6.1 to 5.1 EX/ES

[mp3dom]

Hi all!
I need some informations/tools/hint.
I currently have a 6.1 discrete track (7 wave files). I need to convert, in the proper way, the 6.1 discrete track into a 6.1 matrixed track. The final compression would be dts-es matrix. What's the proper way? Is there an 'automatic' way via VST plugins to do so? (I could use SoundForge or Vegas). I know that dts-es could be discrete (so no need to 'downmix' to matrix) but the mixing studio at the moment can't mix in 6.1 so I would like to keep the phantom 6th channel, let the studio mix in '5.1' and then encode enabling the matrixed encoding.
Thanks.

[Midzuki]

From what I've read (and understood) so far,
the well-known routine:

apply -3dB to the back-center channel,
mix it with both Back-Left and Right-Back,
normalize,

should be sufficient
( or at least I hope so :o ).

[mp3dom]

Thanks. I'll try what you've said.
Also, do someone knows the exact mapping of a 6.1 interleaved wave? Is FL/FR/C/LFE/Ls/Rs/Cs ? I've seen that eac3to have the -down6 option to downmix to 5.1, but it doesn't accept 7 waves mono files so I would just like to know how it's expecting the channel mapping for an interleaved wave. Also do the eac3to results needs the 'phase shift' option in the dts encoder? (dts suggest to always enable it for matrixed tracks, but since it's not a native-matrixed tracks...)
Thanks!

[Midzuki]

"Common" :) 6.1 .WAV can be:

FL, FR, FC, LFE, BL, BR, BC,

or

FL, FR, FC, LFE, BC, SL, SR

eac3to's "phase shift" applies to stereo downmixes only.

Besides, the DTS-HD Monster Audio PDF says:

DTS recommends enabling ES Phase Shift for 6.1 ES Discrete encodes.

DTS recommends disabling ES Phase Shift for 6.0 and 6.1 ES Matrix encodes.

ES Phase Shift and ES Pre-Mixed cannot be used simultaneously.

++++++++++++

Selecting ES Phase Shift performs phase shifting of left and right surround channels by +/- 45 degrees prior to the addition of the center surround channel. The ES Phase Shift option can only be selected for stream types other than DTS-HD Master Audio.

[mp3dom]

Thanks, so if I do a 6.1 wave (l/r/c/lfe/ls/rs/cs), pass it to eac3to with -down6 (is eac3to capable of auto-detect the channel mapping?) switch and output 6 mono waves, can I think that this is a correct way to downmix a 6.1 track to 5.1es track? Without adding phase shift or set other flags? Thank you very much!

[Midzuki]

JMHO, but it seems you're trying to make things more complicated than the necessary. :) Sox can easily mix the back-center into the BL and BR channels. Then just feed Surcode with the 4 "old" .WAVs and the 2 "new" ones.
BUT, iirc, the old versions of Surcode cannot "flag" their DTS encodes as 6.0 or 6.1. :confused:

edit:

and eac3to is unable to "call" the encoders made by «DTS, Inc.».

[mp3dom]

The fact is that I want to be sure that all is 100% done in the right/proper way. I don't want to risk to screw something. Probably I'll try the eac3to way, since it's automated. As for encoding, we have the dts-HD MAS, so no problem for flags :)
I'm making just now a test to monitor the output of the 'phantom' CS channel. I'll let you know. Thanks very very much for your quick answers! It was indeed a urgent problem to solve. Really thanks.

For this work I'm using always WAV (w64 as source, and multiple mono waves as output) so there's no problem :)

Edit: All right! Phantom CS works very well, better that what I've expected! Works well with AC3 5.1EX also, and also downmix to 2.0 is not that bad. Thank you again!

[Midzuki]

Edit: All right! Phantom CS works very well, better that what I've expected! Works well with AC3 5.1EX also, and also downmix to 2.0 is not that bad. Thank you again!

This thread contains "too many" :thanks:

:) :p :D

I'm just and only a :helpful:

[ACrowley]

Ok....and when the discrete BC is mixed into BL BR i can simply set the EX Flag in a Dolby Encoder right ?

Is it possible to import 7 mono wavs into a Sony Vegas or Soundforge 6.1 record and encode it to AC3 EX ? Or do i have to mix the BC into BL BR previously for (E)AC3 EX ?

I mean the DTS HD Master Suite can use 7 mono waves to encode DTS ES Matrix, so the encoder itself will mix it into the Matrix

[mp3dom]

Yes, if you've mixed the Cs into Ls and Rs you simply set EX flag.
The Master Audio Suite allows you to import 7 waves and encode dts ES Matrix only for 'dvd' projects (.cpt). If you want to do dts-HD Matrix Master Audio (lossless for BD) you can specify only 6 waves so you already need to mix the Cs into Ls/Rs

[ACrowley]

Yes, if you've mixed the Cs into Ls and Rs you simply set EX flag.
The Master Audio Suite allows you to import 7 waves and encode dts ES Matrix only for 'dvd' projects (.cpt). If you want to do dts-HD Matrix Master Audio (lossless for BD) you can specify only 6 waves so you already need to mix the Cs into Ls/Rs

Ok..and when theres no mixed BC into BL BR but the EX Flag is encoded ? Will there be simply no output from the BC or a "upmix" out of BL BR ?

[tebasuna51]

Then the decoder extract the common part in BL-BR and output to BC (in a 6.1 speaker system)

[ACrowley]

Ok...

And when i have 1 7.1 to 6.1 discrete encode needs i have to mix the BL and BR into BC ,correct ? In Soundforge i can paste/mix the BL and BR togther into one mono Track = new BC for DTS ES Discret encoding

[tebasuna51]

Yes.
Always you mix remember check the peaks to avoid overflow.