The UMSCameraControl object is an Ultimedia Services Version 2 feature and does not apply to Ultimedia Services Version 1.2.1.
The UMSCameraControl object defines a generic interface to control a video camera. This class is a base class and is not meant to be instantiated. UMS supplies specific camera objects that inherits from this class to support a CCD camera on two video devices.
To learn more about the UMSCameraControl object, see:
For introductory information, see Video, Monitor, and Camera Control Support Objects.
enum ReturnCode {
Success,
Failure,
NotSupported,
InvalidArgument,
NotOpen
};
enum FadeValue {
FadeIn,
FadeOut
};
This method opens the camera device if necessary. Some devices require an open and some have other means of camera access (like use of an Atom in the XServer).
| in string path | Path to the camera device. This most likely is supplied by the Metaclass using the config file. |
This method closes the camera device if a close is required. It is assumed that the file descriptor is stored within the object as an instance variable.
This method sets the level of zoom. The zoom scale is defined to be integer values between 1 and 100, with 1 being Wide Angle and 100 being TelePhoto.
| in long scale | Integer zoom value. |
This method returns the current zoom level.
| out long scale | Integer zoom value. |
This method sets the camera pan. Pan values change according to the current zoom level. Pan is defined as the horizontal movement of the camera.
| in long scale | Integer pan value. |
This method returns the current pan value.
| Out long scale | Integer Pan value. |
This method sets the tilt value of the camera. The valid values of tilt change according to what the current zoom level is. Tilt is defined as the vertical movement of the camera.
| in long scale | Integer tilt value. |
This method returns the current camera tilt value.
| out long scale | integer tilt value. |
This method sets the fade value for the camera. Fade is defined as going from black to light and from light to black. The base class defines this as a scale because there could be cameras with a fine fade control. Usually though, there only is a fade in and fade out control. Because of this, there is an enumerated type defined for fade, which can be supplied to this method.
| in long scale | Integer fade value. |
This method returns the current fade value.
| out long scale | Integer fade value. |
This method adjusts the camera focus is supported.
| in long scale | Integer focus value |
This method returns the current focus value.
| out long scale | Integer focus value |
This method sets the exposure value for the camera. Exposure is defined as how much light the camera lets in. Like the rest of CameraControl methods, this value is an integer scale value that would be interpreted differently depending on the camera type. In other words, this method does not accept an f stop value. Since most cameras do this automatically, the default behavior of this object is to do an automatic exposure. The first time this method is called with any value, the exposure is set to manual until a reset (close/open).
| in long scale | Integer focus value |
This method returns the current exposure value.
| out long scale | Integer exposure value |
These methods adjusts the white balance with respect to the red/blue values. Since most cameras do this automatically, the default behavior of the camera is to do automatic white balancing. The first time either of these methods are called, the white balance is set to manual.
| out long scale | Integer exposure value. |
These methods returns the current white balance values.
| out long scale | Integer white balance values |
For introductory information, see Video, Monitor, and Camera Control Support Objects.