I’m using a HDMI capture card to use a regular mirrorless camera as a webcam. This works great at 1080p or 720p resolutions, but the capture card does not only offer resolutions with 16:9 aspect ratio, but also with 4:3. If such a resolution is selected, then the video signal is stretched/distorted. Unfortunately one of the programs I’m using always chooses such a distorted resolution.
Here is the output of v4l2-ctl -d /dev/video0 --list-formats-ext:
ioctl: VIDIOC_ENUM_FMT
Type: Video Capture
[0]: 'MJPG' (Motion-JPEG, compressed)
Size: Discrete 1920x1080
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 1600x1200
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 1360x768
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 1280x1024
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 1280x960
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.020s (50.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 1024x768
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.020s (50.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 800x600
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.020s (50.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 720x576
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.020s (50.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 720x480
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.020s (50.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 640x480
Interval: Discrete 0.017s (60.000 fps)
Interval: Discrete 0.020s (50.000 fps)
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
[1]: 'YUYV' (YUYV 4:2:2)
Size: Discrete 1920x1080
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 1600x1200
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 1360x768
Interval: Discrete 0.125s (8.000 fps)
Size: Discrete 1280x1024
Interval: Discrete 0.125s (8.000 fps)
Size: Discrete 1280x960
Interval: Discrete 0.125s (8.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 1024x768
Interval: Discrete 0.100s (10.000 fps)
Size: Discrete 800x600
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 720x576
Interval: Discrete 0.040s (25.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 720x480
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Size: Discrete 640x480
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.050s (20.000 fps)
Interval: Discrete 0.100s (10.000 fps)
Interval: Discrete 0.200s (5.000 fps)
Is there a way to disable some of these resolutions, so that software accessing the webcam does not pick a non-16:9 aspect ratio?
