Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for delivering extended payloads with composite watermarks. Examples disclosed herein embed a first watermark into a media stream in accordance with a first watermark technology, where the first watermark includes a first indicator bit and a first payload. Disclosed examples also embed a second watermark into the media stream in accordance with a second watermark technology, where the second watermark includes a second indicator bit and a second payload. In some disclosed examples, the first indicator bit and the second indicator bit are to indicate whether the first payload and the second payload are to be combined when the first watermark and the second watermark are decoded.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for delivering extended payloads with composite watermarks. Examples disclosed herein embed a first watermark into a media stream in accordance with a first watermark technology, where the first watermark includes a first indicator bit and a first payload. Disclosed examples also embed a second watermark into the media stream in accordance with a second watermark technology, where the second watermark includes a second indicator bit and a second payload. In some disclosed examples, the first indicator bit and the second indicator bit are to indicate whether the first payload and the second payload are to be combined when the first watermark and the second watermark are decoded.

Abstract: A method includes receiving, into a microphone of a portable computing device, audio from a surrounding environment of the portable computing device. The method also includes classifying, by the portable computing device, the received audio as containing media content or as containing no media content. Classifying the received audio as containing media content or as containing no media content comprises determining whether the audio defines content emitted from a media player in the surrounding environment of the portable computing device. The method further includes, based on the classifying, controlling by the portable computing device whether to engage in an audio-identification process for determining an identity of the media content.

Abstract: 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.

Abstract: Methods and apparatus are disclosed for supplementing partially readable and/or inaccurate codes. An example apparatus includes a watermark analyzer to select a first watermark and a second watermark decoded from media; a comparator to compare a first decoded timestamp of the first watermark to a second decoded timestamp of the second watermark; and a timestamp adjuster to adjust the second decoded timestamp based on the first decoded timestamp of the second watermark when at least a threshold number of symbols of the second decoded timestamp match corresponding symbols of the first decoded timestamp.

Abstract: To extract an identifier value from a watermark in media content, a system initially determines the identifier by determining symbol values based on an evaluation of tone strength of each of multiple symbol time segments of the watermark. Further, the system assigns a quality level to the watermark, based on a count of errors in the determined symbol values in view of one or more watermark-structure rules. Still further, if the quality level is threshold low, then the system engages in an error correction process that takes into account, for each symbol time segment whose symbol value may be erroneous, whether that symbol time segment has a threshold strong tone combination that matches the tone combination of a corresponding symbol time segment in a verified watermark. And if the error correction process is successful, the system replaces the determined identifier value with the identifier value of the verified watermark.

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 are disclosed to determine whether audience measurement meters are co-located. An example apparatus is to, based on a difference between a first sampling time of a first entry of a first log and a second sampling time of a corresponding entry of a second log satisfying a first threshold, determine at least one matching instance of at least one first device identifier of the first entry and at least one second device identifier of the corresponding entry. Additionally, the example apparatus is to populate a variable with the at least one matching instance. The example apparatus is also to, based on a metric satisfying a second threshold, cause transmission of an alert indicating that a first meter and a second meter were co-located during generation of the first log and the second log, the metric based on the at least one matching instance.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for associating different watermarks detected in media. An example method disclosed herein includes determining whether a first watermark detected in a media signal is represented in a watermark data structure and associating the first watermark with a first media presentation record associated with a second watermark in response to the first watermark being associated in the watermark data structure with the second watermark. The example method further includes transmitting monitoring data including the first media presentation record to an audience measurement entity.

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 are disclosed for associating different watermarks detected in media. An example method disclosed herein includes determining whether a first watermark detected in a media signal is represented in a watermark data structure and associating the first watermark with a first media presentation record associated with a second watermark in response to the first watermark being associated in the watermark data structure with the second watermark. The example method further includes transmitting monitoring data including the first media presentation record to an audience measurement entity.

Abstract: 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.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for delivering extended payloads with composite watermarks. Examples disclosed herein embed a first watermark into a media stream in accordance with a first watermark technology, where the first watermark includes a first indicator bit and a first payload. Disclosed examples also embed a second watermark into the media stream in accordance with a second watermark technology, where the second watermark includes a second indicator bit and a second payload. In some disclosed examples, the first indicator bit and the second indicator bit are to indicate whether the first payload and the second payload are to be combined when the first watermark and the second watermark are decoded.

Abstract: Methods and apparatus are disclosed for supplementing partially readable and/or inaccurate codes. An example apparatus includes a watermark analyzer to select a first watermark and a second watermark decoded from media; a comparator to compare a first decoded timestamp of the first watermark to a second decoded timestamp of the second watermark; and a timestamp adjuster to adjust the second decoded timestamp based on the first decoded timestamp of the second watermark when at least a threshold number of symbols of the second decoded timestamp match corresponding symbols of the first decoded timestamp.

Abstract: Methods, apparatus, systems and articles of manufacture to extend a timestamp range supported by a watermark without breaking backwards compatibility are disclosed. An example watermark encoder includes a counter to increment symbols of a watermark timestamp and a controller to control the counter to increment the symbols of the watermark timestamp based on a key, the controller to cause the counter to restrict ones of the symbol values to increment over one of a first range of symbol values or a second range of symbol values based on a value of the key, the second range of symbol values different from the first range of symbol values.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to determine whether audience measurement meters are co-located. An example apparatus is to, based on a difference between a first sampling time of a first entry of a first log and a second sampling time of a corresponding entry of a second log satisfying a first threshold, determine at least one matching instance of at least one first device identifier of the first entry and at least one second device identifier of the corresponding entry. Additionally, the example apparatus is to populate a variable with the at least one matching instance. The example apparatus is also to, based on a metric satisfying a second threshold, cause transmission of an alert indicating that a first meter and a second meter were co-located during generation of the first log and the second log, the metric based on the at least one matching instance.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for delivering extended payloads with composite watermarks. Examples disclosed herein embed a first watermark into a media stream in accordance with a first watermark technology, where the first watermark includes a first indicator bit and a first payload. Disclosed examples also embed a second watermark into the media stream in accordance with a second watermark technology, where the second watermark includes a second indicator bit and a second payload. In some disclosed examples, the first indicator bit and the second indicator bit are to indicate whether the first payload and the second payload are to be combined when the first watermark and the second watermark are decoded.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to determine whether audience measurement meters are co-located. An example apparatus is to, based on a difference between a first sampling time of a first entry of a first log and a second sampling time of a corresponding entry of a second log satisfying a first threshold, determine at least one matching instance of at least one first device identifier of the first entry and at least one second device identifier of the corresponding entry. Additionally, the example apparatus is to populate a variable with the at least one matching instance. The example apparatus is also to, based on a metric satisfying a second threshold, cause transmission of an alert indicating that a first meter and a second meter were co-located during generation of the first log and the second log, the metric based on the at least one matching instance.

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 and apparatus are disclosed for supplementing partially readable and/or inaccurate codes. An example apparatus includes a watermark analyzer to select a first watermark and a second watermark decoded from media; a comparator to compare a first decoded timestamp of the first watermark to a second decoded timestamp of the second watermark; and a timestamp adjuster to adjust the second decoded timestamp based on the first decoded timestamp of the second watermark when at least a threshold number of symbols of the second decoded timestamp match corresponding symbols of the first decoded timestamp.