I tried to contol V on the seleted video clip and video animation came up... then I selected composition: opacity and the only thing that happened when I clicked on the retangle box to the right of composition: opacity was that the timeline lengthened. I never saw a black opacity bar. What am I not doing correctly.
iMac, Mac OS X (10.7.2)
What you are describing is for a Video Fade not an Audio one.
Do not click the small dark rectangle.
Double-click anywhere inside the light blue Compositing:Opacity area and it will enlarge itself and allow you to adjust the opacity line.
To add keyframes, position the playhead and press alt-K (or Option-K).
If it's Audio Fades you want, position your cursor over the audio portion of a clip and you will see a tiny blob appear at the beginning and end of the audio in that clip.
These "blobs" are Audio Fade Handles.
To fade in simply grab the handle at the start of the clip and drag it a few seconds along the timeline.
To fade out, grab the handle at the end of the clip and drag it a few seconds towards the start.
final cut pro x... audio fade
