1
Moriya Takehiro, Mori Takeshi, Ikeda Kazunaga, Iwakami Naoki: Multichannel acoustic signal coding and decoding methods and coding and decoding devices using the same. Nippon Telegraph & Telephone, August 12, 1998: EP0858067-A2 (26 worldwide citation)

In multichannel acoustic signal coding and decoding, left-and right-channel signals are alternately interleaved for each sample to generate a one-dimensional signal sample sequence. The one-dimensional signal sample sequence is subjected to coding based on correlation. In coding, the left- and right ...


2
Iwakami Naoki, Moriya Takehiro, Miki Satoshi: Acoustic signal transform coding method and decoding method.. Nippon Telegraph & Telephone, September 20, 1995: EP0673014-A2 (22 worldwide citation)

An input acoustic signal is subjected to modified discrete cosine transform processing to obtain its spectrum characteristics. On the other hand, linear prediction coefficients are derived from the input acoustic signal in a linear prediction coding analysis part (17), and the prediction coefficient ...


3
Moriya Takehiro, Iwakami Naoki: Multichannel signal coding using weighted vector quantization.. Nippon Telegraph & Telephone, November 29, 1995: EP0684705-A2 (5 worldwide citation)

Disclosed are coding and decoding methods and related coders and decoders, wherein signal components of plural channels are weighted-vector quantized as a single vector produced by combining them together with weights corresponding to their power components. The invention permits production of the q ...


4
Iwakami Naoki, Moriya Takehiro, Jin Akio, Chikira Kazuaki, Mori Takeshi: Audio signal coding and decoding methods and apparatus and recording media with programs therefor. Nippon Telegraph & Telephone, October 25, 2000: EP1047047-A2 (5 worldwide citation)

An input signal is time-frequency transformed, then the frequency-domain coefficients are divided into coefficient segments of about 100 Hz width to generate a sequence of coefficient segments, and the sequence of coefficient segments is split into subbands each consisting of plural coefficient segm ...


5
Moriya Takehiro, Mano Kazunori, Miki Satoshi, Ohmuro Hitoshi, Sasaki Shigeaki, Iwakami Naoki: Method for the modification of plc coefficients of acoustic signals. Nippon Telegraph & Telephone, September 11, 1996: EP0731449-A2 (2 worldwide citation)

In a CELP coding scheme, p-order LPC coefficients of an input signal are transformed into n-order LPC cepctrum coefficients cj (S2), which are modified into n-order modified LPC cepstrum coefficients cj' (S3). Log power spectral envelopes of the input signal and a masking function suited thereto are ...