Methods of feature extraction of video sequences

A method for identifying a frame, comprising the steps of:

• identifying at least a first inter-coded frame and a second inter-coded frame in a compressed video bit-stream, wherein (i) the compressed video bit-stream corresponds to a video sequence having intra-coded and inter-coded frames, each of the inter-coded frames having a plurality of macro-blocks, the compressed bit-stream including a number of bits associated with each of the inter-coded frames representing a displacement from the associated inter-coded frame to a closest matching of the intra-coded frames, a respective portion of the number of bits being associated with each of the plurality of macro-blocks of that inter-coded frame and corresponding to a number of run lengths representing those of the plurality of macro-blocks of that inter-coded frame having the associated respective portion of the number of bits equaling less than a threshold, and (ii) the first and the second inter-coded frames are identified based on the number of bits associated with the first inter-coded frame and the number of bits associated with the second inter-coded frame;
• and
• identifying only the first inter-coded frame of the identified at least first and second inter-coded frames based on the number of run lengths associated with the first inter-coded frame.

A descriptor, stored on a computer readable memory, for identifying a frame, comprising:

• a number of bits of a compressed bit stream corresponding to a video sequence having intra-coded frames and inter-coded frames, each of the inter-coded frames including a plurality of macro-blocks, wherein the number of bits are associated with the plurality of macro-blocks of one of the inter-coded frames and represent a displacement from the one inter-coded frame to a closest matching of the intra-coded frames;
• and
• a value corresponding to run lengths of those of the plurality of macro-blocks of the one inter-coded frame having less than a threshold number of the associated bits.