Requirement

Professional HD video equipment manufacturer required a SD/HD-SDI Dual Input Switcher board to support picture-in-picture, picture-and-picture, graphics overlay and alpha blending of video streams. The design needed to support auto detection of video sources at 720p, 1080i, 1080p and industry standard frequencies (30/50/59.94/60 Hz). The operation of the board was to be dynamically controlled through a serial port or manually through switches.

Challenge

Develop a highly integrated low-cost dual port SDI switcher board capable of processing multiple HD video streams at up to 1080p30. In addition to the video processing logic, the design requires an embedded control processor to automatically detect incoming video and switch between the various modes of operation. During the switching of video sources, the output video must be glitch free and gen-lock synchronized to the master input.

Solution

Video processing at 1080p30 places high load on DDR2 memory bandwidth and requires the use of high speed IP core logic. The video processing algorithms used also consume both a large number of embedded RAM blocks and logic elements within the FPGA which necessitates the use of advanced high density FPGA devices.

Microtronix was able to meet customer objectives for performance, cost and power dissipation using a high-density Altera Cyclone III FPGA. A 64-bit DDR2 memory interface was used to buffer the video streams, synchronize the sources and ensure adequate memory bus bandwidth for the video processing.

The SDI interfaces utilize Gennum HD/SD SDI transmitter and receiver components which fully supports SMTPE video standards.

Result

Microtronix achieved the cost and performance objectives for the design of the embedded SD/HD-SDI 2x1 Switcher with support for dynamic video detection, PIP, PAP with alpha blended video overlay. The use of a high density Cyclone III FPGA provided the customer with the design flexibility to add additional features as may be required to address new market opportunities.

Related: SDI Video Overlay Products