![]() The ability to manipulate video so easily, without a UI, also makes for easy automation of media, especially when you combine this technique with clipping video - you get just the frames you want at the speed you want. I recently used this slow-mo technique on a highlights video downloaded from YouTube to draw my own conclusions about a specific play. doubling speed seems to require a different multiple. More confusing is that the atempo setting seems to require reverse logic to setpts i.e. ![]() If you care to sync the audio speed with the video speed, things get a bit more complicated: ffmpeg -i input.mp4 -filter_complex "setpts=0.5*PTS atempo=2.0" -map "" -map "" output.mp4 If you use a larger value, the video will display in slower motion. The lower the PTS value, the faster the time-lapse video is generated. It turns out all you need to do is pass in filter with a PTS ( presentation timestamp) value: Faster Video Speed ffmpeg -i input.mp4 -filter:v "setpts=0.5*PTS" output.mp4 Slower Video Speed ffmpeg -i input.mp4 -filter:v "setpts=2*PTS" output.mp4 Let’s say you want to extract a 23 second video starting at timestamp 1 min 45 seconds: ffmpeg -i inputVideo.mp4 -ss 00:01:45.0 -codec copy -t 23 outputVideo.mp4. ![]() ![]() One of my favorite TV sports illustration techniques is speeding video up (time-lapse) or slowing it way down (slo-mo replay) naturally I wanted to know how to manipulate video speed with ffmpeg. I don't have their advanced TV software or hardware, of course, but I do have a love for ffmpeg, which allows me to do everything from clip videos to change video formats, create tacky highlight videos with emo techno music combine audio and video, and more. I watch a lot of sports and recently I've become fascinated with some of the methodologies they use to illustrate events within the game.
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