Thanks for your reply.
I don't mean to be complaining about NVE as much as I mean to be describing an issue with the DV-avi files that I "capture" with NVE. I'd love to use NVE for this part of the process, but the resulting avi file isn't working for some of the steps I'd like to take.
I'm curious to know more about the experiment you did. Did you capture Digital Video (DV) format directly from a camcorder (or other DV source) using NVE? That is the situation that I'm in here and I would be even more baffled if NVE was turning the audio into AC3 in this case.
NVE ENCODES to AC3 by default, but I'm not encoding here. I'm simply transferring the DV-avi data from my camcorder to my computer. The audio should be PCM, 2-channel, 48Khz, 16-bit. It does appear, in fact, that the audio in the NVE-captured file is this format but, for some reason, the audio format value is being set to 0xFFFE instead of 0x0001. If it was encoding the audio to AC3 format for some reason, the format value should be 0x2000, I think.
At any rate, I hadn't even realized that there were such things as .avi files with AC3 audio, so I decided to try your solution. I installed an AC3 decompressor on my system and tried loading the file into avisynth again. Same error as before.
The reason that I don't capture directly to mpeg-2 is that I'd like the freedom to run my encoding in 2-pass VBR mode (whether I use NVE to encode or Procoder or Quenc or whatever). I'd also like the freedom to run the avi through filters first. If I capture directly to mpeg-2, I give up those abilities.
In cases where my incoming video is very good and/or my desired output quality is not so high, I think that capturing directly to mpeg-2 and then taking it right through the process in NVE to produce the final DVD would be a great way to go. Unfortunately, my DVD player won't play along with that option, due to an issue described here: http://www.cdrinfo.com/forum/tm.asp?m=100404&mpage=1&key=𘠴
Again, it may sound like I'm bashing NVE. Really, I'm not. I wouldn't spend so many hours trying to figure out how to make it work for me if I didn't want to ultimately make it my tool of choice. If I can just get around some of the issues described in this thread and in the one I linked above, I'd probably be using NVE for everything except maybe the most demanding captures that require extra filtering and long, slow, thorough encoding.