WO2005107244A1

WO2005107244A1 - Method and receiver for controlling broadcast data

Info

Publication number: WO2005107244A1
Application number: PCT/IB2005/051320
Authority: WO
Inventors: Eric J. B. Koerber
Original assignee: Koninklijke Philips Electronics NV
Current assignee: Koninklijke Philips NV
Priority date: 2004-04-29
Filing date: 2005-04-22
Publication date: 2005-11-10
Anticipated expiration: 2006-10-29

Abstract

Method and digital receiver for receiving a broadcast data stream. The broadcast data stream comprises audio and video data associated with a sequence of images, an image comprising a scene having one or more objects. An action related to the broadcast data stream is triggered upon detection of an event. An event is detected by evaluating characteristics of the scene, e.g. by evaluating object data in an MPEG-4 data stream, against a set of predefined rules. The set of predefined rules comprises a condition relating to characteristics of the scene or one or more objects in the scene and an associated action.

Description

Method and receiver for controlling broadcast data

FIELD OF THE INVENTION The present invention relates to a method for receiving a broadcast data stream, the broadcast data stream comprising audio and video data associated with a sequence of images, an image comprising a scene having one or more objects, the method comprising triggering of an action related to the broadcast data stream upon detection of an event. In a further aspect, the present invention relates to a digital receiver for receiving a broadcast data stream, comprising processing electronics for retrieving audio and video data from the broadcast data stream associated with a sequence of images, an image comprising a scene having one or more objects, and an application processor connected to the processing < electronics and arranged for triggering of an action related to the broadcast data stream upon detection of an event.

BACKGROUND OF THE INVENTION US patent US-B 1-6,404,977 describes a method and apparatus for use with a VCR (Video Cassette Recorder) to identify selected segments in a broadcast signal in realtime. The segments in the video stream are identified using event markers in the video signal. The segments are, after identification, used for a variety of applications. For example, the invention can be used by a user to personalize a recording of a broadcast by detecting selected segments of the broadcast and suspending recording during unwanted segments, such as commercials. However, this invention relies on broadcast signals that comprise specific signature patterns, inserted at the broadcast source, to enable the identification of segments and trigger predefined actions.

SUMMARY OF THE INVENTION The present invention seeks to provide a method and a receiver for receiving broadcast data which enables the user to define user instructions which are carried out in response to the occurrence of a variety of events, independent from events marked at the data source. According to the present invention, a method is provided according to the preamble defined above, in which an event is detected by evaluating characteristics of the scene against a set of predefined rules (or criteria), the set of predefined rules comprising a condition relating to characteristics of the scene and an associated action. The objects may be abstract entities present in an image sequence, or they may be present as separate data (object data). The evaluation may be performed using image analysis, or using any accompanying meta-data describing the contents of the image as opposed to detecting an event marker in the broadcast data as done in the state of the art. In a further embodiment, the broadcast data stream further comprises object data, such as in MPEG-4 coded audiovisual data streams. Also, further control data may be present, e.g. for identifying different streams in the MPEG-4 coded broadcast data stream. The object data may in an even further embodiment comprise data related to characteristics of one or more objects in a scene, the set of predefined rules comprising a condition relating to characteristics of at least one object and an associated action. This object data, which may comprise spatial information (such as co-ordinates in the image), is usually well suited to use in the definition of event conditions (e.g. a ball being in possession of a particular soccer player). The present invention is advantageously used as part of a multimedia home platform application at the receiver end of a broadcast data stream (e.g. in a digital TV or a set top box). In prior art devices, these kind of applications are used to provide new interactive applications for home entertainment purposes, but so far rely on event markers inserted at the data stream source. With the present invention, a user can modify the set of rules, thus providing far greater flexibility. The action triggered by the present invention may be related to an internal action, i.e. relating to the received broadcast data stream itself. Examples of such actions are zooming in (close up), or selecting a sub stream with e.g. a different camera viewpoint. Also, the action triggered may be an external action, such as the start of recording the data stream on an external recorder, or generation of a warning signal. To allow the user of the present invention to modify the behavior of the reception of broadcast data streams, the method further comprises inputting and storing a set of predefined rules by a user. This allows a very flexible solution, in which the user may define rules, change the rules, etc. In a further aspect, the present invention relates to a software program product, which when loaded onto a processing system arranged for receiving a broadcast data stream, provides the processing system with the capability to execute the method according to the present invention. According to a further aspect of the present invention, a digital receiver is provided according to the preamble defined above, in which the application processor is further arranged for detecting an event by evaluating characteristics of the scene against a set of predefined rules, the set of predefined rules comprising a condition relating to characteristics of the scene and an associated action. The broadcast data stream may further comprise object data (and possibly control data, such as in MPEG-4 coded data streams), the object data comprising data related to characteristics of one or more objects in a scene, and the application processor is further arranged for detecting an event by evaluating the object data against a set of predefined rules, the set of predefined rules comprising a condition relating to characteristics of at least one object and an associated action. In an advantageous embodiment, the digital receiver further comprises storage means connected to the application processor for storing the predefined set of rules. Also, the digital receiver may further comprise a user interface connected to the application processor for modifying the predefined set of rules. The digital receiver according to the present invention may be applied in a number of audiovisual devices, such as, but not limited to a digital TV, a set top box, or a personal video recorder (such as a tape recorder, DVD-recorder or hard disk recorder).

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings, in which: Figure 1 shows a schematic diagram of a receiver according to an embodiment of the present invention. Figure 2 is an illustration in process flowchart form of a method for receiving a broadcast stream in accordance with the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Figure 1 schematically depicts a receiver 1 according to an embodiment of the present invention. The receiver 1 comprises a de-multiplexing means 3 which receives broadcast data from a broadcast source 2. The broadcast source 2 may be the output of a receiver which receives a public television broadcast station or e.g. the output of a home DVD (Digital Versatile Disc) player which produce a stream of broadcast data. The broadcast data in general comprises video and audio data which represent a sequence of images and accompanying sound. The image content (or content of a number of images) forms a scene having one or more objects in it. An object is an entity in a scene which may be processed independently from other objects and the background of an image. The de-multiplexing means 3 receive the broadcast data from the broadcast source 2 and provide audio and video data (and optional object data) of the broadcast data to an AV (audio video) processor 4. The AV processor 4 will process the data for output from the receiver 1, e.g. for presentation on a display or for recording on a video recorder. The person skilled in the art will be familiar with such AV processors, and further detailed discussion of the AV processor 4 is not deemed necessary to explain the present invention. Furthermore, the receiver 1 comprises an application processor 5. The application processor 5 may be a single processor, or a multi-processor arrangement, and in an embodiment, comprises digital processing electronics. The application processor 5 is connected with the AV processor 4 and may be provided with an external control output, e.g. to be able to control a device external to the receiver 1, such as a display or a video recorder. The application processor 5 is connected to storage means 6, such as a disk storage or semiconductor storage, and to a user interface 7. The user interface 7 may be formed by input means such as a keyboard, a mouse or a remote control and output means such as a display. The application processor 5 is arranged to execute a user application, which may be stored in the storage means 6 in the form of a software program. In the embodiment of this invention as depicted in Fig. 1, the application processor 5 only receives object data from the de-multiplexing means 3. Based on a predefined set of rules, which comprise a condition related to the scene (or one or more objects in the scene) and an associated action when such a condition occurs, the application processor 5 is arranged to control the AV processor 4 and/or further external devices. In further conceivable embodiments, the application processor 5 may receive further parts of the broadcast data stream, such as video and/or audio data. The predefined set of rules may be stored in the storage means 6, and the set of rules may be amended or modified by the user by means of the user interface 7. Upon occurrence of a predefined scene characteristic, the application processor 5 will detect that the predefined scene or object characteristic occurs and will provide the corresponding predefined action or user instruction to the AV processor 4 or external device. The application processor 5 may e.g. provide a control signal to a VCR (Video Cassette Recorder) or a DVD (Digital Versatile Disc) recorder upon occurrence of a predefined scene characteristic. For example, in the case of a pre-defined object or scene characteristic, the application processor 5 instructs a VCR to commence recording. Other external devices may include, but are not limited to digital TV, set top box, personal video recorder, digital audio system, etc. The present invention may be advantageously used when the broadcast data stream comprises an MPEG-4 data stream. The MPEG-4 data stream comprises compressed audio and video data, but may also comprise object data. In a single MPEG-4 data stream, also different channels may be present, allowing e.g. to switch from one camera viewpoint image stream to another. In a further embodiment of the present invention, the application processor 5 is running an MHP (Multimedia Home Platform) application which is capable of deciding, based on scene or object characteristics, whether a predefined user instruction should be carried out. In this embodiment, the user has access to the broadcast content with e.g. a Java application. A user may in this embodiment e.g. select an object and store an object related event and an associated action in the set of predefined rules. In an advantageous embodiment of the present invention, the predefined rules may comprise scene characteristic conditions e.g. relating to spatial coordinates of one or* more objects in a scene of the broadcast data. < For example, a scene may comprise a team L, a team R, a ball and lines on a soccer field. Each of the teams L and R consists of 11 objects (an object may itself comprise one or more objects), that are players of the teams L and R. The object data comprises characteristics such as spatial information. If the ball is within a certain pre-defined distance from a pre-defined player, the pre-defined user instruction could e.g. be to zoom in on that particular player. Another example of a user instruction and corresponding object characteristic is to switch to a certain camera angle for viewing if the ball crosses a certain pre-defined line on the soccer field. Note that these scene characteristics relate to the objects in image content as such and are not similar to video segments, which are static parts of the video stream, and scene characteristics do not reveal any (video) information of the image. If the ball is with player 6, then player 6 might be near the goal, or in the middle of the field, leading to two different screen images. Nevertheless, when the predefined set of rules comprises the action to zoom in on player 6 whenever he has the ball, the above situations will both lead to a zoom in action, e.g. by switching to a data stream that shows a close-up view of player 6. Another example relates to motor sports. The traffic light which is used at the start of a race, may be defined as an object in the data stream. The user may set an event in a rule: when the traffic light changes from red to green, one of the possible sub streams, e.g. a certain camera view point, is to be selected. A data stream may, as a further example, be related to a broadcast of a golf tournament. An event may be defined by the user, to record a fragment of the broadcast when the ball speed and direction change when putting is higher than a predefined threshold. Meta events, i.e. events that should be triggered when certain conditions applied to other events occur, may also be defined by a user. For example, when the black ball in a pool game is potted (a spatial or temporal event) within three minutes (the condition on the event), a further event is triggered indicating that player X has won the bet. Furthermore, the present invention does not depend on trigger events that are inserted at the side of the broadcast source in order to personalize broadcast content, and the present invention provides a significant increase in flexibility for the user to personalize broadcast content, if compared to prior art methods. Figure 2 shows a process flowchart of a method for broadcast personalization in accordance with the present invention. The method starts at block 8. At function block 9 the broadcast data is received and at function block 10 the object and scene characteristics are extracted from the broadcast data. In the next function block 11, the object data is evaluated against the predefined set of rules. In function block 12, it is decided whether one (or more) of the pre-defined object or scene characteristics occurs. In case a predefined condition occurs, the corresponding action or predefined user instructions will be carried out as shown in function block 13. In case none of the predefined conditions of the set of predefined rules occur, the method will iteratively return to the beginning of the method at function block 9.

Claims

CLAIMS:

1. Method for receiving a broadcast data stream, the broadcast data stream comprising audio and video data associated with a sequence of images, an image comprising a scene having one or more objects, the method comprising triggering of an action related to the broadcast data stream upon detection of an event, characterized in that an event is detected by evaluating characteristics of the scene against a set of predefined rules, the set of predefined rules comprising a condition relating to characteristics of the scene and an associated action.

2. Method according to claim 1, in which the broadcast data stream further comprises object data, the object data comprising data related to characteristics of one or more objects in a scene, the set of predefined rules comprising a condition relating to characteristics of at least one object and an associated action.

3. Method according to claim 2, in which the object data comprises spatial information.

4. Method according to claim 1, in which the triggering of an action is part of a multimedia home platform application.

5. Method according to claim 1, in which the action is an internal action.

6. Method according to claim 1, in which the action is an external action.

7. Method according to claim 1, further comprising inputting and storing a set of predefined rules by a user.

8. Software program product, which when loaded onto a processing system arranged for receiving a broadcast data stream, provides the processing system with the capability to execute the method according to claim 1.

9. Digital receiver for receiving a broadcast data stream, comprising processing electronics for retrieving audio and video data from the broadcast data stream associated with a sequence of images, an image comprising a scene having one or more objects, and an application processor connected to the processing electronics and arranged for triggering of an action related to the broadcast data stream upon detection of an event, characterized in that the application processor is further arranged for detecting an event by evaluating characteristics of the scene against a set of predefined rules, the set of predefined rules comprising a condition relating to characteristics of the scene and an associated action.

10. Digital receiver according to claim 9, in which the broadcast data stream further comprises object data, the object data comprising data related to characteristics of one or more objects in a scene, and the application processor is further arranged for detecting an event by evaluating the object data against a set of predefined rules, the set of predefined rules comprising a condition relating to characteristics of at least one object and an associated action.

11. Digital receiver according to claim 9, further comprising storage means connected to the application processor for storing the predefined set of rules.

12. Digital receiver according to claim 9, further comprising a user interface connected to the application processor for modifying the predefined set of rules.

13. Digital television comprising a digital receiver according to claim 9.

14. Set top box comprising a digital receiver according to claim 9.