Patent ID: 11930194
Assignee: TEXAS INSTRUMENTS INCORPORATED
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 10:
11. A system for encoding a video stream, comprising:
an electronic memory to store input video frames; and
a circuit configured to:
down sample the input video frames by a down-sampling factor;
encode each of the down sampled frames as an intra-coded frame (I frame) or as a predictive coded frame (P frame) in a first encoding pass;
generate first pass mean motion vectors for the down sampled frames; and
encode each of the input video frames as an I frame, as a P frame, or as a bipredictive coded frame (B frame) in a second encoding pass by:
scaling the first pass mean motion vectors based on the down-sampling factor to generate scaled first pass mean motion vectors;
for each individual B frame, computing a second pass mean motion vector according to the scaled first pass mean motion vectors for the first pass coded frames to which the individual B frame is referenced and any intervening first pass coded frames; and
for the P frame, computing a second pass mean motion vector as a cumulative sum of the scaled first pass mean motion vectors for the first pass coded frames.