Abstract: A linear prediction coefficient of a signal represented in a frequency domain is obtained by performing linear prediction analysis in a frequency direction by using a covariance method or an autocorrelation method. After the filter strength of the obtained linear prediction coefficient is adjusted, filtering may be performed in the frequency direction on the signal by using the adjusted coefficient, whereby the temporal envelope of the signal is shaped. This reduces the occurrence of pre-echo and post-echo and improves the subjective quality of the decoded signal, without significantly increasing the bit rate in a bandwidth extension technique in the frequency domain represented by SBR.

Abstract: A linear prediction coefficient of a signal represented in a frequency domain is obtained by performing linear prediction analysis in a frequency direction by using a covariance method or an autocorrelation method. After the filter strength of the obtained linear prediction coefficient is adjusted, filtering may be performed in the frequency direction on the signal by using the adjusted coefficient, whereby the temporal envelope of the signal is shaped. This reduces the occurrence of pre-echo and post-echo and improves the subjective quality of the decoded signal, without significantly increasing the bit rate in a bandwidth extension technique in the frequency domain represented by SBR.

Abstract: A linear prediction coefficient of a signal represented in a frequency domain is obtained by performing linear prediction analysis in a frequency direction by using a covariance method or an autocorrelation method. After the filter strength of the obtained linear prediction coefficient is adjusted, filtering may be performed in the frequency direction on the signal by using the adjusted coefficient, whereby the temporal envelope of the signal is shaped. This reduces the occurrence of pre-echo and post-echo and improves the subjective quality of the decoded signal, without significantly increasing the bit rate in a bandwidth extension technique in the frequency domain represented by SBR.

Abstract: When a frame immediately preceding an encoding target frame to be encoded by a first encoding unit operating under a linear predictive coding scheme is encoded by a second encoding unit operating under a coding scheme different from the linear predictive coding scheme, the encoding target frame can be encoded under the linear predictive coding scheme by initializing the internal state of the first encoding unit. Therefore, encoding processing performed under a plurality of coding schemes including the linear predictive coding scheme and a coding scheme different from the linear predictive coding scheme can be realized.

Abstract: A linear prediction coefficient of a signal represented in a frequency domain is obtained by performing linear prediction analysis in a frequency direction by using a covariance method or an autocorrelation method. After the filter strength of the obtained linear prediction coefficient is adjusted, filtering may be performed in the frequency direction on the signal by using the adjusted coefficient, whereby the temporal envelope of the signal is transformed. This reduces the occurrence of pre-echo and post-echo and improves the subjective quality of the decoded signal, without significantly increasing the bit rate in a band extension technique in the frequency domain represented by SBR.

Abstract: A linear prediction coefficient of a signal represented in a frequency domain is obtained by performing linear prediction analysis in a frequency direction by using a covariance method or an autocorrelation method. After the filter strength of the obtained linear prediction coefficient is adjusted, filtering may be performed in the frequency direction on the signal by using the adjusted coefficient, whereby the temporal envelope of the signal is shaped. This reduces the occurrence of pre-echo and post-echo and improves the subjective quality of the decoded signal, without significantly increasing the bit rate in a bandwidth extension technique in the frequency domain represented by SBR.

Abstract: When a frame immediately preceding an encoding target frame to be encoded by a first encoding unit operating under a linear predictive coding scheme is encoded by a second encoding unit operating under a coding scheme different from the linear predictive coding scheme, the encoding target frame can be encoded under the linear predictive coding scheme by initializing the internal state of the first encoding unit. Therefore, encoding processing performed under a plurality of coding schemes including the linear predictive coding scheme and a coding scheme different from the linear predictive coding scheme can be realized.

Abstract: When a frame immediately preceding an encoding target frame to be encoded by a first encoding unit operating under a linear predictive coding scheme is encoded by a second encoding unit operating under a coding scheme different from the linear predictive coding scheme, the encoding target frame can be encoded under the linear predictive coding scheme by initializing the internal state of the first encoding unit. Therefore, encoding processing performed under a plurality of coding schemes including the linear predictive coding scheme and a coding scheme different from the linear predictive coding scheme can be realized.

Abstract: A linear prediction coefficient of a signal represented in a frequency domain is obtained by performing linear prediction analysis in a frequency direction by using a covariance method or an autocorrelation method. After the filter strength of the obtained linear prediction coefficient is adjusted, filtering may be performed in the frequency direction on the signal by using the adjusted coefficient, whereby the temporal envelope of the signal is shaped. This reduces the occurrence of pre-echo and post-echo and improves the subjective quality of the decoded signal, without significantly increasing the bit rate in a bandwidth extension technique in the frequency domain represented by spectral band replication.

Abstract: It is provided a voice activity decision apparatus capable of accurately performing the decision on the state being associated with a sound interval or a silence interval also in terms of the input signal having many aperiodic components and/or plural mixed different periodic components. The apparatus 1 comprises: an autocorrelation calculating unit 11 for calculating autocorrelation values of an input signal; a delay calculating unit 12 for calculating plural delays at which autocorrelation values calculated by the autocorrelation calculating unit 11 become maximums; a noise deciding unit 13 for deciding whether the input signal is a noise or not based on the plurality of delays calculated by the delay calculating unit 12; and an activity decision unit 14 for performing the activity decision in terms of the input signal based on results of decision by the noise deciding unit 13 and the input signal.

Abstract: A linear prediction coefficient of a signal represented in a frequency domain is obtained by performing linear prediction analysis in a frequency direction by using a covariance method or an autocorrelation method. After the filter strength of the obtained linear prediction coefficient is adjusted, filtering may be performed in the frequency direction on the signal by using the adjusted coefficient, whereby the temporal envelope of the signal is transformed. This reduces the occurrence of pre-echo and post-echo and improves the subjective quality of the decoded signal, without significantly increasing the bit rate in a band extension technique in the frequency domain represented by SBR.

Abstract: When a frame immediately preceding an encoding target frame to be encoded by a first encoding unit operating under a linear predictive coding scheme is encoded by a second encoding unit operating under a coding scheme different from the linear predictive coding scheme, the encoding target frame can be encoded under the linear predictive coding scheme by initializing the internal state of the first encoding unit. Therefore, encoding processing performed under a plurality of coding schemes including the linear predictive coding scheme and a coding scheme different from the linear predictive coding scheme can be realized.

Abstract: To provide a data transmitter-receiver bidirectional transmitting system, and data transmitting-receiving method capable of reducing influences of a transmission delay when performing bidirectional communication with an other-communication-party apparatus in an environment in which various states are dynamically changed depending on time. A data obtaining portion 11 of a terminal 10 obtains positional directional information D(Tn) and a time information obtaining portion 12 obtains time information Tn. The terminal 10 stores D(Tn) and Tn in a memory portion 13 and a transmitting portion 15 transmits D(Tn) and Tn to a server 20. A data generating portion 21 of the server 20 generates stereophonic data S(Tn) by using D(Tn), a time information copying portion 22 copies Tn, a transmitting portion 24 transmits S(Tn) and Tn to the terminal 10.

Abstract: The present invention intends to render quantization noise virtually imperceptible for a user and to prevent reduction in frequency resolution and reduction in encoding efficiency.

Abstract: A decoding apparatus is provided. The decoding apparatus has a first decoding part for decoding a code word obtained by encoding an input signal using a Code-Excited Linear Prediction encoding method. A second decoding part decodes a code word obtained by encoding a signal with an encoding method other than the Code-Excited Linear Prediction encoding method. A rising-transition detection and notification part has a detection part that detects the existence of a rising-transition of amplitude of the input signal based on time variation of a gain of excitation vectors obtained by the first decoding part, and a notification part that notifies the second decoding part that the rising-transition of the amplitude exists.

Abstract: A coding device capable of improving the coding efficiency and a decoding device for decoding a code sequence generated by the coding device are provided. In the coding device, for each of the possible block combinations obtained when dividing a frame, a coding unit encodes each block in the frame block by block at different bit rates, and at the same time, the coding unit decodes the resultant code sequences related to the frame. A calculation unit calculates the error powers of the decoded signals and the input signal. A determination unit selects a code sequence that makes the average bit rate in coding the frame not higher than a specified value and the corresponding error power a minimum. This selected code sequence is output.

Abstract: A coding standard selecting method for selecting a coding standard used for communications between a first terminal and a second terminal, each terminal supporting multiple coding standards, is disclosed. The first terminal transmits a first signal representing all the coding standards supported by the first terminal itself to the second terminal. The second terminal selects a set of coding standards that satisfies a predetermined condition from among the coding standards represented by the first signal and among the coding standards supported by the second terminal itself, and transmits a second signal representing the selected set of coding standards to the first terminal. The first terminal selects a coding standard to be used for communication with the second terminal from the set of coding standards represented by the second signal, and transmits a third signal representing the selected coding standard to the second terminal.

Abstract: In a voice communication system 1, a gateway server 4 receives IP packets from the Internet, converts PCM voice data in the IP packets into AMR encoded voice data frames, and transmits to a mobile terminal 7. During the propagation to the gateway server 4, there is a possibility of loss of IP packets and crucial bit error in IP packets. In that case, the gateway server 4 puts “No data” data on frames as voice encoded data for the IP packets in question and sends it to the mobile terminal 7. The “No data” data is a target of concealment.

Abstract: To provide a data transmitter-receiver bidirectional transmitting system, and data transmitting-receiving method capable of reducing influences of a transmission delay when performing bidirectional communication with an other-communication-party apparatus in an environment in which various states are dynamically changed depending on time. A data obtaining portion 11 of a terminal 10 obtains positional directional information D(Tn) and a time information obtaining portion 12 obtains time information Tn. The terminal 10 stores D(Tn) and Tn in a memory portion 13 and a transmitting portion 15 transmits D(Tn) and Tn to a server 20. A data generating portion 21 of the server 20 generates stereophonic data S(Tn) by using D(Tn), a time information copying portion 22 copies Tn, a transmitting portion 24 transmits S(Tn) and Tn to the terminal 10.

Abstract: A delay unit 103 adds holding time that has been set by a holding time setting unit 104 to a received data. The holding time is computed based on delay time of received data and the minimum delay time of data received up to a certain point for the purpose of reducing a total delay time. The delay time is estimated in a delay time estimating unit 106 from the difference between a reception time of a packet counted based on an internal clock generator 107 and a time designated by a time stamp in the received packet.