[FFmpeg-trac] #8009(avformat:new): hls demuxer does not handle pid changes after EXT-X-DISCONTINUITY

[FFmpeg]

#8009: hls demuxer does not handle pid changes after EXT-X-DISCONTINUITY
------------------------------------+------------------------------------
             Reporter:  Aman        |                    Owner:  (none)
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  avformat
              Version:  git-master  |               Resolution:
             Keywords:  hls         |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
------------------------------------+------------------------------------
Comment (by Vraz):

 > Before the discontinuity, 0x101 is a video PID but afterwards it is an
 audio PID.
 ffmpeg does not detect this PMT change, and feeds audio packets into the
 video decoder and vice versa.

 Enabled merge_pmt_versions within hls.c, and instead of preventing extra
 streams, it duplicates the above issue. The problem is
 mpegts.c::find_matching_stream() is super simplistic and unclear if it
 ever does anything useful. It fails to verify the stream-type prior to
 merging thus often resulting in damaged streams.

 Changed find_matching_stream() to match on program_num and stream_type and
 that seemed to resolve it. Might have other side-effects, but OTT Pluto
 worked well with limited testing.

 My player needs to work with OS distributed builds so hooked the read-
 packet calls to trick mpegts into seek-after-segment. Will leave it to
 others to decide whether updating find_matching_streams makes sense. (Not
 possible to retrofit that behavior.)
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/8009#comment:7>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker