Video passthrough doesn't work?

[mbourgon]

I just downloaded 9a, and am having problems converting an iMovie/iDVD VOB. Since an iMovie/iDVD-based VOB uses LPCM, I'd like to create a new MPG/VOB, using the original video but compressing the audio (doing this so a PrismIQ will be able to open the file - it can't cope with LPCM).

I choose the DVD hi-bitrate, change the video setting to "Passthrough (ffmpeg)", disable "Author as DVD" (since I just want the VOB), and click encode. I wind up with a file that looks to be about the right size, but I get the following when I try to open it with VLC .6.2:

"main: no suitable decoder module for fourcc `mpg1'."

Any suggestions? ffmpegx is the only tool I've found so far that can deal with the LPCM (since creating a SVCD works - but it takes 10x the length of the original, on a dual G5-2ghz!).

Thanks!

[mbourgon]

*bump* This is on a G5 running Panther, if that helps.