Dolby Atmos for music

I’ve got some flac files which are atmos-encoded, but I’m only getting 7.1 audio through Vero. My avr is capable of Atmos decoding, is there any settings on Vero which would support this?

Currently got channels as 7.1, config as optimised, & audio passthrough enabled.


Maximum no. of audio channels for a FLAC file is 8 (i.e. 7.1)

Some ATMOS streams have 5.1 and 7.1 audio anyway, so nothing would be lost in converting to FLACs leaving the AVR to decide how to mix audio for channels beyond that.

If you want more channels then I’d suggest using the MKA (audio version of MKV) file format which will retain the original ATMOS stream, that your AVR can then decode as it is configured/wishes.

To obtain an MKA you will need to rip a ATMOS (audio) blu ray (decrypt) with MakeMKV. The audio stream can then be extracted using MKVToolNix. You can always check the media content of a audio/video file using ‘MediaInfo’

There’s probably more to be said on this, particularly in respect of streaming services and the way in which ATMOS assigns audio to physical audio channels in different systems with varying numbers of channels.

If you give the AVR the source ATMOS stream (rather than FLACs) that would be the best way to render those, with the settings (in particular ‘passthru’) you mention.

Thanks Chris - that’s useful info. My understanding is that the Atmos info is not discrete channels, but embedded in the 5.1 or 7.1 existing channels, as metadata. This is then “interpreted” by the receiver, & used as such.
Just wondering whether it’s the Vero device which is not able to pass it through in a format which the AVR cannot decode, or are there other factors to consider?
Sorry for the qtns, it’s a whole new ball-game for me!

As far as I know the Vero 4K+ is able to passthrough all audio streams.

There was a problem with Dolby Digital Plus - EAC3 audio recently, which has been fixed in a recent ‘staging release’, and will probably be in the next stable release. This scenario might be a problem for you, if you have a stable release installed.

** Enable all passthrough options in your audio settings and set the audio to 7.1

This Audio How To might help as well.

Can you post mediainfo for this file your playing with to eliminate any ambiguity? If this file does have Atmos then I believe you will need to both have passthrough enabled for TrueHD and also be playing the file with videoplayer which I don’t think it will be by default. You may also want to spend some time reading through this thread…

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Hi - thanks for responding, can you tell me how / where I get mediainfo data from please?


edit: Is this it?

Complete name                            : 01. Drive.flac
Format                                   : FLAC
Format/Info                              : Free Lossless Audio Codec
File size                                : 123 MiB
Duration                                 : 4 min 31 s
Overall bit rate mode                    : Variable
Overall bit rate                         : 3 804 kb/s
Album                                    : Automatic for the People (25th Anniversary BluRay)
Track name                               : Drive
Track name/Position                      : 1
Performer                                : R.E.M.
Genre                                    : rock
Recorded date                            : 1992
Writing application                      : Lavf56.40.101
Comment                                  : 24-bit FLAC 48kHz 7.1 Channels

Format                                   : FLAC
Format/Info                              : Free Lossless Audio Codec
Duration                                 : 4 min 31 s
Bit rate mode                            : Variable
Bit rate                                 : 3 804 kb/s
Channel(s)                               : 8 channels
Channel layout                           : L R C LFE Lb Rb Ls Rs
Sampling rate                            : 48.0 kHz
Bit depth                                : 24 bits
Compression mode                         : Lossless
Stream size                              : 123 MiB (100%) / 123 MiB (100%)
Writing library                          : Lavf56.40.101
MD5 of the unencoded content             : B1B8426A7CC55DA6E6A18A85ADB727D4

Yes. I had embedded a hyperlink in my post to a site which spits out the details. You can also download a “mediainfo” application on a PC to view details of your A/V files. As you can see what you have is a 7.1 channel flac file so there is no Atmos encoding.

Apologies, I understood it contained embedded atmos, here’s the ripping info:

24-bit 48kHz 7.1 channel audio ripped from BluRay using eac3to encoding from TrueHD to FLAC and split with ffmpeg
eac3to: Hide

eac3to v3.34
command line: eac3to.exe "../R.E.M. - Automatic for the People Blu-ray/BDMV/STREAM/00002.m2ts" 2: rem7.flac
M2TS, 1 video track, 2 audio tracks, 0:49:07, 24p /1.001
1: h264/AVC, 1080p24 /1.001 (16:9)
2: TrueHD/AC3 (Atmos), 7.1 channels, 48kHz
(embedded: AC3 EX, 5.1 channels, 640kbps, 48kHz)
3: RAW/PCM, 2.0 channels, 24 bits, 96kHz
[a02] Extracting audio track number 2...
[a02] Extracting TrueHD stream...
[a02] Decoding with libav/ffmpeg...
[a02] Encoding FLAC with libFlac...
[a02] Creating file "rem7.flac"...
[a02] Original audio track, L+BL+BR+SL: max 24 bits, average 20 bits.
[a02] Original audio track, R+C: constant bit depth of 21 bits.
[a02] Original audio track, LFE+SR: constant bit depth of 20 bits.
Video track 1 contains 70656 frames.
eac3to processing took 5 minutes, 6 seconds.

or does this just signify the source was TrueHD & the output has been converted to"plain" 7.1, ie no Atmos?

To get Atmos you need the audio in the same format as it is on a regular movie.

For example, ‘mkvtoolnix’ (not Mkvmerge as I said previousy) it is possible to select specific audio/video/subtitle streams and render the selection to a file (MKV or MKA).

If you render just the TrueHD as in this example of my Dune blu-ray (ripped with MakeMKV) you’ll get an MKA file which will have original ATMOS (with meta data) stream and not a discrete 7.1 FLAC.

So you would need to rip your REM Blu-Ray with MakeMKV to a MKV file, load the MKV into MKVToolNix and then select/render the audio part to an MKA file. The MKA can then be ‘played’ (as music) by the Vero.

However, as I recall there were some issues with the Vero not handing MKA files properly, with respect to the ‘time’ field during playback, which I describe in this post [TESTING] Kodi v19 builds for Vero 4K / 4K + - #659 by thechrisgregory

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Thanks guys - learning all the time. So on a more generic level, I’m trying to establish if the flac format can carry Atmos (as embedded).
AFAIK, it seems that you can get Auro-3D layer in flac files, but not sure about Atmos:

I’ll keep digging :slight_smile:

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Atmos is a proprietary format that has to get decoded. The only way it works is for a player to send this file as is to something that can decode and process it. Flac is a format that just compresses standard audio streams in such a way that they can be decompressed back to what they originally were. Auro-3D is a format that encodes (hides) extra channels in a standard audio stream (Like Dolby Pro Logic does) so there isn’t an issue using flac with that file format.

Flac != Atmos.
What you have been doing is converting the atmos into 7.1 channel flac (which is effectively just a lossless compressed PCM.

If you want to play the actual ATMOS (with all the spacial positioning info), you will need to extract as mkv/mka as suggested earlier (that is a container which can handle many types of codecs), and have it play via pass-through to an Atmos receiver.

Note that getting the metadata is a bit trickier for mka. You will need to create a .cue file for kodi to parse the metadata from.

I’d note that if you have a BDA with interesting graphics while the song plays (Rush did that for some of their BDAs for example) you can add mkv as an additional audio type (via advancedsettings.xml), And leave the ripped songs as mkv, and index them into your music library (via a .cue file ) and then kodi will actually play it with the video player, rather than the audio player when you play it.

Thanks guys, & Randall, that’s really useful info re advancedsettings :+1:

Hi Guys, the easiest way to preserve the original Atmos audio encoding is using the .m4a fileformat which can also handle mp3tags like flac. The bitstream will be encoded by the AVR without loosing any channel info. Music Media Helper is a great tool to convert atmos audio tracks into .m4a :slight_smile:

Hi - Ok, I’m now using the Hans Zimmer Live In Prague, have created a single mkv file, & trying to create individual audio tracks, with mkvtoolnix, selecting the TrueHD audio & chapters.
Used split Before Chapters, & all, & it’s created 41 files, however each file seems to contain 2 tracks if I look in foobar.
Any ideas why I get 2 songs per file?

Skip mkvtoolnix and use music media helper directly on your mkv file. Select the atmos soundtrack and convert it to m4a. All should be fine then.

Thanks - yes, that’s what I’ve been doing - MMH seems to fit the job perfectly!

Great! Enjoy. Easy done, and you have pure untouched atmos bitstream in the m4a file.

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