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  #1  
Old 12-22-2002, 11:08 AM
raywong raywong is offline
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Default Please help me keep my job!

I have a movie project due in 10 days and I can't even get started yet. I did not sleep last 2 nights trying everything to solve this problem.
I use Cubase for midi, and record them to PTLE on a seperate G4. It doesn't matter which one to be the MTC master, the timing is slopy. I have to manully move each recorded audio tracks left or right up to 300 samples because they are sometimes early and sometimes late. It is not the drifting, tempo seems accurate enough. Just bad trigger start time. I am running out of time, and I'll end up with slopy timming and everyone will know I ruin the movie and never hire me again. Any suggestion please!
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  #2  
Old 12-22-2002, 11:12 AM
Hazy Hill Hazy Hill is offline
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Default Re: Please help me keep my job!

Ray,

Do you lock the two G4s to a video deck via MTC and some kind of syncronizer?

Or do you lock your master DAW (say Cubase) to a QT copy of movie on the same computer as your master DAW and then lock Pro Tools to Cubase via MTC?
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  #3  
Old 12-22-2002, 11:22 AM
Rail Jon Rogut Rail Jon Rogut is offline
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Default Re: Please help me keep my job!

MIDI is only quarter frame accurate to begin with.. so allow for that much timing slop.

What sounds like your problem tho' is that you haven't tied the two systems together with any clock information.. just MTC which is positional info. You need to feed a digital clock from the source machne to the slave machine, and have the slave machine clock to the incoming digital clock, be that SPDIF, 1x or 256x word clock or ADAT lightpipe.

Rail
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  #4  
Old 12-22-2002, 07:35 PM
raywong raywong is offline
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Default Re: Please help me keep my job!

Thanks for the advice!!
I have a Miro DC30 on the Cubase G3, for capturing QT movies.
I have to sumit my work in as PT multi track because they are doing Dolby.
I will now try to link up the digi001 and cubase via SPDIF, setup Cubase to send out audio clock and PTLE to recieve audio clock and follow. Am I missing anything?
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  #5  
Old 12-22-2002, 08:19 PM
Rail Jon Rogut Rail Jon Rogut is offline
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Default Re: Please help me keep my job!

That sounds about right.. also if you're drifting from picture.. make sure that you conformed the movie in Premiere to the right SMPTE frame rate (same as the session).

In my experience, I've had to use pull down tho' to get sync 100% right (which isn't available in LE).

Rail
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Old 12-23-2002, 12:26 AM
Tex Tiles Tex Tiles is offline
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Default Re: Please help me keep my job!

unfortunately that is the spec for midi time code. there is a built in slop, usualy 5 to 10 milliseconds, but sometimes more. sorry dude. try dumping it all into ptle and use a quicktime movie to sync to with smpte, and then do a stereo mix plus smpte on a 3rd channel. that would maintain sync for you.
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  #7  
Old 12-23-2002, 03:21 AM
raywong raywong is offline
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Default Re: Please help me keep my job!

No luck! I already try to link the two computers by audio clock via SPIDF. I don't think I have drifting, but the track start time is really bad. I still have to move each tracks slightly.
Would buying a MOTU midi time piece AV do any improvment?
Thanks for all advice.
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  #8  
Old 12-23-2002, 11:58 AM
Rail Jon Rogut Rail Jon Rogut is offline
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Default Re: Please help me keep my job!

It sounds to me that you're just dealing with MIDI slop - 1/4 frame accuracy.. which is about 120th of a second or 8.3 msecs.

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Old 12-24-2002, 05:38 AM
raywong raywong is offline
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Default Re: Please help me keep my job!

8.3msec?
There are about 300-400 samples of slop between each tracks. Is that equivalent to 8.3 msec?
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  #10  
Old 12-24-2002, 10:40 AM
Rail Jon Rogut Rail Jon Rogut is offline
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Default Re: Please help me keep my job!

Do the math:

30 frames per second - 1 second at 44.1kHz is 44100 samples...

44100 samples takes the same time as 30 frames

So,

44100/30 = number of samples for 1 frame = 1470 samples.

Now, a quarter frame would then take 1470/4 samples = 367 samples.

Rail
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