Abstract: Reproduction accuracy of a digital signal, representing, for example, stereo audio signals, is improved by transmitting sample data which have been encoded to form transmission signals. The stereo audio signals are coded into sub(band) signals. Corresponding sub(band) signals of the stereo audio signals may be processed to obtain composite sub(band) signals, which are recorded on a record carrier. To identify whether corresponding sub(band) signals have been processed or not, a mode indicator control signal, indicating whether a corresponding sub signal of the at least two signal components have or have not been processed into a composite sub-signal, is also being recorded on the record carrier.

Abstract: Reproduction accuracy of a digital signal, representing, for example, stereo audio signals, is improved by transmitting sample data which have been encoded to form transmission signals. The stereo audio signals are coded into sub(band) signals. Corresponding sub(band) signals of the stereo audio signals may be processed to obtain composite sub(band) signals, which are recorded on a record carrier. To identify whether corresponding sub(band) signals have been processed or not, a mode indicator control signal, indicating whether a corresponding sub signal of the at least two signal components have or have not been processed into a composite sub-signal, is also being recorded on the record carrier.

Abstract: Reproduction accuracy of, for example a digital stereo audio signal, is improved by transmitting sample data as sub-signals such as frequency subband signals. In one or more subbands, corresponding components such as left and right stereo channels are combined so that only one composite signal is transmitted per subband. An indicator signal is transmitted, indicating which subbands are combined. Scale factor signals for all subbands, and for the relative intensity of the respective subband signals which were combined, may also be transmitted. In the receiver a subband signal is derived for each channel from the composite signal, before synthesis of the full channel signals which will be reproduced.

Abstract: In the transmission of audio signals, the audio signal is digitally represented by use of quadrature mirror filtering in the form a plurality of spectral sub-band signals. The quantizing of the sample values in the sub-bands, e.g. 24 sub-bands, is controlled to the extent that the quantizing noise levels of the individual sub-band signals are at approximately the same level difference from the masking threshold of the human auditory system resulting from the individual sub-band signals. The differences of the quantizing noise levels of the sub-band signals with respect to the resulting masking threshold are set by the difference between the total information flow required for coding and the total information flow available for coding. The available total information flow is set and may then fluctuate as a function of the signal.