Method and apparatus for reducing start-up delay in data packet-based network streaming applications

Abstract

A method and apparatus which reduces the start-up delay that may occur when switching programs in audio and/or video streaming applications while maintaining high quality steady-state performance thereof. A program source (e.g., an audio and/or video data stream) is encoded and transmitted as two or more separate bit streams (e.g., sequences of data packets), the transmission of one of these bit streams being delayed by a given amount of time relative to the transmission of the other bit stream(s). At the receiving end of the transmission channel, the two or more bit streams are buffered by receive buffers having different sizes (thereby resulting in different time delays when the contents thereof are decoded), wherein the time delay difference corresponds (inversely) to the relative delay times prior to transmission. Advantageously, either a multiple descriptive source coding scheme or an embedded coding scheme may be employed, in which at least one of the individual bit streams is sufficient to obtain a satisfactory decoded signal, but wherein the addition of the other bit stream(s) will improve the quality of the decoded signal. Alternatively, the data streams may comprise multiple encodings of the program source having different bit rates, wherein the lower bit rate encodings are transmitted with the correspondingly larger delays.