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  1. Hello,

    I'm trying to grab video from Logitech 920C web cam using very slow frame rate: 1 frame / 180 sec (three minutes). I have tested with ffmpeg and avconv as follows:

    Code:
    avconv -t 3600 -f video4linux2  -s hd1080 -i /dev/video0 -r 1/180 -f avi -vcodec mpeg4   /home/pi/Videot/testvideo-$(date +%d.%m.%Y_%H.%M).avi
    It seems that ffmpeg (avconv) can do -r 1/180 with no problem. However, web cam appears support only 1/20 (3 frames / minute).

    What would be the best workaround to obtain the frame rate I want?
    Secondly, option -t seems not to have effect with when using avconv, with ffmpeg it works ok. I wonder if the order of options is correct in my expression?

    I'm using Raspberry Pi with Rasbian as a platform.

    Thanks for help.
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  2. I'm a MEGA Super Moderator Baldrick's Avatar
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    Moving you to our video capture section. This is only for ffmpegx and not ffmpeg or libav.
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  3. I'm a MEGA Super Moderator Baldrick's Avatar
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    Maybe make a script that just captures one image every 180 sec?

    You can then put together all images to a video with ffmpeg.
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  4. Thanks for the idea. Simple script does what I want.

    Code:
    #!/bin/bash
    for i in {0..200..1} # here how many frames are needed
            do
                    ffmpeg -f video4linux2  -s hd1080 -i /dev/video0 -vframes 1 -f avi -vcodec copy pipe: | ffmpeg -i pipe: -f avi -vcodec mpeg4  pipe: | cat >>  /home/pi/Videot/frames/testvideo.avi
                    sleep 180
            done
    exit 0
    Obviously not the most elegant script but it does the job. If someone has better ideas, I'm willing to know.

    Thanks,
    Viivi
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