The Nielsen Comapny (us), LLC

Sadhana Gupta

Vladimir Kuznetsov

David Gish

Wendell D Lynch

Alan R Neuhauser

Ken Joseph Frett

Venugopal Srinivasan

Alexander Pavlovich Topchy

Example apparatus disclosed herein include a watermark detector to detect watermarks in a media signal. Disclosed example apparatus also include a controller to operate the watermark detector to (1) detect a first watermark in the media signal, and (2) cycle between sleep intervals and active intervals based on a repetition rate of the watermarks in the media signal to perform a detection operation for a second watermark at a second location in the media signal relative to a first location of the first watermark in the media signal. In some examples, the controller is to search a buffer of prior detected watermark symbols to detect a third watermark at a third location prior to the second location in the media signal in response to the second watermark not being detected at the second location in the media signal.

Power efficient detection of watermarks in media signals

Example methods and apparatus to improve timestamp transition resolution of watermarks are disclosed. A disclosed example apparatus is to determine an initial resolution for timestamp transitions based on a first number of time units between first ones of watermarks detected in media, and determine an updated resolution for the timestamp transitions based on a predicted timestamp transition window and a second number of time units between second ones of the watermarks detected in the media, the second ones of the watermarks to be subsequent to the first ones of the watermarks in the media, the predicted timestamp transition window associated with the initial resolution for timestamp transitions, the updated resolution for the timestamp transitions corresponding to a third number of time units, the third number of time units less than the second number of time units.

Systems and methods to improve timestamp transition resolution

Apparatus, systems, articles of manufacture, and methods are disclosed for multiple scrambled layers for audio watermarking. An example system includes a processor to execute instructions to: divide the watermark into a plurality of watermark symbols; map the watermark symbols to a plurality of frequency bins according to a first distribution scheme to create a first watermark layer having a first combination of the frequency bins and a second watermark layer having a second combination of the frequency bins, subsets of adjacent ones of the plurality of frequency bins grouped into a corresponding plurality of frequency clumps; determine a sequence for shifting watermark symbols between the frequency clumps to cause different combinations of watermark symbols that include one watermark symbol from each watermark layer to share up to a first number of frequency bins, the first number of frequency bins to be less than a number of watermark symbols in respective ones of the different combinations; and generate a second distribution scheme to map the watermark symbols in accordance with the sequence.

Multiple scrambled layers for audio watermarking

A method for generating a signature is disclosed. As part of the method, a first number of bits are identified in respective rows of an audio signature matrix that are determined to be the strongest bits in the row, bits of the audio signature matrix are replaced with respective cells having values depending on whether the respective bits are included in the first number of bits, a set of uniformly distributed numbers are generated within a range of numbered locations corresponding to cells of the audio signature matrix; numerical distances are determined, from respective numbers in the set of uniformly distributed numbers, to the numbered locations of the matrix, associated with nearest occurrences of a first value. A set of integers is generated based on the distances.

Methods and apparatus for audio signature generation and matching

Example apparatus to improve timestamp transition resolution of watermarks are disclosed. A disclosed example apparatus is to decode timestamps in respective ones of detected watermarks, estimate a first transition window indicative of a transition between a first time period to a second time period based on a first one of the timestamps and a second one of the timestamps, and when the first transition window does not satisfy a threshold, estimate a second transition window indicative of a transition between the second time period and a third time period based on the second one of the timestamps and a third one of the timestamps. The disclosed example apparatus is also to determine a first mapped transition window based on an intersection of the first transition window and the second transition window, and set the first mapped transition window as a reference time transition window for subsequent time periods.

Systems, methods, apparatus, and articles of manufacture to improve timestamp transition resolution of watermarks are disclosed. An example system includes a processor to: identify a first transition window between a first watermark detected in media and a second watermark detected in the media; calculate a first number of time units between the first watermark and the second watermark; when the first number of time units is greater than a threshold, set the first transition window as a first reference transition window, and map the first reference transition window forward by a second number of time units; identify a second transition window between the second watermark and a third watermark detected in the media; calculate a third number of time units between the second watermark and the third watermark; when the third number of time units is greater than the threshold, calculate a fourth number of time units included in an overlap between the first reference transition window and the second transition window, and when the fourth number of time units is less than or equal to the threshold, set the overlap between the first reference transition window and the second transition window as an established time transition.

Methods, apparatus, systems and articles of manufacture (e.g., physical storage media) to implement power efficient detection of watermarks in media signals are disclosed. Example metering apparatus disclosed herein include detector means for detecting watermarks in a media signal. Disclosed example metering apparatus also include controller means for operating the detector means to (1) detect a first watermark in the media signal, and (2) cycle between sleep intervals and active intervals to detect a second watermark at a second location in the media signal relative to a first location of the first watermark in the media signal after the first watermark has been verified.

Apparatus, systems, articles of manufacture, and methods are disclosed for multiple scrambled layers for audio watermarking. An example system includes a scrambler executing instructions to: divide a watermark into a plurality of watermark symbols; map the watermark symbols to a plurality of frequency bins in a plurality of frequency clumps according to a first distribution scheme to create a first watermark layer having a first combination of the frequency bins and a second watermark layer having a second combination of the frequency bins, the first combination of the frequency bins and the second combination of the frequency bins partially overlap. The scrambler also is to determine a sequence for shifting watermark symbols among the frequency bins, and generate a second distribution scheme to map the watermark symbols in accordance with the sequence. The example system also includes a transceiver to communicate the second distribution scheme to a device.

Systems, methods, apparatus, and articles of manufacture to improve timestamp transition resolution of watermarks are disclosed. An example system includes a watermark detector to detect watermarks in media and a decoder to decode timestamps from respective ones of the watermarks. The example system also includes a timestamp transition resolution enhancer to: (a) estimate, based on the timestamps, a coarse transition window between two time periods of the media; (b) map a prior transition window estimate to the estimate of (a); (c) determine a fine transition window estimate based on an overlap between the estimate of (a) and (b); (d) compare the fine transition window estimate of (c) to a threshold; (e) repeat (a) through (d) for successive time periods of the media using the fine transition window estimate of (c) as the prior transition window estimate of (b) until the fine transition window estimate of (c) satisfies the threshold; and (f) set the fine transition window estimate to be an established moment of transition between time periods of the media when the estimate of (c) satisfies the threshold.

Systems, methods, apparatus, and articles of manufacture to improve timestamp transition resolution of watermarks are disclosed. An example system includes a watermark detector to detect watermarks and a decoder to decode timestamps in respective ones of the watermarks. The example system also includes a timestamp transition resolution enhancer that estimates a first transition window indicative of a transition between a first time period to a second time period based on a first one of the timestamps and a second one of the timestamps. The timestamp transition resolution enhancer also estimates, when the first transition window does not satisfy a threshold, a second transition window indicative of a transition between the second time period and a third time period based on the second timestamp and a third one of the timestamps. In addition, the timestamp transition resolution enhancer determines a first mapped transition window based on an intersection of the first transition window and the second transition window, and sets the first mapped transition window as a reference time transition window for subsequent time periods.

Methods, apparatus, systems and articles of manufacture (e.g., physical storage media) to implement power efficient detection of watermarks in media signals are disclosed. Example watermark detection methods disclosed herein include operating a watermark detector in a first operating mode to detect a first watermark in a media signal. Disclosed example watermark detection methods also include, in response to the first watermark being verified, operating the watermark detector in a second operating mode in which the watermark detector cycles between sleep intervals and active intervals to detect a second watermark at a second location in the media signal relative to a first location of the first watermark in the media signal.

Methods, apparatus, systems and articles of manufacture (e.g., physical storage media) to implement power efficient detection of watermarks in media signals are disclosed. Example watermark detection methods disclosed herein include initiating a first search interval in which to attempt to detect watermarks in a media signal. Disclosed example watermark detection methods also initiating a sleep mode upon expiration of the first search interval in response to no valid watermarks being detected during the first search interval. Disclosed example watermark detection methods further include, upon expiration of a first sleep interval after initiation of the sleep mode, initiating a second search interval.

Growing community of inventors

Columbia, MD, United States of America

Sadhana Gupta