Extron electronic 12800 manual Explaining Virtual I/O Switching

Virtualization/Control Software

Explaining Virtual I/O Switching

A Matrix 12800 system consists of from one to nine BMEs, each of which can have as many as 128 inputs and 128 outputs. It is usually desirable to have certain inputs switch together as a set, to follow each other. For example, if the system consists of a 128 x 128 video BME and a 128 x 128 audio BME, you want your video images on your video monitors to match the audio from the sound system (for example, video and audio from a DVD). You would want the video and audio to follow each other when they are switched to another display. This type of switching requires the two BMEs to communicate with each other so that they both switch to the correct inputs simultaneously. In the traditional and simplest configuration, hardware is usually designed to switch both BMEs to the same input.

S-video presents an example in which follow is always required. The luminance

(Y)and chrominance (C) signals must be switched as a pair of signals. Traditional hardware does this by causing the paired signals to follow each other, either in a single box made only for S-video or by using two composite video switchers and forcing them to follow each other.

A better solution would be to have a single video matrix switcher box that can be field-programmed to be either an S-video switcher, a composite video switcher, or some combination of both. That is what the Extron Virtualization/Control software does; it groups physical input connectors and physical output connectors together into virtual inputs and virtual outputs, each of which switches from one (composite video) to seven (RGBHV and stereo audio) virtual planes. The software then downloads the virtual map to the system memory of the Matrix 12800.

Assume a Matrix 12800 video switcher and a Matrix 12800 audio switcher; to support the S-video example above, the Virtualization/Control software can map (logically split) the video switcher into a Y plane and a C plane, and the audio switcher into two (left and right channels) audio planes. This creates a system with up to 64 virtual inputs and 64 virtual outputs in 4 virtual planes (Y, C, and left and right channel audio). (The limit of 64 inputs and outputs comes from splitting the 128 x 128 video BME into 2 halves.) In this example, half of the audio BME

is not included in the virtual map since only 64 of the 128 ports are used, so the configuration would be more cost-effective with a 64 x 64 audio BME.

As an alternative, using the same Matrix 12800 video and audio switchers, the software can map the system into a composite video matrix consisting of up to 128 virtual inputs by 128 virtual outputs in 3 virtual planes (video and audio).

The software can also map the same two switchers into a component video system consisting of up to 42 virtual inputs by 42 virtual outputs in 5 virtual planes (Y, R-Y, B-Y, and left and right audio). In this configuration two physical input BNCs and two physical output BNCs are not used. As in the S-video example, the audio plane would be served more cost-effectively using a 64 x 64 audio BME.

Lastly, the software can map the same two switchers into a 25-input-by-25- output component video system, a 20-input-by-20-output S-video system, and a

13-composite-input-by-13-composite-output system, each with audio (58 virtual inputs by 58 virtual outputs). In fact, the video switcher can be subdivided to accommodate any combination of video formats so long as the total number of virtual inputs and virtual outputs does not exceed the number of physical inputs and outputs (up to 128 x 128).

The number of physical input connectors required can be calculated with the equation Vi * Vp = Pi, where Vi is the number of virtual inputs, Vp is the number of virtual planes, and Pi is the number of physical inputs required. The equation for output connectors is Vo * Vp = Po.

3-2 Matrix 12800 Switchers • Virtualization/Control Software