So I've been running into some issues when trying to speed up a GoPro timelapse in FCP7. I use MPEG S/C to convert all my raws to ProRes422 and all the sequence settings match. Whenever I try to render it let alone even play the clip it gives me a "General Error" message.
Is the file too large to handle maybe? I'm trying to speed it up as quickly as I can so maybe that's an issue.
You don't really say what you're doing to the clip in FCP. It would be very helpful to know that. Also: what was the original frame rate on the GoPro clip?
If there's a possibility of re-shooting, you might want to use the GoPro timelapse feature where it shoots a still image after a set amount of time, creating an image sequence. It might be easier to work with in a different application, like Motion: massage it there, and then render out a clip for use in FCP.
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA