Baudline
Encyclopedia
The baudline time-frequency
browser is a signal analysis tool designed for scientific visualization
. It runs on several Unix
operating systems under the X Window System. Baudline is useful for real-time
spectral monitoring, collected signals analysis, generating test signals, making distortion
measurements, and playing back audio files.
Time-frequency representation
A time–frequency representation is a view of a signal represented over both time and frequency. Time–frequency analysis means analysis into the time–frequency domain provided by a TFR...
browser is a signal analysis tool designed for scientific visualization
Scientific visualization
Scientific visualization is an interdisciplinary branch of science according to Friendly "primarily concerned with the visualization of three-dimensional phenomena , where the emphasis is on realistic renderings of volumes, surfaces, illumination sources, and so forth, perhaps...
. It runs on several Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
operating systems under the X Window System. Baudline is useful for real-time
Real-time computing
In computer science, real-time computing , or reactive computing, is the study of hardware and software systems that are subject to a "real-time constraint"— e.g. operational deadlines from event to system response. Real-time programs must guarantee response within strict time constraints...
spectral monitoring, collected signals analysis, generating test signals, making distortion
Distortion
A distortion is the alteration of the original shape of an object, image, sound, waveform or other form of information or representation. Distortion is usually unwanted, and often many methods are employed to minimize it in practice...
measurements, and playing back audio files.
Applications
- Acoustic cryptanalysisAcoustic cryptanalysisAcoustic cryptanalysis is a side channel attack which exploits sounds emitted by computers or machines. Modern acoustic cryptanalysis mostly focuses on sounds emitted by computer keyboards and internal computer components, but historically it has also been applied to impact printers and...
- Audio codecAudio codecAll codecs are devices or computer programs capable of coding or decoding a digital data stream or signal.The term audio codec has two meanings depending on the context:...
lossy compression analysis - Audio signal processingAudio signal processingAudio signal processing, sometimes referred to as audio processing, is the intentional alteration of auditory signals, or sound. As audio signals may be electronically represented in either digital or analog format, signal processing may occur in either domain...
- BioacousticsBioacousticsBioacoustics is a cross-disciplinary science that combines biology and acoustics. Usually it refers to the investigation of sound production, dispersion through elastic media, and reception in animals, including humans. This involves neurophysiological and anatomical basis of sound production and...
research - Data acquisitionData acquisitionData acquisition is the process of sampling signals that measure real world physical conditions and converting the resulting samples into digital numeric values that can be manipulated by a computer. Data acquisition systems typically convert analog waveforms into digital values for processing...
(DAQ) - InfrasoundInfrasoundInfrasound is sound that is lower in frequency than 20 Hz or cycles per second, the "normal" limit of human hearing. Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high...
monitoring - Musical acousticsMusical acousticsMusical acoustics or music acoustics is the branch of acoustics concerned with researching and describing the physics of music – how sounds employed as music work...
- Seismic data processingSeismologySeismology is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other planet-like bodies. The field also includes studies of earthquake effects, such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, oceanic,...
- SETISETIThe search for extraterrestrial intelligence is the collective name for a number of activities people undertake to search for intelligent extraterrestrial life. Some of the most well known projects are run by the SETI Institute. SETI projects use scientific methods to search for intelligent life...
- Signal analysis
- Software Defined Radio
- Spectral analysisSpectral analysisSpectral analysis or Spectrum analysis may refer to:* Spectrum analysis in chemistry and physics, a method of analyzing the chemical properties of matter from bands in their visible spectrum...
- Very low frequencyVery low frequency225px|thumb|right|A VLF receiving antenna at [[Palmer Station]], Antarctica, operated by Stanford UniversityVery low frequency or VLF refers to radio frequencies in the range of 3 kHz to 30 kHz. Since there is not much bandwidth in this band of the radio spectrum, only the very simplest signals...
(VLF) reception - WWV frequency measurement
Features
- Spectrogram, SpectrumFrequency spectrumThe frequency spectrum of a time-domain signal is a representation of that signal in the frequency domain. The frequency spectrum can be generated via a Fourier transform of the signal, and the resulting values are usually presented as amplitude and phase, both plotted versus frequency.Any signal...
, Waveform, and Histogram displays - FourierFast Fourier transformA fast Fourier transform is an efficient algorithm to compute the discrete Fourier transform and its inverse. "The FFT has been called the most important numerical algorithm of our lifetime ." There are many distinct FFT algorithms involving a wide range of mathematics, from simple...
, CorrelationCross-correlationIn signal processing, cross-correlation is a measure of similarity of two waveforms as a function of a time-lag applied to one of them. This is also known as a sliding dot product or sliding inner-product. It is commonly used for searching a long-duration signal for a shorter, known feature...
, and RasterRaster graphicsIn computer graphics, a raster graphics image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a monitor, paper, or other display medium...
transforms - SNRSignal-to-noise ratioSignal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. It is defined as the ratio of signal power to the noise power. A ratio higher than 1:1 indicates more signal than noise...
, THDTotal harmonic distortionThe total harmonic distortion, or THD, of a signal is a measurement of the harmonic distortion present and is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency...
, SINADSINADSINAD stands for Signal-to-noise and distortion ratio. It is a measure of the quality of a signal from a communications device, often defined as:...
, ENOB, SFDR distortion measurements - Channel equalizationEqualizationEqualization, is the process of adjusting the balance between frequency components within an electronic signal. The most well known use of equalization is in sound recording and reproduction but there are many other applications in electronics and telecommunications. The circuit or equipment used...
- Function generatorFunction generatorA function generator is a piece of electronic test equipment or software used to generate different types of electrical waveforms over a wide range of frequencies. These waveforms can be either repetitive or single-shot, in which case some kind of triggering source is required...
- Digital down converterDownsamplingIn signal processing, downsampling is the process of reducing the sampling rate of a signal. This is usually done to reduce the data rate or the size of the data....
- Audio playing with real-time DSP effects like speed controlSample rate conversionSample rate conversion is the process of converting a signal from one sampling rate to another, while changing the information carried by the signal as little as possible...
, pitch scaling, frequency shiftingTuner (radio)A radio tuner is a subsystem that receives radio broadcasts and converts them into audio-frequency signals which can be fed into an amplifier driving a loudspeaker. FM tuner, AM tuner, Digital Audio Broadcasting DAB tuner, etc. are types of radio tuner dealing with transmissions using different...
, matrix surroundSurround soundSurround sound encompasses a range of techniques such as for enriching the sound reproduction quality of an audio source with audio channels reproduced via additional, discrete speakers. Surround sound is characterized by a listener location or sweet spot where the audio effects work best, and...
panning, filtering, and digital gain boost - Audio recording of multiple channels
- JACK Audio Connection KitJACK Audio Connection KitJACK is a professional sound server daemon that provides real-time, low latency connections for both audio and MIDI data between applications that implement its API...
sound server support - Import AIFFAIFFAudio Interchange File Format is an audio file format standard used for storing sound data for personal computers and other electronic audio devices...
, AUAu file formatThe Au file format is a simple audio file format introduced by Sun Microsystems. The format was common on NeXT systems and on early Web pages. Originally it was headerless, being simply 8-bit µ-law-encoded data at an 8000 Hz sample rate. Hardware from other vendors often used sample rates as...
, WAVWAVWaveform Audio File Format , is a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs...
, FLACFLACFLAC is a codec which allows digital audio to be losslessly compressed such that file size is reduced without any information being lost...
, MP3MP3MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression...
, OggOggOgg is a free, open container format maintained by the Xiph.Org Foundation. The creators of the Ogg format state that it is unrestricted by software patents and is designed to provide for efficient streaming and manipulation of high quality digital multimedia.The Ogg container format can multiplex...
VorbisVorbisVorbis is a free software / open source project headed by the Xiph.Org Foundation . The project produces an audio format specification and software implementation for lossy audio compression...
, AVIAudio Video InterleaveAudio Video Interleave , known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback...
, MOV, and other file formatFile formatA file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
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See also
- Linux audio software
- List of information graphics software
- List of numerical analysis software
- Digital signal processingDigital signal processingDigital signal processing is concerned with the representation of discrete time signals by a sequence of numbers or symbols and the processing of these signals. Digital signal processing and analog signal processing are subfields of signal processing...