| 摘要 |
A video decoder system for reconstructing, storing and retrieving bidirectionally predictive-coded (B) frames for display including pull-down conversion includes a reconstruction unit for reconstructing the frames, where the reconstruction unit reconstructs the top-upper field of every other frame twice. The frame is conceptually divided into four sections, including top-upper, top-lower, bottom-upper and bottom-lower sections. A memory having only three segments for storing pixel data is provided, where each segment is sized to store any one of the frame sections. A segmentor receives and separates the pixel data according to the top and bottom fields for each section of each frame, and stores pixel data from the top field into one segment pixel data from the bottom field into another segment. The segrnentor initially selects any two segments for the upper half of the first frame, and then selects a segment being retrieved for display and the third segment for the bottom half of the first frame. Thereafter, the segmentor selects the segment currently being retrieved for display and whichever segment contains pixel data that has already been retrieved and that will not be re-displayed. The segmentor also selects one segment for receiving the upper portion of the top field being reconstructed again for pull-down, which is that segment currently being retrieved for display. The decoder system also includes retrieval circuitry for retrieving pixel data from one of said three segments at a time for interlaced display.
|
