First off, if you want Flash’s .f4v files to work in FCP X, you need to change the extension to .mp4. So myfile.f4v becomes myfile.mp4
I’ve been doing some streaming lately with Ustream. It’s a decent platform, but I’m not particularly in love with it (and it’s expensive). Anyways, if you save the stream to a file, it saves it as a Flash Video file (.f4v). The file itself plays back fine. However, if you pull it into Premiere Pro for editing, adding graphics, etc., PPro can’t keep the audio in sync. Adobe… WTF? It’s your file format!
Final Cut Pro X does not have this problem. As mentioned, you need to change the file extension to .mp4, but otherwise it handles it beautifully.
Even if you pull the renamed file into Premiere, it still loses the audio sync. So it’s just a complete fail on Adobe’s part. FCP does a terrific job of handling this even on long programs like this 90 minute panel discussion.
Here’s the Final Cut Pro file, saved out to a Quicktime file and then uploaded to YouTube:
Here’s the Premiere Pro video, also saved out to Quicktime and uploaded. You’ll notice it starts out ok, but then quickly loses audio sync. This is typical in my tests. The longer the video the more out of sync it gets. In this 30 second example it’s not too out of sync, but it’s there.