Quicktime Video Syncronization...

[Measuring Man]

When you create a 29.97 frame quicktime video using a semi-pro capture card like a Miro DC-30+ or Aurora Fuse you create a MJPEG video. I'm aware of how key frames work etc...and video compression....My question is....

Ift he video deck playing the original video is house synced, and the card is locking to the video in fine, howecome some movies drift in the timeline? Does protools lock quicktime frames to frames on it's timeline or is the video freewheeling even in protools?

For instance.. I capture video and spot it's first frame to that frame in protools. Over the course of an hour frames are starting about 6-7 subframes ahead or behind the frame on the Pro Tools timelines. This appears to me like the quicktime video is freewheeling? Is this the case or does Pro Tools take each frame and line it up and I'm just doing something stupid/wrong?

I ask this because if my audio is house synced but my quicktime playback isn't this could, under worst case circumstances, make my video out while the audio is in? Am I being to picky?

Side question...Has anyone had these drit problems with videos captured by the Canopus ADC100. I'm setting up a side fascility and might not be house synced right away. So if Pro Tools and quicktime frame lock I wouldn't be worried for the kind of small editing it would be doing?...

That's probably enough for one post [img]images/icons/smile.gif[/img]

Measuring Man

[Rail Jon Rogut]

If you're video referenced, and your pull down options are correct.. and the video's been conformed correctly.. there shouldn't be any synch issues with the DC30+... I've used it with 15-20 minute reels without any problems.

Rail

[Philthy]

What are you using to capture- Imovie has been known to drop frames- final cut works better.

[Boom Chic]

I hate to be simple, but here goes: 29.97 drop or non drop?

[Fokke van Saane]

There is a thread on this wich i started two months ago. I still haven't found what is the problem here and how to solve it.

ProTools movie a-sync
Open the created movie in QT player. Open movie info (apple-J) select video and frame rate, play the movie and see how it 'freewheels'. Here it is between 24.78 and 25.33 FPS where it should be 25 FPS (PAL). Isn't that funny?

There is a drift somewhere and everybody is quiet about it. That usually means there is a big problem in the software. There was no satisfying reply from Digidesign about it.

I use a Canopus and used the Miro DC30 before. Both have the drift/freewheel.

Fokke van Saane Amsterdam Holland Europe

[mostlypost]

I experience the same thing as "soft" sync in DV quicktimes at 29.97 OR 30fps rendered directly from Avid quicktimes. I don't capture from video. I convert in Final Cut Pro. If I convert to 24fps DV (the same frame rate as the Avid output) everything is very solid, but if I render the Quicktimes that ProTools can pull down on the dubbing stage, sync is very minutely rubbery, not drifting off, but sort of slewing (very minutely) around.

The weird thing is, Quicktime player shows the same "bouncing" frame rates in 29.97 and 24, but for some reason the 24 looks perfect. Oh well.

[trakbytes]

Well, I've been using a Miro DC 30 for years, and have never experienced drift problems. If I spot the movie in ProTools (in grid mode/frames), I can click in any area, go to sub frames and nudge back, and the picture and ProTools will line up every time. It doesn't seem to matter whether the picture is locked to house sync or not, as I get the same results at work with house sync or at home with a non-locked VHS deck.

I capture with Premier 5.1c. There is a "conform movie" option which determines whether the movie is conformed to 29.97 or 30 fps (for pull-down work). Perhaps this takes care of lining up the frame edges. You can also use this function to conform an already captured movie if it's frame rate is suspect.

I have not used the Miro with PAL, so maybe something different is going on there, but it seems the capture software may be suspect with those experiencing drift.

rcm

[ChrisMac]

To anyone using DV picture with Protools.
Try opening a movie you have captured in Quicktime Player. Open the "Movie info" window (so you can see it and the movie at the same time) and play back the movie. The info window will show the playback frame rate. Let us know what you see.

[Measuring Man]

I don't find any drift or anything, I'm onl;y talking about a few sub frames by the end of the movie, ie about 1 hour. The little drift I'm talking about is pretty tiny, no matter what frame rate, 29, 30pd or what have you. I know all the differences...

What I notice is that it goes out very minutely over the couse of an hour. So if it's out by 7 sub frames at 1 hour it
s only about 2 sub-frames out at 15minutes. In the quitime info it reads true 29.97. I have had bad dig's that reported 29.96 or worse, but that was a different hardware issue in the end.

Presumeing that eash frame was capured accurately, wouldn't Pro Tools, Quicktime and the video hardware make sure each frame was played at the time it supposed to play at and not therefore see drift on the PT timeline. I know, with compression that there are keyframes involved etc..but a frame is a frame is a frames is it not?

[jmanc]

[QUOTE]Originally posted by Measuring Man:
[QB] When you create a 29.97 frame quicktime video using a semi-pro capture card like a Miro DC-30+ or Aurora Fuse you create a MJPEG video. I'm aware of how key frames work etc...and video compression....My question is....

Ift he video deck playing the original video is house synced, and the card is locking to the video in fine, howecome some movies drift in the timeline? Does protools lock quicktime frames to frames on it's timeline or is the video freewheeling even in protools?

For instance.. I capture video and spot it's first frame to that frame in protools. Over the course of an hour frames are starting about 6-7 subframes ahead or behind the frame on the Pro Tools timelines. This appears to me like the quicktime video is freewheeling? Is this the case or does Pro Tools take each frame and line it up and I'm just doing something stupid/wrong?


Assuming that your choice of timecode is correct your problem lies in the spotting of the video. With Adobe Premiere when you capture the video, it is captured usually without machine control. This will cause the very first frame of video to be a bit suspect. This is because each frame is based on 80 subframes. When you manually capture video, 99 percent of the time you'll capture within that 80 subframe. In other wards, for first frame of video it won't be at frame 1 subframe 1 but rather at frame 1 subframe 25.
This is not a problem and can be easily fixed by spotting your video based on first frame of program start not of video. For example, if you started capturing at 59:50:00 and first frame of program starts at 01:00:00:00, then spot your quicktime from 01:00:00:00 timecode.

Hope this helps..