Other

Apple Inc.

Felix Chou

Xiaohua Yang

Francesco Iacopino

Linfeng Guo

Xiang Fu

Ying Jian He

Krishna Rapaka

Mukta Gore

Techniques for encoding video with reduced frame-boundary artifacts are presented. The techniques include a video encoding method, where, when skip mode is selected as a motion prediction coding mode for a pixel block predicted from a reference block of a reference frame, estimating an amount of the reference block that extends beyond the edge of the reference frame. If the amount beyond the edge does not exceed a threshold, the prediction may be coded with skip mode. If the amount beyond the edge exceeds a threshold, the pixel block may be partitioned, and the partitioned blocks may be coded with motion prediction.

Frame boundary artifacts removal

Techniques are disclosed for developing quantization matrices for use in video coding. According to these techniques a first quantization matrix may be derived from a second quantization matrix by scaling quantization values of the second quantization matrix by scaling parameters. The scaling parameters may increase according to distance between each matrix position and a matrix origin, they may be derived from characteristics of a video sequence to be coded, or both. The first quantization matrix may be communicated to a decoder. Thereafter, a video sequence may be coded predictively. As part of the coding, pixel data of the video sequence may be transformed to a plurality of frequency domain coefficients, and the frequency domain coefficients may be quantized according to the first quantization matrix.

Techniques for calculation of quantization matrices in video coding

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Saratoga, CA, United States of America

Felix Chou