Title of Invention	AN IMPROVED TELEVISION RECEIVER FOR SELECTING TWO DATA STREAMS
Abstract	This invention relates to an improved television receiver for selecting two data streams, a source of digital data comprising a plurality of data streams each representing one of a standard definition television signal and a high definition television signal and encoded in such a manner that the data streams may be decoded at full resolution to produce an image substantially without visible decoding artifacts or decoded at partial resolution to produce an image with visible decoding artifacts; a decoder (10) coupled to the digital data source, having a maximum decoding bandwidth less than that required to simultaneously decode two high definition television signals at full decoding resolution; and a controller (112), coupled to the decoder, for selecting two respective ones of the data streams responsive to user input, and if both represent a high definition television signal, requesting user input for specifying one of the two respective data streams to decode at partial resolution.

Title of Invention

AN IMPROVED TELEVISION RECEIVER FOR SELECTING TWO DATA STREAMS

Abstract

This invention relates to an improved television receiver for selecting two data streams, a source of digital data comprising a plurality of data streams each representing one of a standard definition television signal and a high definition television signal and encoded in such a manner that the data streams may be decoded at full resolution to produce an image substantially without visible decoding artifacts or decoded at partial resolution to produce an image with visible decoding artifacts; a decoder (10) coupled to the digital data source, having a maximum decoding bandwidth less than that required to simultaneously decode two high definition television signals at full decoding resolution; and a controller (112), coupled to the decoder, for selecting two respective ones of the data streams responsive to user input, and if both represent a high definition television signal, requesting user input for specifying one of the two respective data streams to decode at partial resolution.

Full Text	Field of the Invention. The present invention relates to a system and user interface for processing digital data, containing a plurality of time multiplexed data streams, some of which represent video signals, and in particular coded high-definition (HD) video signals, to derive a decoded video signal suitable, for example, for recording or producing a picture-in-picture (PEP) or other reduced resolution purposes. Description of the Prior Art: Television receivers are known that, while displaying a relatively large picture derived from a primary television channel, also can simultaneously display a small subimage such as a picture-in-picture (PIP) derived from a secondary television channel. For high-definition television (HDTV) receivers, the large picture may be derived from a high-definition source, and be displayed with a corresponding high visual resolution. However, because the PEP is small, there is no need to provide a high definition PIP display because a viewer inherently would not be able to resolve the higher definition components of a high definition PEP. Viewers also sometimes desire to record television signals. Standard analog video cassette recorders (VCRs) cannot record HDTV signals at their full resolution. Therefore, before a HDTV channel may be recorded on a standard VCR, it must be transformed into a lower resolution e.g. NTSC format video signal. This lower resolution signal may then be supplied to the VCR. In a digital television signal distribution system, a plurality of digital data streams, each representing a respective video signal, are time multiplexed together and transmitted to the receiver, in a known manner. The digital data in each of the plurality of data streams is encoded and highly compressed according to known encoding schemes, such as MPEG encoding, and must be decoded to regenerate any of the video signals represented by it. Known HDTV receivers include a relatively complex and expensive decoder that conforms with the ISO 1 3818-2 standard for decoding a received coded HD video signal in real time to generate a high-definition video signal for the high definition display device in the receiver. This decoder uses all of the transmitted data in the data stream representing that video signal to reproduce the high-definition video signal representing the transmitted image. However, as described above, a lower resolution video signal is generated for a PIP and/or VCR. This process involves two steps. First, the digital data stream is decoded into a video signal represented by that data stream. Second, this video signal is sample-rate-converted to the lower resolution, e.g. NTSC, video format. To provide the PIP and/or VCR video signal, known HDTV receivers also include a second, lower-resolution, simpler and less expensive, decoder which also conforms with the ISO 13818-2 standard. This decoder, however, uses only a portion of the transmitted data in the data stream representing that video signal to reproduce a low-definition video signal representing the transmitted image. Consequently, this video signal possibly represents an image which contains visible and objectionable artifacts. For a PIP image, this is not a problem, because the small size of the PIP image makes such artifacts practically invisible to the viewer. However, an image to be recorded and played-back will most likely be displayed at full size, allowing these artifacts to remain visible, and possibly objectionable. If a high- definition TV program is selected to record, a choice exists for how to produce the low- resolution video signal. First, the high definition video data may be first decoded using the low resolution decoder. This produces a low resolution video signal having artifacts, as described above. This low-resolution signal is then scan-rate-converted into the low resolution, e.g. NTSC, format. Alternatively, the high resolution data may be first decoded using the high resolution decoder. This produces a high resolution video signal free of artifacts. This high resolution signal is then scan-rate-converted into the low resolution, e.g. NTSC, format. 3 A receiver including nvo decoders is relatively expensive. Further developments have led to an arrangement in which a single decoder was able to be "shared" by two video data streams. Such a decoder was developed which was time multiplexed to be able to decode multiple data streams from the time multiplexed data stream. Such a decoder produces two output signals independently, representing two of the plurality of video signals in the data stream. However, a practical single decoder may not be constructed in an economical manner to simultaneously decode two HDTV signals. Instead, such a decoder may decode a single HDTV signal, and a second signal decoded at lower resolution. A number of problems arise in providing a User interface suitable for operation of an HDTV (or other digital TV) receiver employing decoder units capable of simultaneously processing multiple images for display and/or recording. Such problems arise because of the increased number of processing options available to a User, bandwidth constraints of the decoder, and different system and peripheral configurations (e.g. different storage and playback units) that may be used in an HDTV entertainment system. These problems and derivative problems are addressed by a system according to the present invention. SUMMARY OF THE INVENTION In accordance with principles of the present invention a television receiver includes a source of digital data comprising a plurality of data streams each representing one of a standard definition television signal and a high definition television signal and encoded in such a manner that it may be decoded at full resolution to produce an image substantially without visible decoding artifacts or decoded at partial resolution to produce an image possibly including visible decoding artifacts. A decoder is coupled to the digital data source, and has a maximum decoding bandwidth less than that required to simultaneously decode two high definition television signals at full decoding resolution. A controller, is coupled to the decoder, for selecting two respective ones of the data streams responsive to user input, and if 4 both represent a high definition television signal, requesting user input for specifying one of the two respective data streams to decode at partial resolution.. A television receiver according to the present invention allows the user to select whether a signal desired for recording is decoded at partial resolution, or at full resolution. BRIEF DESCRIPTION OF THE/DRAWING FIGURE 1 is a block diagram of a portion of an HDTV receiver according to principles of the present invention; FIGURES 2a, 3a, 3b, 4a, 4b, 4c, 4d, 5a, 5b, 6a, 6b, and 6c are diagrams of a television video images which may be displayed on a display device in a television receiver illustrated in FIGURE 1; FIGURE 2b is a diagram of the layout of a remote control device which may be used in conjunction with a television receiver illustrated in FIGURE 1; DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 1 is a block diagram of a portion of an HDTV receiver according to principles\| of the present invention. In Figure 1, only those elements necessary for an understanding of the present invention are illustrated. One skilled in the art will understand that many other elements necessary in an HDTV receiver are not illustrated, and will understand what those elements are, how to design and implement them, and how those other elements are interconnected with the illustrated elements. In Figure 1, an input terminal 5 is coupled to a source (not shown) of digital data including a plurality of time multiplexed data streams, each representing a video signal. Some of these data streams may represent high-definition video images, while others may represent standard-definition video images. In the illustrated embodiment, the video signal data streams in the digital data are encoded using known MPEG encoding, although other encoding techniques may be used. Other data streams, representing other signals may also be included in this digital data. For example, one or more of the data s streams may contain data representing an audio signal corresponding to a video signal data stream, or representing a program guide containing information relating to the content of the respective television programs multiplexed within the digital data, all in a known manner. The digital data source (not shown) may be, for example, a satellite receiver, a cable receiver, a digital recorder playback output, or any source providing such a signal. Input terminal 5 is coupled to an input terminal of an MPEG video signal decoder 10. In Figure 1, the input terminal 5 is coupled to an input terminal of a data stream selector 98 within the MPEG decoder 10. An output terminal of the selector 98 is coupled to an input terminal of a variable length codeword decoder (VLD) 100. A first output terminal of the VLD 100 is coupled to a partial-resolution decoder 102. A second output terminal of the VLD 100 is coupled to an input terminal of a full resolution decoder 104. Respective output terminals of the partial resolution decoder 102 and the full resolution decoder 104 are coupled to corresponding input terminals of a switching circuit 106. A first output terminal of the switching circuit 106 is coupled to a display device 108. The display device 108 is integrated in the television receiver and is capable of displaying a high-definition video image. One skilled in the art will understand that a sample rate converter (not shown) may be required to generate high definition television signals for the HDTV display device 108. One skilled in the art will also understand that this output terminal of the switching circuit 106 may also be coupled to an output terminal of the television receiver, and, thus, made available to equipment external to the television receiver, such as a standalone video monitor. A second output terminal of the switching circuit 106 is coupled to a sample rate converter 110. An output terminal of the sample rate converter 110 produces a low resolution video signal suitable to be recorded on a standard VCR, and is coupled to an output terminal 15. In Figure 1, this signal is an NTSC format television signal, though other formats, such as PAL or SECAM, or any other such format may also be used. The output terminal 15 may be connected to a VCR (not shown) capable of recording the signal produced by the scan rate converter 110. 6 A controller 112 has lespective control output terminals coupled to corresponding control input terminals of the MPEG video decoder 10, the switching circuit 106 and the sample rate convener 110. More specifically, the controller 112 produces control signals for the internal circuits within these elements, such as for the data stream selector 98, VLD 100. the partial resolution decoder 102 and the full resolution decoder 104 in the MPEG video decoder 10. Other control signals may be generated by the controller 112 and supplied to other, non-illustrated, circuitry in the illustrated embodiment, all in a known manner. The controller 112 may also generate video image signals, and couple those image signals, through the switching circuit 106, to the display device 108. For example, such images may represent on-screen-displays (OSDs) for presenting information to the user, and requesting command information back from the user, also in a known manner. A user input terminal 25 receives data representing user command data. The user input terminal 25 may be coupled to a control panel (not shown) on the television receiver, including, for example, buttons for entering control information. The user input terminal 25 may also be coupled to a receiver (not shown) for receiving data from a remote control device (also not shown), also including buttons for entering control information, possibly similar to those on the receiver control panel (if any), and capable of being operated by a user from a remote location, such as across the room from the receiver, all in a known manner. In operation, the MPEG decoder 10 operates in a time multiplexed manner to simultaneously decode more than one video data stream from the MPEG digital data at input terminal 5, representing respective video signals, selected in response to a control signal from the controller 112. More specifically, the selector 98 operates to extract the selected data streams from the digital data and provide only those data streams to the variable length codeword decoder 100. The data in those data streams includes successive variable length codewords. As is known, the codewords represent, among other things, coefficients of spatially encoded discrete cosine transform (DCT) macroblocks each representing a small block of the image represented by that data stream. In a known MPEG embodiment, up to 64 coefficients represent each macroblock. The VLD 100 produces respective streams of DCT coefficients from the selected data streams. The DCT coefficients related to one of the 7 selected data streams are supplied to the full resolution decoder 104. while the DCT coefficients related to another one of the selected data streams are supplied to the partial resolution decoder 102, in response to a control signal from the controller ] 12. The full resolution decoder 104 processes all of these 64 coefficient codewords to reproduce a video signal representing the image. This results in a video signal having the maximum quality. The partial resolution decoder 102, however, processes only a fraction of these 64 coefficient codewords. For example, in a known embodiment, only 6 of the 64 coefficients are processed to regenerate each macroblock in the image. This results in an image missing some of the information which was transmitted to the receiver. Because transmitted information is missing from the reproduced image, artifacts may be present in the image, and those artifacts may be visible and objectionable. The switching circuit 106 couples the respective output terminals of the MPEG decoder 10, from the full resolution decoder 104 and the partial resolution decoder 102 respectively, to either the display device 108 or the sample rate converter 110, in response to control signals from the controller 112. The display device 108 displays the image represented by the video signal coupled to its input terminal, in a known manner. The sample rate converter 110 converts the data at its input terminal to a low resolution format video signal, such as an NTSC format signal, and supplies that signal to the output terminal 15, in a known manner. The controller. 112- includes a processor (not shown) which operates in accordance with a software program, in a known manner. The controller 112 is programmed to receive commands from the user input terminal 25 and generate appropriate control signals to configure the various circuits to which it is coupled to the desired states. The controller 112 further operates to produce signals representing OSDs to be displayed on the display device 108, all in a manner to be described in more detail below. The system illustrated in Figure 1 will support a high resolution video output signal (analog or digital) at one output terminal of the switching circuit 106 while concurrently providing a low resolution output video signal for display/record on an NTSC compatible J 8 device at the output terminal of the sample rate converter ] 10. The two output paths are independent so it is not required that the video signal at the low resolution output terminal be a resampled version of the video signal at the high resolution output terminal. That is, the switching circuit 106 may route any of the decoded pictures from the full resolution decoder 104 and the partial resolution decoder 102 to either of the two output terminals. The MPEG video decoder 10 has a limited bandwidth in operation which may be described in terms of the total number of rnacroblocks that may be decoded per second. This bandwidth is shared between the selected data streams in such a way that the MPEG video decoder 10 is effectively time-multiplexed between several source pictures. This MPEG video decoder 10 further includes known display processing (not shown) that will allow the independent scaling and overlay of all decoded pictures. This display processing is used to facilitate multi-picture display modes, including subimages such as PIP, POP and PIG (picture in picture, picture outside picture and picture in graphic). It is anticipated that the low resolution output terminal 15 from the television receiver illustrated in Figure 1 will be used to support NTSC recording of digital source material. Current VCRs may have multiple video input terminals. The user will typically navigate a menu system in the VCR to select one of the video input terminals for recording. In a digital system as illustrated in Figure 1, however, the desired video signal is typically carried by one of the plurality of MPEG encoded digital data streams, and must be extracted and decoded before being output to an analog video recorder. As such, part of the process of selecting a signal to record on a VCR must be located within the digital television receiver itself. The television receiver, therefore, must also include a user interface to allow a user to navigate and select from among the range of video signals supplied to the receiver that may be directed to the record output terminal 15, and thus to the record input terminal of the VCR. The remainder of this application will describe the user interface in the television receiver. Figures 2a, 3a, 3b, 4a, 4b, 4c, 4d, 5a, 5b, 6a, 6b and 6c are diagrams of television video images which may be displayed on a display device 108 in a television receiver illustrated in Figure 1, and Figure 2b is a diagram of the layout of a remote control device 130 9 which may be used in conjunction with a television receiver illustrated in Figure I. Referring to Figure 2a, under some conditions, the image 120 displayed on the display device 108 will be controlled by the controller ] 12 (of Figure 1) to include a banner display 122, meaning an overlay along one edge of the display screen 108, typically the top. in a known manner. In the illustrated embodiment, the banner display 122 includes the time, date and title of the program currently being displayed. In some configurations of the banner display 122, a 'quick record' icon 124 may be also displayed. Referring again to Figure 1, the controller 112 monitors the user input terminal 25 to detect user commands, also in a known manner. The user may invoke a record menu system in the television receiver by highlighting and selecting the 'quick record' icon 124 from the display banner 122 using e.g. the control panel on the television receiver or the remote control 130. To do this on the remote control 130, the user would press the directional buttons 132 on the remote control 130 until the 'quick record' icon 124 is highlighted, then press the select button 134. Alternatively, the user may invoke the record menu system by pushing the "record" button 136 on the remote control 130. The user may also invoke the record menu system by maneuvering through the receiver program guide menu system in a manner to be described in more detail below. When the record menu is invoked by any of these methods, the system will at first assume that the user wishes to record one of the programs that is currently being displayed on the display device 108. If only one program is currently displayed on the screen the record operation will begin for that program. The switching circuit 106 will be conditioned by the controller 112 to couple the video signal being supplied to the display device 108 to the sample rate converter 110 also. The sample rate converter 110 will convert the signal to an NTSC signal, which is supplied to the record output terminal 15. The currently displayed picture will, thus, be formatted for NTSC output. In addition, when possible the video recorder will be signaled by the television receiver to begin recording via the VCR remote control link. It is anticipated that the video signal supplied to the display device 108 will be decoded at full resolution by decoder 104. However, one skilled in the art will understand that the signal being supplied to the display device 108 could be either a high definition or JJf 10 standard definition video signal, and it could be either decoded at full resolution by the full resolution decoder 104 or at partial resolution by the partial resolution decoder 102. In Figure 2a, a second image 121, in PIP format, is illustrated in phantom in the bottom left hand corner of the display device 108. More than one such picture could be included in the image displayed on the display device 108. If more than one program image is currently displayed on the display device 108, e.g. main image 120 and PIP 121, then, when the record menu system is invoked in the manner described above, a visual cue on the display device 108 will highlight one of the displayed program images (120, 121) and a graphic will be created to inform the user which program will be recorded. The user then may confirm or cancel the recording operation. For example, in Figure 3a, a bold black box 126a is displayed around the main program video image 120 to indicate that it is the current selection for the record output terminal 15. An on-screen display of a confirmation box 128a is generated by the controller 112 (of Figure 1) and also displayed on the display device 108. In the illustrated embodiment, this confirmation box 128a includes the channel number, the program title, and a brief description of the main image 120 program. The OK button of the confirmation box 128a is shown as depressed in order to indicate that it is the default selection for the confirmation box 128a. That is, when the user presses the select button 134 on the remote control 130, the default selection is activated. If the user presses the select button 134 on the remote control 130, activating the OK button, thus, confirming this selection for recording, the video signal representing the main image 120 will be supplied to the sample rate converter 110, and recording will begin. If the user does not want to record the video displayed in the main program video image 120, then the directional keys 132 on the remote control 130 may be pressed. This will condition the controller 112 to make the arrow button the default selection, and to show the arrow button as depressed (not shown - but similar to the depressed OK button illustrated in confirmation box 128a). This, in turn, indicates that a different program is desired for recording. If the select button 134 on the remote control 130 is then pressed, the next program currently being displayed on the display device 108 will be highlighted. As illustrated 11 in Figure 3b. the PIP image 121 is selected, and a bold black box 126b is displayed around the PIP image 121. Similarly to Figure 3a, a confirmation box 128b is displayed, including the channel number, program title and brief description of the PIP image 121 program. If the user wishes to confirm that the PIP image 121 program is to be recorded, then the directional keys 132 on the remote control 130 are again pressed. The controller ] 12 in response makes the OK button the default selection, and generates the confirmation box 128b with the OK button depressed, as illustrated. If the user presses the select button 134 on the remote control 130, activating the OK button, and confirming this selection for recording, the video signal representing the PIP image 121 will be supplied to the sample rate converter 110, and recording will begin. On the other hand, if yet another displayed program (not illustrated in Figure 3) is desired, then the arrow button on the confirmation box 128b may be activated again, by pressing the select button 134 on the remote control 130, until the desired program is highlighted. Then the OK button is activated, as described above, to begin recording of the selected program. The order of navigating among the displayed programs may be flexible and may be chosen in a way that is consistent with other menu operations in the television receiver and that may be easily understood by the user. For example, video windows may be navigated in order from the top of the screen to the bottom, and from left to right. The top left corner of each video window may be used as its point of reference when creating the select order for the displayed windows. If two or more windows have the same point of reference, then the windows will be selected in top to bottom order according to their stacking in the overlay. A system with a more sophisticated controller 112 and remote control 130 combination may allow a user to directly indicate which of the displayed programs should be recorded, e.g. by pressing digit buttons 135. One skilled in the art will recognize that known Copy Generation Management System (CGMS) markers may be present in some of the received programs. These markers will be detected and recognized by known circuitry (not shown) in the television receiver. The controller 112 will receive a status signal (not shown) from the detection and recognition 12 circuitry indicating if such markers are present in a displayed program, thereby indicating that the program is not available for recording. When in the record menu system a graphical and/or text cue will be used to indicate those programs which are marked as not available for recording by such markers. For example, when moving the selection from one displayed program to another by activating the arrow button on the confirmation box (128a, 128b), those programs that are not available for record will be automatically skipped. Some systems, however, may allow for direct selection of a program window for recording, e.g. by pressing the number buttons 135 on the remote control 130. In this case, an attempt to select a program that is not available for record will trigger the display of an on-screen message, similar in form to the confirmation boxes 128a and 128b, that explains that the program may not be recorded. If the selected record program is a standard definition television signal, i.e. MPEG Main Profile, Main Level or less, then the MPEG decoder 10 will be conditioned by the controller 112 to decode the record program in full resolution, because there is enough decoder 10 bandwidth to simultaneously decode a standard definition and a high definition television program (for the display device 108, for example) at full resolution. If, however, the selected record program is a high definition television signal, then the MPEG decoder 10 will not have sufficient bandwidth to simultaneously decode both the selected record program and another high definition television program at full resolution. Typically the record program would be decoded at partial resolution. However, in some cases, a user may wish to record a program at NTSC resolution without the artifacts introduced by the partial resolution decoder 102. Referring to Figure 4, if the selected record program is a high definition television signal then the controller 112 will generate an OSD in a known manner in which the user will be prompted to select between decoding the record program using the full resolution decoder 104 or the partial resolution decoder 102, as illustrated in Figure 4a. If the user selects the full resolution decoder 104, then the user is informed that it is not possible for another high definition programs to be decoded and displayed while the record is in progress (because there is insufficient bandwidth in the MPEG video decoder 10), as illustrated in Figure 4b. If the user selects the partial resolution decoder 102, then the user is informed that there are no 13 restrictions on what other programs may be decoded and displayed while the recording is in progress, as illustrated in Figure 4c. Once all the appropriate selections have been made by the user, the selected program, decoded in the selected manner, is started. Referring to Figure 5a, after recording of the selected program is started, the user will be asked whether the user desires to record this program on a schedule. In the illustrated embodiment, the controller 112 generates an OSD banner 142 on the bottom of the screen which asks the user to press 'Select' to add this program to the record schedule. Referring to Figure 5b, if the user presses the select button 134 on the remote control 130, a record schedule menu 144 will be displayed under the control of the controller 112. Those fields that can be filled in based on information known about the selected program will be shown with the appropriate data already entered. The cursor will be placed in the field that allows a user to select the frequency of the record event. The user may then enter desired information using the remote control 130 in a known manner. The controller 112 receives this information, and generates an appropriate schedule entry containing the user-entered information. As described above, if a high definition television program is being decoded at full resolution for recording, then the user is restricted to standard definition television programs only for viewing on the display device 108. This restriction may be enforced in different ways. One, simple, approach would be for the controller 112 to condition the display device 108 to display a black screen when an attempt is made to display a high definition television program on the display device 108. The controller 112 may further generate an OSD, to be overlaid atop the black screen, with a message informing the user that the requested program is not available while recording is in progress. The OSD may also simply give the user the option to terminate the record session and change channels to display the desired program on the display device 108 (not shown). Alternatively, the OSD may give the user the option of continuing the record session, by switching to partial resolution decoding of the record program, and change channels to display the desired program on the display device 108, or continue the record session and ignore the channel change request, as illustrated in Figure 4d. Referring to Figure 4d, pressing the select button 134 in this context would condition the controller 112 to display 14 the confirmation box illustrated in Figure 4c. This confirmation box would allow the user to either confirm or cancel the channel change for display and resolution change for the record program, by appropriate pressing of the directional buttons 132 and the select button 134, in the manner described above. Alternatively, the user may manipulate the directional buttons 132 and select button 134 to continue the high resolution recording and ignore the channel change. In response, the controller 112 displays the confirmation box illustrated in Figure 4b, that again would allow the user to either confirm or cancel continuing the record session, by appropriate pressing of the directional buttons 132 and the select button 134. Another approach to enforce the MPEG video decoder 10 restrictions, described above, would be for the controller 112 to implement what will be termed in this application an intelligent channel scan. When the record output terminal 15 video signal is being generated from a high definition television signal using the full resolution decoder 104, the controller 112 would generate program guide listings (Figure 6a) from which all other channels broadcasting high definition television material would automatically be removed. Attempts by a user to directly enter the channel number, e.g. using the digit keys 135 on the remote control 130, for a channel that carries a high definition television signal would be detected by the controller 112, which would generate the above mentioned OSDs (Figures 4b, 4c and 4d) atop a black screen explaining that the requested channel is not available while recording is in progress. The same options would then be presented to cancel the record operation. If the high definition television program selected for recording had been previously scheduled for a future time (see Figure 5 and associated description), then a second high definition television program may be decoded by the full resolution decoder 104 and displayed on the display device 108 until the scheduled record start time arrives. However, if the end time of the high definition television program being viewed would overlap the recording start time for the scheduled record program, then the controller 112 will generate a warning banner (similar to 142), to be displayed e.g. across the bottom of the screen of the display device 108 in a known manner, stating that it will not be possible to continue viewing this program after the scheduled recording begins. If the currently displayed program is a high definition 15 television program, is being decoded in full resolution using the decoder 104, and does not carry information about its end time, then the controller 112 will generate such a warning banner automatically. It is further possible for the controller 112 to display the warning banner only after a user has displayed the channel on the display device 108 for some minimum time period. It is further possible for the controller to remove the banner from the display device 108 after a brief time, on the order of several seconds, or in response to the user pressing the clear button (not shown) on the remote control 130. In addition, the controller 112 may display a warning message in the top right corner of the display device 108 prior to the start of the recording, for example, around 1 minute before the starting time for recording. This displayed message also will offer the user the opportunity to enter the record menu and preempt the scheduled recording. The user also has the opportunity at any time to enter the record menu system to create, modify or delete scheduled recording events. This menu is accessed through the TV main menu and may be accessed by pressing the menu button 138 on the remote control 130. The controller 112, in response to detecting the press of the menu button 138 will display a menu with several entries on the display device 108, in a known manner. One of those entries will be "schedule". By appropriate pressing of the directional buttons 132 and the select button 134, the controller 112 will similarly display a "schedule" menu, with several entries. One of those entries will be "record". Again, by appropriate pressing of the directional buttons 132 and the select button 134, the controller 112 will display a recording scheduling display. This is identical to the recording scheduling display 144 illustrated in Figure 5b. By entering appropriate information in response to the prompts, all in a known manner, a program may be scheduled for future recording. As described above, one or more of the data streams in the digital data at the input terminal 5 may carry program guide information, including channel numbers, starting and ending times (or durations), names and brief descriptions of all the programs present in the digital data. Referring to Figure 1, this information may be extracted by the selector 98, and the data in those data streams provided to the controller 112. Referring to Figure 6a, this data 16 may be processed by the controller 112 to generate a tabular display of this information. The user may condition the controller 112 to show this table on the display device 108, and then may select programs to watch or record from the information in the displayed table on the display device 108 by manipulating the directional keys and select key on the remote control 130, all in a known manner. In Figure 6a, the television program "Six Million Dollar Man" has been selected by the user, and appears highlighted. In Figure 6a, the entry is highlighted by having a white background. One skilled in the art will understand that any method of highlighting may be used. The record menu may be invoked directly from the program guide display by selecting a program using the directional buttons 132, as described above, and then pressing the record button 136 on the remote control 130. As described above, when a program is selected for recording, the controller 112 generates an OSDs asking for confirmation, as illustrated in Figures 4a, 4b and/or 4c. When the program that is selected for record is scheduled to occur at some future time it may be necessary for the user to choose whether the program will be recorded using the full resolution (104) or partial resolution (102) decoder, as illustrated in Figure 4d. The illustrated system will support different on-screen program guide data streams. Some of the program guides provide information about the definition of the program, i.e. standard definition versus high definition. If the program guide indicates that the selected record program is a high definition television program, the user will be immediately prompted for a record resolution, as described in detail above. The user interface system described above is intended for use in a television program distribution system carrying high-definition television (HDTV) and standard definition video signals, and containing a decoder having a bandwidth in which more than one channel can be decoded simultaneously, subject to the maximum bandwidth of the decoder. In particular, if a user instructs such a distribution system to record a program on a standard-definition medium (e.g., VHS tape), and if the system requires that one of two high-definition format programs be decoded at a reduced resolution for simultaneous decoding, then the proposed invention allows the user to choose between two options for recording: either using full resolution 17 decoding for the record program and forbidding simultaneous decoding and display of any other high-definition television program, or using reduced resolution decoding for the record program, and permitting simultaneous decoding and display of other high-definition television programs 18 WE CLAIM 1. An unproved television receiver for selecting two data streams, comprising: a source of digital data comprising a plurality of data streams each representing one of a standard definition television signal and a high definition television signal and encoded in such a manner that the data streams may be decoded at full resolution to produce an image substantially without visible decoding artifacts or decoded at partial resolution to produce an image with visible decoding artifacts; a decoder (10) coupled to the digital data source, having a maximum decoding bandwidth less than that required to simultaneously decode two high definition television signals at full decoding resolution; and a controller (112), coupled to the decoder, for selecting two respective ones of the data streams responsive to user input, and if both represent a high definition television signal, requesting user input for specifying one of the two respective data streams to decode at partial resolution. 2. The receiver as claimed in claim 1 comprising a display device (108), capable of displaying images, under the control of the controller (112); Wherein the controller (112) conditions the display device to display a visual cue to indicate to the user one of the selected data streams and responds to user input to condition the decoder to decode the indicated data stream at partial resolution. 19 3. The receiver as claimed in claim 2 wherein the controller is responsive to user input to either specify the indicated data stream to be decoded at partial resolution or display a visual cue to indicate the other one of the selected data streams. 4. The receiver as claimed in clam 2 wherein the controller conditions the display device (108) to display respective images represented by the television signals in the selected data streams, and to generate the visual cue as a box around the image represented by the indicated data stream. 5. The receiver as claimed in claim 4 wherein the box is a black box. 6. The receiver as claimed in claim 2 wherein the controller conditions the display device to generate a confirmation image and requests confirmation from the user of the indicated data stream to be decoded at partial resolution. 7. The receiver as claimed in claim 2 wherein the controller conditions the display device to display at least a portion of a schedule of television signals in the plurality of data streams in the digital data, and to generate a visual cue by highlighting a location in the portion of the schedule of a television signals representing the indicating data stream and responds to user input to specify the indicated data stream to be decoded at partial resolution. 20 8. The receiver as claimed in claim 7 wherein the controller is responsive to user input to either highlight a different location in the portion of the schedule of a television signals to represent the indicated data stream or display a visual cue to indicate a different location in the portion of the schedule of television signals to represent the indicated data stream. 9. The receiver as claimed in claim 7 wherein the controller conditions the display device to display the visual cue as a tabular display of the schedule of television signals in which each signal occupies one entry in the table, and the entry for the indicated data stream is highlighted. 10.The receiver as claimed in claim 7 wherein the controller conditions the display device to generate a confirmation image and requests confirmation from the user of the indicated data stream to be decoded at partial resolution. 11.An improved television receiver for selecting two data streams, comprising: a source of digital data comprising a plurality of data streams each representing one of a standard definition television signal and a high definition television signal and encoded in such a manner that the data streams may be decoded at full resolution to produce an image substantially without visible decoding artifacts; a display device (108) capable of displaying images represented by decocted television signals; 21 a record signal output terminal (15) capable of producing a record video signal; a decoder, coupled between the digital data source and the display device and the record signal output terminal, having a maximum decoding bandwidth less than that required to simultaneously decode two high definition television signals at full decoding resolution; a controller (112) coupled to the decoder, for selecting two respective ones of the data streams responsive to user input, and if both represent a high definition television signal, requesting user input for specifying one of the two respective data streams to decode at partial resolution. 12.The receiver as claimed in claim 11, wherein the controller conditions the decoder to decode a first one of the selected data streams at full resolution to provide an image to the display device in response to user input. 13.The receiver as claimed in claim 11, wherein the controller conditions the decoder to simultaneously decode the second one of the selected data streams at partial resolution to provide an image to the display device in response to user input wherein the image represented by the first one of the selected data streams forms a main image, and the image represented by the second one of the selected data streams forms a sub image. 22 14.The receiver as claimed in claim 13, wherein the controller is responsive to user input to indicate one of the selected data streams, and provide a signal represented by the indicated data stream to the record signal output terminal. 15.The receiver as claimed in claim 14, wherein the controller conditions the display device to generate the visual cue as a box around the image represented by the indicated data stream. 16.The receiver as claimed in claim 15, wherein the box is a bold black box. 17.The receiver as claimed in claim 14, wherein the controller conditions the display device to display an image requesting input from the user whether to decode the indicated data stream at full resolution or partial resolution, and responsive to user input conditions the decoder to decode the indicated data stream at the resolution specified by the user input. 18.The receiver as claimed in claim 17, wherein the controller conditions the display device to display an image indicating the specified resolution, and requesting confirming user input. 19.The receiver as claimed in claim 17, wherein if the user input specifies the indicated data stream should be decoded at full resolution, the controller conditions the decoder to decode the indicated data stream at full resolution and supplies the television signal represented by the decoded indicated data stream to the record signal output terminal, and restricts data streams representing high definition television programs from being displayed on the display device. 23 20.The receiver as claimed in claim 19, wherein if the other one of the selected data streams represents a high definition television signal, the controller conditions the decoder to decode the other one of the selected data streams at partial resolution. 21.The receiver as claimed in claim 19, wherein the controller is responsive to user input to ignore requests that a high definition television signal be displayed on the display device. 22.The receiver as claimed in claim 19, wherein if the controller receives user input requesting that a high definition television signal be displayed on the display device, the controller conditions the display device to display an image that it is not permitted. 23.The receiver as claimed in claim 22, wherein the controller conditions the display device to display an image which is a black screen. 24.The receiver as claimed in claim 23, wherein the controller conditions the display device to display an image which additionally comprises information informing the user that the decoder is currently decoding a data stream at full resolution for the record signal terminal displayed atop the black screen. 25.The receiver as claimed in claim 24, wherein the controller additionally conditions the display device to display an image requesting user input to determine whether to stop decoding a data stream at full resolution for the record signal output terminal and display the requested high definition television signal on the display device; and 24 if user input specifies that decoding of the data stream at full resolution for the record signal output terminal is to stop, the controller conditions the decoder to decode the high definition television signal for the display device at partial resolution, and simultaneously decode the requested television at full resolution for display device. 26.The receiver as claimed in claim 25, wherein the controller conditions the display device to display an image requesting confirmation of the requested user input. Dated this 29th day of April, 2002 OF L.S. DAVAR & CO. APPLICANTS' AGENT This invention relates to an improved television receiver for selecting two data streams, a source of digital data comprising a plurality of data streams each representing one of a standard definition television signal and a high definition television signal and encoded in such a manner that the data streams may be decoded at full resolution to produce an image substantially without visible decoding artifacts or decoded at partial resolution to produce an image with visible decoding artifacts; a decoder (10) coupled to the digital data source, having a maximum decoding bandwidth less than that required to simultaneously decode two high definition television signals at full decoding resolution; and a controller (112), coupled to the decoder, for selecting two respective ones of the data streams responsive to user input, and if both represent a high definition television signal, requesting user input for specifying one of the two respective data streams to decode at partial resolution.

Full Text

Field of the Invention.
The present invention relates to a system and user interface for processing
digital data, containing a plurality of time multiplexed data streams, some of which represent
video signals, and in particular coded high-definition (HD) video signals, to derive a decoded
video signal suitable, for example, for recording or producing a picture-in-picture (PEP) or
other reduced resolution purposes.
Description of the Prior Art:
Television receivers are known that, while displaying a relatively large picture derived
from a primary television channel, also can simultaneously display a small subimage such as a
picture-in-picture (PIP) derived from a secondary television channel. For high-definition
television (HDTV) receivers, the large picture may be derived from a high-definition source,
and be displayed with a corresponding high visual resolution. However, because the PEP is
small, there is no need to provide a high definition PIP display because a viewer inherently
would not be able to resolve the higher definition components of a high definition PEP.
Viewers also sometimes desire to record television signals. Standard analog video cassette
recorders (VCRs) cannot record HDTV signals at their full resolution. Therefore, before a
HDTV channel may be recorded on a standard VCR, it must be transformed into a lower
resolution e.g. NTSC format video signal. This lower resolution signal may then be supplied
to the VCR.
In a digital television signal distribution system, a plurality of digital data streams, each
representing a respective video signal, are time multiplexed together and transmitted to the
receiver, in a known manner. The digital data in each of the plurality of data streams is

encoded and highly compressed according to known encoding schemes, such as MPEG
encoding, and must be decoded to regenerate any of the video signals represented by it.
Known HDTV receivers include a relatively complex and expensive decoder that conforms
with the ISO 1 3818-2 standard for decoding a received coded HD video signal in real time to
generate a high-definition video signal for the high definition display device in the receiver.
This decoder uses all of the transmitted data in the data stream representing that video signal
to reproduce the high-definition video signal representing the transmitted image. However, as
described above, a lower resolution video signal is generated for a PIP and/or VCR. This
process involves two steps. First, the digital data stream is decoded into a video signal
represented by that data stream. Second, this video signal is sample-rate-converted to the
lower resolution, e.g. NTSC, video format.
To provide the PIP and/or VCR video signal, known HDTV receivers also include a
second, lower-resolution, simpler and less expensive, decoder which also conforms with the
ISO 13818-2 standard. This decoder, however, uses only a portion of the transmitted data in
the data stream representing that video signal to reproduce a low-definition video signal
representing the transmitted image. Consequently, this video signal possibly represents an
image which contains visible and objectionable artifacts. For a PIP image, this is not a
problem, because the small size of the PIP image makes such artifacts practically invisible to
the viewer. However, an image to be recorded and played-back will most likely be displayed
at full size, allowing these artifacts to remain visible, and possibly objectionable. If a high-
definition TV program is selected to record, a choice exists for how to produce the low-
resolution video signal. First, the high definition video data may be first decoded using the
low resolution decoder. This produces a low resolution video signal having artifacts, as
described above. This low-resolution signal is then scan-rate-converted into the low
resolution, e.g. NTSC, format. Alternatively, the high resolution data may be first decoded
using the high resolution decoder. This produces a high resolution video signal free of
artifacts. This high resolution signal is then scan-rate-converted into the low resolution, e.g.
NTSC, format.

3
A receiver including nvo decoders is relatively expensive. Further developments have
led to an arrangement in which a single decoder was able to be "shared" by two video data
streams. Such a decoder was developed which was time multiplexed to be able to decode
multiple data streams from the time multiplexed data stream. Such a decoder produces two
output signals independently, representing two of the plurality of video signals in the data
stream. However, a practical single decoder may not be constructed in an economical manner
to simultaneously decode two HDTV signals. Instead, such a decoder may decode a single
HDTV signal, and a second signal decoded at lower resolution.
A number of problems arise in providing a User interface suitable for operation of an
HDTV (or other digital TV) receiver employing decoder units capable of simultaneously
processing multiple images for display and/or recording. Such problems arise because of the
increased number of processing options available to a User, bandwidth constraints of the
decoder, and different system and peripheral configurations (e.g. different storage and
playback units) that may be used in an HDTV entertainment system. These problems and
derivative problems are addressed by a system according to the present invention.
SUMMARY OF THE INVENTION
In accordance with principles of the present invention a television receiver includes a
source of digital data comprising a plurality of data streams each representing one of a
standard definition television signal and a high definition television signal and encoded in such
a manner that it may be decoded at full resolution to produce an image substantially without
visible decoding artifacts or decoded at partial resolution to produce an image possibly
including visible decoding artifacts. A decoder is coupled to the digital data source, and has a
maximum decoding bandwidth less than that required to simultaneously decode two high
definition television signals at full decoding resolution. A controller, is coupled to the
decoder, for selecting two respective ones of the data streams responsive to user input, and if

4
both represent a high definition television signal, requesting user input for specifying one of
the two respective data streams to decode at partial resolution..
A television receiver according to the present invention allows the user to select
whether a signal desired for recording is decoded at partial resolution, or at full resolution.
BRIEF DESCRIPTION OF THE/DRAWING
FIGURE 1 is a block diagram of a portion of an HDTV receiver according to
principles of the present invention;
FIGURES 2a, 3a, 3b, 4a, 4b, 4c, 4d, 5a, 5b, 6a, 6b, and 6c are diagrams of a television
video images which may be displayed on a display device in a television receiver illustrated in
FIGURE 1;
FIGURE 2b is a diagram of the layout of a remote control device which may be used
in conjunction with a television receiver illustrated in FIGURE 1;
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Figure 1 is a block diagram of a portion of an HDTV receiver according to principles|
of the present invention. In Figure 1, only those elements necessary for an understanding of
the present invention are illustrated. One skilled in the art will understand that many other
elements necessary in an HDTV receiver are not illustrated, and will understand what those
elements are, how to design and implement them, and how those other elements are
interconnected with the illustrated elements. In Figure 1, an input terminal 5 is coupled to a
source (not shown) of digital data including a plurality of time multiplexed data streams, each
representing a video signal. Some of these data streams may represent high-definition video
images, while others may represent standard-definition video images. In the illustrated
embodiment, the video signal data streams in the digital data are encoded using known MPEG
encoding, although other encoding techniques may be used. Other data streams, representing
other signals may also be included in this digital data. For example, one or more of the data

s
streams may contain data representing an audio signal corresponding to a video signal data
stream, or representing a program guide containing information relating to the content of the
respective television programs multiplexed within the digital data, all in a known manner. The
digital data source (not shown) may be, for example, a satellite receiver, a cable receiver, a
digital recorder playback output, or any source providing such a signal.
Input terminal 5 is coupled to an input terminal of an MPEG video signal decoder 10.
In Figure 1, the input terminal 5 is coupled to an input terminal of a data stream selector 98
within the MPEG decoder 10. An output terminal of the selector 98 is coupled to an input
terminal of a variable length codeword decoder (VLD) 100. A first output terminal of the
VLD 100 is coupled to a partial-resolution decoder 102. A second output terminal of the
VLD 100 is coupled to an input terminal of a full resolution decoder 104. Respective output
terminals of the partial resolution decoder 102 and the full resolution decoder 104 are coupled
to corresponding input terminals of a switching circuit 106. A first output terminal of the
switching circuit 106 is coupled to a display device 108. The display device 108 is integrated
in the television receiver and is capable of displaying a high-definition video image. One
skilled in the art will understand that a sample rate converter (not shown) may be required to
generate high definition television signals for the HDTV display device 108. One skilled in the
art will also understand that this output terminal of the switching circuit 106 may also be
coupled to an output terminal of the television receiver, and, thus, made available to
equipment external to the television receiver, such as a standalone video monitor.
A second output terminal of the switching circuit 106 is coupled to a sample rate
converter 110. An output terminal of the sample rate converter 110 produces a low resolution
video signal suitable to be recorded on a standard VCR, and is coupled to an output terminal
15. In Figure 1, this signal is an NTSC format television signal, though other formats, such as
PAL or SECAM, or any other such format may also be used. The output terminal 15 may be
connected to a VCR (not shown) capable of recording the signal produced by the scan rate
converter 110.

6
A controller 112 has lespective control output terminals coupled to corresponding
control input terminals of the MPEG video decoder 10, the switching circuit 106 and the
sample rate convener 110. More specifically, the controller 112 produces control signals for
the internal circuits within these elements, such as for the data stream selector 98, VLD 100.
the partial resolution decoder 102 and the full resolution decoder 104 in the MPEG video
decoder 10. Other control signals may be generated by the controller 112 and supplied to
other, non-illustrated, circuitry in the illustrated embodiment, all in a known manner. The
controller 112 may also generate video image signals, and couple those image signals, through
the switching circuit 106, to the display device 108. For example, such images may represent
on-screen-displays (OSDs) for presenting information to the user, and requesting command
information back from the user, also in a known manner. A user input terminal 25 receives
data representing user command data. The user input terminal 25 may be coupled to a control
panel (not shown) on the television receiver, including, for example, buttons for entering
control information. The user input terminal 25 may also be coupled to a receiver (not shown)
for receiving data from a remote control device (also not shown), also including buttons for
entering control information, possibly similar to those on the receiver control panel (if any),
and capable of being operated by a user from a remote location, such as across the room from
the receiver, all in a known manner.
In operation, the MPEG decoder 10 operates in a time multiplexed manner to
simultaneously decode more than one video data stream from the MPEG digital data at input
terminal 5, representing respective video signals, selected in response to a control signal from
the controller 112. More specifically, the selector 98 operates to extract the selected data
streams from the digital data and provide only those data streams to the variable length
codeword decoder 100. The data in those data streams includes successive variable length
codewords. As is known, the codewords represent, among other things, coefficients of
spatially encoded discrete cosine transform (DCT) macroblocks each representing a small
block of the image represented by that data stream. In a known MPEG embodiment, up to 64
coefficients represent each macroblock. The VLD 100 produces respective streams of DCT
coefficients from the selected data streams. The DCT coefficients related to one of the

7
selected data streams are supplied to the full resolution decoder 104. while the DCT
coefficients related to another one of the selected data streams are supplied to the partial
resolution decoder 102, in response to a control signal from the controller ] 12. The full
resolution decoder 104 processes all of these 64 coefficient codewords to reproduce a video
signal representing the image. This results in a video signal having the maximum quality. The
partial resolution decoder 102, however, processes only a fraction of these 64 coefficient
codewords. For example, in a known embodiment, only 6 of the 64 coefficients are processed
to regenerate each macroblock in the image. This results in an image missing some of the
information which was transmitted to the receiver. Because transmitted information is missing
from the reproduced image, artifacts may be present in the image, and those artifacts may be
visible and objectionable.
The switching circuit 106 couples the respective output terminals of the MPEG
decoder 10, from the full resolution decoder 104 and the partial resolution decoder 102
respectively, to either the display device 108 or the sample rate converter 110, in response to
control signals from the controller 112. The display device 108 displays the image represented
by the video signal coupled to its input terminal, in a known manner. The sample rate
converter 110 converts the data at its input terminal to a low resolution format video signal,
such as an NTSC format signal, and supplies that signal to the output terminal 15, in a known
manner.
The controller. 112- includes a processor (not shown) which operates in accordance
with a software program, in a known manner. The controller 112 is programmed to receive
commands from the user input terminal 25 and generate appropriate control signals to
configure the various circuits to which it is coupled to the desired states. The controller 112
further operates to produce signals representing OSDs to be displayed on the display device
108, all in a manner to be described in more detail below.
The system illustrated in Figure 1 will support a high resolution video output signal
(analog or digital) at one output terminal of the switching circuit 106 while concurrently
providing a low resolution output video signal for display/record on an NTSC compatible J

8
device at the output terminal of the sample rate converter ] 10. The two output paths are
independent so it is not required that the video signal at the low resolution output terminal be
a resampled version of the video signal at the high resolution output terminal. That is, the
switching circuit 106 may route any of the decoded pictures from the full resolution decoder
104 and the partial resolution decoder 102 to either of the two output terminals.
The MPEG video decoder 10 has a limited bandwidth in operation which may be
described in terms of the total number of rnacroblocks that may be decoded per second. This
bandwidth is shared between the selected data streams in such a way that the MPEG video
decoder 10 is effectively time-multiplexed between several source pictures. This MPEG video
decoder 10 further includes known display processing (not shown) that will allow the
independent scaling and overlay of all decoded pictures. This display processing is used to
facilitate multi-picture display modes, including subimages such as PIP, POP and PIG (picture
in picture, picture outside picture and picture in graphic).
It is anticipated that the low resolution output terminal 15 from the television receiver
illustrated in Figure 1 will be used to support NTSC recording of digital source material.
Current VCRs may have multiple video input terminals. The user will typically navigate a
menu system in the VCR to select one of the video input terminals for recording. In a digital
system as illustrated in Figure 1, however, the desired video signal is typically carried by one
of the plurality of MPEG encoded digital data streams, and must be extracted and decoded
before being output to an analog video recorder. As such, part of the process of selecting a
signal to record on a VCR must be located within the digital television receiver itself. The
television receiver, therefore, must also include a user interface to allow a user to navigate and
select from among the range of video signals supplied to the receiver that may be directed to
the record output terminal 15, and thus to the record input terminal of the VCR. The
remainder of this application will describe the user interface in the television receiver.
Figures 2a, 3a, 3b, 4a, 4b, 4c, 4d, 5a, 5b, 6a, 6b and 6c are diagrams of television
video images which may be displayed on a display device 108 in a television receiver
illustrated in Figure 1, and Figure 2b is a diagram of the layout of a remote control device 130

9
which may be used in conjunction with a television receiver illustrated in Figure I. Referring
to Figure 2a, under some conditions, the image 120 displayed on the display device 108 will
be controlled by the controller ] 12 (of Figure 1) to include a banner display 122, meaning an
overlay along one edge of the display screen 108, typically the top. in a known manner. In the
illustrated embodiment, the banner display 122 includes the time, date and title of the program
currently being displayed. In some configurations of the banner display 122, a 'quick record'
icon 124 may be also displayed. Referring again to Figure 1, the controller 112 monitors the
user input terminal 25 to detect user commands, also in a known manner.
The user may invoke a record menu system in the television receiver by highlighting
and selecting the 'quick record' icon 124 from the display banner 122 using e.g. the control
panel on the television receiver or the remote control 130. To do this on the remote control
130, the user would press the directional buttons 132 on the remote control 130 until the
'quick record' icon 124 is highlighted, then press the select button 134. Alternatively, the user
may invoke the record menu system by pushing the "record" button 136 on the remote control
130. The user may also invoke the record menu system by maneuvering through the receiver
program guide menu system in a manner to be described in more detail below.
When the record menu is invoked by any of these methods, the system will at first
assume that the user wishes to record one of the programs that is currently being displayed on
the display device 108. If only one program is currently displayed on the screen the record
operation will begin for that program. The switching circuit 106 will be conditioned by the
controller 112 to couple the video signal being supplied to the display device 108 to the
sample rate converter 110 also. The sample rate converter 110 will convert the signal to an
NTSC signal, which is supplied to the record output terminal 15. The currently displayed
picture will, thus, be formatted for NTSC output. In addition, when possible the video
recorder will be signaled by the television receiver to begin recording via the VCR remote
control link. It is anticipated that the video signal supplied to the display device 108 will be
decoded at full resolution by decoder 104. However, one skilled in the art will understand
that the signal being supplied to the display device 108 could be either a high definition or JJf

10
standard definition video signal, and it could be either decoded at full resolution by the full
resolution decoder 104 or at partial resolution by the partial resolution decoder 102.
In Figure 2a, a second image 121, in PIP format, is illustrated in phantom in the
bottom left hand corner of the display device 108. More than one such picture could be
included in the image displayed on the display device 108. If more than one program image is
currently displayed on the display device 108, e.g. main image 120 and PIP 121, then, when
the record menu system is invoked in the manner described above, a visual cue on the display
device 108 will highlight one of the displayed program images (120, 121) and a graphic will be
created to inform the user which program will be recorded. The user then may confirm or
cancel the recording operation. For example, in Figure 3a, a bold black box 126a is displayed
around the main program video image 120 to indicate that it is the current selection for the
record output terminal 15. An on-screen display of a confirmation box 128a is generated by
the controller 112 (of Figure 1) and also displayed on the display device 108. In the illustrated
embodiment, this confirmation box 128a includes the channel number, the program title, and a
brief description of the main image 120 program. The OK button of the confirmation box 128a
is shown as depressed in order to indicate that it is the default selection for the confirmation
box 128a. That is, when the user presses the select button 134 on the remote control 130, the
default selection is activated. If the user presses the select button 134 on the remote control
130, activating the OK button, thus, confirming this selection for recording, the video signal
representing the main image 120 will be supplied to the sample rate converter 110, and
recording will begin.
If the user does not want to record the video displayed in the main program video
image 120, then the directional keys 132 on the remote control 130 may be pressed. This will
condition the controller 112 to make the arrow button the default selection, and to show the
arrow button as depressed (not shown - but similar to the depressed OK button illustrated in
confirmation box 128a). This, in turn, indicates that a different program is desired for
recording. If the select button 134 on the remote control 130 is then pressed, the next
program currently being displayed on the display device 108 will be highlighted. As illustrated

11
in Figure 3b. the PIP image 121 is selected, and a bold black box 126b is displayed around the
PIP image 121. Similarly to Figure 3a, a confirmation box 128b is displayed, including the
channel number, program title and brief description of the PIP image 121 program. If the user
wishes to confirm that the PIP image 121 program is to be recorded, then the directional keys
132 on the remote control 130 are again pressed. The controller ] 12 in response makes the
OK button the default selection, and generates the confirmation box 128b with the OK button
depressed, as illustrated. If the user presses the select button 134 on the remote control 130,
activating the OK button, and confirming this selection for recording, the video signal
representing the PIP image 121 will be supplied to the sample rate converter 110, and
recording will begin. On the other hand, if yet another displayed program (not illustrated in
Figure 3) is desired, then the arrow button on the confirmation box 128b may be activated
again, by pressing the select button 134 on the remote control 130, until the desired program
is highlighted. Then the OK button is activated, as described above, to begin recording of the
selected program.
The order of navigating among the displayed programs may be flexible and may be
chosen in a way that is consistent with other menu operations in the television receiver and
that may be easily understood by the user. For example, video windows may be navigated in
order from the top of the screen to the bottom, and from left to right. The top left corner of
each video window may be used as its point of reference when creating the select order for the
displayed windows. If two or more windows have the same point of reference, then the
windows will be selected in top to bottom order according to their stacking in the overlay. A
system with a more sophisticated controller 112 and remote control 130 combination may
allow a user to directly indicate which of the displayed programs should be recorded, e.g. by
pressing digit buttons 135.
One skilled in the art will recognize that known Copy Generation Management System
(CGMS) markers may be present in some of the received programs. These markers will be
detected and recognized by known circuitry (not shown) in the television receiver. The
controller 112 will receive a status signal (not shown) from the detection and recognition

12
circuitry indicating if such markers are present in a displayed program, thereby indicating that
the program is not available for recording. When in the record menu system a graphical
and/or text cue will be used to indicate those programs which are marked as not available for
recording by such markers. For example, when moving the selection from one displayed
program to another by activating the arrow button on the confirmation box (128a, 128b),
those programs that are not available for record will be automatically skipped. Some systems,
however, may allow for direct selection of a program window for recording, e.g. by pressing
the number buttons 135 on the remote control 130. In this case, an attempt to select a
program that is not available for record will trigger the display of an on-screen message,
similar in form to the confirmation boxes 128a and 128b, that explains that the program may
not be recorded.
If the selected record program is a standard definition television signal, i.e. MPEG
Main Profile, Main Level or less, then the MPEG decoder 10 will be conditioned by the
controller 112 to decode the record program in full resolution, because there is enough
decoder 10 bandwidth to simultaneously decode a standard definition and a high definition
television program (for the display device 108, for example) at full resolution. If, however,
the selected record program is a high definition television signal, then the MPEG decoder 10
will not have sufficient bandwidth to simultaneously decode both the selected record program
and another high definition television program at full resolution. Typically the record program
would be decoded at partial resolution. However, in some cases, a user may wish to record a
program at NTSC resolution without the artifacts introduced by the partial resolution decoder
102. Referring to Figure 4, if the selected record program is a high definition television signal
then the controller 112 will generate an OSD in a known manner in which the user will be
prompted to select between decoding the record program using the full resolution decoder
104 or the partial resolution decoder 102, as illustrated in Figure 4a. If the user selects the full
resolution decoder 104, then the user is informed that it is not possible for another high
definition programs to be decoded and displayed while the record is in progress (because there
is insufficient bandwidth in the MPEG video decoder 10), as illustrated in Figure 4b. If the
user selects the partial resolution decoder 102, then the user is informed that there are no

13
restrictions on what other programs may be decoded and displayed while the recording is in
progress, as illustrated in Figure 4c. Once all the appropriate selections have been made by
the user, the selected program, decoded in the selected manner, is started.
Referring to Figure 5a, after recording of the selected program is started, the user will
be asked whether the user desires to record this program on a schedule. In the illustrated
embodiment, the controller 112 generates an OSD banner 142 on the bottom of the screen
which asks the user to press 'Select' to add this program to the record schedule. Referring to
Figure 5b, if the user presses the select button 134 on the remote control 130, a record
schedule menu 144 will be displayed under the control of the controller 112. Those fields that
can be filled in based on information known about the selected program will be shown with the
appropriate data already entered. The cursor will be placed in the field that allows a user to
select the frequency of the record event. The user may then enter desired information using
the remote control 130 in a known manner. The controller 112 receives this information, and
generates an appropriate schedule entry containing the user-entered information.
As described above, if a high definition television program is being decoded at full
resolution for recording, then the user is restricted to standard definition television programs
only for viewing on the display device 108. This restriction may be enforced in different ways.
One, simple, approach would be for the controller 112 to condition the display device 108 to
display a black screen when an attempt is made to display a high definition television program
on the display device 108. The controller 112 may further generate an OSD, to be overlaid
atop the black screen, with a message informing the user that the requested program is not
available while recording is in progress. The OSD may also simply give the user the option to
terminate the record session and change channels to display the desired program on the display
device 108 (not shown). Alternatively, the OSD may give the user the option of continuing the
record session, by switching to partial resolution decoding of the record program, and change
channels to display the desired program on the display device 108, or continue the record
session and ignore the channel change request, as illustrated in Figure 4d. Referring to Figure
4d, pressing the select button 134 in this context would condition the controller 112 to display

14
the confirmation box illustrated in Figure 4c. This confirmation box would allow the user to
either confirm or cancel the channel change for display and resolution change for the record
program, by appropriate pressing of the directional buttons 132 and the select button 134, in
the manner described above. Alternatively, the user may manipulate the directional buttons
132 and select button 134 to continue the high resolution recording and ignore the channel
change. In response, the controller 112 displays the confirmation box illustrated in Figure 4b,
that again would allow the user to either confirm or cancel continuing the record session, by
appropriate pressing of the directional buttons 132 and the select button 134.
Another approach to enforce the MPEG video decoder 10 restrictions, described
above, would be for the controller 112 to implement what will be termed in this application an
intelligent channel scan. When the record output terminal 15 video signal is being generated
from a high definition television signal using the full resolution decoder 104, the controller 112
would generate program guide listings (Figure 6a) from which all other channels broadcasting
high definition television material would automatically be removed. Attempts by a user to
directly enter the channel number, e.g. using the digit keys 135 on the remote control 130, for
a channel that carries a high definition television signal would be detected by the controller
112, which would generate the above mentioned OSDs (Figures 4b, 4c and 4d) atop a black
screen explaining that the requested channel is not available while recording is in progress.
The same options would then be presented to cancel the record operation.
If the high definition television program selected for recording had been previously
scheduled for a future time (see Figure 5 and associated description), then a second high
definition television program may be decoded by the full resolution decoder 104 and displayed
on the display device 108 until the scheduled record start time arrives. However, if the end
time of the high definition television program being viewed would overlap the recording start
time for the scheduled record program, then the controller 112 will generate a warning banner
(similar to 142), to be displayed e.g. across the bottom of the screen of the display device 108
in a known manner, stating that it will not be possible to continue viewing this program after
the scheduled recording begins. If the currently displayed program is a high definition

15
television program, is being decoded in full resolution using the decoder 104, and does not
carry information about its end time, then the controller 112 will generate such a warning
banner automatically. It is further possible for the controller 112 to display the warning
banner only after a user has displayed the channel on the display device 108 for some
minimum time period. It is further possible for the controller to remove the banner from the
display device 108 after a brief time, on the order of several seconds, or in response to the
user pressing the clear button (not shown) on the remote control 130. In addition, the
controller 112 may display a warning message in the top right corner of the display device 108
prior to the start of the recording, for example, around 1 minute before the starting time for
recording. This displayed message also will offer the user the opportunity to enter the record
menu and preempt the scheduled recording.
The user also has the opportunity at any time to enter the record menu system to
create, modify or delete scheduled recording events. This menu is accessed through the TV
main menu and may be accessed by pressing the menu button 138 on the remote control 130.
The controller 112, in response to detecting the press of the menu button 138 will display a
menu with several entries on the display device 108, in a known manner. One of those entries
will be "schedule". By appropriate pressing of the directional buttons 132 and the select
button 134, the controller 112 will similarly display a "schedule" menu, with several entries.
One of those entries will be "record". Again, by appropriate pressing of the directional
buttons 132 and the select button 134, the controller 112 will display a recording scheduling
display. This is identical to the recording scheduling display 144 illustrated in Figure 5b. By
entering appropriate information in response to the prompts, all in a known manner, a program
may be scheduled for future recording.
As described above, one or more of the data streams in the digital data at the input
terminal 5 may carry program guide information, including channel numbers, starting and
ending times (or durations), names and brief descriptions of all the programs present in the
digital data. Referring to Figure 1, this information may be extracted by the selector 98, and
the data in those data streams provided to the controller 112. Referring to Figure 6a, this data

16
may be processed by the controller 112 to generate a tabular display of this information. The
user may condition the controller 112 to show this table on the display device 108, and then
may select programs to watch or record from the information in the displayed table on the
display device 108 by manipulating the directional keys and select key on the remote control
130, all in a known manner. In Figure 6a, the television program "Six Million Dollar Man"
has been selected by the user, and appears highlighted. In Figure 6a, the entry is highlighted
by having a white background. One skilled in the art will understand that any method of
highlighting may be used.
The record menu may be invoked directly from the program guide display by selecting
a program using the directional buttons 132, as described above, and then pressing the record
button 136 on the remote control 130. As described above, when a program is selected for
recording, the controller 112 generates an OSDs asking for confirmation, as illustrated in
Figures 4a, 4b and/or 4c. When the program that is selected for record is scheduled to occur
at some future time it may be necessary for the user to choose whether the program will be
recorded using the full resolution (104) or partial resolution (102) decoder, as illustrated in
Figure 4d. The illustrated system will support different on-screen program guide data streams.
Some of the program guides provide information about the definition of the program, i.e.
standard definition versus high definition. If the program guide indicates that the selected
record program is a high definition television program, the user will be immediately prompted
for a record resolution, as described in detail above.
The user interface system described above is intended for use in a television program
distribution system carrying high-definition television (HDTV) and standard definition video
signals, and containing a decoder having a bandwidth in which more than one channel can be
decoded simultaneously, subject to the maximum bandwidth of the decoder. In particular, if a
user instructs such a distribution system to record a program on a standard-definition medium
(e.g., VHS tape), and if the system requires that one of two high-definition format programs
be decoded at a reduced resolution for simultaneous decoding, then the proposed invention
allows the user to choose between two options for recording: either using full resolution

17
decoding for the record program and forbidding simultaneous decoding and display of any
other high-definition television program, or using reduced resolution decoding for the record
program, and permitting simultaneous decoding and display of other high-definition television
programs

18
WE CLAIM
1. An unproved television receiver for selecting two data streams,
comprising:
a source of digital data comprising a plurality of data streams each
representing one of a standard definition television signal and a high
definition television signal and encoded in such a manner that the data
streams may be decoded at full resolution to produce an image
substantially without visible decoding artifacts or decoded at partial
resolution to produce an image with visible decoding artifacts;
a decoder (10) coupled to the digital data source, having a maximum
decoding bandwidth less than that required to simultaneously decode two
high definition television signals at full decoding resolution; and
a controller (112), coupled to the decoder, for selecting two respective
ones of the data streams responsive to user input, and if both represent a
high definition television signal, requesting user input for specifying one of
the two respective data streams to decode at partial resolution.
2. The receiver as claimed in claim 1 comprising a display device (108),
capable of displaying images, under the control of the controller (112);
Wherein the controller (112) conditions the display device to display a
visual cue to indicate to the user one of the selected data streams and
responds to user input to condition the decoder to decode the indicated
data stream at partial resolution.

19
3. The receiver as claimed in claim 2 wherein the controller is responsive to
user input to either specify the indicated data stream to be decoded at
partial resolution or display a visual cue to indicate the other one of the
selected data streams.
4. The receiver as claimed in clam 2 wherein the controller conditions the
display device (108) to display respective images represented by the
television signals in the selected data streams, and to generate the visual
cue as a box around the image represented by the indicated data stream.
5. The receiver as claimed in claim 4 wherein the box is a black box.
6. The receiver as claimed in claim 2 wherein the controller conditions the
display device to generate a confirmation image and requests
confirmation from the user of the indicated data stream to be decoded at
partial resolution.
7. The receiver as claimed in claim 2 wherein the controller conditions the
display device to display at least a portion of a schedule of television
signals in the plurality of data streams in the digital data, and to generate
a visual cue by highlighting a location in the portion of the schedule of a
television signals representing the indicating data stream and responds to
user input to specify the indicated data stream to be decoded at partial
resolution.

20
8. The receiver as claimed in claim 7 wherein the controller is responsive to
user input to either highlight a different location in the portion of the
schedule of a television signals to represent the indicated data stream or
display a visual cue to indicate a different location in the portion of the
schedule of television signals to represent the indicated data stream.
9. The receiver as claimed in claim 7 wherein the controller conditions the
display device to display the visual cue as a tabular display of the schedule
of television signals in which each signal occupies one entry in the table,
and the entry for the indicated data stream is highlighted.
10.The receiver as claimed in claim 7 wherein the controller conditions the
display device to generate a confirmation image and requests
confirmation from the user of the indicated data stream to be decoded at
partial resolution.
11.An improved television receiver for selecting two data streams,
comprising:
a source of digital data comprising a plurality of data streams each
representing one of a standard definition television signal and a high
definition television signal and encoded in such a manner that the data
streams may be decoded at full resolution to produce an image
substantially without visible decoding artifacts;
a display device (108) capable of displaying images represented by
decocted television signals;

21
a record signal output terminal (15) capable of producing a record video
signal;
a decoder, coupled between the digital data source and the display device
and the record signal output terminal, having a maximum decoding
bandwidth less than that required to simultaneously decode two high
definition television signals at full decoding resolution;
a controller (112) coupled to the decoder, for selecting two respective
ones of the data streams responsive to user input, and if both represent a
high definition television signal, requesting user input for specifying one of
the two respective data streams to decode at partial resolution.
12.The receiver as claimed in claim 11, wherein the controller conditions the
decoder to decode a first one of the selected data streams at full
resolution to provide an image to the display device in response to user
input.
13.The receiver as claimed in claim 11, wherein the controller conditions the
decoder to simultaneously decode the second one of the selected data
streams at partial resolution to provide an image to the display device in
response to user input wherein the image represented by the first one of
the selected data streams forms a main image, and the image
represented by the second one of the selected data streams forms a sub
image.

22
14.The receiver as claimed in claim 13, wherein the controller is responsive
to user input to indicate one of the selected data streams, and provide a
signal represented by the indicated data stream to the record signal
output terminal.
15.The receiver as claimed in claim 14, wherein the controller conditions the
display device to generate the visual cue as a box around the image
represented by the indicated data stream.
16.The receiver as claimed in claim 15, wherein the box is a bold black box.
17.The receiver as claimed in claim 14, wherein the controller conditions the
display device to display an image requesting input from the user whether
to decode the indicated data stream at full resolution or partial resolution,
and responsive to user input conditions the decoder to decode the
indicated data stream at the resolution specified by the user input.
18.The receiver as claimed in claim 17, wherein the controller conditions the
display device to display an image indicating the specified resolution, and
requesting confirming user input.
19.The receiver as claimed in claim 17, wherein if the user input specifies the
indicated data stream should be decoded at full resolution, the controller
conditions the decoder to decode the indicated data stream at full
resolution and supplies the television signal represented by the decoded
indicated data stream to the record signal output terminal, and restricts
data streams representing high definition television programs from being
displayed on the display device.

23
20.The receiver as claimed in claim 19, wherein if the other one of the
selected data streams represents a high definition television signal, the
controller conditions the decoder to decode the other one of the selected
data streams at partial resolution.
21.The receiver as claimed in claim 19, wherein the controller is responsive
to user input to ignore requests that a high definition television signal be
displayed on the display device.
22.The receiver as claimed in claim 19, wherein if the controller receives user
input requesting that a high definition television signal be displayed on the
display device, the controller conditions the display device to display an
image that it is not permitted.
23.The receiver as claimed in claim 22, wherein the controller conditions the
display device to display an image which is a black screen.
24.The receiver as claimed in claim 23, wherein the controller conditions the
display device to display an image which additionally comprises
information informing the user that the decoder is currently decoding a
data stream at full resolution for the record signal terminal displayed atop
the black screen.
25.The receiver as claimed in claim 24, wherein the controller additionally
conditions the display device to display an image requesting user input to
determine whether to stop decoding a data stream at full resolution for
the record signal output terminal and display the requested high definition
television signal on the display device; and

24
if user input specifies that decoding of the data stream at full resolution
for the record signal output terminal is to stop, the controller conditions
the decoder to decode the high definition television signal for the display
device at partial resolution, and simultaneously decode the requested
television at full resolution for display device.
26.The receiver as claimed in claim 25, wherein the controller conditions the
display device to display an image requesting confirmation of the
requested user input.
Dated this 29th day of April, 2002
OF L.S. DAVAR & CO.
APPLICANTS' AGENT

This invention relates to an improved television receiver for selecting two data
streams, a source of digital data comprising a plurality of data streams each
representing one of a standard definition television signal and a high definition
television signal and encoded in such a manner that the data streams may be
decoded at full resolution to produce an image substantially without visible
decoding artifacts or decoded at partial resolution to produce an image with
visible decoding artifacts; a decoder (10) coupled to the digital data source,
having a maximum decoding bandwidth less than that required to simultaneously
decode two high definition television signals at full decoding resolution; and a
controller (112), coupled to the decoder, for selecting two respective ones of the
data streams responsive to user input, and if both represent a high definition
television signal, requesting user input for specifying one of the two respective
data streams to decode at partial resolution.

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Patent Number

226909

Indian Patent Application Number

IN/PCT/2002/558/KOL

PG Journal Number

01/2009

Publication Date

02-Jan-2009

Grant Date

30-Dec-2008

Date of Filing

29-Apr-2002

Name of Patentee

THOMSON LICENSING S.A.

Applicant Address

46 QUAI ALPHONSE LE GALLO F-92648 BOULOGNE, CEDEX

Inventors:

#	Inventor's Name	Inventor's Address
1	COMER MARY, LAFUZE	2571 WEST 975 SOUTH, FAIRMOUNT, IN 46928
2	HORLANDER, THOMAS, EDWARD	6234 HAVERFORD AVENUE, INDIANAPOLIS, IN 46220

PCT International Classification Number

H04N 5/44

PCT International Application Number

PCT/US00/30385

PCT International Filing date

2000-11-03

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	60/163,609	1999-11-04	U.S.A.