MPEG-TS Segments HTTP Live Streaming

问题

I'm trying to interleave MPEG-TS segments but failing. One set of segments was actually captured using the built in camera in the laptop, then encoded using FFMPEG with the following command:

ffmpeg -er 4 -y -f video4linux2 -s 640x480 -r 30 -i %s -isync -f mpegts -acodec libmp3lame -ar 48000 -ab 64k -s 640x480 -vcodec libx264 -fflags +genpts -b 386k -coder 0 -me_range 16 -keyint_min 25 -i_qfactor 0.71 -bt 386k -maxrate 386k -bufsize 386k -qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 -aspect 640:480

And the other one is an avi file that was encoded using the following command:

fmpeg -er 4 -y -f avi -s 640x480 -r 30 -i ./DSCF2021.AVI -vbsf dump_extra -f mpegts -acodec libmp3lame -ar 48000 -ab 64k -s 640x480 -vcodec libx264 -fflags +genpts -b 386k -coder 0 -me_range 16 -keyint_min 25 -i_qfactor 0.71 -bt 386k -maxrate 386k -bufsize 386k -qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 -aspect 640:480

Then the output is segmented into ts segments using an open source segmenter.

If both come from the same source (both from the camera) they work fine. However in this case, the second set of segments freeze. Time passes, but the video does not move.. So i think it's an encoding problem. So my question is, how should i change the ffmpeg command for this to work?

By interleave I mean, having a playlist with the first set of segments, and another playlist with the other set of segments, and having the client call one then the other (HTTP Live Streaming)

The ffprobe output of one of the first set of segments:

Input #0, mpegts, from 'live1.ts':
  Duration: 00:00:09.76, start: 1.400000, bitrate: 281 kb/s
  Program 1 Service01
    Metadata:
      name            : Service01
      provider_name   : FFmpeg
    Stream #0.0[0x100]: Video: h264, yuv420p, 640x480 [PAR 1:1 DAR 4:3], 29.92 fps, 29.92 tbr, 90k tbn, 59.83 tbc
    Stream #0.1[0x101]: Audio: aac, 48000 Hz, stereo, s16, 111 kb/s

The ffprobe output of one of the second set of segments:

Input #0, mpegts, from 'ad1.ts':
  Duration: 00:00:09.64, start: 1.400000, bitrate: 578 kb/s
  Program 1 Service01
    Metadata:
      name            : Service01
      provider_name   : FFmpeg
    Stream #0.0[0x100]: Video: h264, yuv420p, 640x480 [PAR 1:1 DAR 4:3], 25 fps, 25 tbr, 90k tbn, 50 tbc
    Stream #0.1[0x101]: Audio: aac, 48000 Hz, stereo, s16, 22 kb/s

Thank you,

回答1:

I have seen quite a few questions in the subject - See:

HTTP Live Streaming MPEG TS segment and
Update .m3u8 playlist file for HTTP Live streaming?

I am not sure exact problem - but i think most people complain that when you mix content from both sources are different then there is a freezing.

I think this situation may arise if PTS and/or PCR is discontinuous and the player is not recognizing this or flushing it. Probably, you can identify the sequence of Timestamps and see if that being fixed solves the problems.

Also, see 3.3.11. of http://tools.ietf.org/html/draft-pantos-http-live-streaming-07 : EXT-X-DISCONTINUITY

The EXT-X-DISCONTINUITY tag indicates an encoding discontinuity
between the media segment that follows it and the one that preceded
it. The set of characteristics that MAY change is:

o file format
o number and type of tracks
o encoding parameters
o encoding sequence
o timestamp sequence

So a discontinuity flag in the playlist file might just help if the problem is any of the above. Please try some of this, and put more details. I guess, this will help lot of other people as well.

来源：https://stackoverflow.com/questions/8635666/mpeg-ts-segments-http-live-streaming

标签

encoding

ffmpeg

http-live-streaming

playlist

mpeg