uvc-gadget using 98% CPU when not in use

[geerlingguy]

It would be nice if the uvc-gadget process were not quite as much of a CPU hog, at least on the Pi Zero W's ancient CPU.

top - 21:56:20 up 4 min,  3 users,  load average: 0.99, 1.36, 0.68
Tasks: 111 total,   2 running, 109 sleeping,   0 stopped,   0 zombie
%Cpu(s): 16.9 us, 83.1 sy,  0.0 ni,  0.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
MiB Mem :    368.7 total,     82.5 free,    100.0 used,    186.2 buff/cache
MiB Swap:    100.0 total,    100.0 free,      0.0 used.    215.2 avail Mem 

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND                                                                                                                        
  436 root      20   0    5940   5168   5100 R  98.4   1.4   2:30.20 uvc-gadget

Is there any way to bring that down? Right now I'm testing supplying a 720p and 1080p stream... maybe I can't have multiple, and I'll have to stick with just one.

[fallingcats]

The Pi is usually way more efficient in encoding h264 (gpu accelerated) than mjpeg from what I've seen. I don't know whether is is possible to switch but it should certainly be worth looking into

[fallingcats]

For what it's worth I found this, which seems to support h264
https://github.com/gale320/uvc-gadget/blob/master/uvc-gadget.c

Edit: Seems support for h264 is (a) not tested, and (b) probably not quite functional(?)
gale320/uvc-gadget@8934956

[geerlingguy]

Related: wlhe#1