Code-excited linear prediction

About: Code-excited linear prediction is a research topic. Over the lifetime, 2025 publications have been published within this topic receiving 28633 citations. The topic is also known as: CELP.

Improving signal quality of a speech codec using hybrid perceptual-parametric algorithm

Abstract: A hybrid parametric-perceptual speech codec architecture is presented. The basic CELP parametric codec structure is enhanced using the perceptual coding method. The objective of the codec hybridisation is obtaining significant improvement in the perceived signal quality. Two hybrid architectures are proposed. The first one encodes voiced parts perceptually in the CELP residual signal. The second one divides the signal into voiced signal components that are encoded using the perceptual algorithm, unvoiced components that are encoded parametrically and transients remaining unencoded. The signal quality achieved using the hybrid codec is compared to the quality of some standard speech codecs.

Systolizing the covariance analysis of linear predictive coding

Abstract: A systolic array for the covariance analysis of linear predictive coding is developed in this paper. The covariance analysis of linear predictive coding can be computed with a large set of irregular and nested recurrence equations. Systolizing the algorithm is a difficulty task. The task is first decomposed and then mapped onto several interconnected systolic arrays. >

Novel intra prediction algorithm using residual prediction for low power multimedia codecs

Abstract: This paper proposes a novel residual prediction algorithm to improve the coding efficiency It extends the scope of prediction to the residual data The proposed algorithm is adopted for intra prediction which accounts for a major portion of the bit stream The simulation results show that the proposed algorithm can reduce the bit-rate by up to 434% compared with the JM reference software without any degradation of the peak signal to noise ratio By incorporating basic hybrid video coding techniques into the encoder, the proposed residual prediction algorithm can significantly improve the coding efficiency

An apparatus and method for speech condig

Abstract: An apparatus for encoding a voice and a method thereof are provided to have no need to attempt other methods for expanding a narrow band to a wide band or an audio band in a codec having necessity for fine bit rate extension, thereby acquiring algorithm consistency and reducing calculation amount reduction. A band division unit(100) divides an input signal into a high band signal and a low band signal. A narrow band encoding unit(105) encodes the low band signal using a narrow band voice codec based on CELP(Code Excited Linear Prediction). A frequency feature collecting unit(110) converts the high band signal into a frequency domain and calculates MDCT(Modified Discrete Cosine Transform) coefficients. Subband determination units(115,120) determine a subband for shape quantization based on the MDCT coefficients, and determine a subband for gain quantization based on the subband for the determined shape quantization. A gain quantization unit(125) performs gain quantization for the subband for the gain quantization. A bit allocation unit(130) allocates bits to the subband for the gain quantization according to the size of the gain quantization. A shape quantization unit(135) performs shape quantization for the subband for the shape quantization in an algebraical solution.