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• Revision 88538 : ce coeff delay n’a plus de sens maintenant qu’on fait un seul hit ...

  9 avril 2015, par cedric@… — Log

  ce coeff delay n’a plus de sens maintenant qu’on fait un seul hit gravatar qu’on soit en gravatar simple ou en gravatar+identicon|wavatar|monsterid

• Converting MP4 to HLS via ffmpeg producing stream with start delay

  24 mai 2018, par Eugene Alexeev

  I’m trying to convert mp4 to hls via this FFMpeg command :

  ffmpeg -i 1.mp4 -vcodec copy -q:v 5 -hls_time 5 -hls_list_size 0 -f hls 1.m3u8

  Command is working fine, without any errors whatsoever. BUT, when I’m trying to play brand-new HLS stream locally I noticed that it has a fixed start delay. I checked metadata of stream with ffprobe 1.m3u8 And that’s what I got :

  Input #0, hls,applehttp, from '1.m3u8':
 Duration: 00:00:11.17, start: 1.400000, bitrate: 0 kb/s
 Program 0
   Metadata:
     variant_bitrate : 0
   Stream #0:0: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p(tv, smpte170m/bt709/bt709), 720x1280, 30 fps, 30 tbr, 90k tbn, 180k tbc
   Metadata:
     variant_bitrate : 0

  As you can see, parameter start has value of 1.400000 and I believe that’s the reason of this annoying start delay. My question is - how can I get rid of that ?

  I tried to set start time with -ss flag but it doesn’t affect an output at all. Also input is perfectly fine, I tried to convert it with the same command but to .mp4 and I got correct results. Am I missing something here ? I would be very appreciated for any help. Thanks.

• ffplay got extra delay seconds than ffmpeg

  14 juillet 2017, par jiandingzhe

  I am working on low-latency video streaming. When I was making some tests, I noticed ffplay got much extra latency than ffmpeg, though they are the same software package.

  The video is encoded in H.264, size 320x240, 15fps. The stream is packed in FLV format, uploading and receiving are both done via RTMP. ffmpeg is called fairly simple :

  $ ffmpeg -i 'rtmp://my.path.to/my_rtmp_stream' -f sdl window_title

  And ffplay is also called in simple way :

  $ ffplay 'rtmp://my.path.to/my_rtmp_stream'

  The ffmpeg would starts to show the video instantly, and plays the video with minor latency (<0.5s) ; while ffplay would start the video in 5 seconds, and introduce a delay of 8 seconds.

  I further optimized the ffplay way, by minimizing probe size :

  $ ffplay -probesize 32 'rtmp://my.path.to/my_rtmp_stream'

  In this way, the startup goes quickly, but the delay is still 3 seconds.

  Why they behave so differently ?