Software codec for personal computers based on the discrete cosine transform
Chris Pitts, J. M. Beaumont, Saul Cozens, Neil A. Emms, David Jaz Myers · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1994
This paper describes the development of a compatible encoder and decoder pair (codec) for motion video. A study has been undertaken of compression algorithms of low computational complexity, which may be candidates for running in real time on a personal computer (PC). From this study a DCT based algorithm was selected for further development and implementation on a PC. The code has been implemented in C, with critical routines optimized in assembly language. The encoder/decoder is intended to facilitate video communication applications between personal computers without the need for dedicated compression hardware. A 33 MHz client PC connecting to a remote 66 MHz server PC via a 64 kbit/s dial-up digital link has been demonstrated. Live images grabbed by the server PC are compressed and transmitted to the client PC, requiring about 40 of the available 64 kbit/s. For 64 greyscale image of 144 X 120 pixels a frame rate of about 10 frame/s is achieved.