Methods and apparatus to extend a timestamp range supported by a watermark

• US 10,448,123 B1
• Filed: 07/02/2018
• Issued: 10/15/2019
• Est. Priority Date: 07/02/2018
• Status: Active Grant

• Current Assignee: The Nielsen Company LLC (MOOD Media Corporation)
• Original Assignee: The Nielsen Company LLC (MOOD Media Corporation)
• Inventors: Topchy, Alexander, Kuznetsov, Vladimir
• Primary Examiner(s): Mengesha, Mulugeta
• Application Number:
  US16/025,805
• Time in Patent Office: 470 Days
• CPC Class Codes: H04N 21/23892 involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: 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
• CPC Class Codes: H04N 21/8352 involving content or source identification data, e.g. Unique Material Identifier [UMID]
• CPC Class Codes: 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
• CPC Class Codes: H04N 21/8547 involving timestamps for synchronizing content

Abstract

Methods, apparatus, systems and articles of manufacture (e.g., physical storage media) to extend a time range supported by a watermark are disclosed. Example watermark encoding apparatus disclosed herein include a timestamp cycle evaluator to determine which one of a plurality of timestamp cycles is to be represented by a timestamp of a watermark, the timestamp including a set of timestamp symbols. Disclosed example watermark encoding apparatus also include a symbol modifier to modify a subset of data symbols of the watermark based on a further timestamp symbol not included in the set of timestamp symbols of the timestamp, the further timestamp symbol identifying the one of the timestamp cycles to be represented by the timestamp of the watermark. Disclosed example watermark encoding apparatus further include a watermark embedder to embed the watermark in a first piece of media.

Claims

1. A watermark encoding apparatus comprising:

a timestamp cycle evaluator to determine which one of a plurality of timestamp cycles is to be represented by a timestamp of a watermark, the timestamp including a set of timestamp symbols, the watermark including a first subset of data symbols and a second subset of data symbols, respective ones of the second subset of data symbols to be determined from corresponding ones of the first subset of data symbols based on another data symbol not included in the first and second subsets of data symbols;

a symbol modifier to modify the first subset of data symbols of the watermark based on a further timestamp symbol not included in the set of timestamp symbols of the timestamp, but not to modify the second subset of data symbols based on the further timestamp symbol, the further timestamp symbol to identify the one of the plurality of timestamp cycles to be represented by the timestamp of the watermark, the data symbols of the watermark different from the timestamp symbols of the watermark; and

a watermark embedder to embed the watermark in a first piece of media.

2. 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.

3. The apparatus of claim 2, wherein one timestamp cycle corresponds to a time period of substantially 28 days.

4. The apparatus of claim 1, wherein a number of timestamp cycles in the plurality of timestamp cycles is two.

5. The apparatus of claim 1, wherein the data symbols represent an identifier of the piece of media.

6. The apparatus of claim 1, wherein to modify the first subset of data symbols, the symbol modifier is to exclusive-OR (XOR) respective ones of the first subset of data symbols with the further timestamp symbol.

7. A non-transitory computer readable medium comprising computer readable instructions which, when executed, cause a processor to at least:

determine which one of a plurality of timestamp cycles is to be represented by a timestamp of a watermark, the timestamp including a set of timestamp symbols, the watermark including a first subset of data symbols and a second subset of data symbols, respective ones of the second subset of data symbols to be determined from corresponding ones of the first subset of data symbols based on another data symbol not included in the first and second subsets of data symbols;

modify the first subset of data symbols of the watermark based on a further timestamp symbol not included in the set of timestamp symbols of the timestamp, but not to modify the second subset of data symbols based on the further timestamp symbol, the further timestamp symbol to identify the one of the plurality of timestamp cycles to be represented by the timestamp of the watermark, the data symbols of the watermark different from the timestamp symbols of the watermark; and

embed the watermark in a first piece of media.

8. The computer readable medium of claim 7, wherein the timestamp has a timestamp range covering one timestamp cycle, and the watermark has a timestamp range covering the plurality of timestamp cycles.

9. The computer readable medium of claim 8, wherein one timestamp cycle corresponds to a time period of substantially 28 days.

10. The computer readable medium of claim 7, wherein a number of timestamp cycles in the plurality of timestamp cycles is two.

11. The computer readable medium of claim 7, wherein the data symbols represent an identifier of the piece of media.

12. The computer readable medium of claim 7,

wherein to modify the first subset of data symbols, the instructions, when executed, cause the processor to exclusive-OR (XOR) respective ones of the first subset of data symbols with the further timestamp symbol.

13. A watermark encoding method comprising:

determining, by executing an instruction with a processor, which one of a plurality of timestamp cycles is to be represented by a timestamp of a watermark, the timestamp including a set of timestamp symbols, the watermark including a first subset of data symbols and a second subset of data symbols, respective ones of the second subset of data symbols being determined from corresponding ones of the first subset of data symbols based on another data symbol not included in the first and second subsets of data symbols;

modifying, by executing an instruction with the processor, the first subset of data symbols of the watermark based on a further timestamp symbol not included in the set of timestamp symbols of the timestamp, but not modifying the second subset of data symbols based on the further timestamp symbol, the further timestamp symbol identifying the one of the plurality of timestamp cycles to be represented by the timestamp of the watermark, the data symbols of the watermark different from the timestamp symbols of the watermark; and

embedding, by executing an instruction with the processor, the watermark in a first piece of media.

14. The method of claim 13, wherein the timestamp has a timestamp range covering one timestamp cycle, and the watermark has a timestamp range covering the plurality of timestamp cycles.

15. The method of claim 13, wherein a number of timestamp cycles in the plurality of timestamp cycles is two.

16. The method of claim 13, wherein the data symbols represent an identifier of the piece of media.

17. The method of claim 13, wherein the modifying of the first subset of data symbols includes combining respective ones of the first subset of data symbols with the further timestamp symbol based on an exclusive-OR (XOR) operation.

18. The method of claim 13, wherein one timestamp cycle corresponds to a time period of substantially 28 days.