Arch Linux

TomB17

Member

Registered: 2009-09-02

Posts: 102

accessing /dev/video0 locks kernel tight

When I try to access a v4l2 device, the screen turns black and my kernel locks.  I have to hard reset to get the system back.  The box stops responding to pings, mouse pointer locks tight, screen turns back with flashing cursor in top left...

This code will lock up my machine:

ffmpeg -s 320x240 -f video4linux2 -i /dev/video0 output.ogv

Confusingly, I can launch vlc and media->capture device, select video4linux2, and enter /dev/video0 in the video device name field.  That works.  It even streams video.  It's working right now.

Here is my kernel.

2.6.33-ARCH #1 SMP PREEMPT Sun Apr 4 10:27:30 CEST 2010

I would appreciate some ideas.  How come vlc works but ffmpeg doesn't?  I've also tried ffmpeg2theora.  It behaves the same as ffmpeg.

Here is the output from "ffmpeg -version":

FFmpeg version SVN-r22837, Copyright (c) 2000-2010 the FFmpeg developers
  built on Apr 11 2010 19:46:29 with gcc 4.4.3 20100316 (prerelease)
  configuration: --prefix=/usr --enable-gpl --enable-libmp3lame --enable-libvorbis --enable-libfaac --enable-libfaad --enable-libxvid --enable-libx264 --enable-libtheora --enable-postproc --enable-shared --enable-pthreads --enable-x11grab --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-version3 --enable-nonfree --enable-runtime-cpudetect
  libavutil     50.14. 0 / 50.14. 0
  libavcodec    52.66. 0 / 52.66. 0
  libavformat   52.61. 0 / 52.61. 0
  libavdevice   52. 2. 0 / 52. 2. 0
  libswscale     0.10. 0 /  0.10. 0
  libpostproc   51. 2. 0 / 51. 2. 0
FFmpeg SVN-r22837
libavutil     50.14. 0 / 50.14. 0
libavcodec    52.66. 0 / 52.66. 0
libavformat   52.61. 0 / 52.61. 0
libavdevice   52. 2. 0 / 52. 2. 0
libswscale     0.10. 0 /  0.10. 0
libpostproc   51. 2. 0 / 51. 2. 0

Last edited by TomB17 (2010-04-17 14:49:00)