# US 11,451,884 B2 · Methods and apparatus to extend a timestamp range supported by a watermark > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,451,884 B2 - Document ID: US11451884B2 - Status: Granted - Kind: B2 - Application number: 17/332,643 - Filed: 2021-05-27 - Published: 2021-09-16 - Granted: 2022-09-20 - Earliest claimed: 2018-07-02 - Assignees: The Nielsen Company (US), LLC - Applicants: The Nielsen Company (US), LLC - Inventors: Vladimir Kuznetsov; Alexander Topchy - Web page: https://patentgrep.com/patent/US11451884B2 ## CPC - H04N 21/812: {involving advertisement data (advertising per se G06Q30/02)} - H04N 21/8358: involving watermark {(protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467)} - H04N 21/23892: {involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level} - H04N 21/2407: {Monitoring of transmitted content, e.g. distribution time, number of downloads (arrangements for monitoring programmes for broadcast or for distribution combined with broadcast H04H20/14)} - H04N 21/8352: involving content or source identification data, e.g. Unique Material Identifier [UMID] - H04N 21/8547: involving timestamps for synchronizing content - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Methods, apparatus, systems and articles of manufacture to extend a time range supported by a watermark are disclosed. Example watermark encoding apparatus disclosed herein determine which one of a plurality of timestamp cycles is to be represented by a timestamp of a watermark. Disclosed example apparatus also swap at least two symbols of the watermark when the timestamp is to represent a second one of the timestamp cycles, but do not swap the at least two symbols of the watermark when the timestamp is to represent a first one of the timestamp cycles. Disclosed example apparatus further embed the watermark in a first piece of media. ## Claims ### Claim 1 A watermark encoding apparatus comprising: at least one processor; computer readable instructions; and at least one processor to execute the instructions to: determine which one of a plurality of timestamp cycles is to be represented by a timestamp of a watermark; swap at least two symbols of the watermark when the timestamp is to represent a second one of the timestamp cycles, but not swap the at least two symbols of the watermark when the timestamp is to represent a first one of the timestamp cycles, the watermark including a first set of symbols representing data and a second set of symbols representing the timestamp, the first set of symbols including a first subset of symbols and a second subset of symbols, respective ones of the second subset of symbols to be determined from corresponding ones of the first subset of symbols based on another symbol not included in the first and second subsets of symbols, and the at least two symbols to be swapped are included in one of the first subset of symbols or the second subset of symbols, but not both of the first and second subsets of symbols; and embed the watermark in a first piece of media. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the timestamp has a timestamp range covering one timestamp cycle, and the watermark has a timestamp range covering the plurality of timestamp cycles. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein one timestamp cycle corresponds to a time period of substantially 28 days. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the data corresponds to an identifier of the piece of media. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein a number of timestamp cycles in the plurality of timestamp cycles is two. ### Claim 6 A watermark encoding apparatus comprising: means for determining which one of a plurality of timestamp cycles is to be represented by a timestamp of a watermark; means for swapping at least two symbols of the watermark when the timestamp is to represent a second one of the timestamp cycles, the means for swapping not to swap the at least two symbols of the watermark when the timestamp is to represent a first one of the timestamp cycles, the watermark including a first set of symbols representing data and a second set of symbols representing the timestamp, the first set of symbols including a first subset of symbols and a second subset of symbols, respective ones of the second subset of symbols to be determined from corresponding ones of the first subset of symbols based on another symbol not included in the first and second subsets of symbols, and the at least two symbols to be swapped are included in one of the first subset of symbols or the second subset of symbols, but not both of the first and second subsets of symbols; and means for embedding the watermark in a first piece of media. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein the timestamp has a timestamp range covering one timestamp cycle, and the watermark has a timestamp range covering the plurality of timestamp cycles. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein one timestamp cycle corresponds to a time period of substantially 28 days. ### Claim 9 (depends on 6) The apparatus of claim 6, wherein the data corresponds to an identifier of the piece of media. ### Claim 10 (depends on 6) The apparatus of claim 6, wherein a number of timestamp cycles in the plurality of timestamp cycles is two. ### Claim 11 A watermark decoding apparatus: at least one processor; computer readable instructions; and at least one processor to execute the instructions to: determine whether a first sequence of symbols of a decoded watermark obtained from a first piece of media is valid; swap at least two symbols of the decoded watermark to determine a second sequence of symbols when the first sequence of symbols is not valid; when the first sequence of symbols is valid, associate the decoded watermark with a first one of a plurality of timestamp cycles; and when the first sequence of symbols is not valid, associate the decoded watermark with a second one of the plurality of timestamp cycles when the second sequence of symbols is determined to be valid. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the first sequence of symbols includes a first set of symbols representing data and a second set of symbols representing a timestamp. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein the at least two symbols to be swapped to determine the second sequence of symbols are included in the first set of symbols representing the data. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the first set of symbols includes a first subset of symbols and a second subset of symbols, and the at least one processor is to: determine the first sequence of symbols is valid when respective ones of the second subset of symbols are related to corresponding ones of the first subset of symbols based on another symbol not included in the first and second subsets of symbols; and determine the first sequence of symbols is not valid when respective ones of the second subset of symbols are not related to corresponding ones of the first subset of symbols based on the another symbol not included in the first and second subsets of symbols. ### Claim 15 (depends on 12) The apparatus of claim 12, wherein the timestamp has a timestamp range covering a single timestamp cycle, and the decoded watermark has a timestamp range covering the plurality of timestamp cycles. ### Claim 16 A watermark decoding apparatus comprising: means for determining whether a first sequence of symbols of a decoded watermark obtained from a first piece of media is valid; means for swapping at least two symbols of the decoded watermark to determine a second sequence of symbols when the first sequence of symbols is not valid; and means for associating the decoded watermark with one of a plurality of timestamp cycles, the means for associating to: associate the decoded watermark with a first one of the plurality of timestamp cycles when the first sequence of symbols is valid; and when the first sequence of symbols is not valid, associate the decoded watermark with a second one of the plurality of timestamp cycles when the second sequence of symbols is determined to be valid. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the first sequence of symbols includes a first set of symbols representing data and a second set of symbols representing a timestamp. ### Claim 18 (depends on 17) The apparatus of claim 17, wherein the at least two symbols to be swapped to determine the second sequence of symbols are included in the first set of symbols representing the data. ### Claim 19 (depends on 18) The apparatus of claim 18, wherein the first set of symbols includes a first subset of symbols and a second subset of symbols, and the means for determining is to: determine the first sequence of symbols is valid when respective ones of the second subset of symbols are related to corresponding ones of the first subset of symbols based on another symbol not included in the first and second subsets of symbols; and determine the first sequence of symbols is not valid when respective ones of the second subset of symbols are not related to corresponding ones of the first subset of symbols based on the another symbol not included in the first and second subsets of symbols. ### Claim 20 (depends on 17) The apparatus of claim 17, wherein the timestamp has a timestamp range covering a single timestamp cycle, and the decoded watermark has a timestamp range covering the plurality of timestamp cycles.