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Posted by Dave Ganoe (Member # 53) on 01-03-2001, 07:00 AM:
Would someone explain what the difference is in the DTS discs. Why do some movies come with only 6track A and other with both A and B? Is is possible to play a dts disc back on a computer cdrom drive? THanks.
Posted by Christos Mitsakis (Member # 143) on 01-03-2001, 07:47 AM:
Each DTS disk can handle 90 minutes of sound data. For a film under 90 minutes one disc is enough (Disc A). For more than 90 minutes the data is spread into two discs (Disc A and B).With a computer you can read the contents of the DTS CDrom but you can't play it, unless you have software that bypasses the print's ID No, generates time code info and ofcourse does the decoding of the data stream. You also need a sound card with outputs for six channels.
If I am not mistaken in an older post here at Film-Tech someone refers to a program that can decode two channels at a time (correct me if I am wrong).
Happy New Year to All Film-Techers 
Christos.
Posted by Aaron Sisemore (Member # 145) on 01-03-2001, 11:20 AM:
You'd also need the proprietary DTS playback hardware to play a disk on a standard PC-Aaron
Posted by Torben Simonsen (Member # 555) on 01-03-2001, 06:19 PM:
Yes, if you want to play back the files on a DTS cdrom in real time, you will need the special board with the APT-X100 decoder chips.But, if you were able to get your hands on the specifications of the file format for the DTS audio files and the APT-X100 codec, I guess it would be quite possible to write a program to convert the files into a standard pc format like "wav" (or mp3 or whatever). I don't know if anyone has already done this. The APT-X100 codec is in fact reasonably simple compared to AC3, so making a conversion program ought to be quite doable if you have the required information.
-- Torben.
Posted by Karen Hultgren (Member # 395) on 01-03-2001, 06:29 PM:
If a movie is over 90 minutes long, it's soundtrack is split into 2 discs: one "A" and one "B". Some reels are on one disc and other reels are on the other. You cannot play discs using a computer. All you can do is look at the files. You must use DTS timecode and a DTS player to play the discs.Karen at DTS
Posted by Darryl Spicer (Member # 711) on 01-03-2001, 07:28 PM:
I do believe that the dts discs will hol mor than 90 minutes. Dracula 2000 is only 99 mins. long and has only one disc and Titanic was 3 hrs 16 mins. long and only used two discs so I would say they must hold around a 100 minutes before you need another disc.
Posted by Brad Miller (Member # 2) on 01-03-2001, 07:40 PM:
That's more accurate. I think at one point someone said that a dts disc could hold right at 100 minutes, meaning 3 hours 20 minutes total playing time for a 2 disc movie. However, most studios want their attached trailers recorded onto the feature discs so that eats up space and I think this is why generally people just say "over 90 minutes" or "under 90 minutes".Titanic must've been fun, as I noticed it was not a simple reels 1-5 on one disc and reels 6-10 on the other disc. It alternated between reels. Apparently it was the only way to cram that 3 hour and 16 minute movie onto 2 discs...but hey it worked!
Posted by Jesse Skeen (Member # 586) on 01-04-2001, 02:20 AM:
"The Mask of Zorro" also switched between both discs that way, and I know there have been a few others. The lights on the new DTS systems make it harder to tell which drive is working though.
Posted by Adam Martin (Member # 641) on 01-04-2001, 09:48 AM:
I seem to recall that the disc time was so tight on Titanic that the timecode didn't start 'til after the distributor logo.
Posted by Karen Hultgren (Member # 395) on 01-05-2001, 04:05 PM:
When I say 90-minutes per disc, that is a generality. It has more to do with the size of the file. There is one file per reel. Most reels are 20 minutes long. And, IN GENERAL, one disc holds 90 minutes.Karen at DTS