All this talk of super sampling has me looking for it, and when I right click on the video bus and apply video envelope I ony have two choices. even though under the display option I have all the boxes checked
1. from Menu Bar, click View Video Bus track
2. a new blank track called video should appear below all other tracks
3. right click in the header area of this video track, should see insert/remove envelope
4. from the selection pick Video Super Sample
5. A brown line appears similar to how other envelopes look
You may have to resize the the track and/or move down your other window panes to see the track and envelope fully. Now as with other envelopes right click to set points.