The original paper is in English. Non-English content has been machine-translated and may contain typographical errors or mistranslations. ex. Some numerals are expressed as "XNUMX".
Copyrights notice
The original paper is in English. Non-English content has been machine-translated and may contain typographical errors or mistranslations. Copyrights notice
Em 1995, o codificador CS-ACELP de 8 kb/s do G.729 foi padronizado pelo ITU-T SG15 e foi relatado que a qualidade de fala do G.729 é melhor ou igual à do ADPCM de 32 kb/s (G .726). Contudo, o G.729 é o codificador de voz de taxa fixa e não considera a propriedade da atividade de voz na conversação mútua. Se usarmos a atividade de voz, podemos reduzir a taxa média de bits pela metade sem qualquer degradação da qualidade da fala. Neste artigo, propomos um algoritmo eficiente de taxa variável para G.729. O algoritmo de taxa variável consiste em dois assuntos principais, o algoritmo de determinação de taxa e o projeto de codificadores de subtaxa. Para o algoritmo VAD robusto, combinamos o método de limite de energia, o método de segmentação fonética pela integração de vários parâmetros de características obtidos através do procedimento de análise e o método do período de ressaca variável. Através da análise de características de ruído, o codificador de subtaxa de 1 kb/s é projetado para codificar o sinal de ruído de fundo. Além disso, projetamos o codificador de subtaxa de 4 kb/s para as partes não sonoras. O desempenho do algoritmo de taxa variável é avaliado pela comparação da qualidade da fala e da taxa média de bits com o G.729. O teste de qualidade subjetiva também é feito pelo teste MOS. Conclusivamente, verifica-se que o codificador CS-ACELP de taxa variável proposto produz a mesma qualidade de voz do G.729, à taxa média de bits de 4.4 kb/s.
The copyright of the original papers published on this site belongs to IEICE. Unauthorized use of the original or translated papers is prohibited. See IEICE Provisions on Copyright for details.
Copiar
Woosung CHUNG, Sangwon KANG, "Design of a Variable Rate Algorithm for the CS-ACELP Coder" in IEICE TRANSACTIONS on Information,
vol. E82-D, no. 10, pp. 1364-1371, October 1999, doi: .
Abstract: In 1995, 8 kb/s CS-ACELP coder of G.729 is standardized by ITU-T SG15 and it has been reported that the speech quality of G.729 is better than or equal to that of 32 kb/s ADPCM (G.726). However G.729 is the fixed rate speech coder, and it does not consider the property of voice activity in mutual conversation. If we use the voice activity, we can reduce the average bit rate in half without any degradations of the speech quality. In this paper, we propose an efficient variable rate algorithm for G.729. The variable rate algorithm consists of two main subjects, the rate determination algorithm and the design of sub rate coders. For the robust VAD algorithm, we combine the energy-thresholding method, the phonetic segmentation method by integration of various feature parameters obtained through the analysis procedure, and the variable hangover period method. Through the analysis of noise features, the 1 kb/s sub rate coder is designed for coding the background noise signal. Also, we design the 4 kb/s sub rate coder for the unvoiced parts. The performance of the variable rate algorithm is evaluated by the comparison of speech quality and average bit rate with G.729. Subjective quality test is also done by MOS test. Conclusively, it is verified that the proposed variable rate CS-ACELP coder produces the same speech quality as G.729, at the average bit rate of 4.4 kb/s.
URL: https://global.ieice.org/en_transactions/information/10.1587/e82-d_10_1364/_p
Copiar
@ARTICLE{e82-d_10_1364,
author={Woosung CHUNG, Sangwon KANG, },
journal={IEICE TRANSACTIONS on Information},
title={Design of a Variable Rate Algorithm for the CS-ACELP Coder},
year={1999},
volume={E82-D},
number={10},
pages={1364-1371},
abstract={In 1995, 8 kb/s CS-ACELP coder of G.729 is standardized by ITU-T SG15 and it has been reported that the speech quality of G.729 is better than or equal to that of 32 kb/s ADPCM (G.726). However G.729 is the fixed rate speech coder, and it does not consider the property of voice activity in mutual conversation. If we use the voice activity, we can reduce the average bit rate in half without any degradations of the speech quality. In this paper, we propose an efficient variable rate algorithm for G.729. The variable rate algorithm consists of two main subjects, the rate determination algorithm and the design of sub rate coders. For the robust VAD algorithm, we combine the energy-thresholding method, the phonetic segmentation method by integration of various feature parameters obtained through the analysis procedure, and the variable hangover period method. Through the analysis of noise features, the 1 kb/s sub rate coder is designed for coding the background noise signal. Also, we design the 4 kb/s sub rate coder for the unvoiced parts. The performance of the variable rate algorithm is evaluated by the comparison of speech quality and average bit rate with G.729. Subjective quality test is also done by MOS test. Conclusively, it is verified that the proposed variable rate CS-ACELP coder produces the same speech quality as G.729, at the average bit rate of 4.4 kb/s.},
keywords={},
doi={},
ISSN={},
month={October},}
Copiar
TY - JOUR
TI - Design of a Variable Rate Algorithm for the CS-ACELP Coder
T2 - IEICE TRANSACTIONS on Information
SP - 1364
EP - 1371
AU - Woosung CHUNG
AU - Sangwon KANG
PY - 1999
DO -
JO - IEICE TRANSACTIONS on Information
SN -
VL - E82-D
IS - 10
JA - IEICE TRANSACTIONS on Information
Y1 - October 1999
AB - In 1995, 8 kb/s CS-ACELP coder of G.729 is standardized by ITU-T SG15 and it has been reported that the speech quality of G.729 is better than or equal to that of 32 kb/s ADPCM (G.726). However G.729 is the fixed rate speech coder, and it does not consider the property of voice activity in mutual conversation. If we use the voice activity, we can reduce the average bit rate in half without any degradations of the speech quality. In this paper, we propose an efficient variable rate algorithm for G.729. The variable rate algorithm consists of two main subjects, the rate determination algorithm and the design of sub rate coders. For the robust VAD algorithm, we combine the energy-thresholding method, the phonetic segmentation method by integration of various feature parameters obtained through the analysis procedure, and the variable hangover period method. Through the analysis of noise features, the 1 kb/s sub rate coder is designed for coding the background noise signal. Also, we design the 4 kb/s sub rate coder for the unvoiced parts. The performance of the variable rate algorithm is evaluated by the comparison of speech quality and average bit rate with G.729. Subjective quality test is also done by MOS test. Conclusively, it is verified that the proposed variable rate CS-ACELP coder produces the same speech quality as G.729, at the average bit rate of 4.4 kb/s.
ER -