KR20000022385A - Video delivery system and method which displays a slider bar on the subscriber video screen for indexing into a video stream - Google Patents

Abstract

PURPOSE: A system is provided to display A system and method which displays a graphical icon, such as a slider bar,on a subscriber's television or display unit for indexing to different positions in a video stream in an interactive video delivery system. CONSTITUTION: The interactive video delivery system preferably comprises at least one media server which stores one or more video streams, and one or more subscribers which each include a display device, such as a television. The television displays a slider bar or other graphical icon, and the slider bar is used to index to different locations in the video stream. During video delivery, the user may use or adjust a knob on the slider bar, preferably using a remote control device, to indicate a desire to "jump" to a different location in the movie or video stream. The media server receives the slider bar user input from the subscriber device and begins outputting the normal play stream at the desired position.

Description

Video delivery system and method for displaying slider bars on subscriber video screens for indexing into video streams

On-demand or video delivery systems allow multiple subscribers or users to select and watch a movie or other audio / video sequence stored on one or more video servers or media servers. The video server is connected to multiple subscribers or users through data transmission channels such as broadcast cable systems or satellite broadcast systems. The video server stores multiple movies or other audio / video sequences, and the user can select one or more movies from the video server to watch. Each user includes a television or other viewing device, and associated decoding logic, for selecting and watching a movie to watch. When the user selects a movie, the selected movie is sent to each user's television through one of the data transmission channels.

Full video digital video requires a large amount of storage and data transmission bandwidth. Thus, on-demand systems use several types of video compression algorithms to reduce the storage and data transfer bandwidth required. In general, different video compression methods exist for still graphic images and moving images. A video compression method for a still graphic image or a single video frame is called an intraframe compression method, and a compression method for moving picture video is called an interframe compression method.

Examples of video data compression for still graphic images include RLE (run-length encoding) and JPEG (Joint Photographic Experts Group) compression. The RLE compression method checks for pixels overlapping in one line of a bitmap, and compresses by storing the number of consecutively overlapped pixels instead of the data for the pixels themselves. JPEG compression is a related set of standards that provides either lossless (no degradation in quality) or reduced (no significant degradation) compression. JPEG compression was originally designed for the compression of still images, not video, but JPEG compression is used in some moving image applications.

In contrast to the compression algorithm for still images, most video compression algorithms are designed to compress fully moving picture video. Video compression algorithms for moving picture video use a concept called interframe compression, which involves storing only differences between successive frames in a data file. Interframe compression generally stores the entire key frame or reference frame image in a moderately compressed format. Subsequent frames are compared with the key frame, and only the difference between the key frame and the subsequent frame is stored. Periodically, for example, when a new scene is displayed, a new key frame is stored, and the comparison starts from this new reference point. Note that the interframe compression ratio remains constant even when the video quality changes. Alternatively, the interframe compression ratio may depend on the content, i.e. compression is less effective if the video clip being compressed contains a lot of sudden scene changes between images. Examples of video compression using interframe compression techniques include MPEG, DVI and Indeo.

MPEG background

A compression standard called MPEG (Moving Picture Experts Group) compression is a method of compressing and decompressing a complete moving picture video image using the above-described interframe compression technology. MPEG compression uses moving picture compression and discrete cosine transform (DCT) processing and provides compression ratios of 200: 1 or more.

In the MPEG standard, sound must be recorded simultaneously with video data, and the video and audio are interleaved into a single file to keep the video and audio in sync during playback. Typically audio data is also compressed, and the MPEG standard specifies an audio compression method, such as MPEG Layer II, also known as the Philips trade name "MUSICAM."

The MPEG stream includes three types of pictures, namely intra (I) frames, prediction (P) frames, and bidirectional interpolation (B) frames. I or intra frames contain video data for the entire frame of video and are typically placed every 10 to 15 frames. Intra frames provide a file entry point for random access and are generally only compressed appropriately. The predictive frame is encoded with respect to a past frame, i.e., a previous intra frame or a predictive frame. Thus, P frames contain only changes relative to the previous I or P frame. In general, the predictive frame is compressed to a considerably high amount and is used as a reference for the next predictive frame. Thus, I and P frames are used as a reference for subsequent frames. Bidirectional pictures contain the largest amount of compression and require past and future criteria to be encoded. The bidirectional frame is not used as a reference for other frames.

After the I frames are generated, the MPEG encoder divides each I frame into 16 x 16 pixel grid regions called macro blocks. Each picture following the I frame is also divided into the same macro blocks as described above. The encoder then searches for an exact or near exact match between the reference picture macroblock and the macroblock of the next picture. If a match is found, the encoder delivers a vector motion code or motion vector. The vector motion code or motion vector only contains information about the difference between the reference frame and each successive picture. Blocks of subsequent pictures that do not change at all relative to the block of the reference picture or frame are ignored. In general, for frame (s) following a reference frame, i.e., P and B frames following a reference I or P frame, only a small portion of these frames is different from the corresponding portion of each reference frame. Thus, for these frames only the difference is taken and compressed and stored. Thus, the amount of data actually stored for these frames is significantly reduced.

After the motion vector is generated, the encoder uses spatial redundancy to track the change. Accordingly, after finding the position change of the macro block, the MPEG algorithm further reduces the data by describing the difference between the corresponding macro blocks. This is accomplished through a mathematical process called discrete cosine transform, or DCT. This process divides the macro block into four sub-blocks and finds the color and brightness changes. Human perception is more sensitive to brightness than changes in color. Therefore, the MPEG algorithm reduces the color space more than the brightness.

Each picture or frame includes a picture header that identifies the frame and includes information about the frame. The MPEG standard includes a sequence header that identifies the start of a video sequence. The sequence header is only needed once before the video sequence begins. However, the MPEG-2 standard allows a sequence header to be sent before any I or P frame. The sequence header contains information related to the video sequence, including frame rate and picture size, among other information.

MPEG video streams used in digital television applications include a sequence header before every I frame and P frame. This is necessary to allow easy channel navigation between different video channels, which is an important user requirement. In general, when a user switches to a new channel, the video of the new channel cannot be displayed until the next sequence header appears in the stream. This is because the sequence header contains important information about the video sequence that the decoder needs before the sequence can be displayed. If a sequence header is not included before each I frame and / or P frame, when the user switches to the new channel, the video of the new channel may not be displayed immediately. That is, the video cannot be displayed until the next sequence head.

The sequence header in the MPEG encoded stream includes a time stamp indication used to provide a time stamp or time base in the encoded stream.

Trick play stream

In an interactive on demand (VOD) or similar on demand (NVOD) system, it is desirable to be able to selectively move the movie being watched by the user at a high speed and / or back at a high speed. Thus, some on-demand systems include fast forward and fast reverse streams for each movie, which are called trick play streams. Each fast forward or fast reverse trick play stream is sent to the user at the appropriate point that the viewer was watching, instead of the normal play stream, resulting in fast forward or fast reverse of the movie being watched. As a result, a single video stream such as a movie is encoded at different display speeds so that the video file can operate at high forward or backward speeds in addition to the normal playback speed.

index

Interactive on-demand systems that include trick play streams require an index between normal and trick play streams, and a method of indexing between trick play streams. That is, when the user is watching a movie and selects fast forward for a period of time, a mechanism is needed to cause the video server to switch from the normal playback stream to the appropriate point or frame in the fast forward stream. When the user wants to resume watching at the normal playback speed, there is also a need for a mechanism that allows the video server to switch from a frame viewed at fast forward to a suitable point or frame in the normal playback stream. Accordingly, the video server should be able to determine a suitable location within the video file when a transition occurs that outputs from the first video file at the first display rate to the second video file at the second display rate.

Other types of indexing systems and methods are desirable to allow users to easily navigate to different locations in the movie. For example, it would be highly desirable to be able to selectively jump immediately to any location within the video stream without having to watch trick playback fast forward or fast backward during processing. Therefore, an improved indexing system and method for efficiently indexing to different locations within a video stream in a video delivery system is desirable. It would also be desirable to have an improved indexing system and method that allows a user to selectively jump instantly to any point in the video stream. Improved indexing systems and methods that do not require trick playback systems and reduce the processing burden of the media server are also desirable.

The present invention relates to video delivery and video-on-demand systems, and more particularly to a video delivery system and method for displaying a slider bar on a subscriber television or display device for indexing to a location in a video stream.

1 illustrates a video delivery system including one or more media servers and one or more subscribers.

2 shows a user watching television displaying a slider bar for indexing into a video stream according to the invention.

3 shows the media server of FIG.

4 is a block diagram illustrating the media server computer system of FIG.

5 is a flow chart illustrating the generation of an index lookup table for a normal play stream and a trick play stream in accordance with the present invention.

6 illustrates an index lookup table for a normal playback stream and a trick playback stream in accordance with the present invention.

FIG. 7 is a flow diagram illustrating the operation of a set top box that receives user input regarding user operation of a slider bar and provides related information to a media server.

8 is a flow diagram illustrating the operation of a media server indexing a new location in a normal playback system based on user input received from a set top box in accordance with the present invention.

The present invention includes systems and methods for displaying graphical icons such as slider bars on a subscriber's television or display device for indexing to different locations within a video stream in an interactive video delivery system. The interactive video delivery system preferably includes at least one media server storing one or more video streams, and one or more subscriber devices each including a display device such as a television.

In a preferred embodiment, the media server stores normal playback streams and may store one or more corresponding trick playback streams, i.e., fast forward and / or fast backward video streams, for each normal playback stream. In a preferred embodiment, the media server stores the normal playback video stream, preferably compressed using various types of video compression methods, preferably the MPEG method. The system of the present invention creates an index table or lookup table for each normal playback stream that enables indexing to different locations in the stream. When generating the index table for the normal play stream, the system first analyzes the normal play stream to generate a normal play time reference based on the display time stamp preferably included in the normal play stream. The system then preferably creates an index table or lookup table for the normal playback stream using the normal playback time criteria. Each index table contains two groups of arrays, two groups of which are the normal playback time criteria and the index or offset to each stream. The index table allows indexing to different locations in the stream. If the media server is storing trick play streams, the system also preferably creates an index table for trick play streams that allows indexing between normal play streams and trick play streams.

Interactive applications operating on set top boxes coupled to televisions display graphical icons such as slider bars on the television screen. In an alternate embodiment, the media server provides graphical data displaying a slider bar on the screen. In a preferred embodiment, the slider bar is displayed when the user pauses the movie. When the slider bar is displayed, the user may use or adjust the knobs of the slider bar to direct the bar to "jump" to different locations in the movie or video stream, preferably using a remote control.

In a preferred embodiment, the subscriber device or set-top box receives user input and calculates a value in the range of 0 to 100 indicating the relative position in the movie or stream based on the user manipulation of the slider bar. The set-top box then provides this value to the media server. The media server receives a value representing the slider bar user input from the subscriber device and calculates a normal play time value based on the received user input. The media server receives a value in the range of 0 to 100 and uses the movie length to calculate the corresponding normal play time value. For example, if the user adjusts the slider bar so that the "knob" of the slider bar lies exactly in the middle of the slider bar, the subscriber device provides 50 outputs to the media server. If the movie length is exactly two hours, the media server outputs one hour of normal playback time.

The media server then uses each index table to index the normal playback video stream. After the media server calculates the new normal play time, the media server uses the calculated normal play time to retrieve the appropriate offset in the normal play stream index table. This offset is used to start playback of the normal playback stream at the loaded offset. The set-top box adjusts the position of the knobs on the slider bar to reflect the exact position of the output video stream. The media server also optionally checks the current normal playback time and the offset of the output normal playback stream to stop the normal playback stream at the appropriate point before outputting the stream at the imported offset.

In one embodiment, when the user first manipulates the slider bar to jump to a new position in the video stream, the media server temporarily caches the current normal play time and the byte offset of the normal play stream. Thus, if the user later wants to return to the original position in the movie before any slide bar adjustment has been made, the user presses a key on the remote control or selects the return option of the slider bar. This selection causes the media server to retrieve the appropriate normal play time and offset within the normal play stream index table. This offset is then used to play the normal playback stream at the position where the stream was originally before any slider bar adjustments.

Therefore, the present invention makes it possible to efficiently index to different positions in the normal playback stream. The present invention displays graphical icons such as slider bars that provide a simple and convenient mechanism for selecting a location within a video stream. The present invention creates a normal playback time criterion used as a common criterion, thus simplifying the indexing process.

The invention can be better understood when considering the following detailed description of the preferred embodiment in conjunction with the accompanying drawings.

Video delivery system

1 illustrates a video server or video delivery system 30 for storing and transmitting video streams. The system 30 is preferably a video on demand (VOD) or similar on demand (NVOD) system, or other form of video delivery system, capable of transmitting or playing video or multimedia streams to one or more users, preferably multiple users. Do. As used herein, the term "video stream" is used to refer to a file or sequence that represents a video display. The term "video stream" also encompasses a multimedia stream that includes both video and audio components.

As shown, in one embodiment video delivery system 30 includes one or more media servers or video servers 50 connected to a plurality of subscribers 52 over broadband network 40. As discussed below, each media server 50 preferably includes a general purpose computer system 60 (FIG. 2). The broadband network 40 is preferably a network suitable for multimedia contents such as ATM (asynchronous transmission mode) network, satellite broadcasting network, or IP / RTP (Internet Protocol / Real Time Protocol) network. Subscriber 52 preferably includes a display device such as a television, a computer, or the like. The media server 50 provides a video or multimedia stream to each subscriber 52 via the broadband network 40.

The media server 50 may transmit or play a plurality of video or multimedia streams. In the preferred embodiment, the system 50 may transmit or play the normal playback stream at any of several designated locations. As used herein, the term "normal playback stream" refers to a video stream designated for playback at normal or standard display speed. In one embodiment, each normal play stream may also have one or more trick play streams involved that may include one or more fast forward and / or fast backward streams. As used herein, the term " trick playback stream " refers to a fast forward and / or fast backward video stream, preferably compressed streams, which are reproduced from the normal playback stream and have a different display speed than the information playback stream. .

The normal playback stream is preferably a compressed video stream. The invention works regardless of the form or format of the video stream. Therefore, the normal playback stream includes MPEG-1, MPEG-2, moving picture JPEG, QuickTime, and the like, and can be compressed in any of various forms. Moreover, the present invention operates independently of the frame rate and other display characteristics.

Figure 2-Subscriber Device

2 shows a user viewing subscriber device 52 in accordance with a preferred embodiment of the present invention. As shown, subscriber device 52 includes a television or other display device 53. Television 53 includes a display screen 59 for displaying video images, as is well known in the art. The television or display device 53 may include any of various types of display devices, including digital TVs or high-definition televisions (HDTVs), computer systems with video monitors, or other types of display devices.

The subscriber device 52 also includes a set top box 57 or other logic coupled to the television 53. The set top box 57 is coupled to the network 40 and connected to a cable 58 coupled to the media server 50. Set top box logic 57 may be included within television 53 or may include an adapter card inserted into a bus of a computer system. The term "set-top box" refers herein to any form of external logic or server, or any form of logic contained within a television or other display device, and refers to the display of multimedia content, such as video or audio decompression. To perform related processing functions, to execute interactive applications or to display the slider bar 54 of the present invention.

As shown, the display screen 59 of the television 53 displays a graphic icon 54 so that the user can index to the desired location of the video stream. In a preferred embodiment, graphic icon 54 is slider bar 54. Slider bar 54 includes a small knob or cursor 55 that can be moved within slider bar 55. As used herein, the term "slider bar" includes both slider bar 54 and knob 55. The term "slider bar" as used herein is intended to include other graphical icons for indicating locations within the video stream. As shown, a user using the remote controller 56 preferably operates a button or dial on the remote controller 56 to control the movement of the knob 55 in the slider bar 54. The user can manipulate or adjust knob 55 in slider bar 54 to "jump" to a position in the desired movie or video stream to be watched. Thus, if the user starts watching the movie and wants to "fast forward" or "jump" to the end of the movie, the user simply uses the remote controller 56 to move the knob 55 in the slider bar 54 to the slider bar ( 54 from left to right, ie from the beginning of the movie to almost the end of the movie.

In response to user manipulation of knob 35 in slider bar 54, set top box 57 receives a signal. The set top box 57 calculates the information based on the received user input and provides the information back to each video server 50 providing a video output stream. As will be described further below, in response to user manipulation or adjustment of the slider bar 54, the video server 50 supplies the video output at a desired position in the video stream indicated by the manipulated slider bar 54.

In the preferred embodiment, the slider bar 54 is displayed by the set top box 57 connected to the television 53. In the preferred embodiment, the slider bar 54 is only displayed when the user stops the video stream. When the slider bar 54 is displayed, the set top box 57 updates the movement of the knob 55 in the slider bar 54 to reflect the current position of the video stream or movie being played on the television 53. Thus, when slider bar 54 is displayed on screen 58, knob 55 is displayed at a suitable location within slider bar 54 relative to the position of the video stream being displayed. In an alternative embodiment, the slider bar 54 is displayed continuously and the position of the slider bar knob 55 is updated when each video stream is provided to the television 53 via the set top box 57.

In an alternative embodiment of the invention, the slider bar graphic icon 54 is provided directly by the video server 50 with the output movie video stream. In this embodiment, the video server 50 only displays the slider bar 54 when a stop command is received or when another user input indicating that the slider bar 54 is to be used is received. Media server 50 displays knobs or cursors 55 at appropriate positions in slider bar 54 to reflect the current position of the movie being displayed.

Figure 3-Media Server

In FIG. 3, the media server or video server 50 in the preferred embodiment includes a computer system 60. Media server computer system 60 preferably includes various standard components, including one or more processors, one or more buses, hard drives, and memory. 4 is a block diagram illustrating components included in the media server computer system 60 of FIG. 4 is merely illustrative and may be used when other computer architectures are desired. As shown, computer system 60 includes at least one processor 80 coupled to system memory 84 via chipset logic 82. Chipset 82 preferably includes a PCI bridge for interfacing to PCI (Peripheral Component Interconnect) bus 86. Computer system 60 includes a RAID (redundant array of low cost disks) disk array 90 or other storage medium for storing normal playback streams and any corresponding trick playback streams. Computer system 60 may include either or both of MPEG decoder 74 and MPEG encoder 76, which are shown as being connected to PCI bus 86. Computer system 60 also includes video circuitry 88 as shown.

Again in FIG. 3, computer system 60 includes or is coupled to one or more digital storage devices or media storage devices. For example, in the embodiment of FIG. 2, computer system 60 couples to media storage 62 via cable 64. Media storage 62 may be present in addition to or instead of a disk storage system within computer system 60. Media storage 62 includes one or more composite RAID drives for storing normal playback streams and any corresponding trick playback streams. Alternatively, media storage 62 may instead comprise one or more CD-ROM drives and / or one or more digital video disc (DVD) storage, or other forms, for storing digital video or multimedia content. May include media. Computer system 60 may also include one or more internal CD-ROM drives or may be coupled to one or more separate digital video disc (DVD) storage. Computer system 60 may also connect to other forms of digital or analog storage, if desired.

Compressed normal play streams, and any related trick play streams, may be included in storage media in media server 50 such as, for example, CD-ROMs or digital video discs (DVDs). The media server 50 reads each normal play or trick play stream from the storage medium and provides the data to one or more display devices or viewers (subscribers) 52. The media server 50 may output video data using various communication media such as, for example, asynchronous transmission mode (ATM), integrated service digital network (ISDN), or via satellite. As noted above, subscriber display device 52 may include a computer television, computer system, or other system with a display screen for displaying video content.

As mentioned above, media server 50 generally indexes different locations within the normal playback video stream based on user selection. As will be described further below, media server 50 uses these tables to generate index tables for various normal playback streams and index them at different locations within the various streams. In the preferred embodiment, the function of creating and indexing the index table is performed by the media server 50 in software, where the software is provided by the floppy disk 72. In an alternate embodiment, computer system 60 includes dedicated hardware to perform one or both of the index table creation and indexing functions. In a third embodiment, a set of related streams, i.e., normal play streams and associated trick play streams, contain index information embedded in them to provide indexes between the streams.

Note that media server 50 may include two or more interconnected computers, if desired. Note that any one of various types of video delivery systems may be used in accordance with the present invention if desired.

Figure 5-Create Index Lookup Table

5 is a diagram illustrating generation of an index lookup table according to the present invention. It is assumed here that the normal playback stream is stored in the system. If one or more trick play streams are stored in the system, it is desirable that the different streams encode the same content for display at different rates. The method of Figure 5 is used to generate an index table for a normal playback stream so that it can index to different locations in the stream in accordance with the present invention. The method of FIG. 5 may also be used to generate an index table for indexing between normal playback video tricks and trick playback video streams, if desired.

As shown, in step 102 the system of the present invention receives or examines a normal playback video system or multimedia stream. As discussed above, a normal playback stream includes a video data stream that is used to represent a video sequence, such as a television fragment or movie, on a screen, such as a television or computer system. In a preferred embodiment, the normal playback stream is a compressed stream, preferably an MPEG-2 compressed stream, and other forms of compression may be used if desired.

In step 104 the system of the present invention preferably analyzes the time stamp in the stream. In the preferred embodiment where the stream is an MPEG stream, the system parses the display time stamp from the sequence header in the stream. As mentioned, the display time stamp is used to provide a time base for the video sequence.

As discussed above, an MPEG encoded stream includes a plurality of I-frames that are intracoded pictures, and a plurality of B and P frames that are intercoded frames. I frames each contain video data for the entire frame of video and are periodically placed in a sequence. P and B frames contain change information for the previous or subsequent frames. Each picture or frame includes a picture header that identifies the frame and includes information about that frame. The MPEG encoded stream further includes one or more sequence headers containing some information about the video sequence, including frame rate and picture size, among other information. The sequence header includes a display time stamp indicating the playback time of the video sequence.

In step 106, the system maps the display time stamp to the "normal playback time" standard. Thus, the system of the present invention defines a multimedia index based on the concept of "normal play time" which may be related to "position" in a multimedia title. Normal playback time standards are used to index different locations within the normal playback stream in accordance with the present invention. The normal play time standard may be used to index between streams having different display speeds, that is, between normal play and trick play streams. With respect to the trick play stream, the position at the time when the contents at each position are conceptually substantially identical, i.e. when the same or substantially the same image in the sequence is being provided, taking into account the difference in resolution and other encoding parameters specific to the stream Is equally defined between the normal playback video stream and / or the trick playback video streams having different display speeds.

When generating a normal play time reference, the system of the present invention examines the display time stamp to keep track of the original or base display time stamp at the start of the movie. The system then subtracts the base or original presentation time stamp from the subsequent time stamp to determine the normal playback time value for the normal playback stream. That is, to calculate the normal playback time for a given point in the normal playback stream, the system determines the base display time from the future mark time stamp at each point or location in the normal playback stream to determine the normal playback time for that location. Reduce the stamp.

In a preferred embodiment, the normal playback time (NPT) for a location in the multimedia stream is the time from the start of the title to each location as measured by normal speed forward or by indication of the normal playback stream, one to one with clock time. It has a correspondence relationship. Thus, every second the normal playback movie is advanced and the normal playback time is one second. In a fast forward title or fast forward trick playback stream, if the FF stream is five times faster, the normal playback time is five times faster when the user is watching. In general, any particular scene in a movie is identified by normal play time. Thus, if a particular scene occurs at X minutes in the movie at normal playback time, this position or scene is referred to as X minutes. This particular scene is also located in either of the other trick play streams at X minutes of normal play time.

Note that other methods may be used to generate index tables for normal play streams and trick play streams. In an alternative embodiment, the system of the present invention creates an index lookup table using an offset list for each GOP (picture group). In another embodiment, the system uses the presentation time stamp in the video stream to index. Other methods of creating index tables may be used if desired. Note that other methods may be used to create a normal playback time (NPT) reference index table for a normal playback system.

In step 108 the system creates an index lookup table for each multimedia normal playback stream. The index lookup table for normal playback multimedia streams includes two groups of indexes or arrays, each group containing a normal playback time and an offset in each stream. If a trick play stream is present in the system at step 110, the system optionally generates an index lookup table for the trick play stream. An index lookup table for normal playback, fast forward, and fast reverse streams is shown in FIG. 6. As shown, each group includes a normal playback time value and a corresponding file offset in the stream. For a normal play stream, the normal play time entry includes the normal play time value calculated in step 106. For trick playback systems with constant bit rate encoding, a proportional ratio is introduced to the normal playback time value of the index lookup table to compensate for different display speeds.

The index lookup table specifies an index or entry based on the normal playback time and file offset, respectively, so that the multimedia server 50 can start or stop playback at a particular normal playback time point in the multimedia stream. The index lookup table for the normal playback stream is used in accordance with the present invention such that the media server 50 outputs video data for the normal playback video stream at various locations indicated by the user input to the slider bar 54. do. The index lookup table for the trick play stream allows the multimedia server 50 to transmit to and from the same location of the stream having different display rates, i.e., between the normal play stream and the trick play stream.

In one embodiment, the index lookup table contains only a group that indicates a valid location for starting, stopping, or inter-stream transmission of the stream. Note that although the actual display speed from the beginning of the stream to its location will vary for different streams, equivalent positions in multimedia streams with different display speeds will have the same NPT value. Note that even if they have the same NPT value, equivalent positions in multimedia streams having different display rates will have different byte offsets due to the length difference of estimated streams having different display rates.

The creation of lookup tables is independent of any particular type of video compression or MPEG representation. In a preferred embodiment where MPEG compression is used, an index lookup table is generated by examining the entire MPEG file, taking a random access point in the MPEG file, and converting from the display time stamp in the MPEG file to the normal playback time reference. Conceptually, each index table contains an array of normal playback times for the scene, and any particular image or frame in the movie can be identified by the normal playback time value. As mentioned above, an index table is created for normal playback streams and certain trick playback streams, for example fast forward and fast reverse streams. Each offset stored in the index table is an index from the normal playback time to the byte offset in the MPEG file at which a particular scene begins.

Therefore, in a preferred embodiment, the system of the present invention uses normal playback time criteria for the index table. In an alternative embodiment, the system of the present invention creates an index lookup table using an offset list for each GOP (picture group). As mentioned above, you can use other methods of creating index tables if you wish.

Figure 7-Set Top Box Operation

7 is a flowchart illustrating the operation of the set top box 57. 7 illustrates the operation of the set top box 57 with respect to the operation of the slider bar 54 and the user operation of the knob 55 on the slider bar 54. As shown, in step 160 set-top box 57 displays slider bar 54 and knob 55 on the television screen, as shown in FIG. In the preferred embodiment, the user presses the pause button on the remote controller 56 such that the slider bar 54 is displayed. That is, the slider bar 54 is displayed when the user presses the pause button. In another embodiment, the user's remote control 56 includes a dedicated button or menu selection that causes the slider bar 54 to be displayed or not. Thus, in the flow chart of FIG. 7, it is assumed that set top box 57 displays slider bar 54 in response to user input from remote controller 56.

In step 162, the set top box 57 updates the position of the slider bar knob 55 in the slider bar 54 based on the position of the video stream received from the media server 50. Thus, when the slider bar 54 is displayed, the set top box 57 updates the position of the slider bar knob 55 to the position where the video stream or movie is being played. Thus, slider bar knob 55 displays the relative portion of the displayed movie. Note that step 162 is an optional step that can be omitted, that is, the slider bar knob 55 may be updated based on the user's operation of the slider bar 54 and not based on normal playback of the movie or video stream.

When the user enters the slider bar knob 55 as determined in step 164, in step 165 the set top box 57 calculates a relative value within the selected range based on the new position of the knob 55. Thus, it is assumed here that a user using the remote controller 56 or other device has manipulated the slider bar knob 55 of the slider bar 54 to jump or index to different places in the video stream or movie. When it is determined in step 164 that a user input has been received, the set top box 57 calculates a value within a predetermined range. In a preferred embodiment, the predetermined range is a value between 0 and 100, where 0 is the absolute start of the movie or stream, 100 is the absolute end of the movie or stream, and values between them represent relative positions within the stream. Thus, after the user operates the slider bar knob 55, the set top box 57 examines the new position of the knob 55. That is, the received user input is analyzed to calculate a relative value between 0 and 100 based on the new position of knob 55 in step 166. After calculating this new relative value in step 166, the set top box 57 provides the calculated value to the media server 50 in step 168. As will be explained further below, this calculated value is received by the media server 50 and used to input the video stream at a new location based on the user manipulation of the slider bar knob 55.

Figure 8-Media Server Operations

8 is a flowchart for explaining the operation of the media server 50 for transmitting the normal playback video stream in response to the user operation of the slider bar 54. As shown in FIG. Here, the video stream or the multimedia stream is output from the media server 50 to the subscriber device 52, and the user can use the knobs of the slider bar 54 to index or "jump" to different parts or places in the stream or movie. Suppose you have adjusted

In step 202, media server 50 receives information from set top box 57 generated in response to user input from slider bar 54. User input is initially provided by the user to the television and / or set top box 57, which is provided to the media server from the set top box 57 in step 202. In a preferred embodiment, the user input received in step 202 is provided by subscriber device or set-top box 57 and is preferably 0-100, indicating a relative position in the movie based on user manipulation of slider bar 54. Contains a value within the range.

In step 204 the media server 50 determines a new normal play time value based on the received user input. In step 204, the media server 50 calculates a normal play time value using a value within a predetermined range, that is, a value within 0-100, and also using a movie time length stored in the memory of the media server 50. . For example, if the user adjusts the knob of the slider bar so that the knob is positioned exactly in the middle of the slider bar 54, the set top box 57 provides 50 output to the media server 50. If the movie length is exactly 2 hours, the media server 50 outputs the normal playback time value of one hour. The normal reproduction time value is calculated as 0.5 x 2 hours = 1 hour. In another example, if the user adjusts the slider bar 54 such that the knob 55 is positioned exactly one third of the position in the slider bar 54, i. Gives 33 outputs. If the movie length is exactly two hours, the media server 50 outputs a normal playback time value of 40 minutes, which is 1/3 of the movie length.

In a preferred embodiment, a program running on the media server adjusts the movie time length by parameters 0-100 received from the set-top box and places the movie or video sequence at the resulting normal play time (NPT) value. Ask. Note that other methods may be used to determine the correct normal playback time based on the user input received at step 204. For example, in one embodiment, set top box 57 performs step 204. In this embodiment, the set top box 57 receives or takes the movie length value at the beginning of the movie or video stream and stores this movie length value in memory. Thus, when the set top box 57 receives a user input of placing a knob in the slider bar 54, the set top box 57 calculates the normal play time to be provided to the media server at step 202 using the movie length. . In this embodiment, the set top box 57 must access the index table, which is stored in the media server 50 or set top box 57.

After the new normal playback time is determined based on the user input received in step 204, the media server 50 indexes the new location in the normal playback stream based on the normal playback time determined in step 204. Accordingly, in step 206 the media server retrieves an offset from the normal play stream index table using the normal play time calculated in step 204. In step 208 the media server 50 outputs the normal playback stream at the indexed position or at the offset position determined in step 206.

Therefore, in response to the user operating the knob of the slider bar 54, the media server 50 selects each video stream at a new position in the stream based on the user operation of the knob 55 in the slider bar 54. FIG. Output This provides a very intuitive way for the user to fast forward and / or fast backward within the video stream. In other words, this provides a simple and intuitive mechanism that allows the user to jump to any desired place in the video stream.

Thus, the change in the position of the output of each stream output at a given normal reproduction time is achieved by using the associated file offset as the point of starting the stream reproduction by finding a group in each index table for the closest normal reproduction time.

In one embodiment of the present invention, the set top box 57 includes a cache memory for storing the position of the slider bar knob 55 prior to the user's manipulation of the slider bar knob 55. Thus, if a user watches a movie for 20 minutes, wants to move forward or backward to various different parts of the movie, and then wants to return to the original place of the movie to resume watching, the user may change the knob before any user manipulation of the slider bar. It is possible to select a button of the remote controller 56 to position the slider bar knob 55 to the position where it was.

Therefore, the present invention includes a system and method for providing graphical icons or slider bars for indexing to different locations within a normal playback video stream. The present invention examines the display time stamp in the sequence header of the normal playback stream to generate a normal playback time reference. The system then creates an index table or lookup table for the stream. The index table for the stream contains the normal playback time value and the corresponding offset into each stream. During playback, when the user manipulates or adjusts the slider bar knob, the subscriber device or set-top box uses its respective index table to intelligently jump or index to the appropriate location within the normal playback stream and output the stream at this new location. To start.

Although the system and method of the present invention has been described in accordance with the described embodiments, it is not intended to be limited to the specific form set forth herein, but alternatives, modifications, and equivalents may be suitably included within the spirit and scope of the invention as defined in the appended claims. It is to include.

Claims (33)

A computer-implemented method comprising a media server and a subscriber device coupled to the media server, wherein the subscriber device comprises a display screen for indexing to a location in a video stream in a video delivery system. Displaying the video stream received from the media server on the display screen of the subscriber device; Displaying a graphical icon on the display screen of the subscriber device and indexing a location within the video stream that can be adjusted to cause a change in the position of the received video stream; Receiving input from a user indicative of a desired change in output position of the video stream; Providing information to the media server by the subscriber device in response to receiving an input from the user; Determining, by the media server, a new output location for the video stream in response to receiving the information from the subscriber device; And In response to determining the new output location, the media server outputting the video stream at the new location. 2. The method of claim 1, wherein receiving the input comprises receiving adjustment of the graphical icon. 3. The graphical icon of claim 2, wherein the graphical icon includes an adjustable knob that can be adjusted to cause a change in position of the received video stream, and wherein receiving the input comprises moving the knob within the graphical icon to a new position of the graphical icon. Positioning method in a video stream comprising moving. 2. The media server of claim 1, wherein the media server stores an index table corresponding to the video stream, wherein the index table includes a plurality of groups, each group being a first value and an offset into the position of the video stream. A second offset value, wherein the media server determines a new location of the video stream in response to the received user input, wherein the media server indexes the index lookup table to obtain an offset into the video stream. And indexing the location within the video stream. 5. The apparatus of claim 4, wherein each of the plurality of groups comprises a normal play time value and an offset into the video stream; Providing the information by the subscriber device comprises providing the subscriber device with a value within a predetermined range indicating a relative position in the video stream based on the received user input; Determining, by the media server, a new output location for the video stream, the media server determining a normal playback time based on the received value within the predetermined range. 6. The method of claim 5 wherein the predetermined range is a value within 0-100. 2. The position in the video stream of claim 1, wherein the graphical icon includes a slider bar comprising a knob, the knob positioned at a position in the slider bar to indicate the position of the output video stream received by the subscriber device. Index method. 2. The method of claim 1, further comprising receiving user input to pause the video stream, Displaying the graphical icon on the display screen of the subscriber device is performed in response to receiving the user input to pause the video stream. 9. The method of claim 8, wherein the graphical icon includes an adjustable knob that can be adjusted to cause a change in position of the received video stream, the method comprising: Updating the position of the knob on the graphic icon in response to displaying the graphic icon on the display screen of the subscriber device, wherein the updating comprises: updating the graphic according to the current position of the output stream. A method of indexing locations in a video stream that updates the position of the knob on an icon. 2. The method of claim 1, wherein the subscriber device comprises a television. 2. The method of claim 1, wherein the subscriber device comprises a television and a set top box coupled to the television. An interactive video delivery system that enables a user to index a location within a video stream, Outputting a video stream, the media server being capable of selectively outputting the video stream at different locations of the video stream; And A combined subscriber device coupled to the media server to receive the video stream output from the media server, wherein the subscriber device comprises: A display screen that displays the video stream received from the media server and also displays a graphical icon for indexing to a location within the video stream that can be adjusted to cause a change in the position of the received video stream; An input for receiving an input from a user indicating a desired change in output position of the video stream; And Means for providing information to the media server in response to receiving input from the user, The media server includes an input for receiving the information; The media server outputs the video stream at a new location in response to receiving the information from the media server. 13. The interactive video delivery system of claim 12 wherein the subscriber device input comprises an input for receiving an adjustment to the graphical icon. 14. The apparatus of claim 13, wherein the graphical icon includes an adjustable knob that can be adjusted to cause a change in position of the received video stream, wherein the knob within the graphical icon can be moved to a new position within the graphical icon; The subscriber device input includes an input for receiving an adjustment to a knob in the graphical icon. 13. The interactive video delivery system of claim 12 wherein the media server includes means for determining a new output location for the video stream in response to receiving the information from the subscriber device. 16. The system of claim 15, wherein the media server includes a plurality of groups each including a first value and a second offset value that is an offset to a location of the video stream, wherein the media server stores an index table corresponding to the video stream. Further includes memory, And the means for determining a new output location for the video stream indexes the index lookup table stored in the memory to obtain an offset into the video stream. 17. The apparatus of claim 16, wherein each of the plurality of groups comprises a normal playback time value and an offset into the video stream, The information providing means provides a value within a predetermined range indicating a relative position in the video stream based on the received user input, And said means for determining a new output location for said video stream determines a normal playback time value based on said received value within said predetermined range. 18. The system of claim 17, wherein the predetermined range is a value in the range 0-100. 13. The interactive video delivery system of claim 12, wherein the graphical icon includes a slider bar comprising a knob, the knob positioned at the position in the slider bar to indicate the location of the output video stream received by the subscriber device. . 13. The method of claim 12, wherein the input for receiving an input from a user indicating a desired change in output position of the video stream operates in response to receipt of a user input to pause the video stream, And the subscriber device displays the graphical icon on the display screen in response to receiving user input to pause the video stream. 21. The apparatus of claim 20, wherein the graphical icon includes an adjustable knob that can be adjusted to cause a change in position of the received video stream. The subscriber device further comprises means for updating the position of the knob on the graphic icon in response to the subscriber device displaying the graphic icon on the display screen of the subscriber device, wherein the means for updating comprises: And update the position of the knob on the graphic icon according to the current position of the output stream. 13. The interactive video delivery system of claim 12 wherein the subscriber device comprises a television. 13. The interactive video delivery system of claim 12 wherein the subscriber device comprises a television and a set top box coupled to the television. A computer-implemented method of indexing a location of a video stream in a video display device comprising a display screen, the method comprising: Displaying the received video stream on the display screen of the video display device; Displaying a graphic icon on the display screen of the video display device, the graphic icon being indexable to cause a change in position of the received video stream; Receiving input from a user indicating a desired change in output position of the video stream; In response to receiving an input from the user, the video display device providing information regarding the desired change in the output position; And In response to receiving the information, the video display device receiving and displaying the video stream at a new location. 25. The method of claim 24, wherein receiving the input comprises receiving adjustments for the graphical icon. 26. The computer-readable medium of claim 25, wherein the graphical icon includes an adjustable knob that can be adjusted to cause a change in position of the received video stream, and wherein receiving the input comprises: placing the graphical icon within the graphical icon to a new location within the graphical icon. Moving a knob; location indexing method in a video stream. A video display device that enables a user to index to a location within a video stream, the video display device comprising: A video stream input configured to receive a video stream input from a media server; A display screen that displays the received video stream and also displays a graphical icon for indexing to a location within the video stream that can be adjusted to cause a change in the position of the received video stream; An input for receiving an input from a user indicating a desired change in output position of the video stream; And Means for providing information to the media server in response to receiving input from the user, And the video display device receives and displays the video stream at a new location in response to providing information to the media server. 28. The video display device of claim 27, wherein the input to receive an input from a user comprises an input to receive an adjustment to the graphical icon. 28. The apparatus of claim 27, wherein the graphical icon includes an adjustable knob that can be adjusted to cause a change in position of the received video stream, wherein the knob within the graphical icon can be moved to a new position of the graphical icon; And the input for receiving an input from the user comprises an input for receiving an adjustment for the node within the graphical icon. A computer-implemented method of indexing a location in a video stream in a video delivery system comprising a media server providing a video stream, the method comprising: Providing a video stream to a subscriber device; Receiving from the subscriber device an input containing information from the subscriber device relating to the change in position of the slider bar displayed on the subscriber device, the input indicating a desired change in the output position of the video stream; Determining, by the media server, a new output location for the video stream in response to receiving the information from the subscriber device; And In response to determining the new output location, the media server outputting the video stream at the new location. 31. The media server of claim 30, wherein the media server stores an index table corresponding to the video stream, the index table including a plurality of groups, each group being a first value and an offset into the position of the video stream. And a second offset value, wherein the media server determines a new output location of the video stream in response to the received user input, wherein the media server determines the index lookup table to obtain an offset into the video stream. Indexing a location within the video stream. An interactive video delivery system that enables a user to index a location within a video stream, A media server for outputting a video stream, the media server may selectively output the video stream at different locations of the video stream, the media server relating to a change in position of the slider bar displayed on the subscriber device. An input for receiving information from the subscriber device, wherein the media server outputs the video stream at a new location in response to receiving the information from the subscriber device. 33. The apparatus of claim 32, wherein the media server further comprises a memory for storing an index table corresponding to the video stream, the index table including a plurality of groups, each group of a first value and the video stream. A second offset value that is an offset into a position; The means for determining a new output location for the video stream indexes the index lookup table stored in the memory to obtain an offset into the video stream.