DIGITAL TELEVISION AT REDUCED BIT RATES

Various studies carried out on PAL and NTSC signals can be used to provide conservative estimates of the minimum bit rates required to digitally encode NTSC signals at various quality levels. These projections indicate that broadcast-quality signals can be obtained at bit rates of 43 Mbits/s using differential pulse-code-modulation (DPCM) encoding techniques. More sophisticated techniques such as component and interframe encoding may yield acceptable quality signals at substantially lower bit rates.