Steve wrote:
> There is a standardized sequence for channel mapping in
> cinema/home-theater sound systems, which is simultaneously codified by
> ANSI, CEA/CEDIA, and the ISO. Though all of those standards documents
> are behind paywalls, this Wikipedia page is correct:
> [ http://en.wikipedia.org/wiki/Surround_sound#Channel_identification ]
>
> 0:L, 1:R, 2:C, 3:LFE, 4:Ls, 5:Rs, 6:Lrs, 7:Rrs
That is the SMPTE/ITU/Dolby 5.1 track layout plus two.
In a paper on their web site,
http://www.dolby.com/us/en/technologies/dolby-surround-7-1-for-theater-tech=
-paper.pdf
Dolby uses this layout for distribution:
L, R, C, Ls, Rs, LFE, Bsl, Bsr (page 5).
DTS 5.1 uses a different layout:
L, R, Ls, Rs, C, LFE
I have been using the DTS layout because the four channels I record come fi=
rst.
According to the Pro Tools 11 Reference Guide, HD-DVD and Blu-Ray systems u=
se the following 7.1 layout:
L, C, R, Lss, Rss, Lsr, Rsr, LFE
But this is a distribution format, not necessarily the layout used in produ=
ction.
Understand that the layout of the console faders and multichannel file trac=
ks is independent of the speaker positions in the room, which don't change =
except by the addition of more channels over the years.
The layout in a particular studio may be dictated by the least-flexible com=
ponent in the signal chain, for example if the console has surround built-i=
n with only one layout.
The problem with distributing nature sounds in surround is how are people g=
oing to play them back. When I set up my studio for surround a decade ago m=
y plan was to make DVDs with surround audio. But DVDs have to have a pictur=
e. I thought I would just have track titles on the screen or slides from th=
e location. But then I discovered that computer image pixels are square and=
DVD video pixels are rectangular, requiring a pre-distortion process for t=
he images. The whole process of producing menus and images seemed like too =
much and I lost my enthusiasm.
Fraunhofer people at trade shows have encouraged me to encode surround audi=
o tracks with their multichannel AAC encoders. They said that computers wit=
h surround sound cards will play that. I know many young people are using t=
heir computers as their main media playback, but how many have surround spe=
akers set up? Only gamers and serious movie fans, I would guess.
There's a company AIX Records that sells 3D videos of music sessions with s=
urround sound to a high-end market. Inspired by that possibility, I revised=
my studio in 2014 to handle 96K audio and I've started doing field recordi=
ng in 96K. Hey, if I can sell my recordings to audiophiles it will be worth=
it. There are bats and insects up there, so if the mics can do it, it's sc=
ientifically helpful to record wider bandwidth than humans can hear.
I keep recording in surround because I love to listen to it. Some day there=
will be a distribution channel.
-Dan
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