As far as I know, in the compositor, yellow sockets are for images, gray sockets are for values, purple sockets are for vectors. From this, however, I cannot know the ranges of these values. In particular, I am trying to have an image showing the "Vector" pass of the Cycles engine. The "Vector" socket (purple) should be normalized, but in which range? I am trying with different numbers and it seems that it is from -127 to 128, but I am not sure. I am splitting the components, dividing by 128, adding 1 and then multiplying by 0.5 and clamping (clamp means between 0 and 1?).
The first question is: what is the range of the velocity pass? It seems to be the number of delta pixels, so the maximum is the resolution of the image, is this correct?
The second question is: what range the compositor (and the viewer) expects? it seems to me that it expects RGBA values between 0 and 1, and then it multiplies by 255 if the color depth is 8, and by 2^16 if the color depth is 16: is this correct?