* Rename all Rgba instances to Rgb.
* Remove alpha value from the RGBA Matrices and apply the 4x4 matrix
only to the R, G, B channels.
* Restore the alpha from the input unchanged.
PiperOrigin-RevId: 467208888
(cherry picked from commit 8760ee48b910a4a34e6cc5008b660513203b05e8)
This allows the GlEffectsFrameProcessor to later handle HLG and PQ
differently, or limited and full color range differently.
No functional change intended in this CL.
PiperOrigin-RevId: 466070764
(cherry picked from commit 536d42c865fd692c1d1799082077906287a2c3f0)
* Add RgbaMatrix interface implementation.
* Add Builder class for easy adjustments.
* Adjust existing RgbaMatrixPixelTests to use new RgbAdjustment class.
PiperOrigin-RevId: 465545429
(cherry picked from commit a76dbfd363e2d167b13d2bcd978979bcfd69b071)