Showing papers by "Masayuki Nishiguchi published in 1989"

High efficiency encoder for digital data

Abstract: PURPOSE: To efficiently perform encoding by controlling bit allocation corresponding to the detection output of a pattern in the level change of data made into blocks in a time base direction CONSTITUTION: The pattern of the level change of blocked data after passing a blocking circuit 51 in the time base direction is detected, and the bit allocation in quantization at a quantization circuit 67 is controlled corresponding to the detection output Also, each unit time block B (time analysis block) from the blocking circuit 51 is divided into, for example, three; front, medium, and rear sub blocks Sf, Ss, and Se, and for example, the energy values in the sub blocks Sf, Ss, and Se are compared In such a way, the pattern of the level change of the data in the unit time block B (time analysis block) in the time base direction can be detected Thereby, it is possible to perform high efficiency encoding for digital data capable of performing the bit allocation on the optimum frequency axis corresponding to the transient change of an input signal on a time base COPYRIGHT: (C)1991,JPO&Japio

Signal transmission equipment

Abstract: PURPOSE: To transmit a signal by always maintaining a satisfactory conversion gain by preparing plural converting systems, switching and selecting, and encoding the converting system of the height compression efficiency from in these plural converting systems, and also, transmitting selective information and an encoding output CONSTITUTION: The orthogonal transformation of a signal is executed by a conversion matrix of a converting system of the highest compression efficiency switched and selected, based on the quality of an input signal from in a conversion matrix of various converting systems stored in a conversion matrix storage memory 24 in an orthogonal transformation circuit 25 Also, at the time of switching and selecting the conversion matrix in such a case, the result of analysis of the quality of the input signal by a quality analyzing circuit 22 is used Selective information outputted from an optimum conversion matrix selecting circuit 23 is outputted from an output terminal 2 of an encoding circuit 20 as auxiliary information In a decoding circuit 30, a quantizing output is supplied to a inverse quantizer 36, and the selective information is sent to a conversion matrix storage memory 34 in which inverse matrix of various conversion matrixes in the conversion matrix storage memory 24 is stored COPYRIGHT: (C)1991,JPO&Japio

Audio signal reproducing device

Abstract: PURPOSE: To reduce the size and weight of a device main body by using a semiconductor memory as a storage medium for audio data which are compressed and encoded with high efficiency. CONSTITUTION: The semiconductor memory 41 in an audio signal reproducing circuit part 40 is stored with the audio data which are compressed and encoded with high efficiency. Namely, the stored data are obtained by converting an audio signal supplied to an input terminal 31 into a digital signal by an A/D converter 32 and compressing and encoding the digital signal by an encoding circuit 33 with high efficiency, and data read out of the semiconductor memory 41 are converted into an analog signal, which is sent to a headphone unit 44 and converted acoustically. Thus, the semiconductor memory is used as the signal recording medium to reduce the size and weight. COPYRIGHT: (C)1991,JPO&Japio