6-ch AAC and Matrix Mixer

[Stranger]

Hi,
I searched this forum without finding anything useful for my trouble so.... New 3d :)

This is the situation: I tried to make a 6ch-AAC from a 6ch-AC3 (in order to make some test with matroska) with BeSweet and bsn (tnx DSPGuru, great job!) both LC and HE.
The resulting mkv file was played using TCMP4.

Then I use MatrixMixer to control sound but....
The C sound came from L and R (!!!)
No, channel order is correct, I used -azid (-oc, l, r, sl, sr, lfe) during encoding but if I modify the matrix using 1 in C - C' and 0 everywhere the C sound came from L and R and not from C.
NO sound come from C anything I do, every matrix I use or so on.
For instance, I tryed the original AC3 with ac3filter using the same preset (3/2+lfe) for my system and using the same test matrix (1 in C-C' and 0 on the other) and the C channel (and any channel) is used correctly.
Even trying "Connect to ac3filter" from the system tab of matrix mixer didn't change anything...
I don't think this error comes from AAC, but I would like to know if everyone else has experienced the same problem I had and if someone has some trick to do the job.
Tnx a lot.
Stranger.

[tiki4]

Which version of Nero did you use for encoding? AFAIK from Nero 6.0.0.15 no channel reordering via azid switches should be necessary. Also I think you should just use -bsn( -6chnew ). Furthermore get a current version of the CoreAAC filter. The one from Rarewares isn't the most current. You can find newer compiles here (http://homepage.ntlworld.com/jfe1205/COREaacDS.zip). Also get version 0.30 of the Matrix-Mixer from Sourceforge. I'm rather sure that'll fix your problems.

tiki4

[Stranger]

I used the DLLs from nero 6.0.0.11 so the switch was needed.
I used -bsn(6chold) in my besweet script. The version of matrix Mixer is the 0.30b taken from sourceforge.
I'm going to try the latest coreAAC dll filter and then I'll post if there's some change.

BTW what difference are there between -bsn(6chold) and -bsn(6chnew)?

Tnx for replying.
Stranger


I tried with the coreaac decoder you indicated (tnx a lot)
Something changed....
Now sound of C channel comes from C + L + R even if I set the matrix with 1 in C-C' and 0 otherwise....
Something better but not solved :(
For instance... I tried both aac-LC and aac-HE (the second is seen from CoreAAC as 6ch AAC-LC 48000 -> 48000 as in past version)
Other ideas?

[tiki4]

Well, I re-read that other thread in the meantime. There seems to be an issue with the dll's from 6.0.0.19, but I didn't understand what was meant with 'plays slow'? Anyway, as far as I understood the posts of DSPGuru, the channelordering of the bsn.dll plugin is controlled by -6chnew or -6chold, so it seems to me for Nero <= 6.0.0.11 you just need to set '-6chold' and for Nero >= 6.0.0.15 the other switch (or vice versa). I have to try that myself, but I don't have the time right new, maybe you can find out.

Apart from that I don't think I can help you any further, but why do you want to use Matrix-Mixer on a 6 channel file. I thought that the filter is just for up-mixing from 2ch -> 6ch. Well, again I have to try that myself. My advice is to first figure out the right channel mapping without Matrix-Mixer and then to do further experiments.

tiki4

P.S.: Damn, I couldn't enter the forums for some hours now.

[Stranger]

Originally posted by tiki4

...but why do you want to use Matrix-Mixer on a 6 channel file. I thought that the filter is just for up-mixing from 2ch -> 6ch. Well, again I have to try that myself. My advice is to first figure out the right channel mapping without Matrix-Mixer and then to do further experiments.

Well, you're right.
I tried to use MatrixMixer in order to test the channel distribution.
I knew about channel mapping bug of my version of nero (6.0.0.11) and would like to know if my tests were correct.
Using it to test correct channel mapping I went to this new trouble (and maybe I never saw it without trying matrix mixer for other things....)
The bad things is that even without using matrix mixer I clearly ear the central channel to C + L + R and this is becoming so boring....
I presented a bug report to the author on source forge, but now really I don't know clearly if this is a problem of the coreAAC (changed something installing latest coreAAC ds you give me 3 post ago) if it is a problem of the dll used to encode or if it is a problem of matrix mixer.

Have you some idea of HOW can i test the AAC to see if the channel are REALLY in the right order or if something happened changing order or distribution of channel?

Tnx in advice.
Stranger.

[Atamido]

Originally posted by Stranger
Have you some idea of HOW can i test the AAC to see if the channel are REALLY in the right order or if something happened changing order or distribution of channel? Get one of those test sounds that plays on each speaker one at a time. "Left, center, right, left surround, right surround, LFE."

[tiki4]

Well,

in order to get a feeling for that stuff, I tried to encode a file myself yesterday. Somehow I needed some time to figure out how to configure the AAC encoder and I found out you have to pass -bsn( -config ) or something like that to BeSweet. My Nero is 6.0.0.19 and I didn't find a problem so far. I'll check for channel coupling today.


tiki4

[DSPguru]

Originally posted by tiki4
Somehow I needed some time to figure out how to configure the AAC encoder and I found out you have to pass -bsn( -config ) or something like that to BeSweetcool! i haven't mentioned that switch yet, but you found it yourself :cool: .

[tiki4]

:D

(Long time *NIX user.)

[Eric B]

Is it possible to downmix the AAC 5.1 soundtrack to e.g. 4.1 kit ?
With AC3, it works great with AC3Filter or MatrixMixer, but what about AAC ? Is the sound quality always good ?

[tiki4]

Do you want to encode to a 4.1 AAC file or are you thinking of downmixing to 4.1 at playback time. The second one could also be possible with MatrixMixer (I didn't try that), otherwise you can try the custom channel mapping in Media Player Classic by Gabest.

tiki4