Thanks for speedy reply.
Let me give you a little more of my concern: I am making 1920x1080 videos. Some customers get them in that form, others get chopdowns, usually 1280x720, sometimes 720x480.
That's on the output side, and I need to be able to control it.
On the input side, my sources are usually 1080p, either HD camera footage or screencaps. But for my next work, I also need frequent recourse to webcam footage, w/my webcam producing 720x480.
If I just import/edit my 720x480 source, I can't produce
any of my desired outputs, not 1920 or 1280 or 720. If I import a 1920x1080 source, I can produce all of them.
So. In the interim from last message, I tried some experiments.
I can create non-MP4 productions to 720 w/o demurral, or 1280 or 1920.
I went to a 1920-based pds I created in another part of the forest. I left just the initial title jpg and a split second of 1920 footage, then imported my webcam 720. It added to the timeline, was editable, and when I went to produce the full range of choices was present.
I then deleted the 1920 snippet. Still can create any range of outputs.
So. For the moment, I have a workaround. I can freely add/edit from the 720 sources
if I first add/edit a 1920 source.
Meanwhile, though, I don't like having problems I don't understand. I still want to know why the natural behavior, importing a 720 video and editing it, doesn't let me produce any of the desired outputs. If it's a bug, so be it, life goes on. If it's PEBChK, though, I'd like to know that, too[1].
Seeya,
GeePaw
[1] PEBChK -- standard service desk code for "Problem Exists Between Chair and Keyboard".