Nero AC3 channel mapping

[Robot]

I ran a search, but I didn't find anything specific to this.

Here’s what I’m doing:

1. I’m taking a 5.1 AAC file and opening Nero “Encode Files” in Nero 6.

2. I then convert the AAC file to an AC3 file.

3. Because NERO creates a 41khz AC3 file, I have to re-encode to 48khz with AC3Machine.

The problem I’m having is that when I burn the DVD, the center channel comes out of the left speaker. Nero allows you to place the lineup for the channels, but no matter how I order them, the center is in the wrong place.

Where am I going wrong?

[Skelsgard]

2. I then convert the AAC file to an AC3 file.

3. Because NERO creates a 41khz AC3 file, I have to re-encode to 48khz with AC3Machine.
This redundant re-encoding will cost u quality. Try to use a direct AAC-->AC3 conversion. Or an AAC-->WAV-->AC3.
I also recommend u to use Aften for AC3 encoding.

About the wrong channel output: AAC is mapped as C-L-R-Ls-Rs-LFE, while AC3 is mapped as L-C-R-LFE-Ls-Rs. If whatever tool u use for conversion doesn´t apply the proper remapping, the final output will have the channels shifted.

Ch: . 1 - 2 - 3 - 4 -- 5 -- 6
Aac: C - L - R - Ls - Rs - LFE
Ac3: L - C - R -LFE- Ls - Rs
Wav:L - R - C -LFE- Ls - Rs
If your Ch1 (C) is not mapped to Ch2, your Ch1 (L) in AC3 will played the AAC´s Ch1 (C). Also if u decode to Wav without chanel remapping, Aac´s C would be in L, L in R, R in C, and so on.

[tebasuna51]

If you are lost (http://forum.doom9.org/showthread.php?p=853394#post853394) with BeHappy, and need convert a 5.1 44.1 KHz aac to 5.1 48 KHz ac3, you can use:

1) Faad for aac -> wav
2) WaveWizard for 44.1 -> 48 KHz
3) Aften for wav -> ac3

[Robot]

When I use Nero to convert the AAC to wav, it remaps the channels. There are no options for wav, so I can't do anything about this.

Does anyone now a better AAC to WAV program that will accept AAC and not remap the channels?

Thanks.

[tebasuna51]

I say you FAAD 2 for Win32 2004-07-09 (http://www.rarewares.org/aac.html), the output wav is correct mapped and with WAVE_FORMAT_EXTENSIBLE header (accepted by Aften and WaveWizard).

[Skelsgard]

If u already have the Wav from Nero, u can remap it with Wavewizard.

[Robot]

I'm having trouble finding Wavewizard to DL. Does anyone have a link?

[raquete]

I'm having trouble finding Wavewizard to DL. Does anyone have a link?
download from
http://forum.doom9.org/showthread.php?t=105684
and in "Part 2: Merging or splitting files" of this guide have one good WaveWizard "how to" .