5.1 to 6.1 CH Conversion / VST Plugin ? [Archive]

ACrowley

27th October 2007, 15:55

Hello

I know a few Methods to upmix 2 Ch into 5.1 or 6.1

But i want convert 5.1 to 6.1 to encode to 6.1 Formats like DD EX or DTS ES 6.1

Is it possible to create a extra BC Channel with some VST Plugins etc from 5.1 Ch Audio?

greets

Elektra999

27th October 2007, 19:59

Yea, the VST Plug-in LRtoMS (http://www.uk-music.de/toolseng.html)

convert the stereo:

- channel Left in vocies
- channel right in other effects

Note: It will extract the image of the center channel (SC), of the channels SL and SR.

1 - Work in Sony Sound Forge 9, Adobe Audition, Cubase, Nuendo, etc..

2 - Copy of audio original (multichannel 5,1) channels SL y SR in stereo

Example in Sony Sound Forge 9

http://img98.imageshack.us/img98/1170/dibujoen4.jpg

3 - Add VST Plug-ins, LRtoMS and Limite Peaks, because but it will distorsion.

4 - Process.... the channel Left it is channel Surround Back :) Matrix

Elektra999

27th October 2007, 20:30

For 6.1 Channel Discrete, SRS Circle Surround II (http://srslabs.com/partners/paprod/susf_csvst.asp)

ACrowley

27th October 2007, 21:15

For 6.1 Channel Discrete, SRS Circle Surround II (http://srslabs.com/partners/paprod/susf_csvst.asp)

yes, my Target is to upmix a discrete channel to get 7 mono waves.
So, can you give me an Example how to create a new discrete Back Center Channel with SRS Circle Surround Pro, please ?

Elektra999

28th October 2007, 18:08

I believe that the discreet channel can be obtained this way;

- Channels SL and SR in stereo

- In Plogue Bidule, Add Audio Files Player - SRS Circle Surround II - Audio File Recorder

http://img249.imageshack.us/img249/4217/dibujoho5.jpg

ACrowley

30th October 2007, 12:08

For my Test i compared the "real" SC Channel from a discrete 6.1 Track with the new upmixed SC Channel out of SR/SL from Plogue Bidule/ SRS Circle Surr.VST

1 upmixed Back Center Channel out of SL/SR (dts es 6.1)
2 "Real" Back Center Channel from 6.1 dts es discrete

http://img99.imageshack.us/img99/9520/sshot4qj4.th.png (http://img99.imageshack.us/my.php?image=sshot4qj4.png)

You can see in the First Part from the upmix is a Sound which is not present in the original BC .

Mh... i used the default SRS Circle Surround Settings, i think it was wrong for this Project.
Can you tell me which Settings i should use to upmix a discrete BC Chanel from SL/SR ?

But : You show me above i have to connect the 4th Channel from SRS Plugin to the Audio Recorder ?
Strange, the Channel for Surround Center is the 5th (in Channelmapping from SRS Plugin) ?

Elektra999

1st November 2007, 17:06

SRS Circle II, it is to do the audio conversion stereo to 5.1/6.1 Surround, then if that makes one good mixes.
I thought this idea about Plogue Bidule, with SRS Circle II, but if there are mistakes, not to be said to him any more...

The order of the channels in SRS Circle II:

FL - FR - CENTER - SC - SL - SR - LFE
THE CHANNEL 4 of SRS Circle II, it is the channel SC.

An idea happens to me, but not ... if it will have good proved, and I do not try to make him lose any more time.

Sorry, Acrowley :)

Elektra999

1st November 2007, 17:34

I think, that, to do the discreet channel, which would have, codify the whole audio:

Add WAV 6 of channels in Audio File player 6 channels

FL - FR - CENTER - LFE - SL - SR

http://img442.imageshack.us/img442/5290/01fg6.jpg

To spend it for the SRS Encoder

FL - FR - CENTER - SL - SR - LFE

http://img208.imageshack.us/img208/6964/02pb7.jpg

and SRS Circle II (Decoder)

http://img260.imageshack.us/img260/8486/03fe5.jpg

Audio File Recorder 8 channels

OUT

FL - FR - CENTER - LFE - SL - SR - SC

Not ... if good results will be obtained?
Luck

Arite

1st November 2007, 18:57

I take it you want to simply reproduce the "SC" channel, only having it so that it is not just a simple matrixed version of the SL and SR?

I presume the ideal method would be to take only what is similar in both the SL and SR, and not just averaging them out [(SL+SR)/2]? I don't know if that is what SRS Encoder is doing, but it looks like both audio from the surround left and surround right channels are retained, which may not be wanted if they are exclusive to that channel.

If you invert one of the channels and merge them together then you will end up with a track which just contains the differences between the two channels.

What you could then do is merge that "difference" track with the normal "(SL+SR)/2" track, and you should end up with just the similarities in the two audio tracks (this can all be done in Audacity). Not sure it that is excatly right though.

Cheers, Arite.

Elektra999

1st November 2007, 23:06

The channel SC Matrix, it is a mixing of 2 channels SL and SR

I don't Know....the discrete channel SC, but, I believe that it is possible to do, as I made clear more above.

ACrowley

2nd November 2007, 12:14

yes..as i say i compared the "real" original SC from the dts es discrete 6.1 with the upmixed SC out of SL and SR.

You can see above that the upmixed SC has Sound which are not present in the original SC
Ofcourse the Sound is present in SL and SR

So the original SC is different (sure its a Studio Mix)

Ah, Elektra, youre talking about SRS Circle Surround II.. are you sure its vII (=v2)
I know only v1 of the VST Plugin ,dont know if theres v2.
Only for Pro Tools is a v2.0 as Plugin

Elektra999

2nd November 2007, 18:40

Ah, Elektra, youre talking about SRS Circle Surround II.. are you sure its vII (=v2)
I know only v1 of the VST Plugin ,dont know if theres v2.
Only for Pro Tools is a v2.0 as Plugin

Sorry, You have reason, VST's version SRS Circle is 1.0.1.
Thank you for the rectification :thanks:

ACrowley

3rd November 2007, 18:01

Sorry, You have reason, VST's version SRS Circle is 1.0.1.
Thank you for the rectification :thanks:

1.0.2 :)

Skelsgard

3rd November 2007, 20:01

@ ACrowly
Dolby EX is just an upmixing algorithm, so doing 5.1->6.1 upmixing to encode as AC3 again will be pointless, just use a DD-EX decoder in forced mode.
If you want to encode to DTS-ES Discrete 6.1, then it makes sense.

If you have a AC3 5.1, and the SC info on the SL/SR channels, then just use Center Cut GUI to extract the "center" information from the surround channels, which will be the SC.
Just decode the whole AC3, get SL and SR, combine them into a 2ch WAV file, and load it into Center Cut GUI.
That should do the trick.
You'll get you SC channel matrix-upmixed from SL/SR.

@ Elektra999
The SRS way just makes it worse.
If upmixing x-ch to >x-ch is not clean due to frequencies overlapping, imagine having 5.1, downmixing it to 2-ch, then upmixing it 6.1, then re-encoding to another format (DTS).
Using CS II is not a good option, specially if you have a 5.1 source.

Later

Elektra999

3rd November 2007, 20:29

Hello Skelsgard :)

@ Elektra999
The SRS way just makes it worse.
If upmixing x-ch to >x-ch is not clean due to frequencies overlapping, imagine having 5.1, downmixing it to 2-ch, then upmixing it 6.1, then re-encoding to another format (DTS).
Using CS II is not a good option, specially if you have a 5.1 source.

:thanks: for the reply

Audio 5.1 discrete channels, I believe, that, it is not possible to extract the channel SC, due well.

Another thing ... they are channels Matrix, then if that can extract the center image to him (of the channels SL and SR), with the plug-in LRtoMS (as I explained more above).

¿You have seen the guide? (http://forum.doom9.org/showthread.php?p=1059487#post1059487)

Skelsgard

3rd November 2007, 20:40

Hello Skelsgard :)

:thanks: for the reply

Audio 5.1 discrete channels, I believe, that, it is not possible to extract the channel SC, due well.

Another thing ... they are channels Matrix, then if that can extract the center image to him (of the channels SL and SR), with the plug-in LRtoMS (as I explained more above).

¿You have seen the guide? (http://forum.doom9.org/showthread.php?p=1059487#post1059487)

What up, dude? :cool:
Long time no see (I'm still jealous of your DTS-ES encoder :D)

Yea, if read your first answer, my clarification was about the use of SRS CS II as you stated: "For 6.1 Channel Discrete, SRS Circle Surround II"
But SRS is not Discrete in any way.
It's a matrix decoder-upmixer.

So using LRtoMS or Center Cut GUI for center info extraction from SL and SR will make much better output than CS II downmixing and upmixing.

Later

Elektra999

3rd November 2007, 20:54

He, was thinking, that, the channels of SRS Circle, they were discrete. Because every channel mono, it is heard differently, and because the channel SC (of SRS Circle) cannot be used in the Encoder Dolby Surround EX-, because, the codification is wrong.

The channel SC of SRS Circle Surround, if that
It works well, in the Encoder DTS Pro Series, but, not in the encoder dolby 6.1.

I'm still jealous of your DTS-ES encoder je je :)