Hi everyone,
I am using the vokoscreenNG version 4.0.0. It works great! 
However, only one VP8 video codec and one MP3 audio codec are available.
This is very little for a full-fledged job.
How can I add additional codecs to it?
the x264 is in gst-plugins-ugly
That is what i have, VP8 and x264.
Install the optional dependencies gst-plugins-bad and gst-plugins-ugly for H.264 video and AAC audio. If you need more than that then just use another application like Handbrake to transcode into whatever format you want.
I use TV-Box GT-King, Gqrx and vokoscreenNG software to record waterfall and sound “on the fly” using VP8 codec.
The VP8 codec turned out to be very voracious, and GT-King performance is not enough, and the sound is constantly choking, and the processor temperature rises to 85 degrees.
Therefore, I need another video and audio codec for vokoscreenNG that minimally loads the system.
On such TV boxes H264 is usually hardware supported for decoding, i do not know if it is true for encoding. Just try and tell us if it is better with it.
Your options in vokoscreenNG are H.264 and AAC as already described. If those don’t work for you then you’ll have to find a different recorder application that supports the codecs you need.