Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I need to fix up a video file. The video length is suspected to be 10:01.645. The audio length is 10:20.931. When i use virtual dub to combine the audio and video i can see its very far from sync. How do i speed up the audio so it matches the video length? I know it wont be perfect but its better then being +2 second off every minute. (at the 9minute mark its noticeable something is 15+ seconds behind)

share|improve this question
    
How about we start with you telling us which program your using to edit your video. –  wizlog Nov 27 '11 at 16:02

2 Answers 2

If you can break the audio out into its own file, you can use Audacity to change the speed. It may take a little bit of trial and error, but for a starting point, +3% is pretty close to what you need.

  1. Open the file in Audacity
  2. Ctrl+A to select the entire file
  3. Select Effect -> Change Speed... and enter the desired difference.
  4. Click OK

Note that Change Tempo performs a similar function, and tries not to change the pitch. However, because it tries to keep the pitch the same, there will be some distortion, which may be undesirable.

share|improve this answer
1  

Could you reduce the framerate of the video instead? Stretching audio often sounds strange, but altering the video framerate should come out the same.

Subtract 3% from the frame rate and it will match the audio.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.