Highly programmable chrominance filter for 4:2:2 to 4:2:0 conversion during MPEG2 video encoding

• Main Authors: NGAI AGNES YEE, VACHON MICHAEL PATRICK
• Format: Patent
• Language: English
• Published: 13.02.2001
• Edition: 7
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

A filter for downsampling input video having a first chrominance sampling to a second chrominance sampling. The input video has a Bitstream of data representing a sequence of picture frames, where each picture frame has a plurality of video lines. The filter has a means for choosing a downsampling mode from a list of available downsampling modes for the downsampling of the first chrominance sampling. The filter also has a means for dividing each picture frame into video line sets according to predetermined criteria for the particular downsampling mode chosen, where each video line set has at least two video lines. A means for assigning default downsampling coefficients for each of the video lines in the video line sets based upon the downsampling mode chosen is also provided in the filter. Lastly, the filter has a means for downsampling each video line set to a single video line having the second chrominance sampling. In a preferred embodiment, the first chrominance sampling is 4:2:2 and the second chrominance sampling is 4:2:0.