Proceedings ArticleDOI
Implementation of a low delay modified CELP coder at 4.8 kb/s
Jian Zhang,Hong-Shen Wang,Tian-Hu Yu +2 more
- Vol. 3, pp 1610-1614
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TLDR
Both objective measurement and informal subjective listening tests show that the proposed speech coder has high quality performance.Abstract:
This paper presents a low delay high quality speech coder at low bit rates. The configuration of the speech coder is mainly composed of a formant filter, a pitch codebook, an excitation joint codebook, and post enhancement filters. The algorithm of the speech coder is briefly described. Two versions of the speech coder have been implemented in real-time with a single: ADSP-21020 chip. Both objective measurement and informal subjective listening tests show that the proposed speech coder has high quality performance.read more
Citations
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Patent
Multimode coding of speech-like and non-speech-like signals
TL;DR: In this paper, the authors describe methods and apparatus for code excited linear prediction (CELP) audio encoding and decoding that employ linear predictive coding (LPC) synthesis filters controlled by LPC parameters.
Proceedings ArticleDOI
A fixed-point DSP implementation for a low bit rate vocoder
Fengying Yao,Bizhou Li,Min Zhang +2 more
TL;DR: Fixed-point DSP implementation of the decoder and the synthesizer of a real time vocoder with 1.4 kbps bit rate has been accomplished instead of the usual realization of low bit rate vocoder in floating point DSP to indicate the possibility to implement the whole Vocoder with low cost fixed-pointDSP.
Patent
Multimode coding method and device of speech-like and non-speech-like signals
R·拉达克里希南,俞容山,格兰特·A·戴维森,罗伯特·L·安德森 +3 more
TL;DR: Methods and apparatus for code excited linear prediction (CELP) audio encoding and decoding that employ linear predictive coding (LPC) synthesis filters controlled by LPC parameters, a plurality of codebooks each having codevectors, at least one codebook providing an excitation more appropriate for non-speech-like signals.
References
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Journal ArticleDOI
Least squares quantization in PCM
TL;DR: In this article, the authors derived necessary conditions for any finite number of quanta and associated quantization intervals of an optimum finite quantization scheme to achieve minimum average quantization noise power.
Least Squares Quantization in PCM
TL;DR: The corresponding result for any finite number of quanta is derived; that is, necessary conditions are found that the quanta and associated quantization intervals of an optimum finite quantization scheme must satisfy.
Proceedings ArticleDOI
Improving performance of multi-pulse LPC coders at low bit rates
Sharad Singhal,B. S. Atal +1 more
TL;DR: This paper focuses on problems encountered in attempting to maintain speech quality while synthesizing speech using multi-pulse excitation at lower bit rates.
Proceedings ArticleDOI
Real-time vector APC speech coding at 4800 bps with adaptive postfiltering
Juin-Hwey Chen,Allen Gersho +1 more
TL;DR: An improved Vector APC (VAPC) speech coder at 4800 bps produces speech with very good communications quality while maintaining a complexity low enough to allow a real-time implementation with at most two commercially available DSP chips.
Journal ArticleDOI
An efficient stochastically excited linear predictive algorithm for high quality low bit rate transmission of speech
TL;DR: Improvements to the SELP algorithm are described which result in better speech quality and higher computational efficiency, and a new recursive algorithm which performs a very fast search through the adaptive codebook.