Audio conversion generates sync probs...

[wazp]

Hi!

Been trying to make a vcd-dvd for the last couple of days, but I just can't manage to get the sound to sync.

I've followed the guide here on vcdhelp, but the sound keeps getting a different length than the video.

Things I've tried so far:
1. Simple de-multiplex in TMPGEnc
2. Audio conversion to 48000Hz using TMPGEnc/ssrc.exe
3. Imported Assets in DVDMaestro, which show the movie file length 00:41:27.04, audio file length 00:41:26.20

the audio file is always a bit smaller or a bit bigger than the video when looking at the length at the two.

Even tried to extract the audio to WAV in VirtualDub, and burn the vcd-dvd with ULEAD DVD Workshop instead (with replacement WAV-file instead of the sound in the mpeg) but the very exact sync error keeps appearing.

What am I doing wrong here?!! Isn't it possible to convert the audio from 44,100Hz to 48000Hz without it changing the length of the audio?

The movie sync fine in the beginning, but the more into it you get, the more audio gets out of sync.

Anyone got any ideas?

[DJRumpy]

It's doubtful the problem lies with SSRC. The more likely problem is with your source file. If your audio has errors in it, or even your video, converting them will simply leave those bad frames out, shortening the length of the resulting file, and introducing sync problems.

You can examine an AVI for errors in VirtualDub, but it may not detect all errors. BeSweet will report errors when trans-encoding audio as well.

You can use more advanced editors, like Gold Wave, which will let you scale our audio precisely to the length of your video. I've never used it, but many here will swear by it.

Me, I just accept that sometimes your source is bad, and move on...

[wazp]

well, almost all of my 26 mpeg's generate this sync issue, but yes, it might be the original file that is corrupt. although I highly doubt it...

I will check out Gold Wave, thnx for the tip!

[DJRumpy]

Out of curiousity, what is your source audio format, and what is your source, and sourc fps?

I might suggest you work on the sound seperately from the video. I don't know what your source is, but I'm assuming AVI at this point. If your extracing it via VirtualDub, then you should scan it for errors.

If your source file is in the wrong framerate, then the problem could be due to a change in framerate. Is the lost sync issue very noticable (minutes), or very minor (seconds)?

I use SSRC directly via the BeSweet GUI. Extract my audio from the source. I don't join it back with the video, until I have the finished M2V file. Can you give a quick flow of how you get from Source to DVD?

[wazp]

The source is MPEG-1 352x240 29,97fps CBR 1150kbps, and the audio is Layer-2 44100Hz 192kpbs. the audio is embedded in the source.

Therefore I thought I would be able to follow the VCD to DVD guide ( http://www.vcdhelp.com/vcddvdr.htm ), but when I do that the audio gets out of sync. After that I tried to save the audio as WAV 48000hz in VirtualDub (just extract the audio and do nothing with the video), but with this method I still get the same sync problem. This was a longshot though, since VirtualDub doesn't handle mpeg-files to well...

[DJRumpy]

If your just trying to convert the VCD to DVD, demultiplex the audio/video using MPEG TOOLS in TMPGenc.

Load the file into BeSweetGUI (see the Tools section on the left). Make sure you also have SSRC installed, and configured in the GUI as well.

Convert the audio file to WAV (required for SSRC) using BeSweet
Convert the file sample rate to 48000 with SSRC
Convert the file to MP2 with BeSweet

Author in your favorite DVD program, or multiplex back into your M2V.