Re: 5.1 Audio on Encore CS4 - Help Please!

[David Andrews] "I actually have 5 .m2v video files and 5 .ac3 audio files which I have placed one after another on the main timeline. "

That's your problem, right there.

AC3 files have null data blocks at the end of their file structure. When they are added together in a timeline, they will gradually introduce a loss of sync with video.

In order to address this problem, Encore decompresses multiple AC3 files in a timeline to raw audio, and then recompresses these clips into a single AC3 file, which eliminates the problem with a loss of synchronization if otherwise unaddressed.

The problem is of course that Encore's AC3 encoder is Dolby Digital 2.0 only, and this is why your clips are being re-transcoded.

The solution is either to combine the 5.1 AC3 files elsewhere to a single 5.1 AC3 file (sorry, I don't have any specific suggestions, but there may be freeware tools that can do this - start at videohelp.com), or use separate timelines for each video/audio pair.