VideoHelp Forum

Try DVDFab and download streaming video, copy, convert or make Blu-rays,DVDs! Download free trial !
+ Reply to Thread
Results 1 to 4 of 4
Thread
  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.
    Quote Quote  
  2. I'm a MEGA Super Moderator Baldrick's Avatar
    Join Date
    Aug 2000
    Location
    Sweden
    Search Comp PM
    Moving you to our video capture section. This is only for ffmpegx and not ffmpeg or libav.
    Quote Quote  
  3. I'm a MEGA Super Moderator Baldrick's Avatar
    Join Date
    Aug 2000
    Location
    Sweden
    Search Comp PM
    Maybe make a script that just captures one image every 180 sec?

    You can then put together all images to a video with ffmpeg.
    Quote Quote  
  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
    Quote Quote  



Similar Threads