[Wrangler note: this thread was split off of the discussion begun here.]

If I were designing it for COM, I'd have it interface only one frame at a time. One frame of video can easily be stored in memory as a device-independent-bitmap. I'd let Photoshop do the editing and store it as a new composite layer so that the original is intact. Trust me, it really would be simple and quite feasible to program (if you know all the set-up code, of course.)

I can't figure why Premier and Photoshop don't have that sort of synergy. My only guess is because they both work exactly the same as their Mac counterparts, and I don't think MacOS is capable of this sort of functionality (at least I've never heard of anything like COM automation on the Mac side).

If I were designing it for COM, I'd have it interface only one frame at a time.
...but how would this change actually get saved to disk ??
Premiere/Vegas/MSP ... really any NLE ... don't actually change the video files in tracks, just picks up required portions.

If you edit in some other app, that app would still need some way to support writing down to the original video file, which is also something that you generally want to avoid. You'd need a solution that saved the "paint" to something accessable from within the video editor project.

Just being devil's advocate. Maybe by the end of this exchange, you'll have a solid spec to go out and write your own rotoscope module for Premiere or Vegas. ;)

ACTUALLY!!!
You might be able to write a "filter" plugin that allowed for rotoscoping !!!
Filters are usually passed one frame at a time via memory, and have access to pointers to adjacent frames.

Mmmmmmm.

Have fun. :)

"...but how would this change actually get saved to disk "

Here's the process I would use.

1) User initiates drawing sequence
2) First frame is sent to paint software as DIB
3) Paint software is used to change the frame as desired
4) If exit or advance next frame, send new frame to NLE
5) NLE decides what to do with new frame - either overwrite old one, or save it as a new composite layer on a new track
6) If advance to next frame, go back to 2. Otherwise we're done.

Of course this would all be seamless to the user, because in the ideal Automation setting, when the frame is accessed for editing the Photoshop toolbar would come up and you would just draw right on the video preview pane.

Is there a Vegas filter SDK? It's a remote possibility I might toy with something like that. Problem is though I don't think Photoshop opens itself up to automation. Only MS products tend to do that. So I'd have to design my own drawing tools, and of course could never do as well as Photoshop.

"The Gimp" is an open source answer to Photoshop, so you might be able to lift some code from there to get started.
I seem to remember people talking about a .NET scripting link in Vegas.

I've been programming a few plugins for Media Studio Pro in C. Photoshop, AE, Premiere all have some kind of open SDK. I'd be pretty surprised if something similar wasn't available for Vegas.

Have fun.

I'm not sure COM would actually be the best approach for such
a system due to the installation hassles, performance loss and
security problems. Not to mention compatability with 9x systems
and other systems like the Mac.

That's the reason I think why Premiere / Photoshop / AE aren't
using such a system. Vegas for example does have a COM and
.NET layer available where the former is not supported for end
use.

Ofcourse you can argue why there isn't a better interface indeed,
especially between the Adobe products.