What are Constrained Parameters Bitstreams (CPB) for video?
A. MPEG-1 CPB are a limited set of sampling and bitrate parameters designed to normalize decoder computational complexity, buffer size, and memory bandwidth while still addressing the widest possible range of applications. The parameter limits were intentionally designed so that a decoder implementation would need only 4 Megabits of DRAM. Parameter Limit ————– ————————— pixels/line 704 lines/picture 480 or 576 pixels*lines 352*240 or 352*288 picture rate 30 Hz bit rate 1.862million bits/sec buffer size 40 Kilobytes (327,680 bits) The sampling limits of CPB are bounded at the ever popular SIF rate: 396 macroblocks (101,376 pixels) per picture if the picture rate is less than or equal to 25 Hz, and 330 macroblocks (84,480 pixels) per picture if the picture rate is 30 Hz. The MPEG nomenclature loosely defines a “pixel” or “pel” as a unit vector containing a complete luminance sample and one fractional (0.25 in 4:2:0 format) sample from each of the two chrominanc
