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Timecode Woes

Posted: Sat Sep 30, 2017 7:22 pm
by jarwady
Hi All,

I'm running Windows 10 and Digital Performer 9.5 64-bit.

I have a video clip I need to score with the following specs:

Frame Rate - 29.97 fps drop
Sample Rate - 48 kHz
Bit Depth - 16 bit

I open a new DP file and set my project settings to the above spec. I also make sure my transport is displaying measures on the left, and frames on the right. I have a MOTU Ultralite MK 4 and the Sample Rate on it is also set to 48 kHz.

I then import the video clip. The first thing I see in the video window is the first frame of the clip with burned in timecode that looks exactly like this:

00;00;00;00

This seems unusual as I would've expected it to look like this with 29.97 drop

00:00:00;00

However, the clip runs correctly and is indeed what I need to score. Now call me "old-fashioned" but when I'm using SMPTE I want my numbers to match! Meaning that when I scrub anywhere on the timeline and let go, I want the transport frames number to match the burned in timecode in the clip. Currently whenever I do this, Digital Performer is 1 frame ahead of the burned in timecode in the clip. This is consistent throughout the clip.

Questions:

1. Is it unrealistic to expect the numbers to match? Am I going Adrian Monk here?

2. Is there a way to offset my chunk to compensate for this? I have tried various permutations of setting the Chunk start time but with no success.

Now exploring alternatives, I've opened this file up in Logic Pro X on my Macbook Pro. Logic displays the frames and also the timecode bits. My current understanding is that there are 80 bits per frame (although I'm not sure how bits are affected with 29.97 drop). What I can tell you is that in Logic, when I advance by a single frame, the transport counter looks like this:

00:00:00;00.79

This seems to suggest that Digital Performer is rounding up to the nearest frame which would explain why when I advance a single frame in DP, the burned in timecode in the clip still says:

00;00;00;00

We can think of this as follows:

1 Frame in: ;00.79
2 Frames in: ;1.79
3 Frames in: ;2.79

etc.

Thus, DP is rounding so we get 1, 2, 3 frames in DP and 0, 1, 2 frames on the corresponding burned in timecode.

Questions: Why the deuce is a timecode bit dropping? If this is a known phenomenon, why doesn't DP compensate and give me matching SMPTE?

For me, this seems untenable. If I am off by a frame it will affect my timings, and if I can't compensate for that, then why am I using DP for my film scoring DAW?

I would think that 29.97 fps drop would be one of the more common video frame rates and that the issue I'm having should be easily solved (but more preferably compensated for by MOTU in the first place).

Please, any help you can provide here would be most appreciated. I really like DP and want to use it moving forward. However, such basic structural issues must first be solved. Thanks in advance.

-Jeff

Re: Timecode Woes

Posted: Sat Sep 30, 2017 7:44 pm
by MIDI Life Crisis
Also check SET MOVIE START TIME in the movie window by right clicking (Control click on a Mac and whatever that is on a PC). It's probably set correctly, but you might be able to adjust the discrepancy.

Re: Timecode Woes

Posted: Sat Sep 30, 2017 7:46 pm
by jarwady
Thanks for the reply, MIDI Life Crisis.

Here is a great opportunity for me to learn something - so I'm not sure how to set the movie start time back a frame when it starts at

00;00;00;00

Could you please advise? Much appreciated.

Re: Timecode Woes

Posted: Sat Sep 30, 2017 7:51 pm
by jarwady
In addendum to my original post, it looks like the bits run from 0 - 79 according to this article:

https://en.wikipedia.org/wiki/Linear_timecode

So given that I'm seeing ;00.79 in Logic Pro makes me thoroughly confused. Is ;01 shorthand for ;00.79? If so, why would the burned in timecode not round in the same manner that DP does?

Re: Timecode Woes

Posted: Sat Sep 30, 2017 7:54 pm
by Kurt Cowling
You can't... but you could pretend it says 01;00;00;00. Then you can set the chunk start back one frame. The hours field won't match between the burn in and DP, but that's better than being one frame off.

Re: Timecode Woes

Posted: Sat Sep 30, 2017 9:01 pm
by jarwady
Kurt,

That was the solution! Thank you!!

While I still have many unanswered questions about this experience, you provided me with a way to move forward. I sent a test to the producer and we are in sync. When I scrub, the frames are the same. I ended up setting the movie start time to:

00;59;59;29

Then I set the chunk start time to:

01:00:00;00

This put the chunk one frame ahead of the movie and compensated for the one frame difference. Thanks again, you really saved me here :)

Best,
Jeff

Re: Timecode Woes

Posted: Sat Sep 30, 2017 9:04 pm
by Kurt Cowling
No problem. Whoever burned the time code into the frame should've known to start it at 1 hour. Standard practice for exactly this reason.

Re: Timecode Woes

Posted: Sat Sep 30, 2017 9:07 pm
by jarwady
Kurt,

Interesting. It's oddly comforting that this is not an issue isolated to my circumstances. I'll pass your note along to my producer.

Re: Timecode Woes

Posted: Sat Sep 30, 2017 11:13 pm
by Kurt Cowling
That standard actually began back in the days when tape machines needed pre-roll in order to sync up. Also, what happens if they ask you to write two measure intro in front of what you've already done?

Re: Timecode Woes

Posted: Sun Oct 01, 2017 6:00 am
by jarwady
Kurt,

That makes so much sense. Thanks again for your help and insight. My producer and I are both better for it :)