4a/m4a.h
@@ -80,6 +80,7 @@ typedef struct
time_to_sample_t *time_to_sample;
uint32_t num_time_to_samples;
+ uint32_t *sample_byte_sizes;
uint32_t num_sample_byte_sizes;
uint32_t codecdata_len;