METHOD AND APPARATUS FOR ENCODING VIDEO SIGNAL AND METHOD AND APPARATUS FOR DECODING VIDEO SIGNAL

摘要

Provided are a method and apparatus for encoding a video signal and a method and apparatus for decoding a video signal. The method of encoding the video signal includes: determining an optimum scaling bit depth of the video signal in consideration of a maximum bit number of an intermediate value obtained during transformation of the video signal and a maximum bit precision of the video signal; scaling the video signal according to a local shift value corresponding to a difference between the determined optimum scaling bit depth and an original bit depth of the video signal; and transforming the scaled video signal.

主权项

1. A method for decoding a video, the method comprising:
obtaining transformed coefficients of a current block from a bitstream; generate scaled transform coefficients of the transform block by performing inverse-quantization and scaling on the quantized transform coefficients; generating intermediate sample values by performing vertical inverse-transformation on the scaled transform coefficients; generating residual values of the transform block by performing horizontal inverse-transformation on the intermediate sample values; generating a prediction block by performing intra prediction or inter prediction; and, restoring sample values using the residual values of the transform block and the prediction block, wherein the scaling on the quantized transform coefficients comprises: determining an offset value based on a scaling variable, adding the inverse-quantized transform coefficients to the offset value and bit shifting on the added transform coefficients by the scaling variable, wherein the scaling variable is generated by using a size of the transform block and the bit depth of samples, and wherein the vertical inverse-transformation is performed by multiplying a transform matrix by the scaled transform coefficients.