Random ffmpeg tricks
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Forcing a webcam (/dev/video2) to appear as 720p60 (/dev/video4)
sudo modprobe v4l2loopback card_label="V4L2LoopBack"
ffmpeg -re -f v4l2 -framerate 60 -video_size 1280x720 -c:v mjpeg -i /dev/video2 \
-pix_fmt yuyv422 -f v4l2 /dev/video4