I needed to speed up video and found this post. I also needed to remove the audio track which you can do with the -an option.
The command ended up looking like:
ffmpeg -i invideo.mp4 -vf "setpts=(1/<multiplier>)" -an outvideo.mp4
I then wanted to trim some time off the video. This post was helpful and I ended up with
ffmpeg -i invideo.mp4 -vcodec copy -acodec copy -ss 00:00:03.000 outvideo.mp4
I only needed to trim 3 seconds off the beginning. I am sure there is a way to combine the two commands.