Audio Sync Workaround for Dummies Like Me

[oldsynthguy]

Always work in 48k audio. Always. My capture card will only do 44.1 and I was having a lot of sync probs from VHS/DV capture that did not involve drop frames or hardware issues. When I started re-setting the sample rate in Sound Forge (NOT resample, just changing rate to keep the timimg straight) I found I can burn and export to other formats without the sync problems.

All the video/DVD/authoring progs I have used take your video at render and stuff the audio into NTSC 48k audio, and they resample it when they convert, not just change the rate. Resampling changes the timing, rate change does not. A 1:13 audio file at 44.1 resamples to 1:19. If you just perform a native rate change via Sound Forge or other capable program, your file length stays the same.

So my Dummy Sync issue solution is always capture at output resolution (MPEG2, 720x480) and if the audio capture is less than 48k, change it, remux and render in sync.

[koic]

...re-setting the sample rate in Sound Forge (NOT resample, just changing rate to keep the timimg straight)...

Are you talking about check box Set sample rate only (do not resample) in Resample window ?
So you set rate to 48,000, check that box and that's it ?
But in my case the length changed from 1:17 to 1:10 !
Although the length of the file did not.

[mats.hogberg]

This sounds very odd to me - if SoundForge works as I believe it does, it just changes a flag in the wav, right? Then it's the same thing as playing a tape at a higher speed than it was recorded at, and ought to

• A) Sound chipmunky and
  B) Have a shorter duration.

Only situation where this method ought to work is where the original is indeed a 48 kHz wav, but with a 44.1 kHz header. But if it works, it works.

/Mats