Abstract: 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.

Abstract: 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 first frequency bins and a second watermark layer having second 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 to cause different combinations of watermark symbols that include one watermark symbol from each watermark layer to share a first number of frequency bins, the first number to be less than a number of watermark symbols in the different combinations; and generate a second distribution scheme to map the watermark symbols.

Abstract: 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.

Abstract: Apparatus, systems, articles of manufacture, and methods are disclosed for multiple scrambled layers for audio watermarking.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Systems, methods, apparatus, and articles of manufacture to improve timestamp transition resolution of watermarks are disclosed.

Abstract: Systems, methods, apparatus, and articles of manufacture to improve timestamp transition resolution of watermarks are disclosed.

Abstract: 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.

Abstract: 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.

Abstract: Apparatus, systems, articles of manufacture, and methods are disclosed for multiple scrambled layers for audio watermarking.

Abstract: 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.

Abstract: Systems, methods, apparatus, and articles of manufacture to improve timestamp transition resolution of watermarks are disclosed.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.