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Residual-excited Linear Prediction
Residual-excited linear prediction (RELP) is an obsolete speech coding algorithm. It was originally proposed in the 1970s and can be seen as an ancestor of code-excited linear prediction (CELP). Unlike CELP however, RELP directly transmits the residual signal. To achieve lower rates, that residual signal is usually down-sampled (e.g. to 1–2 kHz). The algorithm is hardly used anymore in audio transmission. It is still used in some text-to-speech voices, such as the diphone databases found in the Festival A festival is an event ordinarily celebrated by a community and centering on some characteristic aspect or aspects of that community and its religion or cultures. It is often marked as a local or national holiday, mela, or eid. A festival c ... and Flite speech synthesizers. References External links * https://harvest.usask.ca/bitstream/handle/10388/etd-12202003-142739/0105Thesis.pdf?sequence=1&isAllowed=y (5.8 MB) Speech codecs {{tech-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speech Coding
Speech coding is an application of data compression of digital audio signals containing speech. Speech coding uses speech-specific parameter estimation using audio signal processing techniques to model the speech signal, combined with generic data compression algorithms to represent the resulting modeled parameters in a compact bitstream. Some applications of speech coding are mobile telephony and voice over IP (VoIP). The most widely used speech coding technique in mobile telephony is linear predictive coding (LPC), while the most widely used in VoIP applications are the LPC and modified discrete cosine transform (MDCT) techniques. The techniques employed in speech coding are similar to those used in audio data compression and audio coding where knowledge in psychoacoustics is used to transmit only data that is relevant to the human auditory system. For example, in voiceband speech coding, only information in the frequency band 400 to 3500 Hz is transmitted but the reconst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algorithm
In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algorithms are used as specifications for performing calculations and data processing. More advanced algorithms can perform automated deductions (referred to as automated reasoning) and use mathematical and logical tests to divert the code execution through various routes (referred to as automated decision-making). Using human characteristics as descriptors of machines in metaphorical ways was already practiced by Alan Turing with terms such as "memory", "search" and "stimulus". In contrast, a Heuristic (computer science), heuristic is an approach to problem solving that may not be fully specified or may not guarantee correct or optimal results, especially in problem domains where there is no well-defined correct or optimal result. As an effective method, an algorithm ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code-excited Linear Prediction
Code-excited linear prediction (CELP) is a linear predictive speech coding algorithm originally proposed by Manfred R. Schroeder and Bishnu S. Atal in 1985. At the time, it provided significantly better quality than existing low bit-rate algorithms, such as residual-excited linear prediction (RELP) and linear predictive coding (LPC) vocoders (e.g., FS-1015). Along with its variants, such as algebraic CELP, relaxed CELP, low-delay CELP and vector sum excited linear prediction, it is currently the most widely used speech coding algorithm. It is also used in MPEG-4 Audio speech coding. CELP is commonly used as a generic term for a class of algorithms and not for a particular codec. Background The CELP algorithm is based on four main ideas: * Using the source-filter model of speech production through linear prediction (LP) (see the textbook "speech coding algorithm"); * Using an adaptive and a fixed codebook as the input (excitation) of the LP model; * Performing a search in close ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Festival Speech Synthesis System
The Festival Speech Synthesis System is a general multi-lingual speech synthesis system originally developed by Alan W. Black, Paul Taylor and Richard Caley at the Centre for Speech Technology Research (CSTR) at the University of Edinburgh. Substantial contributions have also been provided by Carnegie Mellon University and other sites. It is distributed under a free software license similar to the BSD License. It offers a full text to speech system with various APIs, as well as an environment for development and research of speech synthesis techniques. It is written in C++ with a Scheme-like command interpreter for general customization and extension. Festival is designed to support multiple languages, and comes with support for English (British and American pronunciation), Welsh, and Spanish. Voice packages exist for several other languages, such as Castilian Spanish, Czech, Finnish, Hindi, Italian, Marathi, Polish, Russian and Telugu. Festvox The Festvox project aims to make th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
