Out in Front

Video-processor chip set fits picture to screen

You can quickly get into complex signal-processing territory when you have to adapt an image to different display geometries, such as from conventional 4-to-3 aspect ratio to 16-to-9 wide-screen format, and also support NTSC, PAL, SECAM, and S-VHS analog standards. The VPC3201B video-processor IC from ITT Intermetall eases the challenge by performing aspect-ratio conversion and signal processing under software control. It includes analog input circuitry; two 8-bit, 20.25M-sample/sec A/D converters; sync circuitry; video adjustments; scaling circuitry; and decoders for the various video-encoding standards. The pin-compatible VPC3200A also integrates a two-line adaptive comb filter for luma/chroma (Y/C) separation.

The companion DDP3300A display and deflection processor provides digital back-end processing and D/A conversion for RGB output. Using this IC, you can adjust contrast, brightness, and saturation; dynamically control peaking, modifying filter characteristics when the video signal has small high-frequency components; perform gamma correction; and insert overlays and text on-screen. The processor provides controls for CRT cutoff, white-level drive, and beam-current limiting, and it supports CRTs with 90 and 1108 horizontal/vertical deflection.

Both CMOS ICs in the chip set come in 68-lead PLCC packages, requiring a single 5V supply and a 20.25-MHz crystal. The I2C bus controls the devices, which cost $25 per pair (OEM).—by Bill Schweber

ITT Intermetall, Freiberg, Germany, docservice@itt-sc.de, http://www.itt-sc.de.