-
interlacing problem on exports from Avid
I have a client editing on Avid that is exporting movies for me to encode and author to DVD. The footage was shot on MiniDV and exported as a QT Animation.
Here is a sample clip:
https://constantnow.com/anderson/cardio_test.movIf you go frame by frame through the clip, you’ll see that every 4 frames or so, the video gives a bad field problem, especially during motion. What’s going on here and how do I get the client to correct the export? The footage seems fine when itss in the Avid timeline, its on export that the problem crops up. They have tried every possible field setting in the Avid on export, to no avail.
We even dug out our old copy of Automatic Duck, imported an OMF timeline and can go through the unrendered timeline and don’t see the problem until we render it and it appears.
David C Anderson
ConstantNow -
4 Replies
-
This footage was shot at 24 or 23.98. What you are seeing is the B/C and C/D frames of a 3:2 telecine cadence. You will notice that you have 2 “interlaced” frames per every 5 frame block within a cut.
Your real problem is that the telecine was not reversed before it was cut. In the clip you provided at every cut a new cadence pattern starts.
The only thing I know that can correct broken telecine cadences is the Snell & Wilcox Ukon. This would require you to play the footage via SDI into the Ukon and then capture the clean reversed telecine SDI on the other end. Not to mention the rental on the Ukon. Perhaps someone else knows of a software cadence corrector. Unless you breakup the edit to its individual clips, apps like After Effects will do nothing for you.
I would have the Avid folks try deinterlacing the project when exporting the QT and see if that gets you exceptable results.
In the future the Avid guys have got to reverse the telecine when they capture 24 or 23.98 the footage. Then they could send you a 23.98 clip which is the ideal frame rate for DVD encoding.
Sorry you have to go through this.
-
Hi,
Joe’s filter have a Frame Rate Adjuster that I don’t know if could helps you. In the Beta filters.
rafaelPPC G5 2x2Gh 4GbRAM/BlackMagic SD/PMBP 17″Core2Duo 4GbRAM
JVC DTV-17″/FCS2/AE CS3/COMBUSTION/SHAKE -
I actually spoke to the DP that shot it and he swears he shot standard 4X3, 29.97 interlaced video. Could something like digitizing the footage to the Avid using a preset to 23.98? Does that even make any sense?
David C Anderson
ConstantNow -
Unfortunately the footage tells a different story. To answer your question there is no working way to take native NTSC 29.97 footage and make it 23.98. If they tried it would look ghastly.
Things could have been worse the shoot could’ve had one camera shooting 24 and the others shooting 29.97.
But if these videos are direct to DVD 23.98 would be the preferred format. Post just needs to edit in 23.98. Another option would be to do the Avid equivalent of make offline project with 23.98 settings and capture the footage again this time reversing the telecine. They would have to go through the edit and check for black frames and other timing changes. But that takes time and we all know what time is.
My guess as to why the Avid folks didn’t see the problem is that they are watching it on a CRT.
Reply to this Discussion! Login or Sign Up