Proceedings ArticleDOI
Embedded Wideband Vselp Speech Coding With Optimized Codebooks
A. Le Guyader,E. Boursicaut +1 more
- pp 15-16
TLDR
This contribution derives a new algorithm for the off-line optimization of the basis vectors in the multi-stage VSELP case and shows that codebooks orthogonalization leads to optimum embedded coders for variable bit rates.Abstract:
The need of variable bit rate actually exists for an increasing number of applications such as videoconferencing, audioconferencing and packet circuit multiplication. In this contribution we extend the concept of variable bit rate to multi-stage VSELP coding. First we begin with an unified approach for multi stage CELP and VSELP coding and we show that codebooks orthogonalization leads to optimum embedded coders for variable bit rates. Then we derive a new algorithm for the off-line optimization of the basis vectors in the multi-stage case. Finally we give some subjective test results obtained with 24 and 32 kbitts embedded wideband speech coders.read more
Citations
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Proceedings ArticleDOI
A two stage hybrid embedded speech/audio coding structure
TL;DR: A two stage hybrid embedded speech/audio coding structure uses a speech coder as a core to provide the minimal bitrate and an acceptable performance on speech inputs and a transform coder using a modified discrete cosine transform and perceptual coding principles is proposed.
Proceedings ArticleDOI
A 16-kbit/s bandwidth scalable audio coder based on the G.729 standard
TL;DR: Subjective tests show that the proposed bandwidth-scalable coding scheme based on the G.729 standard as a base layer coder achieves better performance than the 16 kbit/s MPEG-4 CELP with bandwidth scalability.
Proceedings ArticleDOI
High quality embedded wideband speech coding using an inherently layered coding paradigm
TL;DR: The design uses many of the inherently layered features of the original non-embedded MTPC including iterative bit assignments and frequency domain coding, and uses the mode decision of the MTPC to adapt the layering strategy to the type input signal.
Journal ArticleDOI
Embedded coding using a mixed speech and audio coding paradigm
TL;DR: A two stage hybrid embedded speech/audio coding structure and algorithm is proposed which can be used to enhance the quality of an existing codec without modification of the original coding algorithm.
Proceedings ArticleDOI
SNR and bandwidth scalable speech coding
TL;DR: A taxonomy of scalable speech coding structures is presented and an SNR scalable coder for noisy speech is introduced and the use of bandwidth scalable coders for rate switching in wireless environments is proposed.
References
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Proceedings ArticleDOI
Vector sum excited linear prediction (VSELP) speech coding at 8 kbps
I.A. Gerson,M.A. Jasiuk +1 more
TL;DR: The vector sum excited linear prediction speech coder is presented, and it utilizes a codebook with a structure that allows for a very efficient search procedure.
Proceedings ArticleDOI
Pitch-orthogonal code-excited LPC
M. Johnson,Tomohiko Taniguchi +1 more
TL;DR: An algorithm is proposed for the purpose of removing the coding redundancy between the adaptive codebook, or pitch, and the stochastic codebook in a standard CELP speech coder, allowing the calculation of an optimum two-vector gain set using sequential one-vector quantizers.
Proceedings ArticleDOI
Successive orthogonalizations in the multistage CELP coder
TL;DR: The authors investigate three algorithms that orthogonalize codebooks in a multi-stage code excited linear prediction (CELP) speech coder and show that the recursive modified Gram-Schmidt algorithm extra computational cost is less than the other two.