JP2008072586A - Digital av stream reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easy-to-operate digital AV stream reproducing apparatus surely executing a fast-forward reproducing operation with easy-to-read closed caption. <P>SOLUTION: The digital AV stream reproducing apparatus is provided with a data broadcast data transmission function containing BML document describing procedures for switching closed caption display mode of a receiver, and a function for automatically switching the closed caption display mode of the receiver to the display mode by transmitting the data broadcast data in addition to the image data and the closed caption data. The digital AV stream reproducing apparatus ensuring an easy-to-read closed caption is provided by obtaining the number of characters and the contents of characters of closed-caption sentence included in the original stream, determining and displaying the closed caption display time based on the contents. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a digital AV stream playback apparatus or a digital AV stream recording / playback apparatus.

  In line with the recent development of a barrier-free society, the enhancement of broadcasting infrastructure has been enhanced so that subtitle information can be embedded in broadcasts as much as possible so that even people with handicap can enjoy TV without inconvenience. It is being advanced. In accordance with this, a configuration of a device having a function of displaying subtitle data not only during normal playback but also during fast-forward playback has been proposed in a digital broadcast recording and playback device. Such a function is beneficial not only for a person with a handicap in hearing but also for a healthy person in that a program can be quickly viewed in a shorter time than normal playback.

  Conventionally, a recording / playback device has been provided with a “fast forward playback function with sound” that plays back sound and video at a speed faster than the speed at the time of broadcast recording (eg, about 1.3 times the speed). However, if the playback speed is increased further, for example, double speed or triple speed, the voice is too fast to be heard and the contents cannot be understood.

However, since fast-forward playback with subtitle display enables character recognition in a relatively short time, the content can be understood even if playback is performed at a speed faster than the playback speed of the fast-forward function with audio. A quick look at time is possible. An example of a device having such a function is disclosed in Patent Document 1. Video data and additional subtitle-related data are extracted from the digital signal read from the recording medium, and data relating to display of subtitle-related data is updated and transmitted to the digital interface.
JP 2004-32607 A JP 2001-24963 A JP 2001-45408 A IEEE Std 1394-1995 IEEE Standard for a High Performance Serial Bus ISO / IEC 13818-1 Information technology-Generic cording of moving pictures and associated audio information: System 1394 Trade Association AV / C Digital Interface Command Set General Specification version4.2 TA Document number 2004005 AV / C Tape Recorder / Player Subunit Specification 2.4 September 1, 2004 TA Document number 2002001 AV / C Disc Subunit General Specification 1.2 ARIB STD-B24 Data broadcasting encoding and transmission system in digital broadcasting ARIB STD-B21 Digital Broadcast Receiver-Desirable Specifications

  However, the configurations of the devices disclosed so far have problems (first and second problems) in the following points.

  First, the first problem is that existing digital broadcast receivers cannot perform special playback with captions stably.

  The subtitle display of the playback image is not displayed on the screen unless the setting “subtitle display mode” of the digital broadcast receiver that displays the playback image is set to “display”. The subtitle display mode of the receiver is normally switched by the user with a remote controller. For normal playback, watch without subtitle display, and for fast forward playback, display subtitles for viewing, and the user can set the subtitle display mode of the receiver to “No subtitle display” at the start of normal playback. Sometimes it is necessary to switch to “with caption display”. That is, in a digital AV stream playback apparatus that performs special playback (for example, fast-forward playback) that sends caption data together with video data, when the user views the caption display, the caption display mode of the receiver is manually set to “displayed”. There was a problem that it was cumbersome to switch.

  In addition, most digital broadcasting receivers that are currently on the market do not display subtitles unless they are “normally playing”, and even if the user tries to perform “fast-forward playback with subtitles display”, When the AV stream playback device returns the state of “fast forwarding”, the subtitle is not displayed. As a result, there are many cases in which caption display is not performed well for the user.

  Furthermore, as a second problem, when watching fast-forward video with subtitle display, the subtitle display disappears before reading the displayed subtitles in a scene where subtitles with many characters are displayed continuously. In addition, there was a problem that it was difficult to understand the contents of the program due to the large gap between the background video and the subtitles.

  Patent Document 1 discloses a method for shortening the subtitle display time in accordance with the fast-forward speed of fast-forward playback and a method for continuing the previous subtitle display until the next subtitle display. However, in a scene where the number of characters in the subtitle is large, there is a disadvantage that the subtitle disappears before the user can read the subtitle, or the subtitle is switched to the next subtitle.

  Patent Document 2 discloses a method of increasing the caption display time by enlarging the caption display area and scrolling the caption display. However, with this method, there is a problem that the display scene of the video and the display content of the subtitles are deviated, making it difficult for the user to recognize the program content.

  Patent Document 3 describes an operation example in which the playback speed is switched from normal speed playback to high speed playback depending on the presence or absence of subtitles. This method partially solves the second problem in the sense that subtitle display is ensured, but only the note symbols indicating that BGM is flowing in the subtitles inserted into the program. May be displayed for a long time. In such scenes where subtitles are inserted, normal speed playback is performed, and effective quick playback cannot be performed.

  As described above, in the methods disclosed so far, the subtitle display during the fast-forward operation with subtitles has a short display time even though the number of subtitle characters is large, and conversely, the display time is long although the number of subtitle characters is small. Thus, it was not easy for the user to read.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a digital AV stream playback apparatus that can easily and reliably perform a fast-forward playback operation with subtitles that allow easy reading of characters.

  In order to solve the above-mentioned problems, a digital AV stream reproducing apparatus according to the present invention includes storage means for storing AV data, caption analysis means for reading caption data from the storage means and analyzing the contents thereof, and the caption analysis means. Display picture setting means for selectively reading video picture data from the storage means, data broadcasting data generating means for outputting data for data broadcasting, subtitle data, video picture data, for data broadcasting Special AV stream generation means for processing data, multiplexing and outputting as an MPEG transport stream, and digital interface communication means for outputting the output of the special AV stream generation means on a digital interface, and selectively extracting them Subtitles when sending video picture data The chromatography data and data broadcast data and outputs the multiplexed.

  The data broadcast data generating means preferably outputs BML data having a function of enabling a caption display function of a digital broadcast receiver for displaying video.

  The BML data having a function for enabling the caption display function of the digital broadcast receiver output from the data broadcasting data generating means includes a function for enabling a function for restoring the caption display when an event message is received. It is desirable that

  A packet rewriting / reproducing unit that rewrites and transmits part of the stream data stored in the accumulating unit, and the digital interface communication unit outputs the outputs of the special AV stream generating unit and the packet rewriting / reproducing unit to the digital interface When the stream output above and stored in the storage means is played back at a normal speed, it is desirable that the packet rewriting / playback means invalidates the caption data and outputs the stream.

  In addition, there is an operation state response unit that responds to an operation state inquiry request of the device, which is performed via the digital interface communication unit, and the operation state response unit is configured to transmit video data and subtitle data in a multiplexed manner. It is desirable to respond to the inquiry about the operating state that “normal playback operation is in progress”.

  The display picture setting means preferably increases or decreases the display time of the caption text based on the analysis result of the number of characters / character contents of the caption text performed by the caption analysis means.

  The display picture setting means preferably changes the number of skipped pictures to be extracted from the original video stream in accordance with the display time of the caption text.

  Further, it is preferable that the trick-play AV stream generating means issues a caption control data packet prior to a caption sentence packet at the start of a special playback operation with caption.

  As described above, according to the present invention, it is possible to provide a digital AV stream reproducing apparatus that can easily and reliably perform a fast-forward reproduction operation with subtitles that allow easy reading of characters.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a configuration diagram of a digital AV stream playback device having a function of superimposing subtitle data on a video stream and sending it. The internal process is depicted as a block diagram in blocks.

  Reference numeral 10 denotes a digital AV stream playback device. Reference numeral 11 denotes a digital broadcast receiver connected to the digital AV stream reproducing apparatus 10 via a digital interface. Reference numeral 12 denotes a TV receiver that displays an output video of the digital broadcast receiver 11. Reference numeral 13 denotes a remote control device for controlling the digital AV stream playback device 10.

  Reference numeral 100 denotes storage means for storing a digital broadcast stream. Specifically, a hard disk, an optical disk, a large-capacity memory, and the like. Reference numeral 101 denotes subtitle analysis means for acquiring subtitle data from the storage means 100 and analyzing the contents thereof. Reference numeral 102 denotes display picture setting means for selecting and outputting a picture to be displayed from the storage means 100. Reference numeral 103 denotes data broadcasting data generation means for outputting data stored in advance in a memory (not shown) in the system as packet data for data broadcasting.

  104 multiplexes the subtitle packet data output from the subtitle analysis unit 101, the video packet data output from the display picture setting unit 102, and the data broadcast data output from the data broadcast data generation unit 103, forms a transport, and outputs the data. Special replay AV stream generating means.

  Reference numeral 105 denotes an operation state response unit that responds to an operation state inquiry command received from the digital broadcast receiver 11. Reference numeral 106 denotes a packet rewriting / reproducing unit that, when reproducing the stream data recorded in the accumulating unit 100 at a normal speed (the same speed as when recording), transmits the data while rewriting part of the data. Reference numeral 107 denotes digital interface communication means for communicating with the digital broadcast receiver. Specifically, IEEE 1394, etc. In the description of this embodiment, the interface is IEEE 1394 described in Non-Patent Document 1, the stream of AV data is MPEG 2 described in Non-Patent Document 2, and the command to be exchanged is: The explanation is based on the assumption of the AV / C command described in Non-Patent Document 3.

  Reference numeral 108 denotes remote control signal receiving means for receiving a signal from the remote control device 13. A control unit 109 receives an operation request from the remote control signal receiving unit 108 and controls each unit of the digital AV stream reproducing apparatus 10.

  Reference numeral 120 denotes digital interface communication means for exchanging digital AV streams and commands with the digital AV stream playback apparatus 10. Reference numeral 121 denotes data broadcast execution means for executing data broadcast. Reference numeral 122 denotes display means for displaying video and subtitles of the received digital AV stream.

  FIG. 2A is a flowchart showing a flow of operations of the digital AV stream reproducing apparatus 10 shown in FIG. FIG. 2B shows the flow of data broadcast processing executed on the digital broadcast receiver 11 connected by a digital interface.

  Hereinafter, the operation of the digital AV stream reproducing apparatus of the present invention will be described along the flow of FIG.

(Start of special playback operation with caption display ST1)
After the system is started (ST1), the user requests the digital AV stream playback device 10 to start the special playback with subtitles by using the remote controller 13 or by a command issued from the digital broadcast receiver 11 or the like. (RQ1). This “special playback with subtitle display” specifically refers to “fast-forward playback with subtitle display” described in the background art section, for example. In addition to this, “reverse fast-forward with subtitle display” It also includes “playback” and “slow playback with subtitle display”. In the following description, these operations are expressed as “special playback with caption display”.
(Operation status response set ST2)
The control unit 109 that has received the request sets an operation state response in the operation state response unit 105 (ST2). With this setting, the operation state response means 105 responds to the operation state inquiry command from the digital broadcast receiver 11 during the special reproduction period with caption display, and the operation state is not “fast forward playback” or “slow playback”. Normal speed playback ”is notified. This is because most of the existing digital broadcasting receivers do not display subtitles on the screen unless they are in the “normal playback” state.

  The exchange of operation status inquiries performed between the digital broadcast receiver 11 and the digital AV stream playback apparatus 10 is 1394TA (1394 Trade Association) described in Non-Patent Document 3 when the digital interface communication means 107 or 120 is IEEE1394. The AV / C (Audio Video Control) command defined by Details of the AV / C commands exchanged here are described in detail in Non-Patent Document 4, Non-Patent Document 5, and the like.

  When the digital AV stream playback device 10 is operating as a VCR device, the digital broadcast receiver 11 uses the TransportStatus command in the VCR command described in Non-Patent Document 4 to operate the digital AV stream playback device 10. Contact us. The operation state response means 105 responds to this inquiry by setting a code meaning “Playing”.

Further, when the digital AV stream playback device 10 is operating as a disk device, the operation status of the digital AV stream playback device 10 is determined by the digital broadcast receiver by StatusDescriptor in the disk command described in Non-Patent Document 5. Will be notified. The operation state response means 105 performs an operation of setting a code meaning “playing in progress” in the StatusDescriptor.
(Special Replay with Subtitle Display-ST3 Packet Advance Sending Operation-ST31)
Subsequently, the digital AV stream reproducing apparatus 10 performs a packet advance transmission operation. In the present embodiment, this is an operation performed by the special AV stream reproduction unit 104 in response to a request from the control unit 109.

The AV data for special playback with caption display is read from the storage means 100, and information necessary for the digital broadcast receiver 11 receiving the stream to correctly recognize the caption information is sent in advance. Specifically, when the stream to be sent is an MPEG2 transport stream defined by ISO / IEC13818,
PAT (Program Association Table) transmission PMT (Program Map Table) transmission is performed, and then a caption management data packet is transmitted.

  Here, the caption management data packet will be described. Non-patent document 6 describes a transmission method of caption information in Japanese digital broadcasting.

  According to Non-Patent Document 6, it is recommended that subtitles and character supergroups are grouped by data group configuration and transmitted by independent PES. The data structure of this data group has a 6-bit data group identification (data_group_id) at the head, and indicates the distinction between the types of caption management data and caption text data. The caption service is transmitted by the caption management data and zero or a maximum of eight caption sentence data. In the caption management data, information such as TMD, OTM, DMF, ISO_639_language_code is transmitted. On the other hand, in the subtitle sentence data, the TMD, the display character string control code, and the character code are transmitted. The caption management data packet transmitted after the PAT / PMT described above is a packet for transmitting the caption management data. In order for the digital broadcast receiver 11 to display the caption text in the stream on the screen, it is necessary to receive the packet including the caption management data before receiving the packet including the caption text data, and recognize the caption management data packet. This is because it is necessary to receive the PMT / PAT before that.

  The special broadcast AV stream reproducing means 104 according to the present invention performs such transmission, so that the digital broadcast receiver 11 can correctly recognize the packet for transmitting the caption text data, and the special reproduction with caption display is started. In some cases, the first problem that special playback with caption display cannot be performed stably, such as no caption text being displayed, can be solved.

According to the above-mentioned ARIB recommended specifications (Non-Patent Document 7), it is required to insert SIT (Selection Information Table) into the digital AV stream output on the high-speed digital interface. In order to operate the receiver 11 reliably, an SIT may be inserted after the PAT / PMT.
(Special replay with subtitle display-ST3 Data broadcasting transmission operation for subtitle display control-ST32)
In this embodiment, the control means 109 is an operation performed by controlling the data broadcasting data generation means 103.

  A packet including a data broadcast BML (Broadcast Markup Language) document stored in advance in storage means 100 or a non-volatile memory (not shown) is read, and data broadcast data is transmitted. The BML document described in this data broadcast includes a function for controlling the caption display of the digital broadcast receiver 11. FIG. 2B shows the processing flow of the data broadcasting using the BML function defined in the non-patent document 6.

In ST102, the data broadcast activated in ST101 is
getCCDisplayStatus ()
getCCLangageStatus ()
The subtitle display state of the receiver is acquired using a function such as In ST103,
writePersistentString ()
The subtitle display state of the receiver is saved using a function such as In ST104,
setCCDisplayStatus ()
The subtitle display state of the receiver is set using a function such as ST105 is an event message reception waiting state. When an event message is received, the process proceeds to ST106.
readPersistentString ()
If you get the subtitle display settings before startup using a function such as
setCCDisplayStatus ()
Is used to return to the original state.

The data broadcast data generation means 104 in the present invention transmits such a data broadcast, so that the user can operate the remote control of the digital broadcast receiver 11 to change the subtitle display mode of the receiver. Thus, it is possible to view the special playback screen with caption display without taking the trouble of doing so, and it is possible to solve the first problem that the special playback with caption display is not performed stably. Note that it is more preferable that the data broadcast output from the data broadcast data generation unit 103 is given an “Invisible” attribute that does not appear on the screen even during execution because it does not hinder the user from viewing the screen.
(Special replay with caption display-ST3 Picture data transmission operation-ST33)
(Special replay with subtitle display-ST3 subtitle data transmission operation-ST34)
In the present embodiment, the control unit 109 is an operation performed by controlling the caption analysis unit 101 and the display picture setting unit 102. The digital AV stream reproducing apparatus 10 simultaneously performs the picture data transmission operation (ST33) and the subtitle data transmission operation (ST34) while performing the above-described data broadcast transmission operation (ST32) for subtitle display control. .

  The processing flow of ST33 and ST34 will be described using the flowchart shown in FIG.

  After starting special playback with subtitle display (ST200), subtitle analysis means 101 searches for subtitle data for the digital stream stored in storage means 100, and display picture setting means 102 searches for a picture ( S201).

  When a caption packet is found (C1), the caption analysis unit 101 performs a caption analysis transmission operation (ST202). In this subtitle analysis and transmission operation, the number of display characters of subtitles and the content of characters included in the subtitles are acquired from the packet in which the subtitle sentence data is described (ST204), and the subtitle display in the special playback operation with subtitle display is obtained from the result. The time and the number of picture skips for video display are determined as special playback parameters with subtitles and notified to the display picture setting means 102 (ST205).

  Here, the number of picture skips notified by the caption analysis unit 101 to the display picture setting unit 102 will be described. When the digital AV stream stored in the storage means is MPEG2, the video has a GOP (Group of Pictures) structure. This is a group of a plurality of continuous screens, and MPEG inter-frame prediction is independent with this as a unit. Each GOP normally includes one I picture (intra picture). During special playback, this I picture is extracted from the stream and sent out for fast-forward playback. Since this GOP is normally sent out at a cycle of about once every 0.5 seconds, if the I picture display time is constant, the fast-forward speed is determined by how many I pictures to display are selected. Will be. For example, in a fast-forward operation in which one set of GOPs is sent every 0.5 seconds and I-pictures are sent every 0.5 seconds, if every other I-picture is selected and sent out, double-speed playback fast-forward video Is displayed. If every second frame is selected and sent, it is displayed as a fast-forward video for 3 × speed playback. The “picture skip number” output from the caption analysis unit 101 to the display picture setting unit 102 indicates this value.

  Thereafter, the subtitle analysis means 101, when the analyzed subtitle sentence data includes a control character code for designating the erasure time in the display character string, the erasure time is calculated as the calculated special reproduction time. Rewriting to the caption display time, the packet for transmitting the caption text and the packet for transmitting the caption management data are output to the trick-play AV stream generating means (ST206).

  On the other hand, the display picture setting unit 102 that has received the special playback parameter searches for a picture in the storage unit 100 based on the designated skip number, performs transmission picture determination, and generates a special AV stream for the packet of the picture. This is output to the means 104 (ST203).

  In the processing of ST204 in this operation, the caption analysis means 101 has a function of determining the caption display time based on the number of characters displayed on the screen and the content of the caption text. For example, the determination by the number of characters is to shorten the display time if the number of characters in the subtitle sentence is small, and to increase the subtitle display time if the number of characters is large.

  In addition, the determination based on the content of the subtitle sentence determines the display time based on the number of characters if it is a normal character, and if the subtitle sentence is a specific character string, extracts the subtitle display time when played at normal speed, Based on the time, the display time for special playback is determined. For example, if the character string of the subtitle sentence is only a note symbol, this subtitle is displayed when the theme song at the beginning or end of the program is broadcast. In such a scene, since the displayed video has the same content every time, even if it is played back at a high speed, the content of the program is not hindered. Therefore, in a scene where the text of the subtitle text is a musical note symbol, the subtitle display time is calculated so that the subtitle display time is calculated and the display time is reduced by a certain ratio such as half or one third. It is what determines the time.

  In the process of ST201, when an I picture is found before a caption packet is found (C2), in ST203, a picture to be transmitted is determined with a preset value.

  By repeatedly executing the subtitle display control BML document transmission operation (ST32), the picture data transmission operation (ST33), and the subtitle data transmission operation (ST34) as described above, the subtitle display control BML document transmission operation (ST32) The respeed can be changed, and the time for displaying subtitles can be changed.

  As a supplement, the effects of the picture data transmission operation-ST33 and subtitle data transmission operation-ST34 of the present invention on the subtitle and picture transmission operation will be described with reference to FIG. FIG. 4 is a diagram showing the relationship between “subtitle display” and “display picture” in normal playback operation and “subtitle display” and “display picture” in special playback with subtitle display.

  401 indicates the transmission timing of subtitles and video when normal playback is performed. Reference numeral 403 indicates subtitle display, and reference numeral 404 indicates an I picture arrangement (GOP arrangement). The lower 402 shows the operation when special playback with caption display of the present invention is performed, 405 shows a picture to be displayed from the 404 pictures, and 406 shows the special playback operation. Shows picture and subtitle times. One scale corresponds to sending out an I picture.

  In 402, a short caption text shortens the caption display time for special playback with caption display, and the picture to be transmitted at the same time is also selected at a rough interval. Where the caption text is long, the caption display time to be displayed in special playback with caption display is lengthened, and the picture to be transmitted is selected at fine intervals.

  By the operation as described above, in the present invention, the caption is displayed for a time corresponding to the content of the number of characters of the caption. In addition, the image displayed on the screen during subtitle display is an image of the portion where the subtitle is displayed, and the effect that the positional deviation between the special subtitle display with subtitle display and the background video can be reduced. There is.

In the above description, in the display picture setting operation ST203, the picture to be displayed has been described as an I picture. However, in order to obtain a smooth playback image, not only an I picture but also a P picture may be transmitted. Of course it is possible.
(Special stop operation with caption display ST4)
Operation when special re-operation stop request is issued (RQ2) by remote control operation from user or command from digital broadcast receiver during special re-operation with subtitle display (ST3) Will be described.

  When the stop request is received, the data broadcast data generation unit 103 performs an operation of notifying the digital broadcast receiver 11 of an event message via the digital interface communication unit 107.

  By this operation, the receiver subtitle display mode restoration process ST106 shown in FIG. 2B is performed, the subtitle display mode of the digital broadcast receiver 11 is returned to the start-up state (ST101), and the data broadcast ends ( ST107). Thereafter, the digital AV stream playback device 10 stops (ST5).

  With the above special stop operation with caption display, it is possible to return to the state before the special playback with caption display without changing the setting of the digital broadcast receiver 11 by the user. With the configuration as described above, the setting of the caption display mode of the digital broadcast receiver 11 can be automatically performed, and the special reproduction operation with caption display can be stably performed.

  However, in rare cases, digital broadcast receivers that exist in some markets may not work well. In the special restart operation with subtitle display (ST4) described above, the subtitle display mode of the receiver is changed by data broadcasting being executed on the digital broadcast receiver 11, but some digital broadcast receivers 11, the data broadcast is stopped before the data broadcast changes the subtitle display mode of the receiver, and eventually the data broadcast execution means 121 operates in a mode with subtitle display. . If a normal playback operation is subsequently performed in this state, captions are displayed, and a user who does not desire caption display needs to operate the remote control to change the caption display mode.

  The packet rewriting / reproducing means 106 in FIG. 1 solves this problem. When the user sets an operation of “not displaying subtitles during normal reproduction” (the setting means is not shown), the accumulating means When the stream is normally played back from 100, the subtitle data is deleted or invalidated from the stream. Specifically, at the time of normal reproduction, a packet having the PID of the caption text is selectively removed or invalidated from the original stream. Alternatively, during normal playback, the description in the PMT section of the PMT is rewritten so that the digital broadcast receiver cannot refer to the packet having the PID of the caption sentence.

  With the operation described above, automatic switching can be performed in the special playback operation with subtitles and the normal playback operation without the user changing the subtitle display setting of the receiver.

  Even in some digital broadcasting receivers that are slow to execute data broadcasting, the subtitle display is turned ON / OFF as intended by the user by combining the data broadcasting data generation means 103 and the packet rewriting / reproducing means 106. It is possible to perform special playback with caption display stably.

  In the present embodiment, the digital AV stream reproducing apparatus is described. However, the same applies to the apparatus having the recording function at the same time.

  The digital AV stream playback apparatus according to the present invention can simultaneously transmit subtitle information during fast-forward playback, and does not require the user to manually switch the subtitle display mode of the receiver to display, in addition to subtitle and fast-forward video. Since it is possible to provide an AV stream reproducing apparatus with little positional deviation, it is effective for a digital AV stream reproducing apparatus.

The block diagram of the digital AV stream reproducing apparatus provided with the function which superimposes subtitle data on a video stream, and transmits it in embodiment of this invention Operation flowchart of the digital AV stream playback device when performing special playback with caption display Operation flowchart of caption analysis means 101 and display picture setting means 102 Diagram showing the relationship between "subtitle display" and "display picture" in normal playback operation and "subtitle display" and "display picture" in special playback with subtitle display

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Digital AV stream reproduction apparatus 11 Digital broadcast receiver 12 Television receiver 101 Subtitle analysis means 102 Display picture setting means 103 Data broadcast data generation means 105 Operation state response means 106 Packet rewrite reproduction means

Claims (8)

Storage means for storing AV data;
Subtitle analysis means for reading subtitle data from the storage means and analyzing the contents thereof;
Display picture setting means for selectively reading video picture data from the storage means based on the analysis result of the caption analysis means;
Data broadcasting data generating means for outputting data broadcasting data;
Special AV stream generation means for processing caption data, video picture data, data broadcasting data, multiplexing and outputting as an MPEG transport stream,
A digital interface communication means for outputting the output of the special AV stream generating means on a digital interface;
A digital AV stream reproducing apparatus, wherein subtitle data and data broadcasting data are multiplexed and outputted when selectively transmitting video picture data. 2. The digital AV stream reproducing apparatus according to claim 1, wherein the data broadcast data generating means outputs BML data having a function of enabling a caption display function of a digital broadcast receiver for displaying video. The BML data having the function of enabling the caption display function of the digital broadcast receiver output from the data broadcast data generating means includes the function of enabling the function of returning the caption display to the original when receiving the event message. The digital AV stream reproducing apparatus according to claim 2, wherein: A packet rewriting / reproducing means for rewriting and transmitting a part of the stream data accumulated in the accumulating means,
The digital interface communication means outputs the outputs of the special AV stream generating means and the packet rewriting / reproducing means on the digital interface;
2. The digital AV stream reproducing apparatus according to claim 1, wherein when reproducing the stream stored in the storage unit at a normal speed, the packet rewriting / reproducing unit invalidates the caption data and outputs the stream. An operation state response means for responding to an operation state inquiry request of the device, which is performed via the digital interface communication means;
The operation state response means responds to the inquiry about the operation state that “normal playback operation is in progress” when video data and caption data are multiplexed and transmitted. The digital AV stream reproducing apparatus described in 1. 2. The digital AV stream reproducing apparatus according to claim 1, wherein the display picture setting unit increases or decreases the display time of the subtitle sentence based on the analysis result of the number of characters / character contents of the subtitle sentence performed by the subtitle analysis unit. . 2. The digital AV stream reproducing apparatus according to claim 1, wherein the display picture setting unit changes the number of skipped pictures extracted from the original video stream according to the display time of the caption text. 2. The digital AV stream reproducing apparatus according to claim 1, wherein the special AV stream generating means issues a caption control data packet prior to a caption sentence packet at the start of a special playback operation with caption.

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