[FFmpeg-user] Error when using v4l2 to encode H264

Bogdan Mariesan bogdan.mariesan at buddyguard.io
Mon May 16 14:20:20 CEST 2016


FFmpeg command:
 ./ffmpeg -f v4l2 -video_size 640x360 -rtbufsize 702000k -framerate 30 -i
/dev/video0 -r 30 -threads 4 -vcodec libx264 -pix_fmt yuv420p -tune
zerolatency -preset ultrafast test.avi


FFMpeg log:

user at chrysaor-info-ubuntu-14041-desktop-amd64:~/ffmpeg/FFmpeg$ ./ffmpeg -f
v4l2 -video_size 640x360 -rtbufsize 702000k -framerate 30 -i /dev/video0 -r
30 -threads 4 -vcodec libx264 -pix_fmt yuv420p -tune zerolatency -preset
ultrafast test.avi
ffmpeg version N-80003-g2f76157 Copyright (c) 2000-2016 the FFmpeg
developers
  built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.1)
  configuration: --enable-nonfree --enable-gpl --enable-libx264
--enable-x11grab --enable-zlib
  libavutil      55. 24.100 / 55. 24.100
  libavcodec     57. 42.100 / 57. 42.100
  libavformat    57. 36.100 / 57. 36.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 45.100 /  6. 45.100
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
Input #0, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, bitrate: 110592 kb/s
    Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 640x360,
110592 kb/s, 30 fps, 30 tbr, 1000k tbn
[libx264 @ 0x38be2c0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2
AVX FMA3
[libx264 @ 0x38be2c0] profile Constrained Baseline, level 3.0
[avi @ 0x38bca20] Using AVStream.codec to pass codec parameters to muxers
is deprecated, use AVStream.codecpar instead.
Output #0, avi, to 'test.avi':
  Metadata:
    ISFT            : Lavf57.36.100
    Stream #0:0: Video: h264 (H264 / 0x34363248), yuv420p, 640x360, q=2-31,
30 fps, 30 tbn
    Metadata:
      encoder         : Lavc57.42.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
Could not write header for output file #0 (incorrect codec parameters ?):
Immediate exit requested

When going through ffserver my capture was hanging so I tried to output it
to a file. It still hangs and when I try to stop it I get the log above.

*Bogdan Emil Mariesan*
Senior Software Engineer

*BuddyGuard UG* (haftungsbeschränkt)
Dircksenstr. 40
10178 Berlin

m:         +40 743 901 331
w.           www.buddyguard.io


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