Digital TV receiver decoder for e.g. improves the picture quality of a down converted video signal

摘要

The decoder receives data in block units, converts a format of the data into a format for display, memorizes and processes the memorized data and displays the processed data by carrying out the conversion of the format to include more vertical color signals than horizontal color signal. Memorizing and reproducing the data in downsampled data blocks with a given ratio to store the data. The luminance information in an 8 x 8 size data block (141) is inverse discrete cosine transformed (IDCT) and downsampled for 8 pels in the horizontal and vertical directions into a 4 x 4 size data block. The color information of the data block, however, is IDCT/downsampled for 8 pels in a horizontal direction into an 8 x 8 size data block. The video data having luminance information and color information downsampled into 4 x 4 and 8 x 8 respectively is added to the motion compensated data at an adder (143) and stored in a frame memory (144). The video data stored in the frame memory is further processed using the motion vectors and the downsampled compensated information is added at the adder. Thereby obtaining a downsampled video block to store in the frame memory. For presentation, the output of the frame memory is converted into a 4:2:2 format with a size of 720 pels/480 lines or 720 pels/360 lines at a format conversion unit (148). Assuming that we have a 16:9 image source, the size of 720 pels/480 lines is for wide TV display or a pan and scan type display on a 4:3 TV, and the size of 720 pels/360 lines is for a letter box type display on a 4:3 size TV.