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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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Proceedings ArticleDOI
20 Nov 2014
TL;DR: The proposed error-mapping scheme is derived by observing statistical properties of the error signal and improves coding efficiency as well as computational complexity of the coder.
Abstract: In scalable audio coders, such as the MPEG-4 SLS, error-mapping is used to map quantization errors in the core coder to an error signal before passing through bit-plane coding. In this paper, we propose a new error-mapping scheme that is derived by observing statistical properties of the error signal. Compared with the error-mapping in SLS, the proposed scheme improves coding efficiency as well as computational complexity of the coder. An average improvement of 9 points in MUSHRA score has been achieved by the proposed scheme in subjective listening tests. The proposed error-mapping adds a useful new tool to the existing toolset for constructing next-generation scalable audio coders.
Proceedings ArticleDOI
20 Sep 1995
TL;DR: The proposed MultiPulse coder makes use of a spiky deconvolution algorithm to obtain the sparse exO, and has the low computational complexity and the flexibility to operate at a wide range of bit rates, by simply selecting the suitable pulse rate.
Abstract: The wideband speech coder proposed in this paper is based on a MultiPulse scheme developed in our Department [l] in 1992. The MP coder is a full-band scheme which makes forward linear prediction analysis every frame of 16 ms. The bit rate for this coder is able to swatch, every 2 msec, between five possible rates from 16 kbps to 33 kbps. The quality measures show a lower objective quality for the MP coder when wmparing with the standard but a similar subjective quality. 1 Wideband Speech Coding Wideband speech coding (50-7000 Hz) is required for the emerging high-quality communications. The channel capacity of these new teleservices allows to spend more than 16 kbps for the speech codec without the bandwith restriction of the conventional telephony. The reference coder for the wideband speech signals is the ITU-T standard G.722, a two-bands ADPCM coder with three possible bit rates, 64 kbps, 56 kbps and 48 kbps [2]. The current activities are concentrated on coding at 32 kbps without decreasing the quality of the standard at 64 kbps and with the goal of wideband speech coding at 16 kbps [3]. Few schemes for wideband speech coding have been proposed until now, most of them based on the CELP algorithm [4, 51. The main drawbacks of a traditional CELP, working with wideband speech, are the huge computational complexity and the memory requirements to store the codebooks. Our proposed MultiPulse coder makes use of a spiky deconvolution algorithm to obtain the sparse exOThis work has been partially funded by Northern Telecom and by the Spanish Research National Plan under grant no. TIC92-0800-C05-02. citation. The main characteristics of this coder are the low computational complexity and the flexibility to operate at a wide range of bit rates, by simply selecting the suitable pulse rate. For telephonic speech, we get a Variable Rate version with six different operating rates from 9.1 kbps to 4.8 kbps, offering a high to toll speech quality [6, 71.
Patent
12 Jul 2005
TL;DR: In this article, techniques and tools for scalable video coding and decoding are described for 3D sub-band video encoder and decoder, where the base layer codec provides efficient compression at low bit rates and produces a base layer compressed video bit stream compatible with existing decoders.
Abstract: Techniques and tools are described for scalable video coding and decoding. For example, a 3D sub-band video encoder includes an embedded base layer codec as well as temporal sub-band transforms and spatial sub-band transforms. The placement of the base layer codec among the sub-band transforms and the role of the base layer codec in scalable video coding vary depending on implementation. In general, the base layer codec provides efficient compression at low bit rates and produces a base layer compressed video bit stream compatible with existing decoders. At the same time, the 3D sub-band video encoder provides spatial and temporal scalability options at higher bit rates, refining the base layer video. A corresponding 3D sub-band video decoder includes an embedded base layer decoder.
Proceedings ArticleDOI
01 Oct 2010
TL;DR: Simulation results indicate that the proposed scheme can improve the SI and the whole performance of WZ video codec in the wavelet domain compared to the existed schemes.
Abstract: The side information (SI) generation is a key function in the Wyner-Ziv (WZ) video coding, which plays an important role in determining the performance of the codec. This paper proposes an improved SI generation scheme for wavelet transform based WZ video codec. In specific, we adopt the motion estimation with Kalman filter, by which an optimal estimation of motion vector can be achieved. Simulation results indicate that the proposed scheme can improve the SI and the whole performance of WZ video codec in the wavelet domain compared to the existed schemes.

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