Patent Publication Number: US-2007098372-A1

Title: Digital television recorder for recording multiple sets of audio tracks and method thereof

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a system and method thereof for recording a digital television broadcast onto a storage medium, and more particularly, to a system and method for recording multiple audio tracks from a digital television program broadcast.  
      2. Description of the Prior Art  
      Digital television (DTV) is a recently commercialized broadcasting system, which provides its viewers with many more options and choices in television viewing than traditional analog television. The high bandwidth efficiency used in the transmission of DTV allows for more data to be sent, resulting in many more features and configurations in the viewed program. TV broadcasts offer a vastly superior screen resolution, user selectable viewing aspect ratios, and adjustable audio configurations. Many of these new features are not available through traditional analog television, and as such, DTV serves to represent the future in television viewing.  
      With DTV, not only does the viewer have the option of choosing the appropriate subtitles and display languages for a specified program, but the viewer can also select the specific audio or language tracks to be played during the program as well. The audio track may contain the program dialogue in an alternate language, sound effects, audio standards and configurations, music soundtracks, or other peripheral audio tracks. Many DTV broadcasts also contain supplemental data tracks, which may include hypertext transmission for internet linking, or feedback sensory information.  
      In order to record a DTV broadcast, a DTV compatible recorder is required. This is an apparatus that stores the viewed program onto a digital medium. Most DTV recorders typically record the solely viewed video track, along with the specific user selected set of audio tracks during the broadcast. For instance, if a program is viewed with French as the selected language, English subtitles, and a stereo audio configuration, a playback of this program on the DTV recorder will re-enact this exact same setup upon playback without any possibility of an alternate configuration.  
      With the extra bandwidth available through DTV, and the improving methods of satellite and DTV broadcasting, one expects that even more information streams and data sets will be available for each broadcasted program in the near future. This may include further multiple audio streams, video streams, multi-angle displays, feedback and sensory streams, and other potential peripheral data streams. These features will undoubtedly serve to increase the excitement and entertainment value of a live digital broadcast.  
     SUMMARY OF THE INVENTION  
      An objective of the invention is to record a DTV program with multiple sets of audio tracks corresponding to the chosen program in order to provide the viewer with the same excitement and flexibility of a live DTV broadcast upon playback of a recorded DTV program. This will allow the user to have the same flexibility and controllability that they would experience in a live broadcast, resulting in a truly accurate reproduction of a live DTV broadcast.  
      According to an exemplary embodiment of the claimed invention, a digital television (DTV) recorder is disclosed comprising a tuner coupled to an incoming RF signal for selecting a carrier frequency and outputting a corresponding transport stream, a program de-multiplexer coupled to the transport stream for outputting at least one selected program service, a track selector coupled to the program de-multiplexer for selecting a plurality of sets of audio tracks from the selected program service, and a storage module coupled to the track selector for storing the DTV program with selected sets of audio tracks onto a storage medium.  
      According to another exemplary embodiment of the claimed invention, a method for recording a digital television (DTV) is disclosed comprising selecting a carrier frequency from an RF input and outputting a corresponding transport stream, selecting a program service from the transport stream, selecting a plurality of sets of audio tracks from the program service, and storing a DTV program with the selected sets of audio tracks onto a storage medium.  
      These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a drawing of a DTV recorder according to a first exemplary embodiment of the present invention.  
       FIG. 2  is a detailed drawing of an embodiment of the track selector module within the DTV recorder of  FIG. 1 .  
       FIG. 3  is a detailed drawing of the storage module of  FIG. 1 .  
       FIG. 4  is a process flow chart of the recording method of the DTV recorder of  FIG. 1 .  
       FIG. 5  is a DTV recorder according to a second exemplary embodiment of the present invention.  
       FIG. 6  is a DTV recorder according to a third exemplary embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION  
      While the viewing of a live DTV broadcast can be an exciting, exhilarating and flexible process, the viewing of a previously recorded DTV program can be rather confined and restricted. In a typically recorded DTV program, the user cannot select an alternate set of audio tracks, or any other possible viewing configuration for playback. These configurations may include: language options, subtitles, viewing angles, supplemental data, and audio configurations. The viewing configurations for the recorded program are predetermined by the settings at the time of which recording took place. Current DTV recorders do not allow for the viewer to change the sets of audio tracks and other relevant options and configurations to an alternate configuration upon playback.  
       FIG. 1  illustrates a DTV recorder  100  according to a first exemplary embodiment of the present invention. In this embodiment the DTV recorder  100  is integrated into a DTV receiver, however please note that other embodiments and configurations may exist. A radio frequency (RF) signal  101  is broadcasted by a network provider to the DTV recorder  100  as shown in  FIG. 1 . The broadcast network can be a cable network, satellite network or a terrestrial broadcast network transmitting digital information. The transmitted information is received by the digital tuner  110 , which tunes into and isolates a specific carrier frequency of the RF Signal  101 . For example, different carrier frequencies could correspond to different network providers. A specific carrier frequency is then selected and isolated, producing a transport stream  102  that is outputted from the digital tuner  110 .  
      The transport stream  102  contains the entire group of various program channels corresponding to the specific carrier frequency as transmitted by the network provider. This stream is de-modulated using a de-multiplexer  120  in order to selecting a single program service  103  corresponding to a single broadcasted program. The program service  103  itself contains a plurality of different audio, video, and supplemental data tracks. For example, a broadcasted movie may contain multiple video tracks. The program may have a standard video track corresponding to a standard visual display, and an alternate video track for a wide-screen version, or possibly another video track for different camera angles. The same movie may also have several independent sets of audio tracks reserved for multi channel audio configurations. A mono configuration requires one audio track for playback, while a stereo setup requires two audio tracks, and a Dolby Digital 5.1 requires six independent tracks, and typically each set of audio tracks also corresponds to an alternate language (such as French or Spanish). The supplemental data tracks in the program service  103  may contain tracks for closed captioning or subtitles, hypertext links for interactive programming, or other peripheral features.  
      When viewing a DTV broadcast, typically only a preferred audio visual configuration is shown from the program service  103 . This generally means a single video channel, a single language dialogue setting, a single (if any) set of subtitle dialogue, a single audio theater configuration and so forth. The configuration is setup such that there are no two sets of the same potentially conflicting information types. Audio-visual tracks not used in viewing are blocked off and prevented from further propagation in the processing chain. For example, if a DTV broadcast includes multiple language tracks, only the single language selected for playback is generally recorded by DTV recorders of the related art.  
      To overcome this problem, and allow multiple sets of audio tracks (and supplemental data tracks likewise) to be recorded along with the DTV program, a track selector  130  is utilized for selecting a plurality of sets of audio tracks, video tracks and supplemental data tracks from the selected program service  103 . The supplemental data tracks may include various subtitle dialogue, hyperlinking data, and other peripheral data streams. The track selector  130  is coupled to the de-multiplexer  120  to receive the program service  103  containing the entire audio-visual and data track information.  
      In one embodiment, the track selector  130  operates through a user interface  140 , through which a user can specify desired sets of audio tracks to record. The user interface  140 , displays the available sets of audio tracks, supplemental data tracks and video tracks to the user, and thereby allows the user to choose which tracks are passed to the storage module  150 . For example, the user can specify at least one video and supplemental data track via the user interface  140 , such that the track selector  130  can select a default video source and supplemental data source. The user interface  140  can also further operate in a manual recording mode, where a user can manually select a desired configuration for recording.  
      Once the desired sets of audio, video and supplemental data tracks are specified by the user, the user interface  140  controls the track selector  130  to select these tracks from the plurality of available sets of audio, video and supplemental data tracks from the program service  103 . This desired data stream is then outputted by the track selector  130  and sent to the storage module  150 . The storage module  150  is directly coupled to the track selector  130  output, and acts to store the selected sets of audio, video and supplemental data tracks from the program service  103  onto a desired digital storage medium.  
      By passing a plurality of sets of selected audio tracks from the program service  103  to the storage module  150 , different languages of the recorded DTV program are thereby available during playback. For example, if the original DTV broadcast includes a plurality of five languages (e.g., English, Chinese, French, Spanish, and Japanese), a user of the DVD recorder  100  can select to record the audio tracks for any or all of these five languages for storage and later playback. In this way, if the user selects English and Chinese audio to be recorded, the track selector  130  will pass all the audio tracks associated with English and Chinese to the storage module  150 . The actual number of audio tracks passed to the storage module  150  by the track selector  130  depends on the particular multi channel audio configuration for each language. That is, if the English audio is provided as Dolby Digital 5.1, then six audio tracks corresponding to the English audio set will be passed to the storage module  150 . Likewise, if the Chinese audio is provided as stereo, then two audio tracks corresponding to the Chinese audio set will be passed to the storage module  150 .  
      Should the user desire more flexibility and options in viewing a recorded DTV program, the user can utilize the track selector  130  to select all of the audio tracks from the program service  103 , and store all of the audio tracks onto the storage medium through the storage module. In this manner, the user will have the full variety of languages to select from upon playback, similar to the original DTV broadcast. In the same manner, the user could also choose to select all of the available subtitle and video tracks to record as well. However, recording in this manner will consume the most storage space from the storage medium, and as such, the user may elect to select only the desired audio/visual sets as previously described in an effort to reduce storage consumption.  
      Flexibility and further control of the DTV recorder  100  can be enhanced through the addition of a timer module  160 . In this embodiment, the timer module  160  is coupled to the user interface  140 , and can direct the DTV recorder  100  to record a particular DTV program at a future time as appointed by the user. If a user wants to record a DTV program that has yet to commence, the user would enter the desired recording configuration, including the desired sets of audio tracks to record, and also enter the future recording time through the user interface  140 . The user interface allows the user to choose the desired group of sets from the audio tracks to be recorded at a particular forthcoming time. That is, the user can select which languages of the DTV program to pass to the storage module  150  and make available for playback. The timer module  160  would then direct the DTV recorder  100  to record the desired program with the selected sets of audio tracks at the user defined time according to the configuration already set by the user.  
       FIG. 2  shows a block diagram of an embodiment of a track selector  200 . The track selector  200  shown in  FIG. 2  can be utilized to implement the track selector  130  of  FIG. 1 . Although one embodiment of track selector  130  is shown here, please note that other possible embodiments of track selector  130  also exist. The full contents of the program service  103  are inputted into the track selector  200 . As described above, the audio tracks of the program service  103  are typically categorized into different sets, which may correspond to different language groups. For example, one set may correspond to all the audio channels relevant to English language viewing, while another set may contain all the audio channels relevant to Spanish language viewing. The track selector  200  hence operates as a filtering mechanism of sorts, comprising a plurality of filters  202  to allow the desired sets of audio, visual and supplemental tracks to output to the storage module  150  for recording. Sets not chosen by the user, are not passed through the corresponding filters  202 , and are therefore not recorded by the storage module  150 . For example, if audio sets  1  and  3  are selected for recording, then the filters  202  for the other audio sets will be blocked, and only audio sets  1  and  3  will be passed to the storage module  150 .  
       FIG. 3  shows a possible embodiment for a storage module  300 . The storage module  300  shown in  FIG. 3  can be utilized to implement the storage module  150  of  FIG. 1 . As shown in  FIG. 3 , the storage module  300  comprises a multiplexer  310 , a storage control unit  320 , and a storage medium  330 . Although one embodiment is shown here, please note that other possible embodiments of storage module  150  also exist. The output of the track selector  130  is accepted by the multiplexer  310 , and is accordingly processed. Digital broadcasts are typically compressed using the MPEG compression algorithm standard for DTV. The processed audio-visual data is sent to the storage control unit  320 , which accordingly organizes the data, and records the data onto the storage medium  330 . In preferred embodiments, the storage medium  330  is of digital format, and may be implemented as a hard disk drive, flash memory, a CD disc, or a DVD disc.  
       FIG. 4  displays a process flow chart  400  of a method for recording a DTV program according to an exemplary embodiment of the present invention. Provided that substantially the same result is achieved, the steps of the process  400  need not be in the exact order shown and need not be contiguous, that is, other steps can be intermediate. This method allows a user to record a program with the desired sets of audio tracks onto a storage medium and includes the following steps:  
      Step  410 : Select a carrier frequency from an RF broadcast, isolate the frequency, and output a corresponding transport stream.  
      Step  420 : Select a program from the transport stream output in Step  410 , de-modulate the signal, and output a program service.  
      Step  430 : Select desired sets of audio tracks from the program service for recording.  
      Step  440 : Select sets of supplemental data tracks from the program service.  
      Step  450 : Store the DTV program with the selected sets of audio and supplemental data tracks onto the storage medium.  
      In another mode of process  400 , step  430  can consist of selecting all the sets of audio tracks from the program service, and the final step  440  consists of storing all sets of audio tracks onto the storage medium. In this way, on playback, the user will have the full variety of languages to select from, similar to the original DTV broadcast. Because this mode elects to select and record all audio tracks onto the storage medium, this mode would also require the most memory and storage space. Should the user wish to reduce storage consumption on the recording medium, the user may choose to personally select only the desired sets of audio tracks to record, as described in the original step  430  shown in  FIG.4 .  
       FIG. 5  is a DTV recorder according to a second exemplary embodiment of the present invention. In this embodiment, the DTV recorder is integrated into a personal computer  500 . A tuner card  510 , is utilized to receive an RF signal from an incoming broadcast source. A processor  520  is coupled to the tuner card and utilized to carry out the process flow as illustrated above in process  400 . Also included in the embodiment is storage module  530 , which is used to store the selected program of process  400  onto a desired storage medium such as a hard disk drive or optical disc.  
       FIG. 6 . shows yet another embodiment of a DTV recorder integrated into a set top box  600  according to the present invention. The set top box  600  comprises a DTV receiver  610 , and a DTV recorder  620 . The DTV receiver  610  is coupled to the incoming RF signal from the broadcast source. The incoming RF signal is then accordingly processed, and outputted as a composite audio-video signal for the digital television  630 . The DTV receiver  610  is further coupled to a DTV recorder  620 . The DTV recorder  620  acts to record the desired program following the process flow illustrated in the above by process  400 .  
      According to the present invention, a digital television (DTV) recorder includes a tuner coupled to an incoming RF signal for selecting a carrier frequency and outputting a corresponding transport stream. A program de-multiplexer is coupled to the transport stream for outputting at least one selected program service, and a track selector is coupled to the program de-multiplexer for selecting a plurality of sets of audio tracks and supplemental data tracks from the selected program service. Finally, a storage module is coupled to the track selector for storing the selected sets of audio tracks and supplemental data tracks onto a storage medium. By passing a plurality of sets of selected audio tracks from the program service to the storage module, different languages of the recorded DTV program are thereby available during playback. A user interface and timer module can be included to further increase the versatility and convenience of recording DTV programs.  
      Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.