A scalable speech and audio coding scheme with continuous bitrate flexibility

Kovesi, B.; Massaloux, D.; Sollaud, A.

doi:10.1109/icassp.2004.1325975

Cited by 11 publications

(5 citation statements)

References 3 publications

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“…The scalable codec uses an efficient frame erasure concealment algorithm [18] that can correct the effect of missing frames even in severe packet loss conditions. A more detailed description of the codec can be found in [19]. Coming back to the scalability issue, which is of interest for us in this paper, one of the main advantages of this codec is its high granularity.…”

Section: Scalable Audio Codingmentioning

confidence: 98%

A Context-Aware Network Equipment for Dynamic Adaptation of Multimedia Services in Wireless Networks

Mathieu

2007

Wireless Pers Commun

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B3G (Beyond 3rd Generation) networks is the next step in the wireless world. It will enable the delivery of services to end-users, on different underlying wireless access networks and customised to users' context. Furthermore, seamless mobility between networks and switch of devices will be handled in a transparent way. In this paper, a Context-Aware Network Equipment (CANE) is introduced, that is able to dynamically adapt multimedia services according to the users' context. The term context includes the users' device, the users' preferences, the network conditions as well as the service provider adaptation policies. As a proof of concept, an implementation of a CANE is given for a 802.11 network use-case. An evaluation of the prototype as well as simulations of the proposed solution, both for an audio streaming service and a video streaming service, are presented. The results show that adapting multimedia services in case of network overload can enable to maintain an acceptable quality of service delivered to end-users and even to allow more users to enjoy the services, which will not be possible without the CANE.

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Section: Scalable Audio Codingmentioning

confidence: 98%

A Context-Aware Network Equipment for Dynamic Adaptation of Multimedia Services in Wireless Networks

Mathieu

2007

Wireless Pers Commun

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“…The enhancement layers in the proposed scheme employ a hybrid harmonic/CELP scheme for highband coding. Since audible artifacts appear in high-band signals using only the CELP technique due to aliasing distortion (Kataoka et al 1989;Javovo et al 1997;Jung et al 2004), at present high-band coding generally employs transform-based methods (Ramprashad 1999;Kovesi et al 2004;You et al 2005). However, audible artifacts may sometimes appear due to frequency distortion, especially at lower bit rates.…”

Section: Introductionmentioning

confidence: 96%

“…Efforts to construct a wideband speech codec with an embedded structure based on applying a standard narrowband codec to a base core can be divided into two main approaches, according to the way the target signal is fed into the enhancement layer. In the first, the enhancement layer encodes the coding error in the base layer (Ramprashad 1998;Koishida et al 2000;Kim et al 2002;Dong and Gibson 2006), while in the second the previously split high-band signals are encoded (Kataoka et al 1989;Javovo et al 1997;Jung et al 2004;Ramprashad 1999;Kovesi et al 2004;You et al 2005). Scalability with the latter type of improvement is referred to as bandwidth scalable codec or sub-band codec.…”

Section: Introductionmentioning

confidence: 97%

Embedded bandwidth scalable wideband codec using hybrid matching pursuit harmonic/CELP scheme

et al. 2010

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Recent advances in speech coding have made wideband coding feasible at the bit-rates sufficient for mobile communication. Here we propose a novel hybrid harmocic Code Excited Linear Prediction (CELP) scheme for highband coding of band-split scalable wideband codec, where the low-band (0-4 kHz) is critically subsampled and coded selectively using existing narrowband codecs such as 5.4 kbps and 6.3 kbps G.723.1, 8 kbps G.729, and 11.8 kbps G.729E. The high-band signal is divided into stationary mode (SM) and non-stationary mode (NSM) components based on its unique characteristics. In the SM portion, the highband signal is compressed using a multi-stage coding that combines the sinusoidal model and CELP. The first stage coding applies the damping factor matching pursuit (MP) algorithm without either the Over-Lap-Add (OLA) or smoothly interpolative synthesis schemes and the second stage utilizes CELP with the circular codebook. In the NSM portion, the high-band signals are coded by CELP with both pulse and circular codebooks by applying the complexity-reduced algorithm. To ensure scalability in highband coding, two enhancement layers are used to increase the number of pulses and control the quantizing sinusoidal parameter numbers. This paper describes the new algorithm and discuses novel techniques for efficient bandwidth wideband speech coding and subjective quality performance. For efficient bit allocation and enhanced performance, the pitch of the high-band codec is estimated using the quantized pitch parameter in low-band codec. An informal listening test, rated the subjective speech quality as comparable to that obtainable with G.722.2 as the fullband wideband codec and G.722.2 as the highband codec, the recent standardized band-split wideband codec.

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“…The MDCT coefficients in each subband are vector quantized, using trained spherical codebooks that are embedded in size and composed of an union of permutation codes. The subbands are transmitted by order of perceptual importance as in [7].…”

Section: Predictive Mdct Coding (Layers Above 14 Kbit/s)mentioning

confidence: 99%

“…It also maps signals into a weighted domain similar to the CELP target domain used at 8 and 12 kbit/s. The MDCT encoder is a variant of the "TDAC coder" described in [6,7]. The difference y(k) = y1(k) − y2(k) is computed in the 0-3.4 Hz band, while the weighted original signal is taken (i.e.…”

Section: Predictive Mdct Coding (Layers Above 14 Kbit/s)mentioning

confidence: 99%

A 8–32 KBIT/S Scalable Wideband Speech and Audio Coding Candidate for ITU-T G729EV Standardization

Ragot

Kovesi

Virette

et al.

2006 IEEE International Conference on Acoustics Speed and Signal Processing Proceedings

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This paper describes a 8-32 kbit/s scalable speech and audio coder submitted as a candidate for the ITU-T G729-based Embedded Variable bitrate (G729EV) standardization. The coder is built upon a 3-stage coding structure consisting of: narrowband cascade CELP coding at 8 and 12 kbit/s, bandwidth extension based on wideband linear-predictive coding (WB-LPC) at 14 kbit/s, and MDCT coding in a WB-LPC weighted signal domain from 14 to 32 kbit/s. ITU-T test results showed that this coder passed all the requirements of the G729EV qualification phase.

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A scalable speech and audio coding scheme with continuous bitrate flexibility

Cited by 11 publications

References 3 publications

A Context-Aware Network Equipment for Dynamic Adaptation of Multimedia Services in Wireless Networks

A Context-Aware Network Equipment for Dynamic Adaptation of Multimedia Services in Wireless Networks

Embedded bandwidth scalable wideband codec using hybrid matching pursuit harmonic/CELP scheme

A 8–32 KBIT/S Scalable Wideband Speech and Audio Coding Candidate for ITU-T G729EV Standardization

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