Methods, apparatus, systems and articles of manufacture are disclosed selectively generating and storing hashed reference signatures. An example method disclosed herein determining whether watermark coverage of a first media segment satisfies a dropout constraint, the first media segment corresponding to a first monitoring time interval of a media source feed and, when the watermark coverage of the first media segment does not satisfy the dropout constraint hashing first media signatures associated with the first media segment to generate corresponding first hashed signatures and generating first reference data for the first media segment, the first reference data including the first hashed signatures and the first media signatures. The example method further includes, when the watermark coverage of the first media segment satisfies the dropout constraint, generating second reference data for the first media segment, the second reference data including the first media signatures.

Methods, apparatus, systems and articles of manufacture are disclosed selectively generating and storing hashed reference signatures. An example method disclosed herein determining whether watermark coverage of a first media segment satisfies a dropout constraint, the first media segment corresponding to a first monitoring time interval of a media source feed and, when the watermark coverage of the first media segment does not satisfy the dropout constraint hashing first media signatures associated with the first media segment to generate corresponding first hashed signatures and generating first reference data for the first media segment, the first reference data including the first hashed signatures and the first media signatures. The example method further includes, when the watermark coverage of the first media segment satisfies the dropout constraint, generating second reference data for the first media segment, the second reference data including the first media signatures.

Methods, apparatus, and systems are disclosed for synchronizing streaming media content. An example apparatus includes a storage device, and a processor to execute instructions to identify a first source streaming broadcast media to a first computing device based on an audio fingerprint of audio associated with the broadcast media, identify sources broadcasting the broadcast media streaming to the first computing device, the sources available to a second computing device including the processor, select a second source of the identified sources for streaming the broadcast media to the second computing device, the second source different than the first source, detect termination of the streaming of the broadcast media on the first computing device, the termination corresponding to a termination time of the broadcast media, and automatically start, by using the selected second source, streaming of the broadcast media to the second computing device at the termination time.

Methods, apparatus, and systems are disclosed for synchronizing streaming media content. An example apparatus includes a storage device, and a processor to execute instructions to identify a first source streaming broadcast media to a first computing device based on an audio fingerprint of audio associated with the broadcast media, identify sources broadcasting the broadcast media streaming to the first computing device, the sources available to a second computing device including the processor, select a second source of the identified sources for streaming the broadcast media to the second computing device, the second source different than the first source, detect termination of the streaming of the broadcast media on the first computing device, the termination corresponding to a termination time of the broadcast media, and automatically start, by using the selected second source, streaming of the broadcast media to the second computing device at the termination time.

Methods, apparatus, and machine-readable storage media to monitor media presentations are disclosed. A disclosed example apparatus includes a locator to compare a location of a mobile device with a set of reference locations at which audio monitoring is to be performed. The disclosed example apparatus further includes an audio receiver to enable a microphone of the mobile device to collect audio for media monitoring when (1) the location of the mobile device corresponds to a first one of the reference locations and (2) a media presentation monitor at the first one of the reference locations indicates a likelihood of media being presented at the first location satisfies a threshold. In some disclosed examples, the audio receiver of the example apparatus is to disable the microphone from collecting audio for media monitoring when the location of the mobile device does not correspond to any of the reference locations.

Methods, apparatus, and machine-readable storage media to monitor media presentations are disclosed. A disclosed example apparatus includes a locator to compare a location of a mobile device with a set of reference locations at which audio monitoring is to be performed. The disclosed example apparatus further includes an audio receiver to enable a microphone of the mobile device to collect audio for media monitoring when (1) the location of the mobile device corresponds to a first one of the reference locations and (2) a media presentation monitor at the first one of the reference locations indicates a likelihood of media being presented at the first location satisfies a threshold. In some disclosed examples, the audio receiver of the example apparatus is to disable the microphone from collecting audio for media monitoring when the location of the mobile device does not correspond to any of the reference locations.

Methods, apparatus, systems and articles of manufacture are disclosed to monitor a split screen media presentation. Example apparatus includes means for processing audio output from a media device to determine audio metering data to identify first media presented by the media device, means for generating one or more video signatures associated with video output from the media device, and means for identifying a first region-of-interest of a split screen presentation of the media device including the first media, the means for identifying to identify the first region-of-interest in response to a determination that the one or more generated video signatures do not match reference video signatures corresponding to the first media.

Methods, apparatus, systems and articles of manufacture are disclosed to monitor a split screen media presentation. Example apparatus includes means for processing audio output from a media device to determine audio metering data to identify first media presented by the media device, means for generating one or more video signatures associated with video output from the media device, and means for identifying a first region-of-interest of a split screen presentation of the media device including the first media, the means for identifying to identify the first region-of-interest in response to a determination that the one or more generated video signatures do not match reference video signatures corresponding to the first media.

Methods, apparatus, systems and articles of manufacture are disclosed for source classification using HDMI audio metadata. An example apparatus includes a metadata extractor to extract values of audio encoding parameters from HDMI metadata obtained from a monitored HDMI port of a media device, the HDMI metadata corresponding to media being output from the monitored HDMI port; map the extracted values of the audio encoding parameters to a first unique encoding class (UEC) in a set of defined UECs, different ones of the set of defined UECs corresponding to different combinations of possible values of the audio encoding parameters capable of being included in the HDMI metadata; and identify a media source corresponding to the media output from the HDMI port based on one or more possible media sources mapped to the first UEC.

A person can use a portable electronic device to electronically purchase or otherwise request a product, service or other deliverable related to audio programming to which the person is listening at the time they initiate the request. The request is fulfilled by a service that analyzes the audio content to identify the deliverable the person desires.