Speech coding

About: Speech coding is a research topic. Over the lifetime, 14245 publications have been published within this topic receiving 271964 citations.

System and method for concealing errors in an audio transmission

Abstract: A system and method of the present invention conceal errors caused by lost audio in an audio transmission. A frame error detector detects audio data lost in an audio data transmission. An audio decoder generates frequency and time domain data from received audio data. A transient detector detects the presence of a transient audio signal in the received audio data. A frame synthesizer interpolates frequency domain data to generate synthetic audio data to construct audio data in place of the lost audio data.

Variable rate vector quantization for speech, image, and video compression

Abstract: The performance of a vector quantizer can be improved by using a variable-rate code. Three variable-rate vector quantization systems are applied to speech, image, and video sources and compared to standard vector quantization and noiseless variable-rate coding approaches. The systems range from a simple and flexible tree-based vector quantizer to a high-performance, but complex, jointly optimized vector quantizer and noiseless code. The systems provide significant performance improvements for subband speech coding, predictive image coding, and motion-compensated video, but provide only marginal improvements for vector quantization of linear predictive coefficients in speech and direct vector quantization of images. Criteria are suggested for determining when variable-rate vector quantization may provide significant performance improvement over standard approaches. >

Generalized analysis-by-synthesis coding and its application to pitch prediction

Abstract: Many modifications can be applied to a speech signal without changing its perceptual quality. For a particular speech coder, the coding efficiency will differ for distinct modifications. To exploit this, the authors introduced a generalized analysis-by-synthesis procedure. In this procedure, a search is performed over a multitude of modified original signals (on a blockwise basis), and the signal which can be encoded with the least distortion is selected for transmission. At the receiver, a quantized version of this modified original signal is constructed. The authors discuss the application of generalized analysis-by-synthesis coding to the pitch predictor of a code excited linear predictor (CELP) coder. The use of this technique makes it possible to transmit the pitch predictor parameters at a much lower rate than conventional approaches, without compromising speech quality. >

System and method for concealment of data loss in digital audio transmission

Abstract: A system and method for the concealment of errors resulting from missing or corrupted data in the transmission of audio signals in compressed digital packet formats is disclosed. The system utilizes a circular FIFO buffer to store audio frames from the transmitted audio signal, and a beat detector, to identify the presence of beats in the audio signal. The error concealment method replaces erroneous audio frames with error-free audio frames by a process which takes into account the presence and location of the detected beats.

Speech and Audio Coding for Wireless and Network Applications

Abstract: I: Introduction. II: Low Delay Speech Coding. III: Speech Quality. IV: Speech Coding for Wireless Transmission. V: Audio Coding. VI: Speech Coding for Noisy Transmission Channels. VII: Topics in Speech Coding. Author Index. Index.