Video decoder with constrained dynamic range

摘要

A technique for decoding video including receiving quantized coefficient level values representative of a block of video representative of a plurality of pixels and a quantization parameter related to the block of video. The technique includes de-quantizing the quantized coefficient level values based upon the quantized coefficient level values and the quantization parameter only if the quantized coefficient level values and the quantization parameter are jointly within a predefined range of acceptable values. The technique also includes inverse transforming the dequantized coefficients to determine a decoded residue.

主权项

1. A decoder that decodes video comprising:
(a) said decoder receives a bitstream containing quantized coefficient level values representative of a block of video representative of a plurality of pixels and a quantization parameter related to said block of video; (b) a de-quantizer of said decoder de-quantizing said quantized coefficient level values based upon said quantized coefficient level values, a transform block size and said quantization parameter when said quantized coefficient level values, said transform block size, and said quantization parameters are jointly within a predefined range of acceptable values to limit a dynamic range of said de-quantizing; (c) said decoder inverse transforming said dequantized coefficients to determine a decoded residue; (d) where the bitstream provided to said decoder includes a selective one of a plurality of available restrictions on the largest permitted level allowed in the bitstream and the selective one is received from the bitstream and depends on quantization parameter, transform block size, or source bit-depth.