[FFmpeg-trac] #2882(avdevice:closed): ffmpeg can't save h264 stream from v4l2 webcam into file without recoding

[FFmpeg]

#2882: ffmpeg can't save h264 stream from v4l2 webcam into file without recoding
------------------------------------+------------------------------------
             Reporter:  pchel       |                    Owner:
                 Type:  defect      |                   Status:  closed
             Priority:  normal      |                Component:  avdevice
              Version:  git-master  |               Resolution:  fixed
             Keywords:  v4l2 h264   |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
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Comment (by pchel):

 Replying to [comment:22 cehoyos]:
 > > {{{
 > >  frame=  149 fps= 27 q=0.0 Lsize=    3569kB time=00:00:05.02
 bitrate=5823.7kbits/s dup=71 drop=7
 > > }}}
 > Looks as if the input frame rate is really ~15fps, don't you agree?

 I can't agree. When I run the command with mpeg encoding for a minute I
 get following

 {{{
 frame=  648 fps= 30 q=0.0 size=   14966kB time=00:00:22.80
 bitrate=5374.8kbits/s
 frame=  663 fps= 30 q=0.0 size=   15387kB time=00:00:23.28
 bitrate=5414.1kbits/s
 frame=  677 fps= 30 q=0.0 size=   15724kB time=00:00:23.81
 bitrate=5409.1kbits/s
 frame=  689 fps= 29 q=0.0 size=   16012kB time=00:00:24.32
 bitrate=5392.0kbits/s
 frame=  711 fps= 30 q=0.0 size=   16461kB time=00:00:24.82
 bitrate=5432.4kbits/s
 frame=  725 fps= 30 q=0.0 size=   16812kB time=00:00:25.32
 bitrate=5437.5kbits/s
 frame=  740 fps= 30 q=0.0 size=   17190kB time=00:00:25.88
 bitrate=5440.6kbits/s
 frame=  752 fps= 29 q=0.0 size=   17495kB time=00:00:26.39
 bitrate=5429.6kbits/s
 frame=  774 fps= 30 q=0.0 size=   17927kB time=00:00:26.82
 bitrate=5475.0kbits/s
 frame=  786 fps= 30 q=0.0 size=   18220kB time=00:00:27.41
 bitrate=5443.8kbits/s
 frame=  801 fps= 30 q=0.0 size=   18552kB time=00:00:27.90
 bitrate=5445.4kbits/s
 frame=  815 fps= 30 q=0.0 size=   18862kB time=00:00:28.42
 bitrate=5436.5kbits/s
 frame=  829 fps= 30 q=0.0 size=   19317kB time=00:00:28.95
 bitrate=5465.0kbits/s
 frame=  849 fps= 30 q=0.0 size=   19662kB time=00:00:29.46
 bitrate=5466.1kbits/s
 frame=  862 fps= 30 q=0.0 size=   20009kB time=00:00:29.93
 bitrate=5475.1kbits/s
 frame=  876 fps= 30 q=0.0 size=   20352kB time=00:00:30.47
 bitrate=5471.6kbits/s
 frame=  890 fps= 30 q=0.0 size=   20815kB time=00:00:30.96
 bitrate=5507.1kbits/s
 frame=  912 fps= 30 q=0.0 size=   21191kB time=00:00:31.49
 bitrate=5512.4kbits/s
 frame=  924 fps= 30 q=0.0 size=   21479kB time=00:00:31.98
 bitrate=5501.4kbits/s
 frame=  938 fps= 30 q=0.0 size=   21894kB time=00:00:32.49
 bitrate=5519.3kbits/s
 frame=  951 fps= 30 q=0.0 size=   22227kB time=00:00:32.98
 bitrate=5519.6kbits/s
 frame=  956 fps= 30 q=0.0 Lsize=   22385kB time=00:00:33.25
 bitrate=5514.9kbits/s dup=475 drop=7
 video:21817kB audio:529kB subtitle:0 global headers:0kB muxing overhead
 0.172394%

 }}}

 So the fps is 30.

 Also as ffmpeg output

 {{{
 Stream #1:0: Video: h264 (Constrained Baseline), yuvj420p(pc), 1920x1080
 [SAR 1:1 DAR 16:9], -5 kb/s, 30 fps, 30 tbr, 1000k tbn, 60 tbc
 }}}

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Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2882#comment:23>
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