RepoMirrors/ffmpeg
1
0
Fork 0
mirror of https://git.ffmpeg.org/ffmpeg.git synced 2024-12-29 02:42:21 +00:00
Code Issues Projects Releases Wiki Activity

Preallocate index entries in mov demuxer, huge speedup

Browse Source 
Originally committed as revision 22363 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Baptiste Coudurier 2010-03-09 00:46:26 +00:00
parent 1307463d52
commit 987e857f63
1 changed files with 61 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

71
libavformat/mov.c
View File

@ -1462,6 +1462,13 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
current_dts -= sc->dts_shift;
if (sc->sample_count >= UINT_MAX / sizeof(*st->index_entries))
return;
st->index_entries = av_malloc(sc->sample_count*sizeof(*st->index_entries));
if (!st->index_entries)
return;
st->index_entries_allocated_size = sc->sample_count*sizeof(*st->index_entries);
for (i = 0; i < sc->chunk_count; i++) {
current_offset = sc->chunk_offsets[i];
if (stsc_index + 1 < sc->stsc_count &&
@ -1488,8 +1495,12 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
sample_size = sc->sample_size > 0 ? sc->sample_size : sc->sample_sizes[current_sample];
if(sc->pseudo_stream_id == -1 ||
sc->stsc_data[stsc_index].id - 1 == sc->pseudo_stream_id) {
av_add_index_entry(st, current_offset, current_dts, sample_size, distance,
keyframe ? AVINDEX_KEYFRAME : 0);
AVIndexEntry *e = &st->index_entries[st->nb_index_entries++];
e->pos = current_offset;
e->timestamp = current_dts;
e->size = sample_size;
e->min_distance = distance;
e->flags = keyframe ? AVINDEX_KEYFRAME : 0;
dprintf(mov->fc, "AVIndex stream %d, sample %d, offset %"PRIx64", dts %"PRId64", "
"size %d, distance %d, keyframe %d\n", st->index, current_sample,
current_offset, current_dts, sample_size, distance, keyframe);
@ -1510,21 +1521,52 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
if (st->duration > 0)
st->codec->bit_rate = stream_size*8*sc->time_scale/st->duration;
} else {
for (i = 0; i < sc->chunk_count; i++) {
unsigned chunk_samples;
unsigned chunk_samples, total = 0;
// compute total chunk count
for (i = 0; i < sc->stsc_count; i++) {
unsigned count, chunk_count;
chunk_samples = sc->stsc_data[i].count;
if (sc->samples_per_frame && chunk_samples % sc->samples_per_frame) {
av_log(mov->fc, AV_LOG_ERROR, "error unaligned chunk\n");
return;
}
if (sc->samples_per_frame >= 160) { // gsm
count = chunk_samples / sc->samples_per_frame;
} else if (sc->samples_per_frame > 1) {
unsigned samples = (1024/sc->samples_per_frame)*sc->samples_per_frame;
count = (chunk_samples+samples-1) / samples;
} else {
count = (chunk_samples+1023) / 1024;
}
if (i < sc->stsc_count - 1)
chunk_count = sc->stsc_data[i+1].first - sc->stsc_data[i].first;
else
chunk_count = sc->chunk_count - (sc->stsc_data[i].first - 1);
total += chunk_count * count;
}
dprintf(mov->fc, "chunk count %d\n", total);
if (total >= UINT_MAX / sizeof(*st->index_entries))
return;
st->index_entries = av_malloc(total*sizeof(*st->index_entries));
if (!st->index_entries)
return;
st->index_entries_allocated_size = total*sizeof(*st->index_entries);
// populate index
for (i = 0; i < sc->chunk_count; i++) {
current_offset = sc->chunk_offsets[i];
if (stsc_index + 1 < sc->stsc_count &&
i + 1 == sc->stsc_data[stsc_index + 1].first)
stsc_index++;
chunk_samples = sc->stsc_data[stsc_index].count;
if (sc->samples_per_frame && chunk_samples % sc->samples_per_frame) {
av_log(mov->fc, AV_LOG_ERROR, "error unaligned chunk\n");
return;
}
while (chunk_samples > 0) {
AVIndexEntry *e;
unsigned size, samples;
if (sc->samples_per_frame >= 160) { // gsm
@ -1541,7 +1583,16 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
}
}
av_add_index_entry(st, current_offset, current_dts, size, 0, AVINDEX_KEYFRAME);
if (st->nb_index_entries >= total) {
av_log(mov->fc, AV_LOG_ERROR, "wrong chunk count %d\n", total);
return;
}
e = &st->index_entries[st->nb_index_entries++];
e->pos = current_offset;
e->timestamp = current_dts;
e->size = size;
e->min_distance = 0;
e->flags = AVINDEX_KEYFRAME;
dprintf(mov->fc, "AVIndex stream %d, chunk %d, offset %"PRIx64", dts %"PRId64", "
"size %d, duration %d\n", st->index, i, current_offset, current_dts,
size, samples);