Apple Compressor has always been a mystery to me. Sometimes it takes forever to transcode, but when I’m in the middle of a job I don’t have time to figure out why. I just plan my workday to transcode overnight and hope nothing crashes at 4am.
So I took some time today and did some tests with a 90 second clip from FCP7. Send to Compressor 3 and transcode to H.264/720p took 09:14 with a lot of other open programs on my 8 Core Mac Pro — 6.15 times the length of the clip.
After restarting and having only FCP7 and Compressor 3 on, same file took 08:54
Saving the Compressor 3 settings and reopening with Compressor 4 with Qmaster on (7 instances) yielded 09:01 — Seven seconds worse than Compressor 3 without Qmaster (I’ve never been able to get Qmaster to work with Compressor 3 — another story).
Next I went back to FCP7 and Exported a QuickTime file with current settings, saved as a self-contained movie. It took 00:33 to export, or about 1/3 of the length of the clip.
Transcoded the file with Compressor 4 with Qmaster on. 03:15
Transcoded with Compressor 3 without Qmaster: 03:07
So the best workflow for me right now is:
1. FCP 7: Export QuickTime file with current settings. Turn off FCP and any other open programs
2. Transcode file with Compressor 3
This yields a total transcode time of about 2.5X length of the clip, so a one hour video should take 2.5 hours to transcode.
Update: A one hour clip took 02:40:30 to create the QT file and transcode. A lot better than before. But I’m going to look into hardware acceleration.