When following this guide on my RPi 4 running Ubuntu Server 20.04.1 LTS, there is no output at step 3 (v4l2-ctl --stream-mmap --stream-count=-1 -d /dev/video0 --stream-to=/dev/null). However, the command v4l2-ctl -V returns the following:
Format Video Capture: Width/Height : 1280/800 Pixel Format : 'Y10P' (10-bit Greyscale (MIPI Packed)) Field : None Bytes per Line : 1600 Size Image : 1280000 Colorspace : sRGB Transfer Function : sRGB YCbCr/HSV Encoding: ITU-R 601 Quantization : Full Range Flags :so it is clear that v4l2 is detecting camera.
This is the same issue found in this thread, although I’m on a RPi 4 instead of 3. Following the advice of that thread, I tried disabling the ov9281 overlay and installing the MIPI driver on github. The installation appears to be successful, but ./arducamstill returns init camera status = 4099. In any case, I would strongly prefer to use the built-in driver over a 3rd party one.