Methods, apparatus, systems, and articles of manufacture are disclosed to monitor on-demand media. An example apparatus populates a reference library with a reference profile for on-demand media in response to publication of the on-demand media by generating one or more reference signatures for the on-demand media, collecting reference metadata associated with the on-demand media, and associating the one or more reference signatures and the reference metadata in the reference library to generate the reference profile. Additionally, the example apparatus collects one or more sample signatures generated at a media presentation environment. The example apparatus also records an exposure for the on-demand media based on a match between the one or more sample signatures and the one or more reference signatures.

Automated data-matching includes obtaining first and second stored fingerprints generated from first and second data. The stored fingerprints are divided into frames, and grouped into first blocks and second blocks including an equal number of frames. Each frame included in a current first block is compared to each frame included in a current second block to determine a number of matching frames, and a hamming distance between the current first block and the current second block is determined, based at least in part on the number of matching frames. A determination is made, based at least in part on the hamming distance, whether the current first block and the current second block match.

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.

A computing system compares various reference fingerprints each representing a reference media stream broadcast on a different respective known channel, and the computing system determines that a plurality of the reference fingerprints match each other, thus defining a multi-match group of the matching reference fingerprints. In response, the computing system identifies a fingerprint feature that could define a distinction between the reference fingerprints, and the computing system resolves the multi-match based on the identified feature, thereby determining the channel carrying the media stream being rendered by the media presentation device. And the computing system could then take channel-specific action based on the determined channel.

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.

Example local devices disclosed herein include memory including a set of reference fingerprints corresponding to media, the set of reference fingerprints from a remote device different from the local device and one or more processor circuits to execute machine readable instructions to generate a monitored fingerprint of the media presented at a location and compare the monitored fingerprint to at least some of the set of reference fingerprints from the remote device. Additionally, the one or more processor circuits are to determine an amount of time that has passed since the media started and after a match between the monitored fingerprint and one or more reference fingerprints of the set of reference fingerprints, cause transmission of audience measurement information to identify the media, the audience measurement information including data indicative of the amount of time that has passed since the media started.

Example apparatus disclosed herein are to obtain a first hash key, a second hash key and a third hash key representative of first reference media in response to a first query of a first table, the second hash key associated with a second time preceding a first time associated with the first hash key, the third hash key associated with a third time following the first time associated with the first hash key. Disclosed example apparatus are also to prequalify the first hash key as a candidate for subsequent signature processing associated with a first site signature in response to a determination that the second hash key corresponds to a second site signature preceding the first site signature in time and that the third hash key corresponds to a third site signature following the first site signature in time.

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.

A boundary specifying a bounded geographic area for which travel information is to be reported is generated. Flow section information associated with flow sections located within the boundary is obtained. The flow sections represent portions of one or more roadways assigned relevant functional road classes (FRCs). The flow section information includes information about traffic flow associated with the flow sections. FRC current traffic messages, which include non-predictive traffic information associated with roadway portions that are in the bounded geographic area and are assigned relevant FRCs, are combined with the flow section information to generate a first data group. The first data group is streamed to a first traffic message service.

Real-time latency of audio/video streams is identified. Signatures of a reference audio/video stream and signatures of a test audio/video stream are buffered. A needle is constructed as a vector including a set of signatures of the reference audio/video stream. Correlations of the needle to successive vectors of sets of signatures of the test audio/video stream are computed using a correlation function that calculates relatedness of the needle vector to each of the successive vectors of the test audio/video stream. A synchronization offset is identified between the test stream and the reference stream according to a maximum correlation point of the correlations of the needle to the successive sets of signatures of the test audio/video stream. The reference audio/video stream and the test audio/video stream are aligned according to the synchronization offset.