JP2007281868A - Transmission apparatus and receiving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission apparatus and a receiving apparatus capable of providing zapping applicable even to a live broadcast program. <P>SOLUTION: The transmission apparatus 100 includes: a first transmission line coding section 110, a second transmission line coding section 120, and a third transmission line coding section 130 for respectively coding data such as video included in a multiplexed TS on respective transmission lines; a zapping data generating section 140 for generating zapping data; and a communication section 160 for communicating with an IP network 15, and the zapping data generating section 140 includes: transcode sections 141, 142, 143 for respectively converting 1 to 3ch program data into zapping data at a low bit rate; a multiplexer section 144 for multiplexing the zapping data; and a fourth transmission line coding section 150 for coding the multiplexed zapping data on the fourth transmission line. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to, for example, a transmission apparatus and a reception apparatus that perform streaming transmission of moving image and audio data through a plurality of channels.

  In recent years, in addition to information transmission systems using broadcast waves such as terrestrial waves, satellite waves, and CATV (cable TV), those using communication lines are becoming widespread. In an information transmission system using an IP network, which is one of them, for example, when performing IP multicast communication, a stream is transmitted from a transmission device using different multicast addresses as channels, and a video is selected by selecting a channel on the reception device side. Data of audio, text, still images, etc. (hereinafter referred to as “video etc.”) can be reproduced and provided to the user as a program of the channel.

  However, for example, in an IP network that performs information transmission on a best-effort basis by packet transmission, when streaming data such as video, the transmission delay fluctuation in the transmission path is usually absorbed or lost during transmission. Buffering time (usually several seconds to several tens of seconds) to absorb transmission path uncertainty, such as waiting for retransmission of received packets or performing error recovery by FEC (Forward Error Correction) after deinterleaving Is required.

  Therefore, in a conventional information transmission system using an IP network, when switching a program to be viewed by a user, a period from when the channel is switched to when playback of data such as video of the program transmitted on the channel after switching is started. Since a delay corresponding to the buffering time always occurs, it is difficult to browse each program broadcast on a plurality of channels sequentially at a high speed (hereinafter referred to as “zapping”) when the channel is switched. There was a problem.

  For the purpose of solving this problem, for example, those disclosed in Patent Documents 1 and 2 have been proposed.

  First, what is disclosed in Patent Document 1 is that data for zapping, specifically, a part of a program, a digest, a representative screen, a program title, and the like is accumulated in advance on the receiving device side, When there is a request for channel selection, the stored zapping data is presented from when the channel selection request is received until playback of the broadcast program can be started. Patent Document 1 describes that this configuration allows the viewer to know the outline of the program that the user wants to watch without waiting for the playback waiting time after switching of the program to be received and to perform high-speed zapping. ing.

  Next, what is shown in Patent Document 2 is that the head part data of the program stored in the distribution server is stored in advance on the receiving device side and stored in the server while the head part data is being reproduced. Reception of program data is started, and the image of the first partial data is switched to the image of the received data. Specifically, what is disclosed in Patent Document 2 is that, for example, when a certain genre is selected in a VOD (Video On Demand) service, the first part data of a program in the genre is accumulated in advance to generate a zapping stream. By configuring, it is possible to provide viewers with zapping within the genre.

JP 2003-324711 A JP 2004-194294 A

  However, since the configuration disclosed in Patent Document 1 presents data stored in advance on the receiving device side during the reproduction waiting time after channel switching, it is presented at the reproduction waiting time when a live broadcast program is selected. There was a problem that things would be different from the video during the live broadcast.

  Further, in the case of the one disclosed in Patent Document 2, since it is necessary for the receiving apparatus side to store the first part data of each program in advance in order to provide zapping, the zapping stream is configured. However, there is a problem that it cannot be applied to broadcast programs including live broadcast programs.

  The present invention has been made to solve the conventional problems, and an object of the present invention is to provide a transmission device and a reception device that can provide zapping applicable to a live broadcast program.

  The transmission apparatus of the present invention includes a first information input unit that inputs a plurality of first information encoded at a predetermined bit rate, and the plurality of first information at a bit rate lower than the bit rate. Second information input means for inputting a plurality of converted second information, multiplexing means for multiplexing the plurality of second information and outputting the multiplexed second information, and the plurality of first information differ from each other And a transmission means for transmitting the multiplexed second information on a specific channel different from the channel.

  With this configuration, the transmission apparatus of the present invention transmits a plurality of first information through different channels, and transmits multiplexed second information through a specific channel different from these channels. By constantly receiving information, it is possible to reproduce low bit rate program data corresponding to the program data in a period until a new channel is selected by the receiving device and the program data of the channel can be reproduced, It is possible to provide zapping applicable to a live broadcast program.

  In addition, the transmission apparatus of the present invention receives the plurality of first information, converts the plurality of first information to a bit rate lower than the bit rate, and outputs the plurality of second information. It has the structure provided with the conversion means.

  With this configuration, the transmission apparatus of the present invention generates a plurality of second information at a low bit rate inside the apparatus, and therefore transmits the plurality of first information through channels different from each other, and a specific channel different from these channels. Multiplexed second information can be transmitted.

  Furthermore, the transmission apparatus of the present invention has a configuration including delay means for delaying a time at which the plurality of first information is transmitted by the transmission means by a predetermined time.

  With this configuration, the transmission device of the present invention can transmit the first information and the second information in synchronization.

  The receiving apparatus of the present invention includes channel selection means for selecting a predetermined channel for receiving one of a plurality of pieces of first information encoded with an information source at a predetermined bit rate; Receiving means for receiving channel selection first information and a plurality of second information transmitted on a specific channel regardless of the channel; and first transmission path decoding means for decoding the selected first information; Information output from one of the second transmission path decoding means for decoding the received plurality of pieces of second information, and the first transmission path decoding means and the second transmission path decoding means. Information selection output means for selecting and outputting, wherein the plurality of second information is obtained by converting the plurality of first information to a bit rate lower than the bit rate, respectively. Means for selecting the first channel in a period from when the new channel is selected until transmission path decoding of the first information related to the new channel is completed when a new channel is selected by the channel selection means; 2 Select a transmission path decoding means and output second information at a low bit rate corresponding to the first information related to the new channel, and select the first transmission path decoding means after the elapse of the period. Thus, the first information relating to the new channel is output.

  With this configuration, when a new channel is selected by the channel selection unit, the receiving apparatus of the present invention can perform a process from the selection of a new channel to the completion of transmission line decoding of the first information related to the new channel. In the period, the second transmission path decoding means is selected and the second information of the low bit rate corresponding to the first information related to the new channel is output, and after the elapse of the period, the first transmission path decoding means Since the first information related to the new channel is selected and zapping is applicable, it is possible to provide zapping applicable to a live broadcast program.

  Further, the receiving apparatus of the present invention is selected by channel selecting means for selecting a predetermined channel for receiving one of a plurality of pieces of first information encoded at a predetermined bit rate. Receiving means for receiving the selected first information of the channel and a plurality of second information transmitted on a specific channel regardless of the channel; and first transmission path decoding means for decoding the selected first information. And second transmission path decoding means for decoding the received plurality of second information, and first information source decoding means for decoding the first information subjected to transmission path decoding. The second information source decoding means for decoding the plurality of pieces of second information subjected to transmission path decoding, and any one of the first information source decoding means and the second information source decoding means Select and output information to be output Information selection output means, wherein the plurality of second information is obtained by converting the plurality of first information to a bit rate lower than the bit rate, and the information selection output means includes the channel When a new channel is selected by the selection means, the second information source decoding is performed in a period from when the new channel is selected until the information source decoding of the first information related to the new channel is completed. A second bit information having a low bit rate corresponding to the first information related to the new channel is selected, and after the period, the first information source decoding unit is selected and the new information is selected. It has the structure which outputs the 1st information which concerns on a channel.

  With this configuration, when a new channel is selected by the channel selection unit, the receiving apparatus of the present invention can perform the process from the selection of a new channel to the completion of information source decoding of the first information related to the new channel. In the period, the second information source decoding unit is selected to output the second information of the low bit rate corresponding to the first information related to the new channel, and after the elapse of the period, the first information source decoding unit Since the first information related to the new channel is selected and zapping is applicable, it is possible to provide zapping applicable to a live broadcast program.

  Furthermore, the receiving device of the present invention is configured to synchronize the second information output by the information selection output unit in the period and the first information output by the information selection output unit after the period has elapsed. It has the composition provided with.

  With this configuration, the receiving device of the present invention can output the received first information and second information in synchronization. Therefore, when switching from the program based on the second information to the program based on the first information, The program can be viewed without giving a sense of incongruity.

  The present invention can provide a transmitting device and a receiving device that have the effect of being able to provide zapping applicable to a live broadcast program.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. An example in which the transmission device and the reception device of the present invention are applied to a broadcasting system that provides a program on three channels will be described.

(First embodiment)
First, the configuration of the broadcasting system according to the first embodiment of the present invention will be described.

  As shown in FIG. 1, a broadcasting system 10 according to the present embodiment includes encoders 11 to 13 that encode data such as video, audio, text, and still images (hereinafter referred to as “video data”) with information source coding. , A transmission device 100 that transmits a stream including information source-encoded video and other data to the IP network 15, a reception device 200 that receives the stream, and a display device 14 that displays the video and the like. Here, the reason why the IP network 15 is taken as a transmission path is to show an example of a system configuration in the case where it is necessary to compensate for uncertainty in the transmission path by allowing a delay, and the present invention relates to this. It is not limited to. Further, the video data such as information source encoded corresponds to the first information described in the claims.

  Each of the encoders 11 to 13 receives video and other data, and encodes and multiplexes information source codes at a predetermined bit rate. For example, input video data and the like are information source encoded and multiplexed into data in a transstream format (hereinafter referred to as “TS”) conforming to the MPEG (Moving Picture Expert TS Group) -2 standard. The TS thus output is output to the transmitting apparatus 100.

  The display device 14 includes, for example, a video processing circuit, a liquid crystal display, an audio amplification circuit, a speaker, and the like, and reproduces data such as video included in the TS received by the reception device 200 and provides the video and the like to the viewer. It has become.

  Next, the configuration of the transmission device 100 will be described.

  As illustrated in FIG. 2, the transmission apparatus 100 includes a first transmission line encoding unit 110, a second transmission line encoding unit 120, and a third transmission line encoding unit that perform transmission line encoding on data such as video included in the multiplexed TS. A transmission path encoding unit 130, a zapping data generation unit 140 that generates a TS provided on a specific channel, and a communication unit 160 that communicates with the IP network 15 are provided.

  It is assumed that the transmission apparatus 100 transmits TS output from the encoders 11 to 13 to the IP network 15 as program data of the first, second, and third channels. Hereinafter, for example, the program data of the first channel is represented as 1ch program data. The first to third channels and the specific channel are associated with, for example, an address and a port number of the receiving device 200. In the present embodiment, the specific channel is described as the fourth channel. The transmission apparatus 100 includes, for example, a CPU (Central Processing Unit), a ROM (Read-Only Memory), a RAM (Random-Access Memory), and the like, and is operated by a predetermined program.

  The first transmission line encoding unit 110 includes a reception buffer 111 that temporarily stores received 1ch program data, an FEC encoding unit 112 that performs FEC encoding processing of the 1ch program data, and an interleave processing unit that performs interleaving processing. 113, a packetizing unit 114 that packetizes 1ch program data, and a transmission buffer 115 that temporarily stores the packetized 1ch program data.

  The reception buffer 111 temporarily stores the 1ch program data that has arrived at the first transmission path encoding unit 110 in the order of arrival, and sequentially outputs them to the FEC encoding unit 112.

  The FEC encoding unit 112 performs FEC encoding of 1ch program data using, for example, Reed-Solomon code. Even if a part of the packet including the 1ch program data packetized by the packetizing unit 114 (hereinafter referred to as “1ch program packet”) is lost after transmission by this FEC encoding, the receiving apparatus 200 performs error correction processing. Can be recovered.

  The interleave processing unit 113 executes an interleaving process for rearranging the data arrangement order to a predetermined order in order to increase the error correction capability in the receiving apparatus 200.

  The packetization unit 114 performs packetization processing based on, for example, UDP / IP (User Datagram Protocol / Internet Protocol).

  The transmission buffer 115 temporarily stores the 1ch program packet generated by the packetizing unit 114 and sequentially outputs it to the communication unit 160.

  Note that the configurations of the second transmission path encoding unit 120 and the third transmission path encoding unit 130 are the same as those of the first transmission path encoding unit 110, and therefore, codes corresponding to the first transmission path encoding unit 110 are attached. The description is omitted. However, the 2nd transmission line encoding part 120 and the 3rd transmission line encoding part 130 carry out transmission line encoding of 2ch program data and 3ch program data, respectively. In addition, the 1st transmission line encoding part 110, the 2nd transmission line encoding part 120, and the 3rd transmission line encoding part 130 comprise the 1st information input means of this invention.

  The zapping data generation unit 140 includes transcoding units 141, 142, and 143 that respectively convert 1ch to 3ch program data into low bit rate program data (hereinafter referred to as "zapping data"), and multiplexing that multiplexes the zapping data. Unit 144 and a fourth transmission line encoding unit 150 that performs transmission line encoding on the multiplexed zapping data. The zapping data converted to the low bit rate corresponds to the second information described in the claims.

  The transcoding unit 141 receives 1ch program data encoded at a predetermined bit rate in the encoder 11 (see FIG. 1), converts the data to a bit rate lower than the bit rate, and converts the 1ch program zapping data ( This is hereinafter referred to as “1ch zapping data”).

  Specifically, when the transcoding unit 141 targets video data, for example, an MPEG-2 Video MP @ HL signal is transmitted to the ITU-T recommendation H.264. By transcoding to the bit rate indicated by the H.264 baseline profile (Baseline Profile), the bit rate is converted to about 1/100 of the original bit rate. Here, the MP @ HL (main profile at high level) signal is a video signal intended for the HDTV (high definition television) class. Transcoding technology is a technology for converting encoded data into a predetermined format without decoding, and the processing speed can be increased compared to the case where encoded data is once decoded and converted, It has the characteristic that there is little degradation of an image | video.

  Similar to the transcoding unit 141, the transcoding unit 142 and the transcoding unit 143 output 2ch zapping data and 3ch zapping data, respectively. Note that the transcoding units 141 to 143 constitute the bit rate conversion means of the present invention.

  The multiplexing unit 144 receives 1 to 3 ch zapping data and multiplexes them into one TS. The multiplexed 1 to 3 ch zapping data output from the multiplexing unit 144 corresponds to the multiplexed second information described in the claims. The multiplexing unit 144 constitutes a multiplexing unit of the present invention.

  In the present embodiment, since the number of channels is assumed to be 3, the multiplexing unit 144 is multiplexed to one TS. However, the present invention is not limited to this. It is good also as a structure multiplexed to several TS. Specifically, if the number of channels is 100, the zapping data corresponding to 100 channels of program data is divided into two groups of 50, for example, and the two groups of zapping data are multiplexed into two TSs, respectively. The multiplexing unit 144 can be configured to do so.

  In addition, transmitting apparatus 100 according to the present embodiment includes transcoding sections 141 to 143, and multiplexing section 144 is configured to input 1 to 3ch zapping data from transcoding sections 141 to 143, respectively. The invention is not limited to this. For example, an encoder that transcodes 1 to 3 ch program data may be prepared outside, and the multiplexing unit 144 may input 1 to 3 ch zapping data from the encoder. In this case, the multiplexing unit 144 constitutes the second information input unit of the present invention.

  The fourth transmission path encoding unit 150 receives the reception buffer 151 that temporarily stores the multiplexed zapping data, the FEC encoding unit 152 that performs the FEC encoding process of the zapping data, and the interleaving process of the zapping data The interleave processing unit 153 includes a packetizing unit 154 that packetizes zapping data, and a transmission buffer 155 that temporarily stores the packetized zapping data.

  The reception buffer 151 temporarily stores the zapping data that has been multiplexed and arrived at the fourth transmission path encoding unit 150 in the order of arrival, and sequentially outputs the zapping data to the FEC encoding unit 152.

  The FEC encoding unit 152 performs FEC encoding of zapping data using, for example, Reed-Solomon code. Even if a part of the packet including the zapping data packetized by the packetizing unit 154 (hereinafter referred to as “zapping data packet”) disappears after transmission by this FEC encoding, the receiving apparatus 200 performs error correction processing. Can be recovered.

  The interleave processing unit 153 performs an interleaving process for rearranging the data arrangement order to a predetermined order in order to improve the error correction capability in the receiving apparatus 200.

  The packetizing unit 154 divides the interleaved zapping data and performs packetization processing based on, for example, UDP / IP.

  The transmission buffer 155 temporarily stores the zapping packet generated by the packetizing unit 154 and sequentially outputs it to the communication unit 160.

  The communication unit 160 transmits the 1-3 channel program packets encoded by the first transmission path encoding unit 110, the second transmission path encoding unit 120, and the third transmission path encoding unit 130 to the transmission buffer 115, The data are sequentially read from 125 and 135 and transmitted to the IP network 15 as TS of the programs of the first, second and third channels. Note that the communication unit 160 constitutes the transmission means of the present invention.

  Further, the communication unit 160 sequentially reads the zapping data packets encoded by the fourth transmission line encoding unit 150 from the transmission buffer 155, and determines the predetermined specific channel, which is the fourth channel in the present embodiment. The program TS is sent to the IP network 15.

  Further, the communication unit 160 describes information relating the program data and the zapping data by using, for example, a table as shown in FIG. 3 or the program data corresponding to the zapping data in the zapping data by using a link descriptor. Thus, the data is transmitted to the receiving device 200.

  FIG. 3 shows an example of a table representing a relationship between (original_network_id, ts_id, service_id) of program data to be transmitted and (original_network_id, ts_id, service_id) of zapping data. Here, “original_network_id” indicates an identifier unique to the network. “Ts_id” indicates an identifier for identifying the TS, and “service_id” indicates an identifier assigned to each service in order to identify each service in the network.

  Further, for example, STIB-B. Of ARIB (Association of Radio Industries and Businesses). Assuming that the system operates in accordance with SI (Service Information) specified in 10, it is preferable to specify program data to be transmitted by the communication unit 160 as an alternative service in this specification and describe destinations (original_network_id, ts_id, service_id). . The channel on which the program data and zapping data transmitted by the communication unit 160 are provided is transmitted by extending the data on the relationship between the program data and the zapping data, including channel information such as an IP address and a port number. Alternatively, (original_network_id, ts_id, service_id) and channel information on which the information is transmitted may be separately transmitted in, for example, the NIT (Network Information Table) format. Note that the channel information may be acquired by scanning the predetermined channel range on the receiving device 200 side.

  Next, the configuration of receiving apparatus 200 will be described.

  As shown in FIG. 4, the receiving device 200 selects a communication unit 201 that communicates with the IP network 15, a channel selection unit 202 that selects a channel to be received, and a control unit 203 that controls the operation of the entire device. A first transmission path decoding unit 210 that performs transmission path decoding of received program data, a second transmission path decoding section 220 that always decodes zapping data that is always received, and transmission path decoded program data Is output from one of the first decoder 204 and the second decoder 205, the second decoder 205 that decodes the zapping data subjected to transmission path decoding, and the first decoder 204. And a switching unit 206 that selects and outputs the data. Note that the receiving device 200 includes, for example, a CPU, a ROM, a RAM, and the like, and is operated by a predetermined program.

  The communication unit 201 includes a network interface, communicates with the IP network 15, and receives program data packets related to the channel selected by the channel selection unit 202. Note that the communication unit 201 constitutes the receiving means of the present invention.

  Further, the communication unit 201 is configured to always receive a zapping data packet transmitted from the transmission device 100 through a specific channel regardless of the channel selected by the channel selection unit 202.

  The channel selection unit 202 includes a channel key for selecting a channel and a signal generation circuit that generates a channel signal corresponding to the channel key, and outputs a channel signal corresponding to the channel selected by the viewer to the control unit 203. It is supposed to be. Note that the program data of the channel selected by the channel selection unit 202 corresponds to the selection first information described in the claims. The channel selection unit 202 constitutes channel selection means of the present invention.

  Based on the channel signal from the channel selection unit 202, the control unit 203 outputs a control signal to each part of the apparatus and controls the operation of each part. This control signal is indicated by a dashed arrow starting from the control unit 203 in FIG.

  The first transmission path decoding unit 210 performs an input buffer 211 that temporarily stores a packet received by the communication unit 201 on the selected channel, a packet processing unit 212 that performs predetermined packet processing, and a deinterleave process. A deinterleave processing unit 213, an FEC recovery unit 214 that recovers lost packets, and an output buffer 215 that temporarily stores program data are provided. The first transmission path decoding unit 210 constitutes the first transmission path decoding means of the present invention.

  The input buffer 211 temporarily stores, for example, a packet based on UDP / IP. The packet processing unit 212 performs processing for extracting program data from a packet based on, for example, UDP / IP. The deinterleave processing unit 213 rearranges and outputs the program data according to a predetermined rule. When a packet loss occurs during transmission, the FEC recovery unit 214 performs error correction processing by, for example, Reed-Solomon decoding, and recovers lost data. The output buffer 215 is composed of, for example, a FIFO (First In First Out) type memory, and temporarily stores program data that has been subjected to transmission path decoding, and outputs the program data from the first stored data first. .

  The second transmission path decoding unit 220 has the same configuration as that of the first transmission path decoding unit 210, so the description of the configuration is omitted. However, while the first transmission path decoding unit 210 performs transmission path decoding of the program data of the selected channel, the second transmission path decoding unit 220 does not always receive zapping data. The transmission path is always decoded regardless of the selected channel. The second transmission path decoding unit 220 constitutes the second transmission path decoding means of the present invention.

  FIG. 4 shows the configuration of the second transmission path decoding unit 220 assuming that zapping data is multiplexed into one TS. However, zapping data is multiplexed into a plurality of TSs. In the case of being present, all of the plurality of TSs are always received to perform transmission path decoding.

  The first decoder 204 is configured to perform information source decoding on the program data that has been channel-decoded by the first channel decoding unit 210. The second decoder 205 is configured to perform information source decoding on the zapping data subjected to the transmission path decoding by the second transmission path decoding unit 220. The first decoder 204 and the second decoder 205 constitute first information source decoding means and second information source decoding means of the present invention, respectively.

  Based on the channel selection state by the channel selection unit 202, the switching unit 206 receives either the program data decoded by the first decoder 204 or the zapping data decoded by the second decoder 205. Select and output. Note that the switching unit 206 constitutes an information selection output unit of the present invention.

  Specifically, when the switching unit 206 selects the first decoder 204 and the second channel is selected by the channel selection unit 202 in a state where a program of the first channel is provided to the viewer, for example, the switching unit 206 In the period from the selection of the second channel to the completion of the information source decoding of the 2ch program data (hereinafter referred to as “waiting period”) 206, the second decoder 205 is selected to correspond to the 2ch program data. 2ch zapping data is output, and after the standby period has elapsed, that is, when the 2ch program data decoded from the information source is ready to be output from the first decoder 204, the first decoder 204 is selected and the 2ch program data is selected. Is output.

  Note that the zapping data subjected to transmission path decoding by the second transmission path decoding section 220 is discarded by the output buffer 225 or the second decoder 205 during the period in which the switching section 206 selects the first decoder 204. It has become.

  Next, the operation of the broadcast system 10 according to the present embodiment will be described.

  First, operations of the encoders 11 to 13 and the transmission apparatus 100 will be described with reference to FIGS. 1 and 2.

  First, as shown in FIG. 1, video and other data constituting 1 to 3 ch program data is input to encoders 11 to 13, respectively. Next, the video data such as video data is encoded and multiplexed at a predetermined bit rate by the encoders 11 to 13 and output to the transmission apparatus 100 as a TS.

  Next, as shown in FIG. 2, the 1 to 3 ch program data input to the transmission device 100 are respectively converted into the first transmission line encoding unit 110, the second transmission line encoding unit 120, and the third transmission line encoding. The signal is input to unit 130, subjected to transmission path encoding, and output to communication unit 160.

  The 1 to 3 ch program data input to the transmission apparatus 100 is also input to the zapping data generation unit 140 in parallel, and converted into 1 to 3 ch zapping data at a low bit rate by the transcoding units 141 to 143. . Subsequently, 1 to 3 ch zapping data is multiplexed into one TS by the multiplexing unit 144, encoded by the fourth transmission path encoding unit 150, and output to the communication unit 160.

  Then, the communication unit 160 outputs the encoded 1 to 3 ch program data and the multiplexed and decoded 1 to 3 ch zapping data as a TS directed to a predetermined address or port number of the receiving apparatus 200. .

  Next, the operation of the receiving apparatus 200 will be described using FIG. 4 and FIG.

  First, after the power is turned on (step S11), the program data of the selected channel is received by the communication unit 201 and output to the first transmission path decoding unit 210 (step S12). Here, the selected channel is, for example, a default channel or a channel when the power is turned off last time, and the following description will be made assuming that the first channel is selected.

  Next, the control unit 203 determines whether or not the 1-channel program data that has been subjected to transmission path decoding can be output from the first transmission path decoding unit 210 (step S13).

  In step S13, if it is not determined that the transmission channel decoded 1ch program data can be output, the process returns to step S12. If it is determined that the transmission channel decoded 1ch program data can be output, The 1ch program data is information source decoded by the 1 decoder 204 (step S14).

  Next, the first decoder 204 is selected by the switching unit 206, and the 1ch program data decoded from the information source is output to the display device 14 (see FIG. 1) (step S15). As a result, the video and audio of the 1ch program are reproduced by the display device 14 and provided to the viewer.

  Subsequently, the control unit 203 determines whether or not the channel is switched by the channel selection unit 202 (step S16).

  If it is not determined in step S16 that the channel has been switched, the process returns to step S14. If it is determined that the channel has been switched, the control unit 203 resets the first transmission path decoding unit 210 (step S14). S17), the process proceeds to step S19 described later. The channel after switching will be described below as the second channel.

  On the other hand, in parallel with step S12, after the power is turned on, regardless of the selected channel, 1 to 3 ch zapping data is received by the communication unit 201 and output to the second transmission path decoding unit 220 (step S18). ).

  Next, the control unit 203 determines whether or not the 1 to 3 ch zapping data subjected to transmission path decoding from the second transmission path decoding unit 220 can be output (step S19).

  If it is not determined in step S19 that the transmission path decoded 1 to 3ch zapping data can be output, the process returns to step S18. Here, the second transmission line decoding unit 220 is configured to always decode the 1 to 3 ch zapping data that is always received, so that the process returns from step S19 to step S18 from several seconds after power-on to several dozens. The period is limited to about a second.

  On the other hand, if it is determined in step S19 that the transmission line decoded 1 to 3ch zapping data can be output, the control unit 203 determines whether or not the first transmission line decoding unit 210 is in a reset state. (Step S20). That is, it is determined whether or not channel switching has been performed.

  If the first transmission path decoding unit 210 is not determined to be in the reset state in step S20, that is, if the channel is not switched, the process proceeds to step S16. On the other hand, when the first transmission path decoding unit 210 is determined to be in the reset state, that is, when the channel is switched, the process proceeds to the program switching process after step S21.

  In the program switching process, first, 2ch program data is received by the communication unit 201 and output to the first transmission path decoding unit 210 (step S21), and transmitted from the first transmission path decoding unit 210 by the control unit 203. It is determined whether or not the channel-decoded 2ch program data can be output (step S22).

  In step S22, if it is not determined that the transmission channel decoded 2ch program data can be output, the process returns to the program switching process after step S21.

  In parallel with step S21, 2ch zapping data is information source decoded by the second decoder 205 (step S23).

  Subsequently, the second decoder 205 is selected by the switching unit 206, and the 2ch zapping data subjected to information source decoding is output to the display device 14 (step S24), and the process proceeds to step S22. As a result of outputting the 2ch zapping data to the display device 14, a 2ch program based on low-rate video, audio data, etc. is reproduced and provided to the viewer.

  If it is determined in step S22 that the channel-decoded 2ch program data can be output, the process proceeds to step S14, and the first decoder 204 decodes the 2ch program data (step S14). Is output to the display device 14 (step S15).

  As described above, according to broadcasting system 10 according to the present embodiment, transmitting apparatus 100 transmits a plurality of program data through different channels, and each program data is transmitted at a low bit on a specific channel different from these channels. The zapping data converted into the rate is transmitted, and the receiving apparatus 200 constantly receives the zapping data, and in the standby period until a new channel is selected and the program data of the channel can be reproduced, Since the corresponding zapping data is output to the display device 14, zapping applicable to a live broadcast program can be provided.

  In the above-described embodiment, the receiving apparatus 200 has been described by taking as an example the configuration including the first decoder 204 and the second decoder 205 as information source decoding means, but the present invention is limited to this. For example, the receiving apparatus 200 may not include the information source decoding unit, and the switching unit 206 may select one of the first transmission path decoding unit 210 and the second transmission path decoding unit 220. .

(Second Embodiment)
First, the configuration of the broadcasting system according to the second embodiment of the present invention will be described. However, the broadcasting system according to the present embodiment is obtained by changing the receiving device 200 (see FIG. 4) of the broadcasting system 10 (see FIG. 1) according to the first embodiment to the receiving device 300 shown in FIG. Only the configuration of the receiving apparatus 300 will be described, and components other than the receiving apparatus 300 will be described with the same reference numerals as those in the first embodiment.

  As shown in FIG. 6, the receiving device 300 includes a communication unit 301 that communicates with the IP network 15, a channel selection unit 302 that selects a channel to be received, a control unit 303 that controls the operation of the entire device, and a received program. A first transmission line decoding unit 310 for decoding the transmission line; a second transmission line decoding unit 320 for decoding the received zapping data; and information source decoding of the transmission line decoded program data. The first decoder 304, the second decoder 305 that decodes the zapping data subjected to the transmission path decoding, and the data output from either the first decoder 304 or the second decoder 305 are selected and output. And a delay circuit 307 that delays program data. Note that the receiving apparatus 300 includes, for example, a CPU, a ROM, a RAM, and the like, and is operated by a predetermined program.

  The delay circuit 307 receives the program data of the selected channel from the communication unit 301, delays it for a predetermined time, and outputs it to the first transmission path decoding unit 310. Note that the delay circuit 307 constitutes the synchronizing means of the present invention.

  In the transmitting apparatus 100 (see FIG. 2) according to the first embodiment, zapping data corresponding to program data is generated. Since zapping data is transcoded and multiplexed, program data is used. Will be transmitted later. Assuming that the average delay time is D, in the receiving apparatus 200 (see FIG. 4) according to the first embodiment, when switching from zapping data to program data, an image or the like shifted by time D is displayed on the display apparatus 14. As a result, the viewer may feel uncomfortable when switching programs.

  In the broadcast system according to the present embodiment, the delay circuit 307 is provided in the receiving apparatus 300, thereby eliminating the uncomfortable feeling at the time of switching.

  Specifically, as shown in FIG. 7, first, in transmission apparatus 100, a range in which an STD (System Target Decoder) buffer used in MPEG-2 decoding is not broken for frames corresponding to program data and zapping data. At the same time, the same PTS (Presentation Time Stamp) is attached, and the PCR (Program Clock Reference) included in the adaptation field of the TS packet is synchronized by offsetting the zapping data by the time D.

  Next, in receiving apparatus 300 (see FIG. 6) according to the present embodiment, the delay time is adjusted by delay circuit 307 so that the PCR of the selected program data is synchronized with the zapping data. Yes. As a result, the time when the selected program data is input to the first decoder 304 and the time when the zapping data is input to the second decoder 305 substantially coincide, and the switching unit 306 switches from the zapping data to the program data. In addition, the frame shift between the two can be suppressed (see FIG. 7).

  In broadcasting using the IP network 15, the delay time may be different when the TS packet of each program data passes through a different route for each channel. However, the delay circuit 307 includes a time relationship including the delay time. It is good also as a structure which adjusts. Further, in order to synchronize each program data and zapping data on the transmission apparatus 100 side, a configuration may be provided in which delay means for delaying each program data by a predetermined time from the zapping data may be provided.

  As described above, according to the broadcasting system according to the present embodiment, receiving apparatus 300 is configured to include delay circuit 307 that synchronizes selected program data and zapping data, so that it can be viewed when switching between programs. Thus, zapping that can be applied to a live broadcast program can be provided without causing the viewer to feel uncomfortable.

(Third embodiment)
First, the configuration of the broadcasting system according to the third embodiment of the present invention will be described. In the present embodiment, an example in which a program using IP multicast communication is provided to a plurality of users via a PON (Passive Optical Network) will be described.

  As shown in FIG. 8, the broadcasting system 30 according to the present embodiment includes an encoder 31 to 33 that encodes video source data and the like, and a stream including video source data encoded by the information source to the IP network 35. A transmission apparatus 400 for transmission, a multicast router 34 for performing routing processing in multicast communication, and a PON system 500 are provided.

  The PON system 500 includes an OLT (Optical Line Terminal) 510 that supplies program data, an optical fiber 520 that transmits the program data, an optical coupler 530 that branches the program data, and a plurality of ONUs (Optical Network) that receive the program data. Unit) 540 (540a, 540b...) And a display device 550 (550a, 550b...) Connected to the ONU 540.

  Here, transmitting apparatus 400 according to the present embodiment is configured similarly to transmitting apparatus 100 (see FIG. 2) according to the first embodiment. Further, each of the plurality of ONUs 540 according to the present embodiment is configured by the receiving apparatus 200 (see FIG. 4) according to the first embodiment. The encoders 31 to 33 correspond to the encoders 11 to 13 according to the first embodiment. The display device 550 corresponds to the display device 14 according to the first embodiment. Therefore, the description which overlaps with the description of the first embodiment is omitted.

  The multicast router 34 is configured to manage a multicast group and relay program data by sending an IGMP (Internet Group Management Protocol) query message, for example.

  In FIG. 8, for example, it is assumed that the user A operates the ONU 540a to switch the channel to change from the program P to the program Q. Channel switching is equivalent to changing a participating multicast group in IGMP. When the channel is switched, a signal indicating group leaving is transmitted from the ONU 540a used by the user A to the multicast router 34 as a signal for ending the viewing of the program P that has been viewed before the switching. The

  First, problems of the conventional PON system will be described. However, for convenience, the same reference numerals as those shown in FIG. 8 are used.

  In the conventional PON system, when a signal indicating group leaving is transmitted from the ONU 540a to the multicast router 34, the multicast router 34 determines whether there is a user of another program P in the same group that the user A is about to leave. Confirmation process is performed. Therefore, because of this confirmation processing, the multicast router 34 delays stopping transmission of data of the program P to the ONU 540a, and as a result, there is a possibility that it takes time to switch programs in the ONU 540a.

  In the conventional PON system, the multicast router 34 can also perform group participation of the next program Q without performing the group leaving process. In this case, the original program is switched after switching the channel. Until distribution of P stops, two TSs including data of program P and program Q are distributed to ONU 540a. That is, assuming that the information rate per program is R and the number of users of the ONU 540 sharing the access system is N, the conventional PON system consumes a maximum bandwidth of 2 × R × N.

  On the other hand, in the broadcasting system 30 according to the present embodiment, zapping data converted to a low rate is used at the time of channel switching. Therefore, if the band of this zapping data is α, the necessary band is about R × N + α at the maximum. And the required maximum rate can be reduced. Since the original program data encoded at a low rate is used, α can be suppressed to about R to 2R. Moreover, in the broadcasting system 30 according to the present embodiment, the above-described confirmation process is not necessary, and therefore zapping can be provided to the user at a speed higher than that of the conventional system.

  As described above, according to the broadcast system 30 according to the present embodiment, in the PON system, the ONU 540 is configured to use the zapping data converted to the low rate at the time of channel switching. The required maximum rate can be reduced as compared with the conventional one, and zapping applicable to a live broadcast program can be provided.

  As described above, the transmission device and the reception device according to the present invention have an effect that zapping that can be applied to a live broadcast program can be provided, and moving image and audio data can be transmitted through a plurality of channels. It is useful as a transmission apparatus, a reception apparatus, and the like that perform high-speed zapping processing when streaming transmission is performed and channels are switched.

The block diagram of the broadcasting system which concerns on the 1st Embodiment of this invention. The block diagram of the transmitter which concerns on the 1st Embodiment of this invention The figure which shows an example of the table which shows the relationship between the program data and the zapping data which the transmitter which concerns on the 1st Embodiment of this invention transmits The block diagram of the receiver which concerns on the 1st Embodiment of this invention The flowchart of each step of the receiver which concerns on the 1st Embodiment of this invention The block diagram of the receiver which concerns on the 2nd Embodiment of this invention Operation explanatory diagram of the broadcasting system according to the second embodiment of the present invention The block diagram of the broadcasting system which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 30 Broadcasting system 11-13, 31-33 Encoder 14,550 (550a, 550b) Display apparatus 15,35 IP network 34 Multicast router 100,400 Transmission apparatus 110 1st transmission-line encoding part (1st information input means) )
111, 121, 131, 151 Receive buffer 112, 122, 132, 152 FEC encoder 113, 123, 133, 153 Interleave processor 114, 124, 134, 154 Packetizer 115, 125, 135, 155 Transmit buffer 120 Second transmission line encoding unit (first information input means)
130 3rd transmission line encoding part (1st information input means)
140 Zapping data generation unit 141-143 Transcoding unit (bit rate conversion means)
144 Multiplexing unit (second information input means, multiplexing means)
150 4th transmission line encoding part 160 Communication part (transmission means)
200, 300 Receiving device 201, 301 Communication unit (receiving means)
202, 302 Channel selection section (channel selection means)
203, 303 Control unit 204, 304 First decoder (first information source decoding means)
205, 305 Second decoder (second information source decoding means)
206, 306 switching unit (information selection output means)
210, 310 First transmission path decoding unit (first transmission path decoding means)
211, 221 Input buffer 212, 222 Packet processing unit 213, 223 Deinterleave processing unit 214, 224 FEC recovery unit 215, 225 Output buffer 220, 320 Second transmission path decoding unit (second transmission path decoding means)
307 delay circuit (synchronization means)
500 PON system 510 OLT
520 Optical fiber 530 Optical coupler 540 (540a, 540b) ONU (receiving device)

Claims (6)

First information input means for inputting a plurality of pieces of first information encoded at a predetermined bit rate, and a plurality of second information obtained by converting the plurality of pieces of first information to a bit rate lower than the bit rate. A second information input means for inputting information; a multiplexing means for multiplexing the plurality of second information and outputting the multiplexed second information; and transmitting the plurality of first information through mutually different channels. A transmission apparatus comprising: transmission means for transmitting the second information on a specific channel different from the channel. And a bit rate conversion unit that inputs the plurality of first information, converts the plurality of first information to a bit rate lower than the bit rate, and outputs the plurality of second information. The transmission device according to claim 1. The transmission apparatus according to claim 1, further comprising a delay unit that delays a time at which the plurality of pieces of first information are transmitted by the transmission unit by a predetermined time. Channel selection means for selecting a predetermined channel for receiving one of a plurality of pieces of first information encoded at a predetermined bit rate, first selection information on the selected channel, and Receiving means for receiving a plurality of second information transmitted on a specific channel regardless of the channel, a first transmission path decoding means for decoding the selected first information, and the received plurality of received first information 2 Information for selecting and outputting information output from either one of the second transmission path decoding means for decoding the transmission path, and the first transmission path decoding means and the second transmission path decoding means. Selection output means,
The plurality of second information is obtained by converting the plurality of first information to a bit rate lower than the bit rate, respectively.
The information selection output means is a period from when the new channel is selected until the transmission line decoding of the first information related to the new channel is completed when a new channel is selected by the channel selection means. The second transmission path decoding means is selected to output second information at a low bit rate corresponding to the first information related to the new channel, and after the elapse of the period, the first transmission path decoding The receiving apparatus is characterized in that the first information relating to the new channel is output by selecting the converting means. Channel selection means for selecting a predetermined channel for receiving one of a plurality of pieces of first information encoded at a predetermined bit rate, first selection information on the selected channel, and Receiving means for receiving a plurality of second information transmitted on a specific channel regardless of the channel, a first transmission path decoding means for decoding the selected first information, and the received plurality of received first information 2) a second transmission path decoding means for performing transmission path decoding, a first information source decoding means for decoding the first information subjected to transmission path decoding, and the plurality of transmission path decoded pieces. The second information source decoding means for decoding the second information of the information source, and the information output from any one of the first information source decoding means and the second information source decoding means is selected and output Information selection and output means ,
The plurality of second information is obtained by converting the plurality of first information to a bit rate lower than the bit rate, respectively.
The information selection output means is a period from when the new channel is selected until the information source decoding of the first information related to the new channel is completed when a new channel is selected by the channel selection means. The second information source decoding means is selected to output second information at a low bit rate corresponding to the first information related to the new channel, and after the period, the first information source decoding The receiving apparatus is characterized in that the first information relating to the new channel is output by selecting the converting means. And a synchronization unit configured to synchronize the second information output by the information selection output unit during the period and the first information output by the information selection output unit after the elapse of the period. The receiving device according to claim 4 or 5.

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