An Audiovisual Media Substitution System

摘要

Audiovisual substitutional media items are output within a media output stream. The media output stream comprises audio and video streams having mutually different frame rates. A video splice point in the output stream is referenced to a video frame of the video stream. An audio splice point is derived at or immediately after the video splice point and the audio content of the substitutional media item is output from this point. Also disclosed is a method of synchronizing the audio content with the frame timing of the media stream; a method of outputting dummy data depending on the arrival time of the audio content; and a method of outputting dummy data subsequent to the audio content of the substitutional media item if the said output occurs prior to a splice out point. Further disclosed are methods of scheduling media items.