About This Guide

The Indigo2 IMPACT™ Compression motion JPEG option card from Silicon Graphics® provides two independent channels of full-resolution, full-motion, real-time video compression or decompression for the Indigo2 IMPACT family of desktop workstations.

Indigo2 IMPACT Compression fully utilizes all calls and controls in the Silicon Graphics Compression Library (CL), and works with other Silicon Graphics programming libraries as well, such as the Video Library (VL).

This guide explains features of the CL and VL for IMPACT Compression and gives step-by-step instructions for creating programs using CL, VL, or both that make use of Indigo2 IMPACT Compression board capabilities.


This guide is written for the sophisticated user with a background in
C programming who wishes to develop programs for Indigo2 IMPACT Compression capabilities, with or without interaction with its on-board video capability or the Indigo2 IMPACT Video option.

Structure of This Document

This guide contains the following chapters and appendix:

An index completes this guide.


These type conventions and symbols are used in this guide:

Helvetica Bold  

Hardware labels


Executable names, filenames, IRIX commands, manual or book titles, new terms, program variables, tools, utilities, variable command line arguments, variable coordinates, and variables to be supplied by the user in examples, code, and syntax statements


Function name

Fixed-width type 

Error messages, prompts, and on-screen text

Bold fixed-width type  

User input, including keyboard keys (printing and nonprinting); literals supplied by the user in examples, code, and syntax statements (see also <>)


(Double quotation marks) On-screen menu items and references in text to document section titles


(Brackets) Surrounding optional syntax statement arguments


(Angle brackets) Surrounding nonprinting keyboard keys, for example, <Esc>, <Ctrl-D>