METHOD AND DEVICE FOR COMPRESSING DATA TO BE TRANSMITTED AT CONSTANT BIT RATE

摘要

The invention concerns a method for compressing and transmitting digital data at constant bit rate comprising the following steps: separating input data into data blocks; transforming (12) each block by an orthogonal transformation; quantizing (14) the coefficients derived from the transformation; entropically coding (20) the quantized coefficients; temporarily saving the coded data in a buffer memory (18); evacuating a specific number of bits from the memory for each block; and adjusting, through feedback control (50) on the basis of a rate measurement produced by the coding, of the quantizing step to obtain, after coding, a number of bits close to the number of bits evacuated by the memory for each block. The feedback control (54) takes into account the bit rate of measured bits for at least the preceding block.