More of a curiosity, than anything else...
Many of the projects here include audio ripped from Cinema DTS discs, which I think is absolutely awesome! But given that DTS is now no longer used in theaters, making way for Datasat Digital Sound. My question is... Would it be theoretically possible to rip the audio from Datasat CD-ROM's used in theaters? Assuming, of course, that one would be able to get a hold of these discs... If so, I may be on the lookout for certain titles.

The Datasat system for film is the same system that DTS used. CD-ROMs in other words. They just bought the business from DTS and slapped their name on it. If you could get a hold of the discs they would be decrypted the same way as the DTS discs.

Sadly, nowadays most films are digital (DCP/DCI). Jetrell Fo can probably chime in but I think its harder and harder to find the discs for newer films. Basically, most DCP files have an embedded PCM 5.1/7.1 soundtrack (even Auro 3D is "un-stacked" from a PCM track) or an Atmos soundtrack (has a channel system with meta data for object direction). So unless you can get a hold of the DCP, the days of us getting a hold of the true movie soundtrack are coming to a close.

But its not that bad. Frankly I never would of thought we would of gotten access to theatrical soundtracks till Jetrell came up with his great project. Not only that but now scanners can get the analog tracks, mag and sometimes Dolby Digital. Its a great time.

If you ever want to see the soundtrack format that a DCP has, this is a good sight I like to use:

http://digitalcinema.bydeluxe.com/

Also DTS is re-entering the theatrical market with their DTS-X system. I believe they are aligned with Datasat, Barco (Auro 3D) and a couple of others. I think they want it to be the default object based system for DCPs. So there in another Dolby vs DTS battle heating up.

Thanx for the explanation PDB. I was curious about this too.

(2015-07-16, 02:58 AM)jerryshadoe Wrote: Thanx for the explanation PDB. I was curious about this too.

No problem

I had no idea about all of that... Thanks PDB!

Any ideas on how one might go about trying to track down DCPs? I know there's the DCP for Back to the Future "out there..." Anyone know where that one came from?

DTS-X... I had no idea they were re-entering theaters! I read a bit about it and it seems pretty cool!

(2015-07-16, 03:44 PM)nafroe Wrote: I had no idea about all of that... Thanks PDB!  

Any ideas on how one might go about trying to track down DCPs?  I know there's the DCP for Back to the Future "out there..."  Anyone know where that one came from?

DTS-X... I had no idea they were re-entering theaters!  I read a bit about it and it seems pretty cool!

I'm not the expert so take what I say with a grain of salt.

You can't do anything with the any DCPs files (the one you want is called MXF). DCP files are sent to theaters on hard drive (sometimes satellite) and then uploaded to a local server (colorfully called ingesting). If you knew someone at a theater you could probably get a copy but those files but they would be useless to you because of the copy protection. Even on the server you can't play the files. The movie company have to deliver the keys  before the movie can be played. The keys unlocks the files to be played by a specific projector at specific times in AES encryption (can't remember the bit size). The DCP projector actually contain a hardened box inside it that contains the decyrpting electronics. Tampering with that could invalidate the projector and the movie studio won't issue keys for it. So you are out hundred of thousands of dollars if you tamper with it, no business owner is going to do that. If you were super rich and bought a DCP projector, it normally will not included the hardware for key detection.

The exception is trailers. Often movie companies don't bother with encrypting the trailers. After all those are just ads. But on the other hand, Imax does encrypt their trailers. That's why the IMAX Star Wars VII trailer never (I think) made the rounds with its unique aspect ratio for the Falcon scene. Regardless, in some spots in the wilds of the net you can find trailer DCP files.

So the question is what about BTTF?  Some said it was just a HD master used for the BDs while other said it was from a non-encrypted DCP. The current thinking is that it is the later. Mostly since someone posted some of the original 2K files (which I would love to get). They where clearly not the same as the 1080p files passed around. So this is where the story has a little conjecture. Some people have said that the movie companies didn't bother encrypting older films with keys. I guess either laziness, money saving and/or the thought that no one would want to bootleg an older film (boy were they wrong). So in the earlier digital projection days a lot of old films were not encrypted. That doesn't happen anymore, maybe because of BTTF or maybe someone just wised up. BTTF DCP started on an invite only site where we think it was "ripped" by a projectionist who noticed there was no protection and slowly made its way into the wild.

If you could get the files decrypted, what would you see? This is the cool part. The MXF file in nothing but a container for a bunch of picture files and PCM sound files. The DCP is not a video file but in fact thousands of jpeg2000 pictures files. So in a lot of ways similar to old 35mm projection, its just showing one picture at a time. The sound is just PCM in 5.1 or 7.1 configuration (Atmos being different). The size of those files start in the hundreds of gigs and moves up from there. It doubles for 3D and 48Hz. So the Hobbit in 3D, 48Hz was said to be a huge file.

Back to DTS. In the late 2000s, DTS saw the writing was on the wall. That 35mm film was on the way out so they sold their theatrical business to Datasat. Datasat is basically a caretaker, running what's left of the DTS business (they do other things, I'm just reference only the DTS business). DTS itself became an only home sound business. They did very well on BD because they offed their encoders for free whereas Dolby charged fees.

Meanwhile, Dolby was effectively pushed out of the theatrical business also. You don't need Dolby compression/NR if your soundtrack is in (zero licensing fee) PCM. So they decided to come up with a new system they could make money off in theaters. The answer was Atmos. Atmos, to simplify, takes the traditional channel system (5.1/7.1) and adds an object layer. That's a whole technical discussion for another time but object based sound system has been a dream for sound engineers for awhile now.

DTS was working on their own object based system for the home when SMPTE (Society of Motion Picture and Televsion Engineers) put out a call for a universal object sound system to be incorporated into the next revision of the DCP standards. Dolby proposed Atmos. DTS seeing a chance aligned with a bunch of other companies and created the MDA (Multi-Dimensional Audio) group. There a lot of difference between the two but MDA is basically DTS version of DTS-X for theaters (Theatrical and home Atmos vary also).

Anyway I went long, sorry. I love talking about this crap.

I do not have any Datasat Audio discs. They are very difficult to get a hold of but I'm sure that if there was someone who had something I needed, it might well find it's way to me with patience.

Well, with all the luck you've had getting DTS discs, maybe this has a future too

It is always a possibility for sure.

(2015-07-19, 10:04 PM)Jetrell Fo Wrote: It is always a possibility for sure.