LEVEL DECISION IN RATE DISTORTION OPTIMIZED QUANTIZATION

摘要

A computing device, such as a video encoder, determines an initial quantized level for a coefficient of a coefficient block and determines whether the coefficient is less than the product of the initial quantized level and a quantization step size value. In response to determining that the coefficient is less than the product of the initial quantized level and the quantization step size value, the computing device determines rate-distortion costs of quantizing the coefficient to be the initial quantized level for the coefficient, the initial quantized level minus one, and in some circumstances, 0. The computing device determines an actual quantized level for the coefficient based at least in part on the calculated rate-distortion costs and includes the actual quantized level in a quantized version of the coefficient block.