1. A method of processing input video for motion based dynamic resolution encoding of segmented compressed video streams for multi bit rate video streaming using a computing device, the computing device comprising a processing unit and memory, the method comprising: with the computing device: encoding input video content in one or more segments, each segment comprising one or more groups of pictures, wherein the encoding comprises: for a group of pictures of the one or more groups of pictures, obtaining at least three encoding samples for varying resolution and quantization step size; establishing a model relating resolution, quantization step size and resulting encoded size for the group of pictures; calculating an average median motion vector value for the groups of pictures; deciding a video resolution and quantization step size based, at least in part, on the average median motion vector value, a motion threshold, and the model; and encoding the group of pictures with the decided video resolution and quantization step size.