High quality MELP coding at bit-rates around 4 kb/s

Stachurski, Jacek; McCree, Alan; Viswanathan, V.

doi:10.1109/icassp.1999.758168

Cited by 10 publications

(2 citation statements)

References 5 publications

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“…The performance of MELP at 2.4 kbps is similar to or better than that of the federal standard at 4.8 kbps (FS 1016) [92]. Versions of MELP coders operating at 1.7 kbps [68] and 4.0 kbps [90] have been reported.…”

Section: Mixed-excitation Linear Prediction (Melp)mentioning

confidence: 85%

Speech Coding: Fundamentals and Applications

Hasegawa‐Johnson

Alwan

2003

Wiley Encyclopedia of Telecommunications

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In this chapter, we present an overview of the most widely used algorithms, standards, and applications of wideband and narrowband speech coding. Algorithms for speech coding are classified into four broad headings: (1) waveform coding techniques (including PCM, companded PCM, and DPCM), which are typically used for landline telephony, internet telephony, and secure military communications; (2) subband coding, including perceptually transparent multi‐rate and embedded coding which is mainly used for internet and digital audio applications; (3) linear predictive analysis by synthesis coding (LPC‐AS) algorithms, including multipulse LPC, CELP, SELP, VSELP, and low‐delay CELP, which are typically used for digital cellular and telephony; and (4) LPC vocoders, including advanced vocoder algorithms (e.g., MELP, MBE, and PWI) are used for applications such as secure telephony and satellite telephony. Applications in areas such as voiceover IP (VoIP) and digital cellular are emerging and require a speech coder to gracefully adapt to rapidly changing channel conditions—a need that is met by embedded and multirate speech coders associated with joint source‐channel coding algorithms. Measures of speech coder perceptual quality include subjective measures of intelligibility (DRT and DALT) and naturalness (MOS and DAM), as well as objective measures such as segmental SNR, Bark spectral distortion, PSQM, and PESQ. Speech coding standards are set by organizations including the ITU (for landline telephony), MPEG (for multimedia applications), ETSI (for European digital cellular), TIA (for U.S. digital cellular), and DDVPC (for United States military applications).

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Section: Mixed-excitation Linear Prediction (Melp)mentioning

confidence: 85%

Speech Coding: Fundamentals and Applications

Hasegawa‐Johnson

Alwan

2003

Wiley Encyclopedia of Telecommunications

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“…One possible way to deal with the vectors of varying dimension is to provide separate codebooks for different dimensions; for instance, one codebook per dimension is an effective solution at the expense of elevated storage cost. In [22] an MELP coder operating near 4 kbps is described where the harmonic magnitudes are quantized using a switched predictive MSVQ having four codebooks. Two codebooks are used for magnitude vectors of dimension less than 55, and the other two for magnitude vectors of dimension greater than 45; the ranges overlap so that some spectra are included in both groups.…”

Section: Multi-codebookmentioning

confidence: 99%

Vector Quantization of Harmonic Magnitudes in Speech Coding Applications—A Survey and New Technique

Chu¹

2004

EURASIP J. Adv. Signal Process.

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A harmonic coder extracts the harmonic components of a signal and represents them efficiently using a few parameters. The principles of harmonic coding have become quite successful and several standardized speech and audio coders are based on it. One of the key issues in harmonic coder design is in the quantization of harmonic magnitudes, where many propositions have appeared in the literature. The objective of this paper is to provide a survey of the various techniques that have appeared in the literature for vector quantization of harmonic magnitudes, with emphasis on those adopted by the major speech coding standards; these include constant magnitude approximation, partial quantization, dimension conversion, and variable-dimension vector quantization (VDVQ). In addition, a refined VDVQ technique is proposed where experimental data are provided to demonstrate its effectiveness.

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Low-Bit-Rate Speech Coding

McCree

2008

Springer Handbook of Speech Processing

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High quality MELP coding at bit-rates around 4 kb/s

Cited by 10 publications

References 5 publications

Speech Coding: Fundamentals and Applications

Speech Coding: Fundamentals and Applications

Vector Quantization of Harmonic Magnitudes in Speech Coding Applications—A Survey and New Technique

Low-Bit-Rate Speech Coding

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