Motion picture encoding system wherein image quality is maximized using inter-frame and intra-frame encoding

Claim 1

A motion picture encoding system for either intra-frame encoding or forward, rearward and bi-directional predictive inter-frame encoding a motion picture which includes a sequence of frames, comprising: a means for encoding a given frame X by one of either intra-frame encoding or forward predictive inter-frame encoding; means for forward predictive encoding for a first case an (N-1)th frame and then for a second case an Nth frame, where N is a positive integer greater than X; means for bi-directional inter-frame encoding for the first case each frame of a sequence of frames between said given frame X and the (N-1)th frame and then for the second case each frame of a sequence of frames between said given frame X and the Nth frame; means for determining an estimate of the generated data quantity for frames encoded according to the first case and producing a corresponding signal D(N-1) corresponding thereto and for determining an estimate of the generated data quantity for frames encoded according to the second case and producing a corresponding signal D(N) corresponding thereto; and means for comparing the quantities D(N-1)/(N-1) and D(N)/N and forward predictive inter-frame encoding the (N-1)th frame and bidirectional inter-frame encoding frames in the motion picture between said given frame X and the (N-1)th frame if: {D(N-1)/(N-1)}<{D(N)/N-1} and otherwise forward predictive inter-frame encoding the (N)th frame and bidirectional inter-frame encoding the frames in the motion picture between said given frame X and the Nth frame.