Rendered timeline transcoding on export

Hi all,

Here's a newb question from a longtime user. I have a timeline that has material shot on a C300 - XF MPEG. I did not optimize the media on import. Once the timeline was all locked, I rendered all. The project was set to ProRes 422 HG. All the shots were green screen, and keyed with the Primatte keyer. So every shot was rendered. I'm assuming all the rendering was to the project codec ProRes 422. It was a 10 minute project, so it took a fair amount of time to render, even on my MacPro w/ D700 graphics.

Question is - since I rendered the timeline, why does it seem that I'm rendering it all again even though I am exporting to a ProRes 422 HQ master file?

Can anyone clarify the best practice to keep the time to export down?

Thanks!

Bill

Export will take a long time for complex, ProRes HQ. That's simply a ton of data to write out. Having a rendered timeline can sometimes help cut export times down. BUT, you also waste time waiting for the render. It takes more time to 1- render timeline, 2- export, than it does to simply 1- export and be done. We've done a lot of trials on this at our TV station.

Not a whole lot you can do, your export time is your export time. ProRes HQ422 is a ton of data. Lots of keying adds to export time. That's just how it is.

To be clear, you are exporting straight from FCPX, not through Compressor, and before export there are no orange render bars on the timeline?

If so, I normally wouldn't expect it to re-render before export. However it seems that FCPX errs on the side of caution when rendering. Normally you don't notice this if the effect is fast, but for a computationally-intensive effect like Neat Video, you often think "why is it re-rendering?".

My first suggestion would be to selectively turn off effects (inc'l Primatte Keyer), render the timeline, then export it and see if it's still slow. You might be able to track down if it's an effect causing this and which one. You could probably do this with a smaller sample project to get faster turnaround on the tests.

If the tests point to Primatte Keyer, then you could observe the CPU and GPU behavior using iStat Menus. E.g, is it using all CPUs, or does it show evidence of being single-threaded on one CPU? Is it using any GPU resources? Some plugins like Neat Video have user-adjustable settings for rendering on either the CPU, GPU or both. Just because you have D700 GPUs doesn't mean those are being used.