# US 2013/0159805 A1 · Error Concealment > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0159805 A1 - Document ID: US20130159805A1 - Status: Published application - Kind: A1 - Application number: 13/682,073 - Filed: 2012-11-20 - Published: 2013-06-20 - Earliest claimed: 2009-05-01 - Assignees: Cambridge Silicon Radio Limited - Inventors: Xuejing Sun; Sameer Gadre; Scott Plude - Web page: https://patentgrep.com/patent/US20130159805A1 ## CPC - G06F 11/08: Error detection or correction by redundancy in data representation, e.g. by using checking codes - H04L 1/0047: {Decoding adapted to other signal detection operation (in conjunction with sequence estimation or equalization H04L25/03286)} - H04L 1/0072: {Error control for data other than payload data, e.g. control data} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method and apparatus for selectively replacing damaged portions of a data stream. The method comprises analyzing the data stream to identify damaged portions therein; selecting a damaged portion for replacement; and replacing the selected damaged portion. The selected damaged portion is selected for replacement in dependence on a rate of replacement, the rate of replacement being that at which previous portions of the data stream have been replaced. ## Claims ### Claim 1 A method of selectively replacing damaged portions of a data stream, the method comprising: for each damaged portion, estimating an error rate of the data stream; and applying a pre-defined algorithm to determine whether to replace the damaged portion, wherein the algorithm: (a) causes the output of the damaged portion if the estimated error rate is above a threshold; and (b) has a propensity to cause the output of a replacement portion in place of the damaged portion if the estimated error rate is below the threshold. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein if the estimated error rate is below the threshold, the algorithm is dependent on at least one criterion, wherein said at least one criterion is the level of degradation of the damaged portion and wherein a level of degradation lower than a threshold level promotes output of the damaged portion. ### Claim 3 (depends on 1) The method as claimed in claim 1, wherein if the estimated error rate is below the threshold, the algorithm is dependent on at least one criterion, wherein said at least one criterion is the level of degradation of the damaged portion and wherein a level of degradation higher than a threshold level promotes output of the replacement portion in place of the damaged portion. ### Claim 4 (depends on 1) The method as claimed in claim 1, wherein if the estimated error rate is below the threshold, the algorithm is dependent on at least one criterion, wherein said at least one criterion is whether the damaged portion has a property characteristic of noise, wherein the damaged portion having a property characteristic of noise promotes output of the damaged portion. ### Claim 5 (depends on 1) The method as claimed in claim 1, wherein if the estimated error rate is below the threshold, the algorithm is dependent on at least one criterion, wherein said at least one criterion is whether the damaged portion has a property characteristic of noise, wherein the damaged portion not having a property characteristic of noise promotes output of the replacement portion in place of the damaged portion. ### Claim 6 (depends on 1) The method as claimed in claim 1, wherein if the estimated error rate is below the threshold, the algorithm is dependent on at least one criterion, wherein said at least one criterion is whether the damaged portion comprises a click, wherein the damaged portion comprising a click promotes the selection of the damaged portion for replacement, replacement of the selected damaged portion with a replacement portion, and output of the replacement portion for the damaged portion. ### Claim 7 (depends on 6) The method as claimed in claim 6 wherein the replacement portion is identical to the damaged portion except in a region localized to the click position. ### Claim 8 (depends on 6) The method as claimed in claim 6 further comprising: determining if the damaged portion comprises a click by comparing the energy of the damaged portion to the energy of a portion proximal to the damaged portion. ### Claim 9 (depends on 1) The method as claimed in claim 1, wherein the output of a replacement portion in place of the damaged portion comprises the steps of: estimating a pitch period of the damaged portion; and forming a replacement portion for outputting by the algorithm, wherein the replacement portion is formed in dependence on the estimated pitch period. ### Claim 10 (depends on 1) The method as claimed in claim 1, further comprising: analyzing segments of the data stream to identify those segments consisting of more than a first number of samples; splitting each segment consisting of more than the first number of samples into portions, at least one of the portions consisting of up to the first number of samples. ### Claim 11 A method of selectively replacing damaged portions of a data stream, the method comprising: for each damaged portion, estimating an error rate of the data stream; and applying a pre-defined algorithm to determine whether to replace the damaged portion, wherein the algorithm: (a) causes the output of a replacement portion in place of the damaged portion if the estimated error rate is below the threshold; and b) has a propensity to cause the output of the damaged portion if the estimated error rate is above a threshold. ### Claim 12 (depends on 11) The method as claimed in claim 11, wherein if the estimated error rate is above the threshold, the algorithm is dependent on at least one criterion, wherein said at least one criterion is the level of degradation of the damaged portion and wherein a level of degradation lower than a threshold level promotes output of the damaged portion. ### Claim 13 (depends on 11) The method as claimed in claim 11, wherein if the estimated error rate is above the threshold, the algorithm is dependent on at least one criterion, wherein said at least one criterion is the level of degradation of the damaged portion and wherein a level of degradation higher than a threshold level promotes output of the replacement portion in place of the damaged portion. ### Claim 14 (depends on 11) The method as claimed in claim 11, wherein if the estimated error rate is above the threshold, the algorithm is dependent on at least one criterion, wherein said at least one criterion is whether the damaged portion has a property characteristic of noise, wherein the damaged portion having a property characteristic of noise promotes output of the damaged portion. ### Claim 15 (depends on 11) The method as claimed in claim 11, wherein if the estimated error rate is above the threshold, the algorithm is dependent on at least one criterion, wherein said at least one criterion is whether the damaged portion has a property characteristic of noise, wherein the damaged portion not having a property characteristic of noise promotes output of the replacement portion in place of the damaged portion. ### Claim 16 (depends on 11) The method as claimed in claim 11, wherein if the estimated error rate is above the threshold, the algorithm is dependent on at least one criterion, wherein said at least one criterion is whether the damaged portion comprises a click, wherein the damaged portion comprising a click promotes the selection of the damaged portion for replacement, replacement of the selected damaged portion with a replacement portion, and output of the replacement portion for the damaged portion. ### Claim 17 (depends on 16) The method as claimed in claim 16 wherein the replacement portion is identical to the damaged portion except in a region localized to the click position. ### Claim 18 (depends on 16) The method as claimed in claim 16 further comprising: determining if the damaged portion comprises a click by comparing the energy of the damaged portion to the energy of a portion proximal to the damaged portion. ### Claim 19 (depends on 11) The method as claimed in claim 11, wherein the output of a replacement portion in place of the damaged portion comprises the steps of: estimating a pitch period of the damaged portion; and forming a replacement portion for outputting by the algorithm, wherein the replacement portion is formed in dependence on the estimated pitch period. ### Claim 20 (depends on 11) The method as claimed in claim 11, further comprising: analyzing segments of the data stream to identify those segments consisting of more than a first number of samples; splitting each segment consisting of more than the first number of samples into portions, at least one of the portions consisting of up to the first number of samples.