JP5075383B2 - Subtitle transmission apparatus and subtitle transmission method - Google Patents

Description

  The present invention relates to a caption transmission device and a caption transmission method for digital terrestrial one-segment broadcasting.

  With the start of digital terrestrial television broadcasting, so-called one-seg broadcasting, which is a common name for viewing a broadcast screen on a mobile phone, has started. In 1Seg broadcasting, subtitle broadcasting utilizing the characteristics of digital broadcasting is also performed, and in 1Seg subtitle broadcasting, a video screen of a program and a character screen corresponding thereto are displayed on a display.

FIG. 7 is a system diagram showing a configuration of a conventional one-segment subtitle broadcasting system. Hereinafter, an outline of a processing method of caption data in the one-segment broadcasting system will be described with reference to FIG.
In FIG. 7, a case where the one-segment broadcasting system is provided in the terrestrial HD broadcasting system and performs simulcasting will be described. As equipment on the transmission side, master device 1, VANC subtitle device 2, one-segment subtitle transmission device 300, down converter (hereinafter referred to as D / C) 4, H264 encoding device (hereinafter referred to as H264ENC) 5, and transmission equipment 6 As a receiving side equipment, a one-segment receiver 7 is provided, and as an HD broadcasting system, a terrestrial HD broadcasting HD encoder H5, a transmission facility H6, and a receiver H7 are provided. In addition, there is a local clock 8 as a time information reference device for each device of the master device 1 to the transmission facility 6 to operate at a common timing, and time information is transmitted to each device via a network not shown in the figure, or A predetermined time calibration is performed with an internal clock (not shown) of each device.

  In normal terrestrial broadcasting, a program signal output from the master device 1 that sends out an HD broadcast program is received, and predetermined HD broadcast caption information is multiplexed by the VANC caption device 2 onto the HD broadcast video signal. A TS (Transport Stream) signal is generated. Then, the TS signal output from the VANC caption device 2 is input to the HD encoder H5, and the program (TS) signal multiplexed with the caption data is digitally encoded into the HD signal, and then transmitted with a transmitter (not shown). Broadcast radio waves are transmitted from the facility H6. The receiver H7 receives and decodes the broadcast radio wave, and displays the caption information received as digital data together with the video signal on the screen.

  These system operations and processing procedures are as follows: “ARIB TR-B14 Terrestrial Television Broadcasting Operation Rules” and “Arrib STD-B37 Structure and Operation of Digital Caption Data Transmitted in Auxiliary Data Packet Format” It is prescribed by.

  In the case of one-seg broadcasting, subtitle data prepared for one-seg broadcasting is multiplexed and transmitted as a simulcast in the same manner as the video signal of the HD broadcast signal. For example, the H264 encoded data is decoded by an internal decoder (not shown) by the one-segment receiver 7 using a mobile phone terminal, and the subtitle information is displayed on the monitor screen together with the video.

  Returning to FIG. 7, in the one-segment subtitle broadcast, the output signal of the VANC subtitle device 2 that outputs the program signal of the subtitle broadcast of HD, SD, and analog is input to the one-segment subtitle transmission device 300. The one-segment subtitle transmission apparatus 300 converts a character signal of an input HD broadcast TS signal into subtitle data suitable for a screen of a mobile phone terminal, converts the PES (Packetized Elementary Stream) signal into a superimposed program signal, and outputs the program signal. .

  The converted and output program signal is further down-comparted so as to meet the input conditions with the H264 encoding apparatus 5 for one-segment broadcasting at D / C4. Then, the down-converted signal is input to the H264 encoding device 5 and encoded into a broadcast signal including caption data and video information. The encoded one-segment broadcasting signal is converted into a broadcast radio wave from the transmission facility 6 and received by the one-segment receiver 7 (mobile terminal).

  In one-segment broadcasting, unlike analog terrestrial broadcasting, caption (character) superimposed video is not inserted so as to be superimposed on the video signal. The subtitle data packet (PES) is transmitted on a subtitle data channel different from the video signal channel. Since the display of the received video information and subtitle data must be synchronized, a synchronization method has been proposed to relieve the video signal delay caused by an error during radio wave propagation on the receiving side and the synchronization error between the subtitle data. (For example, Patent Document 1).

  However, as described later, there is a delay time difference between the caption data and the video signal due to the encoding and decoding processes, and therefore, the transmission side must adjust the timing between the two. That is, the video signal input to the H264 encoding device 5 is transmitted from the encoding process and the transmission facility 6 and is delayed by about 2100 msec by the encoding process before being decoded by the receiver 7. Since the subtitle data has a delay time of about 0.5 seconds before it is decoded by the receiver 7 from the H264 encoding device, a delay time difference of about 1.5 seconds occurs.

  The subtitle broadcast signal includes data PTS (Presentation Time) for adjusting the timing between the video signal, audio, and subtitle corresponding to each scene (screen, frame, etc.) so that the subtitle and the video are displayed correspondingly. Stamp) is used. Identification information for taking this correspondence is added to the PTS in accordance with the provisions of “Arrangement and configuration of subtitle auxiliary data packets” of ARIB STD-B37.

  Although detailed description is omitted, if the identification information is schematically described, for example, for a specific scene (for example, a scene “1” and a subsequent scene “2”), a video signal, an audio signal, etc. , PTS-V1, PTS-A1, PTS-C1 for scene “1”, and PTS-V2, PTS-A2, PTS-C2 for scene “2” are assigned to the subtitle data packets as identification information, respectively. Suppose that On the receiving side, corresponding to each scene, the signals are output together so that the subscripts “1” and “2” of the identification information of each signal are combined and displayed on a monitor or the like.

  Originally, in the one-segment receiver 7, since the delay time until the caption data can be output is shorter than the delay time of the video signal, the caption data is held in a caption data buffer or the like, and the video signal is the video signal. Wait until it is input to the buffer before being output.

  However, as will be described later, while the first transmitted caption data (PTS-C1) is on standby, before the video information corresponding to the caption data (PTS-C1) is displayed on the monitor, the next caption data (PTS-C1) is displayed. When C2) is input to the buffer of the one-segment receiver 7, the caption data (PTS-C1) is overwritten with the caption data (PTS-C2) displayed in the next scene.

  As a result, even if the video signal PTS-V1 is displayed on the monitor, the subtitle data PTS-C1 corresponding to the video signal PTS-V1 is overwritten and not saved in the buffer, so that there is no subtitle scene. In particular, overwriting occurs when the subtitle rewriting interval is shorter than the delay time of the video signal. (If the overwritten subtitle is displayed on the monitor without the subtitle and video identification information matching, the scene and subtitle are not aligned.)

8 and 9 are diagrams illustrating examples of correspondence between caption information and video.
FIG. 8 shows the case where the video and the screen are displayed correctly corresponding to each other, and the subtitle information corresponding to FIGS. 8A to 8C is correctly displayed. However, FIG. 9 is a screen display example when the next caption data is input and displayed before displaying the caption to be displayed in FIG. 9B.

  In this manner, the subtitle broadcast signal output from the H264 encoding apparatus 5 that performs the encoding process includes PTS information so that the video screen displayed on the monitor screen and the subtitle can be supported by the one-segment receiver 7. In addition, the one-seg receiver 7 refers to this PTS information in accordance with the PCR (Program Clock Reference) for timing processing, and performs decoding when the PTS added to the video (and audio) and the subtitle information matches. The recorded video and subtitle information are displayed together on the monitor screen.

  Conventionally, there is a method for preventing overwriting of subtitle data by reducing the delay time difference between the subtitle data and the video signal by correcting the subtitle data PES (Packetized Elementary Stream) minimum transmission interval to 1 second. It has been.

  However, in this method, the delay time is fixed regardless of the number of characters of the caption data. On the other hand, since subtitle information can only transmit character information for a maximum of two packets per second, if the number of characters increases, it takes time to transmit subtitles, so the receiver 7 effectively has a delay time difference from the video signal. For example, the delay time difference is almost eliminated when the number of packets becomes three, which is the prescribed maximum number.

As a result, with the conventional method of giving a fixed 1 second, a delay time of 1 second is added to the standby time, so that the subtitle update timing is displayed with a delay after the video display timing on the monitor. There was a problem that subtitles and video display were unnatural.
JP 2004-140504 A (page 31, FIG. 6)

  In one-seg broadcasting, in order to match conventional subtitles and video, the subtitle update timing is synchronized with the video depending on the number of subtitle data on the screen displayed on the receiver side, by giving subtitle data a fixed delay of 1 second for transmission. There was an unnatural problem.

  The present invention has been made to solve the above-described problem, and is capable of updating a caption transmission device and a caption transmission method for one-segment broadcasting, which are updated at the same time when video and caption display are aligned without being affected by the number of caption data. The purpose is to provide.

In order to achieve the above object, a caption transmission device according to the present invention provides a video signal output from a caption extraction means for separating and outputting a caption broadcast signal of an input terrestrial digital broadcasting system into video data and caption data. And subtitle data superimposed by the subtitle superimposing means, and transmitted as a one-segment subtitle broadcast signal, the subtitle broadcast signal of the input digital terrestrial broadcast system is separated into video data and subtitle data and output Extracting means, buffer means for temporarily outputting the separated subtitle data to be input, and outputting after the elapse of the time specified by the control signal, and counting the number of subtitle data packets input to the buffer means Packet size determination means for outputting the received packet number and the number of packets output after counting, and when the received packet number is 1, the subtitle The control signal is output to the buffer means so that the caption data is superimposed and output from the caption superimposing means after 1 second from the timing when the caption broadcast signal is input to the output means, and the number of received packets is In the case of 2, the control signal is sent to the buffer means so that the caption data is superimposed and output from the caption superimposing means after 0.5 seconds from the timing when the caption broadcast signal is input to the caption extracting means. When the number of received packets is 3, so that the caption data is superimposed and output from the caption superimposing means after 0.1 second from the timing when the caption broadcast signal is input to the caption extracting means. Control means for outputting the control signal to the buffer means; and the subtitle data in the video signal input from the subtitle extraction means. Superimposed at the timing when the subtitle data from the stage are input, characterized in that it comprises a closed caption superposition means for sending the one-segment subtitle broadcast signal.

Also, the subtitle transmission method of the subtitle transmission apparatus for terrestrial one-segment subtitle broadcasting of the present invention includes subtitle extraction means for separating and outputting the subtitle broadcast signal of the input terrestrial digital broadcast system into video data and subtitle data. A subtitle transmitting method of a subtitle transmitting apparatus, comprising a buffer means, a packet size determining means, a control means, and a subtitle superimposing means, superimposing the video signal and the subtitle data, and transmitting the subtitle data as a one-segment subtitle broadcast signal; The subtitle extraction means separates and outputs the subtitle broadcast signal of the input digital terrestrial broadcasting system into video data and subtitle data, and the buffer means receives the separated subtitle data and temporarily outputs it. After the accumulation, the packet size determination unit outputs the subtitle data input to the buffer unit after the time specified by the control signal has elapsed. The number of packets is counted and output, and the control unit receives the number of packets output by counting, and when the number of received packets is 1, the timing when the caption broadcast signal is input to the caption extraction unit When the control signal is output to the buffer means so that the subtitle data is superposed and output from the subtitle superimposing means after one second has elapsed and the number of received packets is 2, When the control signal is output to the buffer means so that the caption data is output after being superimposed from the caption superimposing means after 0.5 seconds have elapsed from the signal input timing, and the number of received packets is 3, The caption data is superimposed and output from the caption superimposing means after 0.1 seconds from the timing when the caption broadcast signal is input to the caption extracting means. The control signal is output to a buffer unit, and the subtitle superimposing unit superimposes the subtitle data on the video signal input from the subtitle extracting unit at a timing when the subtitle data is input from the buffer unit. It is characterized by being transmitted as a broadcast signal.

  According to the present invention, it is possible to provide a subtitle transmission apparatus and subtitle transmission method for one-segment broadcasting that are updated at the timing when video and subtitle display are aligned without being affected by the number of subtitle data.

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

FIG. 1 is a system diagram showing a configuration of a one-segment subtitle broadcasting system using a one-segment subtitle transmission apparatus according to an embodiment of the present invention.
In FIG. 1, a case where a one-segment broadcasting system is provided alongside a terrestrial HD broadcasting system and performs simulcasting will be described. As equipment on the transmission side, the master device 1, the VANC caption device 2, the one-segment caption transmission device 3 of the present invention, the down converter (hereinafter referred to as D / C) 4, the H264 encoding device (hereinafter referred to as H264ENC). 5. A transmission facility 6 and a one-seg receiver 7 are provided as receiving-side equipment, and an HD broadcast HD encoder H5, a transmission facility H6, and a receiver H7 are provided as an HD broadcast system.

  Here, the operation will be described by way of example in the case of creating a one-segment broadcast radio wave from the HD subtitle broadcast signal, but in the case of creating a one-segment broadcast radio wave from the SD subtitle or analog subtitle broadcast signal. The basic operations related to its creation are the same.

  In addition, there is a local clock 8 as a time information reference device for each device of the master device 1 to the transmission facility 6 to operate at a common timing, and time information is transmitted to each device via a network not shown in the figure, or The calibration is performed at a predetermined time with an internal clock (not shown) of each device.

  The one-seg broadcasting system of FIG. 1 is basically the same operation as the one-seg broadcasting system shown in FIG. 7 except that the one-seg subtitle sending device 3 whose operation is different from that of the one-seg subtitle sending device 300 shown in FIG. 7 is used. I do. Hereinafter, description of items common to FIG. 7 will be omitted, and an outline of a processing method of caption data in the one-segment broadcasting system according to the embodiment of the present invention will be described.

FIG. 2 is a functional block diagram for explaining the operation of the one-segment receiver 7.
In FIG. 2, a one-segment receiver 7 includes an RF processing unit 71, a detection demodulation unit 72, a reception buffer unit 73, an output unit 74, a monitoring control unit 75, and an input setting unit, which are connected to each other by an internal bus or the like. 76, and outputs received broadcast radio waves to a monitor (display) or a speaker.

  The RF processing unit 71 amplifies a broadcast radio wave received from an antenna (not shown), converts it to an intermediate frequency, and outputs it to the detection demodulation unit 72. The detection demodulator 72 detects and demodulates the input intermediate frequency signal of the broadcast radio wave into a baseband broadcast signal, converts it into subtitle data, a video signal packet, and an audio signal packet, for example, via the internal bus. To 73.

  Packets output therefrom are one-segment broadcasting data packets according to the ARIB regulations, and the reception buffer unit 73 buffers these packets in the caption buffer 731, the video buffer 732, and the audio buffer 733.

  The output unit 74 includes an H264 decoding output interface, and the video output unit 741 and the audio output unit 742 display the subtitles and the video on the monitor and the speaker, respectively, according to the control of the control monitoring unit 75. Screen information and audio signals are output.

  The monitoring control unit 75 monitors and interprets each operation and setting of the input processing unit 75 in which conditions such as the RF processing unit 71 to the reception buffer unit 73 and the reception channel are set via the internal bus. Then, for example, control is performed to adjust the timing of the corresponding caption data and the video packet from the caption buffer 731 and the video buffer 732 and output to the output unit 74 so that the video and the caption are displayed on the monitor in synchronization. To enable viewing of the required reception channel.

  Now, it is assumed that a continuous screen (video), audio, and subtitles displayed on the background of these scene videos (for example, displayed over two pages) constituting one scene (for example, A scene). The operation timing adjustment of the display process will be briefly described.

  Now, in the A scene, the background screens (A1, A2) of the first and second pages are displayed. Therefore, the video signal (multiple frames) as the background of the first page and the second page, the audio signal, and the caption data In short, as the above-described PTS, identification information of A1 and A2 is given to the broadcast signal output from the master device 1, respectively. The VANC caption device 2 and the one-segment caption transmission device 3 also perform packet transmission processing so that they correspond.

  Each signal and subtitle data received by the one-segment receiver 7 is input and stored in each of the buffers 731 to 733. The identification information of the PTS of the packet input to each buffer is compared and compared, and the above A1 , A2 may coincide with and correspond to the PTS of the packet in order to output a scene screen reproduced in order.

  Since the video signal packet is data transmitted in the fastest repetition cycle, the one-segment receiver 7 also uses this video signal packet as the PCR (synchronization information). In other words, the PTS of the video signal is also used as the PCR synchronization timing.

  In order to display the caption information in synchronization with the video, for example, caption data to which identification information A1 is added from the received and detected demodulated signal (for example, PTS-CA1 is assigned as identification information). Are stored in the caption buffer 731 prior to the input of the video signal.

  Subsequently, the monitoring control unit 75 monitors the PTS of the input video signal. When a video signal packet to which PTS-VA1 is added as identification information is input to the video buffer 732, the video signal and the subtitle are immediately displayed. Control is performed so that the data is extracted from both the buffers 731 and 732 and the audio buffer 733 and output from the output unit 74. Then, video, audio, and subtitles whose identification information is unified as “A1” are output and displayed correspondingly.

  Now, returning to FIG. 1, an outline of a procedure for performing normal one-segment broadcasting will be described.

  In the caption multiplex broadcasting, the VANC caption device 2 creates an HD caption broadcast signal in which caption data is superimposed on the HD video signal. At this point, the PTS described in “Subtitle Data Packet Arrangement and Internal Configuration” is added to the ARIB STD-B 37 so that the video and the subtitle correspond to each other. The HD subtitle broadcast signal is input to the one-segment subtitle transmission device 3 in order to superimpose the subtitles of the one-segment broadcast.

FIG. 3 is a functional block diagram for explaining the operation of the one-segment subtitle transmission apparatus 3.
In FIG. 3, the one-segment subtitle transmission device 3 includes an interface unit 31 for inputting / outputting subtitle broadcast data and a conversion unit 32 for converting HD subtitle data into subtitle data of one-segment broadcast.

  The interface unit 31 includes a control unit 311, a VANC subtitle extraction unit 312, and a VANC subtitle superimposition unit 313, and the conversion unit 32 includes a conversion table 321, an HD-one-segment subtitle data conversion unit 322, a size determination unit 323, and an output buffer 324. These components are connected to each other by an internal bus or the like. The detailed configurations described above are not limited to the above-described sections, and may be appropriately disposed inside the interface unit 31 and the conversion unit 32.

  The VANC caption extraction unit 311 extracts caption data (here, HD caption data) from the HD caption broadcast signal input from the VANC caption device 2, and outputs the caption data to the HD-one-segment caption data conversion unit 322 via the internal bus. Further, the video signal is output to the VANC caption superimposing unit 313. If the input HD caption broadcast signal is an analog signal, digital conversion means (not shown) is provided, the input signal is digitally converted, and the converted digital data is processed in the same manner. There may be.

  In the following description, the control unit 311 that monitors the internal bus reads the PTS of each signal and caption data input from the VANC caption device 2, and performs signal processing so that each signal and caption data corresponds.

  The HD-one seg subtitle data conversion unit 322 converts the input HD subtitle data into one seg subtitle data with a small number of subtitle data by referring to the conversion table 321 in which a method for converting to one seg subtitle data is set and stored. And output to the buffer unit 324.

  The size determination unit 323 counts the data size of the converted one-segment subtitle data, obtains the number of ARIB-specified packets according to the subtitle data size, and notifies the control unit 311 via the internal bus. The control unit 311 extracts the one-segment subtitle data from the output buffer 324 according to the number of packets, and inputs it to the VANC subtitle superimposing unit 313. The VANC subtitle superimposing unit 313 generates various VANC subtitle broadcast signals obtained by further adding one-segment subtitle data to HD, SD, and analog subtitle data to the video signal input from the VANC subtitle extraction unit. Then, the one-segment broadcasting VANC caption signal on which the one-segment caption data is superimposed is output to the H246 encoding apparatus 5 via the D / C 4. In the following description, one-segment subtitle data is abbreviated as subtitle data unless otherwise specified.

  Conventionally, the control unit 311 in FIG. 3 delays the output timing of subtitle data of the VANC subtitle broadcast signal output from the VANC subtitle superimposing unit 313 by 1 second, and outputs the subtitle data from the VANC subtitle superimposing unit 313. Was prevented from being overwritten.

4 and 5 are explanatory diagrams showing subtitle and video display timing (no subtitle data delay is present) in the one-segment receiver 7. FIG.
In FIG. 4 and FIG. 5, an example will be described in which caption data of one packet size is updated at intervals of 1500 ms. (A) and (b) of FIG. 4 and FIG. 5 are the input and output timing of caption data to the one-segment caption transmission device 300 in FIG. 7, respectively.

  4 and 5 (c) shows the timing of input to H264ENC5 via D / C4, and FIGS. 4 and 5 (d) show the encoding in H264ENC5 and the one-segment reception after passing through the transmission facility 6. The timing until the caption data is buffered by the device 7 is shown.

  In FIG. 4, subtitle data x (PTS-c1) of page N-1 is subtitled to H264ENC5 via D / C at timing t1 after processing time 100 msec from timing t0 input to the one-segment subtitle transmission apparatus 3. Is output. Similarly, in D / C4, the caption data x (PTS-c1) is input to H264ENC5 at timing t2 after a processing time of 200 msec.

  Then, broadcast radio waves that are H264 encoded and transmitted through the transmission facility 6 are received by the one-segment receiver 7. As a result, the caption data y (PTS-c1) is decoded at a timing t3 400 msec after the timing t0, and enters a state of waiting in the caption buffer 732.

  On the other hand, it takes 2100 msec from the time when the video signal n-1 (PTS-V1) is input to the one-segment subtitle transmission apparatus 3 to the timing tp when it is decoded by the one-segment receiver 7 and input to the video buffer 732.

  By the way, the N page subtitle data y (PTS-c2) is also input to the one-segment subtitle transmission apparatus 300 at the timing when 1500 msec has elapsed after the output of the N-1 page subtitle data x (PTS-c1). In each device, the signal is output or input at timing tn0 to timing tn3 and input to the subtitle buffer of the one-segment receiver 7 to 732.

  As can be seen from FIG. 4, N-1 page video n-1 (PTS-V1) is displayed, in other words, at the timing tp when the video signal is input to the video buffer 732, the N- One page of caption data x (PTS-V1) is overwritten by N pages of caption data y (PTS-c2) input to the caption buffer 731 at timing tn3 200 msec before timing tp. The input video signal and the PTS identification information number of the caption data are different from “1” and “2”.

  FIG. 5 shows a processing procedure for outputting after adding a delay time of 1 second (1000 msec) to the time taken to convert the subtitle data input to the conventional one-segment subtitle transmission apparatus 300 to improve this problem. . In this case, the one-segment subtitle transmission apparatus 300 in FIG. 7 generates the one-segment subtitle data and outputs it at the timing t2d (after 1200 msec from the timing t0) for 1 second, for example, after being retained in the subtitle buffer 731.

  As a result, N-1 page subtitle data X (PTS-C1) input from the one-segment subtitle transmission apparatus 300 to the H264 encoding apparatus via D / C4 is 1400 msec at timing t3d after the one-segment subtitle transmission apparatus 300 is input. After that, it is output. Then, the video signal n-1 (PTS-V1) of page N-1 waits at 731 in the subtitle buffer of the one-segment receiver 7 with a margin of 700 msec until the timing tp when the video signal n-1 (PTS-V1) is input to the video buffer 732.

  On the other hand, the caption data Y (PTS-C2) of the Nth page is restored to a caption signal by the one-segment receiver 7 at a timing tn3d after 2900 msec from the timing t0. The subtitle data X (PTS-C1) on page N-1 is not overwritten before -V1) is displayed.

  When the caption data is one packet, the display timing of the caption and the video is matched by adding the delay time of 1000 msec. However, in radio wave propagation of one-segment broadcasting, subtitle data has a maximum transmission rate between the transmission facility 6 and the one-seg receiver 7 of 2 packets per second. Further, the signal is input to the one-segment receiver with a delay of one second.

  In this case, overwriting of subtitle data does not occur, but even if the video changes, the subtitle for the previous video screen is still displayed, and there is a problem that subtitle display is unnatural in the conventional improvement means.

  Returning now to FIG. In the one-segment subtitle transmission apparatus 3 according to the embodiment of the present invention, the number of subtitle packets of the converted one-segment subtitle data is counted, and no delay is given in the case of 3 packets (or more), and a delay is given in the case of 1 packet. Like that. That is, by changing the delay time in accordance with the number of packets, a sense of incongruity does not occur in the alignment between subtitles and video.

FIG. 6 is a flowchart for explaining the processing procedure of the subtitle transmission timing of the one-segment subtitle transmission apparatus 5 in the embodiment of the present invention.
Hereinafter, a processing procedure of subtitle transmission timing will be described with reference to FIGS. In FIG. 3, the caption data input from the VANC caption device 2 is temporarily stored in the output buffer 324 as described above, the packet size is determined by the size determination unit 323, and the control unit 311 is informed via the internal bus. The number of subtitle data packets is input (step s1 in FIG. 6).

  When the number of packets is 1 (step s2 in FIG. 6 is 1), the control unit 311 inputs the subtitle data packet to the VANC subtitle extraction unit 312. The output is controlled after adjusting the residence time in the output buffer 324 so that the output is delayed for a second (1000 msec) (step s3).

  Further, when the number of packets is 2 (step s2 in FIG. 6 is 2), the delay time is corrected by subtracting the time required for the broadcast radio wave to transmit the subtitle 2 packet. For example, 0.5 seconds is the delay time. Then, the output is controlled after adjusting the residence time in the output buffer 324 (step s4).

  If the number of packets is the maximum allowable number of 3 packets (step s2 in FIG. 6 is 3) as described above, the broadcast wave of the caption data is demodulated by the one-segment receiver 7 and accumulated in the output buffer 324. Sufficient time is consumed to prevent overwriting. Therefore, the control unit 311 outputs the output after adjusting the residence time in the output buffer 324 so that the delay time is not given or the delay time is 0.1 seconds, for example, as the minimum adjustment time (or processing time). Control is performed (step s5).

  In this way, the one-seg receiver 7 can be displayed at the timing when the video and the subtitle are aligned regardless of the number of subtitle data packets without any changes.

  In the above description, the subtitle transmission method for one-segment broadcasting has been described by taking HD broadcasting as an example, but the same applies to SD broadcasting and analog broadcasting. In that case, the HD in the broadcast type and device name may be read as SD and analog, respectively.

  In the above description, the method of transmitting captions in one-segment broadcasting in simulcasting using terrestrial broadcast signals is described as an example. However, subtitle broadcasting is performed using video signals dedicated to one-segment broadcasting and caption data as transmission content. Similarly, when performing, the delay time of the caption data may be adjusted between the video signal and the caption data. In this case, the one-segment subtitle transmission device 3 in FIG. 3 receives the video signal and the subtitle data directly instead of the VANC subtitle device 2, bypasses the subtitle extraction unit 312 of the subtitle transmission device 3, and the VANC subtitle superposition unit 313. A video signal is input. The caption data may be directly input to the size determination unit 323 and the output buffer 324, bypassing the HD-one-segment caption data conversion unit 322.

1 is a system diagram showing a configuration of a one-segment subtitle broadcasting system according to an embodiment of the present invention. The block diagram explaining the function structure of a one-segment receiver. The functional block diagram explaining the function of the one-segment subtitle transmission apparatus concerning the Example of this invention. Explanatory drawing of the subtitle and video display timing (no subtitle data delay) in the one-segment receiver. Explanatory drawing of the subtitle and video display timing (with subtitle data delay) in a one-segment receiver. The flowchart explaining the process sequence of the subtitle transmission timing of the one-segment subtitle transmission apparatus in the Example of this invention. The system diagram which shows the structure of the conventional one-segment subtitle broadcasting system. The figure which shows the example in which a caption and a video | video are correctly matched and displayed. The figure which shows the example displayed without a subtitle | symbol and an image | video correctly matching.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Master apparatus 2 VANC subtitle apparatus 3, 300 One segment subtitle transmission apparatus 31 Interface section 311 Control section 312 VANC subtitle extraction section 313 VANC subtitle superimposition section 32 Conversion section 321 Conversion table 322 HD-one segment subtitle data conversion section 323 Size determination section 324 Output Buffer 4 Down converter (D / C)
5 H264 encoder (H264ENC)
6 Transmission equipment 7 One-segment receiver H5 HD encoder H6 Transmission equipment H7 Receiver H7

Claims (4)

The subtitle superimposing means superimposes the video signal output from the subtitle extracting means for outputting the subtitle broadcast signal of the input digital terrestrial broadcasting system into the video data and the subtitle data, and the subtitle data. In the subtitle sending device that sends out as
Subtitle extraction means for separating and outputting the subtitle broadcast signal of the input terrestrial digital broadcasting system into video data and subtitle data;
Buffer means for temporarily storing the input subtitle data to be input, and outputting after the time specified by the control signal;
A packet size determining means for counting and outputting the number of subtitle data packets input to the buffer means;
Receiving the number of packets output by counting,
When the number of received packets is 1, the subtitle superimposing unit outputs the superimposed subtitle data to the buffer unit after 1 second from the timing when the subtitle broadcast signal is input to the subtitle extracting unit. Output a control signal,
When the number of received packets is 2, the buffer means so that the caption data is superimposed and output from the caption superimposing means after 0.5 seconds from the timing when the caption broadcast signal is input to the caption extracting means. Output the control signal to
When the number of received packets is 3, the buffer means so that the caption data is superimposed and output from the caption superimposing means after 0.1 seconds have elapsed from the timing when the caption broadcast signal is input to the caption extracting means. Output the control signal to
Control means;
Subtitle superimposing means for superimposing the subtitle data on the video signal input from the subtitle extracting means at a timing when the subtitle data is input from the buffer means, and transmitting the subtitle data as a one-segment subtitle broadcast signal;
A caption transmission device comprising: In a caption transmission device for terrestrial one-segment caption broadcasting in which a caption superimposing means superimposes a video signal and caption data and transmits it as a one-segment caption broadcast signal,
  Buffer means for temporarily storing the input subtitle data and then outputting after the time specified by the control signal;
  A packet size determining means for counting and outputting the number of packets of the temporarily stored caption data;
  Receiving the number of packets output by counting,
    When the number of received packets is 1, the control signal is sent to the buffer means so that the caption data is superimposed and output from the caption superimposing means after one second from the timing when the caption data is input to the buffer means. Output
  When the number of received packets is 2, the subtitle data is superimposed and output from the subtitle superimposing means to the buffer means after 0.5 seconds from the timing when the subtitle data is input to the buffer means. Output a control signal,
When the number of received packets is 3, the subtitle data is superimposed and output from the subtitle superimposing means to the buffer means after 0.1 second from the timing when the subtitle data is input to the buffer means. Output control signal
Control means;
  Subtitle superimposing means for superimposing the subtitle data on a video signal at a timing when the subtitle data is input from the buffer means and transmitting the subtitle data as a one-segment subtitle broadcast signal;
A caption transmission device comprising: Subtitle extraction means for separating the subtitle broadcast signal of the input digital terrestrial broadcasting system into video data and subtitle data and outputting the data, buffer means, packet size determination means, control means, and subtitle superposition means In the subtitle transmission method of a subtitle transmission apparatus that superimposes the video signal and the subtitle data and transmits the one-segment subtitle broadcast signal,
  The caption extraction means separates and outputs the caption broadcast signal of the input digital terrestrial broadcasting system into video data and caption data,
  The buffer means receives the separated subtitle data, temporarily stores it, and then outputs it after elapse of the time specified by the control signal,
  The packet size determination means counts and outputs the number of subtitle data packets input to the buffer means,
  The control means includes
Receiving the number of packets output by counting,
    When the number of received packets is 1, the subtitle superimposing unit outputs the superimposed subtitle data to the buffer unit after 1 second from the timing when the subtitle broadcast signal is input to the subtitle extracting unit. Output a control signal,
  When the number of received packets is 2, the subtitle superimposing means outputs the superimposed data to the buffer means after 0.5 seconds from the timing when the subtitle broadcast signal is input to the subtitle extracting means. Outputting the control signal;
  When the number of received packets is 3, the subtitle superimposing means outputs the superimposed subtitle data to the buffer means after 0.1 seconds from the timing when the subtitle broadcast signal is input to the subtitle extracting means. Outputting the control signal;
  The subtitle superimposing unit superimposes the subtitle data on the video signal input from the subtitle extracting unit at a timing when the subtitle data is input from the buffer unit, and transmits the subtitle data as a one-segment subtitle broadcast signal. A subtitle transmission method of a subtitle transmission apparatus. In a caption sending method of a caption sending device comprising a buffer means, a packet size determining means, a control means, and a caption superimposing means, superimposing a video signal and caption data and sending it as a one-segment caption broadcast signal,
  The buffer means receives the subtitle data, temporarily stores it, and outputs it after elapse of the time specified by the control signal,
  The packet size determination means counts and outputs the number of subtitle data packets input to the buffer means,
  The control means includes
Receiving the number of packets output by counting,
    When the number of received packets is 1, the control signal is sent to the buffer means so that the caption data is superimposed and output from the caption superimposing means after one second from the timing when the caption data is input to the buffer means. Output
  When the number of received packets is 2, the subtitle data is superimposed and output from the subtitle superimposing means to the buffer means after 0.5 seconds from the timing when the subtitle data is input to the buffer means. Output a control signal,
  When the number of received packets is 3, the subtitle data is superimposed and output from the subtitle superimposing means to the buffer means after 0.1 second from the timing when the subtitle data is input to the buffer means. Output a control signal,
  A subtitle transmitting method of a subtitle transmitting apparatus, wherein the subtitle superimposing unit superimposes the subtitle data on the video signal at a timing when the subtitle data is input from the buffer unit, and transmits the subtitle data as a one-segment subtitle broadcast signal.

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