Digital video signal recorder and reproducer

Claim 2

A digital video signal recorder and reproducer comprising: bit rate reduction encoding means for subjecting a digital video signal to bit rate reduction; copy input means for digital copy inputting an error corrected signal under a state of being subjected to bit rate reduction; recording means for recording a signal which is obtained by adding the information about said digital video signal to the signal subjected to bit rate reduction on a recording medium on a specified length block by block basis; error correcting means for correcting an error of a signal reproduced from the recording medium; and copy output means for digital copy outputting the error corrected signal under a state of being subjected to bit rate reduction.

Claim 3

An apparatus according to Claim 1, wherein the error correcting means conceals an error which has been detected but cannot be corrected.

Claim 4

An apparatus according to Claim 2, wherein the copy output means outputs a signal under a state of addition of the information about the digital signal to be copied, and the recording means records a data as is when the data is not required to be modified of its contents.

Claim 5

An apparatus according to Claim 2, wherein the copy output means carries out encoding of an error correcting code for correcting or detecting an error in a channel for copy signal, and the copy input means carries out decoding of the error correcting code.

Claim 6

An apparatus according to Claim 2, wherein the recording means carries out protection of a normally inputted signal, and modifies a condition of protection of a copy inputted signal.

Claim 7

A digital video signal recorder and reproducer comprising: bit rate reduction encoding means for subjecting a digital video signal to bit rate reduction by constituting 1 page of a digital video signal by 1 field or a plurality of fields and forming the data into blocks by dividing the data in each page; recording means for recording a signal which is obtained by adding information about said digital video signal to the signal subjected to bit rate reduction on a recording medium a specified length block by block basis; error correcting means for correcting and/or detecting an error of a signal reproduced from the recording medium; decision means for judging as to which of a data of a reference block on the same position 1 page before or a data of a reference block on the same position 1 page after has a stronger correlation with a data in a block in which an error has been detected, though no error can be corrected with the error correcting means; and block replacing means for replacing the block in which the error has been detected with a reference block selected by the decision means.

Claim 8

A digital video signal recorder and reproducer comprising: bit rate reduction encoding means for subjecting a digital video signal to bit rate reduction by constituting 1 page of a digital video signal by 1 field or a plurality of fields and forming the data into blocks by dividing the data in each page; recording means for recording a signal which is obtained by adding information about said digital video signal to the signal subjected to bit rate reduction on a recording medium a specified length block by block basis; error correcting means for correcting and/or detecting an error of a signal reproduced from the recording medium; decision means for judging as to which of a data of a reference block on the same position 1 page before or a data of a reference block on the same position 1 page after has a stronger correlation with a data in a block in which an error has been detected, though no error can be corrected with the error correcting means; and block replacing means for replacing the block in which the error has been detected with a reference block selected by the decision means.

Claim 9

A device according to Claim 6, wherein the bit rate reduction encoding means separates the inputted digital video signal to significant components and non-­significant components.

Claim 10

A device according to Claim 7, wherein replacement is always made with the block one page before by the replacing means.

Claim 11

A device according to Claim 7, wherein only the concealment information in the block one page after is detected by the detecting means.

Claim 12

A device according to Claim 7, wherein the decision means judges an inter-page correlation on presumption by using the data in the block in which error has been detected.

Claim 13

A device according to Claim 7, wherein the decision means performs judgement by using results of comparison between the significant components of the block in which the error has been detected and the corresponding significant components of the reference blocks located in the same position on the screen one page before and one page after.

Claim 14

A device according to Claim 11, wherein the decision means compares a sum of absolute values of differences between the significant components of the block in which the error has been detected and the significant components of the reference block located in one page before said block and a sum of absolute values of differences between the significant components of the block in which the error has been detected and the corresponding significant components of the reference block located in one page after said block, and selects the one having the smaller value thereof.

Claim 15

A device according to Claim 7, wherein the decision means performs judgement by using results of comparison on the respective corresponding significant components in which no error has been detected and which are in the respective neighboring blocks neighboring to the block in which the error has been detected and the reference blocks which are one page before and one page after said block on the same position on the screen.

Claim 16

A device according to Claim 13, wherein the decision means compares the average of the absolute values of the difference between the respective significant components in the blocks neighboring to the block in which error has been detected and the corresponding significant components in the respective neighboring blocks to the reference block one page before said block of which no error has been detected in either of them and the average of the absolute values of the difference between the respective significant components in the blocks neighboring to the block in which error has been detected and the corresponding significant components in the respective neighboring blocks to the reference block one page after said block of which no error has been detected in either of them, and selects one having the smaller value thereof.

Claim 17

A device according to Claim 7, wherein the decision means performs judgement by the inter-page correlation of the block adjacent to the block in which error has been detected.

Claim 18

A device according to Claim 7, wherein the decision means performs judgement by using the result of comparison made only on the one in which no error has been detected out of the respective significant components of the related page and the corresponding significant components of one page before totally, and the result of comparison made only on the block in which no error has been detected in either of the respectrive significant components of the related page and the corresponding significant components of one page after totally.

Claim 19

A device according to Claim 16, wherein the decision means compares the average of the absolute values of the difference between the one in which no error has been detected out of the total significant components of the related page and the total significant components of 1 page before said page with the average of the absolute values of the difference between the one in which no error has been detected out of the total significant components of the related page and the total significant components of 1 page after said page, and selects the one having the smaller value thereof.

Claim 20

A digital video signal recorder and reproducer comprising: bit rate reduction means for constituting one page of the digital video signal by one field or a plurality of fields, dividing the data in each page to form into blocks and bit rate reduction encoding; recording means for recording on a recording medium by the block of specified length said bit rate reduction encoded signal provided additionally with information concerning said digital video signal and concealment information showing as to whether each block is the concealed block or not, and if it is the concealed block, with what page block it has been replaced; error correcting means for carrying out correction and/or detection of the error of the signal reproduced from the recording medium; detecting means for detecting the concealment information in the reference block located in the same position one page before the block in which the error has been detected and the concealment information in the reference block located in the same position one page after the block in which the error has been detected; first replacing means for controlling the replacement by such block that has been known that there is a block previously replaced by using the block which is at present error is detected by the detecting means; deciding means to judge, in the case where there does not exist the block replaced previously by using the block in which error has at present been detected by the detecting means, as to with which of the reference block located in the same position one page before or the reference located in the same position one page after the block in which error has been detected has the stronger correlation; second replacing means for replacing the block in which error has been detected by the reference block selected by the deciding means; and concealment information modifying means for modifying the concealment information in each block.

Claim 21

A digital video signal recorder and reproducer comprising: bit rate reduction means for constituting one page of the digital video signal by one field or a plurality of fields, dividing the data in each page to form into blocks and bit rate reduction encoding; recording means for recording on a recording medium by the block of specified length said bit rate reduction encoded signal provided additionally with information concerning said digital video signal and concealment information showing as to whether each block is the concealed block or not, and if it is the concealed block, with what page block it has been replaced; error correcting means for carrying out correction and/or detection of the error of the signal reproduced from the recording medium; detecting means for detecting the concealment information in the reference block located in the same position one page before the block in which the error has been detected and the concealment information in the reference block located in the same position one page after the block in which the error has been detected; first replacing means for controlling the replacement by such block that has been known that there is a block previously replaced by using the block which is at present error is detected by the detecting means; deciding means to judge, in the case where there does not exist the block replaced previously by using the block in which error has at present been detected by the detecting means, as to with which of the reference block located in the same position one page before or the reference located in the same position one page after the block in which error has been detected has the stronger correlation; second replacing means for replacing the block in which error has been detected by the reference block selected by the deciding means; and concealment information modifying means for modifying the concealment information in each block.

Claim 22

A device according to Claim 18, wherein the bit rate reduction means separates the inputted digital video signal into significant components and non-­significant components.

Claim 23

A device according to Claim 19, wherein replacement is performed at all times with a block one page before by the second replacing means.

Claim 24

A device according to Claim 19, wherein only the concealment information in the block one page after is detected by the detecting means.

Claim 25

A device according to Claim 19, wherein the deciding means judges by surmising the inter-page correlation by using the data in the block in which error has been detected.

Claim 26

A device according to Claim 19, wherein the deciding means judges by using results of comparison between the significant component of the block in which error has been detected and the corresponding significant components of the reference blocks located in the same position on the screen one page before and one page after.

Claim 27

A device according to Claim 23, wherein the deciding means compares the sum of the absolute values of the difference between the significant components of the block in which the error has been detected and the significant components of the reference block located in one page before said block and the sum of the absolute values of the difference between the significant components of the block in which the error has been detected and the corresponding significant components of the reference block located in one page after said block, and selects the one having the smaller value thereof.

Claim 28

A device according to Claim 19, wherein the decision means performs judgement by using results of comparison on the respective corresponding significant components in which no error has been detected and which are in the respective neighboring blocks neighboring to the block in which the error has been detected and the reference blocks which are one page before and one page after said block on the same position on the screen.

Claim 29

A device according to Claim 25, wherein the decision means compares the average of the absolute values of the difference between the respective significant components in the blocks neighboring to the block in which error has been detected and the corresponding significant components in the respective neighboring blocks to the reference block one page before said block of which no error has been detected in either of them and the average of the absolute values of the difference between the respective significant components in the blocks neighboring to the block in which error has been detected and the corresponding significant components in the respective neighboring blocks to the reference block one page after said block in which no error has been detected in either of them, and selects one having the smaller value thereof.

Claim 30

A device according to Claim 19, wherein the decision means performs judgement by the inter-page correlation of the block adjacent to the block in which error has been detected.

Claim 31

A device according to Claim 19, wherein the decision means performs judgement by using the result of comparison made only on the one in which no error has been detected out of the respective significant components of the related page and the corresponding significant components of one page before totally, and the result of comparison made only on the block in which no error has been detected out of the respective significant components of the related page and the corresponding significant components of one page after totally.

Claim 32

A device according to Claim 28, wherein the decision means compares the average of the absolute values of the difference between the respective significant components of the related page and the corresponding significant components of one page before said page totally in which no error has been detected out of them with the average of the absolute values of the difference between the respective significant components of the related page and the corresponding significant components of one page after said page totally in which no error has been detected out of them, and selects the one having the smaller value thereof.