Patent Application
20080225167
An embodiment of the invention relates to a method of displaying video pictures. A further embodiment of the invention relates to a receiver providing a video picture.
Today, a large number of television channels exist and it is expected that the number of television channels will further increase in the future. In order to provide an overview of a large number of television channels thumbnail views may be used. A thumbnail view shows a plurality of small pictures, i.e. thumbnails, on one screen.
In order to increase user's acceptance, it is desirable that the thumbnails show the live television picture of the corresponding television channel, i.e. each thumbnail picture should continuously be updated in real-time. In other words, each thumbnail picture should be a moving video picture corresponding to the live picture of a respective television channel.
In prior art, thumbnails of a thumbnail view are often only updated within a certain interval of time, i.e. no live pictures are shown as thumbnails but still pictures that are updated once in a while.
It is an object of the invention to provide a method of displaying video pictures, wherein thumbnails of a thumbnail view correspond to live picture of a corresponding television channel. It is a further object of the invention to provide a receiver generating an output signal for a display, which output signal comprises a thumbnail view of live video pictures.
These objects are solved by a method and receiver according to claims 1, and 14, respectively.
Further details of the invention will become apparent from a consideration of the drawings and ensuing description.
In the following, embodiments of the invention are described. It is important to note, that all described embodiments in the following may be combined in any way, i.e. there is no limitation that certain described embodiments and/or features may not be combined with other embodiments and/or features.
According to an embodiment of the invention, a method of displaying video pictures may comprise: receiving a first video signal or a stream of a first standard, which first video signal or stream comprises a first video picture, displaying said first video picture, receiving a second video signal or stream of a second standard, which second video signal or stream comprises at least one second video picture, wherein said second standard is different from said first standard, switching to a thumbnail view, and displaying said at least one second video signal in said thumbnail view.
The first and second standard can e.g. be a transmission standard, television standard, compression standard or coding standard. The term “standard” thus defines e.g. the needed bandwidth for transmission of a video picture when transmitted, the size of the picture, a frequency or frequency range used for transmission, the format of a data stream used for transmission and/or the like. The first and second video signal may be broadcast signals e.g. transmitted via satellite, terrestrial, via cable or wireless. It is, however, also possible that the first and second video picture are transmitted via the internet and the first and second standard correspond to different standards of coding.
As seen in
In step S104 a second video signal is received which comprises at least one second video picture. It is possible that said second video signal comprises a plurality of video pictures, e.g. transmitted at a same frequency, within a same frequency band and/or within a same data stream. In this case, the first video picture may be transmitted at a different frequency, within a different frequency range and/or within a different data stream.
In step S106, switching to the thumbnail view occurs.
In step S108 the at least one second video picture is displayed in the thumbnail view, i.e. each video picture of said second video signal is displayed as a thumbnail.
In step S204 the user may switch to thumbnail view, e.g. by pressing a respective button on a remote control of a television set or receiver. Therefore, in step S206, tuning to the second video signal occurs. If the second video signal is transmitted at a different frequency, different frequency band or different video stream than said first video signal, the tuner may tune to the frequency/data stream of the second video signal upon the switching operation.
As mentioned, it is possible, that the second video signal comprises a plurality of second video pictures corresponding to different television channels. However, it is possible that not all second video pictures included in said second video signal shall be displayed in thumbnail view. Therefore, in step S208, second video pictures of the second video signal may be selected.
In step S210, the selected second video pictures are displayed in thumbnail view.
As shown in
Upon selection of a certain thumbnail corresponding to a second video picture of said second video signal, in step S302, tuning to a corresponding first video signal occurs. The corresponding first video signal corresponds to the television channel of the selected thumbnail. For example, if the user selects a thumbnail corresponding to the television channel CNN, then tuning to the first video signal corresponding to the television channel CNN may occur. Thereby, it is possible that tuning to a corresponding frequency/data stream occurs, wherein the frequency/data stream is determined by the corresponding television channel, in the example, CNN. In other words, upon selection of a thumbnail that is transmitted within the second video signal, tuning to the first video signal occurs, wherein e.g. the tuning frequency depends on the selected thumbnail.
In step S304, the corresponding decoded first video picture is displayed. Thus, according to this embodiment of the invention, the user is able to select a television channel by selecting a thumbnail, which thumbnail is transmitted by the second video signal, wherein, upon selection of a thumbnail, tuning to a corresponding first video signal occurs, and the corresponding first video picture is displayed.
In a further embodiment, the first standard may be a full resolution video standard, e.g. enabling transmission of said first video picture in full resolution, and said second standard may be a reduced resolution standard, e.g. enabling transmission of said at least one second video signal with reduced resolution. Because said second video standard allows transmission of video pictures with reduced resolution, the need bandwidth for enabling the thumbnail view may be reduced.
In a further embodiment, said first video standard may be selected from the group consisting of analogue television standard, digital video broadcast terrestrial standard (DVB-T), digital video broadcast cable standard (DVB-C), digital video broadcast satellite standard (DVB-S), broadband internet protocol television standard (IP-TV) and/or said second standard may be selected from the group consisting of digital video broadcast handheld standard (DVB-H), digital multimedia broadcast terrestrial standard (T-DMB), and narrowband internet protocol television standard (IP-TV).
In a further embodiment, the second standard may enable transmission of a video picture with a lower bandwidth than said first standard. For example, in said second standard, a video picture may be smaller than in said first standard. Also, it is possible that, in said second standard, a higher compression of a video picture may occur than in said first standard. Still further, it is possible that in said second standard a lower frame rate, e.g. 12,5 frames per second, is used than in said first standard. In said first standard e.g. a frame rate of 25 frames per second is used.
In a further embodiment, the second video signal may comprise at least two second video pictures that are transmitted at a same frequency, within a same frequency band and/or within a same data stream. It is, thus, possible that the second standard allows transmitting of a plurality of video pictures at one frequency, within one frequency band and/or within one data stream. Also, the second video signal may comprise a larger number of video pictures, e.g. 10 to 20, 20 to 30, or even more. In general, the second video signal and/or the second video standard may allow to decode a large number of e.g. television channels at the same time, and the first video signal and/or first video standard may only allow decoding a small number of channels. Maybe the first video signal does not allow decoding the channels that should be displayed in the current thumbnail view.
In a further embodiment, the first standard is the digital video broadcast terrestrial standard (DVB-T) and the second standard is the digital video broadcast handheld standard (DVB-H). In this case, the first video signal may comprise 4 to 5 television channels, i.e. video pictures, and the second video signal may comprise 20 , to 30 services, i.e. television channels/video pictures, per frequency and/or frequency band. If the first standard is the digital video broadcast terrestrial standard (DVB-T) and the second standard is the digital video broadcast handheld standard (DVB-H) it may be possible that a same physical layer may be used and only different software needs to be provided on top of this same physical layer. In other words, according to this embodiment, there may be no or only very few hardware adaptations necessary to a prior art DVB-T receiver.
In a further embodiment, the first and second video signals are decoded using a same tuner, a same de-multiplexer and/or a same hardware. Thus, according to this embodiment, it may be possible to only provide one tuner and only one demultiplexer. Both, the tuner and the de-multiplexer are used to selectively tune to and decode a DVB-T or DVB-H signal.
In a further embodiment, when switching to the thumbnail view, the same tuner may be tuned to the second video signal of the digital video broadcast handheld standard DVB-H. In other words, upon switching to the thumbnail view, e.g. a receiver may start decoding a plurality of second video pictures provided by a DVB-H signal.
In a further embodiment, the first video picture may correspond to a television channel which is selected from a set of available or predetermined television channels of the digital video broadcast terrestrial standard (DVB-T), and the second video pictures of the thumbnail view may comprise only video pictures corresponding to the available or predetermined television channels. For example, HBO and CNN may be available television channels in DVB-T standard. In DVB-H standard there is also BBC available, which is, however, not available in DVB-T standard. Because only HBO and CNN are available in DVB-T standard, only HBO and CNN are displayed in the thumbnail view and not BBC.
In a further embodiment, if no second video picture corresponding to a respective available or predetermined television channel of the digital video broadcast terrestrial standard (DVB-T) is available, a message is displayed in the thumbnail view instead of the thumbnail, indicating that no preview of the respective channel is available. In the example from above, there may be a local television channel available in DVB-T standard, which local television channel is, however, not available in DVB-H standard. Thus, in the thumbnail view, instead of a thumbnail for the local television channel, a blank thumbnail would appear possibly comprising a message such as e.g. “no preview available”.
In a further embodiment, a certain television channel may be selectable within the thumbnail view by moving a cursor to a certain thumbnail.
Further, it may be possible, that, upon selection of a certain television channel, the tuner is tuned to a selected first video signal corresponding to the certain television channel in said digital video broadcast terrestrial standard (DVB-T). For example, the thumbnail view may show thumbnails of CNN and HBO. By moving the cursor to the thumbnail of CNN and selecting this thumbnail, the tuner is tuned to the first video signal corresponding to the DVT-T signal of CNN.
In a further embodiment, the at least one second video picture may be used without resizing for the thumbnail view. As mentioned above, in an embodiment of the invention, it is possible that the second standard allows transmission of video pictures with a lower needed bandwidth than said first standard. As also mentioned above, this may be achieved, because in said second standard, the video picture is smaller than in said first video picture. Thus, it may be possible to use the decoded second video pictures without resizing. This way, needed hardware and/or processing power may be reduced.
In a further embodiment of the invention, a computer program product, e.g. a computer readable medium or downloadable executable or pre-installed program on a computer and/or signal processing means, may be provided, including computer program instructions that cause a computer to execute a method of displaying video pictures as explained above.
In a further embodiment of the invention, a receiver may comprise a tuner configured to tune to a first video signal comprising a first video picture of a first standard, and further configured to tune to a second video signal comprising at least one second video picture of a second video standard, which is different from said first standard, and further configured to provide a respective video stream or video signal comprising said first and second video picture, respectively. The tuner or receiver may further comprise an output signal generating mechanism configured to generate an output signal for a display, e.g. a display of a television, wherein, if said tuner is tuned to said first video signal, said output signal comprises said first video picture, and else, if said tuner is tuned to said second video signal, said output signal comprises a thumbnail view of said at least one second video picture.
In a further embodiment of the invention, the tuner may be the only tuner of the receiver.
The receiver, in a further embodiment, may further comprise a selection mechanism, configured to allow selection of a user selected second video picture of said thumbnail view, wherein, upon selection of said user selected thumbnail, said tuner tunes to a certain first video signal comprising a same video picture as said user selected second video picture and provides a video stream comprising said first video picture.
In still a further embodiment of the invention, a method of displaying video pictures may comprise: displaying a first video picture of a first standard, receiving at least one second video picture of a second standard which is different from said first standard, switching to a thumbnail view, and displaying said at least one second video picture in said thumbnail view.
In a further embodiment of the invention, means for displaying video pictures may be provided, comprising: means for displaying a first video picture of a first standard, means for receiving at least one second video picture of a second standard which is different from said first standard, means for switching to a thumbnail view, and means for displaying said at least one second video picture in said thumbnail view.
Upon selection of the thumbnail view in step S400, in step S402, the tuner tunes to the DVB-H signal, also referred to as DVB-H stream.
Then, in step S404, the first television service in a DVB-T service list 405 is selected. The DVB-T service list 405 e.g. comprises all television channels that are available in DVB-T standard or a predetermined set of television channels that are available in DVB-T standard.
Then, in step S406, it is checked, if the selected television service of the DVB-T service list 405 is also available in the DVB-H stream. If e.g. the selected television service of the DVB-T service list 405 is television channel CNN, then it is checked whether CNN is included in the DVB-H stream. Note that the DVB-H stream may comprise a plurality of television channels.
If the television service, e.g. a television channel, is available in the DVB-H stream, then, in step S408, decoding of the respective service from the DVB-H stream starts. The decoded picture is then displayed as thumbnail in step S410.
On the other hand, if, in step S406, the selected television service of the DVB-T service list 405 is not available in the DVB-H stream, than in step S412, a message as e.g. “no preview” is displayed instead of a thumbnail. Alternatively, a still picture could be displayed as thumbnail, which still picture had been captured previously while the tuner had been tuned to the corresponding channel. Therefore, the tuner, when tuned to a certain channel, e.g. transmitted via DVB-T, may store a still picture of that channel, which still picture may later on be used as thumbnail. Further, as still picture a predetermined picture could be used. For example, as predetermined picture, a respective logo of a television station could be used. Alternatively or additionally, a same still picture could be used for all or at least one of the television stations for which no thumbnail view is possible. Of course, it is also possible that only if a logo of a respective television station is available, the logo is shown, and if a logo is not available, a predetermined still picture is shown.
Another possibility may also be to omit a respective thumbnail completely if no respective picture for thumbnail view is available. Thus, if no thumbnail view is possible for a certain television station, then there would be no thumbnail and no message “no preview”.
In step S414, the next service in the DVB-T service list 405 is selected.
In step S416, it is checked whether the last service in the DVB-T service list 405 has been reached or if the thumbnail screen is full. If not, then processing continues in step S406.
If yes, i.e. the last service has been reached or the thumbnail screen is full (step S416), then, in step S418 a navigation cursor is enabled. In step S420, the user may use the navigation cursor to select a thumbnail.
Upon user selection of a thumbnail, in step S422, tuning to the DVB-T channel corresponding to the user selection is performed. Further, in step S424, the respective DVB-T channel is displayed in full screen.
Tuner 502 is configured to tune to a first video signal comprising a first video picture of a first standard, e.g. digital video broadcast terrestrial (DVB-T) and to tune to a second video signal comprising at least one second video picture of a second video standard, which is different from said first video standard. The second video standard may e.g. be the digital video broadcast handheld DVB-H standard. The tuner may further be configured to provide a respective video stream 503 comprising the first and second video picture, respectively.
Output signal generator 504 receives the video stream 503 and generates an output signal 508 for a display e.g. a display of a television set. If tuner 502 is tuned to the first video signal, e.g. DVB-T signal, the output signal comprises the first video picture, and else if the tuner 502 is tuned to the second video signal, e.g. DVB-H signal, the output signal comprises a thumbnail view of the at least one second video picture of the second standard.
As shown in
Selector 610 is configured to allow selection of a thumbnail view and further configured to allow selection of a thumbnail of the thumbnail view.
If the user selects the thumbnail view, selector 610 controls tuner 602 to tune to the second video signal, e.g. DVB-H signal, and provide a respective video stream 603 comprising at least one second video picture. In this case, output signal generator 604 decodes the video picture(s) of video stream 603 and provides the thumbnail view.
On the other hand, if the user selects a thumbnail of the thumbnail view, selector 610 controls tuner 602 to tune to the corresponding first video signal, e.g. DVB-T signal, and to provide a respective video stream 603. Selector 610 further controls output signal generator 604 to decode video stream 603 and to provide the corresponding television picture in full screen e.g. to a television connected to receiver 600. Of course, it is possible that the receiver 600 be incorporated into a television. In this case, the output signal 608 is used within the television to display the respective television picture.
DVB-T/H signal is received by tuner 702 deriving a transport stream 703. Transport stream 703 is provided to de-multiplexer 704. De-multiplexer 704 generates a DVB-T audio and video stream or DVB-H audio and video stream. If the thumbnail view is selected, than de-multiplexer 704 generates a DVB-H video stream and DVB-H audio stream. If, however, no thumbnail view is selected, i.e. the user wants to watch a television program in full screen, then de-multiplexer 704 provides a DVB-T video stream and DVB-T audio stream.
Signal processor 706 generates an output signal 707 comprising either a picture 708 in full screen of a DVB-T stream or a thumbnail view 712 comprising thumbnails 708′, 709′, 710′, 711′, . . . of pictures of the DVB-H stream.
As seen, in thumbnail view 712, picture 708 of the DVB-T stream may be included as thumbnail 708′. If a television channel that is available via a respective DVB-T signal is not available or included in the DVB-H stream, then in thumbnail view 712, a respective message may appear instead of a thumbnail picture. As seen in
The operation according to DVB-T is shown in the upper half of
In DVB-H operation, tuner 800 may be operated in 4K mode and generates a transport stream 801-B. It is also possible that tuner 800 be operated in 2K or 8K mode. In general, both standards, i.e. DVB-T and DVB-H are using COFDM modulation which has several modulation modes. For DVB-T the modes “2K” and “8K” are allowed. For DVB-H the standard had been extended to allow “2K”, “4K” and “8K” mode. Therefore, it is not required that the transmission is using 4K mode as shown in
Based on transport stream 801-B, de-multiplexer 802 derives an IP container 808. IP container 808 comprises a DVB-H video stream 810 and DVB-H audio stream 812. DVB-H video stream 810 comprises a small picture, e.g. 320×240 pixels, at a lower frame rate, e.g. 12,5 frames per second, wherein as codec MPEG4 may be used.
Tuner 800 and de-multiplexer 802 correspond to hardware components as indicated by the pattern corresponding to hardware realizations (see legend of
Thus, according to an embodiment of the invention, a method for creating live video mosaics on digital television receivers may be provided. Currently, in DVB-T transmissions there is no mosaic service (thumbnail view) available as it exists for some DVB-S providers. The DVB-S providers, however, need to provide a special channel transmitting the thumbnail view.
As shown above, according to embodiments of the invention, it is possible that a thumbnail screen with live video pictures be provided by using a modified DVB-T operation and including DVB-H operation.
According to the embodiments, it is thus possible to provide a thumbnail view, which is not possible for DVB-T, because in DVB-T services, i.e. television channels, are spread over a number of frequencies. In order to provide a thumbnail view based only on DVB-T signal, the tuner would need to be returned to access all the services and this would stop the live playback of other services, i.e. it would not be possible to provide live thumbnail pictures.
This drawback is overcome as described above, because a thumbnail view with many live video pictures can be generated with all channels in the channel list. The thumbnail generation is, thereby, independent from the service providers. Further, the technical effort to decode DVB-H on a DVB-T receiver is relatively small: the transmitting frequencies are the same, the stream format is the same, only the size, frame rate and codec of the video content is different. Note that the DVB-H codec, e.g. advanced video codec AVC, MPEG4, is standardized and about to be implemented for DVB-T as well.
The different size and frame rate in DVB-H is an advantage: the video picture would need to be resized to a thumbnail picture anyway. Therefore, the smaller DVB-H picture may be used as thumbnail without resizing.
Further, as is apparent from the above, only one tuner may be required. Also, no multimedia home platform MHP may be required as would be the case for DVB-S mosaic. A multimedia home platform is a technology, e.g. used in Europe or other countries, for offering interactive TV-related multimedia applications. Applications such as DVB-S/C mosaic services can, but must not, be made using the MHP mechanism. In this case the broadcaster or signal provider must make and maintain the mosaic application. This is not a build-in feature of a television set or set top box. Very few receivers in Europe support MHP. Another technology according to prior art that could be used is the MHEG which is a system competing against MHP. MHEG is only used in the United Kingdom UK and has fairly good support by the receivers sold in UK. Other solutions that could be used for DVB-S/C mosaic services are provider's specific software implementations on set top boxes with provider's specific software versions (some cable network providers distribute their own boxes with own software). However, all of this complicated additional software/hardware may not be needed when using a method of displaying video pictures as explained above.
| Number | Date | Country | Kind |
|---|---|---|---|
| 07005296.4 | Mar 2007 | EP | regional |
