questions/help needed inre HD DTS and Flac

[spiritgumm]

I have a compressed bluray (Mkv and Flac) which originally had DTS audio. I'm assuming the audio wasnt altered, and was converted directly to Flac, but perhaps the specs below will indicate if I'm wrong about that.
Assuming it was DTS->Flac, how would I decompress Flac->DTS? I thought Flac was analogous to zipping a file so unzipping would restore it's original properties. However, there is no DTS option in Foobar's conversion list. Do I convert to wave, then convert wave to DTS? If so, is this all lossless?
The Flac is variable bit rate, but the DTS appears to be constant (I read elsewhere).
Here's the specs of each:

DTS-HD Master Audio
English 1617 kbps
2.0 / 48 kHz / 1617 kbps /
16-bit (DTS Core: 2.0 / 48 kHz / 1509 kbps / 16-bit)

Format : FLAC
Format/Info : Free Lossless Audio Codec
Duration : 1h 29mn
Bit rate mode : Variable
Bit rate : 178 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 114 MiB (100%)
Writing library : libFLAC 1.2.1 (UTC 2007-09-17)

[poisondeathray]

Actually - It depends on how you converted to flac, and the decoder used. Flac itself is lossless compression, but some decoders and programs will dither and not produce 1:1 exact copy

I thought Flac was analogous to zipping a file so unzipping would restore it's original properties.

No - it's very different. You can't get the original audio compression back unless you use lossless compression again (and this is only the case because DTS MA was lossless in the first place; if it was lossy audio, you could never get back the original audio compression). But if you converted to flac properly , the uncompressed audio will be the same. That is original audio uncompressed, vs flac uncompressed will be the same

But DTS MA is lossless , so if you encode the flac back to DTS MA - it will be completely lossless if done correctly. But there are no free encoders. You need the DTS Master Audio Encoding Suite (~$1500)
http://www.dts.com/professionals/audio-software/dts-hd-master-audio-suite/overview.aspx

[spiritgumm]

Actually - It depends on how you converted to flac, and the decoder used. Flac itself is lossless compression, but some decoders and programs will dither and not produce 1:1 exact copy

I didnt convert anything - I have a compressed bluray, and just want to restore the audio to the original format (which was DTS, according to online sources). I figured it was converted directly to Flac, and was hoping it could be decompressed back to Dts, just as Flac (from wave) can be decompressed back to wave (in a lossless process).
Apart from my stated goal, I also need a wave for another reason. I'm assuming that's a no brainer using foobar.

[poisondeathray]

Just re-rip the bluray track and you will get DTS-MA. blu-ray doesn't use flac

If you mean you no longer have the blu-ray , only the mkv backup, there is no way except to use the expensive software (and that doesn't mean you will get identical audio, because as mentioned earlier, often other processing gets thrown into the mix, like fixing levels, removing dialnorm. Unless you know EXACTLY how the flac was made....)

[El Heggunte]

[ ...... ]

[spiritgumm]

Just re-rip the bluray track and you will get DTS-MA. blu-ray doesn't use flac...If you mean you no longer have the blu-ray...

yeah, I never had the bluray, otherwise I would have simply re-ripped the audio. I thought perhaps seeing the "Writing Library" spec might indicate how the DTS was converted or decoded. Foobar has a DTS decoder - I cant tell if it can be tweaked when outputting - but the idea of using lossless Flac hinted to me that the original encoder was trying to keep the best quality, just as Flac is used for lossless compressed wave.
Anyway, PoisonDR, thanks (as usual) for the heads up about the Dts encoder.

[spiritgumm]

[ ...... ]

I saw the link to the program you mentioned, though I'm not sure how to implement it.

[poisondeathray]

dcaenc is a command line program. There is no GUI

It cannot encode HD audio (only vanilla DTS, not DTS-MA like the original on blu-ray)

Whether or not you can actually hear the differences is another topic

[spiritgumm]

dcaenc is a command line program. There is no GUI

It cannot encode HD audio (only vanilla DTS, not DTS-MA like the original on blu-ray)

Whether or not you can actually hear the differences is another topic

lack of GUI could be a problem for me. And I'll have to see what the intended audience would tolerate if the original format wasnt available.

[FulciLives]

If you absolutely need DTS-HD MA then buy the Blu-Ray.

Otherwise leave the audio as FLAC if it plays that way on your equipment. It should be fine if you are playing back from a computer but media player support may or may not be there. If you are using some sort of media player and it plays the FLAC file then so be it (in other words just leave it be) but if it doesn't play it then you'll have to convert it to something it can understand. Best chance of compatibility at that point is to convert the flac to a LPCM WAV audio file. That should work with any media player and give you identical sound to the FLAC (although the file size will be MUCH larger). Otherwise you have to convert to either regular DTS and/or regular AC-3 and at that point you are compressing to a lossy format so you want to avoid that unless your media player can't play FLAC/LPCM audio in a MKV file.