MPEG-2 video coding with an adaptive selection of scanning path and picture structure

In MPEG-2 video coding an interlaced frame can be encoded as either a frame-picture or two field-pictures. The selection of picture structure (frame/field) has a strong impact on picture quality. In order to achieve the best possible picture quality, an adaptive scheme is proposed to select the optimal picture structure on a frame by frame basis. The selection of picture structure is performed in connection with that of the optimal scanning path. First, the scanning path (zig-zag scan/alternate scan) is chosen based on a post-analysis of DCT-coefficients. Secondly, the optimal picture structure is selected for the next frame according to the chosen scanning path, i.e., a zig-zag scan corresponds to frame picture structure, while an alternate scan corresponds to field picture structure. Furthermore, the TM5 buffer control algorithm is extended to support coding with the adaptive frame/field picture structure. Finally, simulation results verify the adaptive scheme proposed.