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View Full Version : HELP: AAC is mixed to wrong speakers


SirLamer
14th May 2006, 22:12
Hello,

I am trying to work with the AAC audio codec. I am trying to encode 5.1 AAC audio to compliment an MPEG-4 video track (x264, although this is not really important.) The problem is that when I play back the 5.1 AAC, something happens where the audio is all mixed to the wrong speakers. The front right speaker bears most of the sound, as though it were the center speaker. The other speakers still play audio, but it is very quiet usually, as they generally only play the ambient sound effects (including the center speaker, which of course the dialogue should come from). I cannot discern what channels ultimately ends up being fed to the other speakers and where.

One problem is that I cannot tell if this is occuring during the encoding process or if my computer is messing up while playing back a perfectly fine 5.1 audio track.

Important information for the encoding process:
- Using StaxRip
- Using StaxRip built-in "HE 5.1 AAC" variable bitrate profile, which makes use of the Nero DLL.
- Muxing with an x264 video stream
- Have tried both .mp4 and .mkv containers (but not yet AVI)
- Have tried encoding the audio without any video using BeLight GUI, but the same effect occurs

Important information regarding playback hardware:
- Computer: Dell Inspiron 9300 notebook
- Sound card: Audigy 2 ZS notebook card (peripheral add-on which fits in the PCMCIA slot)
- Have tried playback using both Nero Audio Decoder and ffdshow codec package (activity manipulated using mmview and confirmed using both GSpot and feedback within Windows Media Player)
- Have tried playback in Winamp 5 and Windows Media Player
- Speaker setup: 5.1 audio system, although usually I instruct my soundcard to turn off the center speaker and mix to the 2 front satellites because I have no place on which to place the speaker (for 4.1 playback). I have tried AAC playback with the center speaker both on and off. This should not affect anything, though.

I am hoping someone has some experience with this and can provide some advice. Thank you for your time spent considering my request for help!

shon3i
15th May 2006, 11:26
Using StaxRip built-in "HE 5.1 AAC" variable bitrate profile, which makes use of the Nero DLL.
This is the problem because you using old Nero encoder which have this problems with channel order. If StaxRip not support this new encoder and i believe that support it, then you maybe download lastet version and update. Aslo i think that StaxRip support coding tecnologies AAC which good for that job.

stax76
15th May 2006, 12:41
The only solution I know that don't require a intermediate file for the new Nero CLI encoder is MeGUI and that is not a CLI application which would be required by StaxRip. If nobody comes up with a CLI app I have to code it myself which should not be too hard since dimzon wrote the code already.

SirLamer
15th May 2006, 22:30
Indeed, I am using the Nero DLL that showed up in a patch at some point for Nero 6.

Thank you both for your feedback, and thank you for considering ammending StaxRip. It is an excellent GUI, and I love how it manages to make encoding so easy yet at the same time it is incredibly flexible and customizable. Well done!

I will also try MeGUI, which I downloaded last night but did not have time to try out.