A method of encoding an input speech signal using a multi-rate encoder having a plurality of encoding rates is disclosed. A high-pass filter and then a perceptual weighting filter are applied to such signal to generate a first target signal. An adaptive codebook vector is identified from an adaptive codebook using the first target signal by filtering the vector to generate a filtered adaptive codebook vector. An adaptive codebook gain for the adaptive codebook vector is calculated and an error signal minimized. The adaptive codebook gain is adaptively reduced based on one encoding rate from the plurality of encoding rates to generate a reduced adaptive codebook gain. A second target signal based at least on the first target signal and the reduced adaptive codebook gain is generated. The input speech signal is converted into an encoded speech based on the second target signal.

Speech codec employing speech classification for noise compensation

An encoding method and apparatus and a decoding method and apparatus in which the encoded information is decreased in volume and in which the encoding and decoding operations are performed with a smaller processing volume and a smaller buffer memory capacity. The apparatus includes a low range signal splitting circuit for separating low-range side signal components from L and R channel signals converted by a transform circuit into spectral signal components, and a channel synthesis circuit for synthesizing (L+R) channel signal components from the L and R channel spectral signal components. The apparatus also includes a high range signal separating circuit for separating the high range side signal components from the (L+R) channel signal components, a signal component encoding circuit for compression-encoding low-range side signal components and a signal component encoding circuit for compression-encoding the normalization coefficient information obtained on normalization of the (L+R) channel high-range signal components.

Encoding method and apparatus, decoding method and apparatus and recording medium

An information encoding method for encrypting and encoding information signals, such as PCM audio signals, in which the information signals can be reproduced with low quality even in the absence of the key information for encryption For carrying out the information encoding method, the input PCM signals are converted by a transform unit into frequency signal components which are encoded by a signal component encoding unit High frequency range side signal components are sent to an Ex-OR gate to take an Ex-OR of the high frequency range side signal components with a pseudo random bitstring from a pseudo random bitstring generating unit A codestring generating unit 1606 generates a codestring having the low frequency range side components from a signal component encoding unit and the encrypted high frequency range side components from the Ex-OR gate

Methods and apparatus for encoding, decoding, encrypting and decrypting an audio signal, recording medium therefor, and method of transmitting an encoded encrypted audio signal

The invention provides a data processing apparatus and method which processes data in which additional data is embedded and inhibits illegal accessing from the outside to prevent alteration of information The data processing apparatus includes a coding section for coding the data, a detection section for detecting the additional data from the data, a processing section for processing the coded data coded by the coding section, and a control section for controlling operation of the processing section in response to the additional data detected by the detection section The coding section controls an output thereof in response to the additional data detected by the detection section, and accessing to the additional data used to control the coding section is inhibited

Data processing apparatus, coding apparatus, data processing method and coding method

The present invention provides a method and a system with which information embedded in compressed digital audio data can be directly operated. An embodiment of the system for embedding additional information in compressed audio data includes: means for extracting MDCT (Modified Discrete Cosine Transform) coefficients from the compressed audio data; means for employing the MDCT coefficients to calculate a frequency component for the compressed audio data; means for embedding additional information in the frequency component obtained in a frequency domain; means for transforming into MDCT coefficients the frequency component in which the additional information is embedded; and means for using the MDCT coefficients, in which the additional information is embedded, to generate compressed audio data.

Electronic watermarking method and apparatus for compressed audio data, and system therefor

The present invention includes an encoding and decoding apparatus and method where there is used a transform processing to allow a waveform element of a corresponding block to interfere with waveform elements of blocks adjoining in both directions at the time of inverse transform processing as in the case of, e.g., MDCT, to compose a waveform signal, amplifying processing in encoding and corresponding correction processing in decoding can be carried out without inconsistency between blocks. Thus, occurrence of pre-echo can be prevented by simple configuration by using spectrum transform processing of high encoding efficiency.

Information encoding method and apparatus, information decoding method and apparatus, information recording medium, and information transmission method

Kyoya Tsutsui

Papers

Information encoding method and apparatus, information decoding method and apparatus, information recording medium, and information transmission method

Information coding/decoding method and apparatus, information recording medium and information transmission method