My path to authoring my DVDs goes through several steps. Others I tried did not prove as good, so I always get back to it. As I usually start with a downloaded PAL avi file and I live in an NTSC country, first of all I use Procoder 1.5 to convert from PAL avi onto NTSC MPEG2. Then TMPGENc takes over to do the chapters and VOB files, and as most of the times the result exceeds 4.7GB I use Clone2DVD to do the burn. Sometimes I have to rely on DVDShrink to make the files fit a size up 5.3GB, which Clone2DVD and the media I use will handle well. But recently I am having some problems with dual-language audio "oldies", which Procoder even refuses to load. They are loaded and read by all the player programs I use, like VLC, WMP or RP, so it doesn't seem to be a file problem. Procoder has proven to be the most transparent program to do the PAL to NTSC conversion, as TMPGEnc 3.0 Express did some glitchy and far from transparent conversions. A way around this might be doing a simple AVI to MPEG2 conversion, with no TV system change, picking the dual language option if possible, then do the VOB files and copying them onto a file, then re-capturing them with same program and converting those files onto a PAL MPEG2 big file, which probably Procoder will be able to handle and convert onto NTSC. Now: which is the best program to do that AVI to m2v/wav files, preserving the dual audio channels? If you anyone can suggest a better path of course I am open to try it.
Assuming you're dealing with progressive content (and since you're starting with AVI's I'm guessing you are) you could use DGIndex to demux the video and audio and then encode to MPEG with no standards conversion. After that DGPulldown could be used to add flags that make it play at an NTSC framerate (similar to the way film content is flagged to play at the correct framerate) and author normally with the original audio streams and the new M2V. You can find links for DGIndex and DGPulldown in the Links & Resources sticky at the top of this forum.