+- MinimServer Forum (https://forum.minimserver.com)
+-- Forum: MinimServer (/forumdisplay.php?fid=1)
+--- Forum: General (/forumdisplay.php?fid=2)
+--- Thread: Multi Channel Atmos (/showthread.php?tid=7353)
Multi Channel Atmos - rompolompo - 26-09-2024 04:31
Hi,
I have a Dolby Atmos multi channel mix in flac. There are 8 channels within every file. How does MinimServer calculate the specific Atmos configuration? For example, MinimServer shows this as a 7.1 file. Why not 6.2 or 5.3? Where does it read the info from?
Many thanks!
RE: Multi Channel Atmos - simoncn - 26-09-2024 10:51
The FLAC specification supports the following channel assignments:
1 channel: mono
2 channels: left, right
3 channels: left, right, center
4 channels: front left, front right, back left, back right
5 channels: front left, front right, front center, back/surround left, back/surround right
6 channels: front left, front right, front center, LFE, back/surround left, back/surround right
7 channels: front left, front right, front center, LFE, back center, side left, side right
8 channels: front left, front right, front center, LFE, back left, back right, side left, side right
MinimServer shows these in the #AudioChannels special tag as follows:
1 channel: 1
2 channels: 2
3 channels: 3
4 channels: 4
5 channels: 5
6 channels: 5.1
7 channels: 7
8 channels: 7.1
There is an inconsistency for 7 channels, which should probably be shown as 6.1 because it includes LFE.
Other "nonstandard" channel assignments can be used in audio files and there is an industry standard file tag WAVEFORMATEXTENSIBLE_CHANNEL_MASK to specify these assignments. MinimServer does not currently support this tag but support could be added if needed.
Do your Dolby Atmos files conform to any of the FLAC standard assignments listed above? If not, do they use the WAVEFORMATEXTENSIBLE_CHANNEL_MASK tag to specify the channel assignment?
RE: Multi Channel Atmos - rompolompo - 26-09-2024 16:27
Hi Simon,
So, MinimServer currently maps the channels based on their order? When the file is used by a streamer (umpmdcli / MPD), do they follow that as well or do they use ALSA to map the channels? Also, where can I find information about the tags? The files I have were ripped from a blu-ray player and do not have this vorbis tags. I can upload a sample file if you want.
Thanks!
RE: Multi Channel Atmos - simoncn - 26-09-2024 16:59
MinimServer does not do any mapping of channels. The channel order in the audio file is the order that will be sent to the renderer. If you need to remap to a different order, it should be possible to use MinimStreamer and FFmpeg to do this but setting the right options can be tricky.
To see all tags in your library, you can set the writeAllTags property and do a rescan.
RE: Multi Channel Atmos - rompolompo - 26-09-2024 19:07
Simon,
I am not trying to remap. Just trying to better understand the way it works. These are the tags:
date=1972
label=Parlophone
album=The Rise And Fall Of Ziggy Stardust And The Spiders From Mars (Hi-Res, Atmos Mix, 7.1)
tracknumber=04/11
artist=David Bowie
composer=David Bowie
copyright=Parlophone – 5021732238757
source=Blu-Ray
title=Starman
genre=Rock
RE: Multi Channel Atmos - simoncn - 26-09-2024 23:11
You don't have a WAVEFORMATEXTENSIBLE_CHANNEL_MASK tag, so the channels are mapped as described in post #2.
RE: Multi Channel Atmos - rompolompo - 26-09-2024 23:13
Many thanks!