Alpha-blended Overlay of Computer-Generated Graphics

Description

For this application example, the objective is to alpha-blend an active computer generated graphic onto an SDI video stream. The system is controlled from a local laptop (not shown) running a user application program.

Microtronix Application Solution 

This application example in implemented using the Microtronix DX-4400-TI-2K, 3G-SDI Dual-channel Text and Graphics Overlay Inserter product. 

For this system, the primary video source is connected to SDI Input 1 and the computer generated video overlay layer is connected to SDI Input 2. The overlay is generated on a black background and the DX-4400 is configured to display the overlay layer on top of the primary video stream with the black background treated as transparent. The DX-4400 unit is controlled via either the Serial Control port or a UDP TCP/IP connection from a local laptop (not shown). 

Having a video delay from input-to-output of approximately one video frame, the system is designed for live studio recording and broadcast applications.   

NOTE: 

For this application, the computer generated overly is typically an active user graphic. However, it is also possible on the DX-4400 product to use the on-board ARM processor to generate active graphics (widgets) to display active gauges or graticule overlays using the QML Qt scripting language of the DX-4400 product. 

Both the DX-2200-TI-24 and the DX-4400-TI-2K products support this type of functionality.