With much help from @monoidmusician here's how to use #ffmpeg 7.1.1 to re-encode a video for a #TinyTV 2 [1]

I'm using the ffmpeg in NixOS 25.05 in case that helps.

ffmpeg -i input.mp4 -r 24 -pix_fmt yuv420p -vf 'scale=210:135,format=yuv444p,pad=210:135:(ow-iw)/2:(oh-ih)/2,format=yuv420p,hqdn3d' -b:v 1500k -c:v mjpeg -ac 1 -acodec pcm_u8 -af 'volume=0.0dB,aresample=10000,aresample=async=1000,aresample=osf=u8,asetnsamples=n=210:p=0' -y output.avi

[1] https://tinycircuits.com/products/tinytv-2