Methods and apparatus for reducing the cost of video decoders

Abstract

Methods and apparatus for implementing video decoders at a reduced cost are described. The methods include data reduction techniques, simplified inverse quantization techniques, and dynamically varying the complexity of image enhancement operations, e.g., prediction filtering operations, as a function of whether luminance or chrominance data is being processed. In order to reduce data storage requirements, luminance and chrominance data corresponding to previously encoded images may be stored at different resolutions with, in some embodiments, chrominance data being stored at less than half the resolution of luminance data. In various embodiments, data representing portions of B frames which will not be displayed is identified and discarded, e.g., without performing a decoding operation thereon. Portions of I and P frames which will not be displayed are identified and decoded at a reduced resolution and/or using simplified inverse quantization techniques. The decoded I and P frame data is stored for use when making subsequent predictions if required. Another data reduction technique involves applying different amounts of data reduction, e.g., downsampling, to different image portions with no or little downsampling being performed on image portions located at or nearest to the image's center of interest as determined from information included in a received encoded bitstream.