I usually render to avi. The renders are large so I found a tip that said to either render the avi or the orignal project in main concept mpeg-2. Video looks good but no sound. Am I missing a codec?
First of all, what are you rendering for? It's good to know the intended use of the output file first so that the most appropriate format can be chosen.
If you rendered the file with one of the DVD Architect templates in order to create a DVD then no audio is normal. You would normally render the audio separately to a .ac3 file.
If you're not making a DVD, may we ask what you are trying to accomplish? Knowing that, we can help you a lot better.
Rendering for the internet. My last movie was 7 minutes at 9GB+. Way too big. Most of my projects are just for my own viewing. Eventually, I'll want to upload something but not at those file sizes.
Lots of folks are using MP4 in a .avi wrapper or .avc for uploads. These are pretty good quality in relatively small file sizes.
For my YouTube uploads I use mpg2. When you select mpg2 there are a number of options available. As mentioned if you accidentally choose a DVD Artechict option it will, by default, not include audio. I would use "DVD NTSC" .. assuming you are in NTSC land, and see if that is OK for you.