DTS-HD Decoding (ffmpeg?)

[liquidskin76]

Hi,

Does anyone know if DTS-HD decoding is being worked on in any project (i.e. ffmpeg), and if so at what stage of development it's at?

I can't seem to find any info on the subject.

Many thanks!

[The Herminator]

I believe it still only decodes the lossy core.

[liquidskin76]

That's right.

Hopefully someone somewhere is working on the HD decoding. I believe documentation on the workings of DTS-HD is hard to come by.

Cheers

[ramicio]

I doubt it will ever happen. The papers cost thousands of dollars, and I'm pretty sure if a person purchased the specs and used them to write a freeware codec, DTS would send a SWAT team to bust down their door. Even if it is partially figured out, it won't be compliant and will be buggy. Just look at the ArcSoft decoder. There is so much crap that it won't even work on correctly (mono, HiRes, weird 7.1 channel-arrangement stuff, etc.) and that is an official, royalty-paid decoder.

[mindbomb]

arcsoft works perfectly.

eac3to is tuned for a certain version (4/25/2008). Not using that version will cause anomalies.

lav audio works with all versions i think. or at least the latest.

[ramicio]

I don't know how to convince you any differently, but I have a bunch of versions of Arcsoft, and they all have the same problems with the one weird 7.1 speaker scheme, anything Mono (lossless or lossy), and 6.1 stuff. I have to revert back to a virtual machine of XP with the DTS Suite software, make a fake file to grab a header from, slap that header into the file I'm working with, use the DTS Suite's player to give me my WAVs, then use something like WaveWizard to give me a multichannel wave, then finally eac3to to give me a FLAC.

[nixo]

I doubt the fact that DTS-HD is proprietary is a major stumbling block; those devs seem to be able to RE just about anything. Perhaps it is just a lack of interest/time.

EDIT: "those devs" meaning FFmpeg/Libav.

[ramicio]

Well, even so, it wouldn't be a fully compliant decoder, it would just be a guess on how the standard is written, unlike all of the Dolby equivalents which seem to be nice and open. There was plenty of black-market ALAC crap, but they were all guesses, then the code was opened.

[kieranrk]

The Dolby equivalents are not nice and open at all.

[ramicio]

Still dead in the water. I see foobar has had a plugin to decode DTS-HD for quite a long time...

[amtm]

Well, even so, it wouldn't be a fully compliant decoder, it would just be a guess on how the standard is written, unlike all of the Dolby equivalents which seem to be nice and open. There was plenty of black-market ALAC crap, but they were all guesses, then the code was opened.

That's not true. There are ETSI documents that cover the DTS specs. The latest spec from last August that can be found here (http://www.etsi.org/deliver/etsi_ts/102100_102199/102114/01.03.01_60/ts_102114v010301p.pdf) which in addition to what was in the previous ETSI spec it also documents the XCh extensions, the DTS Extension substream, DTS Lossless Extensions, etc. ffmpeg will never be able to be a licensed compliant decoder, but using that spec it could be made to be compliant with all streams.

[ramicio]

Well they decode lossy DTS, and I thought that was illegal to do without license. Half of the problem is how Blu-ray or at least whatever rips them ruins the headers of DTS-HD Master.

[amtm]

Well they decode lossy DTS, and I thought that was illegal to do without license.

It would most likely run afoul of US software patents but since most ffmpeg developers aren't in the US nor is the project hosted within the US it's no different than any other patented format that they include code to decode and encode.

Half of the problem is how Blu-ray or at least whatever rips them ruins the headers of DTS-HD Master.

Then extra code would be needed to cover corrupted headers but that doesn't sound like those would be compliant files. But this is no different than for any other format where obviously you will need to handle cases of headers being corrupted, etc anyway.

[Qaq]

I see foobar has had a plugin to decode DTS-HD for quite a long time...
Based on same .dll from TMT as eac3to and LAV audio, AFAIK.

[ramicio]

Based on same .dll from TMT as eac3to and LAV audio, AFAIK.

Yea, I noticed that as I read into it. How lame.