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I own a Logitech c920 camera which seems to be able to do at least 24fps for 1080p (although the specs say it should go up to 60), according to vlc -vvv --color v4l2:///dev/video0 --run-time 1 vlc://quit -I dummy -V dummy -A dummy for which I get the lines:

[00007f64f4001120] v4l2 demux debug:  frame size 1920x1080
[00007f64f4001120] v4l2 demux debug:   discrete frame interval: 1/24

However, when I attempt to use ffmpeg to copy video0 to a v4l2 loopback device using:

ffmpeg -f v4l2 -r 24 -s 1280x720 -i /dev/video0 -codec copy -f v4l2 /dev/video4

I get only 10fps and the message:

[video4linux2,v4l2 @ 0x55a30e698c00] The driver changed the time per frame from 1/24 to 1/10

Why is this happening and how can I get a higher framerate?

umläute
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Paulo Matos
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1 Answers1

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You are using RAW format of the camera. Try using a compressed codec:

ffmpeg -vcodec mjpeg -r 30 -s 1920x1080 -f v4l2 ...
fmi
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