This reference design is used as a starting point for a final video datapath design. System design tools such as SOPC Builderallows an automated way of generating control and arbitration logic in a time-efficient manner. This enables designers to use a video design framework that promotes the fastest design cycle for video applications.
The blocks include scalar, deinterlacer, frame buffer, color plane sequencer, clipper, color space converter, gamma corrector, chroma resampler, alpha blending mixer, 2D FIR filter, 2D Median filter, line buffer compiler, and even a test pattern generator for debug purposes.Ī reference design framework tool is also part of the video library. Altera’s Video and Image Processing (VIP) Suite are examples of a ready-to-use broadcast resolution video building blocks. The most common video building blocks are already available and can be easily incorporated into a new design. Video Processor Building Blocks and Design Tools The video resolution can go up to a maximum of 1920x1200p60 depending on the application. The data rate for each interface is listed in Table 1. High definition multimedia interface (HDMI) and DVI are also used for local display monitors. SDI is the industry standard for broadcasting uncompressed video delivery within the studio. Each output stream represents an edited program for live broadcast or storing for later retrieval.įigure 1. A typical switcher can support multiple SDI ports.
FPGAs are ideal for this type of video system design with their internal parallel digital signal processing (DSP) blocks, an abundance of embedded memory blocks, a large number of registers, integrated transceivers that can handle 1080p 3G-SDI, and high-speed memory interfaces. The video processing blocks are the essential building blocks of the video switcher. Before the edited streams are routed out for transmission, they are also routed to a local multi-viewer display for content monitoring. The format converter provides up and down conversion between HD (1080i/p and 720p) and SD (480i and 576i). The uncompressed SDI video streams are routed into a video special effect block that adds local text information, up/down cross resolution conversion, or video overlay. Figure 1 shows a broadcast video switcher, the gateway of the transmission studio, that processes streams of uncompressed video from standard definition (SD) to HD, including 1080p. Designers can select either a low-cost or a high-end FPGA to fulfill the system requirements. The FPGA Alternative for the Studio Switcher ExampleįPGA SOCs provide an alternative to the traditional ASIC or ASSP for video processing. Many standard consumer types of ASSPs are available to address this issue, but for higher end broadcast quality video monitors, more video processing power and flexibility is needed to enhance the performance of the video output quality. This virtually removes motion blur on high end 60/120 Hz/1080p LCD monitors. One method is to remove any annoying film judder by up converting 1080p at 60/120 Hz using motion-compensating deinterlacing by inserting additional interpolated pictures into the original picture sequence. This is because the 24 frames are repeated two or three times (2:2 or 3:2 pull-down) to match the LCD panel’s refresh rate. The conversion of 24p film sources to the LCD refresh rate of 50 Hz or 60 Hz causes film judder. Existing LCD monitors use motion-adaptive deinterlacing techniques to create the progressive frame. LCD weaknesses like motion blur and film judder affect the video monitoring experience drastically. For high end color graphics, CRTs offer some advantages because LCDs can only display the colors available in the pixels, and so they have less color depth than CRTs.
Video displays have evolved from bulky CRTs to the popular LCDs for today’s professional video monitor. Video processing with FPGAs still holds a key advantage over other types of technologies due to the inherent flexibility and scalability of these devices. Today’s broadcast equipment must be capable of handling all types of video formats and resolutions. The majority of broadcast content is already streaming in high definition (HD) and is moving from an interlace format to a progressive format. Video standards and methods of encoding/decoding have made tremendous progress over the last decade with the availability of large system-on-a-chip (SOC) solutions using ASSPs, ASICs, or FPGAs.