ffmpeg commandline for maximum compatibility

An old Raspberry Pi was not playing some videos. Looked around for a transcoding option with ffmpeg, baseline x264 seemed fine, and this example worked for me -

ffmpeg -i input.avi -c:v libx264 -preset slow -crf 22 -c:a copy -profile:v baseline -level 3.0 output.mp4

by looking at

https://trac.ffmpeg.org/wiki/Encode/H.264

Another post has the 2-pass encoding example, where the bitrate is also specified.