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.
An earlier commit addressed faulty TaskViewItem ordering by changing
insertWidget to addWidget. Turns out this was the wrong strategy since the
insert was used to get widgets above the stretch. The correct strategy is
using insert(count()-1) instead of insert(0)
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.
Nouveau has poor compatibility with Olive (and most other graphically intensive
applications). For user benefit, we throw a warning messagebox if we detect the
user is using Nouveau.
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.
itsmattkc