Feature request: Mixer Keyer behaviour

[jesperstarkar]

From AMCP 2.1 wiki:

Replaces layer n+1's alpha with the R (red) channel of layer n, and hides the RGB channels of layer n

Why was it decided to use the R channel as the source for the keyer? If an alpha channel is available why can't this be the source?

Suggestion: Add an additional parameter mode to the AMCP protocol, indicating which channel(s) to use as key source.

Default value: A (breaking change) or Default value R (current implementation)

Possible values:

"R",        /// red channel
"G",       /// green channel
"B,         /// blue channel
"A,         /// alpha channel
"RGB"   /// rgb channels combined

[mint-dewit]

Every channel is defined by an integer between 0 and 255. In a file with an alpha channel this means four channels: red, green, blue and alpha.

If the file does not support alpha channel it is only mising one channel, thus you add an alpha or keying file, but you only need one of the channels. Inside a key signal all the channels have the same values (that's why it is in black and white) thus it doesn't matter what channel you use.

This issue should probably be closed.