• Graham Booker's avatar
    avformat/mpegtsenc: Changed Video PES packet length to 0. · 60fcc19b
    Graham Booker authored
    The rational for this is another issue that plex has exposed.  When it is
    conducting a transcode of video to HLS for streaming, my father noticed
    artifacts when played on his GoogleTV (NSZ-GT1).  He sent me a test file
    and I reproduced it on my device of the same model.  It is important to
    note that the artifacts were not present when streaming to VLC or QuickTime
    Player.  I copied the command-line that plex used, and conducted all of the
    following tests using FFmpeg git.
    
    Transcode to HLS: artifacts on playback
    Transcode to TS: playback is fine
    Cat HLS segments into a single TS: playback is fine
    Segment single TS file to segments: artifacts on playback
    Segment single TS file to segments using Apple's HLS segmenter: playback is
    fine
    
    At this point I carefully examined the differences between Apple's HLS
    segmenter output and FFmpeg's.  Among the considerable differences, I
    noticed that the video PES packets always had a 0 length.  So I continued:
    
    Transcode to HLS using FFmpeg with 0 length PES packets: playback is fine.
    Segment single TS to segments with 0 length PES packets: playback is fine.
    
    All failures mentioned are only on the GTV since it is the only player on
    which I could reproduce artifacts.  I only tested the GTV, VLC, and
    QuickTime Player though, so my test case is limited.  I do not know if
    other players exhibit this issue.
    
    Since it was useful last time, I have uploaded the test file as
    hls_pes_packet_length.m4v along with its associated txt file which contains
    the transcode command-line that was used.
    Reviewed-by: 's avatarKieran Kunhya <kierank@obe.tv>
    Signed-off-by: 's avatarMichael Niedermayer <michaelni@gmx.at>
    60fcc19b
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