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公开(公告)号：EP1147514B1
公开(公告)日：2005-04-06
申请号：EP00975894.7
申请日：2000-10-19
CPC分类号： G10L19/0208
摘要： In an audio transmission system, an input signal is split up into two spectral portions in a transmitter. These spectral portions are coded by their own respective coder. The low-frequency signal portion is coded by a regular narrow-band coder and the high frequency portion is coded using a coder that outputs LPC codes and signal amplitude codes. In the receiver, the low frequency signal portion is reconstructed by a narrow-band decoder and the high frequency portion is reconstructed by applying a high pass filter to a white noise signal and applying an LPC filter that is controlled by the LPC codes to this filtered white noise signal and adjusting the signal amplitude with an amplifier that is controlled using the amplitude codes of the transmitter. The reconstructed low frequency signal and the reconstructed high frequency signal are then combined to yield a reconstructed output signal containing both frequency ranges.
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公开(公告)号：EP1147514A1
公开(公告)日：2001-10-24
申请号：EP00975894.7
申请日：2000-10-19
IPC分类号： G10L19/02
CPC分类号： G10L19/0208
摘要： In an audio transmission system, an input signal is split up into two spectral portions in a transmitter. These spectral portions are coded by their own respective coder. The low-frequency signal portion is coded by a regular narrow-band coder and the high frequency portion is coded using a coder that outputs LPC codes and signal amplitude codes. In the receiver, the low frequency signal portion is reconstructed by a narrow-band decoder and the high frequency portion is reconstructed by applying a high pass filter to a white noise signal and applying an LPC filter that is controlled by the LPC codes to this filtered white noise signal and adjusting the signal amplitude with an amplifier that is controlled using the amplitude codes of the transmitter. The reconstructed low frequency signal and the reconstructed high frequency signal are then combined to yield a reconstructed output signal containing both frequency ranges.
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公开(公告)号：EP1905009B1
公开(公告)日：2009-09-16
申请号：EP06766032.4
申请日：2006-07-06
IPC分类号： G10L19/08
CPC分类号： G10L13/033 , G10L19/093 , G10L2021/0135
摘要： A device (2) for changing the pitch of an audio signal (r), such as a speech signal, comprises a sinusoidal analysis unit (21) for determining sinusoidal parameters of the audio signal (r), a parameter production unit (22) for predicting the phase of a sinusoidal component, and a sinusoidal synthesis unit (23) for synthesizing the parameters to produce a reconstructed signal (r'). The parameter production unit (22) receives, for each time segment of the audio signal, the phase of the previous time segment to predict the phase of the current time segment.
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公开(公告)号：EP1905009A1
公开(公告)日：2008-04-02
申请号：EP06766032.4
申请日：2006-07-06
IPC分类号： G10L19/08
CPC分类号： G10L13/033 , G10L19/093 , G10L2021/0135
摘要： A device (2) for changing the pitch of an audio signal (r), such as a speech signal, comprises a sinusoidal analysis unit (21) for determining sinusoidal parameters of the audio signal (r), a parameter production unit (22) for predicting the phase of a sinusoidal component, and a sinusoidal synthesis unit (23) for synthesizing the parameters to produce a reconstructed signal (r'). The parameter production unit (22) receives, for each time segment of the audio signal, the phase of the previous time segment to predict the phase of the current time segment.
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公开(公告)号：EP0998741A2
公开(公告)日：2000-05-10
申请号：EP99919469.9
申请日：1999-05-20
IPC分类号： G10L19/00
摘要： In a speech transmission system, an input speech signal is applied to a speech encoder (12, 36) for encoding the input speech signal. The encoded speech signal is transmitted via a communication channel (10) to a speech decoder (30, 48). In order to improve the performance of the transmission system in the presence of background noise, it is proposed to introduce background noise dependent processing elements in the speech encoder (12, 36) and/or in the speech decoder (30, 48). In a first embodiment of the invention, the parameters of the perceptual weighting filter (124) in the speech encoder (12, 36) are derived by calculating linear prediction coefficients (â) from a speech signal which is processed by means of a high-pass filter (82). In a second embodiment of the invention, an adaptive post filter (150) in a speech decoder (30, 48) is by-passed when the noise level exceeds a threshold value.
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公开(公告)号：EP1609335A2
公开(公告)日：2005-12-28
申请号：EP04721612.2
申请日：2004-03-18
IPC分类号： H04S1/00
CPC分类号： G10L19/008 , H04S1/007 , H04S2420/03
摘要： The multichannel signal is represented by the main signal and a set transformation parameters which represent the side signal. It enables reducing the bit rate of the transmitted signal without degrading the quality of the multichannel signal.
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公开(公告)号：EP1099215B1
公开(公告)日：2005-02-23
申请号：EP00931174.7
申请日：2000-05-08
IPC分类号： G10L19/08
CPC分类号： G10L19/02 , G10L2025/906
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8.发明公开METHOD OF TRANSMISSION OF WIDEBAND AUDIO SIGNALS ON A TRANSMISSION CHANNEL WITH REDUCED BANDWIDTH 有权宽带信号的传输方法在具有减小的带宽的传输信道
公开(公告)号：EP1446797A1
公开(公告)日：2004-08-18
申请号：EP02775085.0
申请日：2002-10-10
IPC分类号： G10L21/02
CPC分类号： G10L19/018 , G10L21/038
摘要： A narrow-band audio signal (9) contains information, present as recognisable distortions, for processing the signal into a wide-band signal. In a method for processing a wide-band audio signal (1) into a narrow-band signal (9), a first spectral portion (4) is maintained unchanged in the narrow-band signal and information (7) usable for restoring remaining spectral portions (5) is embedded (8), preferably perceptually inaudible, by distorting said first spectral portion in a recognisable way, and preferably as a watermark. An encoder for coding a wide-band audio signal (1) into a narrow-band signal (9) and a decoder for decoding a narrow-band audio signal are disclosed, as well as a system for transmitting a wide-band audio signal through a narrow-band transmission channel, a system for storing a wide-band audio signal on a storage medium and retrieving the wide-band signal from storage, and a storage medium carrying a narrow-band audio signal.
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公开(公告)号：EP1099215A1
公开(公告)日：2001-05-16
申请号：EP00931174.7
申请日：2000-05-08
IPC分类号： G10L19/08
CPC分类号： G10L19/02 , G10L2025/906
摘要： In several types of audio coding a frequency of one or more periodical components is determined and used in the encoding process. The frequency of the periodical component to be determined is not always constant, but may slightly vary over an analysis interval. To correct for said frequency change, the system according to the invention comprises frequency change determining means (8) which determine a change of the frequency of the periodical component over the analysis period. This change of frequency can be transmitted to the decoder for increasing the accuracy of the reconstruction of the audio signal. Also it is possible that the frequency change is only used to obtain a more accurate value of the pitch. Preferably the frequency change is determined by using a time warper (6) which performs a time transformation such that a time transformed audio signal is obtained with a minimum frequency change.
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公开(公告)号：EP1522063B1
公开(公告)日：2007-03-07
申请号：EP03735915.5
申请日：2003-06-18
IPC分类号： G10L19/02
CPC分类号： G10L19/093
摘要： Coding (1) an audio signal (x) comprises providing a respective set of sampled signal values for each of a plurality of sequential segments. The sampled signal values are analysed (130) to generate one or more sinusoidal components for each of the plurality of sequential segments. The sinusoidal components are linked across a plurality of sequential segments. Sinusoidal codes (CS) comprise tracks of linked sinusoidal components for each of the plurality of sequential segments. Each track comprises a frequency and amplitude for a sinusoidal component in a starting segment of a track whereas selected tracks include an indicator that no phase is included for said starting segment.
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