The x264 encoding guide gives a nice explanation of the different options for H.264 encoding. Normally:
ffmpeg -i in.avi -strict experimental -crf 23 -preset medium out.m4v |
Where you can deviate from the above defaults:
- -crf [18-28]
- perceived output quality (lower crf is better quality)
- -preset [ultrafast,superfast,veryfast,faster,fast,medium,slow,slower,veryslow]
- compression effort (slower preset is better compression)