Export 5.1 MKV to 5.1 FLAC

HI there:

I will try not to bore you, but just the briefest background here: I am ripping all of my 5.1 audio discs (DVD and Blu-Ray) for importing into my Plex media server. MakeMKV does a nice job on the rip, and I can play those just fine in 5.1 in Plex. But, I lose the ability see and skip tracks, etc. I decided that I had to edit the files to individual tracks, and I do everything in FLAC. I was beating my head against the wall for a bit, using a combo of MakeMKV, VLC, and Audacity. Then, the lightbulb moment: ffmpeg plugin for Mac/Audacity! I can now natively import the MKV file, and see all six track (the 5 and the .1). Now to export to 5.1 FLAC.

After my first failed attempt, I realized I had to change the export options to Use Advanced Mixing Options. When exporting, I get the attached screenshot. Yes!! I exported the file to my desktop (just testing at this point), and it plays fine through my stereo speakers. I then move it into the Plex server, and go to my home theater. Oh no! I’m not getting output from my surround speakers. Thus, my ask for help here.

Other than the Advanced Mixing Options, I didn’t see anything else to change. Any advice anyone can give me? Anyone done this before?

MacOS 12.3.1; Audacity 3.1.3

Screen Shot 2022-05-23 at 2.03.43 PM.jpg

You can open the 5.1 channel FLAC in Audacity to see if all the channels exist in the FLAC.

Does Plex play surround from your computer’s soundcard or are you sending it to your home theater via S/PDIF or HDMI. If you are sending it to your home-theater receiver, I believe it’s up to the receiver to decode it and they don’t all support FLAC.

I’ve only played-around with MKV a couple of times but I think MKV is has a way of saving or creating chapters. Or, there should be a way to split it into separate files. (I don’t think you can keep the menus.)

There are also rippers that can crack the copy protection and copy the DVD or Blu-Ray to your hard drive in the original format where you can play it directly or burn a disc without the copy protection. But, software that cracks copy protection is illegal and I don’t know of a free Blu-Ray ripper. Also, VLC doesn’t support Blu-Ray (at least not completely) so you’d need something like WinDVD or PowerDVD to play Blu-Ray files.

Hi DVDoug:

I like that idea of opening the FLAC in Audacity; maybe this is a clue…The file doesn’t “open” per se; it imports. I do see all six tracks after import, but there is some conversion that’s going on, apparently. I know that a flat FLAC file can handle up to 8 channels (7.1, I guess…).

A riddle, wrapped in an enigma.

Thanks, man. I think this is a valuable clue…

Ah ha! I figured it out. Again, you (inadvertently) pointed me in the right direction…

Plex media server will let you play a song, before it’s done analyzing it. So, it hadn’t processed all of the channels when I first went to listen. (Actually, I guess it’s still processing, because I now have all the channels except for the center. Fingers crossed).

Thanks again for sounding off. It really did turn on that lightbulb for me!