Selection of signal sources A, B, C ,D

The setting all the A, B ,C and D sources is identical for all cameramen V/C.
The fundamental part of studio configuration is a selection of a source. Usually, a studio project allows you to place there 4 input signals A, B ,C and D that are set on the mixer in an additionally opened panel.
In a studio design, the first two of them, namely A and B, are almost always images of presenters (Talents), from CAM 1 to CAM 4 sources. A keying filter is applied to these sources.
The applied key removes a uniform background (e.g. green), on which the presenter is filmed.
The third and fourth signal source – C and D may be a film or a still image. They are usually displayed on virtual screens that are a part of studio scenography. Everything depends on the project. In the picture below, you can see tree images of presenters (source A, B, C) and studio screens, where a film (source D) is displayed

Most often the default A, B , C and D sources were defined by a studio designer, but you go to the Studio Editor and create your own settings, e.g. remove a Talent or add a screen. In each studio, signals can be used in a different way. Due to this flexibility, the signals have been described in a studio configuration panel in a universal way – symbols A, B , C and D (image below)

There are four separate rows of buttons with identical descriptions for sources A, B ,C and D. This enables a separate regulation of parameters for sources A, B , C and D.
The input signal for studio composition can be: a transparency (Off), a camera image (CAM_1, 2,3,4), a video file (Media 1, 2), an image/bitmap (Still 1, 2),
And so are called the buttons located in four rows below the studio previews. The button with selected source is highlighted . Changing the input source takes place immediately, so you can change it during the live broadcast.
After selecting the appropriate signal sources, a figure of a presenter will be displayed against a studio scenography, and a selected video file or a still image will be shown on virtual screens. If a keying filter has not been enabled for the source with a presenter figure, you have to switch it on and set its parameters. After applying the correct keying parameters, a background against which the presenter is filmed (e.g. green) will be removed and the figure of the presenter will be visible against the background of the studio scenography.
In order to make the figure of the presenter fit better into set design you have used, you can adjust the figure’s size and position in the studio. A separate window is used for changing these parameters. The window can be opened with a button located next to the buttons used for the studio’s signal sources selection.
This window works on the same principle as the Placement window earlier described in the DSK section. The only exception is an additional function Aspect Ratio: Keep / Stretch described on the following pages of the manual.