No audio on transcoded video

[evolker]

I'm trying to convert an mpeg4 avi with mp3 audio to an mpeg2 file suitable for burning to DVD. The problem is I keep getting an .m2v file, which of course has no audio. On the audio tab, .AC3 audio is selected and "Encode audio" is *checked*. In the "Save As" box, I've specified an .mpg extension, but I still keep getting a file with .m2v. There is no seperate audio file, such as .aiff, .wav or .mp3. Why can't I get any audio out of this .avi file?

[Case]

Did you wait until it said "Finished"?
The normal behavior with mpeg2enc is that it creates first an .m2v file, then an .ac3 file, then it muxes these two together into an .mpg file.

[evolker]

No, I had no idea that was how it behaved. Other encoders I have worked with muxed audio and video simultaneously. Anyway, I worked around the issue by using ffmpeg instead of mpeg2enc, though it took some futzing around with letterboxing to get the aspect ratio correct. Is there any real difference between the quality of ffmpeg and mpeg2enc output?