Glitch-Free 2x1 SDI Video Switching Application Example

Description

In this application example there two asynchronous video sources from which the operator wishes to capture either input on a video recording device. (Alternately it could also be outputted to a display monitor.)

For this example, the system is controlled using serial RS-232 commands generated by a user application program running on a local laptop. 

Microtronix Application Solution 

The Microtronix DX-2200-SW-24, Dual-view 2x1 SDI Video Switcher product operates as a 2x1 frame-synchronous video switcher which ensures glitch-free video transitions of two asynchronous video source using proprietary IP that switches between video sources only at the start of video frames. 

The glitch-free functionally is enabled by Microtronix hardware logic which continuously buffers one frame of each video source.  The output video stream is re-constructed from either buffered video frame by reading the video data from the memory buffer synchronous to the start of frame marker used for output video stream.  Upon receipt of a switch command, upon the next start of frame marker, the frame buffer of the alternate video source is selected which maintains a glitch free transition to new video source.  It is also noted that as the two video sources are non-synchronous, drift may occur over time.  Therefore, a video frame may be added (repeated) or dropped to ensure alignment of the output frames. 

Switching is typically controlled via the Serial Control Port however, the user may optionally switch the video sources manually using the toggle switch on the DX-2200 unit is pre-programmed for this functionality. 

NOTE:
In this 2x1 Switcher mode of operation, the ancillary data and audio are not supported on either video inputs. 

View the DX-2200 Dual-view 2x1 SDI Frame-synchronous Video Switcher.