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| author | Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com> | 2015-05-27 23:57:50 +0200 |
|---|---|---|
| committer | Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com> | 2015-05-29 19:35:58 +0200 |
| commit | 153639cb9cfacfdb094f0fa42012fa5c547246f4 (patch) | |
| tree | bcf40200df7925b1337ab107927248d602ae6e8f | |
| parent | 403940de241e8f15ec9eae3e69c6c2f423bafcf5 (diff) | |
| download | ffmpeg-153639cb9cfacfdb094f0fa42012fa5c547246f4.tar.gz | |
mov: fix DTS calculation for samples with negative stts duration
A negative sample duration is invalid according to the spec, but there
are samples that use it for the DTS calculation, e.g.:
http://files.1f0.de/samples/mp4-negative-stts-problem.mp4
These currently get out of A/V sync.
Also change the logging type to AV_LOG_WARNING, because decoding the
sample can continue.
Reviewed-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
| -rw-r--r-- | libavformat/mov.c | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/libavformat/mov.c b/libavformat/mov.c index 60729343dd..5cea5fdde2 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -2234,12 +2234,6 @@ static int mov_read_stts(MOVContext *c, AVIOContext *pb, MOVAtom atom) sample_count=avio_rb32(pb); sample_duration = avio_rb32(pb); - /* sample_duration < 0 is invalid based on the spec */ - if (sample_duration < 0) { - av_log(c->fc, AV_LOG_ERROR, "Invalid SampleDelta %d in STTS, at %d st:%d\n", - sample_duration, i, c->fc->nb_streams-1); - sample_duration = 1; - } if (sample_count < 0) { av_log(c->fc, AV_LOG_ERROR, "Invalid sample_count=%d\n", sample_count); return AVERROR_INVALIDDATA; @@ -2439,10 +2433,13 @@ static void mov_build_index(MOVContext *mov, AVStream *st) unsigned int distance = 0; unsigned int rap_group_index = 0; unsigned int rap_group_sample = 0; + int64_t last_dts = 0; + int64_t dts_correction = 0; int rap_group_present = sc->rap_group_count && sc->rap_group; int key_off = (sc->keyframe_count && sc->keyframes[0] > 0) || (sc->stps_count && sc->stps_data[0] > 0); current_dts -= sc->dts_shift; + last_dts = current_dts; if (!sc->sample_count || st->nb_index_entries) return; @@ -2522,7 +2519,27 @@ static void mov_build_index(MOVContext *mov, AVStream *st) current_offset += sample_size; stream_size += sample_size; + + /* A negative sample duration is invalid based on the spec, + * but some samples need it to correct the DTS. */ + if (sc->stts_data[stts_index].duration < 0) { + av_log(mov->fc, AV_LOG_WARNING, + "Invalid SampleDelta %d in STTS, at %d st:%d\n", + sc->stts_data[stts_index].duration, stts_index, + st->index); + dts_correction += sc->stts_data[stts_index].duration - 1; + sc->stts_data[stts_index].duration = 1; + } current_dts += sc->stts_data[stts_index].duration; + if (!dts_correction || current_dts + dts_correction > last_dts) { + current_dts += dts_correction; + dts_correction = 0; + } else { + /* Avoid creating non-monotonous DTS */ + dts_correction += current_dts - last_dts - 1; + current_dts = last_dts + 1; + } + last_dts = current_dts; distance++; stts_sample++; current_sample++; |