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» Film-Tech Forum   » Operations   » Film Handlers' Forum   » DTS track slow to start. (Page 1)

 
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Author Topic: DTS track slow to start.
Rob J. Buskop
Expert Film Handler

Posts: 105
From: Rotterdam, the Netherlands
Registered: Aug 2005


 - posted 08-07-2008 11:21 AM      Profile for Rob J. Buskop   Email Rob J. Buskop   Send New Private Message       Edit/Delete Post 
A while ago a lab printed a missing piece of entr'acte music for a film in our archive.The DTS timecode from Rl. nr. on the disc combined with SR analog track. So far so good. But when checking it out in DTS only (bypassing the opt. reader) it skipped about
4 seconds from the beginning of the music. So in DTS mode the sound came about 4 seconds after the orchestral piece had started.
Hereafter all was fine.
When laced through the optical reader as well, the first opening chords were there, whilst it was apparent that after a few seconds it switched over to DTS.
Could this have something to do with the spin up time of the disc or should there be some special timecode info in front of the actual code that relates to the start of the music?
The only thing I can think of is a time lag between the first info that's been read and the delivery. Any ideas on this? And
would there be a solution to get rid of the SR beginning and have the whole start in DTS as it would have worked before some
projectionist tore the original play-in off?
Any suggestions will be highly appreciated!
Thanks,
Rob.

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Chris Slycord
Film God

Posts: 2986
From: 퍼항시, 경상푹도, South Korea
Registered: Mar 2007


 - posted 08-07-2008 11:29 AM      Profile for Chris Slycord   Email Chris Slycord   Send New Private Message       Edit/Delete Post 
Sounds like the beginning has a bad/missing DTS time code, possibly.

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Darryl Spicer
Film God

Posts: 3250
From: Lexington, KY, USA
Registered: Dec 2000


 - posted 08-07-2008 11:35 AM      Profile for Darryl Spicer     Send New Private Message       Edit/Delete Post 
It sounds to me like the delay is caused by the DTS unit storing up to four seconds of information before kicking in so it can have that 4 seconds advance info for time code dropouts.

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Rob J. Buskop
Expert Film Handler

Posts: 105
From: Rotterdam, the Netherlands
Registered: Aug 2005


 - posted 08-07-2008 12:46 PM      Profile for Rob J. Buskop   Email Rob J. Buskop   Send New Private Message       Edit/Delete Post 
Thanks, guys. But it's not missing or poor coding. The green
light goes on and then it takes a little while.
I myself think about the DTS "waking up" and then it has to spin up to locate the position where it wants to be. Remains the question what to do about it or what to splice in front of the newly made footage..... or what..!

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Marco Giustini
Film God

Posts: 2496
From: Reading, UK
Registered: Nov 2007


 - posted 08-07-2008 01:54 PM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
Is the missing piece at the beginning of the reel? In my experience, if you start a movie in a point different from the reel head the DTS player will take few seconds to lock.

Or, the DTS can be in sleep mode. After 30 minutes the drives stop spinning and it takes about 2 seconds to be ready again.

Marco

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Brad Miller
Administrator

Posts: 17590
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 08-07-2008 02:33 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
Generally when I have seen this it is because the projectionist didn't cut the film at the "3" on the countdown, and instead cut at the "0" or at a visible frameline. It does take the dts a second to start playing, hence the "lead in" black from the leader shouldn't ever be cut off.

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Rob J. Buskop
Expert Film Handler

Posts: 105
From: Rotterdam, the Netherlands
Registered: Aug 2005


 - posted 08-07-2008 04:53 PM      Profile for Rob J. Buskop   Email Rob J. Buskop   Send New Private Message       Edit/Delete Post 
Hi Brad, well it should be something like that. The question
now is how to cure it in some cunning manner.
It seems to me that, following this line of thinking, something
should be spliced in ahead of the newly printed play in to get
the DTS system in a sort of "primed" position.
Sadly there's no original leader. Have checked if the ROM player
reacts to the 0 signal ----- code to start it spinning at least
but that does not happen. Anyway it's difficult to imagine that within this very short period of the first time code being read everything should react immediately. But....when you would put
the original reel on it would not show this slightly delayed start...So what can one do to activate the system just before the first time code is read?

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Marco Giustini
Film God

Posts: 2496
From: Reading, UK
Registered: Nov 2007


 - posted 08-07-2008 05:45 PM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
It's not an "activate the system" issue.
On my demo reel I have some scene from the last 007. The player starts few seconds late since the beginning of the reel is missing (I spliced only a part of the reel).
If it's not a "player idle" issue I think you cannot cure this.

Marco

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Bruce Hansen
Jedi Master Film Handler

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


 - posted 08-07-2008 06:10 PM      Profile for Bruce Hansen   Email Bruce Hansen   Send New Private Message       Edit/Delete Post 
If the original leader has been cut off and the DTS time code starts at "0" count down, that could be your problem. The player does not know what you are going to want to play, so when it sees the first bit of time code, it must go find that time code on the disc. This can take several seconds.

If the original leader has been cut off, try this, it may help a little: attach the leader from a trailer that has DTS time code on it, to the beginning of your film. This may give the DTS player a little "kick", so that it will find the time code you want faster.

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Marco Giustini
Film God

Posts: 2496
From: Reading, UK
Registered: Nov 2007


 - posted 08-07-2008 06:25 PM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
There should be something different at the beginning of the timecode. The Player has no problems at all locking as the splice run if you cut properly the leaders...

Try following Bruce's way, but be sure that the beginning of the trailer is not played back instead of the movie's start [Smile]

marco

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John Wilson
Film God

Posts: 5431
From: Sydney, Australia.
Registered: Dec 1999


 - posted 08-07-2008 06:35 PM      Profile for John Wilson   Email John Wilson   Send New Private Message       Edit/Delete Post 
Try putting a dts tag on the head and see if it runs from the start of your music then. If not, the time code's not there. If it is, then you can just switch into it after the tag has gone through.

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Blaine Young
Master Film Handler

Posts: 473
From: Kirkland, WA, USA
Registered: Sep 2006


 - posted 08-08-2008 12:24 AM      Profile for Blaine Young   Email Blaine Young   Send New Private Message       Edit/Delete Post 
If you can post an image of the first 3 or 4 frames of the film in question, we can determine what your first viable DTS frame is. That will give us an idea of how much film is missing. If the timecode is simply too far into the program, you will have to live with the first part playing in SR.

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Rob J. Buskop
Expert Film Handler

Posts: 105
From: Rotterdam, the Netherlands
Registered: Aug 2005


 - posted 08-08-2008 04:57 AM      Profile for Rob J. Buskop   Email Rob J. Buskop   Send New Private Message       Edit/Delete Post 
Thank you all for your greatly appreciated thoughts on this matter! I think Bruce's idea of putting a DTS tag in front is worth trying. Will report on the result.
The suggestion of posting pictures of the first frames with TC is probably not very enlightening because it's play-in music, so there are no frames. Everything is black, apart from the soundtrack. Anyway I'll try to add a picture...!
 -

Had to reduce the size to the absolute minimum, so what was nice nad clear does'nt make much sense anymore now..... Sorry.

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Blaine Young
Master Film Handler

Posts: 473
From: Kirkland, WA, USA
Registered: Sep 2006


 - posted 08-08-2008 11:58 AM      Profile for Blaine Young   Email Blaine Young   Send New Private Message       Edit/Delete Post 
Unfortunately that isn't as high a resolution as I need. A close-up of the soundtrack area with the DTS Timecode will help. The image area is not important for this.

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Warren Dewey
Film Handler

Posts: 28
From: monterey ca usa
Registered: Jan 2006


 - posted 08-09-2008 07:29 AM      Profile for Warren Dewey   Author's Homepage   Email Warren Dewey   Send New Private Message       Edit/Delete Post 
There is a similar problem with the 1998 restored Wizard of Oz we are playing now. There are no splices involved-- reel 1 opens with the silent "new" Warner Burbank Studios wavy aerial shot logo, fade out, then fade in the 1939 lion. The lion's roar cuts on about 2 seconds late, even though our dts usually locks up fairly quickly.

The print has SR and DD tracks from the leader, but the dts track does not start until the "new" section is almost faded out, about 2 feet before the lion. There are about 6 frames of white dashes, then code. You definitely get the feeling a buffer is filling up before the sound comes on (??)

If there originally was dts material before the first logo, like a tag or trailer, I suppose the buffer would be ready and start playing immediately-- but the time code would still be missing during the first logo. Not a big deal, I'll just play the lion analog. But is it possible this version can't be played correctly with dts?

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