Zoom Communications, Inc.

Shiyan Zhang

Jing Wu

Rui Li

Yi Guo

Zhichu He

Yichen Zhang

Minxia Yang

Bo Ling

Methods, systems, and apparatus, including computer programs encoded on computer storage media for fast search of transform kernel selection. A set of transform kernels are selected. Multiple images are encoded via the AV1 coded using the selected transform kernels. The encoded images are transmitted to another computing device.

Fast search and selection of a transform kernel for AV1 encoding

Fast parameter search for chroma from luma (CFL) intra prediction in video encoding is provided. A video encoder determines a value of a parameter of a linear CFL predictor for a coding block of a frame of a video. The determining includes dividing a search range within a value range of the parameter into three portions by a starting value: the starting value and values on two sides of the starting value. The encoder determines cost values of parameter values from the three portions and select the value of the parameter that corresponds to the lowest cost value. The encoder further encodes the coding block of the frame into a bitstream representing the video using the CFL predictor with the selected value of the parameter.

Fast parameter search for chroma from luma intra prediction in video coding

Deriving in-loop filter parameters via training for video encoding is provided. A video encoder performs inter prediction for a frame in a set of frames of the video to generate prediction residuals for the frame. The inter prediction for the frame is performed based on a reconstructed frame in the set of frames filtered using an in-loop filter. The value of a parameter of the in-loop filter is determined by determining, for each candidate in-loop filter parameter value, a visual quality metric for a set of training frames in training video sequences filtered by the in-loop filter. The candidate in-loop filter parameter value that corresponds the highest visual quality metric can be selected as the value of the parameter of the in-loop filter. The video encoder further encodes the prediction residues of the frame and the parameter of the in-loop filter into a bitstream representing the video.

Deriving in-loop filter parameters for video coding

Growing community of inventors

Hangzhou, China

Shiyan Zhang