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Sony Camera Controller class

camcontrol-0.01.tgz (10kB)

This software provides a single class that allows the Sony camera to be controlled, along with an example program that uses it. Currently only commands to move, zoom and control power are implemented. It has been tested on Intel based PC's running Linux and FreeBSD. It has also been tested on an Indy running Irix and a Sun sparc 4 running solaris.

In theory, the software should beable to operate with more than one camera on the VISCA bus, but this has never been tested, hence there are no supporting methods for camera selection.

A number of viewing parameters can be remotely controlled, including the yaw and pitch angles (x and y), and the zoom factor (z). The controlling integer values x, y and z can take the following values.

-860 <= int x <= 861    -> absolute yaw angle of camera
                           (roughly -95 degrees -> +95 degrees) 
-282 <= int y <= 283    -> absolute pitch angle of camera
                           (roughly -20 degrees -> +20 degrees) 
   0 <= int z <=1023    -> absolute zoom of camera

It is fairly clear that x and y control linear stepper motors — so the relationships between x and yaw and between y and pitch are linear. However, the relationship between z and the zoom factor is not clear, and in fact is not even described in the documentation. However, a relationship has been derived experimentally, as follows.

We have found a formula to link n, the number of ceiling tiles visible in an image, to z. However, n is a relative number and hardly a useful measure of the absolute zoom factor. To find a measure of the magnification factor, first z is altered until the size of the image in a VR headset is the same as reality. Here z is found to be around 362. The magnification factor is thus found to be:

M(z) = f^-1(362) / f ^-1 (z)