Proxies are expected to be fast to read. Storing them in cache has
little to no effect on performance.
This change also allows to omit invalidation of cache when user switch
between proxies and original media.
Reviewed By: sergey
Differential Revision: https://developer.blender.org/D9473
Variables renaned:
- cfra -> timeline_frame
- nr -> frame index
- cfra_over -> overlap_frame
Function seq_give_stripelem_index was renamed to seq_give_frame_index.
Replace BKE_sequencer wirh SEQ_render or SEQ_proxy prefixes.
In cases where function is very generic, only SEQ prefix is used.
Reviewed By: sergey
Differential Revision: https://developer.blender.org/D9439
Move functions closely related to rendering images and proxies into
render.c and proxy.c files. render.h and proxy.h are created for
functions used internally.
There should be no functional changes.
