VBR MP3 Sync Errors

[pug306d]

I have a AVI file with a VBR MP3 audio track which I would like to convert to AC3, I am firstly converting to a uncompressed WAV file ready for use with Besweet but the WAV file is always out of sync why?

I have tried:

1)Using Virtualdub and full processing on the audio and PCM compression but the file is out of sync

2)Using Virtual Dub to demux the VBR MP3 audio and then run bespilt to repair the file (the length was report incorrectly) then Musicmatch to convert to a WAV file but still out of sync

This is the info from Gspot about the audio from the file

Bitrate - 157 kb/s (78/ch x 2 ch) VBR LAME3.92
FS - 48000 Hz
Codec - 0x0055(MP3) ID'd as MPEG-1 Layer 3

What is happening and how can I do this? The audio does seem to be more out of sync at the end of file than the start after I remux the WAV files with the AVI to test before i convert it to AC3.

Thanks

[DJ Bobo]

demux audio using VD or AVI2WAV, *rename* to mp3, open it in RazorLame (it's a GUI for Lame), hit decode, you're done, your file is in synch!

[pug306d]

hi thanks for the advice I tried that but the audio is still out of sync.

I demux the audio from the Divx 4.12 video file using Vdubmod and converted it to a wav using the razorlame tool. The original file is has 37 frames that looks corrupt between frames 52993 and 53030(see link) although Vdubmod says that there are no error's in the file?

http://members.lycos.co.uk/pug306dd/32.jpg

after I have converted the VBR MP3 audio from the original file to a WAV and remuxed it the audio loses sync on the above frames and the sync gets worse the further on in the file.

What is happenning and how can I fix it so I have everything in Sync? The original file is in perfect sync all the way through even with the above errors.

Thanks

[DJ Bobo]

You can split your AVI into 2: one AVI from frame 0 to 52993 and another from frame 53030 to the end. Then reunite them. You'll sure loose about 2 seconds, but then your AVI will be in synch at least.