| 摘要 |
The method includes throughput regulation by variation of quantisation pitch based on a regulation line, a logarithm of the throughput as a function of a regulation pitch linked to the quantisation pitch, the slope of which, substantially constant from one image to another of the same sequence, is adjusted during coding of the preceding image (50) as a function of the throughputs obtained during the pre-analysis (42) and the regulation (49) of this preceding image, and the ordinate of which at the origin is determined by the throughput obtained during the pre-analysis of the current image (47). This line makes it possible to calculate the regulation pitch for the current image corresponding to the desired throughput (48). Regulation per band (48), a succession of macroblocks on a line, is then carried out as a function of parameters such as the throughput of the preceding band in pre-analysis and regulation phase, change in the throughput from one band to another, prediction of the end-of-image throughput, in order to adjust the throughput of the current image. This method applies to recording on video tape and facilitates the operations of assembly image by image. <IMAGE> |
