DTS HDMA audio muxing question

[OzBrickie]

Hi all,
long time away, thankyou again for your clever app.

Q. I have an mkv video file that contains DTS and AC3 audio. All good so far. I also have a matching DTS HDMA track that I want to mux into it but the track has been encoded in .flac. I assume to save space for transport. What do I decompress the flac track as, in order to mux it into the mkv file?

So I can easily decompress it into a wav64 but that doesn't seem right. I have a basic working knowledge of simple muxing using MKVToolnix.

The essence of my misunderstanding is based around what audio tracks physically are when they are in a video container. Are they wav's? Is it data? I have never really understood but if I am honest I have never really thought about it, primarily because MakeMKV is so slick and easy to use.

Thankyou
Oz

[Sunoo]

Why not just mux in the FLAC as is?

[ArArdin]

The essence of my misunderstanding is based around what audio tracks physically are when they are in a video container. Are they wav's? Is it data?

They are the same as prior to muxing. So a DTS track stays DTS, FLAC stays FLAC, PCM stays PCM etc. Should decompressing be needed, it will happen during playback by the proper decoder.
As Sunoo already suggested, you may wanna try directly muxing the FLAC track. Mkv(Toolnix) supports it and nowadays mediaplayers have no problem decoding it.

[OzBrickie]

Righto, gotcha both, thanks. I never even considered that the player would decode, but of course it would.

But lets say for arguments sake the player can't or I wanted to build a BluRay. I assume from what ArArdin says that I would make it a DTS HDMA, track then mux it in. What do I decompress the flac with to return it to it's original form? I am familiar with audio encoding/decoding but the science, like zip/rar, is beyond me.

Cheers
Oz

[ArArdin]

I never even considered that the player would decode, but of course it would.

Well, that's something you'd have to try out. There are (older) players that don't decode (multichannel) FLAC.

For lossless compressing into BD compliant audio you'd need either the DTS-HD Encoder Suite or Dolby Media Encoder. Both are not free. BD doesn't support FLAC.
Compressing is not mandatory for BD though. FLAC decompresses as pcm. Because your FLAC already has DTS-HD MA as source, its decompressed (multichannel) PCM should be blu-ray compliant. Eac3to can do the decompressing for you. Just choose w64 as output. Which result can directly be imported in tsMuxer for BD output. Of course decompressed audio is bigger in size.

[OzBrickie]

Thanks mate. That makes sense.

I did decompress as w64 when I first started mucking around but I wasn't sure if muxing a wav into the container was right. So my understanding now is that wav is a PCM stream and w64 supports the large file size (this one is 8Gb once decompressed) but I can mux as flac if my decoder supports it.

I only use my Denon AVR as a hardware decoder, and I know it handles flac, everything else is served from a "PMS" type media server which supposedly de/recodes on the fly but always seemed, in my limited knowledge and opinion, clunky.

Thankyou, I will give it a go, both ways just for fun!

Cheers and beers
Oz

[ArArdin]

So my understanding now is that wav is a PCM stream and w64 supports the large file size (this one is 8Gb once decompressed) but I can mux as flac if my decoder supports it.

Correct.

I only use my Denon AVR as a hardware decoder, and I know it handles flac

May I ask how you feed FLAC from a videofile to your Denon? Never considered, but is this possible over HDMI? Usually an inbetween player decodes FLAC and puts out PCM to AVR.

[GnomeFondler]

Righto, gotcha both, thanks. I never even considered that the player would decode, but of course it would.
Cheers
Oz

Oddly enough, since it's the only one not documented at all, FLAC is the only lossless track type that's usable as a primary audio track in MP4s for LG's built in player (needed if you also need Dolby Vision since the TV can't play DTS-HD MA at all and substitutes screeching noise for TrueHD or multichannel .w64 as the first track). Dolby Vision isn't supported with MKV files and FLAC isn't supported in .m2ts Unfortunately it was never really intended for interleaving with video as cleanly as the disk formats so it'll choke up your video pretty badly if you have multiple FLAC tracks or a 5.1 channel FLAC + very high bitrate video. This seems to happen even when the whole is well within the artificial bitrate limits created by their 100Mb NICs. If you're only playing on a PC dolby vision doesn't matter much anyway (although Profile 8.x works as software-led only in MP4 in "Movies and TV" only with the Dolby Vision extension from the store) and you could probably encode literally anything the container will take and have it work.