ffmpeg channel designation for Dolby Atmos 11.1.4

[rudolffischer]

I have quite a few SACDs by MDG (Dabringhaus & Grimm) and divox that are recorded in 2+2+2 format. See these two audaud articles for details:
https://www.audaud.com/first-special-feature-on-222-multichannel-discs/
https://www.audaud.com/aurophonie-and-222/
2+2+2 are distributed on SACD and the channels are mapped as follows:

L => L
R => R
C => L front height
LFE => R front height
L surround => L surround
R surround => R surround

Obviously it is not ideal to have the L and R front height channels coming out of the center and subwoofer speakers (although the mix is done in such a way that the 'straight' reproduction is not catastrophic). So far I have played these recordings by converting the mch dsf files to pcm and keeping only the L, R, L surround and R surround channels. I simply left out the center and subwoofer information using ffmpeg's pan filter.

After my first steps with channel mapping using ffmpeg I would like to create a pcm file in 11.1.4 atmos mapping that populates the six channels with the correct placements using the pan functions. This will allow my Onkyo PR SC5507 (which can to front heights) to correctly map the height channels into the 4.0 speaker setup that I have. Also I would like to take the 11.1.4 file to a friend's atmos setup to get an idea what 2+2+2 is actually meant to sound like.

The missing link in this project is the 11.1.4 channel designations that ffmpeg uses. I have found documentation on the c0 c1 c2 c3 c4 c5 nomenclature for 5.1 setups, but nothing on 11.1.4.

[Selur]

I don't think ffmpeg has an 11.x mapping.

NAME           DESCRIPTION
FL             front left
FR             front right
FC             front center
LFE            low frequency
BL             back left
BR             back right
FLC            front left-of-center
FRC            front right-of-center
BC             back center
SL             side left
SR             side right
TC             top center
TFL            top front left
TFC            top front center
TFR            top front right
TBL            top back left
TBC            top back center
TBR            top back right
DL             downmix left
DR             downmix right
WL             wide left
WR             wide right
SDL            surround direct left
SDR            surround direct right
LFE2           low frequency 2
TSL            top side left
TSR            top side right
BFC            bottom front center
BFL            bottom front left
BFR            bottom front right

Standard channel layouts:
NAME           DECOMPOSITION
mono           FC
stereo         FL+FR
2.1            FL+FR+LFE
3.0            FL+FR+FC
3.0(back)      FL+FR+BC
4.0            FL+FR+FC+BC
quad           FL+FR+BL+BR
quad(side)     FL+FR+SL+SR
3.1            FL+FR+FC+LFE
5.0            FL+FR+FC+BL+BR
5.0(side)      FL+FR+FC+SL+SR
4.1            FL+FR+FC+LFE+BC
5.1            FL+FR+FC+LFE+BL+BR
5.1(side)      FL+FR+FC+LFE+SL+SR
6.0            FL+FR+FC+BC+SL+SR
6.0(front)     FL+FR+FLC+FRC+SL+SR
3.1.2          FL+FR+FC+LFE+TFL+TFR
hexagonal      FL+FR+FC+BL+BR+BC
6.1            FL+FR+FC+LFE+BC+SL+SR
6.1(back)      FL+FR+FC+LFE+BL+BR+BC
6.1(front)     FL+FR+LFE+FLC+FRC+SL+SR
7.0            FL+FR+FC+BL+BR+SL+SR
7.0(front)     FL+FR+FC+FLC+FRC+SL+SR
7.1            FL+FR+FC+LFE+BL+BR+SL+SR
7.1(wide)      FL+FR+FC+LFE+BL+BR+FLC+FRC
7.1(wide-side) FL+FR+FC+LFE+FLC+FRC+SL+SR
5.1.2          FL+FR+FC+LFE+BL+BR+TFL+TFR
octagonal      FL+FR+FC+BL+BR+BC+SL+SR
cube           FL+FR+BL+BR+TFL+TFR+TBL+TBR
5.1.4          FL+FR+FC+LFE+BL+BR+TFL+TFR+TBL+TBR
7.1.2          FL+FR+FC+LFE+BL+BR+SL+SR+TFL+TFR
7.1.4          FL+FR+FC+LFE+BL+BR+SL+SR+TFL+TFR+TBL+TBR
7.2.3          FL+FR+FC+LFE+BL+BR+SL+SR+TFL+TFR+TBC+LFE2
9.1.4          FL+FR+FC+LFE+BL+BR+FLC+FRC+SL+SR+TFL+TFR+TBL+TBR
hexadecagonal  FL+FR+FC+BL+BR+BC+SL+SR+TFL+TFC+TFR+TBL+TBC+TBR+WL+WR
downmix        DL+DR
22.2           FL+FR+FC+LFE+BL+BR+FLC+FRC+BC+SL+SR+TC+TFL+TFC+TFR+TBL+TBC+TBR+LFE2+TSL+TSR+BFC+BFL+BFR

source: 'ffmpeg -layouts'
I suspect it's using 'hexadecagonal' for 11.1.4

Cu Selur

[rudolffischer]

Thanks, Selur
It looks like MDG's 2+2+2 is simply 5.1.2 (in ffmpeg terms) with FC and LFE empty.
5.1.2 FL+FR+FC+LFE+BL+BR+TFL+TFR

Would the channel names map to channel numbers as follows?
FL FR FC LFE BL BR TFL TFR
c0 c1 c2 c3 c4 c5 c6 c7
?

[Selur]

Yes, looks correct to me.

[Luke M]

What are you using to do the Atmos encode?

[rudolffischer]

I am not encoding to Dolby Atmos. I am working with multichannel FLAC files.