36 relations: Algebraic code-excited linear prediction, Ambient noise level, Bit rate, Code-excited linear prediction, Codec, Comfort noise, Comparison of audio coding formats, Conference call, Data compression, Discontinuous transmission, Dual-tone multi-frequency signaling, Fax, Frame (networking), G.711, G.723.1, G.729.1, Internet Assigned Numbers Authority, ITU-T, List of codecs, Mean opinion score, Patent pool, Patent troll, PSQM, Real-time Transport Protocol, Royalty-free, RTP audio video profile, Session Description Protocol, Silence, Silence suppression, Software patent, Speech coding, Variable bitrate, Vocoder, Voice activity detection, Voice over IP, Wideband.
Algebraic code-excited linear prediction (ACELP) is a patented speech coding algorithm by VoiceAge Corporation in which a limited set of pulses is distributed as excitation to a linear prediction filter.
In atmospheric sounding and noise pollution, ambient noise level (sometimes called background noise level, reference sound level, or room noise level) is the background sound pressure level at a given location, normally specified as a reference level to study a new intrusive sound source.
In telecommunications and computing, bit rate (bitrate or as a variable R) is the number of bits that are conveyed or processed per unit of time.
Code-excited linear prediction (CELP) is a speech coding algorithm originally proposed by M. R. Schroeder and B. S. Atal in 1985.
A codec is a device or computer program for encoding or decoding a digital data stream or signal.
Comfort noise (or comfort tone) is synthetic background noise used in radio and wireless communications to fill the artificial silence in a transmission resulting from voice activity detection or from the audio clarity of modern digital lines.
The following tables compare general and technical information for a variety of audio coding formats.
A conference call is a telephone call in which someone talks to several people at the same time.
In signal processing, data compression, source coding, or bit-rate reduction involves encoding information using fewer bits than the original representation.
Discontinuous transmission (DTX) is a means by which a mobile telephone is temporarily shut off or muted while the phone lacks a voice input.
Dual-tone multi-frequency signaling (DTMF) is an in-band telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers.
Fax (short for facsimile), sometimes called telecopying or telefax (the latter short for telefacsimile), is the telephonic transmission of scanned printed material (both text and images), normally to a telephone number connected to a printer or other output device.
A frame is a digital data transmission unit in computer networking and telecommunication.
G.711 is an ITU-T standard for audio companding.
G.723.1 is an audio codec for voice that compresses voice audio in 30 ms frames.
G.729.1 is an 8-32 kbit/s embedded speech and audio codec providing bitstream interoperability with G.729, G.729 Annex A and G.729 Annex B. Its official name is G.729-based embedded variable bit rate codec: An 8-32 kbit/s scalable wideband coder bitstream interoperable with G.729.
The Internet Assigned Numbers Authority (IANA) is a function of ICANN, a nonprofit private American corporation that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System (DNS), media types, and other Internet Protocol-related symbols and Internet numbers.
The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU); it coordinates standards for telecommunications.
The following is a list of compression formats and related codecs.
Mean opinion score (MOS) is a measure used in the domain of Quality of Experience and telecommunications engineering, representing overall quality of a stimulus or system.
In patent law, a patent pool is a consortium of at least two companies agreeing to cross-license patents relating to a particular technology.
In international law and business, patent trolling or patent hoarding is a categorical or pejorative term applied to a person or company that attempts to enforce patent rights against accused infringers far beyond the patent's actual value or contribution to the prior art, often through hardball legal tactics (frivolous litigation, vexatious litigation, strategic lawsuit against public participation (SLAPP), chilling effects, and the like).
PSQM (Perceptual Speech Quality Measure) is a computational and modeling algorithm defined in ITU Recommendation ITU-T P.861 that objectively evaluates and quantifies voice quality of voice-band (300 – 3400 Hz) speech codecs.
The Real-time Transport Protocol (RTP) is a network protocol for delivering audio and video over IP networks.
Royalty-free, or RF, refers to the right to use copyright material or intellectual property without the need to pay royalties or license fees for each use, per each copy or volume sold or some time period of use or sales.
The RTP audio/video profile (RTP/AVP) is a profile for Real-time Transport Protocol (RTP) that specifies the technical parameters of audio and video streams.
The Session Description Protocol (SDP) is a format for describing streaming media communications parameters.
Silence is the lack of audible sound, or the presence of sounds of very low intensity.
The term silence suppression is used in telephony to describe the process of not transmitting information over the network when one of the parties involved in a telephone call is not speaking, thereby reducing bandwidth usage.
A software patent is a patent on a piece of software, such as a computer program, libraries, user interface, or algorithm.
Speech coding is an application of data compression of digital audio signals containing speech.
Variable bitrate (VBR) is a term used in telecommunications and computing that relates to the bitrate used in sound or video encoding.
A vocoder (a portmanteau of voice encoder) is a category of voice codec that analyzes and synthesizes the human voice signal for audio data compression, multiplexing, voice encryption, voice transformation, etc.
Voice activity detection (VAD), also known as speech activity detection or speech detection, is a technique used in speech processing in which the presence or absence of human speech is detected.
Voice over Internet Protocol (also voice over IP, VoIP or IP telephony) is a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet.
In communications, a system is wideband when the message bandwidth significantly exceeds the coherence bandwidth of the channel.