SYSTEM FOR RESHAPING AND CODING HIGH DYNAMIC RANGE AND WIDE COLOR GAMUT SEQUENCES

摘要

A video data encoder generates a first metadata structure to describe one or more transfer functions to be applied by a decoder to reshape decoded video data into video data. The encoder segments a transfer function relative to P pivot points. It then allocates P cells in the metadata structure for storing the P pivot points. Each transfer function segment is fitted to a respective equation having N coefficients based on the order of the equation. The encoder allocates N+1 cells for each pivot point except for the Pth pivot point and stores the number N in the first cell and the N coefficients in the remaining cells. The encoder generates a second metadata structure, associated with a video data set, that includes data identifying the transfer function to be applied to the video data set. The encoder encodes the video data including the first and second metadata structures.

主权项

1. A method comprising:
encoding video data, including: generating a first metadata structure to describe a transfer function to be applied to reshape decoded video data to generate output video data having at least one of a higher dynamic range or wider color gamut than the decoded video data, the first metadata structure being associated with a sequence of pictures, a group of pictures, or an image essence of the video data, the generating of the first metadata structure including:
dividing data representing the transfer function into a number of segments the segments being defined by pairs of successive pivot points of a number, P, pivot points including a first pivot point and a last pivot point, P being an integer;allocating a cell in the first metadata structure to store a value indicating the number of pivot points and storing the value P in the allocated cell;allocating P pivot point cells in the first metadata structure;storing data values representing the P pivot points into the P pivot point cells;fitting a respective equation to each segment, each equation having a number, N, coefficient values where N is an integer that varies based on characteristics of the segment; andfor each pivot point except the last pivot point:
allocating N+1 cells in the first metadata structure;storing the value N for the segment into a first one of the N+1 cells; andstoring the N coefficient values in the remaining N cells of the N+1 cells; generating a second metadata structure associated with a picture, slice, processing window or sub-picture element, including allocating a cell in the second metadata structure and storing, in the allocated cell of the second metadata structure data identifying the transfer function; and encoding the video data and including the first and second metadata structures with the encoded video data.