Digital audio signal coding using a CELP coder and a transform coder
    1.
    发明授权
    Digital audio signal coding using a CELP coder and a transform coder 失效
    使用CELP编码器和变换编码器的数字音频信号编码

    公开(公告)号:US6134518A

    公开(公告)日:2000-10-17

    申请号:US34931

    申请日:1998-03-04

    摘要: Apparatus is described for digitally encoding an input audio signal for storage or transmission. A distinguishing parameter is measure from the input signal. It is determined from the measured distinguishing parameter whether the input signal contains an audio signal of a first type or a second type. First and second coders are provided for digitally encoding the input signal using first and second coding methods respectively and a switching arrangement directs, at any particular time, the generation of an output signal by encoding the input signal using either the first or second coders according to whether the input signal contains an audio signal of the first type or the second type at that time. A method for adaptively switching between transform audio coder and CELP coder, is presented. In a preferred embodiment, the method makes use of the superior performance of CELP coders for speech signal coding, while enjoying the benefits of transform coder for other audio signals. The combined coder is designed to handle both speech and music and achieve an improved quality.

    摘要翻译: 描述了用于对用于存储或传输的输入音频信号进行数字编码的装置。 一个区别的参数是从输入信号测量。 根据测量的区分参数确定输入信号是否包含第一类型或第二类型的音频信号。 提供了第一和第二编码器,用于分别使用第一和第二编码方法对输入信号进行数字编码,并且切换装置在任何特定时间通过使用根据第一或第二编码器对输入信号进行编码来引导输出信号的产生 此时输入信号是否包含第一类型或第二类型的音频信号。 提出了一种在转换音频编码器和CELP编码器之间进行自适应切换的方法。 在优选实施例中,该方法利用CELP编码器用于语音信号编码的优越性能,同时享受用于其他音频信号的变换编码器的优点。 组合编码器旨在处理语音和音乐,并实现改进的质量。

    Digital audio signal coding
    2.
    发明授权
    Digital audio signal coding 失效
    数字音频信号编码

    公开(公告)号:US6064954A

    公开(公告)日:2000-05-16

    申请号:US34516

    申请日:1998-03-04

    IPC分类号: G10L19/02 G10L19/12

    CPC分类号: G10L19/0212

    摘要: Apparatus is disclosed for digitally encoding an input audio signal, for storage or transmission, comprising: a pitch detector for determining at least a dominant time-domain periodicity in the input signal; a generator for generating a prediction signal based on the dominant time domain periodicity of the input signal; a first discrete frequency domain transform generator for generating a frequency domain representation of the input signal; a second discrete frequency domain transform generator for generating a frequency domain representation of the prediction signal; a subtractor to subtract at least a portion of the frequency domain representation of the prediction signal from the frequency domain representation of the input signal to generate an error signal; and a generator to generate an output signal from the error signal and parameters defining the prediction signal. A corresponding decoder is also described.

    摘要翻译: 公开了用于对用于存储或传输的输入音频信号进行数字编码的装置,包括:用于确定输入信号中的至少主要时域周期性的音调检测器; 用于基于输入信号的主要时域周期来产生预测信号的发生器; 用于产生所述输入信号的频域表示的第一离散频域变换发生器; 第二离散频域变换发生器,用于产生所述预测信号的频域表示; 减法器,用于从输入信号的频域表示中减去预测信号的频域表示的至少一部分,以产生误差信号; 以及发生器,用于从所述误差信号和定义所述预测信号的参数产生输出信号。 还描述了相应的解码器。