Device for correcting and concealing errors in a data stream, and video and/or audio reproduction apparatus comprising such a device

Claim 1

A device for correcting and concealing errors in a data stream which is organized in a succession of data blocks, each data block being converted into a code block consisting of code elements which are grouped according to an error protection code having at least error-correcting properties by addition of redundancy, the code elements being received from a medium as being systematically distributed over an interval which corresponds to the length of several data blocks, said device comprising: (a) an input means which includes a regrouping element for regrouping the code elements in code blocks; (b) a correction means coupled to said input means for reconstructing the associated data block from a regrouped code block while performing a correction, and forming a correction signal via a correction means signal output; (c) a concealing means for concealing, under the control of said correction signalling received by said correction means from said correction means signal output, a data element by replacing said data element with a supplementary data element; and (d) an output means coupled to outputs of said correction means and said concealing means for converting the corrected or substitute data elements into a continuous signal stream, wherein said concealing means supplements a data element for a code block having a predetermined sequence number within a succession of code blocks when the total number of corrections to be performed within said succession exceeds a predetermined limit corresponding to a maximum number of corrections capable utilizing said code, said concealing means remains inactive below said predetermined limit, and said correction means applies a corrected data element to the output device below said predetermined limit.

Claim 2

A device for correcting and concealing errors in a data stream which is organized in a succession of data blocks, each data block being converted into a code block consisting of code elements which are grouped according to an error protection code having at least error-correcting properties by addition of redundancy, the code elements being received from a medium as being systematically distributed over an interval which corresponds to the length of several data blocks, said device comprising: (a) an input means which includes a regrouping element for regrouping the code elements in code blocks; (b) a correction means coupled to said input means for reconstructing the associated data block from a regrouped code block while performing a correction, and forming a correction signal via a correction means signal output; (c) a concealing means for concealing, under the control of said correction signalling received by said correction means from said correction means signal output, a data element by replacing said data element with a supplementary data element; and (d) an output means coupled to outputs of said correction means and said concealing means for converting the corrected or substitute data elements into a continuous signal stream, wherein said concealing means supplements a data element for a code block having a predetermined sequence number within a succession of code blocks when the total number of corrections to be performed within said succession exceeds a predetermined limit corresponding to a maximum number of corrections capable utilizing said code, said concealing means remains inactive below said predetermined limit, and said correction means applies a corrected data element to the output device below said predetermined limit.

Claim 5

A device as claimed in any one of the claims 1 to 3, wherein the error-protection code has a minimum Hamming distance for given data element within 2 data blocks which deviates from that for other data elements.

Claim 6

A device as claimed in any one of the claims 1 to 3, further comprising a processing element for adding a standard word to a code block so as to enable detection of uniformly monovalent code blocks.