small guide: audio sync proceedure

[hms]

I like to post this: Perhaps someone may find this helpful:

Audio got out of sync gradually when making a home video DVD.
DVD specs do not allow changing frame rate:
I used a WAV editor to stretch the audio file.
Procedure:
1- Opened captured video file in VirtualDub
2- Under VIDEO FRAME RATE CONTROL checked “Change so video and audio durations match”
3- Copied down suggested values and calculated the difference.
4- Difference converted into time.
5- That time difference multiplied by total frames of the captured video file.
6- Extracted the audio file: Opened in a WAV editor and stretched (positive or negative) the audio file (Time Stretch only).
7- Saved the edited audio file and converted to AC3: Then muxed with the encoded MPEG video file.


My audio gradually delayed and therefore I had to shrink (negative time stretch) the audio file.
DVD then played in perfect sync.

[Benihana]

I'm not sure I understand what you mean by steps 3 - 5. Where are these "suggested values" reported, and what are you calculating the difference of? How are you converting this difference into time? And, where are you getting the calculated value for the audio time stretch? It's a good post, I messed around a little with VDub trying to get it to follow your post, but I'm a little lost. Clarification would be greatly appreciated, thanks.

[hms]

I have since simplified my methods:
With video cature I always have a problem with the audio sampling rate.
Now I simply open the video clip in VirtualDub Mod and under stream report I get the respective video and audio lenghths.
Just make or stretch the audio to the same length as the video.
I use CoolEdit 2000pro: Easy to open a wav audio or inserting an mpeg2 audio and easy to use the stretch option.
But CoolEdit will only save in WAV format but there are many free audio tools available to convert to a DVD complient audio stream.