1. A computer implemented method of processing a series of video frames of video data, comprising the computer implemented steps of: encoding one or more portions of the video data using a first encoding process and one or more other portions of the video data using a feature-based encoding process by: processing a plurality of decoded video frames in the series to detect one or more instances of a candidate feature, said candidate feature being a region of pels exhibiting encoding complexity relative to neighboring pels; said detection including determining positional information for the instances of the candidate feature in the one or more decoded video frames, the positional information for a respective instance of the candidate feature including one or more of: a frame identifier for the respective instance of the candidate feature, a position within that respective frame, or a spatial perimeter of the respective instance of the candidate feature; determining, using a motion compensated prediction process, an instance of the candidate feature in a subject video frame in the series using the one or more decoded video frames, where said motion compensated prediction is initialized with the positional information from instances of the candidate feature in the decoded video frame; aggregating one or more of the candidate feature instances; transforming one or more of the candidate feature instances; forming a first feature-based model based on the aggregated, transformed candidate feature instances, the first feature-based model enabling prediction in the subject video frame of an appearance and a source position of a substantially matching feature instance, where the substantially matching feature instance is a key feature instance, the first feature-based model resulting in a feature-based encoding; comparing compression efficiency of the feature-based encoding to an encoding from the first video encoding process; and using results of the comparing step, applying feature-based encoding to portions of one or more of the video frames, and applying the first encoding process to other portions of the one or more video frames.