Often times errors will make it difficult to use Compressor strait out of your Final Cut Pro file, so exporting as a QuickTime file and then compressing it may be the answer.
Final Cut Failure
Though Final Cut Pro is often a reliable program, a cluttered media management job or corrupted video can often make it difficult to use. There are many cases when random errors will not allow Final Cut Pro to stay open for extended periods of time, especially not long enough to use Compressor for standard DVD or distribution compression. In these cases you may have to export as a QuickTime file and then use compressor to get it to the appropriate size and format.
This is a simple way of compressing, and may even be faster than the standard in many cases. When attempting to export in Final Cut Pro go to Export to a QuickTime Movie instead of Export Using Compressor. From here it will write the audio and video, and then make a high quality QuickTime movie file out of it. Now you simply right click that file and select the “Open With…" option and select Compressor.
From this point it is very similar to any way you would compress a standard Final Cut file. Select your MPEG setting, if it is for a DVD, or whatever specific characteristic you would like. Drag and drop them into the job window at the top left hand side of the display and then set the target destination up in the task bar. What will be different about compressing a video that has already been fully exported is that you will actually be able to see the video if wanted in Compressor. This can be useful to see exactly how much quality is lost during compression. The loss in quality should be comparable to compressing strait out of the Final Cut Pro file.
The QuickTime compression is not just good for exporting from Final Cut Pro but really compressing any QuickTime file as to put it on a DVD or other device, such as an iPod. When you are having trouble with compressing your editing file this is a good way to bypass one of the more difficult processes. Keep this method in mind as both an alternative and new possible standard way of using Compressor.