AAC 6 channels compression

[Kenshin5]

Im encoding some anime and i figured i should try 5.1 since most of the groups use it, but after a long search i can't get anyware to compress what i want. Can someone tell me of a way to compress an 5.1 aac file from ac3 container. I want the result file to have an extension .aac not .mp4 . Tried some of the guides here getting mp4 files witch is not what i want to mux with matroska, tried headac3he im getting some error:
"AC3 decoding cycle [00:00:06.085] W7: Downmix overflow (1: +0.7dB)
[00:00:07.765] W7: Downmix overflow (1: +0.2dB)
[00:00:07.792] W7: Downmix overflow (1: +0.9dB)"

So someone please tell me a way to compress a decend aac 5.1 audio.

[Nil Einne]

BeSweet is probably best for what you want to do but why don't you just convert the mp4 to aac and be done with it?

It sounds like your doing things wrong with Headache. If you are converting ac3 5.1 to aac 5.1 you should not be downmixing!

BTW, are you encoding a backup or are you encoding some anime you own the copyright of (or is copyright free) for others to use? If you are making a backup, only consider your system. Who cares what the groups use. The question is what do you want and need. If you don't have 5.1 and are unlikely to want it in the future or would be willing to redo your backups then don't do 5.1!

P.S. It doesn't really matter what the extension is. You could easily convince most programs to give either extension or some other extension like ".mine name is kenshin5 and i like the extension aac" or rename ityouself later. What you want is an aac stream not an mp4 stream...

[Kenshin5]

What do i use to convert mp4 to aac, and for Headac3he i guess i should be using the default settings when i load the ac3.

[bond]

What do i use to convert mp4 to aac, and for Headac3he i guess i should be using the default settings when i load the ac3.why do you need a raw .aac stream and not aac-in-mp4?

you can extract streams from .mp4 to raw with mp4box (yamb gui) and mp4creator

[SeeMoreDigital]

What do i use to convert mp4 to aac, and for Headac3he i guess i should be using the default settings when i load the ac3.If you use HeadAC3he, make sure it's v0.24-a13 (15.12.2004).

After inputting your 6Ch AC3 stream and setting the "Destination Format" to AAC, you will need to head over to the "Channel Configuration" window and click on the "6Ch" button.

Then you have to click on the "Options" button and you should now see an "FAAC Configuration" window. Like this: -

http://img386.imageshack.us/img386/1334/headac3he7oy.png

As you can see, there are plenty more options here... But it's probably best to go for "ADTS" for the bit-stream. The other settings are up to you ;)


Cheers