"if the pixel in the key source lies within the range, then it is replaced by the corresponding pixel in the other stream"
"Inlet 1: direction 0|1 : which stream is the key-source (0=left stream;
1 = right stream)"
So -- "direction 0" should mean that matching colors in the left image would be replaced by pixels from the right image (because 0 means that the left stream is the key source and, per above, pixels from the key source within range are replaced).
So I've got an image of a bad CGI dinosaur with a solid green background = 0.129 0.945 0 (RGB) -- putting this into the left inlet of chromakey. This is the one whose pixels should be replaced, so... direction 0, right?
But when I set "value 0.129 0.875 0" and "range 0.15 0.15 0.15" to match the green background, then I get the background coming through solid, and a transparent hole in the middle where the dinosaur is.
If I set "direction 1" then I get the foreground dinosaur, and the green gets replaced.
So it seems that the "direction" message is explained backward? Or is that part correct, and the explanation of "key source" is wrong?
Or perhaps there is some other way to interpret those statements...?