Weirdness from an exported QT

Hi all,

I'm checking my original sequence to make sure nothing has been changed from when I output my Quicktime that I gave to my sound re-recordist / mixer (I have placed the QT on top of the "original sequence" and applied a greyscale filter to the QT and cropped it so 1/2 of the screen is the QT and the other is the original sequence) I'm noticing that the QT I exported seems to be in and out of sync with the timeline (i.e. sometimes the picture is exactly where it should be and sometimes it's off).

When I investigated (going frame by frame) i noticed that the Quicktime that I exported skips frames and repeats frames throwing it in and out of sync with my timeline. At first I thought this might be a result of being from a Drop Frame sequence but on reading the FAQs I don't think that's the issue.

The problem now is that the entire audio was synced to that QT and I'm not sure what I can / should do about it.

Here are the deets on the wonky QT.

Sorenson Video 3 Decompressor, 480 x 360, Millions
16-bit Integer (Big Endian), Stereo (L R), 48.000 kHz

FPS 27.81
Data Size 4.26 GB
Data Rate 7,434.25 kbit/s
Current Size 480 x 360 pixels (Actual)

Okay in checking the FPS THAT doesn't seem kosher at all. WTF? Help.

John
FCP 7

Was the file an AVI?

> Sorenson Video 3 Decompressor, 480 x 360, Millions
> FPS 27.81

Okay, I'm assuming your information above is a bit obscure. I'm assuming that your exported QuickTime, the one going to your sound designer, is a Sorenson 3 file. If you did use a Sorenson 3 file directly in a timeline...yikes.

The frame rate shown in QuickTime is not accurate. Look at the clip's properties in FCP (COMMAND-9).

What are the original codec, frame rate and audio sample rate of the clip in the timeline? What are the Sequence codec, frame rate, audio sample rate?


www.derekmok.com

hi guys,

thanks for the quick reply. The sequence settings are drop frame, Uncompressed 10 bit SD. I performed the operation "command 9" on the ciip and it gives me mostly sequence information. Is this what you wanted? I did export Quicktime from an originally DV clip. The compression used was Sorenson Video 3. When in the sequence it says its frame rate is 29.97 fps.

So, you imported a mini DV file, dropped that in an uncompressed 10 bit sequence and then exported a sorenson Video 3 File via 'Using Quicktime Conversion' - is that correct?

Also, just checking - your original video was 29.97, right? Not 25?

Hi guys,

I'm sorry to have not been clear. Thanks for bearing with me. I shot and cut the film in DV. At the request of my sound re-recordist I exported a Quicktime from the the original DV sequence using the Sorenson video compressor (don't know why he requested that format). He used that clip as the reference video to which he edited the audio.

Part of the original sequence was archival footage shot on 8 mm and captured with a terrible telecine in DV. Disappointed with the original capture of this footage and Intending to send my colorist an SD output I had the 8 mm footage re-captured at a great post house. This re-capture was done frame by frame using 10 bit uncompressed SD.

I created a new sequence where I've "up-rezed" the original DV sequence to 10 bit and placed the re-captured 8 mm footage in the sequence. Now, intending to check the entire sequence to ensure there are no sync issues / that I've not accidentally moved anything around, I've placed my audio guy's reference Sorenson video output above my sequence / cropping the image so that it takes up half the frame. i'm using this method to check cut by cut whether anything has been moved by accident. What I'm discovering as I go frame by frame is that there are lots of sync issues and it seems to be the fault of the Sorenson video which appears to have skipped some frames duplicated others. So I'm having considerable difficulty verifying that the sequence is "unmodified".

Any ideas?

John

There are several potential problems with this workflow - the first that comes to mind is the frame rates.

What frame rates were all your originals? What frame rates was your DV export? Your 10 Bit Sequence? The Sorenson clip that you re-imported?

FCP will try to force things into the frame rate you specify in the sequence, but it won't do that great a job if they are too different, so it can add frames, skip frames and all kinds of messed up voodoo to make it work.

Could you use timecode on the Sorenson in QT to see if it matches the cut points on your new version?

Hi Jude,

My original DV tapes were recorded in drop-frame 30 fps (29.97 fps). The conversion to uncompressed SD maintained this frame rate. The sequence in which I'm working is also 29.97 fps. The only thing that's off is the Sorenson Video which (when I click on the clip outside of Final Cut and open the inspector) says it was encoded at 28.71 FPS). I didn't set it to this frame rate so I'm not sure why it says that.

I'm not sure what you mean by "Could you use timecode on the Sorenson in QT to see if it matches the cut points on your new version?".

John

Personally, I'd start from scratch.

First export a full-quality movie file (Export - QuickTime Movie, Current Settings). It will be a big file, but that's what you want. Check the FPS and audio sample rate in FCP (open the movie file into FCP, COMMAND-9) to make sure the frame rate is accurate. Then have your sound designer open that same movie file and check it against his audio sync, with you present, on his system. My bet would be that either there's something wrong with the Sorenson 3 file, or the sound designer's (Pro Tools?) session. You have to reduce the number of variables in the equation. And since we know nothing about your production, I'm not yet ruling out that your sound designer
screwed up with the sync to begin with. I've worked with a self-proclaimed "mixer" before who couldn't hear noise in the dialogue even when I could.


www.derekmok.com

Going to the sound designer with the new clip is the best idea.

What I meant, though, was opening the Sorenson AND the new version export in QT, then, using the timecode display at the bottom left of the Quicktime screen, seeing if the cut points match. The first time you hit one that doesn't, you know it's wrong.

Thanks guys for all your help.

John