[Flac-dev] 2/0, 2/2 3/0, 3/2, 5.1, wxyz

[smoerk]

Josh Coalson wrote:

> --- smoerk <smoerk at gmx.de> wrote:
> 
>>i didn't find anything about tagging flac files as surround files. i 
>>think there should some possibility to tell the player how to play a 
>>multi-channel file (how to map the different channels to the speakers
>>or if there some decode is needed, like for ambisonic files).
> 
> 
> it wouldn't be in the tags, it would be a specific channel
> assignment in the frame header:
> 
> http://flac.sourceforge.net/format.html#frame_header
> 
> there are currently none defined for >2 channels but there could
> be.

i would write a proposal for this, but i don't think 4 bit is enough for
all the different surround formats. for example in a ac3 encoder i can
define any combination of left-right, center, surround and LFE channels.

http://www.soundonsound.com/sos/nov01/images/surroundfig1dolbyblobs.l.gif

there are different channel profiles for 5.1:
L R C LFE Ls Rs (DVD)
L R Ls Rs C LFE
L C R Ls Rs LFE (Film)

then we have ambisonics where we have 1st, 2nd and 3rd order (4, 9 and
16 channels), but then you can also have 2 dimensional ambisonics
without heigt signal, which gives another 3 options, plus different UHJ
encoded variants, etc.

how can we squeeze this in 4 bits?