Video processor embraces high-speed A/V link
By Brian Dipert -- EDN, January 20, 2005
At last year’s Consumer Electronics Show, Silicon Image rolled out a three-chip transmitter-and-receiver family supporting the HDMI (high-definition-multimedia-interface) audio-plus-video interface it pioneered. This year, the company takes HDMI in an even more integrated direction, embedding an HDMI receiver within its $13.95 (10,000) SiI 8100 video processor (see “Digital-multimedia interface grows up,” EDN, Jan 22, 2004, pg 22). Targeting direct-view digital TVs, such as LCD and CRT-based units, the SiI 8100 also supports high-definition RGB and component-video inputs to bridge the analog-to-digital transition, along with a standard-definition ITU-R BT.656 video-input port. Output options include a 10-bit triple DAC (with 8- to 10-bit gamma expansion as necessary) for RGB and component video, an 18- or 24-bit TTL (RGB) driver, and a dual-channel LVDS transmitter.
Silicon Image calls the SiI 8100 a processor, though, not just a signal shuttler. What goes on between the chip inputs and outputs? The device can bicubically scale incoming images to television resolutions of as many as 1920×1080 pixels (interlaced) and to PC-graphics resolutions reaching SXGA (1280×1024 pixels at 75 Hz). It can also adaptively stretch 4-to-3 aspect-ratio inputs to a 16-to-9 ratio and eliminate moiré. It can convert 50-Hz video to 60 frames/sec, tackles interlaced-to-progressive-scan conversion (including inverse 2-to-2 and 3-to-2 pulldown), and creates picture-in-picture displays. Other video-processing capabilities include white- and black-level expansion; dark- and gray-area UV suppression; hue, saturation, brightness, and contrast controls; RGB-to-component-video and component-video-to-RGB color-space conversion; and PC-compliant RGB-color adjustments.
What about the audio coming in over HDMI? The Sil 8100 extracts it, which is not a trivial function; don’t forget that as part of this task, the SiI 8100 implements HDMI’s HDCP (High-bandwidth Digital Content Protection) scheme for both audio and video. The Sil 8100 then passes it on, over both S/PDIF and I2S outputs, to other system circuitry for processing and playback. Silicon Image has schedule availability of sample units, which will come in a 256-pin LQFP, for April, with volume production following in June.
Silicon Image, 1-408-616-4000, www.siliconimage.com.
