Patent Publication Number: US-9424882-B2

Title: System and method for semantic trick play

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 12/457,428, which was filed Jun. 10, 2009, which claims the benefit of provisional patent application Ser. No. 61/149,220, filed Feb. 2, 2009, the disclosures of which are hereby incorporated by reference in their entireties. 
    
    
     BACKGROUND 
     The present disclosure relates generally to a media system and, more particularly, to a media system for, and method of, semantic trick play. 
     In general, online video on demand (VoD) systems are growing and becoming more accessible (Netflix®, Amazon, Apple TV®). As content libraries grow, a semantic system would be useful and desirable for video systems in order to attract and maintain viewership. A semantic catalogue can help a viewer bridge the gap on plot knowledge and find relevant content across content libraries. 
     SUMMARY 
     According to one aspect, the present invention provides a method of semantic trick play in a media player, including: receiving a semantic trick play command during playback of a current content of a media item; detecting metadata with respect to a current playback position of the media item; determining at least one further playback position in the current content of the media item or a related content in another media item, the further playback position being semantically related to the metadata of the current playback position; and moving playback to the at least one further playback position, so that a media content of the at least one further playback position is then played back by the media player. 
     In the method, the media item may include a video item. 
     The current playback position may include a first scene in a video episode, and the at least one further playback position may comprise a second scene within the video episode, which is semantically and causally linked to the first scene. 
     Alternatively, the current playback position may include a first scene in a first video episode, and the at least one further playback position may comprise a second scene within a second video episode, which is semantically and causally linked to the first scene in the first video episode. 
     According to another aspect of the present invention, a media system for semantic trick play in a video player is provided, including: means for receiving a semantic trick play command from a user while the user is viewing a current content of a video item; means for detecting metadata with respect to a current playback position of the video item; means for determining at least one further playback position in the current content of the video item or a related content in another video item, the further playback position being semantically related to the metadata of the current playback position; and means for moving playback to the at least one further playback position, so that the user views a video content of the at least one further playback position. 
     The present invention also contemplates a computer readable medium including software for instructing a media system to: receive a semantic trick play command from a user while the user is experiencing a current content of a media item; detect metadata with respect to a current playback position of the media item; determine at least one further playback position in the current content of the media item or a related content in another media item, the further playback position being semantically related to the metadata of the current playback position; and move playback to the at least one further playback position, so that the user experiences a media content of the at least one further playback position. 
     The present invention also provides a media system for semantic trick play, including: a media player which detects information regarding a currently viewed first scene of a video content based on a current playback location; a content semantic model which receives the information regarding the currently viewed first video scene and returns to the media player a reference to a second scene within the video content and which is semantically and causally linked to the currently viewed first scene; a content server which receives a request from the media player and then returns to the media player the second scene which is semantically and causally linked to the first scene; and a display device which displays the video content; wherein the media player plays back the second scene on the display device. 
     Those skilled in the art will appreciate the scope of the present invention and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       The accompanying drawings incorporated in and forming a part of this specification illustrate several aspects of the invention, and together with the description serve to explain the principles of the invention. 
         FIG. 1  illustrates a media system according to an exemplary embodiment of the present invention; 
         FIGS. 2A through 2D  depict a broad overview of a semantic rewind operating in the media system of  FIG. 1  according to an illustrative embodiment; 
         FIG. 3  depicts an illustrative embodiment of the media system of  FIG. 1  operating in a content retrieval mode; and 
         FIG. 4  depicts an illustrative embodiment of a method operating in the media system of  FIGS. 1 and 3 . 
     
    
    
     DETAILED DESCRIPTION 
     The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the invention. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the invention and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims. 
     Note that at times the system of the present invention is described as performing a certain function. However, one of ordinary skill in the art would know that the program is what is performing the function rather than the entity of the system itself. 
     Although aspects of one implementation of the present invention are depicted as being stored in memory, one skilled in the art will appreciate that all or part of systems and methods consistent with the present invention may be stored on or read from other computer-readable media, such as secondary storage devices, like hard disks, floppy disks, and CD-ROM, a carrier wave received from a network such as the Internet, or other forms of ROM or RAM either currently known or later developed. Further, although specific components of the system have been described, one skilled in the art will appreciate that a system suitable for use with the methods and systems consistent with the present invention may contain additional or different components. 
       FIG. 1  illustrates a media system according to an exemplary embodiment of the present invention. In general, the media system for semantic trick play  10  includes an input device  12 , such as but not limited to a keyboard, keypad, or remote control for operation by an associated user  14 , and a media playback system  16 . In this exemplary embodiment, the media playback system  16  includes a media player  18  and a display device  20 . 
     The media player  18  may be, for example, a personal computer, a set-top box (STB) for playing digital television content received from a television content provider, a Digital Video Recorder (DVR) for playing previously recorded video content such as previously recorded television content received from a television content provider, an Apple TV® device for playing downloaded content that has been purchased or rented from a remote media distribution service such as the Apple® iTunes® store, a Digital Versatile Disc (DVD) player, or the like. The media player  18  may be connected to the display device  20  via any desired audio/video connection such as, for example, a High Definition Multimedia Interface (HDMI) connection, a Digital Video Interface (DVI) connection, a coaxial cable connection, or the like. The display device  20  may be, for example, a computer display screen, a television (TV), or the like. In an alternative embodiment, the display device  20  may be incorporated into the media player  18 . 
     The media player  18  includes a media playback function  24  and a semantic trick play function  26 , each of which may be implemented in software, hardware, or a combination thereof. The media playback function  24  generally operates to provide playback of media items obtained from a content source or server  28 . In the exemplary embodiment, the media items are video items. As such, the media playback function  24  provides playback of the video items and presentation of the video items to the user  14  via the display device  20 . The content server  28  varies depending on the particular implementation of the media player  18 . For example, if the media player  18  is an STB, then the content server  28  may be a television content distribution network such as a Cable Television (CATV) network. As another example, if the media player  18  is a DVD player, then the content server  28  is a DVD. As a further example, if the media player  18  is a device such as an Apple TV® device, then the content server  28  may be a remote media distribution service such as the Apple® iTunes® store, where the media player  18  has access to the remote media distribution service via a network such as, for example, the Internet. 
     The following is a more detailed description of the semantic trick play consistent with the present invention. 
     The semantic relationships between plot elements across one piece of content or various pieces of content may be established using various techniques, including, but not limited to, one of the following exemplary techniques: user community networks (for example, The Internet Movie Database (IMDb)), by a content provider, or semantic analysis/indexing and retrieval of video/storyline detection. 
     There are currently many active user community networks around popular video content. Such a user community may create the relationships using: a wiki-model where multiple contributors refine semantic relationships in the process of creating annotations and other useful content related to the video content. Alternatively, a DVR interface may be used where the semantic relationships can be created by individual users and aggregated by a service using the DVR, while watching the content. 
     When provided by the content provider, the MPEG-7 standard allows for annotations to be bundled along with the original piece of content. The semantic relationships or references to semantic relationships can be encoded in MPEG-7 by the content provider. 
     With respect to semantic analysis, indexing and retrieval of video, and storyline detection, these techniques leverage various techniques in, for example but not limited to, video analysis of visual effects, speech and audio effects, object and facial recognition, natural language processing and semantic analysis using speech recognition, ontologies, machine learning, information indexing and retrieval and semantic or ontological querying. 
     Moreover, performing metadata analysis on a particular scene of a video contemplates metadata that may include, but is not limited to, at least one of: descriptions of a video scene, actual and/or fictional names of characters in a video scene, data structures establishing semantic links between two or more video scenes, or indexes that allow semantic linking and retrieval. 
     Moreover, for each video scene or segment, the metadata information identifying and describing the segment may include information describing the content of the segment of the media item. For example, the information may describe the segment as containing an action scene, a romantic scene, or the like. As another example, if the media item is one of the Star Wars movies, the information may describe the content of the segment more specifically as containing a Princess Leia scene, a Darth Vader scene, a droid scene, a space-fighting scene, or the like. As another example, the information describing the segment may include a list of actors or actresses appearing in the segment and/or a description of activities that take place in the segment. The information describing the content of the segments of the media item may be information provided by a producer or creator of the media item, information such as annotations provided by one or more users that have previously viewed the media item, or the like, or any combination thereof. 
     Also consistent with the present invention, the metadata may be, for example, tags, annotations, a script or lyrics for the media item, closed-captioning information, sub-titles, or the like. Moreover, the semantic trick play function  26  may also utilize a combination of audio and video frame analysis techniques. For example, to detect violent content, in addition to frame analysis techniques to detect, for example, smoke or blood pixels, the system may also utilize audio analysis techniques, for example, to detect gunshot sounds. 
     For utilizing semantic trick play across episodes, a content library is provided to be available to the DVR (see, for example, content server  28  in  FIGS. 1 and 3 ). The content library can be a local library (such as iTunes®/Apple TV®) or at some remote content library source (such as cable VoD or Netflix®). 
     An explanation of some of the terms and functions will now be provided in the context of the present invention. Content semantic relationships may span across episodes, movies or genres, various multimedia content types, and result in a semantic content tree, which is navigable by the media system for semantic trick play  10  making requests for semantic trick play functions. While the present invention refers to a semantic content tree, other semantic content relationships are contemplated and may also resemble graph structures other than a tree. Thus, in semantic content trees, nodes have a single parent node, which implies that a single event in a plot leads to a single consequence, or conversely a single event may have only a single cause. If the plot is linear (which is the typical case), the semantic structure would resemble a tree, but in case of non-linear or complex plots, the relationship structure can adopt a correspondingly complex shape. For instance, a single plot event may cause multiple, mutually-unrelated events down the line, in which case, the relationship structure would look like, for example, a web of interleaved trees rather than a single tree. Another case is where a single content item has multiple plot-lines (e.g., a soap, etc.). 
     These semantic relationships are stored in a remote server, such as the content server  28 , or downloaded to the local playback device, such as the media player  18 . 
     Forward and backward references in the semantic content tree generally represent moving back and forth in plot lines, episodes or story lines. 
     The term “trick play” generally refers to using the transport or viewing controls such as pause, instant replay, rewind, etc., of the media player  18  (for example, a DVR system). Embodiments commensurate with the present invention relate to a semantic based trick play system, such that an additional set of trick play controls is also available which is based on semantics instead of time. 
     Semantic trick play functions are implemented, for example, in software and have the following functionality:
     Semantic Rewind—When a user selects semantic rewind: (1) the current video pauses; (2) the media player  18  (e.g., DVR or playback unit) fetches the semantic tree for this video segment or scene; (3) a selection is made from the semantic tree; (4) the DVR looks back semantically to the referred video segment; (5) the DVR fetches the video segment, and the current segment location is stored for later reference; (6) the DVR starts playing the fetched video segment; and (7) at the conclusion of playing, the user may either hit semantic rewind again, and go back to step (1), or do nothing, and the system continues playback on the previous video.   Semantic Fast Forward—This function is similar to Semantic Rewind, except the system moves forward in the semantic tree.   Semantic Play/Pause—This function executes play and pause on the current video clip.   Semantic Unwind (or Resume)—This function serves to unwind all trick play functions and return to the original video clip and the position in which the semantic trick play was initially invoked.   

     The semantic trick play functionality will be discussed in more detail later on in connection with  FIGS. 1, 3 and 4 . 
       FIGS. 2A through 20  show a broad overview of a semantic rewind consistent with an exemplary embodiment of the present invention. On the far right in  FIG. 2A , a user  14  is viewing an episode of “The Office” (Episode  34 ). The user has missed a few episodes and is not aware of plot subtleties. In one such scene during Episode  34 , the user  14  does not understand a plot element and hits “semantic rewind”, for example, a button  32  on the input device  12 . As shown in  FIG. 28 , the user  14  is taken back to a previous scene in Episode  25  which explains the reference. As further shown in  FIGS. 2C and 20 , the user  14  continues to hit the semantic rewind button  32  and the system continues to take him back to the various connected plot elements in Episodes  21  and  15 . 
     Similarly, the user  14  may hit a “semantic fast forward”, for example, a button  34  on the input device  12  (see  FIG. 1 ), and the system  1 O would take him forward to follow the current plot element. While the broad overview above shows an example regarding various episodes, the semantic trick play consistent with the present invention can be across one piece of content, as well as various episodes. 
       FIG. 3  depicts an illustrative embodiment of the media system of  FIG. 1  operating in a content retrieval mode, whereas  FIG. 4  depicts an illustrative embodiment of a method operating in the media system of  FIGS. 1 and 3   
     With reference to  FIGS. 1, 3 and 4 , in step S 100 , a user  14  is watching video content (e.g., playing Episode  5 , scene  2 ) on the media player  18 , such as a DVR. The user  14  executes a semantic rewind by pressing the semantic rewind button  32  on the input device  12  (step S 102 ). 
     In step S 104 , the DVR passes the current scene information to the content semantic module  30 . While the content semantic module  30  is shown as a separate unit in  FIGS. 1 and 3 , the content semantic module  30  can be hosted locally on the media player (e.g., DVR)  18 , or on a remote system. 
     The content semantic module  30  returns a backward reference to the current scene and plot element (step S 106 ). In  FIG. 3 , as an example, Episode  1 , scene  3 , is returned by the semantic module  30 . 
     In step S 108 , the DVR  18  requests the scene from the content library, which may be content server  28  (i.e., a request is made to fetch Episode  1 , scene  3 , from the content server  28 ). 
     Finally, in step S 110 , the scene is returned and the content is played for the user  14  on the DVR  18  by the semantic trick play function  26  (i.e., the Episode  1 , scene  3  clip is returned and then played for the user  14 ). The user  14  can play or pause the returned scene by hitting the semantic play/pause button  38  on the input device  12 . Accordingly, the user  14  is able to play back the scene from an earlier episode which is related in some fashion to the episode and scene he was originally watching. Similarly, for executing a semantic fast forward, the media player  18  passes the current scene information to the content semantic module  30 , and the semantic module  30  returns to the media player  18  a forward reference to the current scene. The media player  18  requests the returned reference from the content server  28 . The scene is returned and the content is played on the media player  18 . 
     Example 1 
     Semantic Rewind Across Multiple Videos 
     Richard is a spotty watcher of “The Office” from NBC. During one particular scene, he hears Michael Scott use the words “Dinka Flicka”. He does not understand the reference, because he has missed so many episodes, so he hits the “Semantic Rewind” button  32 . His DVR fetches a scene from an episode from last season where Darryl, from the warehouse, teaches Michael fake urban slang. Richard understands and is happy. 
     Example 2 
     Semantic Rewind within Same Video 
     Cathy is watching an old MacGyver episode on ABC.com. She gets confused at one point as the plot does not make sense and asks “How the heck??” and presses the “Semantic Rewind” button  32  on input device  12 . The media player  18  performs metadata analysis on the current scene and finds the metadata “ingenious use, do-not-try-this-at-home, stapler, rubber band, grappling hook”. The player searches the indexed metadata of previous scenes and finds one with the metadata “surreptitious, hide, rubber band, stapler, plot device”, and identifies this scene as a potential solution. 
     Alternatively, prior analysis has been performed on this video, either by machine or human users, and a semantic link graph is embedded in the metadata layer (MPEG 7) which links these two scenes. The media player  18  simply traverses this graph for a semantic rewind. The media player  18  rewinds to that scene. 
     Cathy watches the scene closely this time. She notices him slip a rubber band and a stapler in his coat pocket, and finally understands how he was able to build a grappling hook launcher to pull himself out of the mine shaft. 
     She presses “Semantic Unwind” button  36  and jumps back to her previous position. She then gets a call that she has to take, and cannot watch the full episode, so she double taps the “Semantic Fast Forward” button  34 . This takes her to the climactic scene where the entire plot is resolved. She stops watching the video and takes the call 
     A further description of how semantic relevance is established will not be described. 
     When a user invokes a semantic trick play function, the system  10  has to determine what is semantically relevant at that point in playback. There may be several interesting semantic items, which may be identified using various techniques already discussed. Each of these semantic items will take different paths through the semantic content tree. The system  10  thus determines which of these semantic paths to take using any combination of the following techniques:
         1) As instructed by the content provider/producer, the content producer instructs the system as to what is semantically relevant during which video segments/scenes/clips.   2) By user community: either implicitly or explicitly, the user community votes on what is most relevant. “Implicit” refers to, for example, a semantic path that users have taken in the past or a historical selection. It can also refer to a historical path related to the current video content or the current location within the video. “Explicit” refers to a situation where a user obtains multiple options and then the user makes the choice and selects his choice by, for example, pressing a button.   3) By querying the user: upon involving semantic trick play, the system displays to the user the semantically relevant points in the current video segment or time, and the user selects which is most relevant to him.   4) User history and profile: the system makes a calculated judgment about what is most relevant to the user, using history of previous selections or the user profile.       

     In the exemplary embodiment, establishing semantic relevance may include Causal Graphs or Causal Networks. A Causal Graph, as used herein, describes the causal relationship between two states or events, e.g., event E 1  “causes” or “enables” or “leads to” event E 2 , or state S 1  is “changed by” event E 1  to state S 2 . 
     For instance, at a high level, E 1  may describe scene S 1 , where “MacGyver steals a rubber band and a stapler”, and E 2  may describe S 2 , where “MacGyver builds a grappling hook out of a rubber band and a stapler”, and hence there is a causal “enables” relationship between E 1  and E 2 , and by extension, scenes S 1  and S 2 . A Semantic Rewind operation on a scene S 2  described by E 2  would travel this causal relationship backwards to accurately identify scene S 1  described by E 1  that enables it. 
     Thus, in the present invention, the semantic trick play operation should not take the user to a scene with similar semantic/ontological nodes but absolutely no causal relationship. For instance, a rewind on scene S 1  where MacGyver steals a stapler and a rubber band, tagged with semantic nodes [“MacGyver”, “stapler”, “rubber band”], should not take the viewer to an unrelated scene S 3  where MacGyver uses a stapler to staple a bunch of forms and bundles them up using a rubber band, which also happens to be tagged with semantic nodes [“MacGyver”, “stapler”, “rubber band”]. Instead, and unlike previous solutions that do not consider causality, in the present invention, the Semantic Rewind on scene S 1  takes the user to the related scene S 2   
     Constructing such data structures through automated video analysis may be accomplished using techniques in the fields of artificial intelligence (AI), Machine Learning and Natural Language Processing, and are thus contemplated by this invention. For the purposes of this invention, however, such Causal Networks also may be created manually by human operators or user created links. 
     In addition, techniques employing probabilistic approaches and heuristics may also be applied. 
     For instance, a scene S 1  tagged (either automatically or manually) with [“MacGyver”, “steals”, “stapler”, “rubber band”] would have a high correlation with a scene S 2  tagged with [“MacGyver”, “uses”, “stapler”, “rubber band” “builds”, “grappling hook”] simply because they share a large number of tags, and hence there is a high chance they are causally related. Furthermore, the fact that scene S 1  occurs before S 2  (comparing temporal locations) indicates that S 1  probably causes S 2 , i.e., the causal relationship can be described as:
         S 1  - - - - [leads to]- - - - &gt;S 2 .
 
Such simple probabilistic models may lead to a large number of relevant causal relationships, which can be further filtered and/or enhanced using heuristics. For example, S 1  and S 2  occur in the same episode, which gives the causal relationship higher probability of being accurate as opposed to, for example, a link between S 1  and S 3 , or S 2  and S 3 , where S 3  occurs in a different episode. As another example, the tag “MacGyver” shows up in 90% of all scenes, which implies that it is a primary focus of this video. Hence when comparing tags and identifying relevant videos, that tag is given lower weight, that is, if two scenes only have that one tag “MacGyver” in common, they are not deemed to be especially relevant to each other.
       

     Note that the tags do not have to explicitly name the objects or actions they refer to, but they may just identify common objects using video object recognition, i.e., [“MacGyver”, “rubber band”, “stapler”] may simply be identified as objects [“P 1 ”, “ 02 ”, “ 03 ”] and those same objects showing up in both scenes would lead to both scenes having the same tags. Video object recognition and object identification per se are well known in computer vision art. 
     The present invention has substantial opportunity for variation without departing from the spirit or scope of the present invention. For example, while the embodiments discussed herein are directed to personal or in-home playback, the present invention is not limited thereto. Further, while the examples refer to video segments or scenes, the present invention is not limited thereto and other forms of media content are contemplated herein. 
     Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present invention. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow.