U.S. Philips Corporation

Koninklijke Philips Corporation N.v.

Gerhard J Stoll

Yves-Francois Dehery

Gerardus C Lokhoff

Gerardus C P Lokhoff

Günther Theile

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.

Record carrier having an encoded wide-band digital audio signal recorded thereon

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.

Subband coded digital transmission system using some composite signals

A transmission channel may be utilized for a combination of wide-band signals and auxiliary signals, while still providing improved reproduction accuracy. Digital sub-signals or subband signals representing at least first and second data-reduced components are combined with at least one auxiliary digital signal in defined frame portions before transmission. The auxiliary signal may be user-discernible information such as third and fourth audio channels, so that a four channel surround sound signal is transmitted; or teletext or video or picture information may be provided. Sampling reduction and filtering into subbands may be applied to the auxiliary signal as well as to the first and second signal components.

Growing community of inventors

Munich, Germany

Gerhard J Stoll