| 摘要 |
<p>A method of encoding a framed media stream at an encoder for broadcast at a headend, the encoded media output stream including a splice point message referenced to a frame of the media stream at a time indicated by a media scheduler, the method comprising synchronising the frame timing of the encoder to the timing of the media scheduler. The insertion point message may indicate the precise video frame at which a splice point will occur, which may be a fixed interval before the occurrence of the splice point. The media scheduler and encoder may be synchronised to a common clock reference. The television media scheduler, such as an Electronic Programme Guide (EPG), may output a clock signal to the encoder for synchronisation purposes. The Coordinated Universal Time (UTC) may be inserted at which the frame is played out and sent to the input of the encoder in the Vertical Interval Time Code (VITC) field of the frame. The claimed method and encoder are used as part of an audiovisual (A/V) media substitution system designed for targeted advertising.</p> |
