| 摘要 |
A method and apparatus for memory-efficient decoding of frame chroma of progressive frames. During the display of a first field of the frame, lines of interpolated chroma values are calculated for both even and odd field lines. The lines of interpolated values for the first field are generated by applying a two-tap filter with coefficients (+E,fra 1/4+EE , +E,fra 3/4+EE ) to corresponding lines of chroma samples, and the lines of interpolated values for the second field are generated by applying a two-tap filter with coefficients (+E,fra 3/4+EE , +E,fra 1/4+EE ) to the corresponding lines of chroma samples. The lines of first field interpolated values are displayed with the first field, while a given even line of second field interpolated values is written to memory locations occupied by a line of chroma samples used to generate the given line. The other line of chroma samples used to generate the given line of second field interpolated values is allowed to be overwritten with additional progressive frame data, such that one line of decoder memory is freed up for each pair of displayed lines. This permits the frame chroma decoding process to be performed utilizing a total memory capacity of only 2.5 framestores. The odd lines of second field interpolated values are generated by averaging two of the previously-stored adjacent even lines of second field interpolated values, such that decoded video quality degradation is minimized.
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