British Telecommunications Public Limited Company

Anthony R Leaning

Richard J Whiting

Michael D Carr

John Martin O'Donnell

Anthony B Leaning

David Dalby

Maurice G Perini

Delivery of recorded audio or video material over a telecommunications link from a server is accomplished by dividing the material into a sequence of sub-files each of which is independently requested by the terminal, which thereby has control of the rate of delivery. Provision may be made for switching between alternative sub-file sets representing alternative delivery modes or data rates.

Transmission and reception of audio and/or video material

A system for transmitting audio signals over a telecommunications link generates the signals as two or more alternative feeds, for example at different data rates. The two feeds are encoded using coding methods having a frame structure with different frame lengths. To facilitate switching between the two, the input signal is notionally divided into temporal portions and each is coded by taking it, plus enough of the next (or preceding) portion to make up a whole number of frames, and encoding it, whereby the encoded portions overlap&#x2014;at least for one of the feeds. The overlap is lost upon decoding by discarding duplicate material.

Audio signal encoding method combining codes having different frame lengths and data rates

Video coding

Signal coding

Pattern processing

Growing community of inventors

Ipswich, United Kingdom

Anthony R Leaning