Does Maestro use drop-frame or non-drop frame timecode?

[tyee]

I'm just wondering about this because my recent project starts to have slight jerks in it after a period of time (not at the beginning) and the more I read about drop and non-drop timecode the more I think that may be my problem. Nothing in the Maestro manual talks about it as far as I can tell.

So if I'm authoring an edited DV tape with drop-frame timecode (that's what Vegas Video says DV is), and Maestro uses non-drop frame, would that cause slight jerkiness after a period of time?

Here's why I think this may be the problem --

In order to "synchronize" the clocks on the wall with the elapsed time counters in the edit system, video engineers developed drop-frame timecode, which works sorts of like a leap year in reverse. Two frame numbers are dropped or skipped every minute, except when the number of the minute ends in zero, such as minutes 00, 10, 20, 30, etc.

It is important to realize that the video frames themselves are not deleted. Only their numerical labels are affected.


tyee

[slk001]

In the past two months, I have used both timecode systems in Maestro. Lately, I have been using DROP-FRAME TC exclusively, but I have never seen a jerkiness like you mentioned. Your problem may be the way you are generating the DF flag. I use the "-drop_frame true" option in PULLDOWN to set mine.

Remember, that no frame really gets dropped - only the TIMING gets changed (corrected), so no jerkiness should every appear with the DROP-FRAME timecodes.

[tyee]

slk001

The latest versions of CCE have a DF checkbox so that's what I'm using. BTW, I just re-encoded with CCE using the DF checkbox and recompiled in Maestro and the problem is still there, but in different places. This is really weird to me. I'm not an expert but I like to dig and try to find the answer so I guess that will continue.

Maybe CCE is doing something wrong to this flag like you said, but it doesn't seem to make a difference in Maestro either way.

With drop or non-drop frame timecode on the video both versions were in sync right to the end of the 67 minute program, even though there was about 4 to 5 seconds difference between the video running time and the audio running time when using non-drop timecode imported into Maestro.

[slk001]

Why don't you use PULLDOWN after you encode with CCE. Is your encode at 23.976 or 29.97fps?

[tyee]

It's at 29.97. I just tried authoring again this time without any audio track, and the stutters are still there! so it looks like timecode may not be the problem. Maybe it's just glitches in the original .avi file. The problem is how do I view a .avi file in interlaced format on a computer. I ask this because I cannot see the stutters on my computer monitor because it's progressive of course.

Maybe I can view my edited interlaced 29.97fps .avi file by hooking up an external TV to my video card "S" or "composite" output, Yes??

tyee

[slk001]

Well, what was the original SOURCE material - FILM or NTSC? Or, is your DV shot at 24 or 30fps?

It's beginning to sound like you have a field order problem. DV is usually bottom field first.

Back to your original question, if you encode your video in DROP-FRAME timing, your audio (and subpictures) haev to be in this format. And if you encode your video in NON DROP-FRAME timing, your audio (and subpictures) also have to be in this format.

[tyee]

slk001

Originally posted by slk001
Well, what was the original SOURCE material - FILM or NTSC? Or, is your DV shot at 24 or 30fps?

My source is NTSC DV 29.97fps camcorder interlaced.


Quote -
Back to your original question, if you encode your video in DROP-FRAME timing, your audio (and subpictures) haev to be in this format. And if you encode your video in NON DROP-FRAME timing, your audio (and subpictures) also have to be in this format.

I've been wondering about this. It seems that the Maestro manual says basically that either your video and audio timecodes match or they don't. In my case, they don't. So in this case Maestro will, according to the manual, line up the first sample of audio with the first frame of video essentially ignoring both timecodes. Maybe this is the reason I don't have a sync problem.

When I have time to check I'll see if the original DV .avi has the stutters in it.

tyee