Audio encoder for use with more than one decoder each having different characteristics
US4815068A · kind A · utility
Inventors
Key dates
| Filing date | Aug 7, 1987 |
| Grant date | Mar 21, 1989 |
| Priority date | — |
| Expiry date | Aug 7, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A "hybrid" encoder has a characteristic action suitable for substantially full complementary playback in an audio signal transmission or recording system using decoders designed for one type complementary encode/decode system while permitting compatible decoding with decoders designed for use with another type complementary encode/decode system, or playback without any special decoders at all. The hybrid encoder is a series or parallel arrangement of two encoders that are modifications of standard encoders used in the two systems. In the preferred embodiments the two systems are A-type noise reduction and spectral recording. A variable degree of hybrid encoding is provided by varying the characteristic controlling circuit parameters in the two encoders, or in a preferred embodiment, by providing a variable combining arrangement that selects selects from the outputs of a hybrid encoder and an unmodified encoder (spectral recording).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.