Encode an Xvid with AC3 in an MP4 container.

[Shibblet]

I need to use the Xvid codec, mux in AC3 audio, and put it into an MP4 container to allow for chaptering.

I'd love to use VirtualDub MOD, but it doesn't output to MP4. What can I do?
(Please no arguments about how one container is better than another, or one codec is better, this is what I need to accomplish.)

[guns1inger]

I am not sure that the mp4 container officially supports AC3. If you already have a file with AC3 audio you could try Xvid4PSP. Select the MP4 container, select Xvid for Video, and Copy for Audio, and see what you get.

[jman98]

guns1inger is quite correct - the MP4 container does not support AC3 audio. You have to use AAC, Apple Lossless, MPEG audio (including MP3 and MP2) or some weird, little used formats that I don't remember. DTS and AC3 are not supported. What this means in practical terms is that you may not be able to find anything that can put AC3 audio in the container or if you do somehow create it, it may not play back correctly. His suggestion to try Xvid4PSP is probably your best chance to do this, if it even can be done.

[Squash]

AC3 in mp4 was added to the mp4 spec last month:
http://forum.doom9.org/showthread.php?p=1173576#post1173576

I don't know if Xvid4PSP's been updated to support it yet or not, but a test version 0.9.3 of MP4Muxer with ac3 support is available but not yet released. You may be able to get it by PMing Crypto:
http://forum.doom9.org/showthread.php?p=1187836#post1187836

[guns1inger]

The latest Xvid4PSP (installed today) doesn't support encoding to AC3 when using mp4 as an output container. I don't know if it will mux AC3 using copy mode if your source already has AC3 audio. I suspect that it probably won't, and that the underlying applications used by Xvid2PSP don't support it yet either.