Multimedia Corner

Speed with Less Space

Although multimedia users are increasing their memory, hard disk storage, and CD-ROM speed, there is one multimedia commodity that is fixed for the immediate future. That commodity is the amount of storage space on a CD-ROM. When you start to add video to a multimedia product, storage needs mount up fast. A single thirty second clip can take nearly 40 Mb of space on your CD- ROM in some formats.

Horizons Technology, Inc., has a product called TrueMotion-s Compressor that provides on-the-fly compression and de-compression of video image frames. Using the product, the video inputs can be accepted from a video source, tuned to get the best output, then stored in a compressed format. Unlike general file compression products that simply decrease a file's size, this software- only solution compresses and decompresses single frames as needed to display the picture to the users requests.

The compression technique is interframe, rather than intraframe, and the result is 2X to 4X improvement in speed with similar reductions in the amount of CD-ROM space required. The package includes a demo of the product in action, some raw video clips to use in testing the package, the software to compress the video images, and the software to decompress the final output. The initial package includes a license for 500 CD-ROM containing the decompressor.

The package is easy to use with sliders, buttons, check boxes, and decision bars you can operate with the mouse. You can control the amount of grain, grain threshold, contrast, brightness, color saturation, color resolution, as well as focus on detail and compression level. The package allows you to test a variety of configurations, and display the resulting clips as you go.

The Macintosh version of TrueMotion-s Compressor requires a Quadra 800 or higher Macintosh, System 7.1, 16 Mb of RAM, a suitable A/V input card, a display system consistent with the A/V input, and a RAID or AV hard drive capable of 4 Mb/sec sustained transfer rate. A PowerMac and the Radius VideoVision Studio 2.0 card improve the performance significantly. A system with 32 Mb of RAM improves the operation with any of the suggested configurations.

The PC version of TrueMotion-s Compressor requires an 80486 33 MHZ or faster CPU, 16 Mb of RAM, and a 16-bit capable display adapter (DCI recommended). Also needed is a A/V-capable 540 Mb or larger hard disk, and a Video capture card capable of YUV-12 or M-JPEG output to the hard disk. The system will run on Windows 3.1 or later. The recommended system would be much larger and faster. A 75 MHZ PCI bus Pentium based computer with 32 Mb of RAM, 1 gigabyte of fast hard disk space, a PCI video capture board, and Windows 95 are recommended.

The package includes a group of video clips you can use to practice the compression-decompression algorithm. These include a Baja California road race, a railroad yard scene, river rafting sequence, clips of the San Diego Chargers vs the Pittsburgh Steelers AFL championship, an animated fighter plane cut, a slow motion horse race sequence, and simulated training talking head clips. The clips are specifically designed to show you how lateral, up- and-down, and animated sources respond to the algorithm. The source material has been chosen from Betacam-SP, S-VHS, and 24-fps film.

To use the product in a cross platform environment, you must purchase both the Windows and Macintosh versions. Although the compressed video can be run on both platforms, the decompressor software is sold only with the compressor software for each platform. The videos work with Apple Multimedia and QuickTime software on the Macintosh and Windows PC as well as the Video for Windows system for the Windows PC. The Windows version works in Windows 95, but not with 32-bit support.

Contributed by C. W. Mann, who also writes the syndicated computer column, BuzzBytes. Please direct your personal computer questions to him at cybercast@bigfoot.com.

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