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Adaptive Multi-Rate audio codec

About: Adaptive Multi-Rate audio codec is a research topic. Over the lifetime, 1467 publications have been published within this topic receiving 19736 citations. The topic is also known as: AMR & Adaptive Multi-Rate.


Papers
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13 Nov 2014
TL;DR: The proposed adaptive estimation of detector parameters is proposed to improve detector performance and overcome voice non-stationarity and achieves acceptable robustness against the lossy compression attack by different compression rates of Adaptive Multi Rate (AMR) voice codec.
Abstract: This paper considers the problem of covert communication through dedicated voice channels by embedding secure data in the cover speech signal utilizing spread spectrum additive data hiding. The cover speech signal is modeled by a Generalized Gaussian (GGD) random variable and the Maximum A Posteriori (MAP) detector for extraction of the covert message is designed and its reliable performance is verified both analytically and by simulations. The idea of adaptive estimation of detector parameters is proposed to improve detector performance and overcome voice nonstationarity. The detector's bit error rate (BER) is investigated for both blind and semi-blind cases in which the GGD shape parameter needed for optimum detection is either estimated from the stego or cover signal respectively. The simulation results also show that the proposed method achieves acceptable robustness against the lossy compression attack by different compression rates of Adaptive Multi Rate (AMR) voice codec.

1 citations

Proceedings ArticleDOI
13 May 2002
TL;DR: A new context-based error recovery technique for the CELP-based speech codec accomplishing recovery of erased frames, updating decoder state during erasure spells and reliable estimation of codec parameters in case of bit errors is proposed.
Abstract: GSM AMR speech codec being used for both Internet and mobile networks, robustness to both frame erasures and random bit errors assumes significance. This paper proposes a new context-based error recovery technique for the CELP-based speech codec accomplishing recovery of erased frames, updating decoder state during erasure spells and reliable estimation of codec parameters in case of bit errors. Previous error concealment techniques do not adequately make use of the context in which concealment is being done. The proposed error concealment technique is intended to retrieve and use contextual information for better performance. The method is solely receiver based, uses no look ahead, makes use of implicitly available codec parameters and buffers for parameter estimation and is hence computationally efficient. Segmental Itakura-Saito measure and MOS scores are used to compare the output speech quality of the proposed technique with those of the basic techniques as recommended by the standard.

1 citations

Proceedings ArticleDOI
09 Jul 2009
TL;DR: The method of how to implement a G.729 codec filter on mediastreamer2 is presented and the experimental results show that the implementation of G.711a, speex and gsm codec filter is successful on the whole.
Abstract: Currently, the mediastreamer2 contains internal support for G.711u, G.711a, speex and gsm. However, it does not contain internal support for the popular G.729, which is known as the best audio codec ever. In this paper, we present the method of how to implement a G.729 codec filter on mediastreamer2. Then, we evaluate the performance of the G.729 filter in our platform. The experimental results show that our implementation of G.729 codec on mediastreamer2 is successful on the whole.

1 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202310
202214
20201
20193
20183
201721