Patent ID: 11877000
Assignee: DOLBY LABORATORIES LICENSING CORPORATION
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method to decode a coded bitstream with scalable canvas size, the method performed by a processor and comprising, for a current picture:
receiving a current picture width and a current picture height comprising unsigned integer values;
receiving first offset parameters determining a rectangular area on the current picture, wherein the first offset parameters comprise signed integer values;
computing a current area width and a current area height for the rectangular area on the current picture based on the current picture width, the current picture height and the first offset parameters;
for a reference area, accessing a reference area width, a reference area height, a reference area left offset, and a reference area top offset;
computing a horizontal scaling factor based on the current area width and the reference area width;
computing a vertical scaling factor based on the current area height and the reference area height;
computing a left-offset adjustment and a top-offset adjustment of the current area based on the first offset parameters; and
performing motion compensation based on the horizontal and vertical scaling factors, the left-offset adjustment, the top-offset adjustment, the reference area left offset, and the reference area top offset, wherein accessing the reference area width and the reference area height, further comprises, for a reference picture:
accessing a reference picture width and a reference picture height;
receiving second offset parameters determining a rectangular area in the reference picture, wherein the second offset parameters comprise signed integer values;
computing the reference area width and the reference area height for the rectangular area in the reference picture based on the reference picture width, the reference picture height and the second offset parameters; and
computing the reference area left offset and the reference area top offset based on the second offset parameters.