TMPGEnc, ASF and sync issues

[kevinm]

Experts, hopefully this is the right forum for this question, I believe that it relates to encoding not capturing ..


I have been battling for some time to get iuVCR to produce AVI with the audio & video in sync. Recently the author of iuVCR pointed me to their ASF writer.

I was told this would give me perfect audio/video sync. This appear to be true going by what I see when I play in Media Player BUT after encoding in TMPGEnc that is another thing altogether!


I load the ASF into TMPGEnc, frameserving using avisynth. I encode using standard PAL DVD template and view the results in WinDVD, I also authored to DVD using TMPG DVD Author. Whatever method I choose to view the result from TMPGEnc the audio and video are out of sync. After 1hr 14mins the audio is late relative to the video by about two seconds.

I am not very familiar with ASF, all I know is that it is an option for iuVCR as (unlike AVI) it allows for time stamps, so has the possibility of keeping the audio and video synchronized.

Does anyone have any suggestions on how I should proceed, should I give up on TMPGEnc for the audio and extract it from the ASF using some other tool (e.g Lame) ?

I have been struggling with this for weeks, I thought that the iuVCR guys had given me the answer with ASF but that is only any use if I want to use Media Player to play the captured video!

thanks in advance,

Kevin

[kevinm]

At the suggestion of the author of iuVCR I have encoded the captured video (ASF) from iuVCR using Mainconcept 1.4, the audio sync problem is still there, in fact it is far worse.

Does anyone know of any tool I can use to analyze the ASF to check the alignment of the audio & video frames?

thanks,

Kevin

[kevinm]

oh well, I guess I must have posted a dumb question since no one has any input (yet), anyway in case anyone is following this thread I thought I would answer my last question myself ..

I found a program called SyncView, this was useful in determining the extent of the sync error. I have determined that at the 1hr 14min point the audio is late by 570mS. The start of the video, the audio is in sync.

SyncView was able to load the ASF as the video stream but had problems loading the audio so I used VirtualDub 1.3d to extract a WAV from the ASF and fed that into SyncView. At this point I am assuming that VirtualDub extracted the audio corrctly and I can trust the sync error number from SyncView.

If the sync error is consistent for all captures that I am planning to do then I should be able to change the pitch of the audio to correct the sync problem. Question is ..

1. will the audio from my iuVCR capture always be out by the same percentage?

2. is there any way to get TMPGenc to use the time stamps from the ASF in the same way as Media Player seems to do?

3. Is there any way to use AVISynth to use the ASF time stamps and feed the audio to TMPGEnc in such a way that the audio is always in sync? (probably need to post this question to the AVISynth forum)

Kevin