Estimating the number of bits required to compress a plurality of samples using a given quantisation parameter by calculating logarithms of quantised samples

摘要

Samples of a portion of a signal are quantized using a trial quantization parameter. An estimate of the bit count is then produced by evaluating, for each sample, an expression involving a logarithm to base n of the value of the quantized sample, and summing the results over all samples. This is preferably achieved using the equation of claim 5 or the SIGNET equation of claim 7. The output bit count corresponds to an estimate of the output bit count for the portion of the signal once encoded using a code, such as a Huffman code. Preferably, the output bit count is compared to a target bit count criteria and if it does not meet the criteria the quantization parameter is adapted and the aforementioned steps are iteratively repeated.