MKV MKA M4A

Sal1950

Hey Jona's
Hope all is well with you and yours during these trying times.
Thanks for all the work you've put into Strawberry, you've done an amazing job over the last few years for us audiophiles. Currently it works perfectly to pass all my 5.1 multich flac and wav files to my Marantz pre/pro over HDMI.

I'm trying to get my Atmos files to work in SB but have a few issues I'm hoping you might help with.What I'm wondering if it's possible to get either MKV, or MKA, to be recognized as a file types, these two containers will carry Atmos.

Also M4A will carry Atmos but when I attempt to open a file I get the error popup
"Your GStreamer installation is missing a plug-in."
Any idea which plugin this could be or how to determine that?

As far as I know, when SB is configured to pass bit perfect to Alsa it should be able to also carry Atmos in one of these containers. But much more than this is beyond my skillset. Would really love to get Atmos working here.
TIA,
Sal1950

jonas

@sal1950

Thanks!

Matroska isn't recognized because TagLib does not read it in the latest stable release of TagLib.
However, the TagLib 2 (unrelased version) supports it, but no-one is working on that currently. So the only way to get Strawberry to read it is to use TagLib from unreleased code.

I don't think it is easy to get Atmos working, looks like there isn't an open source decoder for it. I found this:
https://gstreamer-devel.narkive.com/5wukVmFB/query-regarding-dolby-atmos-support-in-gstreamer

damian101

@jonas Dolby Atmos can carry an embedded Dolby TrueHD stream, and on commercially released Blu-rays that's always the case. TrueHD is a lossless codec which can can be bit-perfectly decoded by FFmpeg.

animaldaydream

@damian101 I copy the stream of DCA and AC3 streams from a DVD, into mp4a and m4a files, as a last resort, to avoid transcoding. Strawberry can play both of these.

I also compress DSD streams losslessly using WavPack. Strawberry can't play them, compressed or not. But to be fair, its closest GTK alternative Quod Libet, also can't play them. I think the only reliable music library based player for these is MPD. It'll even convert it to DoP if you need it to.

But when the stream is PCM, I just transcode to FLAC. It's lossless anyway, so nothing changes.

If you're not willing to go through the trouble of finding a player that can play TrueHD audio, doesn't it make more sense to transcode to FLAC? Since it's lossless, technically it should be fine. There must be a way to get MPlayer to do this. (It can convert audio to WAV; however by default it downsamples to 2 channels @ 48kHz). FLAC can handle multiple channels, high bit depths, and high sample rates, so long as they're PCM.

It might seem possible to use ffmpeg to transcode the PCM audio, but apparently it only supports one channel configuration for surround, so channels are switched around. Just set the bit depth and sample rate on mplayer, and output to a WAV file.

Here's the command I used for Ola Gjeilo's Piano Improvisations:

mplayer br://[title] -bluray-device [disc mount path] -benchmark -vc null -vo null -aid [audio ID] -chapter [start chapter]-[end chapter] -ao pcm:fast:file=[output path]

You might need to switch things around. Replace the square brackets as needed.

It does the job one chapter and title at a time; if you don't set an end chapter, you'll end up with a file with all the chapters concatenated.

Also, bdinfo will print out the audio IDs on the disc. Some distros have bluray_info instead; I don't know if it does the job.

You'll have to figure out the title and chapter using VLC.

If your Blu-ray is encrypted, you'll have to use MakeMKV. It's not free though. Also, the output is an MKV file, so all commands to extract audio from the MKV file will be different; I haven't figured them out yet. MPlayer is very hard to use...