[FFmpeg-devel] [PATCH 0/1] avformat/demux: Fix accurate probing of durations in mpegts/ps

[Nicolas Gaullier]

ff_read_packet() is more lightweight, but it leads to important issues
when looking for accurate durations.
As a side effect, the code looks also simpler with regular av_read_frame() calls.

1)
Updates in the fate tests do exhibit most of the results.

2)
See also more directly the case of an audio PES containing many frames:

>ffprobe tests/data/lavf/lavf.ts -select_streams a -show_entries stream=duration -of flat
Before patch:
  streams.stream.0.duration="0.757556"
After patch:
  streams.stream.0.duration="1.018778"

3)
Here is an additional (commonplace) sample to demonstrate the benefit for twofields-encoded video:
https://0x0.st/HFbm.ts (say h264-50i_mp2.ts)

>ffprobe h264-50i_mp2.ts -show_entries stream=duration -of flat
Before patch:
  streams.stream.0.duration="2.060000"
  streams.stream.1.duration="1.176000"
After patch:
  streams.stream.0.duration="2.080000"
  streams.stream.1.duration="1.200000"

Nicolas Gaullier (1):
  avformat/demux: Fix accurate probing of durations in mpegts/ps

 libavformat/demux.c                           |  30 +---
 tests/ref/fate/concat-demuxer-simple2-lavf-ts | 170 +++++++++---------
 tests/ref/fate/ts-opus-demux                  |   4 +-
 3 files changed, 93 insertions(+), 111 deletions(-)

-- 
2.30.2