[MEncoder-users] Does MEncoder has issues with AAC audio encoding?

[Grozdan Nikolov]

Hi,

I have a small problem regarding AAC encoding with MEncoder. I've recently 
encoded a few DVDs to H.264 video with AAC audio (4 channels) and in each of 
my encoded files the audio has distortions in it but only in the background 
music - voices and sound which comes from the center is just fine. 

I then tried to use only 2 channels for AAC, but still I get the same effect 
on both of the encodes. No matter which value I change (bitrate, mpeg 
version, etc) I still get these distortions. When doing a test run on these 
DVDs and encoding the audio to AC3 (one time with 2 channels, the other with 
4 channels) or MP3, the sound is perfect - no distortions at all. It seems 
that only AAC is producing these distortions. I then dumped a minute of audio 
from one of the DVD to WAV and encoded it with FAAC - there are no 
distortions when doing this, so I guess MEncoder has some issues...

The MEncoder AAC command line I use is as follows

-oac faac -faacopts mpeg=4:br=190 -channels 4

Thanks in advance

Regards, GN