FIG. 18 illustrates a generic video encoder 1800 (e.g. HEVC encoder) for some embodiments of the invention. The encoder 1800 receives a video stream from a video source 1805 and produces a compressed, encoded bitstream 1895 to be stored and/or transmitted.

The video encoder includes a transform module 1810, a quantization module 1815, an entropy encoder 1820, an inverse quantization module 1825, an inverse transform module 1830, a deblocking filter 1840, a sample adaptive offset (SAO) filter 1845, a frame buffer 1850, a rate control module 1835, and a prediction module 1890. The prediction module 1890 includes a motion estimation module 1860, a motion compensation module 1865, an intra-prediction module 1870, and a mode decision module 1880. The video encoder 1800 also includes a video display 1855 in some embodiments.

The quantization module 1815 is a module that uses quantization parameters to perform quantization on transform coefficients (e.g., DCT) from the transform module 1810. In some embodiments, the transform module 1810 can be completely bypassed (such as under the transform-bypass mode supported by HEVC) so that the quantization module 1815 receives image values or image prediction error values without transform. The quantization module 1815 applies different QP values for different regions/blocks for each color component. The QP values used by the quantization module 1815 are also coded as luma QP values and chroma QP offsets into the bitstream 1895. In some embodiments, the QP values being used by the quantization module 1815 are determined and supplied by the rate control module 1835.