A bit of a shock, but this information from Apple cleared up the question from NAB about why some media can't be optimised within FCPX.

Apple have published a Knowledge Base article indicating that that some formats cannot be optimised in Final Cut Pro X. If you cast your mind back to NAB this year, we were puzzled why the Sony PDZK-LT2 ingest plugin for FCPX wasn't allowing the XDCAM files to be optimised right after import. Now we know it will never happen. Good timing from Apple as yesterday we had the pleasure of a Sony member of staff here on the campus at FCP.co and yes you've guessed, we were talking formats, codecs and why XDCAM wasn't getting optimised.

We're a bit puzzled about this statement as having suffered the crashfest nightmare of using ProRes & XDCAM in the same FCP7 timeline, avoiding mixing I-frame and Long-GOP seemed a good idea. Maybe it is the power of FCPX under the hood or something technical with AV Foundation in the future that means optimising the files isn't a good idea. If we carry the argument one stage further, it means a large project made up of XDCAM and exported to ProRes will likely take a lot longer due to the conversion on export.

Very curious indeed. We have put an email into Apple to see if they can explain why (because we like to know these things) formats such as XDCAM don't need the conversion. In the meantime, here's the whole data from the article:

"Final Cut Pro X includes an option to "Create optimized media" which transcodes video to Apple ProRes 422. This can provide better performance during editing, faster render times with better image quality, and faster export. If the original camera format can be edited with good performance, this option is dimmed.

Native camera media formats that can be edited with good performance include:

  • HDV
  • DV

For these formats, the "Create optimized media" option is dimmed. The preferred workflow is to use the native camera media format for editing."

Additional Information