Abstract: Systems, methods, and non-transitory computer-readable media can store fingerprint data corresponding to one or more content items in an index data structure, the index data structure comprising a set of bins, wherein at least one first bin references a list of fingerprinted frames, and wherein at least one fingerprinted frame in the list corresponds to a first content item. A determination is made that one or more fingerprinted frames corresponding to a second content item are to be added to the index data structure. At least one of the fingerprinted frames corresponding to the second content item are added to the list of fingerprinted frames that is referenced by the first bin.

Abstract: An audio identification system generates a probe audio fingerprint of an audio signal and determines amount of pitch shifting in the audio signal based on analysis of correlation between the probe audio fingerprint and a reference audio fingerprint. The audio identification system applies a time-to-frequency domain transform to frames of the audio signal and filters the transformed frames. The audio identification system applies a two-dimensional discrete cosine transform (DCT) to the filtered frames and generates the probe audio fingerprint from a selected number of DCT coefficients. The audio identification system calculates a DCT sign-only correlation between the probe audio fingerprint and the reference audio fingerprint, and the DCT sign-only correlation closely approximates the similarity between the audio characteristics of the probe audio fingerprint and those of the reference audio fingerprint.

Abstract: Systems, methods, and non-transitory computer-readable media can store fingerprint data corresponding to one or more content items in an index data structure, the index data structure comprising a set of bins, wherein at least one first bin references a list of fingerprinted frames, and wherein at least one fingerprinted frame in the list corresponds to a first content item. A determination is made that one or more fingerprinted frames corresponding to a second content item are to be added to the index data structure. At least one of the fingerprinted frames corresponding to the second content item are added to the list of fingerprinted frames that is referenced by the first bin.

Abstract: Systems, methods, and non-transitory computer-readable media can determine that a publisher is providing a first live content stream for distribution through the social networking system, the first live content stream including copyrighted content. A determination is made that a broadcaster is providing a second live content stream for distribution through the social networking system. The first live content stream and the second live content stream are exposed to at least some users of the social networking system. While the first live content stream and the second live content stream are being distributed through the social networking system, a determination is made that at least some portions of the second live content stream match copyrighted content included in the first live content stream. At least one notification is provided to the broadcaster of the second live content stream, wherein the notification indicates a potential copyright violation by the broadcaster.

Abstract: An audio identification system generates a probe audio fingerprint of an audio signal and determines amount of pitch shifting in the audio signal based on analysis of correlation between the probe audio fingerprint and a reference audio fingerprint. The audio identification system applies a time-to-frequency domain transform to frames of the audio signal and filters the transformed frames. The audio identification system applies a two-dimensional discrete cosine transform (DCT) to the filtered frames and generates the probe audio fingerprint from a selected number of DCT coefficients. The audio identification system calculates a DCT sign-only correlation between the probe audio fingerprint and the reference audio fingerprint, and the DCT sign-only correlation closely approximates the similarity between the audio characteristics of the probe audio fingerprint and those of the reference audio fingerprint.

Abstract: An audio identification system generates a probe audio fingerprint of an audio signal and determines amount of pitch shifting in the audio signal based on analysis of correlation between the probe audio fingerprint and a reference audio fingerprint. The audio identification system applies a time-to-frequency domain transform to frames of the audio signal and filters the transformed frames. The audio identification system applies a two-dimensional discrete cosine transform (DCT) to the filtered frames and generates the probe audio fingerprint from a selected number of DCT coefficients. The audio identification system calculates a DCT sign-only correlation between the probe audio fingerprint and the reference audio fingerprint, and the DCT sign-only correlation closely approximates the similarity between the audio characteristics of the probe audio fingerprint and those of the reference audio fingerprint.

Abstract: An audio identification system generates a probe audio fingerprint of an audio signal and determines amount of pitch shifting in the audio signal based on analysis of correlation between the probe audio fingerprint and a reference audio fingerprint. The audio identification system applies a time-to-frequency domain transform to frames of the audio signal and filters the transformed frames. The audio identification system applies a two-dimensional discrete cosine transform (DCT) to the filtered frames and generates the probe audio fingerprint from a selected number of DCT coefficients. The audio identification system calculates a DCT sign-only correlation between the probe audio fingerprint and the reference audio fingerprint, and the DCT sign-only correlation closely approximates the similarity between the audio characteristics of the probe audio fingerprint and those of the reference audio fingerprint.