AC3 to MP3 Conversion / Synchronisation

[sjdean]

Hi,

I am trying to convert an AC3 file to an MP3 and then multiplex the MP3 back to the original MPEG2 file so I can get a good DivX conversion.

Unfortunately while the MPEG2 file is say, 32 minutes and 10 seconds, the AC3 file is also 32 minutes and 10 seconds, and the converted MP3 is 32 minutes and 10 seconds, when multiplexed, I get the most horrendous sync issue.

I get a gradual time sync issue so that the further you get on through the file, the more out of sync it is.

What am I doing wrong here?

Thanks
Simon

PS Using TMPGENC and BeSweet GUI.

[hech54]

Is the AC3 48khz and the MP3 44.1khz?

[sjdean]

Let me try another conversion. I remember the version of BeSweet I have seems to produce MP2 files that TMPGenc doesn't like. I got a feeling I may have been converting to MP2 then to WAV then to MP2 again. It certainly sounds like this kind of issue.

Any better AC3 converter tools than BeSweet?

[hech54]

I go straight from AC3 to MP3 inside my video conversion software(AviDemux, VirtualDub, or MainConcept).

[olyteddy]

And avoid VBR MP3 profiles.

[manono]

I am trying to convert an AC3 file to an MP3 and then multiplex the MP3 back to the original MPEG2 file so I can get a good DivX conversion.

You didn't answer hech54's question. For some reason converting from 48kHz to 44.1kHz using BeSweet produces audio that gets progressively out of synch. Anyway, why not use AutoGK to do the whole DivX conversion - audio and video - at one time? Just load the original MPG, set it for MP3 with the bitrate you want in the Advanced Settings, and let it take it from there.