Abstract: In an encoder for decoding compression data obtained by conducting a compression encoding for digital data through subband division, logarithmic compression, and variable-bit-length quantization, an exponent of an exponent operation is separated into an integer part and a fraction part to obtain an operation formula such that an operation related to the fraction part is executed through a multiplication and an operation associated with the integer part is accomplished through a shift operation. In addition, using a correlation between results of the calculations, the number of calculation steps is reduced. Moreover, one type of information data is written in an area in which another type of information data is beforehand written so as to minimize the necessary memory capacity.

Abstract: A decoder for decoding compressed data obtained through compression of digital data based on a high efficiency coding technique. The compressed data is processed in units of a predetermined amount of data and the predetermined data unit contains information indicative of a first point of time at which the data unit is to be output from the decoder.

Abstract: An audio signal data processing system comprises input device for sequentially supplying an audio signal data, data memory control device for writing the audio signal data into a data memory and reading-out the data from the data memory, delay memory control device for sequentially reading-out the audio signal data from the data memory and storing the data into a location of a delay memory indicated by a writing address and for reading-out the audio signal data from a location of the delay memory indicated by a reading address and writing the data into the data memory, address designating devices for designating the writing and reading addresses, arithmetic device for multiplying a predetermined coefficient data to the audio signal data having been read-out by the delay memory control device and written into the data memory, and output device for providing the audio signal data in accordance with a result of operation by the arithmetic device.

Abstract: An audio signal data processing system includes first and second processing devices for processing audio signal data, the first and second processing device having input and output ports of at least two channels, and a control device for controlling the operation of the first and second processing device. The input audio signal data is supplied to the input port of one channel of each of the first and second processing devices, and output data from the output port of said one channel of said first processing device is supplied to the input port of the other channel of the second processing device, and output audio signl data are obtained at each output port of both channels of the second processing device. With this arrangement, one of the cascade processing and the parallel processing can be selectively performed without using a change-over switch provided outside the system.