What defines whether a filter can be made partial or not? E.g., none of the rotation filters can be made partial, so it's difficult to apply a rotation to a part of a video. It would be understandable if the filter would change the resolution, but when it doesn't then why can't you make them partial?
Any filters which operate on multiple input frames and therefore require caching as well as filters which modify timing cannot be made partial.
Well, the rotation filters don't use multiple input frames or caching, so they should be partializable. But they're not.
Rotation filter changes resolution, therefore it cannot be partialzed.
There are 3 rotation filters. 2 of them might change the resolution, but the OpenGl Rotate doesn't. None of them can be partialized.