JP6848797B2 - Broadcast retransmission device, broadcast receiver, broadcast retransmission method, broadcast reception method, broadcast retransmission program and broadcast reception program - Google Patents

Description

The present invention relates to a broadcast retransmission device, a broadcast reception device, a broadcast retransmission method, a broadcast reception method, a broadcast retransmission program, and a broadcast reception program.

Conventionally, a technique for transmitting content using an MMTP (MPEG Media Transport Protocol) packet has been developed.

For example, in Non-Patent Document 1 (Association of Radio Industries and Businesses, "Media Transport System by MMT in Digital Broadcasting ARIB STD-B60 1.9 Edition", March 24, 2017), broadcasting using the MMT system. The system is disclosed.

In this broadcasting system, an MMT packet containing program information such as audio information and video information is stored in the payload of the IP packet. The IP packet is stored in the payload of the TLV (Type Length Value) packet.

Association of Radio Industries and Businesses, "Media Transport Method by MMT in Digital Broadcasting ARIB STD-B60 1.9 Edition", March 24, 2017 International Telecommunication Union Radiocommunication Sector, "Recommunication ITU-R BT.1869", March 2010, [online], [Search on August 29, 2017], Internet <URL: http: // www. itu. int / dms_pubrec / itu-r / rec / bt / R-REC-BT. 1869-0-201003-I! !! PDF-E. pdf> "JCTEA STD-002-6.0 Digital Cable Television Broadcasting Multiplexer", Japan CATV Technology Association

For example, in the case of performing an IP retransmission service for transmitting an advanced broadband satellite digital broadcast to a subscriber's home via an IP (Internet Protocol) TV transmission network, a broadcast wave including an MMT packet is received and the received MMT packet is subscribed. A configuration is conceivable in which the data is retransmitted to the in-house device at the person's home. A technique for efficiently performing such retransmission is desired.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to efficiently transmit program information in a configuration in which a broadcast wave including program information is received and retransmitted to another device. It is to provide a broadcast retransmission device, a broadcast reception device, a broadcast retransmission method, a broadcast reception method, a broadcast retransmission program, and a broadcast reception program that can be performed.

(1) In order to solve the above problems, the broadcast retransmission device according to a certain aspect of the present invention is a stream containing a null packet for adjusting a transmission rate, which is generated by demolishing a broadcast wave according to the MMT method. The acquisition unit that acquires the null packet, the deletion unit that deletes the null packet from the stream acquired by the acquisition unit, and the stream from which the null packet is deleted by the deletion unit are transmitted to another device via a communication line. It is provided with a transmission unit.

(5) In order to solve the above problems, the broadcast retransmission device according to another aspect of the present invention transmits a variable size packet including program information generated by demolishing a broadcast wave according to the MMT method. An acquisition unit for acquiring a stream including the variable packet, a divided storage unit for creating a plurality of fixed packets having a predetermined size including data obtained by dividing the variable packet, and each of the fixed packets created by the divided storage unit. It includes a transmission unit that transmits the stream included in place of the variable packet to another device via a communication line.

(6) In order to solve the above problems, in the broadcast receiving device according to a certain aspect of the present invention, null packets for adjusting the transmission rate are deleted from the stream generated by demolating the broadcast wave according to the MMT method. It is a stream, and a variable size packet containing program information is a plurality of fixed packets having a predetermined size, each containing divided data, and time adjustment information for performing time adjustment between devices. A receiver that receives a stream containing the fixed packet to which transmission time information is added, which indicates a count value calibrated in use as a transmission timing, from another device, a clock generator that generates a reference clock, and the reference clock. It includes a counter that updates the count value based on the above, and a synchronization processing unit that controls at least one of the clock generation unit and the counter by using the transmission time information added to the fixed packet.

(7) In order to solve the above problems, the broadcast retransmission method according to a certain aspect of the present invention is a broadcast retransmission method in a broadcast retransmission device, and is generated by demodulating a broadcast wave according to the MMT method. , A step of acquiring a stream containing a null packet for adjusting a transmission rate, a step of deleting the null packet from the acquired stream, and a step of deleting the null packet from the stream to another device via a communication line. Includes steps to send to.

(8) In order to solve the above problems, the broadcast retransmission method according to another aspect of the present invention is a broadcast retransmission method in a broadcast retransmission device, and is generated by demodulating a broadcast wave according to the MMT method. Further, a step of acquiring a stream including a variable size packet containing program information and a plurality of fixed packets having a predetermined size including the divided data of the variable packet included in the acquired stream are created. This includes a step of transmitting the stream including the created fixed packet instead of the variable packet to another device via a communication line.

(9) In order to solve the above problems, the broadcast reception method according to a certain aspect of the present invention includes a clock generator that generates a reference packet and a counter that updates a count value based on the reference clock. A broadcast receiving method in a device, which includes a step of receiving a stream from another device from which a null packet for adjusting a transmission rate has been deleted from a stream generated by demolishing a broadcast wave according to the MMT method. A stream is a plurality of fixed packets having a predetermined size, each of which is a variable size packet containing program information and contains divided data, and is calibrated using time adjustment information for time adjustment between devices. The broadcast receiving method includes the clock generation unit and the clock generation unit using the transmission time information added to the fixed packet, including a fixed packet to which the transmission time information indicating the counted value as the transmission timing is added. Includes steps to control at least one of the counters.

(10) In order to solve the above problems, the broadcast retransmission program according to a certain aspect of the present invention is a broadcast retransmission program used in the broadcast retransmission device, and the computer demodes the broadcast wave according to the MMT method. An acquisition unit that acquires a stream containing null packets for adjusting the transmission rate, a deletion unit that deletes the null packet from the stream acquired by the acquisition unit, and a deletion unit that deletes the null packet. This is a program for functioning as a transmitter that transmits the stream from which null packets have been deleted to another device via a communication line.

(11) In order to solve the above-mentioned problems, the broadcast retransmission program according to another aspect of the present invention is a broadcast retransmission program used in a broadcast retransmission device, and demodies a broadcast wave according to the MMT method by using a computer. Creates a plurality of fixed packets having a predetermined size, each of which includes an acquisition unit for acquiring a stream including variable size packets including program information and data obtained by dividing the variable packets. It is a program for functioning as a divided storage unit and a transmission unit that transmits the stream including each fixed packet created by the divided storage unit in place of the variable packet to another device via a communication line.

(12) In order to solve the above problems, a broadcast reception program according to a certain aspect of the present invention includes a clock generator that generates a reference packet and a counter that updates a count value based on the reference clock. A broadcast reception program used in a device that allows a computer to receive from another device a stream from which null packets for adjusting the transmission rate have been removed from the stream generated by demodating the broadcast wave according to the MMT method. It is a program for functioning as a receiving unit, and the stream is a plurality of fixed packets having a predetermined size, each containing divided data in a variable size packet containing program information, and is used between devices. A fixed packet to which transmission time information is added indicating a count value calibrated using the time adjustment information for time adjustment as a transmission timing is included, and the computer is further subjected to the transmission time information added to the fixed packet. Is a program for functioning as a synchronization processing unit that controls at least one of the clock generation unit and the counter.

The present invention can be realized not only as a broadcast retransmission device provided with such a characteristic processing unit, but also as a system including a broadcast retransmission device. Further, the present invention can be realized as a semiconductor integrated circuit that realizes a part or all of the broadcast retransmission device.

Further, the present invention can be realized not only as a broadcast receiving device provided with such a characteristic processing unit, but also as a system including a broadcast receiving device. Further, the present invention can be realized as a semiconductor integrated circuit that realizes a part or all of a broadcast receiving device.

According to the present invention, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.

FIG. 1 is a diagram showing a configuration of a broadcast retransmission system according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of a protocol stack of data transmitted by broadcast waves in the broadcast retransmission system according to the embodiment of the present invention. FIG. 3 is a diagram showing an example of a TLV packet transmitted by a broadcast wave in the broadcast retransmission system according to the embodiment of the present invention. FIG. 4 is a diagram showing another example of a protocol stack of data transmitted by a broadcast wave. FIG. 5 is a diagram showing an example of a TS packet transmitted by a broadcast wave. FIG. 6 is a diagram showing a configuration of a broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention. FIG. 7 is a diagram showing an example of a TLV packet division method performed in the broadcast retransmission device according to the embodiment of the present invention. FIG. 8 is a diagram showing an example of the TS packet format shown in FIG. 7. FIG. 9 is a diagram showing a configuration of an IP broadcast receiving device in the broadcast retransmission system according to the embodiment of the present invention. FIG. 10 is a flowchart defining an operation procedure when the broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention calibrates the transmission side count value. FIG. 11 is a flowchart defining an operation procedure when the broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention processes a TLV packet. FIG. 12 is a flowchart defining an operation procedure when the broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention creates an IP packet for distribution. FIG. 13 is a flowchart defining an operation procedure when the IP broadcast receiving device in the broadcast retransmission system according to the embodiment of the present invention calibrates the receiving side count value. FIG. 14 is a flowchart defining an operation procedure when the IP broadcast receiving device in the broadcast retransmission system according to the embodiment of the present invention adjusts the oscillation frequency in the VCO.

First, the contents of the embodiments of the present invention will be listed and described.

(1) The broadcast retransmission device according to the embodiment of the present invention includes an acquisition unit that acquires a stream including a null packet for adjusting a transmission rate, which is generated by demodulating a broadcast wave according to the MMT method. It includes a deletion unit that deletes the null packet from the stream acquired by the acquisition unit, and a transmission unit that transmits the stream from which the null packet has been deleted by the deletion unit to another device via a communication line.

In the broadcast wave, for example, a null packet for bit rate adjustment may be inserted in order to fix the transmission rate according to the transmission device of the broadcast wave. As described above, by deleting null packets from the stream, the amount of transmitted data can be reduced as compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet, so that the communication line can be used. Communication traffic can be reduced. As a result, it is possible to suppress transmission delays in program information and fluctuations in transmission time. Therefore, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.

(2) Preferably, the stream further includes a variable size packet containing program information, and the broadcast retransmission device further includes a plurality of variables having a predetermined size, each including divided data of the variable packet. The transmission unit includes the fixed packet for which the null packet is deleted by the deletion unit and each of the fixed packets created by the division storage unit is included in place of the variable packet. Send a stream.

For example, when a variable packet is converted into an IP packet as it is, a jumbo packet having a size larger than that of an MTU (Maximum Transmission Unit) may be generated. With the above configuration, for example, by adjusting the number of fixed packets stored in the payload of the IP packet, it is possible to generate an IP packet having an appropriate size smaller than the MTU. As a result, the IP packet can be transmitted on the Internet without being fragmented, so that the information of the program can be transmitted more efficiently.

(3) More preferably, the broadcast retransmission device further includes an additional unit that adds transmission time information indicating the transmission timing of the fixed packet to the fixed packet.

The transmission rate of the stream from which null packets have been deleted fluctuates. Further, in the communication line, fluctuations in the transmission time of fixed packets and loss, duplication and replacement of fixed packets may occur. Therefore, in other devices, it becomes difficult to manage the buffer based on the amount of received data. With the above configuration, in other devices, it is possible to correctly determine the excess or deficiency of the received data amount based on the transmission time information, so that buffer management can be easily performed.

(4) More preferably, the stream further includes time adjustment information for performing time adjustment between devices, and the broadcast retransmission device further includes a clock generation unit that generates a reference clock and the reference clock. A counter that updates the count value based on the above, and a time synchronization unit that calibrates the count value of the counter by using the time adjustment information included in the stream are provided, and the additional unit includes the count value as the transmission timing. The transmission time information indicating the above is added to the fixed packet.

In this way, by using the time adjustment information included in the broadcast wave that does not cause fluctuations in the transmission time to adjust the time to the counter, the time of the broadcast retransmission device can be set to the time of the broadcast wave transmission device, for example. It can be adjusted more accurately depending on the Coordinated Universal Time. Then, by adding the transmission time information indicating the count value as the transmission timing of the fixed packet to the fixed packet, the other device sets its own time based on the transmission time information, for example, the time of the broadcast retransmission device. It can be adjusted to the world time. Thereby, for example, another device can decode or present the information of the program whose decoding timing and presentation timing are specified by Coordinated Universal Time at an appropriate timing. Further, for example, since the transmission frequency of the transmission time information is often higher than the transmission frequency of the time adjustment information, other devices use the transmission time information that is frequently received even if their own time shifts. , You can correct your time early.

(5) The broadcast retransmission device according to the embodiment of the present invention includes an acquisition unit that acquires a stream including a variable size packet including program information generated by demolishing a broadcast wave according to the MMT method. , A divided storage unit that creates a plurality of fixed packets having a predetermined size, each of which includes divided data, and said that each fixed packet created by the divided storage unit is included in place of the variable packet. It includes a transmitter that transmits a stream to another device via a communication line.

For example, when a variable packet is converted into an IP packet as it is, a jumbo packet having a size larger than that of the MTU may be generated. With the above configuration, for example, by adjusting the number of fixed packets stored in the payload of the IP packet, it is possible to generate an IP packet having an appropriate size smaller than the MTU. As a result, the IP packet can be transmitted without being fragmented on a communication line such as the Internet. Therefore, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.

(6) The broadcast receiving device according to the embodiment of the present invention transmits a stream from another device from which a null packet for adjusting a transmission rate is deleted from a stream generated by demolishing a broadcast wave according to the MMT method. The stream includes a receiving unit for receiving, and the stream is a plurality of fixed packets having a predetermined size, each of which includes divided data in a variable size packet containing program information, for time adjustment between devices. A clock generator that includes a fixed packet with transmission time information that indicates a count value calibrated using the time adjustment information of the above as a transmission timing, and further generates a reference clock, and a count value based on the reference clock. It includes a counter to be updated and a synchronization processing unit that controls at least one of the clock generation unit and the counter by using the transmission time information added to the fixed packet.

In the broadcast wave, for example, a null packet for bit rate adjustment may be inserted in order to fix the transmission rate according to the transmission device of the broadcast wave. As described above, by deleting null packets from the stream, the amount of transmitted data can be reduced as compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet, so that the communication line can be used. Communication traffic can be reduced. As a result, it is possible to suppress transmission delays in program information and fluctuations in transmission time. Therefore, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.
Further, at least one of the clock generator and the counter is used by using the transmission time information indicating the count value calibrated using the time adjustment information included in the broadcast wave in which the transmission time does not fluctuate as the transmission timing. By controlling one of them, the time of the broadcast receiving device can be adjusted more accurately to Coordinated Universal Time. For example, the information of the program whose decoding timing and presentation timing are specified by Coordinated Universal Time can be adjusted at an appropriate timing. It can be decoded and presented. Further, for example, since the transmission frequency of the transmission time information is often higher than the transmission frequency of the time adjustment information, the broadcast receiving device uses the transmission time information that is frequently received even if its own time shifts. , You can correct your time early.

(7) The broadcast retransmission method according to the embodiment of the present invention is a broadcast retransmission method in a broadcast retransmission device, in order to adjust a transmission rate generated by demolishing a broadcast wave according to the MMT method. A step of acquiring a stream containing the null packet of the above, a step of deleting the null packet from the acquired stream, and a step of transmitting the stream from which the null packet has been deleted to another device via a communication line are included. ..

In the broadcast wave, for example, a null packet for bit rate adjustment may be inserted in order to fix the transmission rate according to the transmission device of the broadcast wave. As described above, by deleting null packets from the stream, the amount of transmitted data can be reduced as compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet, so that the communication line can be used. Communication traffic can be reduced. As a result, it is possible to suppress transmission delays in program information and fluctuations in transmission time. Therefore, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.

(8) The broadcast retransmission method according to the embodiment of the present invention is a broadcast retransmission method in a broadcast retransmission device, and is a size including program information generated by demolishing a broadcast wave according to the MMT method. A step of acquiring a stream containing a variable variable packet, a step of creating a plurality of fixed packets having a predetermined size including data obtained by dividing the variable packet included in the acquired stream, and each of the created above. It includes a step of transmitting the stream, which includes a fixed packet in place of the variable packet, to another device via a communication line.

For example, when a variable packet is converted into an IP packet as it is, a jumbo packet having a size larger than that of the MTU may be generated. With the above configuration, for example, by adjusting the number of fixed packets stored in the payload of the IP packet, it is possible to generate an IP packet having an appropriate size smaller than the MTU. As a result, the IP packet can be transmitted without being fragmented on a communication line such as the Internet. Therefore, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.

(9) The broadcast receiving method according to the embodiment of the present invention is a broadcast receiving method in a broadcast receiving device including a clock generation unit that generates a reference clock and a counter that updates a count value based on the reference clock. The stream includes a step of receiving from another device a stream from which null packets for adjusting the transmission rate have been deleted from the stream generated by demolishing a broadcast wave according to the MMT method. The transmission timing of a plurality of fixed packets having a predetermined size, each of which is a variable packet having a variable size including divided data, and calibrated using the time adjustment information for time adjustment between devices. The broadcast receiving method further includes at least one of the clock generator and the counter by using the transmission time information added to the fixed packet, including a fixed packet to which the transmission time information shown as is added. Includes steps to control.

In the broadcast wave, for example, a null packet for bit rate adjustment may be inserted in order to fix the transmission rate according to the transmission device of the broadcast wave. As described above, by deleting null packets from the stream, the amount of transmitted data can be reduced as compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet, so that the communication line can be used. Communication traffic can be reduced. As a result, it is possible to suppress transmission delays in program information and fluctuations in transmission time. Therefore, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.
Further, at least one of the clock generator and the counter is used by using the transmission time information indicating the count value calibrated using the time adjustment information included in the broadcast wave in which the transmission time does not fluctuate as the transmission timing. By controlling one of them, the time of the broadcast receiving device can be adjusted more accurately to Coordinated Universal Time. For example, the information of the program whose decoding timing and presentation timing are specified by Coordinated Universal Time can be adjusted at an appropriate timing. It can be decoded and presented. Further, for example, since the transmission frequency of the transmission time information is often higher than the transmission frequency of the time adjustment information, the broadcast receiving device uses the transmission time information that is frequently received even if its own time shifts. , You can correct your time early.

(10) The broadcast retransmission program according to the embodiment of the present invention is a broadcast retransmission program used in a broadcast retransmission device, and is a transmission generated by demodulating a broadcast wave according to the MMT method by a computer. An acquisition unit that acquires a stream containing a null packet for adjusting the rate, a deletion unit that deletes the null packet from the stream acquired by the acquisition unit, and a deletion unit that deletes the null packet by the deletion unit. It is a program for functioning as a transmitter that transmits a stream to another device via a communication line.

In the broadcast wave, for example, a null packet for bit rate adjustment may be inserted in order to fix the transmission rate according to the transmission device of the broadcast wave. As described above, by deleting null packets from the stream, the amount of transmitted data can be reduced as compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet, so that the communication line can be used. Communication traffic can be reduced. As a result, it is possible to suppress transmission delays in program information and fluctuations in transmission time. Therefore, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.

(11) The broadcast retransmission program according to the embodiment of the present invention is a broadcast retransmission program used in the broadcast retransmission device, and is a program generated by demodulating a broadcast wave according to the MMT method by a computer. An acquisition unit that acquires a stream including a variable packet having a variable size containing the information of the above, a divided storage unit that creates a plurality of fixed packets having a predetermined size including data obtained by dividing the variable packet, and the divided storage unit. It is a program for functioning as a transmission unit which transmits the stream including each fixed packet created by the unit in place of the variable packet to another device via a communication line.

For example, when a variable packet is converted into an IP packet as it is, a jumbo packet having a size larger than that of the MTU may be generated. With the above configuration, for example, by adjusting the number of fixed packets stored in the payload of the IP packet, it is possible to generate an IP packet having an appropriate size smaller than the MTU. As a result, the IP packet can be transmitted without being fragmented on a communication line such as the Internet. Therefore, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.

(12) The broadcast reception program according to the embodiment of the present invention is a broadcast reception program used in a broadcast reception device including a clock generation unit that generates a reference clock and a counter that updates a count value based on the reference clock. In order to make the computer function as a receiver for receiving a stream from another device from which null packets for adjusting the transmission rate have been deleted from the stream generated by demodulating the broadcast wave according to the MMT method. The stream is a plurality of fixed packets having a predetermined size, each of which includes divided data in a variable size packet containing program information, and is a time for adjusting the time between devices. The clock generation includes a fixed packet to which transmission time information is added, which indicates a count value calibrated using the combined information as a transmission timing, and further, the computer uses the transmission time information added to the fixed packet. This is a program for functioning as a synchronization processing unit that controls at least one of a unit and the counter.

In the broadcast wave, for example, a null packet for bit rate adjustment may be inserted in order to fix the transmission rate according to the transmission device of the broadcast wave. As described above, by deleting null packets from the stream, the amount of transmitted data can be reduced as compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet, so that the communication line can be used. Communication traffic can be reduced. As a result, it is possible to suppress transmission delays in program information and fluctuations in transmission time. Therefore, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.
Further, at least one of the clock generator and the counter is used by using the transmission time information indicating the count value calibrated using the time adjustment information included in the broadcast wave in which the transmission time does not fluctuate as the transmission timing. By controlling one of them, the time of the broadcast receiving device can be adjusted more accurately to Coordinated Universal Time. For example, the information of the program whose decoding timing and presentation timing are specified by Coordinated Universal Time can be adjusted at an appropriate timing. It can be decoded and presented. Further, for example, since the transmission frequency of the transmission time information is often higher than the transmission frequency of the time adjustment information, the broadcast receiving device uses the transmission time information that is frequently received even if its own time shifts. , You can correct your time early.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated. In addition, at least a part of the embodiments described below may be arbitrarily combined.

FIG. 1 is a diagram showing a configuration of a broadcast retransmission system according to an embodiment of the present invention.

With reference to FIG. 1, the broadcast retransmission system 301 includes a broadcast retransmission device 101 and a plurality of IP broadcast receiving devices 102.

The broadcast retransmission system 301 is not limited to the configuration including a plurality of IP broadcast receiving devices 102, and may be configured to include one IP broadcast receiving device 102.

The broadcast retransmission device 101 and the router 121 are provided in, for example, the IPTV center 151.

The ONU (Optical Network Unit) 122, STB131, TV receiver 132, and TV monitor 133 are provided in the subscriber's home 152. The STB 131 and the TV receiver 132 include an IP broadcast receiving device 102.

For example, an external antenna 11 is connected to the broadcast retransmission device 101. The broadcast retransmission device 101 receives, for example, a broadcast wave including a stream.

The stream contains program information and the like. The program information includes, for example, audio information, video information, EPG (Electronic Program Guide) information, SI information (Service Information), subtitle information, and the like.

The audio information and the video information are compressed and encrypted according to a predetermined method, for example.

The broadcast retransmission device 101 receives, for example, a broadcast wave transmitted from a broadcast satellite for advanced broadband satellite digital broadcasting (not shown) for relaying a stream from a broadcast station via an external antenna 11.

The broadcast retransmission device 101 may, for example, receive the broadcast wave transmitted from the radio tower via the external antenna 11.

FIG. 2 is a diagram showing an example of a protocol stack of data transmitted by broadcast waves in the broadcast retransmission system according to the embodiment of the present invention. FIG. 2 shows a protocol stack using TLV packets.

With reference to FIG. 2, TLV packets are often used for transmission such as 4K UHDTV (Ultra High Definition Television) or 8K UHDTV according to standards such as 2160p or 4320p.

Here, the broadcast wave includes, for example, TMCC information, AC information and TLV packets.

FIG. 3 is a diagram showing an example of a TLV packet transmitted by a broadcast wave in the broadcast retransmission system according to the embodiment of the present invention. FIG. 3 shows an example of a packet having a header in which information indicating a data type is stored, Non-Patent Document 2 (International Telecommunication Union Radiocommunication Sector, “Recommunication ITU-R BT.1869”, March 2010, [ online], [Search on August 29, 2017], Internet <URL: http: //www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.1869-0-201003- The format of the TLV packet according to the standard of I !! PDF-E. Pdf>) is shown.

The TLV packet includes a TLV header and a TLV payload. The TLV header includes a "start code" field containing a value of "01", a "future reservation" field, a "packet type" field, and a "length" field, and the lengths of these fields. Are 2 bits, 6 bits, 8 bits and 16 bits, respectively.

Values such as "0x01", "0x02", "0x03", and "0xFF" are stored in the "packet type" field. Here, the numbers starting with "0x" mean that the numbers after "0x" are represented by hexadecimal numbers.

When "0x01" is stored in the "packet type" field, the TLV packet 61 includes an IPv4 packet that is the total data length of the values stored in the "length" field in the TLV payload.

Further, when "0x02" is stored in the "packet type" field, the TLV packet 62 includes an IPv6 packet which is the total data length of the value stored in the "length" field in the TLV payload.

Further, when "0x03" is stored in the "packet type" field, the TLV packet 63 includes an IP packet which is the total data length of the value stored in the "length" field in the TLV payload. A compressed IP packet is, for example, an IP packet in which an IP header is compressed.

Further, when "0xFF" is stored in the "packet type" field, the TLV packet 64 includes null data which is the total data length of the values stored in the "length" field in the TLV payload. Hereinafter, a TLV packet containing null data in the TLV payload is also referred to as a TLV null packet.

With reference to FIG. 2 again, for example, NTP (Network Time Protocol) data for time synchronization, IP-SI data, time information, MMT packet, or data transmission method is stored in UDP (User Datagram Protocol) / IP packet. Will be done. Video information, audio information, MMT-SI data, and other information are stored in the MMT packet.

The TLV packets 61 to 63 store such UDP / IP packets.

FIG. 4 is a diagram showing another example of a protocol stack of data transmitted by a broadcast wave. FIG. 4 shows a protocol stack using TS (Transport Stream) packets.

With reference to FIG. 4, TS packets are often used for transmission such as HDTV or SDTV (Standard Definition Television) according to standards such as 1080i, 720p or 480p. The TS packet may be used for transmission of 4K UHDTV, 8K UHDTV, or the like.

Here, the broadcast wave includes, for example, TMCC information, AC information and TS packets.

FIG. 5 is a diagram showing an example of a TS packet transmitted by a broadcast wave. FIG. 5 shows the format of the TS packet.

The TS packet 71 includes a TS header and a TS payload. The TS header includes a "synchronous byte" field in which the value of "0x47" is stored and a field for storing "PID (Packet ID), etc.", and the lengths of these fields are, for example, 1 octet and 1 octet, respectively. It is 3 octets. The TS payload includes, for example, a "payload" field for storing all or part of the PES (Packetized Elementary Stream) or all or part of the section. The length of this field is, for example, 184 octets.

With reference to FIG. 4 again, the PCR (Program Lock Reference) data is stored in, for example, TS packet 71. Further, for example, video information, audio information, subtitle information, and timeline are stored in the PES packet.

In addition, for example, PSI-SI data and a part of AIT (Application Information Table) are included in the section. Also included in the section are the rest of AIT, the app HTML and content downloads, which are transmitted in a data carousel fashion.

With reference to FIG. 1 again, the broadcast retransmission device 101 acquires program information from the broadcast wave and stores the acquired program information in an IP packet. Then, the broadcast retransmission device 101 transmits an IP packet containing program information (hereinafter, also referred to as a distribution IP packet) to each subscriber's home 152.

Here, the broadcast retransmission device 101 sets, for example, the destination of the distribution IP packet to an IP multicast address that reaches a plurality of subscribers' homes 152, and transmits the IP packet to the router 121.

The router 121 is, for example, an IP multicast router, and when a distribution IP packet is received from the broadcast retransmission device 101, the received distribution IP packet is transmitted to an IPTV transmission network (CDN: Content Delivery Network) which is an example of a communication line. Send to 10. In the IPTV transmission network 10, for example, distribution IP packets are transmitted according to the IP protocol. The communication line may be another communication line such as the Internet.

Further, the IPTV center 151 may be provided with an OLT (Optical Line Thermal) instead of the router 121.

The ONU 122 receives, for example, a distribution IP packet transmitted from the broadcast retransmission device 101 by a communication service of FTTH (Fiber To The Home).

More specifically, the ONU 122 is a home-side device in, for example, GPON (Gigabit Passive Optical Network) and GE-PON (Gigabit Ethernet®-PON).

When the ONU 122 receives a distribution IP packet from the IPTV transmission network 10 via an optical communication line, the ONU 122 transmits the received distribution IP packet to the STB 131 and the TV receiver 132.

When the IP broadcast receiving device 102 in the STB 131 receives the distribution IP packet from the ONU 122, it acquires program information from the received distribution IP packet, decodes audio information and video information based on the acquired program information, and then decodes the audio information and video information. The decoded audio information and video information are transmitted to the TV monitor 133.

The TV monitor 133 reproduces the program based on the audio information and the video information received from the STB 131.

Further, the IP broadcast receiving device 102 of the TV receiver 132 reproduces a program in the speaker module and the display module of its own TV receiver 132 by using the similarly decoded audio information and video information.

Here, in the transmission of 4K UHDTV and 8K UHDTV, as shown in FIG. 2, the MMT packet stored in the IP multicast packet is transmitted by the broadcast wave.

When performing an IP retransmission service for retransmitting such an MMT packet according to the IP protocol (see FIG. 1), for example, an IP header including an appropriately set IP address and port number is added to the TLV packet to provide the IP packet. A method of generating and transmitting the generated IP packet to the IPTV transmission network 10 can be considered.

However, when a TLV packet is converted into an IP packet, a jumbo packet having a size slightly larger than the MTU is often generated.

In many networks and transmission devices constituting the IPTV transmission network 10, such jumbo packets cannot be transmitted as they are, so the jumbo packets are fragmented into a plurality of packets and transmitted.

At this time, a large number of small-sized IP packets are generated as fragments of the fragmented jumbo packets. When such small-sized IP packets are continuously generated, the processing of the multicast signal in the transmission device overflows, and packet loss may occur.

Further, in the broadcast wave, a TLV null packet (see FIG. 3) for adjusting the bit rate is inserted in order to make the bit rate fixed according to the transmission device of the broadcast wave. Therefore, the amount of data transmitted by the TLV packet in the broadcast wave is larger than the amount of data of the program information.

Unlike broadcast waves, the IP retransmission service cannot occupy a band, so it is required that the amount of data to be transmitted is small.

Further, when the TLV packet is converted into an IP packet and transmitted, the conventional MPEG2-TS technical system related to transmission, simultaneous recording, measurement, etc. cannot be utilized.

Therefore, in the broadcast retransmission system according to the embodiment of the present invention, the above problem is solved by the following configuration and operation.

FIG. 6 is a diagram showing a configuration of a broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention.

With reference to FIG. 6, the broadcast retransmission device 101 includes a high-accuracy oscillator (transmission side clock generation unit) 21, a counter (transmission side counter) 22, a demodulation unit (acquisition unit) 23, and an NTP packet acquisition unit 24. A conversion unit (time synchronization unit) 25, a deletion unit 26, a TS conversion unit (divided storage unit) 27, a TTS conversion unit (additional unit) 28, a blocking unit 29, and an IP packetization unit 30. To be equipped.

The high-accuracy oscillator 21 generates, for example, a transmitting side reference clock. More specifically, the high-accuracy oscillator 21 is, for example, an oscillator that generates a high-precision clock pulse of 27 MHz synchronized with time information included in radio waves transmitted from a GPS (Global Positioning System) satellite. The high-accuracy oscillator 21 outputs the generated clock pulse to the counter 22.

The high-accuracy oscillator 21 may be configured to generate a high-precision clock pulse by using an OCXO (Oven Control Oscillator), a rubidium oscillator, or the like.

The counter 22 updates the transmitter count value according to, for example, the timing of the transmitter reference clock generated by the high-accuracy oscillator 21.

More specifically, the counter 22 counts the clock pulse from the high-accuracy oscillator 21 and holds the transmitted side count value which is the counted value.

The sender count can represent, for example, Coordinated Universal Time with an accuracy of 27 MHz.

The broadcast wave in the broadcast retransmission system 301 is for adjusting the time between devices using the above-mentioned TLV null packet, a variable packet having a variable size, that is, a variable data size including program information, and Coordinated Universal Time. It includes time adjustment information and follows the MMT method.

Here, the TLV packet is an example of a variable packet. The NTP data is an example of time adjustment information.

The demodulation unit 23 receives the broadcast wave and demodulates the received broadcast wave to generate a stream including the TLV null packet, the variable packet, and the time adjustment information.

More specifically, the demodulation unit 23 receives the broadcast wave via the external antenna 11 and demodulates the received broadcast wave to generate a stream composed of a plurality of TLV packets (see FIG. 2). In the stream, for example, NTP data is transmitted every 33 milliseconds.

The demodulation unit 23 outputs the generated stream to the NTP packet acquisition unit 24 and the deletion unit 26.

The NTP packet acquisition unit 24 receives a stream from the demodulation unit 23, acquires an IP packet containing NTP data (hereinafter, also referred to as an NTP packet) from the received stream, and outputs the acquired NTP packet to the conversion unit 25. ..

The conversion unit 25 adjusts the time to the counter 22 by using, for example, the NTP data included in the broadcast wave.

More specifically, the conversion unit 25 receives the NTP packet from the NTP packet acquisition unit 24, and acquires the Coordinated Universal Time (UTC) in the NTP length format from the NTP data included in the received NTP packet.

The NTP length format has a 32-bit field indicating seconds and a 32-bit field indicating 1 second or less.

The conversion unit 25 holds a formula for converting Coordinated Universal Time in NTP length format into a transmission side count value (hereinafter, also referred to as a transmission side conversion formula).

The difference between the time based on the transmission side count value and Coordinated Universal Time is acceptable up to, for example, about 500 nanoseconds. Since one count of the transmission side count value corresponds to about 37 nanoseconds, even if the transmission side count value fluctuates by about 10 counts, it falls within the permissible range.

For example, when the frequency accuracy of the high-accuracy oscillator 21 is 1 ppm, it is considered that the transmitting side count value deviates by 1 count about every 37 milliseconds, so that the transmitting side count value is deviated by 1 count every 10 NTP data, that is, every 330 milliseconds. By calibrating, the time based on the sender count value can be synchronized with Coordinated Universal Time with sufficient accuracy.

In this example, the conversion unit 25 converts Coordinated Universal Time into a transmission side count value using the transmission side conversion formula every time an NTP packet is received from the NTP packet acquisition unit 24, that is, every 33 milliseconds, and after conversion. The transmitter count value of is set in the counter 22.

The deletion unit 26 deletes the TLV null packet from the stream generated by the demodulation unit 23.

More specifically, the deletion unit 26 monitors the stream received from the demodulation unit 23 and attempts to detect the start code in the TLV header (see FIG. 3).

When the deletion unit 26 detects the start code, the deletion unit 26 confirms the value stored in the packet type field after the start code.

When the value stored in the above field is 0xFF, the deletion unit 26 determines that the TLV packet including the start code is a TLV null packet, and deletes the TLV packet from the stream.

On the other hand, when the value stored in the above field is a value other than 0xFF, the deletion unit 26 determines that the TLV packet including the start code is not a TLV null packet, and outputs the TLV packet to the TS conversion unit 27. ..

FIG. 7 is a diagram showing an example of a TLV packet division method performed in the broadcast retransmission device according to the embodiment of the present invention.

In FIG. 7, a TLV packet described in Non-Patent Document 3 (“JCTEA STD-002-6.0 Digital Cable Television Broadcast Multiplexing Device”, Japan CATV Technology Association) is converted into a plurality of TS packets. Shows how to store.

FIG. 8 is a diagram showing an example of the TS packet format shown in FIG. 7.

With reference to FIGS. 7 and 8, the TS conversion unit 27 creates a plurality of fixed packets having a predetermined size, each including divided data of the TLV packets included in the stream. Here, the TS packet has a size of 188 bytes and is an example of a fixed packet.

More specifically, the TS conversion unit 27 has, for example, a buffer for holding unstored data.

When the TS conversion unit 27 receives the TLV packet 1 (see FIG. 7) from the deletion unit 26, for example, when the unstored data is not stored in the buffer, the TS conversion unit 27 receives, for example, from the beginning of the received TLV packet 1 to 184 bytes. Data is acquired as a split TLV packet.

The TS conversion unit 27 added a 3-byte TS header and, if a TLV header, a 1-byte head TLV instruction, to the acquired divided TLV packet, so that the divided TLV packet was stored in the payload. A TS packet (hereinafter referred to as a TLV-stored TS packet) is created, and the created TLV-stored TS packet is output to the TTS conversion unit 28.

Similarly, each time the TS conversion unit 27 acquires 185 bytes of data from the beginning of the remaining data of the TLV packet 1 as a divided TLV packet, the TS conversion unit 27 creates a TLV storage TS packet and outputs the data to the TTS conversion unit 28.

Further, when the size of the acquired data is less than 185 bytes, the TS conversion unit 27 saves the acquired data as unstored data in the buffer.

Then, when the TS conversion unit 27 receives the subsequent TLV packet 2 (see FIG. 7) from the deletion unit 26, the unstored data is stored in the buffer, so the size obtained by subtracting the size of the unstored data from 184 bytes. Data is acquired from the beginning of the TLV packet 2.

The TS conversion unit 27 adds unstored data to the beginning of the acquired data, arranges the head TLV instruction and the data of the TLV packet 2 to create a divided TLV packet, and then discards the unstored data in the buffer.

The TS conversion unit 27 adds a TS header to the created divided TLV packet to create a TLV storage TS packet, and outputs the created TLV storage TS packet to the TTS conversion unit 28.

The TS conversion unit 27 is configured to create the TLV-stored TS packet shown in FIGS. 7 and 8, but is not limited to this. The TS conversion unit 27 has a TS header including a synchronization byte at the beginning, and if the TS packet has a size of 188 bytes, for example, the TS packet having the format shown in FIG. 5 stores the divided TLV packet. It may be.

In this way, with the configuration using TS packets, the TSoverIP recording device, measuring device, monitoring device, and the like utilized in the MPEG2-TS technical system can be used.

With reference to FIG. 6 again, the TTS conversion unit 28 adds, for example, transmission time information indicating the transmission timing of the TLV-stored TS packet to the TLV-stored TS packet.

Specifically, the TTS conversion unit 28 adds transmission time information indicating the transmission timing of the TLV-stored TS packet by the transmission side count value to the TLV-stored TS packet.

More specifically, when the TTS conversion unit 28 receives the TLV storage TS packet from the TS conversion unit 27, it acquires the transmission side count value from the counter 22, and uses the acquired transmission side count value as the TS of the TLV storage TS packet. Prepend it as a time stamp before the header.

Hereinafter, the TLV-stored TS packet to which the time stamp is added is also referred to as a TLV-stored TTS (Time-stopped TS) packet.

The size of the time stamp is a predetermined size, for example, 4 bytes. Therefore, the size of the TLV-stored TTS packet is a fixed length of 192 bytes.

The TTS conversion unit 28 outputs the created TLV storage TTS packet to the blocking unit 29.

The blocking unit 29 accumulates a predetermined number of TLV-stored TTS packets received from the TTS-forming unit 28.

More specifically, for example, 1500 bytes is often used as the MTU size. In this case, if seven TLV-stored TTS packets are collectively transmitted as one IP packet, the transmission efficiency in the IPTV transmission network 10 can be improved. ..

In this example, the blocking unit 29 accumulates seven TLV-stored TTS packets and then outputs these seven TLV-stored TTS packets as one block data to the IP packetizing unit 30.

Based on the block data, the blocking unit 29 performs FEC processing for adding an FEC (Forward Error Correction) packet for forward error correction as additional block data, for example, in accordance with the SMPTE 2022 standard (pro MPEG COP3). You may.

Upon receiving the block data from the blocking unit 29, the IP packetizing unit 30 adds, for example, an RTP (Real-time Transport Protocol) header, a UDP (User Datagram Protocol) header, and an IP header to the received block data. Creates an IP packet, that is, an IP packet for distribution.

The IP multicast address of the destination in the IP header and the destination port number in the UDP header can be set to arbitrary values by the operator. The IP packetization unit 30 outputs the created distribution IP packet to the IP transmission unit 31.

The IP transmission unit 31 transmits a stream from which the TLV null packet has been deleted by the deletion unit 26 to the IP broadcast receiving device 102 via the IPTV transmission network 10.

More specifically, the IP transmission unit 31 transmits the distribution IP packet received from the IP packetization unit 30 to the router 121.

[Configuration and operation of IP broadcast receiving device 102]
FIG. 9 is a diagram showing a configuration of an IP broadcast receiving device in the broadcast retransmission system according to the embodiment of the present invention.

With reference to FIG. 9, the IP broadcast receiving device 102 includes an IP receiving unit 41, a time stamp separating unit 42, a clock adjusting unit (synchronous processing unit) 43, and a VCO (Voltage-Control Oscillator) (reception side clock generation). A unit) 44, a PCR (Program Clock Reference) counter (reception side counter) 45, a calibration unit (synchronization processing unit) 46, a conversion unit 47, a TLV resynthesis unit 48, and a decoding unit 49.

The VCO 44 generates a receiving side reference clock. More specifically, the VCO 44 is capable of generating a clock pulse having a frequency corresponding to the magnitude of the voltage received from the clock regulator 43 in a predetermined frequency range including 27 MHz. The VCO 44 outputs the generated clock pulse to the PCR counter 45.

The PCR counter 45 updates the receiving side count value according to the timing of the receiving side reference clock. More specifically, the PCR counter 45 counts the clock pulses from the VCO 44 and holds the received side count value which is the counted value.

The IP receiving unit 41 receives the TLV-stored TTS packet from the broadcast retransmission device 101.

More specifically, when the IP receiving unit 41 receives the distribution IP packet from the broadcast retransmission device 101 via the IPTV transmission network 10, the IP receiving unit 41 outputs the received distribution IP packet to the time stamp separation unit 42.

When the time stamp separation unit 42 receives the distribution IP packet from the IP reception unit 41, for example, the time stamp separation unit 42 acquires block data, that is, seven TLV-stored TTS packets from the payload of the RTP packet in the received distribution IP packet.

The time stamp separation unit 42 removes the time stamp from the acquired TLV-stored TTS packet to create a TLV-stored TS packet.

The time stamp separation unit 42 outputs the removed time stamp to the clock adjustment unit 43 and the calibration unit 46, and outputs the created TLV storage TS packet to the TLV resynthesis unit 48.

The clock adjusting unit 43 and the calibration unit 46 control the PCR counter 45 by using the transmission time information or time stamp added to the TLV-stored TTS packet. More specifically, the transmitting side sets a time based on the receiving side count value. Synchronize with the time based on the count value.

The calibration unit 46 performs a calibration process for calibrating the receiving side count value in the PCR counter 45 using the time stamp. More specifically, when the calibration unit 46 receives a time stamp from the time stamp separation unit 42, the calibration unit 46 adjusts the time based on the receiving side count value to the time based on the transmitting side count value by using the received time stamp.

Specifically, the calibration unit 46 sets, for example, the reception side count value in the PCR counter 45 to the value of the time stamp received from the time stamp separation unit 42.

By using a 27 MHz oscillator in both the broadcast retransmission device 101 and the IP broadcast receiving device 102, it is possible to easily calibrate the receiving side count value in the IP broadcasting receiving device 102.

The calibration unit 46 is not limited to a configuration in which the reception side count value is calibrated each time a time stamp is received from the time stamp separation unit 42. For example, the calibration unit 46 calibrates the reception side count value using the latest time stamp every predetermined cycle. It may be configured to be.

The clock adjustment unit 43 uses the time stamp to perform an adjustment process for synchronizing the reception-side reference clock with the transmission-side clock. Specifically, the clock adjusting unit 43 uses the time stamp to match the speed of time advance based on the receiving side count value with the speed of time advancing based on the transmitting side count value.

More specifically, the clock adjusting unit 43 adjusts the output voltage to the VCO 44 to match the oscillation frequency of the VCO 44 with the oscillation frequency of the high-accuracy oscillator 21 in the broadcast retransmission device 101.

When the clock adjusting unit 43 receives the time stamp from the time stamp separating unit 42, the clock adjusting unit 43 acquires the receiving side count value from the PCR counter 45 and compares the time stamp value with the receiving side count value.

The clock adjusting unit 43 determines the output voltage to the VCO 44 based on the comparison result, and outputs the determined voltage to the VCO 44.

Specifically, for example, when the value of the time stamp is larger than the reception side count value, the clock adjusting unit 43 determines the output voltage to the VCO 44 so that the oscillation frequency in the VCO 44 becomes large.

Further, for example, when the value of the time stamp is smaller than the reception side count value, the clock adjustment unit 43 determines the output voltage to the VCO 44 so that the oscillation frequency in the VCO 44 becomes smaller.

Each time the TLV resynthesis unit 48 receives a TLV storage TS packet from the time stamp separation unit 42, the TLV resynthesis unit 48 acquires data from the payload in the received TLV storage TS packet.

The TLV resynthesis unit 48 reproduces the TLV packet by combining the acquired data in the order of arrival from the time stamp separation unit 42 (see FIG. 7). The TLV resynthesis unit 48 outputs the reproduced TLV packet to the decoding unit 49.

The conversion unit 47 holds a formula for converting the receiving side count value at the time of the agreement world (hereinafter, also referred to as a receiving side conversion formula).

For example, the conversion unit 47 acquires the receiving side count value from the PCR counter 45 every time the receiving side count value in the PCR counter 45 increases by a predetermined amount, and uses the receiving side conversion formula to obtain the acquired receiving side count value. Convert to Agreement World Time. The conversion unit 47 outputs the converted Coordinated Universal Time to the decoding unit 49.

When the decoding unit 49 receives the TLV packet from the TLV resynthesis unit 48, the decoding unit 49 acquires the MMT packet from the received TLV packet and decodes the video information and the audio information included in the acquired MMT packet (see FIG. 2).

More specifically, the decoding unit 49 describes the following based on the MPU (Media Processing Unit) time stamp descriptor and the MPU extended time stamp descriptor included in the MMT packet, for example, according to the method described in Non-Patent Document 1. Perform processing.

That is, the decoding unit 49 calculates the decoding timing of the video information and the audio information, and the presentation timing of the audio information and the video information. The decoding timing and the presentation timing are represented by the 64-bit NTP length format described above.

The decoding unit 49 periodically monitors the Coordinated Universal Time received from the conversion unit 47, and when the decoding timing of the video information coincides with the Coordinated Universal Time, the decoding unit 49 decodes the video information.

Similarly, the decoding unit 49 decodes the audio information when the decoding timing of the audio information coincides with Coordinated Universal Time.

Further, when the presentation timing of the video information coincides with the time of the world agreement, the decoding unit 49 transmits the decoded video information as playback information to the TV monitor 133 or the display module in the TV receiver 132.

Similarly, when the presentation timing of the audio information coincides with the time of the world agreement, the decoding unit 49 transmits the decoded audio information as reproduction information to the TV monitor 133 or the speaker module in the TV receiver 132.

In the MPEG2-TS system, the time stamp in the TTS packet was not used for the purpose of decoding and presenting video information and audio information.

As described above, by including the time stamp consistent with the NTP data in the TTS packet, the time stamp can be used for the adjustment process, the calibration process, and the decoding timing and the presentation timing.

[Operation flow]
Each device in the broadcast retransmission system 301 includes a computer, and an arithmetic processing unit such as a CPU in the computer reads a program including a part or all of each step of the following sequence diagram or flowchart from a memory (not shown). Run. The programs of these plurality of devices can be installed from the outside. The programs of these plurality of devices are distributed in a state of being stored in a recording medium.

FIG. 10 is a flowchart defining an operation procedure when the broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention calibrates the transmission side count value.

With reference to FIG. 10, the broadcast retransmission device 101 receives the broadcast wave transmitted from the broadcast satellite via the external antenna 11, and demodulates the received broadcast wave to form a stream composed of a plurality of TLV packets. Is generated.

First, the broadcast retransmission device 101 waits for the calibration process of the transmission side count value in the counter 22 until the NTP packet is acquired from the generated stream (NO in step S101).

Then, when the broadcast retransmission device 101 acquires an NTP packet from the generated stream (YES in step S101), it acquires Coordinated Universal Time from the acquired NTP packet (step S102).

Next, the broadcast retransmission device 101 converts the acquired Coordinated Universal Time into a transmitting side count value using the transmitting side conversion formula (step S103).

Next, the broadcast retransmission device 101 sets the converted transmission side count value in the counter 22 (step S104).

Next, the broadcast retransmission device 101 waits for the calibration process of the transmission side count value in the counter 22 until a new NTP packet is acquired from the generated stream (NO in step S101).

FIG. 11 is a flowchart defining an operation procedure when the broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention processes a TLV packet.

With reference to FIG. 11, first, the broadcast retransmission device 101 monitors the generated stream and waits for the processing of the TLV packet until the start code in the TLV packet is detected (NO in step S201).

Then, when the broadcast retransmission device 101 detects the start code in the TLV packet (YES in step S201), the broadcast retransmission device 101 acquires the value stored in the packet type field after the detected start code (step S202).

Next, when the acquired value is not a transmission target such as 0xFF (YES in step S203), the broadcast retransmission device 101 waits for the processing of the TLV packet until it detects a new start code (NO in step S201). ).

On the other hand, when the acquired value is the transmission target (NO in step S203), the broadcast retransmission device 101 determines that the TLV packet including the start code is not a TLV null packet, and holds the unstored data in the buffer. It is confirmed whether or not it is present (step S204).

When the broadcast retransmission device 101 does not hold the unstored data in the buffer (NO in step S204), the broadcast retransmission device 101 sets the amount of data to be acquired to 184 bytes (step S209).

Next, the broadcast retransmission device 101 attempts to acquire 184 bytes of data from the TLV packet including the start code (step S210).

On the other hand, when the broadcast retransmission device 101 holds the unstored data in the buffer and the unstored data is less than 185 bytes (YES in step S204 and NO in step S215), the unstored data starts from 184 bytes. A value obtained by subtracting the size is calculated, and the calculated value is set as the amount of data to be acquired (step S205).

Next, the broadcast retransmission device 101 attempts to acquire data for a set amount of data from the TLV packet including the start code (step S206).

Next, the broadcast retransmission device 101 adds unstored data to the beginning of the acquired data (step S207).

Next, the broadcast retransmission device 101 discards the unstored data from the buffer (step S208).

Next, the broadcast retransmission device 101 attempts to acquire 184 bytes of data (step S210), or discards the unstored data from the buffer (step S208) to determine whether 185 bytes of data can be secured. Confirm (step S211).

When the broadcast retransmission device 101 cannot secure 185 bytes of data (NO in step S211), the broadcast retransmission device 101 saves the secured data in the buffer as unstored data (step S214).

Next, the broadcast retransmission device 101 waits for the processing of the TLV packet until it detects a new start code (NO in step S201).

On the other hand, when the broadcast retransmission device 101 can secure 185 bytes of data (YES in step S211), the broadcast retransmission device 101 creates a TLV-stored TS packet by adding a TS header to the secured 185 bytes of data (step). S212).

Next, the broadcast retransmission device 101 creates a TLV-stored TTS packet by acquiring a transmitting-side count value from the counter 22 and adding the acquired transmitting-side count value as a time stamp to the beginning of the TLV-stored TS packet (). Step S213).

Next, the broadcast retransmission device 101 confirms whether or not the unstored data is held in the buffer (step S204).
On the other hand, when the broadcast retransmission device 101 holds the unstored data in the buffer and the unstored data is 185 bytes or more (YES in step S204 and YES in step S215), the broadcast retransmission device 101 starts from the beginning of the unstored data 185. The data for bytes is acquired to create a TLV-stored TS packet (step S212), a TLV-stored TTS packet is created (step S213), and it is checked again whether or not the unstored data is held in the buffer (step). S204).

FIG. 12 is a flowchart defining an operation procedure when the broadcast retransmission device in the broadcast retransmission system according to the embodiment of the present invention creates an IP packet for distribution.

With reference to FIG. 12, first, the broadcast retransmission device 101 waits for the distribution IP packet creation process until, for example, seven TLV-stored TTS packets are secured (NO in step S301).

Then, when the broadcast retransmission device 101 secures the seven TLV-stored TTS packets (YES in step S301), the broadcast retransmission device 101 creates one block data by combining the seven TLV-stored TTS packets (step S302).

Next, the broadcast retransmission device 101 creates an IP packet, that is, a distribution IP packet by adding an RTP header, a UDP header, and an IP header to the created block data (step S303).

Next, the broadcast retransmission device 101 transmits the created distribution IP packet to the router 121 (step S304).

Next, the broadcast retransmission device 101 waits for the process of creating the distribution IP packet until it secures seven new TLV-stored TTS packets (NO in step S301).

FIG. 13 is a flowchart defining an operation procedure when the IP broadcast receiving device in the broadcast retransmission system according to the embodiment of the present invention calibrates the receiving side count value.

With reference to FIG. 13, first, the IP broadcast receiving device 102 waits for the calibration process of the receiving side count value until it receives the distribution IP packet from the broadcast retransmission device 101 (NO in step S401).

Then, when the IP broadcast receiving device 102 receives the distribution IP packet from the broadcast retransmission device 101 (YES in step S401), the IP broadcast receiving device 102 acquires a time stamp from the TLV-stored TTS packet in the received distribution IP packet (step S402). ..

Next, the IP broadcast receiving device 102 sets the receiving side count value in the PCR counter 45 to the value of the acquired time stamp (step S403).

Next, the IP broadcast receiving device 102 waits for the calibration process of the receiving side count value until a new distribution IP packet is received from the broadcast retransmission device 101 (NO in step S401).

FIG. 14 is a flowchart defining an operation procedure when the IP broadcast receiving device in the broadcast retransmission system according to the embodiment of the present invention adjusts the oscillation frequency in the VCO.

With reference to FIG. 14, first, the IP broadcast receiving device 102 waits for the oscillation frequency adjustment process until it receives the distribution IP packet from the broadcast retransmission device 101 (NO in step S501).

Then, when the IP broadcast receiving device 102 receives the distribution IP packet from the broadcast retransmission device 101 (YES in step S501), the IP broadcast receiving device 102 acquires a time stamp from the TLV stored TTS packet in the received distribution IP packet (step S502). ..

Next, the IP broadcast receiving device 102 acquires the receiving side count value in the PCR counter 45 (step S503).

Next, the IP broadcast receiving device 102 calculates the difference between the time stamp value and the receiving side count value by subtracting the receiving side count value from the time stamp value (step S504).

Next, the IP broadcast receiving device 102 adjusts the output voltage to the VCO 44 according to the calculated difference (step S505).

Next, the IP broadcast receiving device 102 waits for the oscillation frequency adjustment process until it receives a new distribution IP packet from the broadcast retransmission device 101 (NO in step S501).

The broadcast retransmission device according to the embodiment of the present invention is said to have a configuration including a demodulation unit 23, but the present invention is not limited to this. The demodulation unit 23 may be provided outside the broadcast retransmission device 101, and the broadcast retransmission device 101 may include an acquisition unit that acquires the stream from the external demodulation unit 23.

Further, in the broadcast retransmission system according to the embodiment of the present invention, the variable packet is a TLV packet, but the present invention is not limited to this. The variable packet may be another packet such as an MMT packet.

Further, the broadcast retransmission device according to the embodiment of the present invention has a configuration in which a TLV packet is divided into a plurality of TLV-stored TTS packets and stored, and a distribution IP packet including seven TLV-stored TTS packets is transmitted. However, it is not limited to this. The broadcast retransmission device 101 may be configured to create a distribution IP packet by adding an IP header to the TLV packet without dividing the TLV packet, and transmit the created distribution IP packet.

Further, the broadcast retransmission device according to the embodiment of the present invention is said to have a configuration in which a time stamp is added to the TLV stored TS packet, but the present invention is not limited to this. The broadcast retransmission device 101 may be configured not to add a time stamp to the TLV-stored TS packet.

Further, the broadcast retransmission device according to the embodiment of the present invention is configured to include a pair of a high-accuracy oscillator 21 of 27 MHz and a counter 22, but the present invention is not limited to this. The broadcast retransmission device 101 may be configured to include an oscillator that generates a clock pulse having a frequency other than 27 MHz, for example, a 2 ^ n Hertz VCO described in Non-Patent Document 1, and a counter. Here, "a ^ b" means y to the xth power. However, while broadcast retransmission devices equipped with a set of a 2 ^ n-hertz VCO and a corresponding counter are not widely distributed, a set of a 27-megahertz oscillator and a counter 22 is used for the MPEG2-TS system. It is modularized and widely distributed. Therefore, a configuration including a pair of a high-accuracy oscillator 21 of 27 MHz and a counter 22 is preferable.

Further, in the broadcast retransmission device according to the embodiment of the present invention, the high-accuracy oscillator 21 is configured to synchronize with the time information included in the radio waves transmitted from the GPS satellites, but the present invention is not limited to this. Absent. The high-accuracy oscillator 21 may be configured to synchronize the high-accuracy oscillator 21 to 27 MHz by feeding back the difference between Coordinated Universal Time and the transmission side count value to the high-accuracy oscillator 21 using an NTP packet. .. For this feedback, for example, control of an analog PLL (Phase Locked Loop) circuit and various digital clock synthesizers is used.

Further, the IP broadcast receiving device according to the embodiment of the present invention is configured to include a pair of a VCO 44 of 27 MHz and a PCR counter 45, but the present invention is not limited to this. The IP broadcast receiving device 102 may be configured to include a pair of an oscillator that generates a clock pulse having a frequency other than 27 MHz, for example, the above-mentioned 2 ^ n Hertz VCO, and a counter. However, while IP broadcast receivers equipped with a 2 ^ n Hertz VCO and a counter pair are not widely available, a 27 megahertz oscillator pair with a PCR counter 45 is a module for the MPEG2-TS system. It has been converted and widely distributed. Therefore, a configuration including a pair of a 27 MHz VCO44 and a PCR counter 45 is preferable.

Further, the IP broadcast receiving device according to the embodiment of the present invention is configured to perform both calibration processing and adjustment processing, but the present invention is not limited to this. The IP broadcast receiving device 102 may be configured to perform either a calibration process or an adjustment process.

By the way, for example, in the case of performing an IP retransmission service for transmitting an advanced broadband satellite digital broadcast to a subscriber's home via an IPTV transmission network, a broadcast wave including an MMT packet is received and the received MMT packet is sent to the subscriber's home. A configuration is conceivable for retransmitting to the home device. A technique for efficiently performing such retransmission is desired.

On the other hand, in the broadcast retransmission device according to the embodiment of the present invention, the demodulation unit 23 includes a TLV null packet for adjusting the transmission rate generated by demodulating the broadcast wave according to the MMT method. Get the stream. The deletion unit 26 deletes the TLV null packet from the stream acquired by the demodulation unit 23. Then, the IP transmission unit 31 transmits the stream from which the TLV null packet has been deleted by the deletion unit 26 to the IP broadcast receiving device via the communication line.

In the broadcast wave, for example, a TLV null packet for bit rate adjustment may be inserted in order to fix the transmission rate according to the transmission device of the broadcast wave. As described above, by deleting the TLV null packet from the stream, the amount of transmitted data can be reduced as compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet. Communication traffic on the line can be reduced. As a result, it is possible to suppress transmission delays in program information and fluctuations in transmission time. Therefore, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.

Further, in the broadcast retransmission device according to the embodiment of the present invention, the stream further includes a variable size packet including program information, for example, a TLV packet. The TS conversion unit 27 creates a plurality of fixed packets having a predetermined size, for example, a TS packet, each containing divided data of the TLV packet included in the stream. Then, the IP transmission unit 31 transmits a stream containing each TS packet created by the TS conversion unit 27 instead of the TLV packet.

For example, when a TLV packet is converted into an IP packet as it is, a jumbo packet having a size larger than that of the MTU may be generated. With the above configuration, for example, by adjusting the number of TS packets stored in the payload of the IP packet, it is possible to generate an IP packet having an appropriate size smaller than the MTU. As a result, the IP packet can be transmitted on the Internet without being fragmented, so that the information of the program can be transmitted more efficiently.

Further, in the broadcast retransmission device according to the embodiment of the present invention, the deletion unit 26 adds transmission time information indicating the transmission timing of the TS packet to the TS packet.

The transmission rate of the stream from which the TLV null packet is deleted fluctuates. Further, in the communication line, fluctuations in the transmission time of TS packets and loss, duplication and replacement of TS packets may occur. Therefore, in other devices, it becomes difficult to manage the buffer based on the amount of received data. With the above configuration, in other devices, it is possible to correctly determine the excess or deficiency of the received data amount based on the transmission time information, so that buffer management can be easily performed.

Further, Non-Patent Document 1 describes a method of synchronizing a reference clock using an NTP packet in a device on the receiving side. However, in the communication line, fluctuations in the transmission time of NTP packets and loss, duplication and replacement of NTP packets may occur. Therefore, it becomes difficult to synchronize the reference clock using the NTP packet. Further, even when the transmission conditions on the communication line are good, it is necessary to repeat the correction calculation when synchronizing the reference clock, so that the burden of software processing on the receiving device becomes excessive.

On the other hand, in the broadcast retransmission device according to the embodiment of the present invention, the stream includes time adjustment information for performing time adjustment between the devices. The high-accuracy oscillator 21 generates a transmission-side reference clock. The counter 22 updates the transmitting side count value based on the transmitting side reference clock. The conversion unit 25 calibrates the transmission side count value of the counter 22 by using the time adjustment information included in the stream. The TTS conversion unit 28 adds transmission time information indicating a transmission side count value to the TS packet as a transmission timing.

In this way, the time of the broadcast retransmission device 101 is set by the broadcast wave transmission device by the configuration in which the time is adjusted to the counter 22 by using the time adjustment information included in the broadcast wave in which the transmission time does not fluctuate. It can be adjusted accurately by the time, for example, Coordinated Universal Time. Then, due to the configuration in which the transmission time information indicating the transmission side count value is added to the TS packet as the transmission timing of the TS packet, the other device sets its own time based on the transmission time information of the broadcast retransmission device 101. The time can be set, for example, Coordinated Universal Time. Thereby, for example, another device can decode or present the information of the program whose decoding timing and presentation timing are specified by Coordinated Universal Time at an appropriate timing. Further, for example, since the transmission frequency of the transmission time information is often higher than the transmission frequency of the time adjustment information, other devices use the transmission time information that is frequently received even if their own time shifts. , You can correct your time early.

Further, in the broadcast retransmission device according to the embodiment of the present invention, the demodulation unit 23 includes a variable size packet including program information, for example, a TLV packet, which is generated by demodulating a broadcast wave according to the MMT method. Get the stream. The TS conversion unit 27 creates a plurality of fixed packets having a predetermined size, for example, a TS packet, each containing divided data of the TLV packet included in the stream. Then, the IP transmission unit 31 transmits a stream containing each TS packet created by the TS conversion unit 27 instead of the TLV packet to the IP broadcast receiving device via the communication line.

For example, when a TLV packet is converted into an IP packet as it is, a jumbo packet having a size larger than that of the MTU may be generated. With the above configuration, for example, by adjusting the number of TS packets stored in the payload of the IP packet, it is possible to generate an IP packet having an appropriate size smaller than the MTU. As a result, the IP packet can be transmitted without being fragmented on a communication line such as the Internet. Therefore, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.

Further, in the IP broadcast receiving device according to the embodiment of the present invention, the IP receiving unit 41 deletes the TLV null packet for adjusting the transmission rate, and the variable size packet including the program information, for example, the TLV packet is deleted. A plurality of fixed packets having a predetermined size, for example, a TS packet, each containing divided data, and a transmission side count value calibrated using time adjustment information for time adjustment between devices is shown as a transmission timing. A stream including a TS packet to which transmission time information is added is received from the broadcast retransmission device 101. The VCO 44 generates a receiving side reference clock. The PCR counter 45 updates the receiver count value based on the receiver reference clock. Then, the calibration unit 46 controls the PCR counter 45 by using the transmission time information added to the TS packet.

In the broadcast wave, for example, a TLV null packet for bit rate adjustment may be inserted in order to fix the transmission rate according to the transmission device of the broadcast wave. As described above, by deleting the TLV null packet from the stream, the amount of transmitted data can be reduced as compared with the case where the TLV packet in the broadcast wave is transmitted as it is via a communication line such as the Internet. Communication traffic on the line can be reduced. As a result, it is possible to suppress transmission delays in program information and fluctuations in transmission time. Therefore, in a configuration in which a broadcast wave including program information is received and retransmitted to another device, program information can be efficiently transmitted.
Further, at least of the VCO 44 and the PCR counter 45, using the transmission time information indicating the transmission side count value calibrated using the time adjustment information included in the broadcast wave in which the transmission time does not fluctuate as the transmission timing. By controlling either one, the time of the IP broadcast receiving device 102 can be adjusted more accurately to Coordinated Universal Time. Therefore, for example, the information of the program whose decoding timing and presentation timing are specified by Coordinated Universal Time can be obtained. It can be decoded and presented at the right time. Further, for example, since the transmission frequency of the transmission time information is often higher than the transmission frequency of the time adjustment information, the IP broadcast receiving device 102 frequently receives the transmission time information even if its own time shifts. It can be used to correct one's time early.

It should be considered that the above embodiments are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

The above description includes the features described below.
[Appendix 1]
An acquisition unit that acquires a stream containing null packets for adjusting the transmission rate, which is generated by demodulating a broadcast wave according to the MMT method.
A deletion unit that deletes the null packet from the stream acquired by the acquisition unit, and a deletion unit.
A transmission unit for transmitting the stream from which the null packet has been deleted by the deletion unit to another device via a communication line is provided.
The acquisition unit receives a broadcast wave containing a TLV null packet and conforms to the MMT method from a broadcast satellite for advanced broadband satellite digital broadcasting, and demodulates the received broadcast wave to generate a stream containing the TLV null packet. And
The communication line is a broadcast retransmission device which is an IPTV transmission network.

[Appendix 2]
An acquisition unit that acquires a stream containing variable size packets containing program information, which is generated by demodulating a broadcast wave according to the MMT method.
A divided storage unit that creates a plurality of fixed packets having a predetermined size, each of which contains divided data of the variable packet.
A transmission unit for transmitting the stream including each fixed packet created by the divided storage unit in place of the variable packet to another device via a communication line is provided.
The acquisition unit includes a TLV packet containing program information, receives a broadcast wave according to the MMT method from a broadcast satellite for advanced broadband satellite digital broadcasting, and demolishes the received broadcast wave to include the TLV packet. Generate a stream and
The divided storage unit creates a plurality of TS packets having a size of 188 bytes, each including data obtained by dividing the TLV packet included in the stream into 185 bytes.
The communication line is a broadcast retransmission device which is an IPTV transmission network.

[Appendix 3]
It is equipped with a receiver that receives a stream from another device from which null packets for adjusting the transmission rate have been deleted from the stream generated by demodulating the broadcast wave according to the MMT method.
The stream is a plurality of fixed packets having a predetermined size, each of which is a variable size packet containing program information and contains divided data, for adjusting the time between devices using Coordinated Universal Time. Includes the fixed packet with transmission time information that indicates the transmission side count value calibrated using the time adjustment information as the transmission timing.
further,
The receiving side clock generator that generates the receiving side reference clock,
A receiver counter that updates the receiver count value based on the receiver reference clock,
A synchronization processing unit that controls at least one of the receiving side clock generating unit and the receiving side counter by using the transmission time information added to the fixed packet is provided.
The receiver is a plurality of TS packets having a size of 188 bytes, each containing data in which a size-variable TLV packet containing information on the program is divided into 185 bytes, and is calibrated using an NTP packet. A stream containing the TS packet with a time stamp indicating the transmission side count value as a transmission timing is received from the broadcast retransmission device.
The synchronization processing unit uses the time stamp added to the TS packet to perform calibration processing for calibrating the receiving side count value in the receiving side counter, and transmitting the receiving side reference clock in the broadcast retransmission device. A broadcast receiver that performs at least one of the adjustment processes that synchronize with the side reference clock.

[Appendix 4]
The broadcast retransmission device includes a transmitting side clock generator that generates the transmitting side reference clock of 27 MHz, and a transmitting side counter that updates the transmitting side count value based on the transmitting side reference clock. The broadcast receiver described in.

[Appendix 5]
The broadcast receiving device according to Appendix 3 or Appendix 4, wherein the receiving side clock generating unit generates the receiving side reference clock of 27 MHz.

10 IPTV transmission network 11 External antenna 21 High-accuracy oscillator (transmitter clock generator)
22 Counter (sender counter)
23 Demodulation section (acquisition section)
24 NTP packet acquisition unit 25 Conversion unit (time synchronization unit)
26 Deleted part 27 TS conversion part (divided storage part)
28 TTS conversion part (additional part)
29 Blocking unit 30 IP packetizing unit 31 IP transmitting unit 41 IP receiving unit 42 Time stamp separation unit 43 Clock adjustment unit (synchronization processing unit)
44 VCO (Receiver clock generator)
45 PCR counter (reception counter)
46 Calibration section (synchronous processing section)
47 Conversion unit 48 TLV resynthesis unit 49 Decoding unit 101 Broadcast retransmission device 102 IP broadcast receiver 121 Router 122 ONU
131 STB
132 TV receiver 133 TV monitor 151 IPTV center 152 Subscriber home 301 Broadcast retransmission system

Claims (12)

An acquisition unit that acquires a stream containing null packets for adjusting the transmission rate, which is generated by demodulating a broadcast wave according to the MMT (MPEG Media Transport) method, and
A deletion unit that deletes the null packet from the stream acquired by the acquisition unit, and a deletion unit.
A broadcast retransmission device including a transmission unit that transmits the stream from which the null packet has been deleted by the deletion unit to another device via a communication line. The stream further includes variable size packets containing program information.
The broadcast retransmission device further
The variable packet includes a divided storage unit that creates a plurality of fixed packets having a predetermined size, each containing divided data.
The broadcast according to claim 1, wherein the transmitting unit transmits the stream in which the null packet is deleted by the deleting unit and the fixed packet created by the divided storage unit is included in place of the variable packet. Retransmitter. The broadcast retransmission device further
The broadcast retransmission device according to claim 2, further comprising an additional unit that adds transmission time information indicating the transmission timing of the fixed packet to the fixed packet. The stream further contains time adjustment information for time adjustment between devices.
The broadcast retransmission device further
A clock generator that generates a reference clock and
A counter that updates the count value based on the reference clock,
A time synchronization unit for calibrating the count value of the counter by using the time adjustment information included in the stream is provided.
The broadcast retransmission device according to claim 3, wherein the additional unit adds the transmission time information indicating the count value as the transmission timing to the fixed packet. An acquisition unit that acquires a stream containing variable size packets containing program information, which is generated by demodulating a broadcast wave according to the MMT method.
A divided storage unit that creates a plurality of fixed packets having a predetermined size, each of which contains divided data of the variable packet, and a divided storage unit.
A broadcast retransmission device including a transmission unit that transmits the stream including each fixed packet created by the divided storage unit in place of the variable packet to another device via a communication line. It is equipped with a receiver that receives a stream from another device from which null packets for adjusting the transmission rate have been deleted from the stream generated by demodulating the broadcast wave according to the MMT method.
The stream is a plurality of fixed packets having a predetermined size, each of which includes divided data in a variable size packet containing program information, and uses time adjustment information for time adjustment between devices. Includes a fixed packet with transmission time information that indicates the calibrated count value as the transmission timing.
further,
A clock generator that generates a reference clock and
A counter that updates the count value based on the reference clock,
A broadcast receiving device including a clock generation unit and a synchronization processing unit that controls at least one of the counters using the transmission time information added to the fixed packet. It is a broadcast retransmission method in a broadcast retransmission device.
A step to acquire a stream containing null packets for adjusting the transmission rate, which is generated by demodulating a broadcast wave according to the MMT method, and
A step of deleting the null packet from the acquired stream, and
A broadcast retransmission method comprising the step of transmitting the stream from which the null packet has been deleted to another device via a communication line. It is a broadcast retransmission method in a broadcast retransmission device.
A step of acquiring a stream containing variable size packets containing program information generated by demodulating a broadcast wave according to the MMT method, and
A step of creating a plurality of fixed packets having a predetermined size, each of which includes divided data of the variable packet included in the acquired stream, and a step of creating a plurality of fixed packets having a predetermined size.
A broadcast retransmission method comprising the step of transmitting the stream including each of the created fixed packets in place of the variable packet to another device via a communication line. A broadcast reception method in a broadcast receiver including a clock generator that generates a reference clock and a counter that updates a count value based on the reference clock.
Including the step of receiving a stream from another device from which the null packet for adjusting the transmission rate has been deleted from the stream generated by demodulating the broadcast wave according to the MMT method.
The stream is a plurality of fixed packets having a predetermined size, each of which includes divided data in a variable size packet containing program information, and uses time adjustment information for time adjustment between devices. Includes a fixed packet with transmission time information that indicates the calibrated count value as the transmission timing.
The broadcast receiving method further includes
A broadcast receiving method including a step of controlling at least one of the clock generator and the counter using the transmission time information added to the fixed packet. A broadcast retransmission program used in a broadcast retransmission device.
Computer,
An acquisition unit that acquires a stream containing null packets for adjusting the transmission rate, which is generated by demodulating a broadcast wave according to the MMT method.
A deletion unit that deletes the null packet from the stream acquired by the acquisition unit, and a deletion unit.
A transmission unit that transmits the stream from which the null packet has been deleted by the deletion unit to another device via a communication line.
Broadcast retransmission program to function as. A broadcast retransmission program used in a broadcast retransmission device.
Computer,
An acquisition unit that acquires a stream containing variable size packets containing program information, which is generated by demodulating a broadcast wave according to the MMT method.
A divided storage unit that creates a plurality of fixed packets having a predetermined size, each of which contains divided data of the variable packet.
A transmitter that transmits the stream, which includes each fixed packet created by the divided storage unit in place of the variable packet, to another device via a communication line.
Broadcast retransmission program to function as. A broadcast reception program used in a broadcast receiver including a clock generator that generates a reference clock and a counter that updates a count value based on the reference clock.
Computer,
A receiver that receives a stream from another device from which null packets for adjusting the transmission rate have been deleted from the stream generated by demodulating the broadcast wave according to the MMT method.
It is a program to function as
The stream is a plurality of fixed packets having a predetermined size, each of which includes divided data in a variable size packet containing program information, and uses time adjustment information for time adjustment between devices. Includes a fixed packet with transmission time information that indicates the calibrated count value as the transmission timing.
In addition, the computer,
A synchronization processing unit that controls at least one of the clock generation unit and the counter using the transmission time information added to the fixed packet.
Broadcast reception program to function as.

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