摘要:
A television menu system generates a television menu that is context sensitive based upon a service currently being provided to a user. In one implementation, a type of television service currently being viewed by a user determines whether particular menu items are presented to the user. In another implementations, determining which channel is being provided dictates whether particular menu options are included.
摘要:
A reprogrammable subscriber terminal of a subscription television service which can have the control program code of its control processor modified by downloading new program code from the headend. The control processor stores a boot program in an internal read only memory. Upon start up and resets, the boot program determines whether the control program should be changed from a command sent from the headend. The command, termed a parameters transactions, includes the number of expected download program code transactions required to complete the control code modification, the memory space areas where the code is to be loaded, and the channel over which the download program code transactions are to be transmitted. The channel is tuned and when the boot program receives all the download program code transactions accurately and stores them, the boot program will cause the control program to be restarted at a selected address of the new or modified control program code which has been downloaded. The boot program may download code to different configurations of subscriber terminals including those with Flash EPROM or extended memories from plug-in expansion modules.
摘要:
A cable television system provides conditional access to services. The cable television system includes a headend from which service “instances”, or programs, are broadcast and a plurality of set top units for receiving the instances and selectively decrypting the instances for display to system subscribers. The service instances are encrypted using public and/or private keys provided by service providers or central authorization agents. Keys used by the set tops for selective decryption may also be public or private in nature, and such keys may be reassigned at different times to provide a cable television system in which piracy concerns are minimized.
摘要:
A reprogrammable subscriber terminal of a subscription television service which can have the control program code of its control processor modified by downloading new program code from the headend. The control processor stores a boot program in an internal read only memory. Upon start up and resets, the boot program determines whether the control program should be changed from a command sent from the headend. The command, termed a parameters transactions, includes the number of expected download program code transactions required to complete the control code modification, the memory space areas where the code is to be loaded, and the channel over which the download program code transactions are to be transmitted. The channel is tuned and when the boot program receives all the download program code transactions accurately and stores them, the boot program will cause the control program to be restarted at a selected address of the new or modified control program code which has been downloaded. The boot program may download code to different configurations of subscriber terminals including those with Flash EPROM or extended memories from plug-in expansion modules.
摘要:
A cable television system provides conditional access to services. The cable television system includes a headend from which service “instances”, or programs, are broadcast and a plurality of set top units for receiving the instances and selectively decrypting the instances for display to system subscribers. The service instances are encrypted using public and/or private keys provided by service providers or central authorization agents. Keys used by the set tops for selective decryption may also be public or private in nature, and such keys may be reassigned at different times to provide a cable television system in which piracy concerns are minimized.
摘要:
A near video on demand time shifting feature for a subscriber terminal emulates the video cassette recorder functions of pause, fast forward, and rewind for a NVOD service subscription. The subscriber terminal stores global transactions concerning NVOD events in an event portion of memory. The subscriber terminal provides an on screen display feature for assisting in ordering the NVOD service and a user interface which provides the functions of pause, fast forward and rewind. When viewing a NVOD event, if the subscriber selects the pause function, the subscriber terminal causes a pause on screen display to be viewed for one time increment. After the elapse of the time increment, the subscriber terminal will tune the channel of the next showing which is one time increment earlier than that presently viewed. If the subscriber selects the rewind function, the subscriber terminal will tune the channel of the next showing which is one time increment earlier than that presently viewed. If the subscriber selects the fast forward function, the subscriber terminal will tune the channel of the previous showing which is one time increment later than that presently received.
摘要:
A subscriber terminal apparatus for a television in an in-band subscription television system is provided. The subscriber terminal includes a receiver for receiving a television signal including video, audio, ana data information. A selector selects a channel of the television signal. A memory stores a plurality of barker screens providing messages regarding one or more channels of the television signal. An on-screen display control circuit controls the display of the barker screens on the television. A processor retrieving a barker screen from the memory supplies the retrieved screen to the on-screen display control circuit if the barker screen provides a message regarding a selected channel. Barker screen information may also be obtained from a dedicated data channel or a six megahertz video barker channel.
摘要:
Sync suppressed television signals transmitted with timing pulses in dynamically variable time delayed relationship with respect to the suppressed sync pulses are descrambled with a high degree of noise immunity by decoding tag pulses transmitted with the timing pulses into a digital signal representing the dynamically variable time delay relationship in terms of the number of such tag pulses during a predetermined period of time during each field of the TV signal, into a digital signal. The decoding is carried out to provide the digital signal with different values for different groups, each containing a different number of tag pulses. The pulses which restore the sync pulses in the TV signal in each field are timed with respect to the timing pulses in accordance with the value of the digital signal. Dynamic delay variations which vary from field to field or for any selected number of fields, during any selected period of time, may be accommodated in the descrambling of the TV signals and with high noise immunity due to the use of groups of tagging pulses in the decoding of the dynamically varying delays.
摘要:
A VIR signal detector circuit for a color television receiver identifies the repetitive reception of a VIR color information signal on a predetermined horizontal line of video signal. The detection is accomplished with minimum interference from Gaussian and pulse-type noise to assure that VIR color control circuits in the receiver are activated only upon receipt of an actual VIR signal. The VIR signal detector operates by generating a viewing pulse of short duration during each horizontal line in which a VIR signal may be present. An accumulator, set to respond to a predetermined number of simultaneous detections of the viewing pulse and a video signal exceeding a predetermined value, generates a control signal indicating that a VIR signal is being received.