Embedded coding using a mixed speech and audio coding paradigm

Ramprashad, Sean A.

doi:10.1007/bf02108650

Cited by 8 publications

(3 citation statements)

References 14 publications

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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%

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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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Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 97%

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

et al. 2010

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“…The embedded wideband codec described in this paper utilizes the sub-band structure. Since audible artifacts appear in high-band signals using only the CELP technique due to aliasing distortion [8]- [10], to date highband coding has employed mainly transform-based methods [11]- [13]. However, audible artifacts may sometimes appear due to frequency distortion, especially at lower bit rates.…”

Section: Introductionmentioning

confidence: 99%

Bandwidth Scalable Wideband Codec Using Hybrid Matching Pursuit Harmonic/CELP Scheme

Jeong

Kim

et al. 2009

2009 International Conference on Complex, Intelligent and Software Intensive Systems

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A novel hybrid harmonic/CELP scheme for bandwidth scalable wideband codec is proposed that utilizes a bandsplit technique, where the low-band (0-4 kHz) is critically subsampled and coded using 11.8 kbps G.729E. The highband signal is divided into stationary mode (SM) and nonstationary mode (NSM) components based on its unique characteristics. In the SM portion, the high-band signal is compressed using a multi-stage coding combined sinusoidal model based on the matching pursuit (MP) algorithm and CELP with the circular codebook. In the NSM portion, the high-band signals are coded by CELP with both pulse and circular codebooks. 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. In an informal listening test, the subjective speech quality was rated as comparable to that obtainable with 48 kbps G. 722 and 12.85 kbps G.722.2.

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Perceptual Bit-Patterns based on Partial-Order Allocation Schemes with Application to Subband Speech and Audio Coding

Ramprashad

Bae

2007

2007 Conference Record of the Forty-First Asilomar Conference on Signals, Systems and Computers

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Embedded coding using a mixed speech and audio coding paradigm

Cited by 8 publications

References 14 publications

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

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

Bandwidth Scalable Wideband Codec Using Hybrid Matching Pursuit Harmonic/CELP Scheme

Perceptual Bit-Patterns based on Partial-Order Allocation Schemes with Application to Subband Speech and Audio Coding

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