Fixes a number of playback stuttering and general UI lag issues by setting all
background tasks to IdlePriority rather than LowPriority. While it was assumed
LowPriority tasks would always get scheduled below NormalPriority (e.g. main
thread) tasks, it turns out this is not always the case. If the background tasks
start consuming a lot of CPU cycles, the scheduler may use "dynamic scheduling"
to schedule them above the main thread regardless leading to UI lag. This is
apparently the case for all thread priorities apart from IdlePriority, which
is allegedly a special case where threads are *only* scheduled when other
threads aren't busy ensuring the main thread stays responsive.
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.
than overwritten on some platforms
Despite the fact we don't actually do any reading here, using
QFile::WriteOnly on its own will truncate the file to 0 bytes which is
undesirable. The documentation says QFile::ReadOnly, Append or NewOnly
will prevent this. NewOnly won't work and reads are unnecessary, so
Append was used initially. However on some platforms, Append will _only_
allow writing at the end of the file (ignoring the seek() function)
meaning bytes won't be written where they're meant to be (this behavior
happens on Linux and not on Windows, the platform discrepancy is likely
a Qt bug). Using ReadWrite instead, despite not reading anything,
prevents truncation and allows for writing not at the end of the file.
context
More intuitive code flow and allows the user to undock the viewer (which
forcibly destroys and recreates the context) and the viewer will handle
creation of the new texture in said new context.
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.
The workers run in separate threads meaning if any significant change is made
(e.g. parameters changing, or even closing the program), these workers may still
be mid-render. This is particularly problematic when closing since the nodes a
worker is rendering may be deleted mid-render. Render backends now have a
function that pauses the main thread (but starts a second event loop so the UI
isn't frozen) until the worker threads are all finished. This way, massive
changes can be made safely without race conditions.
We try to handle aspect ratios in metadata (e.g. stretching 1440x1080 videos
out to 1920x1080 when requested), and FFmpeg will usually return a 1/1
aspect ratio even if it can't determine an aspect ratio. However, as mentioned
in the documentation, sometimes it returns a 0/0 aspect ratio when it can't
determine an aspect ratio, which we didn't handle and would lead to the code
allocating a buffer with a 0px height. This commit handles both 1/1 and 0/0
aspect ratios in accordance with the FFmpeg documentation.
Reference: https://www.ffmpeg.org/doxygen/4.0/structAVFrame.html#a62f9c20541a83d37db7072126ff0060d
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.
By using one thread per logical CPU thread, we seemed to completely saturate
the CPU which would kill the performance of the main/GUI thread (despite the
other threads being low priority). We now use half of the logical threads, which
still sees good CPU usage and minimal performance impact while allowing the
main thread to respond to user actions.
A few commits ago, the render behavior was changed to only render within a
user-specified range of the playhead. This works well, but it would still
render from the start of the range (usually before the playhead) to the end,
meaning it couldn't keep up with the playhead as well as it should. This
commit prioritizes frames close to the playhead and renders outwards to
address this.
Previously we had no disk management whatsoever, so we cleared the cache on
every close just to prevent clogging up tester disk space. Now that we are
implementing disk management, there are better things to do on close regarding
disk cache. However, some users may still wish for the app to delete the cache
on close, so it's provided as an option.
itsmattkc