View Full Version : Multicam Editing w/ HD (ProRes Proxy) Issues


Luc Nutter
July 28th, 2010, 10:37 PM
Greetings from Columbus. I love the site, I try to use it as much as I can, and I've learned a great deal from you all, so thank you very much!

I recently shot a concert for a friend with some HD cameras that recorded it in 1080P. I went home, did some basic editing, and it was essentially "wrapped." A couple weeks later I was thinking about the pros/cons of HD vs. SD for clients and had a crazy idea. Now I'm sure that I'm not the first person to think of this, but I was the first one that I knew at least....

I wanted to take the 1920x1080 pixel videos and create different "angles" out of the existing clip by grabbing 854x480 sections out of the master clip to give me enough clips to work with in FCP to create more of a "live concert" feel with all the cutting between angles. The 854x480 represents SD widescreen sequence pixel dimensions (square pixels). So I took my master clips (which were in ProRes 422) into MPEG Streamclip and transcoded them into Apple ProRes Proxy and used the crop tools at the bottom to take away 1066 pixels from the width and 600 pixels from the height to leave me with 854x480 (this took some trial and error and a lot of pressing on the "preview" button). I was able to get 6 unique angles out of the two original angles, and I put all of these clips in a folder on a secondary internal drive in my Mac Pro to eliminate any problems that might be caused from using an external drive.

Once I had those clips, I imported them all into FCP, assigned them angles, and created a multiclip using their in points. I created a new sequence, dragged the multipclip into the sequence, when asked if I wanted to copy the clip settings to use as the sequence settings I said "yes." Then I double-clicked on my multiclip (which made it open up in the viewer), I changed my sync to "open," and my viewer to 9-up.

When I hit play in the timeline, the canvas shows the current video stream full screen with no problem, and the 6 video feeds are all showing in the viewer, but they aren't moving at all. When I hit the space bar to stop in the timeline, all 6 angles show the new current frame. So I'm now wondering if my computer just can't handle all of the feeds at once....? If I double-click on the clip and hit play in the viewer, only one feed plays, and it plays fullscreen. If I scrub through the footage in the viewer, all 6 steams keep up no problem....

All the clips are spec'd out as follows: Frame Size: 854 x 480; Vid Rate: 29.97; Compressor: ProRes 422 (proxy); Date Rate: Varies between 1.5 MB/s and 2.0 MB/s; Aud Rate: 48.0 KHz; Aud Format: 16-bit Integer; Pixel Aspect: Square; Field Dominance: None; Angle: each clip is unique from 1-6

Computer Specs: 2 x 2.26 GHz Quad-Core Intel Xeon, 6 GB 1066 MHz DDR3, OS 10.6.2, FCP 7.0.1

With the steams coming in with such a low data rate, and the computer having quite a bit of "beef" to handle such data rates, I'm thoroughly confused as to why I can't edit these clips as a multiclip.

Many thanks in advance to the brilliant minds that will hopefully help me solve my problem.

Cheers.

Luc Nutter
August 2nd, 2010, 04:24 PM
Does anybody know what the issues might be with this? Is the data rate too high for my computer to handle?

Dave Partington
August 3rd, 2010, 12:50 PM
Are these coming from a single HDD? Your HDD may be having trouble dancing between all the different files. Scrubbing is not the same as requiring a sustained data rate. Trying getting an HDD raid set up and you may be surprised how much difference it will make.

Luc Nutter
August 9th, 2010, 11:00 AM
I will definitely look into something like that. If that what it comes to, I'm eager to look at my options. Still don't understand how so many other people talk about having no problems with their multicam setups....

Thanks for the reply.