Vorrichtung zur Kodierung eines Videosignals

摘要

A device comprising an MPEG encoder (2) is provided with a preanalyser (8) which encodes each picture with a fixed step size (Q2). The preanalyser is coupled to a computing circuit (9) which computes, for each type of (I, P, B) picture, a target value (T) for the number of bits for encoding said picture, as well as a suitable distribution of the target value among the macroblocks of the picture. A proportionally integrating control circuit (7) controls the quantization step size (Q1). Since the PI control circuit does not introduce any residual errors, the desired number of bits per picture or per group of pictures is achieved within narrow limits. The output signal is eminently suitable for recording and subsequent editing. <IMAGE>