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Audio Fingerprinting
An acoustic fingerprint is a condensed digital summary, a digital fingerprint, deterministically generated from an audio signal, that can be used to identify an audio sample or quickly locate similar items in a music database. Practical uses of acoustic fingerprinting include identifying songs, melodies, tunes, or advertisements; sound effect library management; and video file identification. Media identification using acoustic fingerprints can be used to monitor the use of specific musical works and performances on radio broadcast, records, CDs, streaming media, and peer-to-peer networks. This identification has been used in copyright compliance, licensing, and other monetization schemes. Attributes A robust acoustic fingerprint algorithm must take into account the perceptual characteristics of the audio. If two files sound alike to the human ear, their acoustic fingerprints should match, even if their binary representations are quite different. Acoustic fingerpr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fingerprint (computing)
In computer science, a fingerprinting algorithm is a procedure that maps an arbitrarily large data item (remove, as a computer file) to a much shorter bit string, its ''fingerprint'', that uniquely identifies the original data for all practical purposes just as human fingerprints uniquely identify people for practical purposes. This fingerprint may be used for data deduplication purposes. This is also referred to as ''file fingerprinting'', ''data fingerprinting'', or ''structured data fingerprinting''. Fingerprints are typically used to avoid the comparison and transmission of bulky data. For instance, a remove, web browser or proxy server can efficiently check whether a remote, by fetching only its fingerprint and comparing it with that of the previously fetched copy. Fingerprint functions may be seen as high-performance hash functions used to uniquely identify substantial blocks of data where cryptographic functions may be. Special algorithms exist for audio and video fingerpr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zero Crossing
A zero-crossing is a point where the sign of a mathematical function changes (e.g. from positive to negative), represented by an intercept of the axis (zero value) in the graph of the function. It is a commonly used term in electronics, mathematics, acoustics, and image processing. In electronics In alternating current, the zero-crossing is the instantaneous point at which there is no voltage present. In a sine wave or other simple waveform, this normally occurs twice during each cycle. It is a device for detecting the point where the voltage crosses zero in either direction. The zero-crossing is important for systems that send digital data over AC circuits, such as modems, X10 home automation control systems, and Digital Command Control type systems for Lionel and other AC model trains. Counting zero-crossings is also a method used in speech processing to estimate the fundamental frequency of speech. In a system where an amplifier with digitally controlled gain is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hash Collision
In computer science, a hash collision or hash clash is when two distinct pieces of data in a hash table share the same hash value. The hash value in this case is derived from a hash function which takes a data input and returns a fixed length of bits. Although hash algorithms, especially cryptographic hash algorithms, have been created with the intent of being Collision resistance, collision resistant, they can still sometimes map different data to the same hash (by virtue of the pigeonhole principle). Malicious users can take advantage of this to mimic, access, or alter data. Due to the possible negative applications of hash collisions in data management and computer security (in particular, cryptographic hash functions), collision avoidance has become an important topic in computer security. Background Hash collisions can be unavoidable depending on the number of objects in a set and whether or not the bit string they are mapped to is long enough in length. When there is a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hash Table
In computer science, a hash table is a data structure that implements an associative array, also called a dictionary or simply map; an associative array is an abstract data type that maps Unique key, keys to Value (computer science), values. A hash table uses a hash function to compute an ''index'', also called a ''hash code'', into an array of ''buckets'' or ''slots'', from which the desired value can be found. During lookup, the key is hashed and the resulting hash indicates where the corresponding value is stored. A map implemented by a hash table is called a hash map. Most hash table designs employ an Perfect hash function, imperfect hash function. Hash collision, Hash collisions, where the hash function generates the same index for more than one key, therefore typically must be accommodated in some way. In a well-dimensioned hash table, the average time complexity for each lookup is independent of the number of elements stored in the table. Many hash table designs also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Background Noise
Background noise or ambient noise is any sound other than the sound being monitored (primary sound). Background noise is a form of noise pollution or interference. Background noise is an important concept in setting noise levels. Background noises include environmental noises such as water waves, traffic noise, alarms, extraneous speech, bioacoustic noise from animals, and electrical noise from devices such as refrigerators, air conditioning, power supplies, and motors. The prevention or reduction of background noise is important in the field of active noise control. It is an important consideration with the use of ultrasound (e.g. for medical diagnosis or imaging), sonar, and sound reproduction. Other uses In astronomy, background noise or cosmic background radiation is electromagnetic radiation from the sky with no discernible source. In information architecture, irrelevant, duplicate or incorrect information may be called background noise. In physics and telecommun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shazam (music App)
Shazam is an application that can identify music based on a short sample played using the microphone on the device. It was created by the British company Shazam Entertainment, based in London, and has been owned by Apple since 2018. The software is available for Android, macOS, iOS, Wear OS, watchOS and as a Google Chrome extension. The original UK developer of the app, Shazam Entertainment Limited, was founded in 1999 by Chris Barton, Philip Inghelbrecht, Avery Wang, and Dhiraj Mukherjee. On 24 September 2018, the company was acquired by Apple for a reported $400 million. Overview Shazam identifies songs using an audio fingerprint based on a time-frequency graph called a spectrogram. It uses a smartphone or computer's built-in microphone to gather a brief sample of the audio being played. Shazam stores a catalogue of audio fingerprints in a database. The user records a song for 10 seconds and the application creates an audio fingerprint. Shazam works by analyzing the cap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectrogram
A spectrogram is a visual representation of the spectrum of frequencies of a signal as it varies with time. When applied to an audio signal, spectrograms are sometimes called sonographs, voiceprints, or voicegrams. When the data are represented in a 3D plot they may be called '' waterfall displays''. Spectrograms are used extensively in the fields of music, linguistics, sonar, radar, speech processing, seismology, ornithology, and others. Spectrograms of audio can be used to identify spoken words phonetically, and to analyse the various calls of animals. A spectrogram can be generated by an optical spectrometer, a bank of band-pass filters, by Fourier transform or by a wavelet transform (in which case it is also known as a scaleogram or scalogram). A spectrogram is usually depicted as a heat map, i.e., as an image with the intensity shown by varying the colour or brightness. Format A common format is a graph with two geometric dimensions: one axis represents time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Search By Sound
Search by sound is the retrieval of information based on audio input. There are a handful of applications, specifically for mobile devices that utilize search by sound. Shazam, Soundhound, Axwave, ACRCloud and others have seen considerable success by using a simple algorithm to match an acoustic fingerprint to a song in a library. These applications take a sample clip of a song, or a user-generated melody and check a music library/ music database to see where the clip matches with the song. From there, song information will be queried and displayed to the user. These kinds of applications are mainly used for finding a song that the user does not already know. Searching by sound is not limited to just identifying songs, but also for identifying melodies, tunes or advertisements, sound library management and video files. Acoustic fingerprinting The way these apps search by sound is through generating an acoustic fingerprint; a digital summary of the sound. A microphone is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Transmission
In telecommunications, transmission (sometimes abbreviated as "TX") is the process of sending or propagating an analog or digital signal via a medium that is wired, wireless, or fiber-optic. Transmission system technologies typically refer to physical layer protocol duties such as modulation, demodulation, line coding, equalization, error control, bit synchronization and multiplexing, but it may also involve higher-layer protocol duties, for example, digitizing an analog signal, and data compression. Transmission of a digital message, or of a digitized analog signal, is known as data transmission. Examples of transmission are the sending of signals with limited duration, for example, a block or packet of data, a phone call, or an email. See also *Radio transmitter In electronics and telecommunications, a radio transmitter or just transmitter (often abbreviated as XMTR or TX in technical documents) is an electronic device which produces radio waves with an ante ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Data Compression
In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression reduces bits by identifying and eliminating Redundancy (information theory), statistical redundancy. No information is lost in lossless compression. Lossy compression reduces bits by removing unnecessary or less important information. Typically, a device that performs data compression is referred to as an encoder, and one that performs the reversal of the process (decompression) as a decoder. The process of reducing the size of a data file is often referred to as data compression. In the context of data transmission, it is called source coding: encoding is done at the source of the data before it is stored or transmitted. Source coding should not be confused with channel coding, for error detection and correction or line coding, the means ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bandwidth (signal Processing)
Bandwidth is the difference between the upper and lower Frequency, frequencies in a continuous Frequency band, band of frequencies. It is typically measured in unit of measurement, unit of hertz (symbol Hz). It may refer more specifically to two subcategories: ''Passband bandwidth'' is the difference between the upper and lower cutoff frequencies of, for example, a band-pass filter, a communication channel, or a signal spectrum. ''Baseband bandwidth'' is equal to the upper cutoff frequency of a low-pass filter or baseband signal, which includes a zero frequency. Bandwidth in hertz is a central concept in many fields, including electronics, information theory, digital communications, radio communications, signal processing, and spectroscopy and is one of the determinants of the capacity of a given communication channel. A key characteristic of bandwidth is that any band of a given width can carry the same amount of information, regardless of where that band is located in the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Band
Spectral bands are regions of a given spectrum, having a specific range of wavelengths or frequencies. Most often, it refers to electromagnetic bands, regions of the electromagnetic spectrum. More generally, spectral bands may also be means in the spectra of other types of signals, e.g., noise spectrum. A frequency band is an interval in the frequency domain, limited by a lower frequency and an upper frequency. For example, it may refer to a '' radio band'', such as wireless communication standards set by the International Telecommunication Union. In nuclear physics In nuclear physics, spectral bands refer to the electromagnetic emission of polyatomic systems, including condensed materials, large molecules, etc. Each '' spectral line'' corresponds to the difference in two energy levels of an atom. In molecules, these levels can split. When the number of atoms is large, one gets a continuum of energy levels, the so-called ''spectral bands''. They are often labeled in the sam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
