box said:
I'm hoping to share out 2.5 via AVCHD on DL-DVD. Will this be possible by simply de-muxing enough audio tracks to reduce the file size or will a re-encode be necessary?
I think you'd be over the size limit if you stripped out all the audio, so a re-encode would be necessary. If memory serves, AVCHD doesn't handle DTS, so AC3 DD would be your options there.
Why not just use 2.1's AVCHD in this case? It's already compressed and very close to 2.5 in content.