JP2004507939A - Method and system for actively modifying video content in response to processes and data embedded in a video stream - Google Patents

Abstract

Video or other media data is synchronized with a procedural data stream that modifies the video stream. When the video is played, reproduced, or rebroadcast, the video is modified according to the procedures specified in the procedural data stream. In an embodiment not described herein, the procedural stream contains commands that are executed as soon as they are received by the interpreter. In certain embodiments, the procedural data stream is incorporated directly into the media data stream and separated by a demultiplexer. In a more particular embodiment, the combined media / procedure data stream may be fragmented. Here, each subdivided part still carries an appropriate code for the part removed from the whole.

Description

[0001]
(Background of the Invention)
・ Technical field to which the invention belongs
The present invention relates to a video system in which video content is actively modified according to conditions such as a transmission site, user's preference, and more particularly, a procedure for controlling modification is embedded in the video stream. Or the video system synchronized with the video stream.
・ Background of the invention
Certain portions of the video content may be considered objectionable, while other portions may be considered harmless. This has reminded people to suggest incorporating markers into the video data that indicate parts that are considered undesirable for some viewers. An application functioning at the transmission location will recognize the marker in this video stream and selectively mute or erase the passband in response to the marker. For example, a PCT application published on May 22, 1998: WO 98/21891; "INHIBITION OF A TV PROGRAMME DISPLAY ACCODING TO THE CONTENTS" describes a portion of a video stream marked as containing an undesired theme. It discloses disabling.
[0002]
UK Application No. 2284914 filed Dec. 18, 1993; "DISCREATIONARY VIEWING CONTROL" restricts television programming based on date and time, program ID, program rating, etc. based on conditions defined at the transfer point Are disclosed. Again, the result is that the video signal is erased or suppressed when a particular condition exists.
[0003]
International application published on June 12, 1983: WO 83/02208; "METHOD AND APPARATUS FOR EDITION THE OUTPUT OF A TELEVISION SET" is an application for markers in video and applications that work on a television set-top box. A system for filtering content based on the content is disclosed. The markers inserted into this signal are graded according to the content. United Kingdom Application No. 2315175, filed Jul. 10, 1997; RESTRICTING ACCESS TO VIDEO MATERIAL, discloses a system in which video content is allowed to be transmitted or reproduced based on characteristics of the content. This filtering application is predefined in the context of transmission and recording or browsing.
[0004]
US Patent No. 5,751,335, filed February 23, 1996, entitled "VIEWING RESTRICTING METHOD AND VIEWING RESTRICTING APPARATUS" describes a system in which a television program is muted if it exceeds an authorized rating. Has been disclosed.
[0005]
U.S. Patent No. 5,778,135; "REAL_TIME EDIT CONTROL FOR VIDEO PROGRAM MATERIAL" discloses a system in which video is segmented and rated for each segment. The application deletes segments rated above the selected level. This is basically the same technology used in PCT application: WO 96/41438; "ENCODER APPARATUS AND DECODER APPARATUS FOR A TELEVISION SIGNAL".
[0006]
It is known to delete video content in response to a content indicator in a video stream. In a conventional system, the display of a video was prohibited at predetermined intervals, so that a part of the video was blocked. Further, the application that performs this blocking is predefined and executed in response to markers (ie, special code) in the video stream. Here, the term "code" in the present specification and the related art can refer to a marker or an indicator, but is distinguished based on context from the term "code" used to indicate a procedure or process. Please be careful. In addition, there is software, such as a computer game, that selectively plays a video sequence in response to an execution path based on user instructions. For example, multiple alternative video sequences may be created by a user that can be played during a game in response to a selection.
[0007]
There is a need for a mechanism that gives video content producers greater control over the features associated with the selective display of video content. Current technology limits such control to intermediate controls or the degree of sophistication provided at the transfer point.
[0008]
(Disclosure of the Invention)
Various techniques may be used to allow real-time modification of the video stream. According to the present invention, the manner in which this correction is made increases the range of possible corrections that may result. The method further increases the control that the producer of the video stream has over the functions provided at the receiving end. These benefits are provided by associating each video stream or file with one or more software procedures executed by a generator or display, such as a copy station (eg, storage station, transfer station, recording station, broadcast station, etc.). Is done. The generator receives both the raw video stream and code defining one or more procedures for performing, for example, modifying the video stream. For example, in one embodiment, the generator is a television. According to this embodiment, the television receives a video signal with an embedded procedure code. The television has an internal controller that separates software data from raw video data and executes software data that can modify the video data. For example, the software data may be included in a video blanking interval ("VBI") of the analog video signal, or may simply be included in a header file attached to the video file. In this embodiment, the internal controller may be programmed with an application programming interface ("API") that provides a set of functions that the procedure can access to create various effects. This can be a system like Java (R), or enhancements to Java (R). The software data is executed and defines the procedure for modifying the video data. The procedure is adapted to time or segment markers in the video data so that the procedure can identify the portion of the video data to be modified.
[0009]
This API may provide a dark function group or a light function group. This may be referred to as a high or low level. For example, the API may provide the ability to draw an object, such as a flat rectangle or stepped oval, of a specified color in a specified area of the display only at specific time intervals of the video. Such a feature may take its opinion from the procedure of specifying the coordinates, size and shape, color, and start and stop time segments of the object. Another example is to apply a specified filter to a portion of the screen. This filter mask may be provided as an opinion.
[0010]
By providing a number of functions or providing the basic functions that can be accessed and performed in a very wide variety of ways, the present invention provides a video content generator for distributing and using video content. To provide many functions and options. One consequence is that the available functions are not limited to a number of predefined functions in the transmission or output device (eg a television) as in the prior art. Many functional groups of more unified nature, and any of the basic functions, can provide the same degree of flexibility. Both may be provided.
[0011]
At the summary level, the present invention provides the ability to associate an executable procedure for modifying the video data with the video itself. This association processes the video substantially synchronized with the presentation of the video on a display processing device that ultimately converts the multiplexed or compressed coded signal into a video data stream. Can be provided by providing a procedure to do so. Packing the procedural code in the same or related file may provide the association. Other embodiments may make this association by providing interleaved embedded code in an analog or digital video data stream.
[0012]
Note that we use the terms "procedure", "code", and other words to refer to the definition of a process or potential process that broadly encompasses both declarative and procedural definitions. Therefore, we do not intend in any way to limit the algorithm by expressing the invention in such words. The present invention includes an event-driven language, an object-oriented language, and the like.
[0013]
Using the procedure defined for each video, it is clear that the range of possible modifications, conditions, rules, criteria, and possible options is too large to provide a comprehensive list. This is a great advantage. Furthermore, these possibilities need not be known when the display (recording, broadcast, etc.) device was developed. Thus, video content may be communicated with its own functional updates. Enhancements to the content are possible without requiring software changes on the display (or other) device. However, the number and types of modifications are endless. The following are some examples for illustrative purposes.
[0014]
Videos selected according to the user profile accessed by this procedure may be shipped with multiple language tracks.
[0015]
The procedure decrypts the video using the profile data and password entered by the user.
[0016]
The procedure applies a blur filter to a portion of a frame during a movie scene to hide the front nude.
[0017]
This procedure provides a control console that allows a user to speed up the display of video in response to the user's preferences entered on the console generated by the procedure.
[0018]
The procedure provides a low-resolution image and accepts data indicating a payment authorization to enable viewing the full-resolution video.
[0019]
The procedure recognizes portions of the video signal that contain material to be censored based on pattern recognition, greatly speeds up playback, and eliminates those portions by skipping frames.
[0020]
The procedure excludes sound track segments that exhibit spells, eg, indicated by markers in the video signal.
[0021]
Techniques that are not yet known, such as techniques that respond to the user profile in some special way or techniques that give the user specific choices, are transmitted with the video.
[0022]
This procedure provides text overlaid on the video. Alternatively, provide a Flash (R) animation over the video.
[0023]
The procedure retrieves commercials from a web site and occasionally displays the commercials in a video.
[0024]
The procedure further includes providing the user with a car that reduces the commercial by accepting payment for watching the video, as well as software that displays a banner ad until registered, thereby reducing the number and duration of commercials. To reduce.
[0025]
This procedure controls the reproduction rights such that the various license rights that can be exercised by the user are controlled by the profile file on the machine.
[0026]
A common feature of all the above examples is that the program associated with the file provides a pleasing feature without having to present the file on a display device or make it available on another reproduction device. It is. The present invention allows a creator or distributor of a video to control the display or other use of the video with great flexibility.
[0027]
In one embodiment, the procedure consists of commands operating on separate parts of the video stream. This execution environment is stateless so that any finite number of such parts are always copied using procedures applicable to them. Thus, information is not persisted over a separable portion of the media stream unless the attached procedure fails to generate the information itself if it was not found ("persisted" is referred to as "made to pesist"). Is a new word of meaning). To ensure that these separate parts are not divided by themselves, the environment used to make copies of parts of the program must respect the inseparability of the parts. One way to ensure that this atomicity is not violated is to block-encode each atomic portion so that the block cannot be read without all its bits. An example of an indivisible portion is a video segment in which a portion of a video image is filtered in a particular way, for example, to mask a portion of a nude scene. The procedure is performed to apply a mask and a number of frames, and may be performed to stop generating the mask. The part of the video between this start and stop command must not be split so that the start command is not activated prior to the sensitive theme.
[0028]
Another way to implement the invention is to include a unique state generation procedure code in every frame of the video. This environment is also stateless. Then, any number of frames that are copied will contain code suitable for applying the correct attributes to the frames. In the above example, if a filter is applied to a part of each frame of the sequence, the command to apply the filter and the definition of the filter come before each frame. In this embodiment, the environment is stateless between frames. This embodiment can also be used with a broadcast model. In addition to the procedure, information about the video may be encoded with the procedure data. For example, any copied video sequence may include extensive information about the video file from which the segment originated, as it may include titles, authors, descriptions, and the like. Such data need not be recorded for each frame, but may be distributed over a plurality of frames.
[0029]
BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding, the present invention will be described in connection with certain preferred embodiments with reference to the following exemplary drawings. With reference to the drawings, the details shown are by way of example, and are intended only to illustrate preferred embodiments of the present invention, and to provide the most beneficial and conceptual aspects of the present invention. It is emphasized that the description is presented to provide an easily understood explanation and what is believed to be. In this regard, no attempt has been made to show the structural details of the invention in more detail than necessary for a basic understanding of the invention. After reading the following description in conjunction with the drawings, it will be clear to a person skilled in the art how many aspects of the invention may be practically realized.
[0030]
(Detailed description of preferred embodiments)
Please refer to FIG. One example of a physical infrastructure capable of supporting the functional features of the present invention includes a viewing system 100 having a computer 140 and various types of input and / or recording devices. The latter includes a keyboard 112, a remote controller 110, a removable medium 120 such as a floppy disk (R), an optical disk, a memory card, a Philips Pronto (R), a programmable controller, a voice recognition / activation controller, a mouse, a gesture recognition controller, and the like. including. The data may be recorded on a local fixed disk drive 135. Output devices may include a monitor or television 130, speakers 131, and / or other output devices. Computer 140 (which may again be any computable device, as described in the section of the disclosure) receives data 160 and / or video 170 from an external source. This external source may be any data or signal source, such as broadcast transmissions, data records, the Internet, networks, satellite transmissions, circuit switched transmissions, and the like. Note that by the word "computer" we mean any digital device capable of performing the functional requirements described herein, such as a set-top box, embedded system, or recording device with a controller. Computer 140 executes the procedure. This procedure may be recorded on data record 135, embedded in data 160 and / or video 170 received from an external source, or embedded in a file transferred to the computer in the form of a data file. It may be. This procedure modifies the compressed or decompressed video. After modification, the video may be recorded on VTR 133, transmitted as a broadcast by wireless transmitter 137, or displayed on television or monitor 130. The inputs and outputs shown are exemplary only.
[0031]
In another embodiment of the present invention, data 160 and video 170 may be transmitted by two different transmitters. In yet another embodiment, the data 160 can be distributed by multiple transmitters, but the corresponding video 170 is transmitted by a single transmitter. In this embodiment, the video is distributed nationally, for example, but the data is distributed only locally. This allows the video to have different procedures for different regions. In this embodiment, the range of the transmitter transmitting video 170 is wider than the range of the transmitter that is part of the multiple transmitters transmitting data 160.
[0032]
In the previous two embodiments, care must be taken in synchronizing the data 160 with the video 170 so that the procedures defined in the data are correctly applied to the corresponding parts of the video stream.
[0033]
Here, reference is made to FIG. In the illustrated embodiment, the computer 140 may be, for example, a broadcast source 180 such as a cable, microwave, satellite, etc., a computer such as a notebook 185, a network 190 such as the Internet, an analog and And / or receiving a video file from a digital data source. These may further include smart mobile phones, PDAs, and the like. In the current embodiment, the data received is a video stream. This video stream is received by the demultiplexer 205. Demultiplexer 205 separates this video stream into an active video procedure data stream and a raw video stream. The former applies to the active stream engine 225 and the latter applies to the decoder 210 (decoding to a compressed video format if necessary). The output of decoder 210 is applied to a process 215 that checks the profile recorded on computer 140. This profile records data characterizing the viewer. If the profile matches the current video, the procedure is applied to a process 225 that generates a modified video stream in response to the profile data. If the profile does not guarantee modification of the video stream, the original decompressed video is output. This output stream is applied to a variety of different output devices, such as a broadcast transmission 180, a computer 185, a television or monitor 131, and a data record 195. The output device may further include the VTR shown in FIG. The example shown in FIG. 2 is merely illustrative.
[0034]
Demultiplexers may receive analog or digital signals. One example of an analog signal is an NTSC signal from a television broadcast. In this case, the common place where data is arranged is the VBI. In this case, the demultiplexer extracts the data in the VBI from the raw video stream and applies it to the active stream engine 225. The active stream engine simply executes the applied procedure. An active video procedure may consist of more codes than can be included in one VBI. In this case, the active stream engine 225 is programmed to capture the entire procedure. The end of this whole procedure is usually indicated by a delimiter, such as the end of a file marker. The delimiter in this case indicates that the data following the delimiter represents a procedure to be performed. Any suitable protocol may be defined to accumulate procedures in computer memory before arriving at a video segment that must be applied. If the video data file is digital, the procedural data may be packaged in any suitable manner, such as as a header, interleaved in the data file. For streaming data, this procedure means that the video may be transmitted as a header file or small parcel. This is because the video is buffered so that playback can be started immediately without waiting for the entire procedure or series of procedures accumulated in time series to be loaded. The latter accumulation method assumes that the videos to which they apply are not loaded before the procedure is loaded. Alternatively, this procedural data may be distributed through a video file and executed by an interpreter functioning on computer 140. (The interpreter, for example, upon receipt of a command-line instruction of a text-based operating system shell, such as MSDOS®, or a command mode of a database program, such as dBase III®, without precompilation. A program that executes instructions.)
Once the above procedure is accumulated in memory, it can be performed in response to the video file's profile data and indicators. Please refer to FIG. Indicators for video files or data streams can take a variety of forms. Several different examples are shown in FIG. FIG. 5 shows a file or streaming media data 501 when time advances in the illustrated direction. Audio sequence Aud ₁ Can function as a marker. In that case, the sound classifier moves on the audio track until some feature is detected. Similarly, the image Img ₁ , Img ₂ , Or other signal portions may be recognized to identify portions of the video stream. The sub-image SI of the frame image 510 may also be classified to trigger an event.
[0035]
M ₁ , M ₂ , And M ₃ Markers such as can be written to the file. In an analog file such as NTSC, this marker can be placed on the VBI. The time from the beginning of the data start point is tracked and the time ₁ And T ₂ Etc. may be used to represent a portion of a video stream. Again, before some aspects of the video stream are applied to the stream, procedure 500 may be embedded in the stream. For example, this procedure 500 ₃ Rather than the sequence shown in ₁ And T ₂ (Note that time is flowing up the page).
[0036]
Note that the indicator is not necessary if it is ready to execute as soon as the instruction is received. One form of indicator is simply a location marker. In the analog stream, this marker may take the form of a watermark or icon that is recognized in a portion of the video image or data multiplexed into the VBI. In a digital stream, this marker may be any suitable symbol or an indication of a temporal position. Of course, in digital embodiments, this marker need not necessarily occupy a position in the stream that is consistent with the application of the procedure. May occupy.
[0037]
Decoder 210 is any defined process required to access the video data, such as decompression, decoding, unpacking, and decoupling. The details of this process are not important to the practice of the present invention.
[0038]
A profile may simply include various data, such as information about a user's identity, preferences of the user or a group of users (such as a housewife). For example, the preferences may indicate that the user group is a housewife with very young children. This active procedure can query the user before displaying highly violent or sexual themes. Then, if there is no response, the potentially unpleasant theme can be masked or erased. The profile database may include theme preferences that the procedure uses to filter selectable attributes. For example, imagine a video file that contains many different video files, all of which are aggregated to view a particular video. This profile filters them and presents one or more video files selected for viewing.
[0039]
As mentioned above, in one embodiment, the above procedure consists of commands operating on separate parts of the video stream. This execution environment is stateless so that any finite number of such parts are always copied using procedures applicable to them. The information does not persist between the separable parts of the execution environment unless the attached procedure cannot generate the information itself if it cannot find it. In this frame-by-frame stateless embodiment described above in the Disclosure of the Invention section, the demultiplexer continuously generates commands as they are received. This command can be executed immediately by the demultiplexer or adapted to a marker or unique indicator in the video stream.
[0040]
Here, reference is made to FIG. In another embodiment, the active procedure is applied to a compressed video stream. Decoding 310 is performed only after this active procedure has been applied to the raw video stream. In this example, the video is described as being compressed, but may be encrypted, bundled, or otherwise encoded. Again, although not shown, the profile data may be provided to the active stream engine to create a procedure in response to the profile data. In FIG. 4, the active procedure is sent or provided to the active stream engine 425 in parallel. For example, in a broadcast environment, a parallel transmission is created and the video is modified accordingly. Again, synchronization can be ensured by adapting the execution to markers or other indicia in the video stream. In this example, an important advantage is the short life of the procedure code. The video is constantly updated according to the latest procedure supplied by the source of the active procedure.
[0041]
In environments where the requirements of statelessness are not important, the active procedural data may be located in a location independent of the portion of the video to which they apply. However, the only requirement is that streaming sources, such as TV broadcasts and Internet streaming files, must load this procedure before it is needed. This procedure can be broken down, all of which must be accumulated in memory before it is needed. Then, the procedure code may be discarded. This code and the discard trigger event can be encoded into the procedure itself.
[0042]
The code definition procedure always includes at a high level the elements that define complex, predetermined procedures, or at a low level, the elements that define small incremental procedures that must be assembled in order to take useful action. Absent. The following are examples of the types of commands that can be executed by the appropriate API to modify the media data stream.
[0043]
Playback of blocks b0 to b1: Play back a video block sequence from block b0 to block b1. Draw x1, y1, x2, y2, W, C: Draw a superimposed line at the designated coordinates at the designated weight and color.
[0044]
Rectangle drawing x1, y1, x2, y2, W, C, F: A superimposed rectangle is drawn with the specified boundary weight, color, and fill at the specified coordinates.
[0045]
Applying filters (c11, c12, c13, c21, c22, c23, c31, c32, c33) x1, y1, x2, y2: Apply the filter to the zone defined by the specific row example on the specific area.
[0046]
path: // filmname. Include video segment in vid: Define another stream and stop inserting video into the other stream.
[0047]
It will be apparent to one skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention may be embodied in other specific forms without departing from the spirit or the essential attributes thereof. Will. Therefore, the present embodiments are to be considered in all respects as illustrative and not restrictive, and the scope of the present invention is indicated by the appended claims rather than by the foregoing description. Therefore, all modifications falling within the equivalent meaning and scope of the claims are intended to be embraced therein.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a user environment in which the present invention can be used.
FIG. 2 is a block diagram of the present invention wherein video data from a source is demultiplexed and decoded to extract data defining a procedure, and the procedure is performed to modify the video in response to a profile. It is a figure showing one embodiment.
FIG. 3 demultiplexes video data from a source to extract data defining a procedure, executes the compressed file modified by the procedure in response to a profile, and decodes the modified compressed file. 1 is a diagram showing an embodiment of the present invention.
FIG. 4 demultiplexes video data from a source, obtains data defining a procedure from another source, decodes a video file, and the procedure modifies the video in response to a profile. FIG. 1 is a diagram showing an embodiment of the present invention executed for the following.
FIG. 5 illustrates a canonical representation of a video file to illustrate features of certain embodiments of the present invention.

Claims (23)

A method of modifying a media information stream, the method comprising:
Incorporating into the media information stream a definition of a procedure applied to modify a portion of the media information stream;
Performing the procedure at the point of playback, recording, or retransmission of the media information stream. The method of claim 1, wherein
The procedure includes a plurality of steps,
A method wherein each of the plurality of steps is included in the media information stream adjacent to a portion of the media information stream to which each step is applicable. The method of claim 1, wherein
The method of claim 11, wherein the performing step comprises modifying a media information portion of the media information stream. The method of claim 1, wherein
The method of claim 11, wherein the performing comprises providing a command to an interpreter on a computer at the point of playback, recording, or retransmission. The method of claim 1, wherein
The performing step includes inputting a command to an interpreter;
The interpreter is programmed to execute the command immediately upon the input;
The method wherein the interpreter is executed continuously on a computer at the point of playback, recording, or retransmission. The method of claim 5, wherein
The method of claim 1, wherein in the execution environment, the interpreter is stateless because there are no variables persisted from one command to the next. The method of claim 5, wherein
The execution environment of the interpreter is stateless, since there are no variables applied from one command group preceding the video segment to the next command group applied to modify the video segment; how to. A method of modifying a media information stream, the method comprising:
Synchronizing at least one command present in the data stream and indicating a procedure with the media information stream;
Invoking the procedure in response to the command at a playback point of the media information stream so that the procedure modifies the media information stream;
The method of claim 2, wherein the synchronization allows the procedure to operate on a designated portion of the media information stream. A media information stream having streaming video data,
The streaming video data has indicia located at various points of the streaming video data;
The indicia indicates the command such that when the media information stream is applied to an interpreter, the interpreter can modify the streaming video data in response to the command. Media information stream. The media information stream according to claim 9, wherein:
The media information stream characterized in that the interpreter is stateless such that a sequence of commands is executed and the same virtual machine state is initiated as all other commands. The media information stream according to claim 9, wherein:
The media information stream, wherein the modifying comprises providing a filter on at least one frame of the streaming video data. The media information stream according to claim 9, wherein:
The streaming video data also includes a marker,
The media information stream, wherein the command is executable according to the marker. The media information stream according to claim 9, wherein:
The media information stream, wherein the command is responsive to characteristics of the streaming video data. A broadcast system,
A first transmitter capable of outputting a media information stream;
A second transmitter capable of outputting a procedural data stream synchronized with the media information stream,
The procedural data stream includes data indicating at least one procedure that, when executed, is capable of modifying the media information stream;
Synchronizing the media information stream with the procedural data stream such that a procedure defined in the procedural data stream is applied to a designated portion of the media information stream. The system according to claim 14, wherein
The second transmitter has a transmitter matrix,
The system of claim 5, wherein each of the transmitters in the matrix has a range that is less than a range of the first transmitter. The system according to claim 15, wherein
The system of claim 5, wherein the matrix transmitters transmit different data. The system according to claim 14, wherein
A system, wherein the initial state of a state machine that corresponds to every command sequence in the procedural data stream and defines a procedure to be applied to successive portions of the media information stream is the same. An apparatus for receiving and modifying a media information stream, the apparatus comprising:
A demultiplexer having an input for receiving the combined data stream and outputting a media information stream and a procedural data stream;
A controller having an input and an output,
The apparatus, wherein the controller is programmed to receive the media information stream and the procedural data stream and modify the media information stream in response to the procedural data stream. 19. The method of claim 18, wherein
The procedural data stream includes a plurality of commands;
Each of the plurality of commands is included in the composite data stream adjacent to a portion representing a portion of the media information stream to which each of the steps is applicable, so that the procedural data stream is synchronized with the media information stream. Is taken. 19. The method of claim 18, wherein
The controller is programmed to generate an interpreter process that executes commands in the procedural data stream to achieve a state machine having cycles synchronized according to the configuration of the composite data stream. A method characterized in that: 19. The method of claim 18, wherein
The method wherein the controller is programmed to implement a continuously executed interpreter process such that a command in the procedural data stream is executed as soon as it is received by the controller. 22. The method of claim 21, wherein
A method wherein the interpreter's execution environment is stateless because there are no variables persisted from one command to the next. 22. The method of claim 21, wherein
The execution environment of the interpreter is stateless, since there are no variables applied from one command group preceding the video segment to the next command group applied to modify the video segment; how to.

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