For your "output dir" this app use the source directory as output directory, you cant configure this now. I want to add it when i have time.
For config :
https://hub.docker.com/r/chacawaca/post-recording
Configuration:
/scripts/custom.sh need to be configured by you, some example are there to help you configure this for your need.
Help with Intel
Intel GPU Use
Edit your go file to include:
modprobe i915, save and reboot, then
add --device=/dev/dri to "extra parameters" (switch on advanced view)
For your FFmpeg command, it is specific for your need, i cant help you, im not a ffmpeg specialist too and i havent test your specific output.
you can start with command in intel.sh.example and modify it for you need, change audio to copy and modify encoding for hardware h264.
You will have to do some search about ffmpeg, so much parameter exist.