Patent Application
20100218207
The disclosure relates generally to television systems.
Cable and content providers frequently promote specific pay channels by airing them unencrypted for a fixed period of time. However, it is difficult to keep track of the free previews and hence many customers miss the free previews particularly if they do not subscribe to a cable box, for example.
Currently, customers know of unencrypted previews via written advertising brochures they typically receive in the mail from the cable operator. Once the time period lapses for viewing the free preview, the cable providers re-encrypt the channels unless a customer pays for the viewing of the channel. Digital televisions and cable boxes typically detect and disable channels from a broadcaster that are encrypted and a user is typically simply shown a screen that states that the programming that they are attempting to view on a particular channel or subchannel is unavailable and that a fee must be paid to view the programming.
It is known to use television receivers to detect scrambled incoming transport streams so that the television does not display blank screens. Instead, a blue screen or a still image screen with text may be displayed. Also, channel scanning is known which is typically performed, for example, when using a single tuner at a point in time when the user believes that the television is off. This is typically referred to as a background channel scan which searches for electronic programming guide information, for example. If multiple tuners are present in a digital television, then background scans can be performed using the tuner that is not being tuned to a current channel that is being watched. However, such prior art systems do not provide a solution to eliminating the need for a user having to manually keep track of when preview content will expire or when unencrypted information is now available for viewing. A need exists to improve the revenue generating stream for broadcast content that employ preview content such as temporarily unencrypted and encrypted program information.
The invention will be more readily understood in view of the following description when accompanied by the below figures and wherein like reference numerals represent like elements, wherein:
Briefly, a method and apparatus detects a presence of a change in encryption status of video information, such as a program preview, in a video stream. The method and apparatus issues notification information such as through a visual user interface, audibly or in any other suitable manner, that new content, such as a pay per view video information, is either available or unavailable based on the detection of a change in encryption status of the video information. Among other advantages, an interactive and automated technique is provided to inform a user while, for example, the user is watching a display device, that a preview of content is now available or that a previously available preview has now changed and is now encrypted and therefore a user must order the previewed content before an expiration period occurs. In this fashion, a user is automatically notified that a free preview is available, while watching television and a broadcaster may increase revenues since preview information is more readily detected and presented to potential customers.
In one example, the detection of a presence of a change in encryption status of video information is done by evaluating broadcast system information that has been embedded in a broadcast stream. The broadcast system information may be, for example, program map table information, channel map table information or any metadata embedded in an incoming video stream that indicates that a video preview is encrypted or unencrypted. In this way, a video receiver system can detect the embedded information to determine whether incoming video previews are encrypted or unencrypted without having to analyze the actual packets that make up the video preview. In another example, the detection of a presence of a change in encryption status information may include performing a channel scan on a transport stream and determining which subchannels of a channel are encrypted. This may be done, for example, when tuned to a corresponding channel that has encrypted subchannels. A check is then performed for a change in encryption status of the encrypted subchannels. In another example, instead of performing a channel scan, an audio and video decoder may be employed to determine if video information is unscrambled as part of the decoding process. In another example, instead of a transport stream based detection method, a Packetized Elementary Stream (PES) detection process may be used as part of the setup of audio and video decoding process to determine whether a change in encryption has occurred for content. However, it will be recognized that any other suitable techniques of detecting a change in encryption status may also be employed.
In another example, a channel scan may be performed and the detection of the presence of a change in encryption status may occur by determining from program map table information, whether a program is encrypted or decrypted. A visual display of information may also be produced that contains a combination of a plurality of channel identifiers such as channel name or channel number along with corresponding encryption status data for each of the plurality of channel identifiers along with purchase information to allow a viewer to purchase preview content. As such, a user interface may be provided with data representing ordering information corresponding to video identified by the preview of content in response to detection of change from an encrypted to a decrypted status.
The incoming video information 14 may be, for example, an ATSC, DVB, ISDB compliant stream or any other suitable broadcast information. The controller 24 is operative to carry out conventional DTV tuning operations such as facilitating channel scans by outputting channel tune information 30 to control the video receiver 12 to tune to a particular channel or subchannel as known in the art. The controller 24, demultiplexer 18 and decoder 32 may be integrated, for example, on one or more integrated circuit dies and may be of the type, for example, of the Xilleon type chips produced by ATI Technologies, Inc., Thornhill, Ontario, Canada, or any other suitable structure. The controller 24 is a digital processor that executes instructions that are stored in memory (e.g., ROM, RAM, etc.) located on chip or off chip as desired. The controller 24 unlike conventional digital television circuits includes additional logic (e.g., a processor executing new software stored in memory) that detects the presence of a change in encryption status of video information in the video stream 14 and produces viewer notification information 34 that is displayed on a display 36. The viewer notification information 34 indicates that new content is available or unavailable. The viewer notification information 34 is produced based on the detection of the change in encryption status of the video information. The display 36 such as an LCD display, plasma or any other suitable display, displays the viewer notification information 34 for a user. This may be done by using an image processor 38, as known in the art that presents information for display. The image processor 38 may receive the decoded video and audio information 40 from the decoder as known in the art and display it on the display 36 in any suitable format including in any desired location on the screen, in any desired size and in any desired resolution.
The demultiplexer 18 also outputs decoded audio and video data 44 that may be decoded by conventional decoder 32. The decoder 32 may include an audio decoder 46 and a video decoder 48 also as known in the art.
Referring also to
By way of example, detecting the presence of a change in encryption status information wherein broadcast system information is used, the broadcaster or any other entity may embed data in the video stream that indicates whether a video preview is encrypted or unencrypted. As described above, the broadcast system information may be for example, metadata in broadcast tables that indicates whether or not intended preview content is encrypted or unencrypted. In one example the controller 24 detects this data that is inserted in tables and looks for a change in status of the data as it processes incoming video streams for channels or subchannels.
In an alternative operation, the controller 24 may maintain in its local memory (e.g. RAM) or other suitable memory, a cache of current channels and compare the cached current channel with the broadcast system information embedded in the video stream to determine if an incoming video stream contains different preview content from the cached channel.
In an alternative embodiment where no broadcast system information has been embedded in the video stream to indicate whether the video preview is encrypted or unencrypted, a detection of a presence of a change in encryption status of information (e.g., intended as preview content), includes performing a channel scan on the transport stream 16 and determining which subchannels of a channel are encrypted, when tuned to a corresponding channel that has encrypted subchannels. This may be performed for example by the controller 24. The controller 24 may perform a check for a change in encryption status in the encrypted subchannels. If desired, the channel scan may occur when the apparatus 10 is in a standby condition such as a standby mode and perform a background scan of only encrypted subchannels. If a change in encryption status is detected, the controller may then wait to inform a viewer until after subsequent “power on” of the apparatus 10 occurs.
Detecting the presence of a change in encryption status may also include for example the controller 24 determining whether header information of one or more packets of video information in the transport stream 16 indicates that the video information is encrypted. As noted above, this header information may be one example of broadcast system information that is embedded in the video stream. Detecting a presence of a change in encryption status with respect to header information may include using PES header information to determine if audio or video is encrypted. Bits in a header may be inserted into a PES header that are detected by the controller 24 to indicate whether or not the transport stream being processed for a given program has changed in its encryption status.
Another approach for detecting the presence of the change in encryption status may include during a channel scan, determining from program map table information, whether a program is encrypted or decrypted. Program map tables (PMT) are known structures in ATSC type streams. For example, new data may be included in the PMT to indicate whether a channel/subchannel is encrypted or unencrypted.
As another alternative approach, the controller 24 may not detect embedded information in the transport stream but may instead detect the presence of a change in encryption status by using decoded audio and/or video information that is output from decoder 32, for example shown by dashed line 50 (
As described above, several techniques are disclosed that can be used to detect a presence of a change in encryption status of video information such as content to be previewed by a viewer. In several of the techniques, metadata is embedded in the transport stream and then received by the receiver. For example program map table information such as conditional access descriptors in the PMT may be analyzed during, for example, an initial channel scan process to detect whether a change in encryption status has occurred. The controller 24 can evaluate the new PMT information to make the decision. In another example header in packets can identify whether a packet includes scrambled information. The controller 24 looks at the packets over time to determine whether information has been scrambled. In another example, the PES header may be used to indicate if audio or video is scrambled. These techniques for example do not require the use of the audio/video decoder pipeline. In other examples, the audio/video decoder is used so that audio and video pipelines are used to determine for example that no pictures or audio are present. If not present, the controller 24 determines that a channel is scrambled.
Referring to
A visual user interface indicates that at least one preview of content has been detected in response to the detection from encrypted to decrypted status. This is shown for example in
A “new content” screen as shown in
Among other advantages, an automatic detection of when a viewable preview is available is provided and the user is automatically informed of detection of any preview or channel to which the user can view content as unencrypted content as well as notifying the user that previously unencrypted content that the user could preview, has now been encrypted so that the preview has expired. The user is then given the option to purchase the preview content. Accordingly, automatic detection and user feedback is provided indicating a change to a scrambled channel. Other advantages would be recognized by those of ordinary skill in the art.
Also, integrated circuit design systems (e.g. work stations) are known that create integrated circuits based on executable instructions stored on a computer readable memory such as but not limited to CDROM, RAM, other forms of ROM, hard drives, distributed memory etc. The instructions may be represented by any suitable language such as but not limited to hardware descriptor language or other suitable language. As such, the logic (e.g., circuits) described herein may also be produced as integrated circuits by such systems. For example an integrated circuit may be created for use in a display system using instructions stored on a computer readable medium that when executed cause the integrated circuit design system to create an integrated circuit that is operative to detect a presence of a change in encryption status of video information in a video stream and notify a viewer that new content is available or unavailable based on the detection of the change in encryption status of the video information. Integrated circuits having the logic that performs other of the operations described herein may also be suitably produced.
The above detailed description of the invention and the examples described therein have been presented for the purposes of illustration and description only and not by limitation. It is therefore contemplated that the present invention cover any and all modifications, variations or equivalents that fall within the spirit and scope of the basic underlying principles disclosed above and claimed herein.
