Abstract:
A system and method for replacing all or part of the original audio of a digital program with other audio enables a user to customize a digital program soundtrack. The method includes receiving the audio portion of the digital program as an audio data stream including multiplexed associated audio and data packets, selecting at least one of the audio packets to be replaced by a replacement audio packet, and replacing the at least one of the audio packets with a replacement audio packet thereby customizing the audio portion of the digital program during program playback. The method also enables customizing an audio portion of a transmitted analog program. The method includes receiving first and second audio signals, receiving information transmitted in a vertical blanking interval of the transmitted analog program, interpreting the information and removing a replaceable audio signal, and replacing the replaceable audio signal with a user-selected audio signal.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates generally to the field of home entertainment systems, and more particularly to a system and method for enhancing and customizing playback of soundtracks. 
       BACKGROUND INFORMATION 
       [0002]    Currently, broadcast video, video cassette recorders, and digital video disk (DVD) players limit a user&#39;s input to a standard set of functions, which includes play, pause, and stop, for example. Some DVDs also include, on an extended soundtrack disk, additional songs that were not part of the original movie soundtrack. However, there does not exist a system for replacing the prerecorded audio portion of a digital or analog program or presentation with music from an extended soundtrack or music from another source during movie playback in personal home entertainment systems. 
         [0003]    A typical Digital Video Disc (DVD) format includes MPEG-2 video/audio encoding. In MPEG-2 encoding, video and audio are separated into different streams (identified by distinct program identifiers (PIDs) in the header of each MPEG-2 packet). It would be highly desirable to provide a system and method for home entertainment systems that removes or replaces a program&#39;s prerecorded audio soundtrack, with other audio, e.g., music, that is customized for the viewer. 
       SUMMARY OF THE INVENTION 
       [0004]    The invention relates generally to the field of home entertainment systems, and more particularly to a system and method for enhancing playback of soundtracks in analog or digital programs, such as broadcast television (digital or analog), or prerecorded analog or digital movies. The present invention involves a method and apparatus for replacing all or part of a program&#39;s prerecorded audio soundtrack (e.g., music that is played by default) with other audio that is customized for, or by, the viewer. 
         [0005]    In one aspect, the invention involves a method for customizing an audio portion of a digital program. The method includes receiving the audio portion of the digital program as an audio data stream including multiplexed associated audio and data packets, selecting at least one of the audio packets to be replaced by replacement audio packet, and replacing the audio packets with a replacement audio packet and thereby customizing the audio portion of the digital program during program playback. 
         [0006]    In one embodiment, the method includes storing the plurality of audio packets in an audio buffer. In another embodiment, the method includes storing the replacement audio packet in a replacement audio buffer. In still another embodiment, the method includes creating an audio characteristics table based on information from the data packet associated with the at least one of the plurality of data packets. In yet another embodiment, the method includes creating a replacement audio table that includes information corresponding to the replacement audio packet. In other embodiments, selecting at least one of the audio packets to be replaced includes determining an audio packet program identifier from a program specific information table for the at least one of the audio packets to be replaced, and storing the audio program identifier in an audio characteristic table. In another embodiment, the method includes identifying during playback of the digital video the at least one of the audio packets to be replaced by reading an audio program identifier from a header in the associated data packet. In still another embodiment, the method includes consulting the audio characteristics table and modifying the audio characteristics of the replacement audio packet to match the audio characteristics of the at least one of the audio packets. In yet another embodiment, replacing the at least one of the audio packets with the replacement audio packet includes retrieving the replacement audio packet from the replacement audio buffer and multiplexing the replacement audio packet with the audio data stream. In still another embodiment, the method includes retrieving the replacement audio packet from a DVD or CD. In other embodiments, the method includes demultiplexing the data stream to separate the plurality of associated audio and data packets. 
         [0007]    In another aspect, the invention involves a system for customizing an audio portion of a digital program. The system includes a means for receiving the audio portion of the digital program as an audio data stream that includes multiplexed associated audio and data packets. The system further includes a graphical user interface for selecting at least one of the audio packets to be replaced by replacement audio packets, and a control system for replacing the at least one of the audio packets with a replacement audio packet and thereby customizing the audio portion of the digital video during program playback. 
         [0008]    In one embodiment, the control system includes random access memory and an audio processor. In another embodiment, the system includes a data storage means for storing the audio packets. In still another embodiment, the system includes a data storage means for storing the replacement audio packet. In yet another embodiment, the system includes a demultiplexing means for demultiplexing the data stream to separate the associated audio and data packets. 
         [0009]    In still another aspect, the invention involves a program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for customizing an audio portion of a digital program. The method steps include receiving the audio portion of the digital video as an audio data stream that includes multiplexed associated audio and data packets, selecting at least one of the audio packets to be replaced by replacement audio packet, and replacing the at least one of the audio packets with a replacement audio packet thereby customizing the audio portion of the digital program during program playback. 
         [0010]    In yet another aspect, the invention involves a method for customizing an audio portion of a transmitted analog program. The method includes receiving the audio portion of the transmitted analog program. The audio portion includes a first audio signal and a second audio signal. The method further includes receiving information transmitted in a vertical blanking interval of the transmitted analog program. The information includes which of the first audio signal and the second audio signal is replaceable and the replaceable audio signal&#39;s characteristics. The method still further includes interpreting the information and removing the replaceable audio signal, and replacing the replaceable audio signal with a user-selected audio signal. 
         [0011]    In one embodiment the method further includes mixing the user-selected audio signal with the remaining first or second audio signal and transmitting the mixed user-selected audio signal and remaining first or second audio signal to a speaker. 
         [0012]    The foregoing and other objects, aspects, features, and advantages of the invention will become more apparent from the following description and from the claims. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. 
           [0014]      FIG. 1  is an illustrative block diagram of a home entertainment system including a movie playback system, according to one embodiment of the invention. 
           [0015]      FIG. 2  is an illustrative block diagram of the movie playback system shown in  FIG. 1 . 
           [0016]      FIG. 3  is an illustrative example of entries in an audio characteristics table, according to one embodiment of the invention. 
           [0017]      FIG. 4  is an illustrative example of entries in a replacement audio table, according to one embodiment of the invention. 
           [0018]      FIG. 5  is an illustrative example of a program specific information (PSI) table, according to one embodiment of the invention. 
           [0019]      FIG. 6  is an illustrative flowchart of an audio replacement process according to one embodiment of the invention. 
       
    
    
     DESCRIPTION 
       [0020]    The present invention involves a method and apparatus for replacing all or part of an audio soundtrack (e.g., music that is played by default) with other audio that is customized for, or by, the viewer. 
         [0021]    Digital video disks (DVDs) include digital information formatted with MPEG-2 encoding. In MPEG-2 encoding, video data and audio data are separated into different data streams. In the present invention, DVD audio information is encoded such that the musical track is separated from the rest of the audio soundtrack, so that the music, which is prerecorded with video (and is played by default), can be replaced with other music, and thus customized for, or by, the viewer. 
         [0022]    Referring to  FIG. 1 , in one embodiment, a block diagram of a home entertainment system  100  is shown. The home entertainment system  100  includes a receiver  110 , a DVD player  140 , a CD player  135 , a television  125 , four speakers  145   a - d,  and a movie playback system  105 . In other embodiments, other components can be included, such as a CD Juke box, a cable box, or an MP3 player, etc. 
         [0023]    Referring to  FIG. 2 , in one embodiment, a block diagram of the movie playback system  105  is shown. The system  105  includes a receiver interface  255  for receiving a DVD digital audio/video signal  205  (from the digital video disk player  140 , for example), and a separate CD audio signal input  260  (from the compact disk player  135 , for example). In various embodiments, the receiver interface  255  includes various input connectors for connecting to, and receiving signals from the DVD player  140 , CD player  135 , or other digital media players, such as an MP3 player. For example, the connectors can include, banana plug connectors, S-video connectors, BNC connectors, RCA connectors, optical connectors (couplers), or other connectors suitable for audio/video signals. The system  105  also includes an output signal interface  256 , which includes connectors for connecting video signal  250  with a video display, such as a monitor or the television  125 , and connectors for connecting audio signals  245  output from the system with the television  125  or the receiver  110  of the home entertainment system  100 . 
         [0024]    The system  105  further includes a control system  235 , which includes an audio characteristics table  300 , and a memory storage device for temporarily storing (buffering) audio signal data (i.e., audio buffer  265 ). In some embodiments, the control system  235  includes an audio processor, which can be a microprocessor or an ASIC. 
         [0025]    The system  105  still further includes a replacement audio table  220  for storing replacement audio characteristics, and a replacement audio buffer  225  for storing replacement audio, both of which are in communication with the control system  235 . In one embodiment, the replacement audio table  220  and the replacement audio buffer  225  reside in a separate memory (e.g. RAM). In another embodiment, the replacement audio table  220  and the replacement audio buffer  225  reside in memory on the control system  235 . 
         [0026]    The receiver interface  255  communicates or provides digital audio  225  (multiplexed music audio and other (dialog, sound effects, etc.) audio signals or segments), digital data  210 , and digital video  230  to the control system  235 . 
         [0027]    The movie playback system  105  further includes a front key panel (not shown), which enables a user to configure and control the system  105 . In another embodiment, the movie playback system  105  includes, and can be configured and controlled by, an infrared remote control and on-screen menus. 
         [0028]    As previously discussed, the system  105  replaces segments of audio content (MPEG-2 audio packets) from an audio/video presentation being played from the DVD player  140  with replacement audio content (segments). The replacement content may (replacement MPEG-2 audio packets) come from a music CD playing on the CD player  135 , or an MP3 player, or from a separate audio track on the DVD. In another embodiment, music from the CD player  135  or an MP3 player can be stored on the DVD player  140 , if the DVD player  140  has sufficient memory. 
         [0029]    The system  105  includes a graphical user interface (GUI), which is displayed on the television  125 , by the control system  235 , during system  105  configuration. The GUI functions and appears similar to a GUI displayed on a television by a typical VCR, DVD player, or cable set-top box, and is known to those skilled in the art. During normal viewing, the video signal  230  passes through the control system  235  to the video output  250 . During configuration, the GUI is temporarily displayed by the control system  235  in place of the video via the video output  250 . After configuration is completed, the digital video signal  230  again passes through the control system  235  to the video output  250 . 
         [0030]    Prior to playing the presentation (e.g. digital movie), via the GUI, the user is first directed to select the audio content (audio segments of the movie) that is to be replaced. Then the user is directed (by the GUI) to select for each of the selected audio segments of the presentation, the music (replacement audio segments) that he or she would like to have playing in the background of the presentation. For example, the user can choose to change the soundtrack to an entire movie, or the user can change the music for one or more particular scenes of the movie. The user selects the source of the replacement audio content (CD, MP3, DVD, for example), and then selects the particular tracks that are to replace the default (original) audio content. 
         [0031]    Referring to  FIG. 3 , in one embodiment, the control system  235  produces an audio characteristics table  300 , which is not seen by the user, for the audio segments that are to be replaced. The audio characteristics table  300  includes such entries as start time of an audio segment  305 , end time of an audio segment  310 , audio program identifiers (PID)  315 , number of MPEG-2 packets  320 , recommended volume  325 , recommended pitch  330 , recommended tempo  335 , genre  340 , whether the audio segment is an instrumental piece or music with lyrics  345 , whether the audio segment is music alone or music behind dialogue  350 , and a description of the type of scene  355  so the proper audio can be added. The audio PID resides in the header of each MPEG-2 packet and is used to identify the particular MPEG-2 packet. The information used in the audio characteristics table  300  can come from the MPEG private data stream  210  or from private data areas of the existing musical track headers in the audio stream  215 . 
         [0032]    Referring to  FIG. 4 , in one embodiment, after the user has selected the replacement audio segments (replacement MPEG-2 audio packets), the control system  235  produces a replacement audio table  400 , which indicates the audio content from the CD, from another medium, or from another device, that is to be used to replace the selected audio content of the DVD. The replacement audio table  400  includes such entries as start time of the replacement audio segment  405 , end time of the replacement audio segment  410 , replacement audio PID (the same PID as the audio segment to be replaced)  415 , a memory address  420  of the replacement audio segment in the replacement audio buffer  225 , and the device where the replacement audio is stored  425 . The selected replacement audio segments are stored in the replacement audio buffer  225 . The replacement audio segments are identified by their start and end times. Each start/end time is known as a replacement interval. 
         [0033]    Referring to  FIG. 5 , in one embodiment, a program-specific information (PSI) table  500  is shown. The PSI table  500 , which resides on the DVD to be played, is an MPEG-2 construct which serves as a directory  510  of the PIDs program identifiers (PIDs)  505  of the MPEG- 2  packets in the original multiplexed audio stream. When the user initially selects a particular audio segment to be replaced, the corresponding PID of the particular audio segment is stored in the audio characteristics table  300 . The information that characterizes the particular audio segment is later retrieved from the MPEG-2 private data stream  210  or from the private data areas of the existing musical track headers of the particular audio segment in the audio stream  215  during playback. 
         [0034]    In real time, during playback of the presentation (e.g. movie), the system  105  uses the information in the PSI table  500 , the audio characteristics table  300 , and the audio replacement table  400  to remove the audio segment (audio packets) to be replaced by demultiplexing out the particular audio segment (identified by the audio segment PID) from the multiplexed audio stream. The replacement audio segment (with the same PID as the original audio segment) from the CD is then multiplexed into the multiplexed audio stream in place of the original audio segment. 
         [0035]    Referring to  FIG. 6 , in one embodiment, a flowchart of the replacement process is shown. The control system  235  first receives the multiplexed MPEG-2 packets (Step  605 ). The control system  235  then demultiplexes the MPEG-2 audio and data packets (Step  610 ). The control system  235  then determines if a particular packet is a data packet or an audio packet (Step  615 ). If the packet is a data packet, the control system determines if PID of the data packet matches a PID in the audio characteristics table  300  (Step  620 ). If the PID of the data packet does not match a PID in the audio characteristics table  300 , the packet is discarded (Step  625 ). If the PID of the data packet does match a PID in the audio characteristics table  300 , the data is used create the audio characterizing entries in the audio characteristic table  300  for the corresponding audio segment (Step  630 ). 
         [0036]    If the packet is an audio packet, then the audio packet is stored in the audio buffer  265  (Step  635 ). The control system  235  then determines if the audio packet timestamp (point within the movie playback) coincides within a replacement interval specified in the replacement audio table  400  (time period previously selected by the user for replacement with another audio segment) (Step  640 ). Since there may be multiple audio streams during an interval (e.g. one for dialogue and another for background music), the replacement audio table  400  is consulted to determine which stream (as identified by its PID) is to be replaced. If the audio packet timestamp does not coincide within a particular replacement interval, the audio packet in the audio buffer  265  is played (Step  645 ). If the audio packet timestamp does coincide within a particular replacement interval specified in the replacement audio table  400 , the replacement PD is retrieved from the replacement audio table  400  (Step  650 ). Next, the address of replacement audio segment in the replacement audio buffer  225  is retrieved from the replacement audio table  400  (Step  655 ). Thereafter, the replacement audio segment is retrieved from the replacement audio buffer  225  and modified according to the parameters in the audio characteristics table  300  (Step  660 ). The contents of the original (to be replaced) packets in the audio buffer  265  are then replaced with the replacement audio segment (audio packets with the same PID and time interval) that was stored in the replacement audio buffer  225  (Step  665 ). The contents of the audio buffer  265  are then played as if it was the original audio segment (Step  645 ). 
         [0037]    In another embodiment, the present invention involves a method and apparatus for replacing all or part of an analog video&#39;s prerecorded audio soundtrack (e.g., music that is played by default) with other audio that is customized for, or by, the viewer. 
         [0038]    An analog system would require multiple audio tracks, one of which could be replaced (e.g. the music or the dialog in the default language) by user-chosen music or dialogue in another language. For example, in broadcast TV (broadcast analog signal), the transmission spectrum is wide enough to send two audio signals in addition to each video signal (i.e., the bandwidth required for an audio signal is much less than the bandwidth required for a video signal). Information indicating which audio signal is replaceable and the audio signal&#39;s characteristics (music, dialogue, etc.) could be sent with the analog signal in a vertical blanking interval (VBI) of the broadcast signal. The VBI is typically used for sending closed-captioning text information with analog TV broadcasts. The system of present invention interprets the information transmitted in the VBI, removes the default audio, and replaces the default audio with user-selected audio based on the analog system configuration using the methods previously described for replacing digital audio in a digital system. The replacement audio would then be mixed with the other audio track. The combination of the two analog audio signals is transmitted to the analog system speakers. 
         [0039]    Variations, modifications, and other implementations of what is described herein may occur to those of ordinary skill in the art without departing from the spirit and scope of the invention. Accordingly, the invention is not to be defined only by the preceding illustrative description.