Partial frame utilization in video codecs

Embodiments of the present invention provide techniques for efficiently coding/decoding video data during circumstances where a decoder only requires or utilizes a portion of coded frames. A coder may exchange signaling with a decoder to identify unused areas of frames and prediction modes for the unused areas. An input frame may be parsed into a used area and an unused area based on the exchanged signaling. If motion vectors of the input frame are not limited to the used areas of the reference frames, the unused area of the input frame may be coded using low complexity. If the motion vectors of the input frame are limited to the used areas of the reference frames, the pixel blocks in the unused area of the input frame may not be coded, or the unused area of the input frame may be filled with gray, white, or black pixel blocks.