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Topic: DTS decoding

Aaron Garman
Phenomenal Film Handler

Posts: 1470
From: Toledo, OH USA
Registered: Mar 2003

posted 04-05-2004 02:28 AM

Well, I will admit the program works, but with those trade off's Bobby mentioned. However, it does make for good testing of individual speakers, most especially the center channel. I had some old discs lying around and used a sample of George Clooney's voice. It sounded fantastic. It really does make me wonder how much the studios change the mix for a DVD because everything I threw at my speakers sounded so much crisper and clear than DVD counterparts. Thoughts?

EDIT: It was also fun to hear an old Cinemark snipe at home. Can you say Windows startup sound? [Big Grin]

AJG

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Patrick de Groot
Expert Film Handler

Posts: 161
From: Sprang-Capelle, Netherlands
Registered: Apr 2001

posted 04-05-2004 05:34 AM

Does someone else who got the "package" have any idea where start.exe is for? Some virus scanners say it contains a virus someother say not... Since I have just bought a new computer I checked it first out on my old one. Start.exe doesn't seem to do anything visible.
However you don't need start.exe to play DTS files so just leave it alone.
What I do miss is the option to output all channels to a 5.1 soundcard at once...
Does someone already experimented with playing the Dolby Prologic an Prologic 2 downmixes? How does it sound?

edit
I have also found an archive without the start.exe. So it seems you should ignore that file.

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Mark J. Marshall
Film God

Posts: 3188
From: New Castle, DE, USA
Registered: Aug 2002

posted 04-05-2004 11:36 AM

quote:
'scuse me... but isn't this a bit out of sorts... a group of technical professionals, discussing the hacking of that which we operate for a living?

I maintain a wide area computer network for a living, and I try to hack and break into things on our corporate network all the time. Of course, I wouldn't try to steal from myself, but the skills I've aquired have helped me help others who lose access to things on their networks for example.

No one is discussing stealing anything, only how things work, and what would and would not be possible, and what would and would not be legal. I think it's a pretty interesting discussion, actually. But that's just me.

Edit to fix stupid mistake.

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Aaron Garman
Phenomenal Film Handler

Posts: 1470
From: Toledo, OH USA
Registered: Mar 2003

posted 04-05-2004 01:12 PM

quote:
Does someone already experimented with playing the Dolby Prologic an Prologic 2 downmixes? How does it sound?

Well, it sounds fairly good, almost like a DD5.1 track on DVD being downmixed to two channels, but not quite that compressed. You can definitely hear a difference if you play each channel individually. Hopefully, some sort of support for 5.1 would eventually be possible.

AJG

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Bobby Henderson
"Ask me about Trajan."

Posts: 10973
From: Lawton, OK, USA
Registered: Apr 2001

posted 04-05-2004 05:13 PM

quote:
It really does make me wonder how much the studios change the mix for a DVD because everything I threw at my speakers sounded so much crisper and clear than DVD counterparts. Thoughts?

This is just a guess, but I would strongly bet you're hearing evidence of the "X-curve" being applied. Theatrical mixes are often made with more treble to counteract the filtering away of high frequencies that occurs in commercial theater auditoriums. This was one of the main justifications for "Home THX" re-EQ, basically to strip away that overly bright treble.

Audio editing tools these days are so much more powerful and flexible that we're seeing multiple 5.1 mixes tailored for different environments. You have your X-curve altered commercial mix. Then you get a "near field" home theater tailored mix. New Line Cinema has been a strong proponent of this approach, establishing the standards bar on DVDs like the Platinum Edition of "Seven". Some of their DVDs, such as "Blade II" mention the specialty of the near field mix and advises to turn off re-EQ functions.

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Bruce Hansen
Jedi Master Film Handler

Posts: 847
From: Stone Mountain, GA, USA
Registered: Dec 1999

posted 04-05-2004 05:50 PM

I don't see how anyone could use the output from a DTS theater disc to add audio to a video tape or DVD, there would be no way to keep it in sync. Same thing for making a multi channel recording one track at a time from a DTS disc, there is no way to keep everything in sync.

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Joe Redifer
You need a beating today

Posts: 12859
From: Denver, Colorado
Registered: May 99

posted 04-05-2004 06:20 PM

Bobby, the subwoofer information (I refuse to call it "LFE" because that is lame) is indeed in the surround channels. You have to run the crossover yourself. Extract it out of the surrounds.

Bruce, exporting one channel at a time definitely stays in sync. I have no idea about syncing it to camcorder video, though, nor do I really care. Why have great sond when your video looks like crap? The pirated screener DVDs usually have 5.1 AC3 anyway, so I don't see why anyone would bother.

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Aaron Garman
Phenomenal Film Handler

Posts: 1470
From: Toledo, OH USA
Registered: Mar 2003

posted 04-05-2004 06:53 PM

I'd really love to be able to do A/B tests with this to see what real differences there are. I'd love to compare it to some AC3 or DTS laserdiscs too. I was told many of the LD's were just direct copies of the theatrical soundtracks, with no new near field mixes made. Maybe my theater would just let me borrow a DTS 6... [evil]

AJG

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Bobby Henderson
"Ask me about Trajan."

Posts: 10973
From: Lawton, OK, USA
Registered: Apr 2001

posted 04-05-2004 09:46 PM

The AC3 and DTS audio from old laserdiscs would probably still sound better than an audio extraction and rebuild in DD/DTS from a DTS movie CD-ROM. Again, the audio on the CD-ROMs is already lossy compressed and then you have to lossy compress it again to get it to play back on your home theater gear.

Even if the AC3 and DTS laserdiscs used theatrical sound mixes, they got that audio encoded from the uncompressed digital or SR mag analog 6-track masters/stems. With a DTS CD-ROM you are not starting from a master quality source.

I imagine it might be kind of nifty to extract and build up a home DD or DTS track from a DTS CD-ROM just from nuts and bolts curiosity of how things work. But with the time and work involved and bringing it all together, why bother? I certainly could not see making a practice out of doing that. My time is worth more to me than that. I would just cut out the hassle and go buy/rent the regular DVD.

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Marin Zorica
Jedi Master Film Handler

Posts: 671
From: Biograd na Moru, Croatia
Registered: May 2003

posted 04-06-2004 04:01 AM

Yes, is wonder what pc's can do now today, but are we little of the rely subject of discusion, because we now talk of extracting dts sound, dvd's all thing, but the really subject of disscustin is decoding dts in theatres, and how that work. Also what is with that APT decoder, anyone else try it?

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Patrick A. Meister
Film Handler

Posts: 22
From: Switzerland
Registered: Aug 2003

posted 04-06-2004 04:53 AM

<<With films ve got a dts disc but because we got only analog optical sound ve can't play dts, but i try to play dts on PC with no results.

Are there some software for playing dts on PC or something similar, does is possible to connect dts time code reader to PC and play????>>

THERE IS a possibility to run them
I can't tell it to you [Wink]

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Patrick de Groot
Expert Film Handler

Posts: 161
From: Sprang-Capelle, Netherlands
Registered: Apr 2001

posted 04-06-2004 12:38 PM

Just a thought which has crossed my mind before...
A PC with the proper software and soundcard can ofcourse replace a DTS player. Just plug the timecode reader to the serial port (or whatever) and synchronize the player with this signal. You can output the sound analog or digital to a Dolby processor. Heck, you can even do equalization emulation on the PC but I would probably prefer the analog real equalization of a Dolby processor.
You can buy some professional PC audio hardware/software.
The only legal problem is maybe that the timecode is a propietary format of DTS which is stupid btw...
DTS wouldn't be happy about it, but after all the DTS player is a low-end PC with custom hardware added (with duplicated functionality of a Dolby processor).
It would sure be a lot cheaper!

You can also input the analog Dolby SR signal into a computer and process it... if you have the software for it.

Professional audio software like Cubase SX shows the audio capabilities of a modern PC.

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Aaron Garman
Phenomenal Film Handler

Posts: 1470
From: Toledo, OH USA
Registered: Mar 2003

posted 04-06-2004 01:25 PM

Something interesting I found was a program that allows one to mix a Meridian Lossless (MLP) track for a DVD-R. I wonder, just for fun, what kind of results that would merit if the source was the DTS CDROM?

AJG

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Antonio Marcheselli
Phenomenal Film Handler

Posts: 1260
From: Florence, Italy
Registered: Mar 2000

posted 04-06-2004 01:36 PM

I knew that software and my fear is that it can be used to make DIVx software that is so popular during these days.

What do you think about?

Bye
A

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Bobby Henderson
"Ask me about Trajan."

Posts: 10973
From: Lawton, OK, USA
Registered: Apr 2001

posted 04-07-2004 01:02 AM

quote:
A PC with the proper software and sound card can of course replace a DTS player. Just plug the timecode reader to the serial port (or whatever) and synchronize the player with this signal.

You might technically be able to get a hacked together system like this to work. But as you mentioned, DTS would not be very happy with it. In fact, anyone operating such an informal setup in a commercial theater with paying audiences would put themselves at great risk of a very expensive copyright lawsuit. At the bare minimum, you would have a hell of a time trying to get on DTS' distribution list. Good luck on getting discs!

quote:
Something interesting I found was a program that allows one to mix a Meridian Lossless (MLP) track for a DVD-R. I wonder, just for fun, what kind of results that would merit if the source was the DTS CDROM?

In the very best case scenario, you would get no better audio quality than what was on the DTS CD-ROMs. You cannot hyper inflate audio bitrates up to the levels boasted by MLP and expect added nuances to appear.

A good analogy would be taking a low rez JPEG image from a web page and running it through a $250,000 3M Scotchprint graphic maker for a billboard. The Scotchprint machine's RIP hardware would interpolate lots of extra pixels, but the end result would just be very fuzzy and look like shit.

When you mention MLP apps, are you talking about Minnetonka Audio's Surcode apps? They make a wide variety of surround sound software encoders for DD, DTS and MLP. Their MLP encoding app costs $2495. Pretty damned pricey. Even more so than the $1995 they want for their DTS DVD audio encoder (they sell a separate DTS music CD encoder for $499). About the least expensive way Minnetokna/Surcode will allow you to do 5.1 is with their Dolby Digital 5.1 encoder plug-in for Adobe Premiere Pro. According to their website, the DD 5.1 plug in is already built into Premiere Pro, you just have to pay Minnetonka $295 to activate it. I would expect to see an activation hack for that floating around the Internet, if it isn't doing so already.

quote:
but the really subject of disscustin is decoding dts in theatres, and how that work. Also what is with that APT decoder, anyone else try it?

The APT-X100 algorithm is a pretty simple waveform based codec. It is a completely different audio compression coder from that used in the home theater version of DTS. But some of the same audio engineer guys in Ireland worked on both formats.

The DTS players have some proprietary hardware inside the machines to do the decoding process in real time. The WinAMP plug-in obviously does much of the same thing using some software tricks to get the decoding work without the expensive custom circuit boards found in a $6000 DTS machine.

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