PLAYBACK OF INTERACTIVE PROGRAMS

Abstract: A method for playing back a program which includes one or more interactive applications. A program which is stored, either in the form of a data stream or as a set of files is played back from a storage device. When playback is started, applications which are detected are launched. Applications are detected in the playback of pushed content when they become available in the playback stream. Applications are detected in the playback of pulled content by comparing the validity ranges of the applications to a current playback index. When special playback modes are used, signals which affect the lifecycle of an application are detected and corresponding signals are generated to maintain the proper state of the application. During these special playback modes, these various notification signals may be conveyed to applications which are configured to operate during these modes. Applications which are not configured to operate during these special playback modes may be terminated when the special modes are initiated and restarted when the special modes end.

Description: I I I LI : PL VY1JΛ( k OF IN I ERA( 1 I\ F PROGRAMS BACKGROUND OF THE INVENTION 1 I leld of the Invention The invention relates generally to broadcast television systems and more particularly to a system and method for playing back programs which have been stored on the storage device of an interactive television system receiver, w herein the programs contain one or more interactive applications 2 Description of Related Art Interactive television systems provide a means to deliver interactive content as well as ordinary television audio and video to a large number of subscribers Programs broadcast by these systems may incorporate television audio and video, still images, text, interactive graphics and applications, and many other components The interactive content of the mteractive television signal may therefore include application code, data associated with the audio and video, control signals, raw data and many other types of information Interactive content such as application code or information relating to television programs is usually broadcast in a repeating format In other words, each piece of information is broadcast a first time, then each is transmitted a second time, and so on The cycle is repeated so that each piece of interactive data is transmitted, for example, every ten seconds The pieces of information which are broadcast in this manner form what is referred to as a "carousel " The sequence of mformation that makes up the carousel can be prepared m advance, or it can be determined "on the fly " Broadcast systems (e g , mteractive television systems) transmit information m a carousel format in order to allow receivers in the system to selectively obtam particular pieces of information in the carousel without requiring a return path from the receivers to the server If a particular receiver needs a particular piece of mformation, it can simply wait until next time that piece of mformation is broadcast to obtam the mformation If the mformation were not cyclically broadcast, the receiver would have to transmit a request for the information to the server, thus requiring a return path Other receivers in the system can operate in the same manner, each receiver waitmg for the mformation it needs, and then usmg only that mformation By employmg carousels to broadcast information, the system eliminates the need to connect each of the receivers with the server and further eliminates the need for the server to process individual requests for mformation Generally, a broadcast signal may include a number of programs which in turn may include a number of audio/video streams and/or data streams Data streams may be used to carry data such as interactive application data, subtitle information, or other data The pieces of information, or data objects, m a carousel are often intended to be combined to form a single program This program may also contain streaming data such as audio or video For example, an mteractive television game show may combme television audio and video with interactive content such as application code which allows users to answer questions Another example would be a news program which combines audio and video with application code that inserts current stock prices m a banner at the bottom of the screen It is to be understood that the term "program" as used herein refers to any broadcast material including television shows, sporting events new s programs movies or anv other tvpe of broadcast material or segment of the show event program movie or other material The program may include onlv audio video data or anv combination thereof The program may be only a portion of a television show or broadcast (e g , without commercials, or missing a portion of the beginning or end) or may be more than one show, or include commercials for example Program content received in a broadcast system is normally intended to be consumed immediately It is nevertheless possible to record this content for later playback The broadcast information can be recorded as is" (1 e , as the stream of data transmitted to the receiver ) or it may be recorded as a set of files that can be accessed randomly instead of sequentially If the information is recorded as a data stream, the data may be referred to as "pushed" data since the receiver must play the information back as a data stream — it cannot retrieve particular data objects out of order Data objects which are recorded as a set of files can be individually retrieved, and may therefore be referred to as "pulled" data Regardless of whether an interactive program is stored as pushed content or pulled content, there may be difficulties m playmg back the recorded program, since it was originally intended for immediate consumption Although it may be a relatively simple matter to play back the entire program from start to finish, just as it was originally provided to a user, the user may wish to use a special mode, such as pausmg, fast- forwarding, reversing, or jumping to particular pomts m the program when it is replayed Because the program may mclude different mteractive applications which are m various states throughout the program, it is necessary to mamtain the proper states for these applications, even when parts of the program are skipped m special playback modes Further, the applications may interact with other data objects, so m a special playback mode it may be necessary to generate signals that would not otherwise be generated SUMMARY OF THE INVENTION One or more of the problems outlined above may be solved by vanous embodiments of the invention One embodiment compπses an mteractive television receiver which is coupled to a storage device The receiver is coupled to a broadcast network and configured to receive a signal correspondmg to a program The signal contams pushed mteractive television data The receiver is configured to store the pushed data, either as pushed content or as pulled content, on the storage device When the program is played back from the storage device, the receiver is configured to launch applications which are detected m the program If the program is stored as a stream of data, an application may be detected by receiving an indication that it is available If the program is stored as a set of files, an application may be detected by comparmg the validity range of the application to a current playback index for the program If special playback modes are used, the receiver is configured to determine whether the program would generate signals during the portion of the program skipped during special mode operations and to generate correspondmg notifications if necessary The receiver may also be configured to terminate and restart applications which are not configured to operate in special playback modes One embodiment compnses a method for playing back a program which includes one or more interactive applications A program is stored, either in the form of a data stream or as a set of files containing the data objects which make up the program When playback is started, applications which are detected are launched Applications are detected in the playback of pushed content when they become available in the playback stream Applications are detected in the playback of pulled content by compaπng the validity ranges of the applications to a current plavback index W hen special playback modes aie used signals winch af fect the lifecycle of an application are detected and corresponding signals aie generated to notify the application to allow it to maintain its proper state During these special playback modes, these various notification signals may be conveyed to applications which are configured to operate during these modes Applications which are not configured to operate during these special playback modes mav be terminated when the special modes are initiated and restarted when the special modes end BRIEF DESCRIPTION OF THE DKA WINGS Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the accompanying drawings in which Fig 1 is a functional block diagram of an interactive television system Fig 2 is a diagram illustrating the structure of a carousel and a correspondmg data stream Fig 3 is a diagram illustrating the interrelation of data objects in one program Fig 4 is a flow diagram illustrating one embodiment of the present method Fig 5 is a flow diagram illustrating an embodiment of the present method in which a program has been stored in a data stream Fig 6 is a flow diagram illustrating an embodiment of the present method m which a program has been stored as a set of files While the mvention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example m the drawings and will herem be descπbed m detail It should be understood, however, that the drawings and detailed description thereto are not mtended to limit the mvention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present mvention as defined by the appended claims DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Broadly speaking, the mvention compπses an improved system and method for replaying stored mteractive programs, wherein the programs are originally mtended to be consumed as pushed broadcast data While many embodiments of the mvention are possible, the following description focuses primarily on one embodiment which is implemented m an interactive television system This description is mtended to be illustrative rather than limiting Referring to Fig 1, a functional block diagram of an mteractive television system 10 is shown Interactive television system 10 generally compπses a broadcast station 12 and a receiving station 14 coupled to the broadcast station by a broadcast medium 13 In this figure, broadcast medium 13 is depicted as a satellite transmission network The broadcast medium may, m other embodiments, comprise other transmission means such as cable, telco, MMDS (microwave) and terrestrial transmission media Broadcast station 12 is coupled to a program source 15 which is configured to provide the data which forms the program Receiving station 14 mcludes a receiver 18 which is coupled to a storage device 16 Storage device 16 is configured to store the program data Receiving station 14 also includes a television 17 which is used to present the program to a user In one embodiment, the data objects of a program hich is to be broadcast from broadcast station 12 to receiving station 14 are stored in one or more program sources 15 The data objects may be stored separately (e g , as independently accessible f iles ) or thcv may be stored as a pi cconstiucted data sticam It should be noted that tin. program may also contain streams of data (e g , audio and video) which ai e not transmitted as data ob|ects If the data objects of the program are stored as individual files they are retrieved by broadcast station 12 from program source 15 to be sequentially broadcast If the program is stored as a preconstructed data stream, the stream can be broadcast essentially as it is stored The program data may be compressed and control information may be added to the data for use by the interactive television system The program data and any additional information is then converted by broadcast station 12 to a format suitable for transmission over broadcast medium 11 In this particular embodiment, the data is formatted into packets which can be transmitted over a digital satellite network These packets may be multiplexed with other packets for transmission Broadcast station 12 transmits the data objects of the program in a carousel which is cyclically transmitted to receiving station 14 This produces a stream of data m which each data object is transmitted repeatedly It should be noted that the broadcast medium (a digital satellite network in this embodiment) can support a number of different channels, and that different carousels (and corresponding data streams) can be concuπently broadcast on these channels When receiving station 14 receives the data stream, the program contained in the data stream may be played immediately or it may be recorded If the program is to be played immediately, receiving station 14 converts the data stream back mto the data objects and uses them as necessary in the program If the program is to be stored, it may be parsed mto the individual data objects and stored as a set of files, or it may be stored as a data stream, as it was received If the program is to be stored, it is conveyed to storage device 16 Data streams which are included in the program (e g , audio or video streams) may also be stored on storage device 16 The program may be stored whether it is immediately played or not Receiver 18 is typically implemented m a set-top box which is connected to television 17 The set-top box incorporates a control unit (e g , a microprocessor,) a memory, and other components which are necessary to select and decode the received mteractive television signals Because the basic components and features of set-top boxes are known, they will not be discussed in detail here Typically, set-top boxes are designed to provide the necessary interactive functionality at a mmimal cost Consequently, they normally have a limited amount of memory and no storage devices (e g , hard disk drives ) While the memory is sufficient to execute mteractive applications, it is not adequate to store the applications for an indefinite penod of time Therefore, the applications do not normally remain m memory when they are no longer bemg executed Even if the memory of the set-top box were large enough to store some mteractive applications, it might still be too small to accommodate a program which includes large amounts of audio or video data, application code, or other mformation In one embodiment of the present system, storage device 16 is coupled to the set-top box to provide sufficient storage to record programs that will not fit in the limited amount of memory in the set-top box Storage device 16 may compπse any suitable storage device, such as a hard disk drive, a recordable DVD drive or optical disk drive It can be internal to the set-top box, or it may be connected externally Storage device 16 can be connected permanently or removably to the set-top box Referπng to Fig 2, the structure of a carousel (and a coπesponding data stream) which is transmitted to the receiver is illustrated Carousel 24 compπses data objects 21-23 and carousel information 20 Data objects 21- 23 are retrieved from a program source as described above Carousel information 20 is provided by the broadcast station and may contain mformation such as the carousel ID and version number, a file access table or directory for the carousel and various other information (Portions of this information such as the file access table are not necessary in programs which are intended for immediate consumption ) T e broadcast station transmits carousel information 20 and data objects 21 -23 sequentially The first instance of the transmission of carousel 24 is indicated by 25 Alter the broadcast station has completed transmission of the first instance of carousel 24, it is transmitted again, as indicated by 26 The successive, cyclical transmissions of carousel 24 indicated by 25-29 form data stream 30 Transmission of the carousel may be repeated indefinitely As mentioned above, the data objects which comprise a program may include application code, audio and video data, control signals, raw data and other types of information If the program is to be immediately consumed (l e , presented to the user,) the data must be parsed to extract the data objects from the stream When the necessary data objects have been extracted, the program is played The data objects are used as defined in the program For example, any applications which need to be executed are launched, any audio or video data which needs to be presented to the user is played or displayed, any signals which need to be produced are generated, and so on The program is presented to the user, typically via a television 17, and is consumed Regardless of whether or not the program is immediately presented to the user, it can also be stored The storage device can be used to store programs "as is" (l e , as a data stream which is essentially the same as that received m the broadcast signal) or as a set of files that can be individually accessed or updated In either case, the recorded program can be played back The present system and method are employed to facilitate and/or enable the use of playback features such as tnck play modes when viewmg the recorded program To illustrate the advantages of the system and method, it may be useful to examine the structure of a program As noted above, a program may consist of a number of data objects and data streams These data objects may reference each other, they may trigger certain events, or they may be tπggered by certain events Interactive applications which are contained m the program may be started and stopped while the program is bemg played If the data objects are stored as files, the validity ranges associated with the files correspond to the times during which they are available to the program For example, as long as a data object is being broadcast as part of a carousel, that data object is valid When the carousel (hence the data object) is no longer bemg broadcast, the data object is no longer valid Thus, a start time and an end time defining the validity range of the data object can be determined by the receiver and stored with the correspondmg file It should be noted that, although the present disclosure is directed pπmaπly to an mteractive television system which is configured to play back a previously stored broadcast program, the system and method presented herem are equally applicable to the playback of programs which are stored by other means For example, pushed content which could be broadcast may also be stored offline (e g , on a DVD) and later distributed to the user for playback The program could also be played back from an on-demand server (e g , playing video on demand ) Referring to Fig 4, a flow diagram illustrating one method employed by the mteractive television system descnbed above is shown After the program is recorded on the storage device, playback of the program is initiated The receiver is configured to detect applications in the recorded data When an application is detected in the program, the application is launched The manner in which applications are detected in the program depends upon how the program was stored Refernng to Fig 5, a flow diagram illustrating the detection of an application in a system configured to receive a program as a data stream is shown If the application was recorded as a data stream, the receiver detects an application by examining the sequential stream of data which is plaved back from the storage device When th stream contains information indicating that the application is available, the receiver detects this information and thereby detects the application The application is then launched Referring to Fig 6, a flow diagram illustrating the detection ol an application in a system configured to receive a program as a set of files is shown. If the program was recorded as a set of files, the detection of applications in the program proceeds in a different manner When playback of the program is initiated, the receivci examines the stored files. In one embodiment, the application files include information defining validity ranges for the corresponding applications. The receiver compares the validity range for each application to a current playback index. If the current playback index falls within the validity range of a particular application, that application is considered to have been detected, and is launched. The current playback index mentioned above is simply a relative time index used in the playback of the program. The validity ranges mentioned above comprise data which, in one embodiment, is determined by the receiver when the program is recorded. (It should be noted that in some embodiments, particularly those in which the program is played back from a prerecorded medium such as a DVD, the validity range may be predetermined and provided with the corresponding data object.) The validity range consists of a beginning time and an end time. The application is intended to be executed (or to be available for execution) between the beginning and end times. Thus, if playback of a program is initiated and the current playback index is within the validity range of an application, the receiver will launch the application. This may be illustrated m the following example. Assume a program is broadcast from 1 :00 to 2:00. The program contains an application which is valid durmg the entire program. If a user records the program from 1 :30 to 2:30, the application is stored with a validity range from 1 :30 to 2:00, or 30 minutes from the beginning of the recording. When the program is played back, the application will be valid for the first 30 minutes of the recording. If the user starts playback of the program and fast- forwards for 40 minutes, when normal playback is resumed, the application will no longer be valid and will not be restarted. Whether the program was stored as a data stream or as a set of files, the detection of applications continues as the program is played back. Thus, as new applications are detected, they are launched. It should be noted that the capabilities of the receiver and the policies implemented in the execution environment of the receiver determine the effect on a currently executing application of launching another application. If the receiver is capable of executing only one application at a time, a currently executing application may have to be killed or suspended before another application can be launched. It may or may not be necessary to unload the first application from memory while the second application is executing. If the receiver can simultaneously execute more than one application, then the second application may be launched while the first application continues to run. The receiver may, however, implement a policy which prohibits executing applications simultaneously. The receiver may therefore be required to kill or suspend the first application upon launching the second, even though the receiver is capable of executing both. As mentioned above, when a user plays back a program, he or she may wish to use special playback modes rather than simply playing the program back sequentially (i.e., in a normal play mode.) The special modes may include trick play modes, such as fast forward, slow motion and rewind, and may also include jump, seek and pause features. When special play modes are used, the program moves from a first point at which an application is in a first state (c g exccutinn ) to a second point at which the application should be in a second stale ( e g terminated or suspended ) Because the portion of the program between the fust and second points is not played (or executed,) certain signals and events which would normally cause an application to modify its state are not encountered Care must therefore be taken to ensure that the lifecycle of the application resulting Irom use of the special play mode corresponds to the position in the program after the special play mode is stopped ("Lifecycle" is used here to indicate the state of the application including but not limited to states ol execution, such as launch, suspend resume and terminate, and any internal states defined by the application duπng execution ) Because the application may skip an event (a signal or set of conditions) which should rπgger a change of state in the application it may be necessary to take some action to produce the change of state In one embodiment, the receiver is configured to determine whether any events would occur between initiation of the special play mode and termination of the special play mode which would affect the lifecycle of the application These events may include the receipt of particular signals or notifications, the existence of particular conditions, or other factors The receiver is configured to generate signals or notifications correspondmg to the skipped events, and to convey these signals or notifications to the application to modify its state These signals and notifications may include kill signals, notifications that special play modes have been started or stopped, notifications that seeks have been initiated, module or tπgger notifications, accelerated version notifications, and other signals or notifications that may be useful m playing back the program It should be noted that the generation of signals and notifications may be dependent upon the existence of related conditions For example, modules and triggers may be flagged to mdicate whether notifications relatmg thereto should be provided to the applications Generation of signals and notifications may also be conditioned upon whether they occur within a correspondmg validity range The receiver is also configured to generate signals associated with application chaining and to provide the signals to applications in the program "Chaining" refers to the execution of different applications m the program m relation to each other The chaining policy defines how execution of certain applications affects other applications For example, if a first application is currently executmg and a second application is detected and launched, the chammg policy may define whether the first application is terminated or suspended or, if the receiver can concurrently execute both applications, whether they should both be executed at the same time It should be noted that the capabilities of the receiver may affect the chammg policy, smce the policy is implemented m the receiver (For example, if the receiver can only execute one application at time, the chammg policy cannot have two applications executmg concurrently ) The signals provided by the receiver to the applications are typically generated sequentially (in the order they would have occurred in a normal playback mode) because the state of an application may depend on the order m which the signals are received When the special play mode is a forward mode (e g , fast forward,) the signals and notifications generated by the receiver are provided to the applications in their normal sequential order When the special play mode is a reverse mode (e g , rewind,) the signals may have to be generated in reverse order, or the receiver may have to generate signals which "undo," or reverse the effect of, the forward-play signals It should be pointed out that some applications may depend on live data reception to maintain their state When a special playback mode is used to cause an application to move to a particular pomt in the playback of the program, precautions may need to be taken to ensure that the application is in the appropriate state after the program returns to a normal playback mode This needs to be addressed for two different cases cases in which applications were authored with the intent that they would be recorded and played back; and cases in which applications were not intended to the recorded and replayed. In the first case, an application is produced with the knowledge that it maybe recorded and played back using special play modes. Such an application would typically be designed to accept notifications of these special play modes and to accommodate them. For example, an application can be configured to generate a query to determine the current position in the playback of the program. The application could then set its internal state according to the position in the program. In the second case, an application is produced with the intent that it will be consumed as it is received. The application is not designed to jump from one position to another in the program except as the program progresses in a normal play mode. If a special play mode is initiated while such an application is executing, the application can simply be terminated and restarted at the new position in the program. The application may be allowed to save information (e.g., state information) to persistent storage such as the storage device when it is terminated. It should be noted that the application may be removed from memory when it is terminated, so it may have to be downloaded again from the data stream and restarted after the program has jumped to the new position. Because these two types of applications are handled differently when special play modes are mitiated, it is contemplated that the applications will be configured to indicate to the receiver whether they are capable of handling special play modes. It is also contemplated that some applications may be configured to prevent certain special play modes. For example, an application may be configured to prevent the user from rewinding or may allow the user to rewind only to certain positions, such as the beginnings of chapters. While the present invention has been described with reference to particular embodiments, it will be understood that the embodiments are illustrative and that the invention scope is not limited to these embodiments. Many variations, modifications, additions and improvements to the embodiments described are possible. These variations, modifications, additions and improvements may fall within the scope of the invention as detailed withm the following claims.

Claims: VVHA I IS CLAIMED IS: 1 A method comprising receiving a broadcast signal, wherein said broadcast signal contains a program and wherein said program contains one or more interactive applications, storing said program on a storage device, initiating playback of said program from said storage device, and launching a first interactive application of said one or more interactive applications in response to detecting said first interactive application during said playback of said program 2 The method of claim 1 wherein said program is stored on said storage device as it is received, wherem detecting said first interactive application compπses detectmg said first interactive application is available from an mteractive application data stream of said program durmg said playback 3 The method of claim 1 wherem storing said program mcludes stormg an mteractive application data stream of said program, wherem said stormg of said data stream compπses extracting from said program one or more data objects and stormg said data objects on said storage device as a set of files, wherem mitiatmg playback of said data stream compπses retnevmg one or more of said set of files from said storage device and wherem detectmg said one of said one or more mteractive applications compπses comparmg a validity range associated with said one of said one or more applications to a current playback mdex and determmmg that said current playback mdex is within said validity range. 4. A method compπsmg: providmg a program stored on a storage device, wherem said program contams an mteractive application; mitiatmg playback of said program from said storage device, launching said mteractive application; mitiatmg a special play mode of said program; and conveying a notification signal to said mteractive application durmg said special play mode. 5 The method of claim 4 further compπsmg mitiatmg a special play mode of said program wherein durmg said special play mode, a current playback mdex changes from a first value to a second value, determmmg whether events affecting the state of said interactive application would have been encountered in a normal play mode between said first value and said second value, generating signals corresponding to said events; and conveying said signals to said application 6 The method of claim 5 wherem said signals are generated sequentially according to the order of said correspondmg events m a normal play mode 7 The method of claim 4 wherein one or more of said notification signals are selected from the group consisting of application kill signals, application launch signals, application pause signals, application resume signals, trick mode start notifications, trick mode end notifications, seek notifications, module notifications, trigger notifications, and accelerated version notifications 8 The method of claim 4 further comprising said interactive application receiving an indication of a current position in said program and setting the internal state of said interactive application to correspond to said current position 9 The method of claim 8 wherem said application receives said indication of said current position m said program while said program is m said special play mode 10 The method of claim 4 further compπsmg mitiatmg a special play mode of said program, conveymg a kill signal to said mteractive application m said program, terminating said special play mode; and launching an mteractive application m response to detectmg said mteractive application is available 11. The method of claim 4 further compπsmg said mteractive application. indicating to a receiver on which said mteractive application is executmg whether said mteractive application is configured to operate when a special play mode is mitiated, notifying said mteractive application of said special play mode m response to detectmg said mteractive application is configured to operate duπng said special play mode, and terminating said mteractive application when said special play mode is used m response to detectmg said mteractive application is not configured to operate duπng said special play mode. 12 The method of claim 4 further compπsmg: broadcasting said program; receiving said program; and stormg said program on said storage device 13. A device compπsmg a receiver; and a storage device coupled to said receiver, wherem said storage device is configured to store a program data stream mcludmg one or more mteractive application data streams and to provide said program data stream to said receiver for playback, and wherem said receiver is configured to detect and launch said one or more interactive applications 14 I lie device of claim 1 wherein said leceiver is conf igured to be coupled to an interactive television system wherein said receiver is configured to receive said program data from said interactive television system, and wherein said receiver is configured to store said program data in said storage device 15 ITie device of claim 11 wherein said storage device is configured to store said program data stream as it is received wherein said receiver is configured to receive said data stream and to determine when said one or more interactive applications are available in said data stream, and wherein said receiver is configured to launch said one or more interactive applications, in response to detectmg said one or more interactive applications are available 16 The device of claim 13 wherein said storage device is configured to store said program data stream as a set of files, wherein said receiver is configured to retrieve one of said set of files containing interactive applications, wherein said receiver is configured to compare validity ranges associated with said mteractive applications to a current playback index, and wherein said receiver is configured to launch ones of said interactive applications for which said associated validity range mcludes said current playback index 17 The device of claim 13 wherem said receiver is configured to play back said program usmg a special playback mode between a first playback mdex and a second playback mdex, wherem said receiver is configured to determine whether one or more events affectmg the state of said program would be encountered m a normal playback mode between said first playback mdex and said second playback mdex, wherem if said one or more events would be encountered m said normal playback mode, said receiver is configured to generate one or more signals indicative of said one or more events and to provide said one or more signals to said program 18 The device of claim 13 wherem said receiver is configured to receive a notification from a first mteractive application of said one or more interactive applications mdicatmg whether said first mteractive application is configured to operate m special playback modes, wherem if said first mteractive application is configured to operate in special playback modes, said receiver is configured to provide a notification of said special playback mode to said first mteractive application when said special playback mode is used, and wherem if said first mteractive application is not configured to operate m special playback modes, said receiver is configured to terminate said first mteractive application when said special playback mode is used 19 The device of claim 18 wherein when use of said special playback mode is stopped, said receiver is configured to restart said first mteractive application 20 The device of claim 19 wherem said receiver is configured to restart said first interactive application by extracting said first mteractive application from a data stream 21 The device of claim 13 wherem said receiver is configured to receive an indication from one of said one or more applications which indicates that a special playback mode can be used by said receiver

Inventors: DELPUCH ALAIN, DUREAU VINCENT, PIERRE LUDOVIC, DELPUCH, ALAIN, DUREAU, VINCENT, PIERRE, LUDOVIC
Applicants: OPENTV CORP, OPENTV, CORP.
Application year: 2000
Main classification: H04N5
IPC codes: H04N5, H04N7