For Faster video speeds use:

ffmpeg -i input.mov -filter:v "setpts=0.5*PTS" output.mov

For Slower video speeds use:

ffmpeg -i input.mov -filter:v "setpts=2*PTS" output.mov

Note the factor multiplying PTS. If that factor is less than 1, then you get a faster video. The opposite otherwise.

Thanks to:

Modify Video Speed with ffmpeg