Method and apparatus for signal encoding producing encoded signals of high fidelity at minimal sizes

摘要

Methods and apparatus for determining encoding parameters of an encoder or a transcoder which yield an encoded signal of optimal measurable properties are disclosed. For a video signal, the encoding parameters may include quantization granularity, a measure of display resolution, and a frame rate. The measurable properties of an encoded signal may include a fidelity index, a relative size, and a relative flow rate. Reference data records quantifying properties of sample signals encoded according to experimental sets of encoding parameters are used to define parameters of conjectured analytical functions characterizing the encoding or transcoding functions. The analytical functions are then used to generate granular tables of estimated measures of encoded-signal properties. A fast search mechanism relies on the granular tables, together with sorted arrangements of the granular tables, to determine, in real-time, preferred encoding parameters for multimedia data streams received at an encoder or a transcoder.

主权项

1. A method, implemented in an encoder having a processor, comprising:
acquiring a video signal; determining descriptors of said video signal; acquiring characteristics of a receiver; selecting a preferred set of encoding parameters compatible with said descriptors and said characteristics for encoding said video signal to produce an encoded signal of a requisite fidelity index, said set of encoding parameters comprising a quantization step, a display resolution, and a frame rate; encoding said video signal according to said set of encoding parameters; formulating:
a first analytical function quantifying dependence of a fidelity index of said encoded signal on said quantization step, said display resolution, and said frame rate; anda second analytical function quantifying dependence of a relative size of said encoded signal on said quantization step, said display resolution, and said frame rate; acquiring a first number of reference data records, each reference data record indicating a fidelity index and a relative signal size corresponding to a respective set of encoding parameters; and executing a regression-analysis process to define said first analytical function and said second analytical function.