I would like to let You know that I'm not insane and I know what I'm.
Couple days ago I copied my whole Lion installation to other Mac using SuperDuper and export from QuickTime X worked several times. Today after two exports it suddenly exported audio only.
So I tried to export same file that was successful earlier. It exported again successfully on this second Mac and also on previous one.
Difference is strange but obvious in QuickTime X inspector palette (doubled video track).
But QuickTime 7 doesn't see it that way:
These two files were exported from Final Cut Pro 7 with no known differences in sequence settings.
I have found difference. This unsuccessful file had unmodified parts of footage that didn't required re-encoding.
This successful file didn't have frames that were passed through'ed.
After selecting "Recompress All Frames" while exporting from Final Cut Pro I received file that had only one video track just as this successful one.
I was able to export this file from QuickTime X as H.264 without any problems.
This method is only workaround as it causes longer exports times when no reencoding is necesary.
I have the same problem.
Lion & QT X, video edited on FCS2.
Everything was working ok untill the day I only exported the audio from a video. Untill then, QT just exports audio.
I though my be reinstalling the application could be solved, but I cannot find where dowload it from.
I´ve tried installing the codecs also, but the problem remains.
¿Is there a sollution?
two years have passed since the original question...