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DTS HD 7.1 goes to 5.1 in the mkv file

Posted: Sun Oct 04, 2015 10:16 pm
by PegasusRider
The movie is being read as 7.1 in the MA and a 5.1 below that as the next selection. I would say based on what I've been able to read that the second entry is the DTS core and unnecessary if you are taking the MA (master?) track.

Assuming that is correct...

Why is the disc reporting 7.1, but MakeMKV is copying out 5.1? Even though it retains the 7.1 text there are only 6 channels of audio.

I'm fairly new to caring about the audio fidelity, so I probably have something set up wrong.

I've tried searching about a 100 ways, but with the site issues the last few days, that's been... fun. Here and there I've found some hints, but not sure what applies now that dtsdecoderdll.dll is now "built in" (or at least it's functionality). I've also tried some other software to extract the audio directly from the disc, but since MakeMKV came along other "ripping" software became pretty useless to me, so I can't actually get readable files that way either. :/

So... since MakeMKV is pulling out complete streams, I must have something set wrong... or it's doing it wrong in the first place. Or the disc is lying but I don't know how to verify. Or some other silly thing I haven't thought of.

At any rate, thanks in advance for any assistance and/or illumination in this. :)

Re: DTS HD 7.1 goes to 5.1 in the mkv file

Posted: Mon Oct 05, 2015 7:35 am
by PegasusRider
OH! So sorry.

If it is a stream extraction, I don't get why you have to write it with the FLAC profile option selected to actually get 7.1 instead of 5.1... I vaguely recall this being said somewhere but I didn't understand it at the time, and of late had hoped it had changed (especially since I couldn't find the pertinent info anyway :( ). If there was an explanation of why this was necessary I missed it.

I'm pretty sure it's a programming technicality I hope someone will be willing to explain at some point. But I could have sworn I got 7.1 from TrueHD just fine, I'll have to find a disc and double check.

Re: DTS HD 7.1 goes to 5.1 in the mkv file

Posted: Tue Oct 06, 2015 3:22 am
by PegasusRider
Okay, some additional information for anyone that can later find it here... if you are interested in such things, and it doesn't change (totally not to be expected, but maybe it will help someone in the meantime).

If you intend to ever edit 7.1 audio... be sure to set the FLAC option in the profile.

If you use Audacity... please know that as of 2.1.1 anyway, it does not support 7.1 playback, or any playback involving more channels than 2. So you'll have to deal with that issue as well, but don't freak out like I did, it's expected currently.

If you are a tricky sort, you can use the trial version of Sound Forge Pro 11 and get 7.1 playback through it, plus proper handling of all the channels output by MakeMKV. It does in fact put the proper metadata in the flac stream... so it's all quite handy. Just getting the right combo of apps can be a chore.

So, what I've found helpful so far, app wise to augment MakeMKV...

MKVToolnix with the gMKVExtractGUI, Audacity (if you can't wrangle Sound Forge Pro 11), and a bit of patience. VLC seems to do the playback properly if using Audacity, and you likely already use that if you're making digital back-ups. Also, if you need to manually set the metadata for channel info on the save of the edited file, mp3tag may be a handy addition. (the extended tag would be "WAVEFORMATEXTENSIBLE_CHANNEL_MASK" with the data of "0x63F" for 7.1, but you can look up that coding at Microsoft for all the different flag possibilities.)

Even if you CAN get .thd accurately from MakeMKV... it doesn't matter because neither Audacity nor SFP11 will save in .thd Also .dts doesn't seem to be much better at this time. So stick with .flac and you can do what you need to and actually save the files for later use.