Often in previs setups, you have several "variations" of image/movie strips
for review, where the topmost one completely covers the others under it. VSE
rendering already had an optimization where if there's a fully opaque strip
that covers the whole screen, then the lower strips are skipped from
processing/rendering. However, it was not handling the case of non-fullscreen
strips (e.g. you'd have a Color strip near top & bottom for letterboxing, and
an opaque strip "in the middle").
This adds a simple "occluder tracking", and skips strips that are completely
covered by any single opaque strip that is above it (like outlined in #117790
task).
Playback of Gold previs between 1:42 and 1:55, on Windows/Ryzen5950X:
- Average frame time 28.5ms -> 23.8ms
- Median frame time 24.1ms -> 21.5ms
- Two slowest frames: 263->189ms, 194->178ms
Rendering the Gold previs movie: 325s -> 304s (93% of previous time)
Pull Request: https://projects.blender.org/blender/blender/pulls/118396
- enum class StripEarlyOut instead of raw integer defines
- SeqRenderState default initializer instead of seq_render_state_init
- Vector<Sequence*> instead of manually sized arrays of pointers
- some const to several function arguments
Pull Request: https://projects.blender.org/blender/blender/pulls/117829
