JP4074504B2 - Receiver - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a broadcast number of a digital broadcast using a time interleave process.PairReceiving device to receiveIn placeRelated. In particular, the broadcast number of Japanese terrestrial digital broadcasting (ISDB-T: Integrated Service Digital Broadcast-Terrestrial)PairReceiving device to receiveIn placeRelated.
[0002]
[Prior art]
  Conventionally, as an example of digital broadcasting aimed at improving the reception state of mobile reception, there is one using a broadcast program providing method shown in the spectrum diagram of FIG. 10 (see, for example, Patent Document 1). In FIG. 10, the horizontal axis 401 represents frequency, the vertical axis 402 represents broadcast power, and the broadcast signal 403 of the digital broadcast is displayed. As shown in FIG. 10, this digital broadcast is formed by a digital terrestrial broadcast signal 403 obtained by collecting a plurality of OFDM (Orthogonal Frequency Division Multiplexing) segments composed of a plurality of digitally modulated carriers. The OFDM segment is indicated by adjacent rectangles 406, 407, 408 to 409, etc. in the figure.
[0003]
  Here, the “OFDM segment” refers to a plurality of carriers forming an OFDM broadcast wave, for example, in the case of digital terrestrial broadcasting, adjacent carrier waves in the entire broadcast wave of 1405 to 5617 carriers. Means a group. For example, in terrestrial digital broadcasting, one broadcast wave is divided into 13 segments, and data redundancy for error correction, various interleaving processes, and the like can be performed separately for each segment (actual In addition, processing is performed for three groups in which segments are further collected).
[0004]
  In the broadcast signal 403, when a plurality of OFDM segments are collected to form the broadcast signal 403, the power of at least one specific segment of each OFDM segment is set to be different from the other segments.
[0005]
  In other words, by performing broadcasting for mobile reception using only a specific segment (405 or 406) whose broadcast power is higher than that of the other segments described above, the reception intensity in mobile reception is increased and reception while moving Even in Japan, a broadcast providing method that does not easily cause a reception failure is possible.
[0006]
  Hereinafter, broadcasting performed using only a specific segment as described above is referred to as “broadcast by a partial reception segment”. In particular, a broadcast intended to receive and view only one segment of the partial reception segments is hereinafter referred to as “one segment broadcast”. In the Japanese terrestrial digital broadcasting, the broadcast wave of the one-segment broadcast is arranged at the center of the segment of the entire broadcast wave (position of segment 405 in FIG. 10).
[0007]
[Patent Document 1]
          JP 2000-101542 A
[0008]
[Problems to be solved by the invention]
  However, in the broadcast program providing method described above, the configuration of the transmission / reception apparatus becomes complicated, so it is not adopted as a standard for terrestrial digital broadcasting and cannot be used practically. In addition, in the one-segment broadcasting, which is particularly important for mobile reception of digital terrestrial broadcasting, the broadcast output power cannot be changed within the segment even in the broadcasting program providing method. When the situation deteriorates, the video, audio, and subtitles are disturbed almost simultaneously, causing a problem that the viewer cannot keep up with the progress of the program.
[0009]
  An object of the present invention is to provide a broadcast number that can replace the display of subtitles even when the reception situation temporarily deteriorates.PairReceiving device to receivePlaceIs to provide.
[0010]
  In particular, the digitization of terrestrial television broadcasting has a problem that there are few advantages due to digitization in spite of the large capital investment required to cope with the digitization on the broadcasting station side. Among them, an increase in reception opportunities while moving, that is, an increase in viewing time of viewers is one of the greatest advantages of digitization. This is because the viewing time has increased to almost the upper limit in daily life, so in order to increase the viewing time, new viewing such as watching while moving or waiting time at stations, stops, etc. This is because opportunities need to be increased. For this reason, the narrow band broadcast suitable for carrying around by the partial reception segment and particularly the one segment broadcast are particularly regarded as important.
[0011]
  For this reason, it is one of the very big issues to enable viewers to follow the progress of a broadcast program and continue interest in the broadcast program even when the reception state deteriorates during movement.
[0012]
[Means for Solving the Problems]
  To achieve the above objective,In the receiving apparatus of the present invention, the received subtitle data is received by the receiving means, which is a digital broadcast capable of data multiplex broadcasting, including a plurality of replaceable subtitle data broadcasted at time intervals. Is output by subtitle output means. Then, when there is a reception failure in some of the replaceable subtitle data, the subtitle replacement means outputs the subtitle output means output with another replaceable subtitle data different from the subtitle data in which the reception failure has occurred. The subtitle output means is controlled by the subtitle output start means so that the subtitle display by the subtitle data is started when a reception failure occurs in the video data or audio data. That is, when a reception failure occurs in video data or audio data, the receiving apparatus switches to a setting for displaying subtitles instead of a setting for displaying subtitles, and automatically starts displaying subtitles.
  That is, the broadcast including the caption data is received by the receiving unit, and the caption data is displayed on the display device as the caption, for example. At this time, the caption data in which the reception failure has occurred is replaced with another replaceable caption data that is broadcast at a time interval and output.
  According to the receiving apparatus having the above configuration, the reception intensity of the broadcast wave is temporarily weakened or the interference wave enters. Even if the error cannot be corrected by the error correction method of the broadcast standard, it is possible to perform subtitle output by substituting with another replaceable subtitle data broadcasted at the above time interval. The subtitles are displayed on the screen as long as there is no reception failure at all broadcast times of replaceable subtitles being broadcast.
  Therefore, even when the reception state deteriorates, the viewer does not overlook important information such as dialogue due to the progress of the program, and can provide continuous broadcasting to the viewer.
  In particular, replaceable subtitle data is broadcast at a time interval, so that the replacement of the data can be performed effectively. For example, the receiving apparatus uses a delay means such as a buffer to set the time interval. The data broadcasted with a gap is synchronized and output as a replacement.
  Even if video or audio output is lost, the subtitles are automatically displayed, so that information is not lost to the viewer as the program progresses.
  Further, the video data or audio data reception failure in this case includes not only the case where the video or audio is actually interrupted, but also the case where the frequency of error occurrence during demodulation and decoding increases. For example, a predetermined threshold value may be provided for the error occurrence frequency, and a reception failure may be determined when an error frequency exceeding the threshold value occurs. In particular, it is more preferable to display subtitles before video or audio is actually interrupted when the frequency of error occurrence during demodulation and decoding increases.
  Further, in the receiving apparatus according to an embodiment, when the reception failure of the video data or the audio data is recovered, the subtitle output unit stops the subtitle output so that the subtitle output started by the subtitle output start unit is stopped. Control by means. That is, when the reception failure is recovered after the video or audio reception failure, the subtitle display is automatically stopped.
  According to the receiving apparatus of the above embodiment, when the reception failure is recovered, the convenience is improved by automatically stopping the display of subtitles. In particular, in the case of mobile reception, the reception situation often changes repeatedly, and each time the user has to perform an operation to stop displaying subtitles. Therefore, this configuration is particularly suitable.
  Moreover, the automatic stop of the subtitle display may be stopped immediately after the reception failure is recovered or may be stopped after a certain period of time. However, in particular, it is more preferable to configure the subtitle display to stop when there is no reception failure for a certain period.
  Of this inventionReceive device receivesBroadcast program provision methodAsIn digital broadcasting capable of data multiplex broadcasting, time interleaving processing is performed by the digital broadcasting broadcasting method. Then, each of the replaceable subtitle data is broadcast at time intervals. At this time, a time interval between at least two pieces of subtitle data among the plurality of subtitle data that can be replaced is equal to or longer than a time length in which the plurality of subtitle data is spread on the time axis by the time interleaving process. And
[0013]
  In other words, each of the plurality of replaceable subtitle data has a time interval greater than the time length in which the data is spread on the time axis by the time interleave processing of the broadcasting system (hereinafter referred to as the time interleave length). It will be broadcast in the broadcast program.
[0014]
  According to the broadcast program providing method, even if the reception intensity of the broadcast radio wave is temporarily weakened or an interference wave is included, and the error cannot be completely corrected by the error correction method of the broadcast method, the time interval described above is used. It is possible to provide a broadcast program that can be replaced with another replaceable subtitle data that has been broadcasted and that can be output as a subtitle. In addition, since the time interval is equal to or longer than the time interleave length, the probability of replacement with the other subtitle data is improved.
[0015]
  The “subtitle data that can be replaced” in this case is subtitle data that is originally broadcast, and at least one subtitle data that has the same subtitle content as the subtitle data that is originally broadcast. Can be output instead of other caption data.
[0016]
  The above “subtitle content is the same” means that the viewer sees the same subtitle content, and control codes such as identification codes for data multiplexing may be different. Also, intentionally subtitles or part of them, for example, kanji, hiragana, katakana, etc., or change the font (cursive, line, gothic, italic, etc.) AlsoGood.
[0017]
  On the other hand, when broadcasting multiple subtitles originally for the purpose of viewing in different languages, such as Japanese, English, Chinese, other foreign languages, etc., that is, bilingual subtitles or multilingual It may be broadcast with word subtitles. In this case, even if a subtitle reception failure in a certain language is replaced by another language, it does not make sense for general viewers, and thus is not included in the present invention. Also, broadcast programs that viewers select and view one such as sports broadcasts such as explanatory subtitles broadcasted by one team side, even if reception trouble occurs in certain subtitle data Since it cannot be replaced with other caption data, it is not included in the present invention.
[0018]
  In addition, for example, in the case of subtitles for young people (for example, subtitles mainly composed of kana) and subtitles for adults (for example, subtitles mainly composed of kanji), subtitles for adult subtitles are replaced with subtitles for younger age. However, it is included in the present invention, but on the contrary, substituting reception for subtitles for young people with subtitles for adults does not make sense for younger people. Is less preferred.
[0019]
  Further, in this case, “broadcast each of a plurality of subtitle data with a time interval greater than or equal to the time interleave length” means, for example, a time during which each subtitle data is spread on the time axis by the time interleave processing described above. Is set such that the time interval between the medians between the plurality of caption data is equal to or greater than the time interleave length, and the plurality of caption data is transmitted.
[0020]
  Alternatively, for example, the difference between each caption data in the time difference between the presentation time accompanying each caption data and the broadcast time of the caption data is set to be equal to or greater than the time interleave length, This refers to sending closed caption data.
[0021]
  In other words, by setting each of the plurality of subtitle data that can be replaced to be broadcast with a time interval greater than or equal to the time interleave length, the range of spread in the time axis direction by time interleave processing of certain subtitle data is There is no overlap in the range of diffusion in the time axis direction by the time interleaving process of other subtitle data that can be replaced. As a result, even if the reception intensity of broadcast radio waves temporarily decreases and a failure occurs in the reception of certain subtitle data, other subtitle data that can be replaced that is broadcast with a time shifted by more than the time interleave length is used. It does not affect. Therefore, in the fixed number of subtitle data that can be replaced, the probability that the subtitle output can be replaced in the case of reception failure is greatly improved.
[0022]
  In addition, when there are three or more subtitle data that can be replaced, broadcasting with a time interval greater than or equal to the time interleave length between all the subtitle data allows more reliable output of reception failure. Is preferred because it can be substituted. However, any one of the plurality of replaceable subtitle data combinations may be broadcast with a time interval equal to or greater than the time interleave length, and all replaceable subtitle data is not necessarily temporally longer than the time interleave length. There is no need to broadcast at a long interval.
[0023]
  In addition, the “time interleaving process” described above is a process of actively diffusing data on the time axis in the broadcasting system, and mainly prevents broadcast interruption due to a temporary decrease in received power due to fading. That is the purpose. In addition to the time interleaving process described above, the data is spread by byte interleaving or bit interleaving, and part of the spreading has a spread on the time axis. There is.ThisThese time interleave lengths may include the width of diffusion in the time axis direction. However, for example, in the Japanese terrestrial digital broadcasting broadcasting system, the spreading width in the time axis direction is smaller than the spreading width by the time interleaving process, and can be substantially ignored.
[0024]
  Further, in the error correction in the broadcasting system using the time interleaving process, if a failure occurs in reception over the time interleave length, the error correction cannot be performed. On the other hand, PlaceWith the configuration in which each of a plurality of replaceable subtitle data is broadcast with a time interval equal to or greater than the time interleave length, subtitles can be replaced and output even in a longer reception failure.
[0025]
  In mobile reception, which greatly contributes to improving the viewing time of viewers, there are many opportunities for reception in the public place. Like mobile phones, voice output is restricted by restricting voice output in the manner of the user. Viewing with subtitles that have been converted (actually, no audio is output, but for the sake of convenience, the use of broadcasting is expressed as viewing for the sake of convenience) increases. Therefore, unless the convenience of viewing with subtitles is improved, the viewing time of the viewer cannot be significantly improved. If the subtitles are interrupted, as in the case of the audio, in some cases, it may be impossible to keep up with the progress of the program by overlooking the dialogue. Therefore, thisRelease ofThe transmission program providing method is particularly effective.
[0026]
  In addition, subtitle data has an extremely small amount of data compared to video and audio data, and therefore, even if a plurality of replaceable subtitle data is broadcast, the original broadcasting is not hindered. Therefore, in particular, the configuration in which a plurality of subtitle data that can replace subtitle data is not transmitted as a plurality of substitutable data that is not transmitted as audio or video data is as described above although the burden on both the broadcasting station and the receiving device is small. It is particularly preferable because it has a great effect of improving the audience rating.
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
  The time interleaving process described above is intended to compensate for data loss due to a temporary decrease in the reception intensity of broadcast radio waves due to fading as described above, and assumes a decrease in reception intensity for a short time. . However, when actually broadcasting, there were more than the chances that the reception could be interrupted due to multiple conditions that could easily cause a reception failure, or the reception position was completely in the shadow of a radio wave.
[0033]
  For example, when moving on a train or bus, the reception strength may decrease continuously due to fading due to the complicated layout of the building, or it may be shadowed by radio waves due to the shadow of a large building. And reception may be interrupted. In addition, reception may be interrupted due to the influence of passing vehicles or people while walking, at a station platform, or at a bus stop such as a bus stop.
[0034]
  However, as a result of examination in the above environment, it has been found that the above reception failure rarely lasts for more than 1 second. For this reason, each subtitle data that can be replaced is broadcast with an interval of 1 second or more.FruitThe embodiment is particularly effective.
[0035]
  Also,the aboveIn the broadcast program providing method, the data multiplex broadcast is broadcast by partial reception segments of a plurality of OFDM segments composed of a plurality of digitally modulated carriers.
[0036]
  In other words, a plurality of replaceable subtitle data is data-multiplexed together with other data (for example, video and audio data) and broadcast by partial reception segments of a plurality of OFDM segments composed of a plurality of digitally modulated carriers. Unlike other broadcasting methods, the OFDM modulation method has an advantage that narrow band broadcasting can be performed using part of the frequency band. For example, as in the above-described terrestrial digital broadcasting, there is a case where broadcasting is performed by a partial reception segment that broadcasts a program using a specific OFDM segment in a broadcast wave. In mobile reception, this partial reception segment is often used due to restrictions on portability of the receiving apparatus. However, in the case of broadcasting by the partial reception segment, particularly in the terrestrial digital broadcasting standard, data such as video, audio, and subtitles are broadcast with the same error correction method, for example, with the same redundancy and the same time interleave length. If a reception failure occurs during reception, all of them cannot be received in the same way, and the viewer may easily lose track of the program, which may cause a problem that the audience rating of the program does not increase.
[0037]
  UpReleaseAccording to the transmission program providing method, there is an effect of increasing the audience rating of the program by reducing the interruption of subtitles as described above.
[0038]
  In particular, in the partial reception segment broadcasting, since the receiving apparatus is downsized and the opportunity for mobile reception increases, the above problem is significant. In particular, in mobile reception, since there are many cases where a sufficient directional antenna is not used as a reception antenna, the influence of fading tends to be larger and more frequent. for that reason, EffectThe fruit is particularly large.
[0039]
  Also, subtitle data has a very small amount of data compared to video data and audio data. Therefore, even if each of a plurality of replaceable subtitle data is broadcast, the increase in the total data amount of the broadcast data is extremely small, and the partial reception segment Is particularly suitable for narrow-band broadcasting, especially for one-segment broadcasting.
[0040]
  Also,the aboveIn the broadcast program provision method,For example,A plurality of replaceable video data is broadcast with a time interval greater than a time length in which each of the plurality of video data is spread on the time axis by the time interleaving process. That is, like the replaceable subtitle data, each of the replaceable video data is broadcast with a time interval. At this time, a time interval between at least two pieces of video data among the plurality of replaceable video data is equal to or longer than a time length in which the plurality of video data are spread on the time axis by the time interleaving process. And
[0041]
  UpReleaseAccording to the transmission program providing method, it is possible to provide a broadcast program that not only includes subtitles but also reduces video interruptions and greatly increases the chance of viewing in the public place.
[0042]
  Of course, it is possible to broadcast not only subtitles and videos but also audio data that can be replaced in the same way. However, as described above, in order to increase the viewing time itself, the subtitles and videos that are used visually are used. It is more preferable to make the process uninterrupted first,Broadcast program provision methodIs particularly effective.
[0043]
  In this case, “a plurality of replaceable video data” refers to video data originally broadcast and different video data having the same video content as at least one or more video data originally broadcast. Can be output in place of another video data.
[0044]
  The above “same video content” means that the video content viewed by the viewer is the same, and control codes such as identification codes for multiplexing data may be different. Also, if you intentionally change the color tone or resolution of the video,Good. In addition, the replaceable video data may include data in which moving image frames are thinned out, and the frequency of thinning out may not be constant. Alternatively, video frames can be thinned out automatically, for example by thinning out at regular intervals, but there is also a method in which important scenes are selected in advance on the broadcasting station side and thinned out to leave the scenes. Is possible. By selecting an important scene in advance on the broadcast station side and thinning out the scene so that the scene is left, the viewer can be surely viewed the necessary scene, and the broadcast program can be improved.
[0045]
  In particular, in the broadcast by the partial reception segment, particularly in the one-segment broadcast, since the broadcast band is small, it is preferable to use the video data in which the image frames are thinned out as the replaceable video data.
[0046]
  On the other hand, when a plurality of videos are broadcasted and selected by a viewer, for example, in a plurality of video data in which a story of a drama is branched into a plurality and a viewer selects and views one of them, Even if a reception failure occurs in certain video data, it cannot be replaced with video data of another story, so it is not included in the present invention.
[0047]
  In addition, a broadcast program that viewers select and watch one of them, such as sports broadcasts broadcast separately on the side of one team, can be used even if reception failure occurs in certain video data. Therefore, it is not included in the present invention.
[0048]
[0049]
[0050]
[0051]
[0052]
[0053]
[0054]
[0055]
[0056]
[0057]
[0058]
[0059]
[0060]
[0061]
[0062]
[0063]
[0064]
[0065]
[0066]
  Also,Send digital broadcasts that allow data multiplex broadcastingTransmitterAsThe subtitle data is encoded by the subtitle encoding means. Then, the subtitle data encoded by the subtitle encoding means is delayed by the first delay means. Further, the subtitle encoding means encodes the subtitle data with a delay time shorter than the time length over which the subtitle data is spread on the time axis by the time interleaving process of the broadcasting system, than the delay time of the first delay means. The subtitle data is delayed by the second delay means. Then, a data stream creation means creates a data stream in which the encoded caption data from at least the first delay means and the second delay means is multiplexed. Then, the data stream is broadcast by a broadcasting means as a digital broadcast capable of data multiplex broadcasting.
[0067]
  That is, the caption data is first encoded. In order to perform broadcasting, it is necessary to use a data stream in which the amount of data per unit time in the entire broadcasting including the encoded caption data is matched to the broadcasting band. For this purpose, the encoded subtitle data is delayed by delay means to adjust the transmission to the data stream creating means. At this time, the delay time of the second delay means is made smaller than the delay time of the first delay means by a difference equal to or greater than the time interleave length. Note that the caption data encoded by the caption encoding means is a plurality of replaceable caption data, and the time interval between at least two of the caption data is determined by the first and second delay means. Try to be over the time interleave length.
[0068]
  According to the transmission apparatus configured as described above, it is possible to provide a broadcast program that broadcasts a plurality of replaceable subtitle data with a time interval equal to or greater than the time interleave length.
[0069]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, the present inventionReceiverWill be described in detail with reference to the illustrated embodiment.
[0070]
[First Embodiment]
  In the first embodiment of the present invention, in a broadcasting system based on Japanese terrestrial digital broadcasting (BST-OFDM: Band Segmented Transmission-Orthogonal Frequency Division Multiplexing) as an example of a digital broadcasting capable of data multiplex broadcasting., ReleaseA transmission program providing method, a transmitting apparatus for broadcasting the transmitting program, and a receiving apparatus for receiving the broadcast will be described. The above-mentioned Japanese terrestrial digital broadcasting employs a broadcasting method that performs time interleaving processing.
[0071]
  In addition, as an example of a broadcast by a partial reception segment of a plurality of OFDM segments composed of a plurality of digitally modulated carriers, a one-segment broadcast (broadcast intended to receive and view only one segment of the partial reception segments) ) Will be described.
[0072]
  Figure 1The second1 shows a block diagram of a transmission apparatus according to an embodiment. FIG. FIG. 2 is a block diagram of the receiving apparatus according to the first embodiment of the present invention.
[0073]
  First, the overall configuration will be described. FIG. 1 shows a configuration related to the present invention as an example of a transmission apparatus that transmits a digital broadcast capable of data multiplex broadcasting.
[0074]
  The transmission apparatus shown in FIG. 1 has an encoding unit 106 as an example of subtitle encoding means for encoding subtitle data, and a first delay that delays the subtitle data encoded by the encoding unit 106. As an example of the means, the delay buffer 112 and delay buffers 115 and 116 as examples of the second delay means for delaying the encoded caption data with a delay time shorter than the delay time of the delay buffer 112 by a time interleave length or more. have.
[0075]
  In addition, the transmission device receives the encoded caption data from the delay buffers 112, 115, and 116, and a system encoding multiplexing unit as an example of a data stream generating unit that generates a data stream obtained by multiplexing them 117.
[0076]
  In addition, the transmission apparatus includes a modulation unit 119 and a transmission unit 122 as an example of a broadcast unit that broadcasts a data stream.
[0077]
  FIG. 2 shows a configuration related to the present invention as an example of a receiving apparatus that receives the digital broadcast capable of data multiplex broadcasting.
[0078]
  The receiving apparatus shown in FIG. 2 includes a receiving unit 201, a demodulating unit 203, and a separation system decoding unit 205 as an example of a receiving unit that receives a broadcast including a plurality of replaceable subtitle data broadcast at time intervals. Have.
[0079]
  In addition, the reception apparatus includes a caption decoding unit 226, a video synthesis unit 223, and a display 224 as an example of a caption output unit that outputs the caption data.
[0080]
  In addition, when a reception failure occurs in some of the replaceable subtitle data, the receiving device uses the subtitle output means to replace the subtitle data different from the subtitle data in which the reception failure has occurred. A subtitle replacement unit 225 is provided as an example of subtitle replacement means for replacing output.
[0081]
  Next, a broadcast program providing method will be described with reference to FIG.
[0082]
  Broadcast program data is supplied from an audio data input unit 101, a video data input unit 102, and a caption data input unit 103, respectively.
[0083]
  In the audio encoding unit 104, the video encoding unit 105, and the video encoding unit 106, the input data from the data input units 101, 102, and 103 are encoded and primary packets 107, 108, 109 is sent to the delay buffers 110, 111, and 112, respectively.
[0084]
  For example, TV audio data and TV video data from the audio data input unit 101 and the video data input unit 102 are encoded by the encoding units 104 and 105 in MPEG-2 (Moving Picture Experts Group Phase 2) or The primary packets 107 and 108 are created by encoding for each video frame or each audio frame by an encoding method such as MPEG-4 (Moving Picture Experts Group Phase 4).
[0085]
  Here, since it is a one-segment broadcast, the MPEG-4 system is used for encoding video data, and the MPEG-2 system is used for encoding audio data.
[0086]
  Here, “video frame” means video data for one screen, and “audio frame” means audio waveform data for a predetermined time, and each frame unit constitutes one primary packet. Yes.
[0087]
  In addition, subtitle data from the subtitle data input unit 103 is a subtitle encoding unit 106 that collects subtitle data (hereinafter referred to as subtitle frames) to be displayed at one time and follows the broadcast standard format. The character code is converted and encoded together with the character font, display position designation data, etc., and the primary packet 109 is created.
[0088]
  At this time, using the time information from the system time clock (STC: System Time Clock) 113, a presentation time (PTS: Presentation Time Stamp) 114 required for synchronous reproduction in the receiving device is added to each primary packet. The In addition, in video data or the like, a decoding time (DTS: Decoding Time Stamp) indicating a time for further decoding may be added. In other words, the presentation time and the decoding time are examples of information indicating timing for presenting the video frame, the audio frame, and the caption frame to the viewer.
[0089]
  The above-described MPEG-2, MPEG-4, and subtitle data broadcast standard formats and conversion to primary packets are existing techniques of each broadcasting system, and detailed description thereof is omitted.
[0090]
  In the first embodiment, the primary packet 109 output from the caption encoding unit 106 is further duplicated to create another primary packet, which is sent to delay buffers 115 and 116 different from the delay buffer 112. Configured to do. That is, as an example of a plurality of subtitle data that can be replaced, a primary packet having the same subtitle data content is sent to a plurality of delay buffers 112, 115, and 116.
[0091]
  The system encoding and multiplexing unit 117 reads the primary packets of the delay buffers 110, 111, 112, 115, and 116, and distinguishes the difference between the primary packets, in this case, the difference between the buffers. Is converted again into a secondary packet (TSP: Transport Stream Packet) to which an identification code is added. Then, the secondary packets are multiplexed, and a transport stream (TS: Transport Stream) 118 in which the secondary packets are continuous is created and sent to the modulation unit 119.
[0092]
  In addition, although not shown, the system encoding and multiplexing unit 117 encodes other data information such as program arrangement information (SI: Service Information) and program specification information (PSI: Program Specific Information). Are similarly multiplexed.
[0093]
  In addition, a system time clock reference signal (PCR: Program Clock Reference) 120 for performing synchronous reproduction of each data at the time of reception is generated based on the time information from the system time clock 113, and similarly the system coding multiplexing is performed. Multiplexed by the unit 117.
[0094]
  At this time, each delay buffer smoothes fluctuations in the processing time of the encoding units 104, 105, and 106, and creates the transport stream 118 having a constant transmission rate from a primary packet with fluctuations in the data amount. Or buffering to prevent overflow and underflow due to inconsistencies in the amount of data. Therefore, microscopically, the delay time of the delay buffer varies to some extent depending on the processing. Thereafter, the delay time of the delay buffer is a value averaged to such an extent that microscopic fluctuations in the delay time can be ignored.
[0095]
  In the first embodiment, as an example of a method of broadcasting each of the plurality of replaceable subtitle data with a time interval longer than the time interleave length, a delay of the delay buffer 116 is used. The time is shorter than the delay time of the delay buffer 115, the delay time of the delay buffer 115 is shorter than the delay time of the delay buffer 112, and the difference between the delay times of the delay buffers is made twice the time interleave length. It is configured.
[0096]
  By making the difference between the delay times of the delay buffers twice the time interleave length, it is possible to more reliably prevent the influence of a decrease in reception strength due to one fading from affecting another replaceable voice data. be able to.
[0097]
  The modulation unit 119 modulates the transport stream 118 created by the system encoding and multiplexing unit 117 to create a baseband signal (or intermediate frequency signal) 121 and send it to the transmission unit 122.
[0098]
  In the transmission apparatus of the first embodiment, a terrestrial digital broadcast transmission method is used, and the modulation unit 119 performs redundancy processing for error correction, energy spreading processing, time interleaving processing, interleaving processing such as frequency interleaving processing, and the like. Thereafter, a baseband signal (or intermediate frequency signal) is created by performing discrete inverse Fourier transform, digital analog conversion, or the like.
[0099]
  The transmission unit 122 converts the baseband signal (or intermediate frequency signal) 121 into a high-frequency signal through a frequency converter, a filter, an amplifier, etc., and broadcasts it as a broadcast radio wave from the antenna.
[0100]
  The generation method of the secondary packet in the system encoding and multiplexing unit 117 and the configuration of the modulation unit 119 and the transmission unit 122 are existing techniques and will not be described in detail.
[0101]
  According to the transmitting apparatus of the first embodiment, since the difference between the delay times of the delay buffers 112, 115, and 116 is greater than or equal to the time interleave length, a plurality of subtitle data that can replace each subtitle data. As described above, it is possible to provide a broadcast program that is broadcast with a time interval longer than the time interleave length.
[0102]
  Also, according to the broadcast program providing method, each of a plurality of subtitle data that can be replaced is broadcast with a time interval equal to or longer than the time interleave length of the broadcast system. Spreading does not overlap in time between the plurality of replaceable subtitle data. Therefore, even when the error cannot be corrected by the error correction of the broadcasting system, it is highly likely that another replaceable subtitle data among the replaceable subtitle data can be normally received. It is possible to provide a broadcast program that can continue to display subtitles even when errors cannot be corrected.
[0103]
  In the broadcast program providing method, the broadcast station can easily adjust the number of subtitle data broadcasts that can be replaced and the time interval of each broadcast time to be broadcast a plurality of times according to the usage situation of the viewer. Has the advantage of being possible. In particular, there is a special advantage that can be changed without changing the broadcasting standard.
[0104]
  In the first embodiment, the primary packet 109 output from the encoding unit 106 is duplicated to generate another replaceable subtitle data primary packet for the delay buffer 112. Although it is configured to send the data to the delay buffers 115 and 116, the data packetized using the encoding unit different from the encoding unit 106 using the subtitle data from the subtitle data input unit 103 is used. It may be configured so that it is created and sent to the delay buffers 115 and 116.
[0105]
  When the encoding unit is different as described above, it is preferable that the presentation time to be added is the same for the subtitle data having the same content between the subtitle data that can be replaced. It can also be configured such that the broadcast is shifted by the offset amount, and the reception side takes into account only the offset amount.
[0106]
  Next, with reference to FIG. 2, a description will be given of the processing flow of the receiving apparatus that receives the broadcast program.
[0107]
  First, in the receiving unit 201, a broadcast radio wave is received by an antenna and converted into a baseband signal (or intermediate frequency signal) 202 of a broadcast program of a selected broadcast station through a tuner, an amplifier, a filter, a frequency converter, and the like.
[0108]
  The demodulator 203 demodulates the baseband signal (or intermediate frequency signal) 202 to reproduce a transport stream (TS) 204 in which secondary packets (TSP) are continuous.
[0109]
  In the first embodiment, the demodulating unit 203 performs analog-to-digital conversion, discrete Fourier transform, deinterleave processing, and error correction processing on the baseband signal (or intermediate frequency signal) 202 as a terrestrial digital broadcast receiving device. And demodulate the secondary packet.
[0110]
  In this process, error correction is performed in units of secondary packets using the redundant code created by the modulation unit 119 of the transmission apparatus shown in FIG. Therefore, the secondary packet whose error cannot be corrected is lost.
[0111]
  Next, the separation system decoding unit 205 separates and decodes the transport stream 204 into primary packets 206, 207, 208, 209, and 210 for each data type. Data buffer 212 and caption data buffers 213, 214, and 215.
[0112]
  That is, the system encoding and multiplexing unit 117 in FIG. 1 separates the multiplexed data by distinguishing the data by the identification code added to the secondary packet, and the delay buffers 110, 111, 112, The primary packets 206, 207, 208, 209, and 210 are reproduced as primary packets corresponding to the primary packets on the transmission side 115 and 116, respectively.
[0113]
  At this time, the primary packet to be reproduced from the secondary packet that has been lost without correcting the error cannot be reproduced and is lost.
[0114]
  The system time clock reference signal (PCR) 216 is similarly decoded, and the system time clock reproducing unit 217 reproduces the system time clock for synchronous reproduction.
[0115]
  The audio decoding unit 218 decodes the primary packet of the audio data buffer 211 to generate an audio signal 219 and outputs the audio signal 219 from the speaker 220.
[0116]
  Also, the video decoding unit 221 decodes the primary packet of the video data buffer 212 to form a television video signal 222 and sends it to the video synthesis unit 223.
[0117]
  In addition, the video composition unit 223 synthesizes a plurality of input video signals, that is, a television video signal, a caption video signal, a video signal indicating the state of the apparatus, and the like and displays them on the display 224.
[0118]
  FIG. 3 schematically shows the display screen 301 of the display 224. In the first embodiment, a television video is displayed on a part 302 of the display screen 301 by a video signal from the video decoding unit 221 and a subtitle is displayed on another subtitle display unit 303.
[0119]
  2 reads out the primary packets of the subtitle data buffers 213, 214, and 215, detects reception failure of the caption data, and there is no reception failure or reception failure has a predetermined frequency. The primary packet of subtitle data that can be replaced is sent to the decoding unit 226 for subtitles.
[0120]
  The subtitle decoding unit 226 decodes the primary packet according to the broadcast format, creates a subtitle video signal 227, and sends it to the video synthesis unit 223. Thereby, the subtitle is displayed on the subtitle display unit 303 of the display screen 301 (shown in FIG. 3) of the display 224.
[0121]
  At this time, the data decoding units 218, 221 and 226 control the output time based on the presentation time added to each primary packet and the time information 228 from the system time clock recovery unit 217. Thus, the output from each decoding unit is synchronized.
[0122]
  In some cases, like video data in terrestrial digital broadcasting, the decoding process is performed in accordance with the decoding time added to the primary packet, and the process is performed to output in accordance with the presentation time. .
[0123]
  The configuration of the demodulation unit 203, the separation system decoding unit 205, and the decoding units 218, 221, and 226, the demodulation process, the separation process, the system decoding process, and the procedure of the decoding process of each data are as follows. Since it is an existing technology, details are omitted.
[0124]
  Next, a method of detecting a reception failure of caption data in the caption replacement unit 225 will be described with reference to the flowchart shown in FIG. In the first embodiment, the reception failure is detected using the presentation time added to the caption data in the primary packet.
[0125]
  First, subtitle data having the earliest presentation time in the data buffer is obtained from the subtitle data buffers 213, 214, and 215 each having a plurality of subtitle data that can be replaced. In the case of this first embodiment, the primary packet of caption data is transmitted in the order of presentation time, so that the data sent to each data buffer the fastest is compared between the data buffers. It will be. At this time, for example, if there is something that does not hold the data in the data buffer, until the time before the predetermined time of the earliest presentation time (that is, the time when display is in time for the presentation time in consideration of the display processing time), It is possible to prevent the process from proceeding to the next step S12 and wait for data to arrive in the data buffer.
[0126]
  Next, a reception failure is determined for the caption data selected in step S11 (S12). In other words, it is determined that caption data having the same presentation time as the presentation time of the selected caption data does not have a reception failure, and caption data having a presentation time later than that is determined not to be normal caption data due to a reception failure. To do. Naturally, in steps S11 and S12, when all the data in the data buffer for captions has a reception failure, the caption data with less reception failure is selected from them.
[0127]
  Next, the caption data having no reception failure is sent to the caption decoding unit (S13). The caption data transmitted to the caption decoding unit 226 is decoded as described above and displayed on the screen.
[0128]
  After that, the subtitle data without the reception failure (subtitle data for which transmission has been completed) is discarded, and the non-normal subtitle data due to the reception failure is subtitle data later in time, so that it can be used later. Return to the original data buffer (S14).
[0129]
  If there is no end instruction, the process returns to step S11. If there is an end instruction, the process ends (S15).
[0130]
  As described above, it is possible to detect the reception failure by comparing the caption data of each data buffer. And it can output on a screen using subtitle data without reception failure.
[0131]
  In the above step S12, it is preferable that the presentation times coincide with each other in a plurality of subtitle data in each data buffer in the comparison, but the presentation time is provided at a predetermined fixed interval or within a predetermined time. When broadcasts are made such that the time is shifted, it is possible to compare in consideration of that.
[0132]
  As described above, the steps S11 and S12 constitute failure detecting means for comparing the identification codes added for each of the caption data between the plurality of caption data and detecting a reception failure of each caption data. The
[0133]
  Further, step S13 constitutes a selective transmission means for outputting the caption data determined by the failure detection means that there is no reception failure or the reception failure is less than a predetermined frequency to the caption output means.
[0134]
  That is, in the first embodiment, the presentation time is used as an example of the identification code.
[0135]
  Alternatively, as another example of the identification code, the decoding process is performed in accordance with the decoding time added to the primary packet and output in accordance with the presentation time like video data in terrestrial digital broadcasting. Since control may be performed, the reception failure may be detected using the decoding time as an identification code, and a replacement output in that case may be performed.
[0136]
  Alternatively, as another example of the identification code, for example, a subtitle dialog, a sentence, a line, a paragraph, or a code (for example, a serial number) added to a group of subtitles displayed at a time can be used. In any case, the identification code used in step S12 needs to include content that can identify caption data having the same content among a plurality of replaceable caption data.
[0137]
  In the first embodiment, detection of subtitle data reception failure is performed after the data buffers 213, 214, and 215. However, the present invention is not limited to this. For example, after decoding into subtitles, A reception failure can also be detected by comparing between subtitles.
[0138]
  Alternatively, immediately after the separation system decoding unit 205, each primary packet can be compared with the already accumulated primary packet to detect a reception failure and can be replaced. In this case, there is an advantage that it is not necessary to have a plurality of data buffers.
[0139]
  In addition to the television video and caption video, the video composition unit 223 displays a display 307 (shown in FIG. 3) indicating an incoming call of a mobile phone, a display 308 (shown in FIG. 3) showing an incoming email, For example, a bar graph 309 (shown in FIG. 3) of the error frequency indicating the reception status of the program may be combined and displayed as necessary.
[0140]
  Next, the operation at the time of reception failure of the reception device and the operation after recovery will be described.
[0141]
  Here, as an example, a manner mode is set for viewing a broadcast in a public place, and the output of audio is stopped and viewing is performed with subtitles.
[0142]
  First, the separation system decoding unit 205 is set to stop the separation of audio primary packets and system decoding, and to separate video and subtitle primary packets and system decoding. As a result, the voice output stops without outputting the voice primary packet 206.
[0143]
  Video and subtitle primary packets 207, 208, 209, and 210 are output to each buffer and displayed on the display 224 at the presentation time as described above. As a result, the user can view television images and subtitles.
[0144]
  If a reception failure such as a weak reception radio wave occurs temporarily and the allowable amount that data can be recovered by the error correction of the broadcasting system performed by the demodulation unit 203 is exceeded, some of the secondary packets are lost. , Primary packets of video and subtitles are missing.
[0145]
  However, the subtitle replacement unit 225 outputs the subtitle data by replacing the subtitle data with a plurality of subtitle data that can be replaced, so that the correct primary packet can be output for a while.
[0146]
  In mobile reception, reception is often temporarily lost due to fading or obstruction of radio waves by obstacles, and recovery is accompanied by movement. Therefore, the loss of the primary packet is recovered within 1 second in most cases thereafter.
[0147]
  If the interval between the broadcast times when a plurality of subtitle data that can be replaced is broadcasted, that is, the difference in delay time between the delay buffers 112, 115, and 116, is larger than the time until the reception failure is recovered, it is received before the reception failure. It is possible to output correct caption data by replacing the primary packet.
[0148]
  According to the receiving apparatus of the first embodiment, even when error correction cannot be completed using the replaceable subtitle data broadcast with a time interval as described above, replacement with another replaceable subtitle is performed. Since the subtitles are not interrupted, the user can follow the progress of the program while watching the subtitles, and can wait for the recovery of the reception failure without losing sight of the progress of the program.
[0149]
[Second Embodiment]
  Next, a different form of the broadcast program providing method and transmitting apparatus shown in the first embodiment will be described as a second embodiment.
[0150]
  In the second embodiment, the system encoding and multiplexing unit 117 of FIG. 1 is configured to increase or decrease the number of broadcasts of subtitle data that can be replaced within a range that fits in the broadcast band according to the total amount of transmission data. is doing.
[0151]
  In the second embodiment, only differences from the first embodiment will be described below.
[0152]
  Referring to FIG. 1, when the amount of transmission data is large in the encoding and multiplexing unit 117, the subtitle data read from the delay buffer 116 is discarded without being converted into secondary packets, and the amount of transmission data is small and the broadcast band is reduced. When there is room, subtitle data read from the delay buffer 116 is converted into a secondary packet.
[0153]
  If the above process is described with reference to the flowchart of FIG. 4, first, the transmission data amount is calculated (S1). The transmission amount in this case is video, audio, subtitles, and other than subtitle data such as the above-described program arrangement information (SI) and program specification information (PSI) that increase or decrease the number of broadcasts, that is, the primary of the delay buffer 116. Refers to the total amount of transmitted data other than packets.
[0154]
  Next, the amount of transmission data when subtitle data that can be replaced is added is calculated (S2), and it is determined whether or not it falls within the broadcast band (S3).
[0155]
  If the amount of data falls within the broadcast band in step S3, replaceable subtitle data is added (S4). If the amount of data does not fit in the broadcast band in step S3, replacement is possible. Discard without adding additional caption data (S5).
[0156]
  The above is performed, for example, every unit time or each time a primary packet of subtitle data that can be replaced is acquired.
[0157]
  In this way, replaceable subtitle data in which data is transmitted or not becomes replaceable subtitle data in which data is thinned irregularly as a result. Therefore, when the above broadcast is received, some of the subtitle data that can be replaced is originally missing due to the congestion of the broadcast band. However, the substitutable subtitle data that can be replaced can be handled in the same manner as the subtitle data that can be replaced due to a communication failure in the receiving apparatus described in the first embodiment. The data can be output by replacing the subtitles in the same manner as other normally received subtitle data.
[0158]
  When a plurality of subtitle data that can be replaced is broadcast, especially in the above-mentioned partial reception segment broadcast, especially one segment broadcast, it occupies most of the broadcast band, and other data broadcasts such as program arrangement information and program specification information are transmitted. There may be a problem in multiplexing. However, if a predetermined or higher broadcast band is secured, the number of subtitle data that can be replaced is reduced.
[0159]
  According to the broadcast program providing method and transmitting apparatus of the second embodiment, the number of subtitle data broadcasts that can be replaced is increased when the broadcast data is small, and the number of subtitle data broadcasts that can be replaced is decreased when the broadcast data is large. Therefore, subtitle data can be replaced and output using the broadcast band more effectively.
[0160]
  Further, even when caption data is intentionally lost in steps S3 and S5, it can be handled in the same way as an actual communication failure, and there is an advantage that it is not necessary to add a special mechanism to the receiving apparatus.
[0161]
  That is, in steps S1, S2, S3, S4, and S5, a part of the replaceable subtitle data is broadcast according to the data amount of other data other than the part of the data. Data amount adjusting means for controlling the data amount to be equal to or less than the broadcast band is configured.
[0162]
  Further, when the broadcast band and the data amount are compared in step S3, subtitle data that can be replaced up to the limit of the broadcast band may be added, and the total data amount is set to be somewhat smaller than the band. You can also. In terrestrial digital broadcasting, when the total data amount is smaller than the broadcast band, dummy data is automatically added to the secondary packet so that the final data amount is standardized.
[0163]
[Third Embodiment]
  Next, a different form of the receiving apparatus shown in the first embodiment will be described as a third embodiment.
[0164]
  In the receiving apparatus according to the third embodiment, the reception failure of each received replaceable subtitle data is not detected, and the replaceable subtitle data is sequentially decoded and displayed according to the presentation time. It is composed.
[0165]
  In the third embodiment, only differences from the first embodiment will be described below.
[0166]
  Referring to FIG. 2, the caption substitution unit sequentially outputs data at the presentation times of the buffers 213, 214, and 215 to the caption decoding unit 226. That is, subtitles are always overwritten and past subtitles are deleted.
[0167]
  According to the third embodiment, when there is no reception failure, subtitles are overwritten one after another by a plurality of subtitle data that can be replaced, but the viewer is unaware that the same content is overwritten. When a reception failure occurs in certain caption data, the caption is displayed by being replaced with another replaceable caption data in which no reception failure has occurred. That is, only by reducing the number of overwrites, the subtitles are correctly displayed until all replaceable subtitle data becomes a reception failure.
[0168]
  The third embodiment is the simplest method when the same subtitles are displayed in a superimposed manner and the user who is viewing does not notice.
[0169]
  However, when subtitles are displayed together with those displayed in the past, for example, the subtitle display unit 303 displays a plurality of past subtitles 304, 305, and 306, and each time a new subtitle is added, Alternatively, when the display is moved from 304 to 305, 306 and disappears at regular time intervals, the same subtitle is displayed twice or a plurality of times in the above configuration. . Therefore, from the presentation time, etc., those that are determined to be the same subtitle are overwritten or not displayed in the same place, and those that are determined to be different subtitles are moved sequentially from the current 304 subtitles to 305,306. It is preferable to configure to newly write to 304.
[0170]
  That is, if it demonstrates with the flowchart of FIG. 6, first, the presentation time of the last displayed subtitle will be memorize | stored (S21).
[0171]
  Next, the subtitle data that can be replaced are sequentially acquired at the presentation time (S22). Actually, it is acquired a little before the presentation time in consideration of the time required for processing until display. That is, a plurality of subtitle data that can be replaced is sequentially searched from the data buffers 213, 214, and 215, and subtitle data at a presentation time to be displayed at the present time is acquired.
[0172]
  Next, the presentation time of the caption data acquired in step S22 is compared with the presentation time of the caption displayed at the end of step S21 to determine whether or not the presentation times are the same (S23).
[0173]
  If the presentation time is the same in step S23, the caption is overwritten (S24). In this case, the subtitle data may be discarded without being overwritten without being overwritten. In addition, when the caption data has the same presentation time among a plurality of replaceable caption data, the presentation time may be delayed by the time for performing the processing (steps S22, S23, S24). There are cases where it is necessary to consider.
[0174]
  On the other hand, if the presentation time is different in step S23, the subtitles displayed in the past on the screen are moved to display the subtitles in a new line (S25). Old subtitles that protrude from the subtitle display section are deleted.
[0175]
  If there is no end instruction after steps S24 and S25, the process returns to step S21. If there is an end instruction, the process ends (S26). And when returning to step S21, the presentation time of the caption displayed in steps S24 and S25 is stored as the presentation time of the caption displayed last.
[0176]
  As described above, the subtitle data that can be replaced in the reception failure can be replaced with each other and output to the screen without providing a special mechanism for detecting the reception failure of the plurality of subtitle data that can be replaced.
[0177]
  Thus, the steps S21, S22, S23, S24, and S25 constitute overwriting output means for overwriting the replaceable subtitle data on the screen.
[0178]
  Alternatively, if the overlapping subtitle data is discarded without being overwritten in step S24, subtitle data that can replace the plurality of subtitle data that can be replaced is obtained in steps S21, S22, S23, S24, and S25. A selective sending means for selecting and displaying so as not to overlap each other is configured.
[0179]
  According to the third embodiment, when there is no reception failure, subtitles are overwritten one after another by a plurality of subtitle data that can be replaced, but the viewer is unaware that the same content is overwritten. When a reception failure occurs in certain caption data, the caption is displayed by being replaced with another replaceable caption data in which no reception failure has occurred. That is, only by reducing the number of overwrites, the subtitles are correctly displayed until all replaceable subtitle data becomes a reception failure.
[0180]
  Furthermore, when displaying subtitles, the last displayed subtitle is processed as a subtitle that can be replaced, that is, whether it is the same content and overwritten or displayed on a new line. It can also be used in a caption display method that holds multiple lines. In mobile reception, in particular, there are many opportunities to look away from the display while paying attention to the surroundings, so display multiple lines of past subtitles so that viewers do not miss subtitles. It is possible to provide a receiving device that can increase interest and improve the audience rating.
[0181]
[Fourth Embodiment]
  Next, a different form of the receiving apparatus shown in the first embodiment will be described as a fourth embodiment.
[0182]
  The receiving apparatus according to the fourth embodiment is configured to automatically display subtitles when video and audio reception failures occur, and to automatically delete subtitles when reception failures are restored.
[0183]
  In the fourth embodiment, only differences from the first embodiment will be described below.
[0184]
  Referring to FIG. 2, when the primary packet is missing in the audio decoding unit 218 and the video decoding unit 221, the error signals 229 and 230 are output to the video synthesis unit 223, respectively. The subtitle display is switched in the video composition unit 223 in accordance with the error signals 229 and 230.
[0185]
  If described with reference to the flowchart shown in FIG. 7, first, settings are made to output audio and video (S31). That is, the video composition unit 223 is set so as not to display subtitles, and normally, the subtitles are turned off and the television is normally viewed.
[0186]
  In the fourth embodiment, the video synthesizing unit 223 synthesizes the caption video when there is at least one error signal of the error signals 229 and 230, and stops the synthesis when neither error signal is present. Set to. Further, the separation system decoding unit 205 is set to always perform separation and decoding of the primary packets of audio and video sequential subtitles.
[0187]
  Next, it is determined whether or not there is a reception failure (S32). In the fourth embodiment, when one of the audio and video error signals 229 and 230 is transmitted, it is determined that there is a reception failure.
[0188]
  If there is no reception failure in step S32, the determination in step S32 is repeated. That is, the broadcast program can be normally received, and the user views the broadcast program with the video displayed on the display and the sound output from the speaker.
[0189]
  On the other hand, if there is a reception failure in step S32, settings are made to output audio, video, and subtitles (S33). That is, this is a case where a reception failure such as a temporarily weakened received radio wave occurs. In the fourth embodiment, when the demodulating unit 203 exceeds an allowable amount that data can be restored by error correction of the broadcasting system, the primary packet of video or audio is lost and the video or audio is interrupted. Then, error signals 229 and 230 indicating data loss in the audio decoding unit 218 and the video decoding unit 221 are issued, and the video synthesis unit 223 starts synthesis of the subtitle video signal 227. Then, the subtitle is displayed on the display 224.
[0190]
  At this time, as shown in the first embodiment, the subtitle data is replaced with a plurality of series of primary packets and the subtitle data is output, so the video composition unit 223 receives the subtitle data. The correct caption video signal from the decoding unit 226 is input. Therefore, the video synthesizing unit 223 can synthesize a caption video signal and output it to the display 224.
[0191]
  Next, it is determined whether there is normal reception, that is, there is no reception failure (S34). In the fourth embodiment, when the error signals 229 and 230 for both audio and subtitles are not transmitted, it is determined that the reception is normal.
[0192]
  In mobile reception, it is often impossible to receive temporarily due to fading or shielding of radio waves by obstacles, and since it recovers with movement, video and audio errors are subsequently recovered. Then, the audio decoding unit 218 and the video decoding unit 221 stop the error signals 229 and 230.
[0193]
  If the reception is not normal in step S34, that is, if there is a reception failure, the determination in step S34 is repeated. That is, the reception failure continues.
[0194]
  On the other hand, if it is determined in step S34 that there is normal reception, that is, there is no reception failure, it is determined whether a period without reception failure continues for a predetermined period (S35).
[0195]
  If it is determined in step S35 that the period without reception failure does not continue for a predetermined period, the process returns to step S34. That is, it is a state in which a predetermined time has not yet elapsed after recovery from the reception failure.
[0196]
  On the other hand, if a period of no reception failure continues in step S35 for a predetermined period, the subtitle output is stopped and audio and video are set to be output (S36). That is, the video composition unit 223 is set so as not to display the subtitle, and the subtitle is turned off to return to the state where the television is normally viewed.
[0197]
  Then, the process returns to step S32 and repeats until an end instruction is given (S37).
[0198]
  As described above, the caption can be displayed when a reception failure occurs, and the caption can be erased when the reception failure is recovered.
[0199]
  As described above, the subtitle output start means for controlling the subtitle output means is configured to start displaying the subtitles by the subtitle data when the reception failure occurs in the video data or the audio data in steps S32 and S33. The
[0200]
  Also, subtitle output stopping means for controlling the subtitle output means to stop the display started by the subtitle output start means when the reception failure of the video data or audio data is recovered by steps S34 and S36. Composed.
[0201]
  In particular, when the reception failure of the video data or audio data is recovered by steps S34, S35, and S36, the display started by the caption output start unit is stopped after a certain period of time when no reception failure occurs. As described above, subtitle output stopping means for controlling the subtitle output means is configured.
[0202]
  Further, although not described, the processing may be terminated from the above steps due to power-off of the receiving apparatus, reception setting, output setting change, and the like.
[0203]
  According to the fourth embodiment, when a reception failure occurs, captions are displayed, and the viewer can wait for recovery of the reception failure while following the progress of the program using the captions. In addition, it is possible to provide a receiving apparatus capable of watching a normal program when the reception failure is recovered and the captions disappear.
[0204]
  In this fourth embodiment, subtitles are configured to display subtitles when there is an error in either video data or audio data, but only when there is an error in audio data. It is also possible to configure. However, if there is an error in the video data and the video cannot be displayed, the viewer may not be able to obtain information from the display device, which may be boring, and the viewer keeps an eye on the screen. Therefore, even if there is only an error in the video data, displaying subtitles and attracting the user's vision to the display will immediately enter the field of view when the video resumes, and the user will be more satisfied. Can be given.
[0205]
  In addition, when a video reception failure occurs, the reception state is often poor, followed by an audio reception failure. For this reason, even if there is only a video reception failure, it is possible to display the subtitles before the audio is interrupted if the audio reception failure continues if the subtitles are displayed. As a result, the user is freed by time to get used to the correspondence between audio and subtitles, and information is less likely to be missed even when the audio is interrupted.
[0206]
  Especially in the partial reception segment mainly used for mobile reception in the terrestrial digital broadcasting standard, error correction of audio and video is performed with the same redundancy, so reception failures often occur at the same level, and the amount of information In many cases, an image with a large amount of video is stochastically unable to correct an error first, that is, a reception failure. Therefore, it is highly effective that the caption can be displayed before the sound is interrupted by controlling the display of the caption using both the audio and video error signals.
[0207]
  In addition, when the frequency of errors detected in the error correction of the secondary packet unit in the demodulator 203 is signaled (error signal 229) and the reception state deteriorates by using the signal, the reception failure actually occurs. It is more preferable to display subtitles before video and audio are interrupted. In that case, even if the video and audio are not interrupted, if the frequency of errors detected in the secondary packet unit error correction in the demodulator 203 exceeds a predetermined threshold value, a reception failure has occurred. Judge that.
[0208]
  This determination of reception failure can be used in steps S32 and S34 in the flowchart of FIG. In this case, subtitles can be displayed more reliably before reception failure, and the viewer can naturally move from video and audio to viewing with subtitles.
[0209]
  In addition, as in the fourth embodiment, it is more effective for viewers to view video and audio from subtitles by recovering from reception failure or subtitle display conditions and ending the subtitles after a certain period of time. Since it can move naturally, it is more preferable. Alternatively, it may be difficult to see the captions when the subtitles are repeatedly displayed and disappeared. For this reason, it is preferable to delete the caption after a good reception state continues for a certain period.
[0210]
  Alternatively, when the reception state becomes good, the subtitle may be erased according to a user instruction. In this case, for example, it is preferable to display the bar graph 309 or the like on the display with the reception state as the frequency of errors so that the reception state can be determined.
[0211]
[Fifth Embodiment]
  Next, in the fifth embodiment of the present invention, as in the first embodiment, data multiplex broadcasting is possible in broadcasting based on the transmission method of Japanese terrestrial digital broadcasting as an example of digital broadcasting capable of data multiplex broadcasting. An example of a transmission apparatus and a reception apparatus that transmit digital broadcasting will be described. The transmission apparatus according to the fifth embodiment is configured to broadcast each of a plurality of replaceable video data with a time interval equal to or greater than the time interleave length in addition to the plurality of replaceable subtitle data.
[0212]
  In the fifth embodiment, only differences from the first embodiment will be described below.
[0213]
  Figure 8The second5 is a part of a block diagram of a transmission apparatus according to a fifth embodiment, and shows a part that is partially different from the transmission apparatus of FIG. 1, and other parts are the same as those in FIG. FIG. 9 is a part of a block diagram of a receiving apparatus according to the fifth embodiment of the present invention. FIG. 9 shows a part different from the receiving apparatus in FIG. 2, and the other parts are the same as those in FIG. It is omitted. 8 and 9, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals.
[0214]
  First, the overall configuration will be described.
[0215]
  The transmission apparatus shown in FIG. 8 has a video data encoding unit 105 as an example of video encoding means for encoding video data, and delays the video data encoded by the encoding unit 105. A delay buffer 111 and a delay buffer 901 that delays the encoded video data with a delay time that is shorter than the delay time of the delay buffer 111 that delays the video data by a time interleave length or more.
[0216]
  The transmission apparatus receives the encoded video data from the delay buffer 111 that delays the video data and the delay buffer 901 that delays the video data, and creates a data stream that multiplexes them. A system encoding / multiplexing unit 117 is provided as an example of the creating means.
[0217]
  In addition, the receiving apparatus illustrated in FIG. 9 includes a video decoding unit 221, a video synthesis unit 223, and a display 224 as an example of a video output unit that outputs the video data.
[0218]
  In addition, when a reception failure occurs in some of the replaceable video data, the receiving device uses the replaceable video data different from the video data in which the reception failure has occurred to replace the video output means. An image replacement unit 904 is provided as an example of image replacement means for replacing the output.
[0219]
  Although omitted in FIG. 9, the receiving apparatus shown in FIG. 2 is an example of a receiving unit that receives a broadcast including a plurality of replaceable video data broadcasted at time intervals. A unit 201, a demodulator 203, and a separation system decoder 205.
[0220]
  Next, a broadcast program providing method will be described with reference to FIG.
[0221]
  Broadcast program data is supplied from an audio data input unit 101, a video data input unit 102, and a subtitle data input unit 103, respectively, and encoded by encoding units 104, 105, and 106, respectively. 107, 108 and 109 are sent to the delay buffers 110, 111 and 112, respectively, as in the first embodiment.
[0222]
  In the fifth embodiment, the primary packet 108 output from the video data encoding unit 105 is further duplicated to create another primary packet, which is sent to a delay buffer 901 different from the delay buffer 111. did. That is, as an example of a plurality of replaceable video data, a primary packet having the same video data content is sent to a plurality of delay buffers 111 and 901.
[0223]
  In the fifth embodiment, a copy of the primary packet 109 output from the caption data encoding unit 106 is transmitted to only the delay buffer 115, unlike the first embodiment. That is, as an example of a plurality of subtitle data that can be replaced, a primary packet having the same subtitle data content is sent to two locations of the plurality of delay buffers 112 and 115.
[0224]
  The system encoding and multiplexing unit 117 reads out the primary packets of the delay buffers 110, 111, 901, 112, and 115, and distinguishes the difference between the primary packets, in this case, the difference between the buffers. Is converted again into a secondary packet (TSP) to which an identification code is added. Then, the secondary packets are multiplexed, a transport stream (TS) 118 (shown in FIG. 1) in which the secondary packets are continuous is created, and is sent to the modulation unit 119 (shown in FIG. 1).
[0225]
  In the fifth embodiment, the delay time of the delay buffer 901 is an example of a method of broadcasting each of the plurality of replaceable video data with a time interval longer than the time interleave length. Is made shorter than the delay time of the delay buffer 111, and the difference between the delay times of the delay buffers is set to be twice the time interleave length.
[0226]
  Thereafter, the same processing as in the first embodiment is performed and broadcast as a broadcast radio wave.
[0227]
  Next, the processing flow of the receiving apparatus that receives a broadcast program will be described with reference to FIG.
[0228]
  Broadcast radio waves are received by an antenna, converted into a baseband signal (or intermediate frequency signal) 202 (shown in FIG. 2) of a broadcast program of a selected broadcast station, and then demodulated by a demodulator 203 (shown in FIG. 2). The reproduction of the transport stream (TS) 204 (shown in FIG. 2) in which (TSP) is continuous is the same as the processing in FIG. 2 of the first embodiment.
[0229]
  Next, the separation system decoding unit 205 separates and decodes the transport stream 204 into primary packets 206, 207, 902, 208, and 209 for each data type, respectively. Data buffers 212 and 903 and caption data buffers 213 and 214.
[0230]
  That is, the system encoding / multiplexing unit 117 in FIG. 8 separates the multiplexed data by distinguishing the data by the identification code added to the secondary packet, and the delay buffers 110, 111, 901, FIG. The primary packets 206, 207, 902, 208, and 209 are reproduced as primary packets corresponding to the primary packets on the transmitting side at 112 and 115, respectively.
[0231]
  In the fifth embodiment, the video replacement unit 904 reads the primary packets of the video data buffers 212 and 903 to detect a video data reception failure, and there is no reception failure or a reception failure occurs at a predetermined frequency. The primary packet of video data with a few replacements is sent to the video decoding unit 221.
[0232]
  In the fifth embodiment, the subtitle replacement unit 225 reads the primary packets of the subtitle data buffers 213 and 214, detects subtitle data reception failure, and has no reception failure or reception failure at a predetermined frequency. The primary packet of subtitle data that can be replaced is sent to the decoding unit 226 for subtitles.
[0233]
  Then, the video decoding unit 221 decodes the primary packet from the video replacement unit 904 into a television video signal 222 and sends it to the video composition unit 223.
[0234]
  Also, the caption decoding unit 226 decodes the primary packet from the caption replacement unit 225 to generate a caption video signal 227 and sends it to the video synthesis unit 223.
[0235]
  Thereby, the video and the subtitle are displayed on the display 224.
[0236]
  The method of sending the primary packet of replaceable video data in the video replacement unit 904 that has no reception failure or a reception failure less than a predetermined frequency to the video decoding unit 221 is the subtitle data in the first embodiment. It is possible to use the same method as the method of detecting the reception failure of the caption data by comparing the presentation times. In this case, since the video data is broadcast in the order of the decoding time, it is more preferable to use the decoding time instead of the presentation time.
[0237]
  In other words, the video data reception failure is detected by comparing the decoding times of the video data in the data buffers 212 and 903 for each video.
[0238]
  According to the transmission apparatus of the fifth embodiment, since the difference between the delay times of the delay buffers 111 and 901 is greater than or equal to the time interleave length, in addition to the replaceable subtitle data, the replaceable subtitle data It is possible to provide a broadcast program that broadcasts each of the video data with a time interval greater than or equal to the time interleave length.
[0239]
  Further, according to the broadcast program providing method, the modulation unit broadcasts a plurality of replaceable subtitle data and a plurality of replaceable video data a plurality of times with a time interval equal to or longer than the time interleave length of the broadcast system. Data diffusion by the error correction method 119 (shown in FIG. 1) does not overlap in time not only between the plurality of replaceable subtitle data but also between the plurality of replaceable video data. Therefore, even when the error cannot be corrected by the error correction of the broadcasting system, it is highly likely that another replaceable video data among the replaceable video data can be normally received. It is possible to provide a broadcast program that can continue displaying subtitles and video even if error correction cannot be completed.
[0240]
  In the broadcast program providing method, the broadcast station can easily adjust the number of broadcasts of the replaceable video data and the time interval of each broadcast time to be broadcast a plurality of times according to the usage situation of the viewer. Has the advantage of being possible. In particular, there is a special advantage that can be changed without changing the broadcasting standard.
[0241]
  According to the receiving device of the fifth embodiment, even when error correction cannot be completed, replacement output can be performed with another subtitle that can be replaced or another video that can be replaced. The user can follow the progress of the program while watching the subtitles and the video, and can wait for the recovery of the reception failure without losing sight of the progress of the program.
[0242]
  In the first embodiment and the fifth embodiment, the time interval for broadcasting a plurality of replaceable subtitle data is set to twice the time interleave length. However, the time interval may be longer than the time interleave length, and more preferably. 1 second or longer. This is because in practice, there are many cases in which reception failure while moving on a train station, a waiting place such as a bus stop, or a train continues for less than one second. However, even if a reception failure occurs due to the movement of a person or a car at a waiting place or the movement of a vehicle such as a train or a bus due to movement of a vehicle, even if a reception failure occurs in actual use, it is 1 This is because most cases recover in about a second. More preferably, the delay time interval is set to 2 seconds or more, which is twice as long, so that even if the reception situation deteriorates in the complicated terrain near the city, it can be more reliably replaced at another time. Subtitle data can be replaced.
[0243]
  In order not to make the buffer of the receiving apparatus larger than necessary, the time intervals at which each of the replaceable subtitle data is broadcast with a time interval, that is, the above delay time interval should be 1 minute or less. Is preferred. In addition, if this delay time value is large, the difference between the presentation time and the data transmission time becomes large, so that the subtitle output can be replaced after the power is turned on or after the channel is changed. Since time increases, it is more preferable to set it to 15 seconds or less.
[0244]
  This is the time required for the viewer to roughly understand the scene so that most of the commercials in the broadcast program are organized in units of 15 seconds. Therefore, on the contrary, the viewer does not necessarily care about the content of the program for about 15 seconds after turning on the power or changing the channel. On the other hand, after 15 seconds, the user is in a position to grasp the contents of the program and enjoy the program. Therefore, it is preferable that the data can be replaced as described above within 15 seconds.
[0245]
  Further, in the first embodiment, as a plurality of replaceable subtitle data that has been transmitted, original subtitle data (corresponding to data stored in the delay buffer 112) is separately replaced with subtitle data (delay buffer). 115 corresponding to the data stored in 115 and 116), and subtitle data that can be replaced a total of three times is broadcast. However, another subtitle data that can be replaced is 1 as in the fifth embodiment. The subtitle data that can be replaced twice in total can be broadcast. Alternatively, another subtitle data that can be replaced can be broadcast three or more times, and a total of four or more subtitle data that can be replaced can be broadcast.
[0246]
  In the first embodiment, the third embodiment, the fourth embodiment, and the fifth embodiment, the subtitle output is replaced and output at the time of reception failure using all of the transmitted subtitles that can be replaced. However, the present invention is not limited to this configuration. Only a part of the plurality of replaceable subtitle data broadcasted above is used, and the substituting output of the subtitle data with reception failure is performed in the receiving apparatus. It can also be done.
[0247]
  In other words, a plurality of replaceable subtitle data is broadcast as the replaceable subtitle data at the broadcasting station, and a part of the replaceable subtitle data broadcast according to the performance of the receiving apparatus is used. Thus, the replacement output at the time of reception failure is configured.
[0248]
  In particular, when performing mobile reception, the receiving apparatus is limited in terms of the capacity of the data buffer for captions and the processing speed, so a configuration using a part of caption data that can be replaced according to performance is suitable. In this case, the storage capacity of the receiving apparatus can be reduced by using subtitle data that can be replaced with subtitle data having a large delay time in the delay buffer in FIG.
[0249]
  Alternatively, the presence of a plurality of subtitle data that can be replaced can be presented to the viewer, and the subtitle data that can be used for replacement output can be selected from the viewer. Alternatively, a plurality of combinations of a plurality of subtitle data that can be automatically replaced are sequentially selected, and a frequency at which the replacement processing is performed for each combination of the plurality of subtitle data that can be replaced is calculated. It is also possible to adopt a combination of a plurality of replaceable subtitle data that is frequently replaced.
[0250]
  In the first embodiment, the third embodiment, and the fourth embodiment described above, the video decoding unit 221 is configured to output the last video with no error when video data is missing. Is preferred.
[0251]
  Alternatively, the video decoding unit can be configured to display a stored past video or a video that has been subjected to various processing using the past video. For example, the reduced videos are displayed in sequence every few seconds, part of the video is enlarged or reduced, the color is changed, or the shape is distorted.
[0252]
  As a result, the user can wait for the recovery of the reception failure while following the progress of the program with subtitles that are output by replacement using a plurality of subtitle data that can be replaced at the time of reception failure while enjoying watching the changed scene. .
[0253]
  Or, when the reception failure is prolonged, the scene of the broadcast program may change, and the progress of the program obtained by the past video and the subtitle often does not match. Therefore, it is more preferable that the video is gradually erased, that is, processed and output so as to fade out when the video reception failure continues for a certain period. In this case, by setting so that the video is gradually erased when the video reception failure continues for 4 to 10 seconds from the average timing at which the TV broadcast screen changes, there is less discomfort due to the progress of the program and the discrepancy with the video preferable.
[0254]
  In the first to fifth embodiments, the terrestrial digital broadcasting standard is used as the broadcasting method. However, the broadcasting method is not limited to the terrestrial digital broadcasting standard, and other time interleaving processing is performed. It is possible to apply to digital broadcasting capable of data multiplex broadcasting of the standard to be performed. In other words, when combined with a system that performs time interleaving processing that excels in mobile reception, such as the Japanese terrestrial digital broadcasting system, it is more effective to replace more effectively with a small number of replaceable subtitle data. Caption data can be output. This is because the time-interleave process corrects most of the reception failures due to fading, so the frequency of reception failures that could not be corrected is reduced, and replaceable subtitle data that was broadcast longer than the time interleave length. This is because it is probabilistically less likely to become a reception failure at the same time.
[0255]
  In the broadcasting system of the standard of digital broadcasting, generally, data such as video, audio, and subtitles is made redundant by adding parity and spread by interleaving processing on the frequency axis and the time axis. As a result, even when reception of radio waves is interrupted partially or temporarily, the receiving apparatus can perform error correction and output correct data.
[0256]
  The configuration of broadcasting each of a plurality of subtitle data that can be replaced in the embodiment of the present invention has the same purpose in providing correct data to the viewer. However, error correction such as addition of parity in the above broadcasting system is possible. Compared with the processing for the time interleaving processing is configured in close relation to the broadcasting system, that is, the transmission / reception device, and determined by the standard, TurnThe biggest difference is that it is configured as a method of providing a set. Therefore, there is an advantage that it is possible to coexist with a broadcast program that does not use this configuration without making a large special change in the program broadcast transmission / reception apparatus.
[0257]
  That is, in the fifth embodiment, a plurality of subtitle data that can be replaced at the time of creation of the primary packet is created, or a plurality of subtitle data that can be replaced by duplicating the primary packet is created, and one of them is created. The next packet is reconstructed into a secondary packet and multiplexed. With this configuration, it is possible to broadcast a plurality of replaceable subtitle data without changing the broadcasting standard. That is, in the broadcasting system, since a secondary packet stream of continuous secondary packets is encoded and modulated for broadcasting, the present inventionDigital broadcasting handled byThe contents of the primary packet can be edited at the stage of program organization, rather than changing the broadcast standard, as long as it is within a certain standard as a broadcasting system.
[0258]
  Therefore, replaceable subtitle data is simply duplicated data broadcast from a receiver that does not support the reception failure replacement method described above, and does not interfere with reception. This is handled in the same way as selectable Japanese subtitles and English subtitles, for example.
[0259]
  For example, the receiver corresponding to the reception failure replacement method notifies the presence of a plurality of subtitle data that can be replaced by the above-described program arrangement information (SI) or program specification information (PSI), and the receiver side You may comprise so that the replacement output by a reception failure may be started automatically.
[0260]
【The invention's effect】
[0261]
  As is clear from the aboveAccording to the receiving device of the present invention,Digital broadcasts with time interleave processingReceiving a broadcast program, and subtitle data is replaced with another replaceable subtitle data and output even when the reception condition is temporarily degraded due to the error correction method standard of the broadcast transmission method. be able to.
[0262]
[Brief description of the drawings]
[FIG. 1] FIG.Is the first1 is a block diagram of a transmission apparatus using a broadcast program providing method according to an embodiment. FIG.
[FIG. 2] FIG.Of the present inventionIt is a block diagram of the receiver of 1st Embodiment.
FIG. 3 is a diagram for explaining a display screen of the receiving apparatus.
FIG. 4Is the firstIt is a flowchart for demonstrating the structure which changes the frequency | count of broadcast of subtitle data which can be replaced of the transmitter using the broadcast program providing method of the second embodiment.
FIG. 5 is a flowchart for explaining a method of detecting a reception failure of caption data in the receiving apparatus of the first embodiment.
FIG. 6 is a flowchart for explaining subtitle data replacement of a receiving apparatus using the broadcast program providing method according to the third embodiment of the present invention.
FIG. 7 is a flowchart for explaining subtitle display of the receiving apparatus according to the fourth embodiment of the present invention;
FIG. 8Is the firstIt is a block diagram of the transmitter which used the provision method of the broadcast program of 5 embodiment.
FIG. 9 showsOf the present inventionIt is a block diagram of the receiver which used the provision method of the broadcast program of 5th Embodiment.
FIG. 10 is a diagram for explaining a conventional broadcast program providing method;
[Explanation of symbols]
  101, 102, 103 ... data input section,
  104, 105, 106 ... encoding unit,
  107, 108, 109 ... primary packets,
  113 ... System time clock,
  114 ... presentation time,
  110, 111, 112, 115, 116, 901 ... delay buffer,
  117... System encoding and multiplexing unit,
  118 ... Transport stream,
  119: modulation unit,
  120 ... System time clock reference signal,
  121 ... baseband signal (or intermediate frequency signal),
  122... Transmitter
  201 ... receiving part,
  202 ... baseband signal (or intermediate frequency signal),
  203 ... demodulator,
  204 ... Transport stream,
  205 ... Separation system decoding unit,
  206, 207, 208, 209, 210, 902 ... primary packets,
  211, 212, 213, 214, 215, 903 ... data buffer,
  216 ... System time clock reference signal,
  217 ... System time clock reproduction unit,
  218, 221, 226 ... Decoding unit,
  219 ... Audio signal
  220 ... speaker,
  222 ... TV video signal,
  223 ... Video composition unit,
  224 ... display,
  225: Subtitle replacement unit,
  227 ... Subtitle video signal,
  229 ... error signal,
  904 ... Video replacement unit.

Claims (2)

In a receiving apparatus for receiving digital broadcasting capable of data multiplex broadcasting,
Receiving means for receiving a broadcast including a plurality of replaceable subtitle data broadcasted at time intervals;
Subtitle output means for outputting the subtitle data received by the receiving means;
Subtitle replacement means for replacing the output of the subtitle output means with another replaceable subtitle data different from the caption data in which the reception failure has occurred when there is a reception failure in some of the replaceable subtitle data And having
A receiving apparatus, comprising: subtitle output start means for controlling the subtitle output means so as to start displaying subtitles by the subtitle data when a reception failure occurs in video data or audio data. The receiving device according to claim 1 ,
A subtitle output stop unit that controls the subtitle output unit to stop the subtitle output started by the subtitle output start unit when the reception failure of the video data or the audio data is recovered. Receiver device.

Images