A list of Atmos mixes that require gapless playback

[HomerJAU]

How do I identify individual discs in a multi-disc MKV file? I'm referring to Kraftwerk's 3D The Catalogue, which is split into two discs (4 albums for each disc). It seems the only way I have to do this is to name them "disc 1" and "disc 2". thanks.

EDIT: I think I can split the individual albums using MKVToolNix, but it's probably better to keep two large MKA files (BR Disc 1 and BR Disc 2), and then create a cue sheet that combines both (use the same album title and progressive chapter numbers). I'll give it a try.

For Atmos gapless you’ll need to do your edit since CUE files support minimal tags.

But for ‘normal’ albums with tracks as individual tagged files, Kodi supports splitting albums into discs by adding a unique value to the files’ DiscSubTitle tag. Kodi then splits the album files into ‘discs’ based on that DiscSubTitle value. I will find a couple of screen shots and post here shortly to show what it does.

EDIT: This post shows what Kodi looks like using the ‘DiscSubTitle’ tag:

Three versions of Abbey Road with DiscSubTitle tags: ‘5.1 Mix’, ‘7.1 Mix‘ and ‘Atmos Mix’.

In the Kodi UI a user sees one album ‘Abbey Road’, clicking on that album shows the 3 ‘discs’ in the last screenshot:

https://www.quadraphonicquad.com/fo...-audio-music-videos.22693/page-32#post-566350
If you are brave you could manually add a DiscSubTitle value to the Kodi music database directly for albums created with a CUE file to give you ‘Discs’.

 

[Albert Dagger]

Matroska files (MKV/MKA) use timestamps in milliseconds. Audio CUE files use ‘frame’ (60 per second I think) unit to measure less than 1 second. I suspect this could cause a slight difference if a chapter has a value with > 600 milliseconds in its timestamp milliseconds value. Kodi does store the correct value in milliseconds in its database.

Its also possible the ffmpeg (used by Kodi) attempts to find the next keyframe in the file from the exact timestamp provided, I don’t know…

Also, I‘ve also thought actual chapter times are often incorrect on BD discs.

I've compared the chapter times between individual M4A files and an MKA with a cue sheet. There's an error with the way Kodi reads the milliseconds. For example, in Robert Fripp's Exposure, there is a very short track of 6 seconds, which is read incorrectly as being 3 seconds if I use the correct time stamps (from the chapter editor cue sheet). If I round them all up to exact seconds (milliseconds are always 000), it's much better. All song durations are okay. If they are not rounded up, they can even be shorter or longer of 10 seconds (for no apparent reason).

 

[SeeMoreDigital]

Matroska files (MKV/MKA) use timestamps in milliseconds. Audio CUE files use ‘frame’ (60 per second I think) unit to measure less than 1 second....

As a reminder to anyone who's ever used gMKVExtractGUI.... It provides an option to extract chapters either as an XML, CUE or OGM file.

 

[Albert Dagger]

Matroska files (MKV/MKA) use timestamps in milliseconds. Audio CUE files use ‘frame’ (60 per second I think) unit to measure less than 1 second. I suspect this could cause a slight difference if a chapter has a value with > 600 milliseconds in its timestamp milliseconds value. Kodi does store the correct value in milliseconds in its database.

Its also possible the ffmpeg (used by Kodi) attempts to find the next keyframe in the file from the exact timestamp provided, I don’t know…

Also, I‘ve also thought actual chapter times are often incorrect on BD discs.

So, in your opinion, I can round up the milliseconds to either .000 or .600 for audio files, and it should work. Rounding up or down to .000 works well, but it’s not as precise as the original cue sheet with the milliseconds.

 

[himey]

INXS-KICK is an Atmos Blu-ray that should be played gapless.

 

[himey]

Kraftwerk's 3D The Catalogue

I took the time to split them into 8 albums, using this thread here as a reference.

 

[Albert Dagger]

I took the time to split them into 8 albums, using this thread here as a reference.

Thanks. For now, I decided to keep the two *mka files and create cue sheets with progressive track numbers. So, in Kodi, it's read as a single album with maaany tracks!

 

[ar surround]

Here is an issue that surprised me. I have taken rips of my Atmos albums (those that do not require gapless playback such as Abbey Road) and split them into chapters using MKVToolNix. The program splits them into chapters properly, but now there is an audio delay as the receiver tries to "re-detect" the Atmos signal between every track.

The delay cuts off the first second or so of audio on each track. The only way to hear a complete track is to use the back button to restart it. This is extremely annoying when one wants to listen to a whole album.

Does anyone know of a workaround for this problem? Is there some way of reassembling the chapters back into a single file, or do I have to re-rip the disc again?

 

[sjcorne]

Is there some way of reassembling the chapters back into a single file, or do I have to re-rip the disc again?

Load the first track into the dialog box, then right click it and select "append files". Then add all the others and start multiplexing.

 

[himey]

Here is an issue that surprised me. I have taken rips of my Atmos albums (those that do not require gapless playback such as Abbey Road) and split them into chapters using MKVToolNix. The program splits them into chapters properly, but now there is an audio delay as the receiver tries to "re-detect" the Atmos signal between every track.

The delay cuts off the first second or so of audio on each track. The only way to hear a complete track is to use the back button to restart it. This is extremely annoying when one wants to listen to a whole album.

Does anyone know of a workaround for this problem? Is there some way of reassembling the chapters back into a single file, or do I have to re-rip the disc again?

I doubt mkv tool nix adds anything. The problem is with bitstreaming. Simply adding the tracks back together should be fine.

 

[SeeMoreDigital]

I doubt mkv tool nix adds anything. The problem is with bitstreaming. Simply adding the tracks back together should be fine.

Agreed...When playing on my OPPO I use a continuous Dolby Atmos file muxed within the .mka container. And access/select the individual tracks using the following .cue navigation file: -

PERFORMER "Beatles, The"
TITLE "Abbey Road [2019 Atmos]"
REM DATE 1969
REM GENRE Rock

FILE "Abbey Road.mka" WAVE

  TRACK 01 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Come Together"
    INDEX 01 00:00:00
  TRACK 02 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Something"
    INDEX 01 04:20:15
  TRACK 03 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Maxwell's Silver Hammer"
    INDEX 01 07:22:32
  TRACK 04 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Oh! Darling"
    INDEX 01 10:50:30
  TRACK 05 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Octopus's Garden"
    INDEX 01 14:17:41
  TRACK 06 AUDIO
    PERFORMER "Beatles, The"
    TITLE "I Want You (She's So Heavy)"
    INDEX 01 17:08:26
  TRACK 07 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Here Comes The Sun"
    INDEX 01 24:55:53
  TRACK 08 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Because"
    INDEX 01 28:01:31
  TRACK 09 AUDIO
    PERFORMER "Beatles, The"
    TITLE "You Never Give Me Your Money"
    INDEX 01 30:47:02
  TRACK 10 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Sun King"
    INDEX 01 34:49:52
  TRACK 11 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Mean Mr Mustard"
    INDEX 01 37:16:02
  TRACK 12 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Polythene Pam"
    INDEX 01 38:22:37
  TRACK 13 AUDIO
    PERFORMER "Beatles, The"
    TITLE "She Came In Through The Bathroom Window"
    INDEX 01 39:35:22
  TRACK 14 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Golden Slumbers"
    INDEX 01 41:34:08
  TRACK 15 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Carry That Weight"
    INDEX 01 43:05:41
  TRACK 16 AUDIO
    PERFORMER "Beatles, The"
    TITLE "The End"
    INDEX 01 44:41:74
  TRACK 17 AUDIO
    PERFORMER "Beatles, The"
    TITLE "Her Majesty"
    INDEX 01 47:03:67

 

[M-K]

I've added an extra track (example as above):

TRACK 18 DATA
TITLE " "
PERFORMER " "
INDEX 01 47:28:00

at the end of the CUE file as workaround to see the duration of the last track .
For other albums use of course the duration of the mka file.

 

[SeeMoreDigital]

I've added an extra track (example as above):

TRACK 18 DATA
TITLE " "
PERFORMER " "
INDEX 01 47:28:00

at the end of the CUE file as workaround to see the duration of the last track .
For other albums use of course the duration of the mka file.

Out of interest... What device are you using to access and play your audio files?

 

[jimfisheye]

Mods, feel free to move this if there's a better place to post this thought! Don't mean to digress here.

I've had about 50/50 success trying to split before chapters. It seems like a similar issue to splitting a video file NOT on a key frame. When you do that, the result video is black screen until the first key frame. Then you learn that you have to split video files on key frames!

I'm playing Atmos encoded files (extracted to .mlp) with the Dolby reference player app. Half of the files I tried to split don't play and crash the reference player. It feels like a key frame-like thing. I don't know what the caveat is for this AC-4 in mlp type file. Not sure what other software tools that might allow for a more correct split. I was using MKV ToolNix.

Aside: Splitting files by chapter - which go by video frame - is crude for music to begin with. In fact it appears to have driven a resurgence of this now ancient full album audio file + cue file system to work around!
Video, you know... 24 or 30 samples/sec resolution.
Audio needs at least 1000 samples/sec resolution to split properly. (Sample rate itself is significantly higher that that.) So it is what it is and this isn't a complaint or perceived shortcoming. Just matter of fact that video tools and formats can't split audio properly for lossless gapless success.

Anyway, there's more to learn here!
Hopefully there will be a file conversion option to decode Dolby's proprietary encoding soon. Since they currently refuse to even sell it to consumers and all that business.

My plan initially is to roll whole albums to standard 12 ch wavpack file. Then I can split properly on zero crossings just like we've been doing with wav/flac and keep nice clean standard audio files in the archive. It's manual work though! A ripping utility that landed on wavpack output will be VERY welcome and the sooner the better!

Haha. Since we rarely get album covers and art anymore, playing a new album in a DAW app and looking at the waveforms has become the new version of taking in the album cover during first listen. Is that weird?