How to speed up video files?

April 23, 2009 1:53 PM

How do I speed up AVI video files by 35% ?

I use an audio editing app called GoldWave to speed up MP3s (great for podcasts). Using the "Time Warp" effect, I can increase the tempo while keeping the pitch the same (so people don't sound like chipmunks).

Is it possible to do this with videos?

posted by blahtsk to computers & internet (5 comments total)

Suggestions, links, and comments here.

Summary: Re-encoding is probably not necessary, there are players for every major platform that can handle this.
posted by silentbicycle at 2:00 PM on April 23

VLC and Media Player Classic (Home Cinema, or not) do this, and Mplayer should as well.
posted by Inspector.Gadget at 2:22 PM on April 23 [1 favorite]

You can do this with VirtualDub and Audacity/GoldWave. It is not a one step process.

It goes something like this:
1 Open your video in VirtualDub
2 File> Export> Raw Audio and export the audio
3 Video> Frame Rate> look at the current frame rate number, and calculate what a 35% increase would be. Change the frame rate to that. (If your frame rate is 25fps change it to 34 fps)
4 Video> Direct Stream Copy
5 Audio> No Audio
6 File> Save as AVI
7 Open your new AVI and see how long it is (down to the millisecond).
8 Use Audacity/GoldWave to change the length of your exported audio to the length of the AVI.
9 Open your new faster AVI in VirtualDub
10 Audio> Audio From Other File select the new faster audio track.
11 Video> Direct Stream Copy
12 6 File> Save as AVI

(You will probably have to play with this to make it work perfectly.)
posted by gregr at 2:35 PM on April 23

Can Soundforge do it?
posted by jfrancis at 2:54 PM on April 23

I had to update VLC and enable a plugin, but it works great. Thanks.
posted by blahtsk at 3:27 PM on April 23