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Codecs: mp4: Accurate seek in large files with small lookup_table

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Read sample_byte_sizes table on demand when it can't be cached

Change-Id: I2191be63ceebfd8b16e1e973e13c5b51986b6564
This commit is contained in:
roman.artiukhin 2023-09-05 00:45:32 +03:00
parent e01055a287
commit 57409f52d5
3 changed files with 25 additions and 6 deletions
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19
lib/rbcodec/codecs/libm4a/m4a.c
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@ -211,11 +211,13 @@ unsigned int m4a_seek(demux_res_t* demux_res, stream_t* stream,
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,
sound_sample_i, (unsigned long)offset);
if (demux_res->sample_byte_sizes_offset)
{
stream->ci->seek_buffer(demux_res->sample_byte_sizes_offset + chunk_first_sample * 4);
}
if (tsz_tab) {
if (tsz_tab || demux_res->sample_byte_sizes_offset)
{
/* 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. */
@ -229,7 +231,7 @@ unsigned int m4a_seek(demux_res_t* demux_res, stream_t* stream,
time_dur = tts_tab[time].sample_duration;
}
offset += tsz_tab[i];
offset += tsz_tab ? tsz_tab[i] : stream_read_uint32(stream);
sound_sample_i += time_dur;
time_cnt--;
}
@ -239,6 +241,13 @@ unsigned int m4a_seek(demux_res_t* demux_res, stream_t* stream,
sample_i = chunk_first_sample;
}
DEBUGF("seek chunk=%lu, chunk_first_sample=%lu, sample_i=%u, soundsample=%lu, offset=%lu\n",
(unsigned long)chunk,
(unsigned long)chunk_first_sample,
sample_i,
(unsigned long)sound_sample_i,
(unsigned long)offset);
if (stream->ci->seek_buffer(offset))
{
*sound_samples_done = sound_sample_i;