kajtielplu

New Member
My Logitech C920 (serial number: 8E6EF41F) is set to YUYV 4:2:2 by default. With YUYV, I am unable to use HD video dimensions and also have an FPS higher than 10.
Screenshot from 2020-08-21 09-30-01.png

Using the following command, I can set it to use H264.
Code:
v4l2-ctl -d 1 --set-fmt-video=pixelformat=H264
However, when I open OBS, the pixel format is set to YUYV again.
How can I stop OBS overriding my video settings?
Log file is attached.
 

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  • 2020-08-21 09-25-08.txt
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Tuna

Member
The v4l2src plugin can only deal with uncompressed video - or with the so called "emulated" modes (where it appears uncompressed, but internally uses a compressed format).
 

DrYak

New Member
Just to complete/clarify the answer (because I was struggling against the same problem and this question is the first that pops up when googling the keywords):

  • When selecting "YUYV4:2:2" - OBS Studio pulls raw YUV422 frames all the way from the camera over USB2.0 (hence the fps limit due to USB2 bandwith limitations)
  • When selecting, eg.: "YU12 (emulated)" - the camera feed a compressed H264 stream over the USB2.0 link (no bandwidth limitation, full 30fps available) and the V4L2 decompresses it locally on the CPU and provides the requested format to OBS
 
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