[FFmpeg-trac] #2737(undetermined:new): There are discontinuous phenomenon in playing HLS stream when changing another bitrate stream

[FFmpeg]

#2737: There are discontinuous phenomenon in playing HLS stream when changing
another bitrate stream
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             Reporter:               |                    Owner:
  felixyang_tw                       |                   Status:  new
                 Type:  enhancement  |                Component:
             Priority:  wish         |  undetermined
              Version:  git-master   |               Resolution:
             Keywords:  HLS          |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
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Comment (by anssi):

 This is because HLS demuxer defers playlist reconfigs to segment switch
 times (I guess to try to achieve "clean" switches between streams without
 requesting overlapping segments from different variants).

 However, when ffplay switches between streams, it does so "immediately" so
 that the packets from the HLS demuxer now get all ignored as they are from
 the current segment of the previous variant stream.

 Either a) ffplay should continue playing the old stream until the first
 packet of the new stream arrives, or b) HLS demuxer should immediately
 switch to the new variant mid-segment.

 Of course, with the b) option there would still be a (smaller) jump as
 ffplay needs to wait for a keyframe (IIRC). However, something like the b)
 option should be added anyway at least for alternative renditions, since
 one should be able to switch audio track or subtitle track without too
 much delay (and subtitle tracks may have very long segment times). I'm not
 100% sure yet if it is a good idea for variant streams as well, though.

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Ticket URL: <https://trac.ffmpeg.org/ticket/2737#comment:6>
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