Blender expects float buffers to be in scene linear space, which was
violated bu the 1012bit movie reading code. While such image buffers
can be displayed correctly, performing operations in various areas
of Blender might lead to unexpected results.
The non-linear colorspace for ImBuf is expected to be "internal-only"
to a specific area, like VSE.
This is only done for Image and MovieClip data-blocks, sequencer still
reads movie files in their original colorspace as it helps performance and
sequencer can not be referenced from places where linear colorspace
for float buffer is really important.
Pull Request: https://projects.blender.org/blender/blender/pulls/141603
93be12fde0