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I'm trying to speed up the playback of mp4 video files. I'm able to speed-up playback on Windows using VLC but I'd like to convert the file so it will always play 1.25 faster than normal speed regardless of what software it is being played in.

I have had some success using Sony Vegas for this task but I'd ideally like to find something that would run a batch process to convert a number of videos. Does anyone have any suggestions?

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You can use mencoder - see this answer I just gave. mencoder has a Windows version available so if you don't have it already, you should be able to download and install it. The command would be something like

mencoder -speed 1.25 -o output.mp4 -ovc lavc input.mp4

I don't know if it can do its own batch processing, though; you might have to write a little wrapper script or something to run it once on each file you want to convert.

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Audio file can be speed up using sox command, refer #13: sox tutorial

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You can use VirtualDub to re-encode your video with a higher playback speed.

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Doesn't support MP4 – Scott Weinstein Aug 6 '12 at 12:50
If you install QuickTime plugin for VirtualDub, it will. – Mehper C. Palavuzlar Aug 6 '12 at 13:33

FFmpeg is able to do this very well. Mencoder always had issues where FFmpeg seemed to work flawlessly.

ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=0.8*PTS[v];[0:a]atempo=1.25[a]" -map "[v]" -map "[a]" output.mp4

Just make sure to change the input and output filenames (wrap filenames in quotations if necessary for spaces).


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