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.
The import function was written early on in the rewrite as a multithreaded
background task that was considered somewhat flawed. While it worked for the
most part, there were possibilities of race conditions that could have
potentially been fatal, particularly since media could theoretically be
deleted while the import/probe tasks were running in the background.
With the save/load functions coming in, it became even more complicated as
projects may include metadata about the footage that can't be implemented
easily when the footage is imported/probed in the background. Making importing
a modal task fixes all of these issues, it's still done in a background thread
to not hang the GUI thread, but the GUI thread can be briefly "paused" in a
user friendly way so that all these functions can be safer.
We use Qt's built in zlib compression on the fastest setting (it was found that
higher compression took 5x as long with a negligible decrease in size). This
helps keep disk cache sizes low.
While there are clear efficiencies in storing the frame out of the codec,
there's little benefit to storing it in a format higher than its native pixel
format since the pixel conversion is generally fairly quick. This commit will
index all frames in their native pixel format.
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.
This index system will have awareness of the disk cache state and be able to
fill in and store frames as necessary while keeping the disk cache under
user defined limits.
The encoder was moved to its own thread and will transcode the PCM from the
audio renderer into the chosen codec while the video frames are still
received. The implementation isn't perfect and could use some cleaning up, but
it is functional at the moment.
itsmattkc