functions
Indexing is a lengthy process and had a high chance of getting RenderWorkers
stuck doing it rather than being responsive to cache requests. This commit
introduces a system where workers never index media, but instead signal that
media is not ready to their RenderBackends which ensure that the media gets
indexed and re-queues the affected frames when those indexes are ready.
Previously, FFmpeg decoders needed to wait for the initial index to finish
before they could retrieve frames. Now they can retrieve frames while the
index is occurring, provided the appropriate frame has already been indexed (if
not, the retrieve will need to wait still).
Our renderer system is already heavily multithreaded and prioritized to keep the
main thread active. As a result, FFmpeg receives little benefits from being
multithreaded and is actually detrimental to our main thread as it hasn't been
prioritized to keep the main thread as active as possible.
unexpected data
When "probing" footage, Olive runs it past all of its decoders until one
responds that it can decode this file. However this caused issues when some
OIIO decoders would erroneously pick up incompatible files, try to read them
and segfault the entire app (notable OpenJPEG with MPEG-4 and RLA with WAVE
audio). We now use the file extension to check with OIIO if it "should" be
compatible before actually testing if it is.
This is not a "perfect" solution (i.e. someone could recreate the segfault by
renaming an MPEG-4 file to an image extension like .JPG), but is probably as
much as can be done Olive-side and should filter out all segfaults under normal
circumstances.
OIIO 2.x uses std::unique_ptr while 1.x uses raw pointers. Olive can now handle
both, manually destroying the raw pointers when necessary if running on OIIO
1.x.
Implementation isn't perfect yet, viewer/renderer doesn't update yet when
the preference is changed so a sequence needs to be re-opened for the change to
take effect.
itsmattkc