| 摘要 |
<p>A digital broadcast station (50) is configured to 'turn around' and add interactive programming to a television signal conveyed by a remote network (10). Prior to conveying the television signal, the remote network inserts a trigger within the vertical blanking interval of the signal. The trigger contains command information to control the loading and/or playing of a designated interactive program. After the trigger is combined with the television signal, the combined signal is modulated and transmitted from the remote network via a satellite uplink (62). This combined signal is correspondingly received at the digital broadcast station where it is digitized and routed through a video network for channel assignment and other processing. From the video network, the digitized television signal is provided to a VBI decoder which extracts the trigger. The extracted trigger is provided to an interactive flow manager and server to control the loading or playing of an interactive program identified by the trigger. The remainder of the digitized television signal is provided to a video encoder where it is compressed. An AVI generation unit of the digital broadcast station then combines the compressed television signal and the interactive program to form an AVI signal to be broadcast to end users via a satellite uplink.</p> |
