Rockbox open source high quality audio player as a Music Player Daemon
mpris
rockbox
mpd
libadwaita
audio
rust
zig
deno
Codecs: mp4: Accurate seek in large files with small lookup_table
Read sample_byte_sizes table on demand when it can't be cached
Change-Id: I2191be63ceebfd8b16e1e973e13c5b51986b6564
+25
-6
+10
-1
lib/rbcodec/codecs/libm4a/demux.c
+10
-1
lib/rbcodec/codecs/libm4a/demux.c
···
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}
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else
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{
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-
DEBUGF("stsz too large, ignoring it\n");
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+
qtmovie->res->sample_byte_sizes_offset = stream_tell(qtmovie->stream);
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+
DEBUGF("stsz too large: %u, save sample_byte_sizes_offset\n", numsizes);
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}
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if (size_remaining)
···
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{
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DEBUGF("stco too large to allocate lookup_table[]\n");
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return false;
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+
}
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+
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+
// Reading sample_byte_sizes data on seek can lead to additional re-buffering.
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+
// So skip it if we have good enough seek accuracy via lookup_table (3000 ms)
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+
if (qtmovie->res->sample_byte_sizes_offset && ci->id3->length / fit_numentries <= 3000)
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+
{
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+
qtmovie->res->sample_byte_sizes_offset = 0;
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+
DEBUGF("lookup_table seek accuracy %ld ms, ignoring sample_byte_sizes_offset \n", ci->id3->length / fit_numentries);
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}
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/* Build up lookup table. The lookup table contains the sample index and
+14
-5
lib/rbcodec/codecs/libm4a/m4a.c
+14
-5
lib/rbcodec/codecs/libm4a/m4a.c
···
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sound_sample_i += time_cnt * time_dur;
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}
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-
DEBUGF("seek chunk=%lu, sample=%lu, soundsample=%lu, offset=%lu\n",
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-
(unsigned long)chunk, (unsigned long)chunk_first_sample,
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-
sound_sample_i, (unsigned long)offset);
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+
if (demux_res->sample_byte_sizes_offset)
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+
{
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+
stream->ci->seek_buffer(demux_res->sample_byte_sizes_offset + chunk_first_sample * 4);
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+
}
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-
if (tsz_tab) {
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+
if (tsz_tab || demux_res->sample_byte_sizes_offset)
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+
{
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/* We have a sample-to-bytes table available so we can do accurate
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* seeking. Move one sample at a time and update the file offset and
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* PCM sample offset as we go. */
···
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time_dur = tts_tab[time].sample_duration;
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}
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-
offset += tsz_tab[i];
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+
offset += tsz_tab ? tsz_tab[i] : stream_read_uint32(stream);
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sound_sample_i += time_dur;
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time_cnt--;
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}
···
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* start of a chunk, which is often much lower resolution. */
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sample_i = chunk_first_sample;
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}
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+
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+
DEBUGF("seek chunk=%lu, chunk_first_sample=%lu, sample_i=%u, soundsample=%lu, offset=%lu\n",
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+
(unsigned long)chunk,
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+
(unsigned long)chunk_first_sample,
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+
sample_i,
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+
(unsigned long)sound_sample_i,
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+
(unsigned long)offset);
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if (stream->ci->seek_buffer(offset))
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{