Patent Document ID: 20020141502
Application ID: 09681423
Patent Flag: 0

Claim One:
1. A method for detecting errors in an motion-picture-experts group (MPEG) bitstream comprising: receiving a MPEG bitstream containing transmission errors; parsing the MPEG bitstream for a block within a macroblock; extracting block data for the block from the MPEG bitstream; decoding variable-length codewords in the block data to generate coefficients for the block; determining when an error-detection constraint is met by the coefficients and when the error-detection constraint is not met by the coefficients for the block; and when the error-detection constraint is met, transforming the coefficients to generate pixel data for the block for display; when the error-detection constraint is not met, signaling an error for the block and concealing the error by discarding the coefficients and not generating display data from the coefficients for the block, whereby an error in the block are detected by constraint checking of the coefficients for the block.