Video signal processing circuit

A video signal processing circuit for performing error correction and error concealment on input video signal sample data, some of which contain errors and at least some of which are free of errors, comprising:

• error correcting means for correcting at least some of said errors and providing the resulting error corrected sample data, along with error flags indicating any sample data still containing errors at an output of said error correcting means, and
• error concealment means supplied with said error-corrected sample data provided at said output and said error flags for performing error concealment of said sample data which are indicated by said error flags to contain errors using other sample data which are in peripheral and/or time displaced relation to said sample data indicated by said error flags to still contain errors;
• said error concealment means having a plurality of error concealment operating modes and including selectable recursive replacement error concealment means for error-concealing said sample data indicated to contain error by replacing said sample data with said other sample data which has replaced sample data indicated to contain error,
• counting means for producing a count signal representing the number of times that the other sample data has been used to conceal error, and
• selecting means for selecting one of said error concealment operating modes in dependence upon the state of the error flags for said peripheral and/or time displaced sample data, said selecting means being operative to select the recursive concealment means to error-conceal said sample data indicated to contain error based upon the count signal.

A video signal processing circuit for performing error correction and error concealment on input video signal sample data, some of which contain errors and at least some of which are free of errors, comprising:

• error correction means for correcting at least some of said errors with the use of a product code employing at least a first and a second series of an error correction code of the input sample data and providing the resulting error corrected sample data, along with error flags indicating any sample data still containing errors at an output of said error correction means, said error correction means comprising gray flag producing means for setting a gray flag of the input sample data when the error correction capability of the error correction means using the second series of the error code is exceeded, and
• error concealment means supplied with said error corrected sample data provided at said output and said error flags for performing error concealment of said sample data which are indicated by said error flags to still contain errors using other sample data which are in peripheral and/or time displaced relation to said sample data indicated by said error flags to still contain errors,
• said error concealment means having a plurality of error concealment operating modes and including means for selecting one of said error concealment operating modes in dependence upon the state of the error flags for said peripheral and/or time displaced sample data;
• said error concealment means further including:
• comparison means for comparing the original sample data with error concealed data produced by the error concealment means to produce a difference signal representing a difference therebetween, and original sample data selection means for selecting the original sample data to be output in place of the error concealed data where the difference signal is within a predetermined acceptance threshold and the gray flag of said original sample data has been set.