Dieter Seitzer

Method of coding a plurality of audio signals

In a method of coding a plurality of audio signals, the left and the right basic channel as well as the central channel are combined by joint stereo coding so as to obtain a jointly coded signal, which is decoded so as to provide simulated decoded signals. The simulated decoded signals and two surround channels are combined by matricization by means of a compatibility matrix so as to form compatible signals which are suitable for decoding by existing decoders. In order to avoid audible disturbances caused by excessive energy contents of the compatible signals, which would occur if joint stereo coding and decoding were carried out prior to carrying out the matricization, the compatible signals or the simulated decoded signals are dynamically weighted by means of a dynamic correction factor in such a way that the compatible signals are approximated with regard to their energy to the energy of signals which would be obtained if the two basic channels and the central channel as well as the surround channels were matricized directly.

Apparatus for checking audio signal processing systems

Disclosed is an apparatus for checking audio signal processing systems. The apparatus has the following features: the apparatus is provided with a first input connection, to which the input signal of the audio processing system to be checked is transmitted, a second input connection, to which the output signal of said system is transmitted, and a signal processor. said signal processor ascertains the signal delay time of said system to be checked by means of correlating said signals received at said two input connections, said signal processor always composes the difference signal from said signal received at said first input connection during a specific time span and said signal received at said second input connection, lagging by the signal delay time, said signal processor ascertains the spectral composition of said signal received at said first input connection during said specific time span and of said respective difference signal, said signal processor ascertains the hearing threshold of the human ear from said spectral composition and compares the ascertained hearing threshold with the respective difference signal.

Digital coding of high quality audio

Based on frequency-domain techniques, coding of high-quality audio with bit rates down to 64 kbit/s is possible. This performance is achieved using perceptual coding. Transform coding can be used to get the best performance at very low bit rates. Real-time implementations of several types of low bit rate codecs have been developed. Standardization of low bit rate audio coding systems is under way in ISO/IEC JTC1/SC2/WG11 (MPEG/Audio).<<ETX>>

Instantaneous Priority Multiplexing of Gray Pictures

In a multichannel picture transmission system data rate reduction can be achieved by multiplexing. The multiplexer essentially consists of a switch which interconnects a particular scanner to the transmission channel. The position of the switch is controlled by features such as significant changes derived from the pictures to be transmitted. Economy seems favorable due to the sharing of most of the equipment.

A CODEC CHIP ARCHITECTURE FOR (24,12,8) GOLAY CODE WITH THE PERMUTATION DECODING

Abstract — An efficient ASIC chip of the Golay codec has been designed for channel coding. This paper describes the new architecture used in this chip and the ASIC design. Due to the new architecture which implements a permutation decoding algorithm based on a new minimum permutation set proposed by [6], the codec architecture is relatively simple and a higher speed of the decoding procedure can be achieved compared with the Golay decoder of the decoding algorithms in common use, error-trapping algorithm and step-by-step method. From [7], Kasamis error-trapping decoder requires 46 shift-operations for decoding one completely received word and the modified step-by-step decoder[7] requires 35 shift operations, while our decoder requires only 14 permutation operations, generalized shift operations. Consequently, this decoder can work faster than the Kasamis error-trapping decoder and the modified step-by-step decoder[7].

IMPACT OF MICROELECTRONICS - TECHNICAL, ECONOMICAL AND SOCIAL ASPECTS

Scientists make research, politicians carry responsibility? This is a provocative question. The purpose of this contribution is to improve the necessary information exchange between those who develop microelectronics technology and those who are affected by it. By communicating its various implications in industry, economy and society, the objective of an improved sharing of the function of technological development and responsibility for the consequences can be approached. Aspects of technology itself, especially those of physical limitations that are the subject of companion papers, are excluded from consideration. Extensive use is made of source material presented in “Microelectronics and Society — For Better or For Worse” 1, of a series of public papers edited under the title “Microelectronics, Information, Society”2 and an earlier paper.3