Patent ID: 9131210
Filing Date: 2015-09-08
Classification: H04N

Abstract:
1. A method for decoding an encoded video bit stream, the method comprising: entropy decoding a block of transform coefficients from the video bit stream; applying a first one-dimensional (1D) inverse transform of a two-dimensional (2D) separable inverse transform to the block of transform coefficients; reducing a bit width of each intermediate result of applying the first 1D inverse transform, wherein the reduced bit width of a first intermediate result and the reduced bit width of a second intermediate result are different, wherein reducing the bit width comprises scaling the bit width of each intermediate result based on a predetermined shift amount; and clipping the scaled bit width of each intermediate result to a predetermined bit width to attain a final bit width, wherein the final bit width for a first scaled intermediate result is different from the final bit width for a second scaled intermediate result; storing the reduced bit width intermediate results in a transpose buffer; and applying a second 1D inverse transform of the 2D separable inverse transform to the reduced bit width intermediate results to recover a block of residual values.