speed up mp4/mp3 with ffmpeg

you may need to download latest ffmpeg

if there are issues with ffmpeg filter options.

szenario: You're having some training videos (mp4) and want to listen to them faster.

Option #1: mp4 to mp3, and speedup (in one step):

create mp3 from mp4 and change the tempo while doing this.

ffmpeg -i input.mp4  -filter:a "atempo=1.8" output.mp3 

Option #2: speedup video (no mp3 conversion):

create mp4 and double the tempo

ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" output.mp4

For more information, visit: https://trac.ffmpeg.org/wiki