Patent ID: 7379496

Claim:
A method for decoding a bitstream for a sequence of video frames, the method comprising: receiving and processing first information for the sequence, wherein the first information indicates whether multiple spatial resolution coding is enabled for the sequence; determining the first information indicates that multiple spatial resolution coding is enabled for the sequence, and then for each of plural frames in the sequence, receiving and processing second information at frame level in the bitstream, the second information indicating one or more spatial resolution scaling factors for the frame; and outputting a result of the processing; wherein the plural frames comprise at least one I-frame and at least one P-frame, wherein each of the at least one P-frame has a reference I-frame among the at least one I-frame, and wherein for each of the at least one P-frame the one or more spatial resolution scaling factors are constrained to be identical to the one or more spatial resolution scaling factors for the reference I-frame for that P-frame.