My plugin usually displays its own progress bar when rendering, but when called to render each frame of a movie the progress bar can be annoying. I'd like to hide it if I know I am being called for a movie. Is there a way to detect in the code if this is the case, in a way that can be distinguished from a normal smart object, filter menu, or action call?
No, I don't believe there is any way to do that.
The API is abstracted so that the filter should not know it is being called from a smart filter or movie -- it should appear the same as being called from an action.
Okay, that makes sense. We only cared because we were spawning our own progress bar, and it was getting annoying with it popping up and going away with each frame of the movie. I rewrote the code to just skip our progress bar when being called from an action, and this improved the situation.