Patent ID: 6275527
Filing Date: 2001-08-14
Classification: H04N

Abstract:
A method of encoding video data, comprising the steps of:Performing motion estimation on a sequence of frames, each frame comprising a plurality of blocks;classifying each frame as either an I frame, a P frame, or a B frame;determining the quantization step size for each block or group of blocks;selecting a threshold value for each block based upon the quantization step size;classifying each blocks as a zero quantized block or a non-zero quantized block using the selected threshold value;performing DCT, quantization, zig-zag scan, and variable length coding on the non-zero quantized blocks;skipping the DCT, quantization, zig-zag scan and variable length coding steps for the zero quantized blocks;performing DCT, quantization, zig-zag scan, and variable length coding on the given sequence of frames without skipping zero quantized blocks to generate an actual encoded result; andcomparing the actual encoded result with the result from only performing DCT, quantization, zig-zag scan and variable length coding on the non-zero quantized blocks within the sequence of frames to determine the accuracy provided by the selected threshold value.