Methods and systems for fast channel change between logical channels within a transport multiplex

摘要

A system, method and computer program product are provided for fast channel change between logical channels within a transport multiplex. By reducing the amount of time it takes to acquire and display a tuned channel, fast channel change can improve a viewer's experience. In exemplary embodiments of the present invention, a fast channel change system can simultaneously decode channel data for each channel in a transport multiplex, reconstruct all access units for each channel and send them out on their respective channel stream in the order that each access unit completes to a streamer, store and maintain a minimum amount of channel data in a buffer in each streamer, and output channel data from a streamer corresponding to a tuned channel to a media player. In exemplary embodiments of the present invention data can be input to a de-multiplexer and divided into separate video and audio streams prior to being input to the media player. Exemplary embodiments of the present invention can be utilized in various video applications, such as, for example, Sirius Satellite Radio's Backseat TV™ service.

主权项

1. A method for fast channel change between logical channels within a transport multiplex, comprising:
receiving a channel selection signal identifying a tuned channel; simultaneously decoding channel data for each channel in a transport multiplex; reconstructing all access units for each channel and sending them out to a streamer on their respective channel stream in the order that each access unit completes; outputting channel data from a streamer corresponding to the tuned channel to a media player; and for each non-tuned channel, storing and maintaining a minimum amount of channel data in a buffer in its streamer by:
recording:each key frame's starting position in the buffer;a minimum necessary amount of video data to store after each key frame to prevent underflow in the event of a channel change to that channel; anda quantity of non key frame data stored since the last key frame, and
discarding data stored previous to the last stored key frame if said quantity is greater than or equal to said minimum necessary amount, and otherwisediscarding data stored previous to the second to last stored key frame if said quantity is less than said minimum necessary amount.