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On Raspbery Pi's Raspbian (based on Debian Wheezy) I'm trying to make a simplest video grab from a Logitech C910 webcam to a video file via ffmpeg/avconv.

I say:

$ avconv -t 5 -f video4linux2 -s 320x240 -r 30 -i /dev/video0 -vcodec mpeg1video out.avi

but get

avconv version 0.8.6-6:0.8.6-1+rpi1, Copyright (c) 2000-2013 the Libav developers
  built on Mar 31 2013 13:58:10 with gcc 4.6.3
[video4linux2 @ 0x1371840] Cannot find a proper format for codec_id 0, pix_fmt -1.
/dev/video0: Input/output error

Line video4linux2 suggests, that the problem is with input codec, not output?

May be I haven't installed some package?

What's wrong? Seems, that solution should be very simple. Thanks.

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@slhck Edited post. Hardware is Logitech C910 camera and Raspberry Pi (so to be precise OS is Raspbian, not Debian Wheeze). – Bob Apr 30 '13 at 12:40

I saw this problem on my logitech C310 and raspbian. After some more poking around i found some help with the pixel format needed.

$ sudo apt-get install v4l-utils
$ sudo v4l2-ctl --list-formats
    ioctl: VIDIOC_ENUM_FMT
    Index       : 0
    Type        : Video Capture
    Pixel Format: 'YUYV'
    Name        : YUV 4:2:2 (YUYV)

    Index       : 1
    Type        : Video Capture
    Pixel Format: 'MJPG' (compressed)
    Name        : MJPEG

adding "-pix_fmt yuyv422" to the ffmpeg command line got it going again.

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