Apparatus and method for encoding video using different second-stage transform

摘要

A system, apparatus, and method of encoding a video stream having a plurality of frames, each frame having a plurality of blocks is disclosed. The method includes selecting a group of blocks from a current frame of the plurality of frames, determining a plurality of first stage transform coefficient matrices for the group of blocks using a first transform technique, determining a DC second stage transform coefficient matrix for the group of blocks based on at least some of the plurality of first stage transform coefficient matrices and using a second transform technique on a processor, and encoding the group of blocks into an encoding format using the DC second stage coefficient matrix and the first stage coefficient matrices.

主权项

1. A method comprising:
identifying a current block of a current frame of an input video stream; generating an encoded block from the current block by encoding, by a processor in response to instructions stored on a non-transitory computer readable medium, the current block, wherein encoding the current block includes:
generating a first order transform block including a plurality of transform coefficients based on at least a portion of the current block using a first transform technique,identifying a plurality of average intensity coefficients from the plurality of transform coefficients, wherein each average intensity coefficient from the plurality of average intensity coefficients represents an average intensity of a respective subblock of the first order transform block,determining whether to encode the current block using a second transform technique, andgenerating a second order transform block based on the plurality of average intensity coefficients using the second transform technique; including the encoded block in an output bitstream; and storing or transmitting the output bitstream.