JP2020162090A - Transmission node, broadcast station system, control node and transmission control method - Google Patents

Abstract

To provide a device, a method and a system which, when using a protocol which transmits essence data such as video data, voice data or auxiliary data in a single stream in a broadcast station IP network, appropriately set up the transmission of the stream.SOLUTION: A transmission node 300 includes: a transmitter unit which transmits, to the broadcast station IP network, a broadcast signal stream in which different types of essence data are transmitted with a single port number; and a control unit which provides another node with an SDP (Session Description Protocol) object which describes the attribute of the broadcast signal stream. The SDP object includes, in an attribute field which described format specific parameters of a broadcast signal stream, one or more compression related information of video essence data, voice channel number information related to voice essence data and error correction information applied to the essence data.SELECTED DRAWING: Figure 20

Description

The present disclosure relates to transmission nodes, broadcasting station systems, control nodes and transmission control methods.

Many existing broadcast stations have dedicated networks for transmitting broadcast materials such as video, audio and ancillary data within the station. Various devices such as capture devices such as cameras and microphones, storage servers for storing content data, playback devices for playing back content, and gateway devices for converting the format of transmitted signals are connected to the dedicated network. .. SDI (Serial Digital Interface) has been widely used as a signal format for transmitting broadcast materials on a dedicated network.

However, as a result of the remarkable improvement in the performance of IP (Internet Protocol) technology in recent years, broadcasters have found the advantage of utilizing more versatile IP technology and are making efforts to update the network in the station to the IP network. Started. By adopting an IP-based network architecture, it is possible to construct a high-speed and large-capacity network at low cost by using network devices such as general-purpose routers and switches.

Standardization of protocols for transmitting broadcast materials using IP technology is currently underway. For example, SMPTE (Society of Motion Picture and Television Engineers) has standardized SMPTE ST2022-6, which is a protocol for transmitting SDI images, which are a mixture of video, audio, and auxiliary data, in IP packets (non-patent). Reference 1). Furthermore, SMPTE is also proceeding with the standardization of the SMPTE ST2110 series, which is a protocol group for transmitting video, audio and auxiliary data in separate streams (see Non-Patent Document 2). Among them, according to SMPTE ST2110-10, the nodes participating in the broadcasting station system synchronize with each other with high accuracy based on the mechanism of PTP (Precision Time Protocol). This high-precision synchronization makes it possible for the receiver to appropriately time the different streams transmitted along different routes on the IP network.

ARIB (Association of Radio Industries and Businesses), a standardization organization in Japan, has standardized ARIB STD-B73 as a data structure for transmitting video, audio, and auxiliary data in a single stream. (See Non-Patent Document 3).

Furthermore, in order to ensure interoperability between various devices, AMWA (Advanced Media Workflow Association) is a set of control interface standards for managing and controlling the transmission of streams between devices, NMOS (Networked). Media Open Specifications) Standards are being developed. For example, NMOS IS-04 is a control interface standard for discovery and registration of network resources (see Non-Patent Document 4). NMOS IS-05 is a control interface standard for device connection management (see Non-Patent Document 5). When the NMOS standard is used, the transmitting node provides the control node with an SDP (Session Description Protocol) object that describes the attributes of the broadcast signal stream that can be transmitted by the own node, and the control node describes the SDP object. Set up stream transmission based on.

Patent Documents 1 and 2 disclose examples of SDP objects that can be used when streaming broadcast content.

Thomas Edwards, “SMPTE ST 2022: Moving Serial Interfaces (ASI & SDI) to IP”, [online], August 17, 2017, SMPTE Standards Webcast Series, [Search February 15, 2019], Internet <URL : Https://www.smpte.org/sites/default/files/2017-08-17-ST-2022-Edwards-V4-Handout.pdf ＞ SMPTE, “SMPTE ST 2110 FAQ”, [online], [Search on February 15, 2019], Internet <URL: https://www.smpte.org/st-2110> ARIB, “Data Structure Standard for Essence Independent Single Stream RTP Datagrams in Production IP Interfaces (ARIB STD-B73 1.0 Edition)”, [online], July 26, 2018, [February 15, 2019 Sun], Internet <URL: https://www.arib.or.jp/kikaku/kikaku_hoso/desc/std-b73.html> AMWA, “AMWA IS-04 NMOS Discovery and Registration Specification (Stable)”, [online], [February 15, 2019], Internet <URL: https://amwa-tv.github.io/nmos-discovery -registration /> AMWA, “AMWA IS-05 NMOS Device Connection Management Specification”, [online], [February 15, 2019], Internet <URL: https://amwa-tv.github.io/nmos-device-connection- management />

Japanese Unexamined Patent Publication No. 2015-73197 Special Table 2007-531368 Gazette

When interrelated video, audio, and auxiliary data are transmitted in separate streams such as SMPTE ST2110, the port numbers of those streams differ at the transport layer, so the process of reconstructing the original content on the receiving side is performed. It gets complicated. If the port numbers are different, as a result of route control on the IP network, there is a possibility that each stream will receive a different delay due to the difference in the transmission route followed by each stream. On the other hand, the video, audio, and auxiliary data streams of ARIB STD-B73 do not have the problems peculiar to SMPTE ST2110 described above because they have the same port number in the transport layer. However, ARIB STD-B73 does not specify how the nodes participating in the broadcasting station system should operate cooperatively to process the stream.

For example, if high-precision synchronization is not established between the nodes involved in stream transmission and there is no agreement on the time information field that should be used for time adjustment between packets, it will be exchanged within the broadcasting station system. It is not possible to flexibly combine various essences to compose broadcast contents.

Also, the format of the SDP object normally used for the SMPTE ST2110 stream is not necessarily suitable for the characteristics of the ARIB STD-B73 stream, neither in the format structure nor in the content of the information described.

The technology according to the present disclosure aims to solve at least one of the above-mentioned problems.

From a certain point of view, a transmitter that transmits a broadcast signal stream that transmits different types of essence data with a single port number to the IP network of the broadcasting station, and an SDP (Session Description) that describes the attributes of the broadcast signal stream. The SDP object includes a control unit that provides a Protocol) object to another node, and the SDP object includes compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and essence data. A transmission node is provided that includes one or more of the error correction information indicating the error correction method applied to the above in an attribute field that describes a format-specific parameter of the broadcast signal stream.

According to another aspect, a broadcasting station system including the transmitting node and the receiving node for receiving the broadcast signal stream set up according to the description of the SDP object is provided.

From another point of view, it is a control node that controls transmission of a broadcast signal stream that transmits different types of essence data with a single port number from a transmitting node to a receiving node in the IP network of a broadcasting station. The SDP object includes a control unit that acquires an SDP (Session Description Protocol) object that describes the attributes of the broadcast signal stream from the transmission node, and the SDP object is compression-related information and audio essence indicating whether the video essence data is compressed. One or more of the number of audio channels related to the data and the error correction information indicating the error correction method applied to the essence data are included in the attribute field that describes the format-specific parameters of the broadcast signal stream. , Control nodes are provided.

From another point of view, providing an SDP (Session Description Protocol) object that describes the attributes of a broadcast signal stream that transmits different types of essence data with a single port number to other nodes, and the above broadcast signal. The SDP object includes transmission of a stream to the IP network of a broadcasting station, compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and essence data. Provided is a transmission control method that includes one or more of error correction information indicating an error correction method applied to the above in an attribute field that describes a format-specific parameter of the broadcast signal stream. A computer program that causes a processor to execute the transmission control method may be provided. A non-temporary computer-readable storage medium that stores the computer program may be provided.

From another point of view, it is a transmission control method for controlling the transmission of a broadcast signal stream that transmits different types of essence data with a single port number from a transmitting node to a receiving node in the IP network of a broadcasting station. The SDP object includes the acquisition of an SDP (Session Description Protocol) object that describes the attributes of the broadcast signal stream from the transmission node, and the SDP object is compression-related information indicating whether the video essence data is compressed. One or more of the number of audio channels related to the audio essence data and the error correction information indicating the error correction method applied to the essence data are contained in the attribute field that describes the format-specific parameters of the broadcast signal stream. The transmission control method including the above is provided. A computer program that causes a processor to execute the transmission control method may be provided. A non-temporary computer-readable storage medium that stores the computer program may be provided.

According to the technology according to the present disclosure, when using a protocol for transmitting essence data such as video data, audio data or auxiliary data in a single stream on the IP network of a broadcasting station, the transmission of the stream is appropriately set up. It becomes possible to do. It should be noted that the technique according to the present disclosure may produce other effects in place of or in combination with the effect.

It is the schematic which shows an example of the structure of the broadcasting station system which concerns on embodiment of this disclosure. It is explanatory drawing for demonstrating an example of the logical structure of the IP domain of the broadcasting station system which concerns on embodiment of this disclosure. It is explanatory drawing for demonstrating the system timing model defined by SMPTE ST2110-10. It is explanatory drawing for demonstrating the time adjustment between the video essence and the audio essence based on the system timing model explained with reference to FIG. It is explanatory drawing for demonstrating the structure of the datagram in ARIB STD-B73. It is explanatory drawing for demonstrating transmission of video essence and audio essence in a single stream according to ARIB STD-B73. It is a block diagram which shows an example of the structure of the broadcast signal processing node which concerns on 1st Embodiment. It is a block diagram which shows an example of the detailed structure of the received stream processing part shown in FIG. 7. It is explanatory drawing for demonstrating the 1st example of the method for time adjustment of the essence data between two RTP packets. It is explanatory drawing for demonstrating the 2nd example of the method for time adjustment of the essence data between two RTP packets. It is explanatory drawing for demonstrating the 3rd example of the method for time adjustment of the essence data between two RTP packets. It is explanatory drawing for demonstrating the 4th example of the method for time adjustment of the essence data between two RTP packets. It is a flowchart which shows an example of the flow of the stream transmission processing which concerns on 1st Embodiment. It is a flowchart which shows an example of the flow of stream reception processing which concerns on 1st Embodiment. It is a block diagram which shows an example of the structure of the broadcast signal processing node which concerns on 2nd Embodiment. It is a block diagram which shows an example of the structure of the broadcast signal processing node which concerns on 1st modification of 2nd Embodiment. It is a block diagram which shows an example of the structure of the broadcast signal processing node which concerns on the 2nd modification of 2nd Embodiment. It is explanatory drawing for demonstrating the typical format structure of the SDP object for an essence separated stream. It is explanatory drawing which shows an example of the SDP object which described the attribute of the SMPTE ST2110 stream which has the format structure described with reference to FIG. It is explanatory drawing for demonstrating the format structure of the SDP object defined for the essence mixed stream in 3rd Embodiment. It is explanatory drawing which shows an example of the SDP object which described the attribute of ARIB STD-B73 stream which has the format structure described with reference to FIG. It is a block diagram which shows an example of the schematic structure of the broadcasting station system which concerns on 3rd Embodiment. It is a block diagram which shows an example of the structure of the transmission node which concerns on 3rd Embodiment. It is a flowchart which shows 1st example of the flow of the transmission control processing which can be executed by the transmission node shown in FIG. It is a flowchart which shows the 2nd example of the flow of the transmission control processing which can be executed by the transmission node shown in FIG. It is a block diagram which shows an example of the structure of the control node which concerns on 3rd Embodiment. FIG. 5 is a flowchart showing a first example of a flow of transmission control processing that can be executed by the control node shown in FIG. 23. It is a flowchart which shows the 2nd example of the flow of the transmission control processing which can be executed by the control node shown in FIG. It is a block diagram which shows an example of the structure of the transmission node which concerns on 4th Embodiment. It is a block diagram which shows an example of the structure of the control node which concerns on 4th Embodiment.

Hereinafter, embodiments of the technique according to the present disclosure will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, elements that can be similarly described may be designated by the same reference numerals, so that duplicate description may be omitted.

The explanation is given in the following order.
1. 1. Overview 2. First Embodiment 2-1. Configuration example of broadcast signal processing node 2-2. Detailed configuration example of the receive stream processing unit 2-3. Process flow 3. Second Embodiment 3-1. Configuration example of broadcast signal processing node 3-2. Modification example 4. Summary of the first embodiment and the second embodiment 5. Third Embodiment 5-1. Examples of existing SDP objects 5-2. New format for SDP objects 5-3. Configuration example of broadcasting station system 5-4. Configuration example of transmitting node 5-5. Control node configuration example 6. Fourth Embodiment 6-1. Configuration example of transmitting node 6-2. Control node configuration example 7. Summary of the third embodiment and the fourth embodiment

<< 1. Overview >>
First, with reference to FIG. 1, an outline of a broadcasting station system to which some embodiments of the present disclosure can be applied will be described. FIG. 1 is a schematic view showing an example of the configuration of the broadcasting station system 1 according to the embodiment of the present disclosure. Referring to FIG. 1, the broadcasting station system 1 includes one or more network devices 12, a camera 20a, a monitor 20b, an IP gateway 20c, an IP gateway 20d, a camera 22, a microphone 24, a data server 26, and an integrated playout. ) 32, monitor 34, APS (Automatic Program control System) 40, and control terminal 50. The network device 12, the camera 20a, the monitor 20b, the IP gateway 20c, the IP gateway 20d, the APS 40, and the control terminal 50 belong to the IP domain 10.

(1) Description of Various Devices The network device 12 is a device in charge of transferring a stream in an IP network. Each of the network devices 12 may be any type of network device, such as a router, switch, bridge or repeater. Each of the network devices 12 may be a general-purpose product (also referred to as COTS (Commercial Off-The-Shelf)) that can be introduced at low cost. Although six network devices 12 are shown in FIG. 1, the broadcasting station system 1 may include any number of network devices 12 without being limited to such an example. The IP domain 10 may be composed of a single network or may include a plurality of subnetworks.

The camera 20a is a type of capture device that produces broadcast material. For example, the camera 20a captures some object and generates video data. The camera 20a may acquire voice through a built-in microphone and generate voice data. The camera 20a belongs to the IP domain 10 and can packetize a data stream of video data and audio data into a series of IP packets and transmit the data stream to an IP network.

The monitor 20b is a type of playback device that receives broadcast material and reproduces content. For example, the monitor 20b receives the video data and reproduces the video. The monitor 20b may receive the audio data and reproduce the audio. The monitor 20b may receive the auxiliary data to be additionally transmitted and process the auxiliary data (for example, play subtitles). The monitor 20b may provide the user with an editing function for editing the content. The monitor 20b belongs to the IP domain 10 and can receive a series of IP packets transferred on the IP network.

The IP gateway 20c is a gateway device located at the boundary between the IP domain 10 and another signal domain. The IP gateway 20c connects to one or more network devices 12. In the example of FIG. 1, a camera 22, a microphone 24, and a data server 26 are further connected to the IP gateway 20c. For example, the IP gateway 20c may receive an SDI signal carrying video data from the camera 22. Further, the IP gateway 20c can receive an SDI signal for carrying voice data from the microphone 24. Further, the IP gateway 20c can receive an SDI signal that carries one or more of video data, audio data, and auxiliary data from the data server 26. The signal format of the signal transmitted outside the IP domain 10 may be any derivative of SDI such as SD-SDI, HD-SDI, 3G-SDI, 6G-SDI or 12G-SDI, or , A signal format other than SDI may be used. As described above, the IP gateway 20c multiplexes or demultiplexes the signals that carry the broadcast material received from the camera 22, the microphone 24, and the data server 26 as necessary, and then packets them into a series of IP packets. Can be sent to the IP network.

The IP gateway 20d is also a gateway device located at the boundary between the IP domain 10 and other signal domains. The IP gateway 20d connects to one or more network devices 12. In the example of FIG. 1, the integrated playout 32 and the monitor 34 are further connected to the IP gateway 20d. For example, the IP gateway 20d receives IP packets transferred on the IP network, converts the IP packets into SDI signals (or signals in other signal formats), and is one of the integrated playout 32 and the monitor 34. Or it can be sent to both parties. As a matter of course, the IP gateway 20c may have a function of converting an IP packet into an SDI signal in the same manner as the IP gateway 20d. Further, the IP gateway 20d may have a function of converting an SDI signal into an IP packet in the same manner as the IP gateway 20c.

The APS 40 is a system that advances the broadcasting of a television program according to a predetermined schedule. For example, the APS 40 sends a control message to the IP network to transmit a data stream output from a given source (eg, a camera and microphone, or a data server) to the integrated playout 32 at a given time. Upon receiving the data stream, the integrated playout 32 transmits a broadcast signal of the television program to the antenna through the line of the broadcasting station. The data stream is also distributed to, for example, the monitor 20b or the monitor 34, and the broadcast content can be reproduced in the broadcasting station.

The control terminal 50 is a terminal device that provides a user with a user interface related to the management and control of nodes included in the broadcasting station system 1. The control terminal 50 may be a user terminal dedicated to the broadcasting station system 1, or may be a general-purpose terminal such as a PC (Personal Computer) or a smartphone. For example, the control terminal 50 acquires setting information related to transmission of a stream on a network in a broadcasting station via a user interface and registers it in a database in the system. Further, the control terminal 50 receives, for example, a request for transmission of a stream between a given node via a user interface.

(2) IP Multicast The transmission of the broadcast signal stream in the IP domain 10 of the broadcasting station system 1 is typically performed by multicast. The source IP address of the packet to be multicast is the IP address of the transmitting node, and the destination IP address is a multicast address belonging to a specific address range. A set of nodes that receive multicast packets addressed to individual multicast addresses is called a multicast group, and multicast addresses are also called group addresses. A receiving node that intends to receive a stream sends a message (for example, IGMP (Internet Group Management Protocol) JOIN) notifying that it joins a multicast group corresponding to the stream to a nearby router. Then, messages are exchanged between the routers to update the multicast tree, and the stream transmitted from the specific transmitting node is delivered to the receiving node via the IP network. When the receiving node ends receiving the multicast stream, it sends a message notifying the leave from the multicast group to a nearby router. The technique according to the present disclosure is not limited to the above-mentioned example, and can be applied to a case where a stream is transmitted by unicast.

(3) Example of Logical Configuration of IP Domain FIG. 2 shows an example of the logical configuration of the IP domain 10 of the broadcasting station system 1 shown in FIG. 1 (for simplicity, here, APS40 and control). Terminal 50 is omitted). Referring to FIG. 2, the first node corresponding to the camera 20a includes a sender 60a. A "sender" is a functional entity that has the ability to send a stream. The second node corresponding to the IP gateway 20c includes senders 60b, 60c and 60d. The senders 60b, 60c and 60d may correspond to the devices that are the sources of the individual streams housed by the IP gateway 20c. The third node corresponding to the monitor 20b includes the receiver 65a. A "receiver" is a functional entity capable of receiving a stream. The fourth node corresponding to the IP gateway 20d includes receivers 65b and 65c. The receivers 65b and 65c may correspond to devices to which the individual streams housed by the IP gateway 20d are received.

As can be understood from the above description, one node (which may be called a "card") represents one physical entity. Not limited to the example of FIG. 1, one node may include any number of senders and / or any number of receivers as functional entities. In addition, a logical unit (for example, see the broken line frame in the figure) including a plurality of functional entities may be defined in one node (for example, one device housed in one IP gateway is a plurality of devices). (Case of sending or receiving a stream of). For example, the NMOS being studied by the AMWA, given such a logical system model, specifies application protocol interfaces (APIs) for managing and controlling the transmission of streams in the IP domain.

In the present specification, when it is not necessary to distinguish the nodes 20a, 20b, 20c and 20d from each other, these are collectively referred to as the node 20 by omitting the alphabet at the end of the code. The same applies to the codes of the senders 60a, 60b, 60c, 60d (sender 60) and the receivers 65a, 65b, 65c (receiver 65), and other components.

(4) Essence and Stream As described above, the content of a television program is generally composed of three types of broadcast material data: video data, audio data, and auxiliary data. In this specification, the term "essence" is used to distinguish the types of broadcast materials and refer to the components of these contents. In other words, the essence is a broadcast material expressed as data. When attempting to transmit an essence over an IP network, the essence is converted into a digital signal and packetized according to some IP-based protocol. A common port number is assigned to each stream in a series of IP packets that carry the essence. That is, the stream can be a sequence of IP packets that have a common IP address and port number. Regardless of which protocol described below is used as the IP-based stream transmission protocol, packets are usually transmitted according to RTP (Real-time Transport Protocol) at the application layer and UDP (User Datagram Protocol) at the transport layer. To.

(5) IP-based stream transmission protocol One of the typical protocols for IP-based stream transmission is SMPTE ST2022-6. SMPTE ST2022-6 maps the SDI signal as it is to the IP packet. As such, a single ST2022-6 stream contains different types of essences and data corresponding to the blanking period. The ST2022-6 stream may be suitable for transitional broadcaster systems where IP and SDI domains coexist.

Another typical protocol for IP-based stream transmission is SMPTE ST2110. SMPTE ST2110 maps different types of essences to different streams. Therefore, a single stream contains only a single type of essence, and no stream contains data corresponding to the blanking period. SMPTE ST2110-10 defines a method for high-precision synchronization between nodes participating in a broadcasting station system based on the mechanism of PTP. SMPTE ST2110-20 defines a transmission format for uncompressed video essence. SMPTE ST2110-21 defines a method for traffic shaping of video essence. SMPTE ST2110-30 defines a transmission format for uncompressed PCM audio essence. SMPTE ST2110-31 defines a transmission format for AES3 audio essence. SMPTE ST2110-40 defines a transmission format for auxiliary data essences. In the SMPTE ST2110 series, compression of video essence is not supported, and error correction coding / decoding is not performed.

(6) Time synchronization in SMPTE ST2110-10 In order to broadcast a television program according to an accurate schedule, it is necessary for a node in the system to recognize the accurate time. Also, when multiplexing streams received from multiple different nodes, synthesizing multiple videos, or playing back video and audio at the same time, it is important that fine time synchronization is established between the nodes. It takes. FIG. 3 is an explanatory diagram for explaining a system timing model defined by SMPTE ST2110-10 for the purpose of such time synchronization.

FIG. 3 shows, as an example, the nodes 20a and 20b of the broadcasting station system 1, and the common reference clock 70. The common reference clock 70 synchronizes with a highly accurate time source (for example, a GNSS (Global Navigation Satellite System) satellite such as a GPS (Global Positioning System) satellite) and operates as a so-called PTP grand master. The common reference clock 70 delivers a synchronization message to slave nodes in the system according to the PTP mechanism.

Node 20a is a slave node of PTP. The node 20a synchronizes its device internal clock 72a with the common reference clock 70, and maintains the synchronization (for example, adjusts the delay) based on the synchronization message received from the common reference clock 70. The video media clock 73a of the node 20a is locked by the device internal clock 72a and travels at a frequency peculiar to the video. The audio media clock 76a is locked by the device internal clock 72a and travels at an audio-specific frequency. The video-specific frequency defined by SMPTE ST2110-20 is 90 kHz, and the audio-specific frequency defined by SMPTE ST2110-30 is 48 kHz.

Normally, the RTP packet is given a time stamp having an offset randomly generated with respect to the media clock, but in SMPTE ST2110-10, the offset is set to zero. This allows for a quick recovery of stream transmission if the sender restarts due to some failure (because the process for determining the random offset is omitted). That is, the video RTP clock 74a of the node 20a has no offset with respect to the video media clock 73a and shows the same time as the video media clock 73a. Then, an RTP time stamp is added to the RTP header of each packet of the RTP stream of the video essence transmitted by the node 20a according to the video RTP clock 74a. Similarly, the audio RTP clock 77a of the node 20a has no offset with respect to the audio media clock 76a and shows the same time as the audio media clock 76a. Then, an RTP time stamp is added to the RTP header of each packet of the RTP stream of the voice essence transmitted by the node 20a according to the voice RTP clock 77a.

Generally speaking, in SMPTE ST2110-10, a device that captures video or audio assigns a capture time as an RTP time stamp to each packet. The device that plays back the content from the storage assigns the output time of the essence from the communication interface to each packet as an RTP time stamp. The device that converts the SDI signal into an IP packet assigns the clock value of the SDI signal at the time of alignment to each packet as an RTP time stamp.

Node 20b is also a slave node of PTP. The node 20b synchronizes its device internal clock 72b with the common reference clock 70, and maintains the synchronization (for example, adjusts the delay) based on the synchronization message received from the common reference clock 70. Although not shown in the figure, like the node 20a, the node 20b also has a media clock locked by the device internal clock 72b and an RTP clock having no offset with respect to the media clock. The node 20b receives, for example, the RTP stream of the video essence and the RTP stream of the audio essence transmitted from the node 20a at different port numbers. Then, the node 20b performs time alignment between packets based on its own RTP clock and the RTP time stamp given to the RTP header of each packet of the received RTP stream. Such a mechanism utilizing PTP enables highly accurate time synchronization with an error of 10 μs or less between the nodes participating in the IP network of the broadcasting station.

FIG. 4 is an explanatory diagram for explaining the time adjustment between the video essence and the audio essence based on the system timing model of SMPTE ST2110-10 described with reference to FIG. Referring to FIG. 4, the node 20a transmits the RTP stream 81 of the video essence and the RTP stream 82 of the audio essence to the network in parallel. Each of the packets (V ₁ , V ₂ , V ₃ , ...) Contained in the RTP stream 81 has an RTP time stamp and a sequence number assigned according to the video RTP clock in the RTP header. Each of the packets (A ₁ , A ₂ , A ₃ , ...) Contained in the RTP stream 82 has an RTP time stamp and a sequence number assigned according to the voice RTP clock in the RTP header. Node 20b, in UDP port _{P V,} receives a sequence of RTP packets in RTP streams 81, processes the received RTP packet to the sequence number order. The node 20b is in UDP port _{P A,} receives a sequence of RTP packets in RTP streams 82, processes the received RTP packet to the sequence number order. For example, when the node 20b tries to reproduce the video and audio synchronously, the node 20b compares the RTP time stamp of each packet of the RTP stream 81 with the RTP time stamp of each packet of the RTP stream 82, and reproduces the video and audio. Synchronize the times (eg, frame timing) with each other. It should be noted that the time adjustment between the plurality of video essences, between the plurality of audio essences, and between the video essence or the audio essence and the auxiliary data essence can be similarly performed.

(7) ARIB STD-B73
When interrelated video, audio, and auxiliary data are transmitted in separate streams such as SMPTE ST2110, the port numbers of those streams differ at the transport layer, so the process of reconstructing the original content on the receiving side is performed. It gets complicated. If the port numbers are different, as a result of route control on the IP network, there is a possibility that each stream will receive a different delay due to the difference in the transmission route followed by each stream. In order to eliminate these inconveniences, ARIB, a standardization organization in Japan, has standardized ARIB STD-B73 as a data structure for transmitting video, audio, and auxiliary data in a single stream. ..

FIG. 5 is an explanatory diagram for explaining the structure of the datagram described in Chapter 2 of ARIB STD-B73 1.0 version. The datagram shown in the thick line frame in FIG. 5 constitutes one packet together with the preceding network header and the succeeding FCS (Frame Check Sequence). Network headers include, for example, MAC (Medium Access Control) headers (eg, Ethernet headers), IP headers and UDP headers. The RTP datagram for essence data includes a transport header including an RTP header and a common header, an essence header, and an essence payload. The essence datagram includes an essence header and an essence payload. The part including the common header, the essence header and the essence payload is also referred to as an RTP payload. On the other hand, although not shown in the figure, the RTP datagram for FEC data includes the FEC payload instead of the essence header and essence payload. It should be noted that the terms packet and datagram are used interchangeably herein. The meaning of these terms will be readily understood by those skilled in the art.

The RTP header includes, for example, "payload type", "sequence number" and "timestamp" as data items. A fixed value (for example, 110) is set for the "payload type". The value of the "sequence number" is incremented by 1 for each transmission. Its initial value can be set randomly. Although the "timestamp" value is monotonically and linearly incremented, ARIB STD-B73 1.0 edition stipulates that this field should not be used synchronously.

The common header includes, for example, "frame count", "datagram type" and "sequence number" as data items. The same value as the "frame count" of the corresponding essence header is set in the "frame count" of the common header. A value indicating whether the corresponding datagram is an essence datagram or an FEC (Forward Error Correction) datagram is set in the "datagram type". The value of the "sequence number" is separately incremented by 1 for each transmission in the video essence, audio essence and auxiliary data essence (and FEC). Its initial value can be set randomly.

The essence header includes, for example, "payload type" and "frame count" as data items. In the "payload type", a value indicating the type of essence contained in the subsequent essence payload is set (0: video, 1: audio, 2: auxiliary data, etc.). The "frame count" of the essence header is set to a value for synchronizing the datagram of each essence on the receiving side. The epoch time defined in SMPTE ST2057-1 is used as the initial value zero of the "frame count". The value of "frame count" is incremented by 1 each time a new video frame is started, and the same value is set for all essence datagrams belonging to the same video frame.

FIG. 6 is an explanatory diagram for explaining transmission of video essence and audio essence in a single stream according to ARIB STD-B73. Referring to FIG. 6, node 20c sends an RTP stream 83 containing both a packet for video essence and a packet for audio essence to the network. Each of the packets (V ₁ , A ₁ , V ₂ , A ₂ , ...) Contained in the RTP stream 83 has a frame count value in the essence header. Node 20d, in a single port _{P M,} receives a sequence of RTP packets in RTP streams 83, processes the received RTP packet to the sequence number order. As described above, according to ARIB STD-B73, a group of RTP packets arranged one after the other in the order of sequence numbers in the RTP header belong to the same video frame and have the same frame count value. Therefore, the node 20d can synchronously process the group of RTP packets including the video essence and the audio essence.

However, ARIB STD-B73 does not specify how the nodes participating in the broadcasting station system should operate cooperatively to process the stream.

For example, if high-precision synchronization is not established between the nodes involved in stream transmission and there is no agreement on the time information field that should be used for time adjustment between packets, it will be exchanged within the broadcasting station system. It is not possible to flexibly combine various essences to compose broadcast contents. Therefore, in the first embodiment and the second embodiment described later, a protocol (for example, ARIB STD-) for transmitting essence data such as video data, audio data, or auxiliary data in a single stream on the IP network of a broadcasting station. When using B73), we propose a mechanism for appropriately adjusting the time of essence data.

In addition, the format of the SDP object commonly used for SMPTE ST2110 streams is not always suitable for the characteristics of ARIB STD-B73 streams, neither in the format structure nor in the content of the information described. Therefore, in the third embodiment and the fourth embodiment described later, when using a protocol for transmitting essence data such as video data, audio data, or auxiliary data in a single stream on the IP network of a broadcasting station, A technique that makes it possible to properly set up the transmission of the stream will be described.

In the present specification, a stream in which different types of essence data are transmitted as a single stream is also referred to as an essence mixed stream. Examples of mixed essence streams include ARIB STD-B73 streams and SMPTE ST2022-6 streams. Further, in the present specification, a stream in which different types of essence data are transmitted in different streams is also referred to as an essence-separated stream. Examples of essence-separated streams include SMPTE ST2110 streams.

<< 2. First Embodiment >>
The broadcast signal processing node 100 described in this chapter includes the functionality of both the sender 60 and the receiver 65 described above. However, as will be apparent to those skilled in the art, the functionality of one of the sender 60 and the receiver 65 may be omitted in the broadcast signal processing node 100. The broadcast signal processing node 100 may correspond to any of the nodes 20a to 20d described with reference to, for example, FIGS. 1 and 2 in the broadcasting station system 1.

<2-1. Broadcast signal processing node configuration example>
FIG. 7 is a block diagram showing an example of the configuration of the broadcast signal processing node 100 according to the first embodiment. Referring to FIG. 7, the broadcast signal processing node 100 includes a device internal clock 110, a media clock 112, an RTP clock 114, a PTP processing unit 116, a communication unit 120, a transmission stream processing unit 130, a reception stream processing unit 140, and a data processing unit. It includes 180 and a control unit 190.

(1) Device Internal Clock The device internal clock (also referred to as the device internal clock) 110 is a unique internal clock held by the broadcast signal processing node 100. In this embodiment, the device internal clock 110 synchronizes directly or indirectly with the PTP time source. Typically, when the broadcast signal processing node 100 is a PTP slave, the device internal clock 110 indirectly synchronizes with the PTP time source via the PTP ground master. On the other hand, when the broadcast signal processing node 100 is the PTP master, the device internal clock 110 is directly synchronized with the PTP time source. For example, the control unit 190, which will be described later, may set itself so that the broadcast signal processing node 100 does not become the PTP master.

(2) Media Clock The media clock 112 is a clock used for processing (for example, sampling and reconstructing) a digital media signal. In this embodiment, the media clock 112 uses the epoch time defined in SMPTE ST2057-1 as the initial value zero, is frequency-locked to the device internal clock 110, and proceeds at an accurate rate. When the broadcast signal processing node 100 cannot acquire the common reference clock and is operating on the local time base, the best available time source is based on the above epoch defined in SMPTE ST2059.1. Can be used for the media clock 112 and the RTP clock 114 described below.

In this embodiment, the broadcast signal processing node 100 supports ARIB STD-B73, which is a transmission protocol for transmitting different types of essence data in a single stream. In ARIB STD-B73, the timing of each of the video essence, the audio essence, and the auxiliary data essence is associated with the video frame. In this case, the media clock on which the RTP time stamp is based may be single regardless of the type of essence data. The same applies to the RTP clock 114 described later.

In SMPTE ST2110-20, the media clock frequency for video essence is defined as 90 kHz. On the other hand, many existing broadcasting devices have a clock of 27.0 MHz. SMPTE ST2022-8, which is being considered for integrating SMPTE ST2022-6 streams transmitting SDI images into SMPTE ST2110-10 systems, specifies a media clock frequency of 27.0 MHz. When the media clock frequency is 90 kHz, the frequency is not an integral multiple of 60 / 1.001 Hz, which is often used as the frequency of a video frame. On the other hand, when the media clock frequency is 27.0 MHz, the frequency is an integral multiple of 60 / 1.001 Hz. In consideration of this point, in the present embodiment, 27.0 MHz, which is advantageous in terms of handling in that the frame period is accurately constant and the clock value is monotonically increased, is used as the clock frequency of the media clock 112.

(3) RTP clock The RTP clock 114 is a clock that is the basis of a time stamp given to the RTP header of an RTP packet. In this embodiment, the RTP clock 114 shall have no offset with respect to the media clock 112 in accordance with the provisions of SMPTE ST2110-10. That is, the RTP clock 114 has the same value as the associated media clock 112. Therefore, in the present embodiment, the clock frequency of the RTP clock 114 is equal to 27.0 MHz, similar to the clock frequency of the media clock 112.

(4) PTP processing unit In the present embodiment, the broadcast signal processing node 100 supports, for example, the PTP profile of SMPTE ST2059-2. Then, the PTP processing unit 116 exchanges a synchronization message with the PTP master (for example, the common reference clock 70 described with reference to FIG. 3) via the communication unit 120, so that the PTP time of the device internal clock 110 Keep in sync with the source. As a result, the broadcast signal processing node 100 can operate synchronously with high accuracy with another node having a clock synchronized with the PTP time source.

(5) Communication unit The communication unit 120 is an interface that mediates communication between the broadcast signal processing node 100 and other nodes. The communication unit 120 may include a connection terminal and a connection circuit for wired communication, or may include an antenna, an RF (Radio Frequency) circuit, and a baseband circuit for wireless communication. In the present embodiment, the communication unit 120 includes a transmission unit 122 and a reception unit 124.

A series of RTP packets for a broadcast signal stream generated by a transmission stream processing unit 130, which will be described later, is input to the transmission unit 122. Each RTP packet contains essence data corresponding to any one of video data, audio data and auxiliary data in the RTP payload. The RTP header of each RTP packet is given an RTP time stamp according to the RTP clock 114 having no offset with respect to the media clock 112 locked by the device internal clock 110. The transmission unit 122 adds a network header to each input RTP packet, and transmits each packet to another node participating in the broadcasting station system 1. When the stream is an ARIB STD-B73 stream, the port number described in the network header is common to a packet for carrying video data, a packet for carrying voice data, and a packet for carrying auxiliary data.

The reception unit 124 receives a broadcast signal stream composed of a series of RTP packets from another node having a sender function similar to the transmission stream processing unit 130 and the transmission unit 122 of the broadcast signal processing node 100. Each RTP packet contains essence data corresponding to any one of video data, audio data and auxiliary data in the RTP payload. When the stream is an ARIB STD-B73 stream, a series of RTP packets is received as a single stream via a common port number. The RTP header of each RTP packet contains an RTP time stamp given according to the RTP clock having no offset to the media clock locked to the device internal clock of the transmitting node. The header in the RTP payload of each RTP packet contains frame count information based on the same RTP clock. The broadcast signal processing node 100 and the transmitting node are directly or indirectly synchronized with the PTP time source as described above. Therefore, the clock error between these nodes can be, for example, 10 μsec or less.

The receiving unit 124 may receive a broadcast signal stream other than the ARIB STD-B73 stream from another node. For example, the receiving unit 124 may receive an essence mixed stream similar to the ARIB STD-B73 stream (for example, SMPTE ST2022-6 stream). In addition, the receiving unit 124 may receive an essence-separated stream such as the SMPTE ST2110 stream.

The receiving unit 124 removes the network header from each packet of the received broadcast signal stream, and outputs the RTP packet including the RTP header and the RTP payload to the receiving stream processing unit 140.

(6) Transmission Stream Processing Unit The transmission stream processing unit 130 processes a sequence of video data, audio data, or auxiliary data input from the data processing unit 180 to generate a series of RTP packets for the broadcast signal stream. .. The transmission stream processing unit 130, for example, segments the input data sequence into one or more essence payloads and adds an essence header to each payload. The payload type in the essence header is set to a value indicating the corresponding essence type, and the frame count value is incremented by 1 each time a new video frame starts. The transmission stream processing unit 130 further adds a transport header (common header and RTP header) to each packet. The value of the sequence number in the common header is separately incremented by 1 for each transmission of the video essence, the audio essence, and the auxiliary data essence. The payload type in the RTP header is set to a fixed value, and the sequence number value is incremented by 1 for each transmission regardless of the payload type. The transmission stream processing unit 130 further adds an RTP time stamp to the RTP header according to the RTP clock 114. The transmission stream processing unit 130 outputs a series of RTP packets generated in this way to the transmission unit 122.

(7) Receive stream processing unit The reception stream processing unit 140 processes a series of RTP packets of a broadcast signal stream received from another node via the reception unit 124, and restores video data, audio data, or auxiliary data. To do. Then, the reception stream processing unit 140 outputs the restored sequence of data to the data processing unit 180. In particular, in the present embodiment, the receive stream processing unit 140 receives an RTP time stamp obtained from the RTP header of the received RTP packet, or a header in the RTP payload of the received RTP packet (for example, an essence header or a common one). Based on the frame count information acquired from the header), the essence data is timed between the RTP packet and another RTP packet. An example of a more detailed configuration of the reception stream processing unit 140 for such time adjustment will be further described later.

(8) Data processing unit The data processing unit 180 generates video data, audio data, or auxiliary data, and outputs a sequence of the generated data to the transmission stream processing unit 130. For example, the data processing unit 180 may compress video data input from a data source (not shown) to generate compressed video data. In addition, the data processing unit 180 processes video data, audio data, or auxiliary data restored by the reception stream processing unit 140. The data processing unit 180 may include, for example, two or more of a plurality of essences (eg, video essence, audio essence, and auxiliary data essence) based on essence data restored by reception stream processing unit 140 and timed with each other. Alternatively, a plurality of video essences, etc.) may be reproduced synchronously. Further, the data processing unit 180 may record the video data, audio data, or auxiliary data restored by the reception stream processing unit 140 on a recording medium (not shown) in a predetermined file format. Further, when the video data input from the reception stream processing unit 140 is compressed video data, the data processing unit 180 decompresses the compressed video data and restores the original video data. You may.

(9) Control unit The control unit 190 controls the overall operation of the broadcast signal processing node 100 as described above. The control unit 190 causes the broadcast signal stream to be transmitted from the transmission unit 122 or the broadcast signal stream to be received by the reception unit 124 in response to an instruction received from an external device such as the APS 40 or the control terminal 50. When the broadcast signal processing node 100 supports a plurality of transmission protocols, the control unit 190 causes each processing unit to perform an operation for the transmission protocol selected by, for example, an instruction from an external device. The control unit 190 notifies other nodes via the communication unit 120 of the functionality of the broadcast signal processing node 100 (for example, supported protocols, types of essences that can be transmitted / received, clock frequency and other attributes). You may.

In some embodiments described herein, the attributes of the broadcast signal stream, which is an RTP stream, are described in the SDP object. According to SMPTE ST2110-10, devices containing one or more senders construct one SDP object for each RTP stream. Also in this embodiment, an SDP object that describes the attributes of the stream that can be transmitted by the transmission stream processing unit 130 and the transmission unit 122 that have a role as a sender is stored in the storage unit (not shown) of the broadcast signal processing node 100 in advance. Can be remembered. Then, the control unit 190 provides the SDP object to the external device via a predefined application protocol interface for management (for example, an NMOS API) prior to the start of transmission of the stream. On the other hand, when the control unit 190 causes the reception unit 124 and the reception stream processing unit 140 to receive the broadcast signal stream from another transmission node, the control unit 190 sets the received broadcast signal stream according to the description of the SDP object provided by the transmission node. Configure the processing on the receiving side so that it can be processed correctly. The format of the SDP object suitable for the characteristics of the ARIB STD-B73 stream will be described in detail in the third and fourth embodiments described later.

<2-2. Detailed configuration example of the receive stream processing unit>
FIG. 8 is a block diagram showing an example of a detailed configuration of the reception stream processing unit 140 shown in FIG. 7. Referring to FIG. 8, the receive stream processing unit 140 includes a transport processing unit 142, an essence datagram processing unit 150, and an FEC datagram processing unit 170.

(1) Transport processing unit The transport processing unit 142 includes a transport header (TH) removing unit 144. The TH removing unit 144 removes the head RTP header and the common header (that is, the transport header) of the RTP packet of the broadcast signal stream input from the receiving unit 124. Then, the TH removal unit 144 distributes the datagram of the RTP packet to the essence datagram processing unit 150 or the FEC datagram processing unit 170, depending on the value of the "datagram type" in the common header. For example, when the value of "datagram type" indicates an essence datagram, the essence datagram is output to the essence datagram processing unit 150. On the other hand, when the value of the "datagram type" indicates an FEC datagram, the FEC datagram is output to the FEC datagram processing unit 170.

The output of datagrams from the transport processing unit 142 to the essence datagram processing unit 150 or the FEC datagram processing unit 170 may be performed in the order of "sequence number" in the RTP header. Processing of the datagram corresponding to the missing sequence number may be skipped. The transport processing unit 142 outputs the value of the RTP time stamp in the RTP header corresponding to the essence datagram to the alignment unit 160.

(2) Essence datagram processing unit The essence datagram processing unit 150 includes an essence header (EH) removing unit 152, a video essence processing unit 154, an audio essence processing unit 156, an auxiliary data essence processing unit 158, and an alignment unit 160. ..

The EH removing unit 152 removes the essence header at the beginning of the essence datagram input from the transport processing unit 142. Then, the EH removing unit 152 uses the essence payload of the essence datagram as the video essence processing unit 154, the audio essence processing unit 156, or the auxiliary data essence processing unit, depending on the value of the "payload type" in the essence header. Distribute to 158. For example, when the value of "payload type" indicates a video essence, the video essence is output to the video essence processing unit 154. When the value of "payload type" indicates a voice essence, the voice essence is output to the voice essence processing unit 156. When the value of "payload type" indicates an auxiliary data essence, the auxiliary data essence is output to the auxiliary data essence processing unit 158. Further, the EH removing unit 152 outputs the value of the "frame count" in the essence header to the alignment unit 160.

The video essence processing unit 154 processes the video essences sequentially input from the EH removing unit 152 to restore the video data. For example, when the ARIB STD-B73 stream is received, the video essence processing unit 154 can reverse pack the video essence according to the packing format of the video payload defined by the ARIB STD-B73 and restore the video data. .. When the video essence includes compressed video data, the video essence processing unit 154 may decompress the video essence to restore the video data (reverse compression is performed by the data processing unit 180 as described above. May be done).

The voice essence processing unit 156 processes the voice essences sequentially input from the EH removing unit 152 to restore the voice data. For example, when the ARIB STD-B73 stream is received, the audio essence processing unit 156 can reverse-pack the audio essence according to the audio payload packing format specified by ARIB STD-B73 and restore the audio data. ..

The auxiliary data essence processing unit 158 processes the auxiliary data essences sequentially input from the EH removing unit 152 to restore the auxiliary data. For example, when the ARIB STD-B73 stream is received, the auxiliary data essence processing unit 158 reverse-packs the auxiliary data essence according to the packing format of the auxiliary data payload specified by the ARIB STD-B73 to obtain the auxiliary data. Can be restored.

The alignment unit 160 is between the essence data based on the RTP time stamp acquired from the RTP header of each RTP packet in the transport processing unit 142 or the frame count information acquired from the header in the RTP payload of each RTP packet. Adjust the time.

In this embodiment, at least the first RTP packet is a packet generated according to the protocol for the essence mixed stream. The protocol for the essence mixed stream may be, for example, ARIB STD-B73. When ARIB STD-B73 is used, each RTP packet of the essence mixed stream does not include data corresponding to the blanking period, and essence data corresponding to any of video data, audio data and auxiliary data. Is included in the RTP payload.

FIG. 9A is an explanatory diagram for explaining a first example of a method for timing the essence data between two RTP packets. FIG. 9A shows the first RTP packet 161a and the second RTP packet 166a. It is assumed that the first RTP packet 161a and the second RTP packet 166a are both generated according to ARIB STD-B73. First RTP packet 161a and the second RTP packet 166a is received through a single port _{P M.}

The first RTP packet 161a includes a "time stamp" in the RTP header 162a and a "payload type" and a "frame count" in the essence header 163a. The "payload type" value of the essence header 163a indicates that the corresponding essence payload contains the video essence, and the "frame count" indicates the value F1. The value F1 corresponds to, for example, the capture time of the video frame to which the video essence belongs when the epoch time defined in SMPTE ST2057-1 is set to zero.

The second RTP packet 166a includes a "timestamp" in the RTP header 167a and a "payload type" and a "frame count" in the essence header 168a. The "payload type" value of the essence header 168a indicates that the corresponding essence payload contains audio essence, and the "frame count" indicates the value F1. The value F1 corresponds to, for example, the capture time of the video frame to which the audio essence belongs when the epoch time defined in SMPTE ST2057-1 is set to zero.

In the first example shown in FIG. 9A, the alignment unit 160 is placed between the RTP packet 161a and the RTP packet 166a based on the frame count information acquired from the essence headers 163a and 168a of the RTP packets 161a and 166a. Adjust the time of the essence data. When the time is adjusted based only on the frame count information in the essence header in this way, it is not necessary to output the time stamp information from the transport processing unit 142 to the alignment unit 160, and the information can be referred to across the protocol layers. Is suppressed, so that the configuration of the reception stream processing unit 140 can be simplified.

FIG. 9B is an explanatory diagram for explaining a second example of a method for timing the essence data between two RTP packets. FIG. 9B shows a third RTP packet 161b and a fourth RTP packet 166b. It is assumed that the third RTP packet 161b and the fourth RTP packet 166b are both generated according to ARIB STD-B73. Third RTP packet 161b and the fourth RTP packet 166b is received via a single port _{P M.}

The third RTP packet 161b includes a "timestamp" in the RTP header 162b and a "payload type" and a "frame count" in the essence header 163b. The "timestamp" in the RTP header 162b indicates the value T2. The "payload type" value in the essence header 163b indicates that the corresponding essence payload contains the video essence. The value T2 corresponds to, for example, the capture time of the video frame to which the video essence belongs.

The fourth RTP packet 166b contains a "timestamp" in the RTP header 167b and a "payload type" and a "frame count" in the essence header 168b. The "timestamp" in the RTP header 167b indicates the value T2. The "payload type" value in the essence header 168b indicates that the corresponding essence payload contains audio essences. The value T2 corresponds to, for example, the capture time of the video frame to which the audio essence belongs.

In the second example shown in FIG. 9B, the alignment unit 160 is placed between the RTP packet 161b and the RTP packet 166b based on the RTP time stamps obtained from the RTP headers 162b and 167b of the RTP packets 161b and 166b. Adjust the time of the essence data. When the time is adjusted based on the RTP time stamp in this way, the alignment unit 160 is simply configured by reusing the implementation for the system timing model of SMPTE ST2110-10 which also uses the RTP time stamp. Can be done.

FIG. 9C is an explanatory diagram for explaining a third example of a method for timing the essence data between two RTP packets. FIG. 9C shows a fifth RTP packet 161c and a sixth RTP packet 166c. It is assumed that the fifth RTP packet 161c is generated according to ARIB STD-B73 and the sixth RTP packet 166c is generated according to SMPTE ST2110-30. For example, the 5 RTP packet 161c of received through the port _{P M,} RTP packets 166c of the sixth is received via the port _{P A} for the essence separated streams including audio essence.

The fifth RTP packet 161c includes a "timestamp" in the RTP header 162c and a "payload type" and a "frame count" in the essence header 163c. The "payload type" value of the essence header 163c indicates that the corresponding essence payload contains the video essence, and the "frame count" indicates the value F3. The value F3 corresponds to the capture time of the video frame to which the video essence belongs.

The sixth RTP packet 166c includes a "time stamp" in the RTP header 167c. The "timestamp" of the RTP header 167c indicates the value T3. The value T3 corresponds, for example, to the earliest sampling time of the audio data in the audio essence.

In the third example shown in FIG. 9C, the alignment unit 160 is acquired from the frame count information acquired from the essence header 163c of the fifth RTP packet 161c and the RTP header 167c of the sixth RTP packet 166c. The essence data is timed between the RTP packet 161c and the RTP packet 166c based on the RTP time stamp. For example, in the alignment unit 160, when the sampling time corresponding to the value T3 is included in the frame period of the video frame corresponding to the value F3, the audio data restored from the sixth RTP packet 166c is the fifth RTP packet. It can be determined that the video data restored from 161c should be synchronized to the same video frame. According to such a method, even if an effective time stamp value is not set in the RTP time stamp of the RTP packet of the ARIB STD-B73 stream, the time is appropriately between the ARIB STD-B73 stream and the SMPTE ST2110 stream. You can make adjustments.

FIG. 9D is an explanatory diagram for explaining a fourth example of a method for timing the essence data between two RTP packets. FIG. 9D shows a seventh RTP packet 161d and an eighth RTP packet 166d. It is assumed that the seventh RTP packet 161d is generated according to ARIB STD-B73 and the eighth RTP packet 166d is generated according to SMPTE ST2110-20. For example, RTP packets 161d of the seventh is received via the port _{P M,} RTP packets 166d eighth is received via the port _{P V} for essence separated streams including video essence.

The seventh RTP packet 161d includes a "timestamp" in the RTP header 162d and a "payload type" and a "frame count" in the essence header 163d. The "timestamp" of the RTP header 162d indicates the value T4. A "payload type" value in the essence header 163d indicates that the corresponding essence payload contains audio essences. The value T4 corresponds to, for example, the capture time of the video frame to which the audio essence belongs.

The eighth RTP packet 166d includes a "time stamp" in the RTP header 167d. The "timestamp" of the RTP header 167d indicates the value T4'. The value T4'corresponds to, for example, the capture time of the video frame to which the video essence belongs (in the case of the second field of the interlaced system, the time offset by half the frame period).

In the seventh example shown in FIG. 9D, the alignment unit 160 is acquired from the RTP time stamp acquired from the RTP header 162d of the seventh RTP packet 161d and the RTP header 167d of the eighth RTP packet 166d. Based on the RTP time stamp, the essence data is timed between the RTP packet 161d and the RTP packet 166d. According to such a method, the implementation for the system timing model of SMPTE ST2110-10 utilizing the RTP time stamp is reused for the processing of the ARIB STD-B73 stream, and the alignment unit 160 is simply configured. be able to.

(3) FEC datagram processing unit As described above, error correction processing is not performed in the SMPTE ST2110 series. On the other hand, ARIB STD-B73 supports FEC in an RS (Reed-Solomon) -based method or an XOR-based method. The FEC datagram processing unit 170 is in charge of this error correction processing. That is, the FEC datagram processing unit 170 executes error correction processing on the FEC datagram input from the transport processing unit 142.

For example, when the RS-based method is selected as the error correction method, the FEC datagram processing unit 170 uses the number of datagrams (n, k) set by the control unit 190 as the RS decoding processing unit and RS. Perform decryption. Here, n represents the sum of the number of essence datagrams subject to FEC calculation and the corresponding number of FEC datagrams. k represents the number of essence datagrams. Further, when the XOR-based method is selected as the error correction method, the FEC datagram processing unit 170 uses the FEC block of the size (L, D) set by the control unit 190 as a processing unit and is XOR-based. Perform decryption. Here, L represents the number of essence datagrams in the row direction, and D represents the number of essence datagrams in the column direction.

<2-3. Process flow>
Next, with reference to FIGS. 10 and 11, the main processing flow that can be executed in the first embodiment will be described.

(1) Stream Transmission Processing FIG. 10 is a flowchart showing an example of the flow of the stream transmission processing according to the first embodiment. Here, the stream transmission process will be described as being executed by the broadcast signal processing node 100, but the stream transmission process may be executed by any node having the function of the sender 60 described above.

First, the PTP processing unit 116 synchronizes the device internal clock 110 directly or indirectly with the PTP time source (step S101). The synchronization of the device internal clock 110 with the PTP time source is continuously maintained thereafter.

The transmission stream processing unit 130 generates an essence payload from the essence data input from the data processing unit 180, for example, under the control of the control unit 190 (step S103). Essence data includes either video data, audio data or auxiliary data. The essence payload can be generated, for example, by packing the essence data according to the packing format of video data, audio data or auxiliary data specified by ARIB STD-B73.

Next, the transmission stream processing unit 130 calculates the frame count value (and / or the RTP time stamp) according to the RTP clock 114 having no offset with respect to the media clock 112 locked by the device internal clock 110 (step S105). The frame count value is maintained at the same value while the essence data belonging to the same video frame is processed.

Next, the transmission stream processing unit 130 adds an essence header including a frame count value to the beginning of the essence payload to generate an essence datagram (step S107). The essence header also includes a "payload type" that indicates the type of essence contained in the essence payload.

The transmission stream processing unit 130 then adds a transport header containing an RTP time stamp having a value according to the RTP clock 114 to the essence datagram to generate an RTP packet (step S109). The transmission stream processing unit 130 may further execute an error correction coding process to generate an RTP packet including an FEC datagram.

Next, the transmission unit 122 adds a network (NW) header to the RTP packet generated by the transmission stream processing unit 130 to generate an IP packet (step S111). The port number in the UDP header of the IP packet indicates a common value assigned to the ARIB STD-B73 stream, regardless of the type of essence contained. The destination IP address in the IP header indicates, for example, the multicast address assigned to the stream.

Next, the transmission unit 122 transmits the generated IP packet to the network (step S113). The transmitted IP packet is received by the receiving node that has joined the corresponding multicast group.

The processes of steps S103 to S113 described above can be repeatedly executed while the unprocessed essence data remains (step S115). When all the essence data has been processed, the stream transmission process shown in FIG. 10 ends.

(2) Stream reception processing FIG. 11 is a flowchart showing an example of the flow of the stream reception processing according to the first embodiment.

First, the PTP processing unit 116 of the broadcast signal processing node 100 directly or indirectly synchronizes the device internal clock 110 with the PTP time source (step S151). The synchronization of the device internal clock 110 with the PTP time source is continuously maintained thereafter.

Next, the receiving unit 124 receives the IP packet of the broadcast signal stream transmitted from another node through the same processing as the stream transmission processing described with reference to FIG. 10 (step S153). Since the device internal clock 110 of the broadcast signal processing node 100 is synchronized with the time source of PTP, the broadcast signal processing node 100 is also synchronized with the other node of the source of the IP packet with high accuracy.

The receiving unit 124 then extracts the RTP datagram by removing the network header of the received IP packet (step S153). Then, the receiving unit 124 outputs the extracted RTP datagram to the receiving stream processing unit 140.

Next, the reception stream processing unit 140 extracts the essence payload by removing the transport header and the essence header of the RTP datagram (step S155).

The receive stream processing unit 140 then reverse-packs the essence payload according to the video data, audio data, or auxiliary data packing format specified by ARIB STD-B73, depending on the payload type value in the essence header. Restore the essence data (step S157). Although not shown in FIG. 11, when the FEC datagram is received together with the essence datagram, the reception stream processing unit 140 executes error correction and decoding based on the FEC datagram to obtain the received data. The included bit error may be detected.

Next, the alignment unit 160 of the reception stream processing unit 140 adjusts the time between the essence data derived from different RTP packets based on the RTP time stamp in the RTP header or the frame count information in the RTP payload (step S159). ).

Next, the data processing unit 180 executes processing based on the essence data timed by the alignment unit 160 (step S161). The process executed here may be, for example, synchronous reproduction of a plurality of essences or conversion of essence data into an SDI signal.

The processes of steps S153 to S161 described above can be executed iteratively while packets of the same stream are continuously received (step S163). When the packet reception is stopped, the stream reception process shown in FIG. 11 ends.

<< 3. Second embodiment >>
Next, the second embodiment will be described with reference to FIG. The first embodiment described above is a specific embodiment, while the second embodiment is a more generalized embodiment.

<3-1. Broadcast signal processing node configuration example>
FIG. 12 is a block diagram showing an example of the configuration of the broadcast signal processing node 200 according to the second embodiment. The broadcast signal processing node 200 is a node that receives a broadcast signal stream from one or more other nodes. The stream received by the broadcast signal processing node 200 includes, but is not limited to, an essence mixed stream such as an ARIB STD-B73 stream. Referring to FIG. 12, the broadcast signal processing node 200 includes a communication unit 210 and an alignment unit 220.

The communication unit 210 is an RTP packet in which the RTP header is time-stamped according to the RTP clock having no offset with respect to the media clock locked by the device internal clock directly or indirectly synchronized with the PTP time source. Then, the RTP packet (first RTP packet) including the essence data corresponding to any one of the video data, the audio data, and the auxiliary data in the RTP payload is received. The communication unit 210 also receives another RTP packet (second RTP packet). The first RTP packet and the second RTP packet may be packets included in the same broadcast signal stream, or may be packets included in different broadcast signal streams.

The alignment unit 220 is based on the time stamp acquired from the RTP header of the received RTP packet or the frame count information acquired from the header in the RTP payload of the received RTP packet. The essence data is timed between the RTP packet and the other RTP packet described above.

The broadcast signal processing for time adjustment of the essence data may include the above-mentioned operation step of the broadcast signal processing node 200. In addition, a computer program that causes a processor to execute these operation steps may be provided. In addition, a non-temporary computer-readable storage medium that stores a computer program that causes a processor to execute these operation steps may be provided. In addition, any function or process described in the first embodiment may be applied to the present embodiment.

<3-2. Modification example>
FIG. 13 is a block diagram showing an example of the configuration of the broadcast signal processing node 200 according to the first modification of the second embodiment. Referring to FIG. 13, the broadcast signal processing node 200 includes a reproduction unit 230 in addition to the communication unit 210 and the alignment unit 220 described with reference to FIG.

The reproduction unit 230 synchronously reproduces the essence based on the essence data of the RTP packet (first RTP packet) and the other RTP packet (second RTP packet) timed by the alignment unit 220. To do. For example, images received from a plurality of cameras may be reproduced at the same time, images and sounds may be reproduced synchronously, or auxiliary data may be reproduced together with images and / or sounds.

FIG. 14 is a block diagram showing an example of the configuration of the broadcast signal processing node 200 according to the second modification of the second embodiment. Referring to FIG. 14, the broadcast signal processing node 200 includes a first communication unit 215, an alignment unit 220, a conversion unit 240, and a second communication unit 250.

The first communication unit 215 adds a time stamp to the RTP header according to the RTP clock having no offset with respect to the media clock locked by the device internal clock directly or indirectly synchronized with the PTP time source. The RTP packet (first RTP packet) including the essence data corresponding to any one of the video data, the audio data, and the auxiliary data in the RTP payload is received. The first communication unit 215 also receives another RTP packet (second RTP packet). The first RTP packet and the second RTP packet may be packets included in the same broadcast signal stream, or may be packets included in different broadcast signal streams.

The conversion unit 240 is derived from the RTP packets based on the time adjustment of the essence data between the RTP packet (first RTP packet) and the other RTP packet (second RTP packet) by the alignment unit 220. The essence data to be processed is converted into an SDI signal. The signal format of the SDI signal generated by the converter 240 may be any derivative of the SDI, for example SD-SDI, HD-SDI, 3G-SDI, 6G-SDI or 12G-SDI.

The second communication unit 250 transmits the SDI signal generated by the conversion unit 240 based on the time adjustment described above to another node belonging to the SDI domain.

<< 4. Summary of the first embodiment and the second embodiment >>
So far, the first embodiment and the second embodiment of the present disclosure have been described in detail. In the above-described embodiment, the time adjustment of the essence data between the RTP packet containing the essence data corresponding to any one of the video data, the audio data, and the auxiliary data in the RTP payload and the other RTP packet is the RTP header. It is performed based on the RTP time stamp in the RTP time stamp or the frame count information obtained from the header in the RTP payload. The RTP timestamp is given according to the RTP clock, which has no offset to the media clock locked to the device internal clock that is directly or indirectly synchronized with the PTP time source. According to such a configuration, when using a protocol for transmitting essence data such as video data, audio data or auxiliary data in a single stream on the IP network of a broadcasting station, it is possible to appropriately time the essence data. It is possible.

In one example, the RTP packet is a packet generated according to the protocol for mixed essence streams. The essence mixed stream may be, for example, an ARIB STD-B73 stream. The ARIB STD-B73 stream does not contain data corresponding to the blanking period. According to these examples, the essence data can be easily timed without complicating the process of reconstructing the original content on the receiving side and avoiding the possibility of different delays on the network for each essence type. can do.

In one example, the clock frequency of the media clock is equal to 27.0 MHz. According to such a configuration, the clock frequency of the media clock is made an integral multiple of the video frame frequency to accurately keep the frame period constant, while forming a single essence mixed stream that can contain video data, audio data, and auxiliary data. Information for time adjustment can be added in a common way based on the clock frequency of the media clock.

<< 5. Third Embodiment >>
As already mentioned above, the format of SDP objects commonly used for SMPTE ST2110 streams is not always suitable for the characteristics of ARIB STD-B73 streams, neither in the format structure nor in the content of the information described. .. In order to properly set up the transmission of the ARIB STD-B73 stream, it is necessary to define the format of the SDP object suitable for the characteristics of the stream.

<5-1. Example of existing SDP object>
SDP is a protocol that defines the format for writing a set of parameters used for streaming (or any other session) in text format, typically with the sender of the stream prior to the start of streaming. By sending and receiving an SDP object (for example, a data file described in SDP format) with the receiving side, negotiations are held on what parameter values should actually be used, and an agreement is reached. Alternatively, if the control node is centrally involved in setting up the stream, the SDP object may be provided to that control node.

FIG. 15 is an explanatory diagram for explaining a typical format structure of an SDP object for an essence-separated stream. As shown in FIG. 15, an SDP object is a session-level section for describing session-level attributes (specific to the session rather than the individual media belonging to the session) and the respective attributes of one or more media. Includes one or more media level sections for describing. The SDP object of FIG. 15 contains respective media level sections for video essence, audio essence, and auxiliary data essence. Optionally, if a redundant RTP stream method is applied to the video essence to improve availability, the media level section for the secondary video essence should be included in the SDP object in addition to the media level section for the primary video essence. Can be. The redundant RTP stream method is not limited to such an example, and may be applied to any one or more of the video essence, the audio essence, and the auxiliary data essence. Each media level section contains a set of attribute fields that describe the attributes of the corresponding essence type stream. That is, the media level section for the video essence is the video-related attribute field group, the media level section for the audio essence is the audio-related attribute field group, and the media level section for the auxiliary data essence is the auxiliary data-related attribute field group. May include.

FIG. 16 shows an example of an SDP object describing the attributes of the SMPTE ST2110 stream, which has the format structure described with reference to FIG.

Referring to FIG. 16, the SDP object 301 includes a session level section 302 and four media level sections 303, 304, 305 and 306. Session level section 302 is for describing session-specific information such as protocol version fields (“v =…”), source fields (“o =…”), and session name fields (“s =…”). It has a field group.

The beginning of an individual media level section is identified by a media description field (“m =…”). Media level sections 303 and 304 are sections for streams of video essence. In the example of FIG. 16, the media level section 303 describes the attributes of the primary video essence stream, and the media level section 304 describes the attributes of the secondary video essence stream. Media level section 305 describes the attributes of the audio essence stream. Media level section 306 describes the attributes of the stream of auxiliary data essences.

Media level for video In the media description field (“m =…”) at the beginning of section 303, the media type (“video”), transmission port number (“50000”), transport protocol (“RTP / AVP”)) , And the format format number (“112”) are described. In addition to this media description field, the media level section 303 includes a group of video-related attribute fields 307. The video-related attribute field group 307 includes a source filter attribute field (“a = source-filter:…”), an RTP map attribute field (“a = rtpmap:…”), and a format-specific parameter attribute field (“a = fmtp:…”). ”), Reference clock attribute field (“a = ts-refclk:… ”), media clock attribute field (“a = mediaclk:… ”), and map ID attribute field (“a = mid:… ”). Of these, the RTP map attribute field (“a = rtpmap:…”) is the payload type number (“112”) and subtype name (“raw”) that have the same value as the format format number of the corresponding media description field. And the media clock frequency (“90000”). The format-specific parameter attribute field (“a = fmtp:…”) lists the format format number (“112”) followed by a parameter name / parameter value pair for one or more format-specific parameters. The map ID attribute field (“a = mid:…”) is used to distinguish between a primary stream and a secondary stream when redundant RTP streams are used. The content of the media level section 304 may be the same as that of the media level section 303 except for the transmission port number and the map ID attribute field of the media description field, and is therefore omitted in FIG.

Media Level for Audio In the media description field (“m =…”) at the beginning of section 305, the media type (“audio”), transmit port number (“51200”), transport protocol (“RTP / AVP”). , And the format format number (“97”) are described. In addition to this media description field, media level section 305 includes audio-related attribute fields 308. The voice-related attribute field group 308 includes an RTP map attribute field (“a = rtpmap:…”), a packet time attribute field (“a = ptime:…”), and a reference clock attribute field (“a = ts-refclk:…”). ), Media clock attribute field (“a = mediaclk:…”), format-specific parameter attribute field (“a = fmtp:…”), and map ID attribute field (“a = mid:…”). Of these, the RTP map attribute field (“a = rtpmap:…”) is the payload type number (“97”) and subtype name (“L24”) that have the same value as the format format number of the corresponding media description field. , Media clock frequency (“48000”) and coding parameters (“6”). The subtype name "L24" indicates that the voice essence is encoded by 24-bit linear encoding. The coding parameter “6” indicates that the number of audio channels is 6. The format-specific parameter attribute field (“a = fmtp:…”) lists the format format number (“97”) followed by a parameter name / parameter value pair for one or more format-specific parameters.

Media level for auxiliary data In the media description field (“m =…”) at the beginning of section 306, the media type (“video”), transmit port number (“51300”), transport protocol (“RTP / AVP”) ), And the format format number (“98”) are described. In addition to this media description field, the media level section 306 includes a set of auxiliary data related attribute fields 309. The auxiliary data-related attribute field group 309 includes an RTP map attribute field (“a = rtpmap:…”), a reference clock attribute field (“a = ts-refclk:…”), and a media clock attribute field (“a = mediaclk:…”). ”), And the map ID attribute field (“a = mid:… ”). Of these, the RTP map attribute field (“a = rtpmap:…”) is the payload type number (“98”) and subtype name (“smpte291”) that have the same value as the format format number of the corresponding media description field. And the media clock frequency (“90000”).

As can be seen from FIG. 16, an SDP object for an SMPTE ST2110 stream contains a respective media level section of multiple essence types, each of which has a different set of fields depending on the corresponding essence type. Have. Such a format structure is reusable for essence-separated streams similar to SMPTE ST2110 streams, but is not suitable for describing the attributes of essence-mixed streams such as ARIB STD-B73 streams. This is because a mixed essence stream contains data of multiple essence types in a single stream. Furthermore, the information items required to set up the ARIB STD-B73 stream, which supports compression of the video essence and is also capable of error correction coding / decoding, are insufficient for the SDP object format illustrated in FIG. ..

<5-2. New format for SDP objects>
FIG. 17 is an explanatory diagram for explaining the format structure of the SDP object defined for the essence mixed stream in the present embodiment.

As shown in FIG. 17, in the new format, SDP objects include a session level section that describes session level attributes and a media level section that is common to multiple essence types. Then, one common media level section contains a set of attribute fields for describing attributes related to video essence, audio essence, and auxiliary data essence. In particular, in the present embodiment, parameters that are not assigned independent attribute fields in the SDP standard are described in the format-specific parameter attribute field. In this way, by adapting the structure of the SDP object to the characteristics of the essence mixed stream (or ARIB STD-B73 stream), the information unique to the stream can be described in the SDP object without ambiguity.

Optionally, if a redundant RTP stream scheme is applied to improve availability, the SDP object may include a media level section common to the secondary essence in addition to the media level section common to the primary essence.

FIG. 18 shows an example of an SDP object describing the attributes of the ARIB STD-B73 stream, which has the format structure described with reference to FIG.

Referring to FIG. 18, the SDP object 311 includes a session level section 312 and two media level sections 313 and 318. Session level section 312 is for describing session-specific information such as protocol version fields (“v =…”), source fields (“o =…”), and session name fields (“s =…”). It has a field group.

The beginnings of media level sections 313 and 318 are identified by their respective media description fields (“m =…”). Both media level sections 313 and 318 are common sections for multiple essence types. In the example of FIG. 18, the attributes of the primary mixed essence stream are described in the media level section 313, and the attributes of the secondary mixed essence stream are described in the media level section 318.

The media description field (“m =…”) at the beginning of media level section 313 contains the media type (“video”), transmit port number (“50000”), transport protocol (“RTP / AVP”), and format. The model number (“110”) is described. Although the media level section 313 is a section common to a plurality of essence types as described above, in the technique according to the present disclosure, since the timing of each essence is associated with the video frame, the character string of the media type is described here. “Video” can be selected as. The transmission port number may be, for example, a UDP port number arbitrarily selected from the range of private port numbers. The format format number may be another value (eg, "111"). In the present embodiment, the format format number serves as a format identification value commonly assigned to a plurality of essence types. In addition to this media description field, the media level section 313 includes a group of attribute fields 314. In particular, in the example of FIG. 18, the attribute field group 314 includes an RTP map attribute field (“a = rtpmap:…”) 315, a format-specific parameter attribute field (“a = fmtp:…”) 316, and a packet time attribute field (“a = fmtp:…”). “A = ptime:…”) 317 is included.

The RTP map attribute field 315 is associated with the media description field at the beginning of media level section 313 by a payload type number (“110”) that has the same value as the format format number. For example, the protocol name "ARIB_STD-B73" is described in the subtype name of the RTP map attribute field 315, and the broadcast signal stream transmitted by the sender providing the SDP object 311 is the ARIB STD-B73 stream from this name. Is identified. The media clock frequency indicated by the RTP map attribute field 315 is here 27 MHz.

The format-specific parameter attribute field 316 is associated with the media description field at the beginning of the media level section 313 by the format format number (“110”). The format-specific parameter attribute field 316 contains at least the first attribute information related to the essence data of the first essence type and the second attribute information related to the essence data of the second essence type. In the example of FIG. 18, the format-specific parameter attribute field 316 contains information classified as follows:
-Video-related attributes-Attribute information related to video essence essence data-Voice-related attributes-Attribute information related to voice essence essence data-Auxiliary data-related attributes-Attribute information related to auxiliary data essence essence data-FEC-related Attribute-Attribute information related to error correction method-Traffic shaping related attribute-Attribute information related to traffic shaping

The following Tables 1 to 5 list the parameters of the video-related attribute, the audio-related attribute, the auxiliary data-related attribute, the FEC-related attribute, and the traffic shaping-related attribute that can be described in the format-specific parameter attribute field 316 in the present embodiment. Shown.

In this embodiment, compression-related information indicating whether the video essence data is compressed is newly defined. Video-related attributes, including this compression-related information, may be described in format-specific parameter attribute field 316 of media level section 313 of SDP object 311. Specifically, for example, as shown in Table 1, the compression-related information includes a compression parameter “compression” indicating whether or not the video essence data is compressed. Further, when the compression parameter indicates that the video essence data is compressed, the compression-related information includes a codec parameter “codec” indicating a codec (compression method) used when compressing the video essence data. ..

According to the existing SDP format, the audio channel number information related to the audio essence data is stored in the RTP map attribute field (“a = rtpmap:…”) in the media level section for audio, as illustrated in FIG. Will be described. However, as in the present embodiment, when only the media level section common to a plurality of essence types is provided and "video" is selected as the character string of the media type, the audio channel number information is described in the RTP map attribute field. Violates the SDP standard. Therefore, in the present embodiment, as shown in Table 2, audio channel number information is defined as a format-specific audio-related attribute. The audio-related attribute including the audio channel number information may be described in the format-specific parameter attribute field 316 of the media level section 313 of the SDP object 311 together with the video-related attribute described above. Specifically, for example, the voice channel number information includes the voice channel number parameter “channel-number”. In SMPTE ST2110-30, the number of audio channels can be any integer in the range from 1 to a different upper limit depending on the level, but in ARIB STD-B73, the number of audio channels is any of 4, 8, 12 or 16. Is constrained.

In this embodiment, auxiliary data related attributes, along with video related attributes (and audio related attributes), can be described in the format specific parameter attribute field 316 of the media level section 313 of the SDP object 311. Specifically, for example, as shown in Table 3, the auxiliary data-related attributes include a data ID and a secondary data ID “DID_SDID” and a video payload ID code “VPID_Code”.

In this embodiment, error correction information indicating an error correction method applied to the essence data is newly defined. This error correction information, along with the other attributes described above, may be described in the format specific parameter attribute field 316 of the media level section 313 of the SDP object 311. Specifically, for example, as shown in Table 4, the error correction information includes a type parameter “FECtype” indicating an error correction method applied to the essence data, and a set value of the error correction method indicated by the type parameter. Includes setting parameters that indicate. If the type parameter indicates XOR coding (“XOR”), the configuration parameter includes a size parameter “XORsize” indicating the error correction block size. On the other hand, when the type parameter indicates Reed-Solomon coding (“RS”), the setting parameter includes a datagram number parameter “RSnum” indicating the number of datagrams corresponding to the processing unit of Reed-Solomon coding.

In this embodiment, the traffic shaping related attributes can be described in the format specific parameter attribute field 316 of the media level section 313 of the SDP object 311 along with the other attributes described above. Specifically, for example, as shown in Table 5, the traffic shaping-related attribute includes a buffer type parameter “TP” indicating the type of the sender's buffer.

In this embodiment, the packet time attribute field 317 is included in the same media level section 313 as the format specific parameter attribute field 316. This is in contrast to the packet time attribute field (“a = ptime:…”) contained in the audio media level section 305, which is different from the audio media level section 303 in the example of FIG. Is. The packet time attribute field 317 indicates the time length of the media in the packet in milliseconds. The time length indicated by this field affects the buffer size of the device. In this embodiment, the time length indicated by the packet time attribute field 317 can be applied only to the voice essence.

The format-specific parameters listed in Tables 1 to 5 are only examples. The media level section common to multiple essence types may contain other additional parameters, or one or more of the parameters shown in the table may be omitted.

The content of the media level section 318 may be the same as that of the media level section 313, except for some parts such as the map ID attribute field. If the redundant RTP stream scheme is not applied, media level section 318 is not included in SDP object 311.

By using the format structure of the SDP object described in this section, it is possible to appropriately describe the attributes of the essence mixed type stream such as the ARIB STD-B73 stream according to the structure of the stream. Furthermore, it is possible to set up an ARIB STD-B73 stream that supports compression of video essence and can also perform error correction coding / decoding by exchanging information about the attributes of the stream without lack through the provision of SDP objects. It becomes.

<5-3. Broadcasting station system configuration example>
FIG. 19 is a block diagram showing an example of a schematic configuration of the broadcasting station system 3 according to the third embodiment. Referring to FIG. 19, the broadcasting station system 3 includes one or more transmitting nodes 300a to 300n, a control node 400, and one or more receiving nodes 450a to 450n.

Each of the transmission nodes 300a to 300n (hereinafter referred to as a transmission node 300) is a broadcast signal processing node capable of transmitting a broadcast signal stream in the broadcasting station system 3. Each transmitting node 300 has at least one sender 60. The transmission node 300 provides the control node 400 with an SDP object that describes the attributes of the stream that it can transmit. The SDP object provided by the transmitting node 300 can be described according to the new format for essence mixed streams described with reference to FIGS. 17 and 18.

The control node 400 is a node that controls transmission of a broadcast signal stream from a transmitting node to a receiving node in the IP network of a broadcasting station. The broadcast signal stream transmitted in the broadcasting station system 3 includes an essence mixed stream that transmits different types of essence data with a single port number. The control node 400 sets up transmission of a stream between designated nodes in response to receiving a request from an external device such as the APS 40 or the control terminal 50 illustrated in FIG. 1, and starts transmission to the transmission node 300. To instruct. The setup for transmission of the mixed essence stream can be performed according to the description of the SDP object provided by the source transmission node 300.

Each of the receiving nodes 450a to 450n (hereinafter referred to as receiving node 450) is a broadcasting signal processing node capable of receiving a broadcasting signal stream in the broadcasting station system 3. Each receiving node 450 has at least one receiver 65. Under the control of the control node 400, the reception node 450 configures the reception process for receiving the broadcast signal stream according to the description of the SDP object, and receives the broadcast signal stream from the transmission node 300. When the broadcast signal stream to be received is a mixed essence stream, the receiving node 450 receives different types of essence data with a single port number (that is, within a single stream). The configuration of the receiving node 450 may be the same as the configuration of the broadcast signal processing node 100 described in the first embodiment or the broadcast signal processing node 200 described in the second embodiment.

<5-4. Outgoing node configuration example>
FIG. 20 is a block diagram showing an example of the configuration of the transmission node 300 according to the present embodiment. Referring to FIG. 20, the transmission node 300 includes a device internal clock 110, a media clock 112, an RTP clock 114, a PTP processing unit 116, a communication unit 320, a transmission stream processing unit 130, a reception stream processing unit 140, and a data processing unit 180. It includes a control unit 390 and a storage unit 395.

(1) Communication unit The communication unit 320 is an interface that mediates communication between the transmission node 300 and other nodes. The communication unit 320 may include a connection terminal and a connection circuit for wired communication, or may include an antenna, an RF circuit, and a baseband circuit for wireless communication. In the present embodiment, the communication unit 320 includes a transmission unit 322 and a reception unit 324.

The transmission unit 322 has a role as a sender 60, and transmits an essence mixed stream to the IP network of the broadcasting station system 3. The broadcast signal stream may be, for example, an ARIB STD-B73 stream. Specifically, a series of RTP packets for the broadcast signal stream generated by the transmission stream processing unit 130 is input to the transmission unit 322. Each RTP packet contains time information (RPP time stamp and / or frame count information) similar to that of the first embodiment and the second embodiment. The transmission unit 322 adds a network header to each input RTP packet, and transmits each packet to another node.

The transmitting unit 322 and the receiving unit 324 are also involved in the control communication related to the transmission of the stream. Specifically, for example, the receiving unit 324 receives various control messages related to the transmission of the stream from the control node 400 (or other node such as the receiving node 450). The transmission unit 322 transmits a response message to the control message to the control node 400 (or another node such as the reception node 450).

In the present embodiment, the receiving unit 324 may or may not have a role as the receiver 65.

(2) Control Unit The control unit 390 includes one or more processors such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or a microcontroller. The control unit 390 controls the overall operation of the transmission node 300 by executing the computer program stored by the storage unit 395.

For example, when the transmission node 300 is connected to the IP network of the broadcasting station system 3, the control unit 390 discovers the control node 400 by issuing an mDNS (multicast Domain Name System) query and receiving the response. Further, the control unit 390 receives, for example, a control message requesting the provision of the SDP object from the control node 400 via the reception unit 324. Upon receiving the control message, the control unit 390 acquires an SDP object from the storage unit 395 that describes the attributes of the broadcast signal stream according to the new format described above for the essence mixed stream. Then, the control unit 390 transmits the acquired SDP object to the control node 400 via the transmission unit 322.

After the stream transmission is set up based on the SDP object provided by the transmitting node 300, the control unit 390 receives a control message from the control node 400 instructing the start of transmission of the stream via the receiving unit 324. .. In response to the reception of the control message, the control unit 390 starts transmitting the broadcast signal stream from the transmission unit 322.

For example, the transmit node 300 may support an NMOS, which is a set of control interface standards for managing and controlling the transmission of streams. In this case, the above-mentioned exchange of control messages may be performed, for example, via the HTTP (Hypertext Transfer Protocol) -based control API defined in the NMOS IS-04 and NMOS IS-05.

(3) Storage unit The storage unit 395 includes temporary and non-temporary computer-readable memory. Temporary memory may include, for example, RAM (Random Access Memory). The non-temporary memory may include, for example, one or more of a ROM (Read Only Memory), an HDD (Hard Disk Drive), or an SSD (Solid State Drive). The storage unit 395 stores a computer program for realizing the functionality of the transmission node 300. Further, in the present embodiment, the storage unit 395 stores an SDP object that describes the attributes of the broadcast signal stream that can be transmitted by the transmission node 300.

In one aspect, the SDP object contains the first attribute information and the second essence type related to the essence data of the first essence type in the attribute field associated with the media description field common to the plurality of essence types. Contains a second attribute information related to the essence data. As an example, the first essence type may be a video essence and the second essence type may be an audio essence. In this case, the SDP object contains the video-related attributes as illustrated in Table 1 as the first attribute information and the audio-related attributes as illustrated in Table 2 in the attribute field common to a plurality of essence types. It can be included as the attribute information of 2. As another example, the first essence type may be a video essence and the second essence type may be an auxiliary data essence. In this case, the SDP object sets the video-related attributes as illustrated in Table 1 as the first attribute information and the auxiliary data-related attributes as illustrated in Table 3 in the attribute field common to a plurality of essence types. It can be included as the second attribute information. Not limited to these examples, the SDP object provided by the transmitting node 300 may include any combination of the information exemplified in Tables 1 to 5.

From another point of view, the SDP object is compression-related information indicating whether the video essence data is compressed, information on the number of audio channels related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. , Are included in the attribute field that describes the format-specific parameters of the broadcast signal stream. As described with reference to Table 1, the above compression-related information includes a compression parameter indicating whether the video essence data is compressed, and a video essence data when the compression parameter indicates that the video essence data is compressed. It may include a codec parameter indicating the codec used when compressing. Further, as described with reference to Table 4, the above error correction information includes a type parameter indicating an error correction method applied to the essence data and a setting parameter indicating an error correction method setting value indicated by the type parameter. May include. The setting parameter may be, for example, a size parameter indicating an error correction block size for XOR coding, or a datagram number parameter indicating the number of datagrams corresponding to a processing unit for Reed-Solomon coding.

(4) Flow of Transmission Control Processing-First Example FIG. 21 is a flowchart showing a first example of the flow of transmission control processing that can be executed by the transmission node 300.

First, the control unit 390 discovers the control node 400 according to the connection of the transmission node 300 to the IP network (step S301).

Next, the control unit 390 acquires an SDP object describing the attributes of the broadcast signal stream that can be transmitted by the transmission node 300 from the storage unit 395, and provides the acquired SDP object to the control node 400 (step S303). The SDP object provided here contains attribute information related to the essence data of the first and second essence types in the attribute field associated with the media description field common to the plurality of essence types.

After that, the transmission node 300 waits for an instruction to start transmitting the stream (step S305). Then, when a control message instructing the start of stream transmission is received from the control node 400 (or another node), the transmission unit 322 sets the attributes indicated by the SDP object under the control of the control unit 390. The transmission of the broadcast signal stream to be carried is started (step S307).

(5) Flow of Transmission Control Processing-Second Example FIG. 22 is a flowchart showing a second example of the flow of transmission control processing that can be executed by the transmission node 300.

First, the control unit 390 discovers the control node 400 according to the connection of the transmission node 300 to the IP network (step S301).

Next, the control unit 390 acquires an SDP object describing the attributes of the broadcast signal stream that can be transmitted by the transmission node 300 from the storage unit 395, and provides the acquired SDP object to the control node 400 (step S304). The SDP object provided here contains one or more of compression-related information, audio channel number information, and error correction information in an attribute field that describes format-specific parameters of the broadcast signal stream.

After that, the transmission node 300 waits for an instruction to start transmitting the stream (step S305). Then, when a control message instructing the start of stream transmission is received from the control node 400 (or another node), the transmission unit 322 sets the attributes indicated by the SDP object under the control of the control unit 390. The transmission of the broadcast signal stream to be carried is started (step S307).

<5-5. Control node configuration example>
FIG. 23 is a block diagram showing an example of the configuration of the control node 400 according to the present embodiment. Referring to FIG. 23, the control node 400 includes a communication unit 410, a control unit 420, and a storage unit 430.

(1) Communication unit The communication unit 410 is an interface that mediates communication between the control node 400 and other nodes. The communication unit 410 may include a connection terminal and a connection circuit for wired communication, or may include an antenna, an RF circuit and a baseband circuit for wireless communication. In the present embodiment, the communication unit 410 includes a transmission unit 412 and a reception unit 414.

The transmitting unit 412 and the receiving unit 414 are involved in the control communication related to the transmission of the stream on the IP network in the broadcasting station system 3. Specifically, for example, the transmission unit 412 may transmit a control message for setting up the transmission of the stream and starting or ending the transmission to the transmission node 300. Similarly, the transmitting unit 412 may transmit a control message to the receiving node 450 for setting up the transmission of the stream and starting or ending the reception. The receiving unit 414 can receive a response message to the control message from the transmitting node 300 and the receiving node 450.

(2) Control unit The control unit 420 includes one or more processors such as a CPU, an MPU, or a microcontroller. The control unit 420 controls the overall operation of the control node 400 by executing the computer program stored in the storage unit 430. In the present embodiment, the control unit 420 includes an information management unit 422 and a stream control unit 424.

The information management unit 422 registers and manages information about the broadcast signal processing node in the broadcasting station system 3 in the database. For example, when the information management unit 422 discovers the transmission node 300 connected to the IP network, it transmits a control message requesting the provision of the SDP object to the discovered transmission node 300 via the transmission unit 412. Then, the information management unit 422 receives the SDP object from the transmission node 300 via the reception unit 414. The SDP object received from the transmitting node 300 describes the attributes of the broadcast signal stream that can be transmitted by the transmitting node 300. The information management unit 422 registers the information described in the received SDP object in the database of the storage unit 430. The information management unit 422 can also acquire an SDP object from the receiving node 450 and register information such as stream attributes that can be received by the receiving node 450 in the database of the storage unit 430.

The stream control unit 424 controls the transmission of the stream from the transmitting node 300 to the receiving node 450 in the broadcasting station system 3. For example, the stream control unit 424 instructs the receiving node 450 to set up the reception of the broadcast signal stream from the designated transmitting node 300 when the request for stream transmission is received from the APS 40 or the control terminal 50. To do. The stream control unit 424 may determine how the reception process should be set up, for example, by referring to the attributes of the stream registered in the database of the storage unit 430. For example, one or more of the following can be determined depending on the attributes of the stream:
-Should the received video essence data be decompressed? -Codec to be used when performing decompression-How many audio channels are included in the audio essence data-Which method should be used as the error correction method? (XOR or RS)
-FEC block size when performing error correction by XOR decoding-Number of datagrams as a processing unit when performing error correction by RS decoding

The receiving node 450 sets up the reception of the broadcast signal stream by configuring the reception process and joining the corresponding multicast group according to the above instructions received from the stream control unit 424. Then, the stream control unit 424 instructs the transmission node 300 to start transmitting the broadcast signal stream. Accordingly, the transmission node 300 starts transmitting the broadcast signal stream.

(3) Storage unit The storage unit 430 includes temporary and non-temporary computer-readable memory. Temporary memory may include, for example, RAM. The non-temporary memory may include, for example, one or more of ROM, HDD or SSD. The storage unit 430 stores a computer program for realizing the functionality of the control node 400. Further, in the present embodiment, the storage unit 430 stores the information described in the SDP objects collected from the nodes in the broadcasting station system 3 by the information management unit 422 in the database.

(4) Flow of Transmission Control Processing-First Example FIG. 24 is a flowchart showing a first example of the flow of transmission control processing that can be executed by the control node 400.

First, the information management unit 422 discovers the transmission node 300 connected to the IP network (step S401).

Next, the information management unit 422 acquires an SDP object that describes the attributes of the broadcast signal stream that can be transmitted by the discovered transmission node 300 by receiving it from the transmission node 300 (step S403). The SDP object acquired here contains the attribute information related to the essence data of the first and second essence types in the attribute field associated with the media description field common to the plurality of essence types.

The stream control unit 424 listens for a request for setting up stream transmission (step S405). A request to set up the transmission of a stream may be received from an external device such as the APS 40 or the control terminal 50.

When the request is received, the stream control unit 424 instructs the designated receiving node 450 to configure the reception process according to the attribute indicated by the SDP object and join the corresponding multicast group (step S407). ). Then, the stream control unit 424 instructs the designated transmission node 300 to start transmitting the broadcast signal stream (step S409).

(5) Flow of Transmission Control Processing-Second Example FIG. 25 is a flowchart showing a second example of the flow of transmission control processing that can be executed by the control node 400.

First, the information management unit 422 discovers the transmission node 300 connected to the IP network (step S401).

Next, the information management unit 422 acquires an SDP object that describes the attributes of the broadcast signal stream that can be transmitted by the discovered transmission node 300 by receiving it from the transmission node 300 (step S404). The SDP object acquired here contains one or more of compression-related information, audio channel number information, and error correction information in an attribute field that describes a format-specific parameter of the broadcast signal stream.

The stream control unit 424 listens for a request for setting up stream transmission (step S405). A request to set up the transmission of a stream may be received from an external device such as the APS 40 or the control terminal 50.

When the request is received, the stream control unit 424 instructs the designated receiving node 450 to configure the reception process according to the attribute indicated by the SDP object and join the corresponding multicast group (step S407). ). Then, the stream control unit 424 instructs the designated transmission node 300 to start transmitting the broadcast signal stream (step S409).

<< 6. Fourth Embodiment >>
Next, a fourth embodiment will be described with reference to FIGS. 26 and 27. The third embodiment described above is a specific embodiment, while the fourth embodiment is a more generalized embodiment.

<6-1. Outgoing node configuration example>
FIG. 26 is a block diagram showing an example of the configuration of the transmission node 500 according to the fourth embodiment. Referring to FIG. 26, the transmission node 500 includes a transmission unit 510 and a control unit 520.

The transmission unit 510 transmits a broadcast signal stream that transmits different types of essence data with a single port number to the IP network of the broadcasting station.

The control unit 520 provides another node with an SDP object that describes the attributes of the broadcast signal stream.

In one aspect, the SDP object contains the first attribute information and the second essence type related to the essence data of the first essence type in the attribute field associated with the media description field common to the plurality of essence types. Contains a second attribute information related to the essence data.

From another viewpoint, the SDP object is compression-related information indicating whether the video essence data is compressed, information on the number of audio channels related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. , One or more of the above are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.

The transmission control process performed for setting up the transmission of the stream may include the above-mentioned operation step of the transmission node 500. In addition, a computer program that causes a processor to execute these operation steps may be provided. In addition, a non-temporary computer-readable storage medium that stores a computer program that causes a processor to execute these operation steps may be provided. In addition, any function or process of the transmitting node 300 described in the third embodiment may be applied to the present embodiment.

<6-2. Control node configuration example>
FIG. 27 is a block diagram showing an example of the configuration of the control node 600 according to the fourth embodiment. Referring to FIG. 27, the control node 600 includes a control unit 610.

The control node 600 is a node that controls transmission of a broadcast signal stream that transmits different types of essence data with a single port number from a transmitting node to a receiving node in the IP network of a broadcasting station. The control unit 610 acquires an SDP object that describes the attributes of the broadcast signal stream from the transmission node. Then, the control unit 610 sets up the transmission of the broadcast signal stream according to the acquired SDP object.

In one aspect, the SDP object contains the first attribute information and the second essence type related to the essence data of the first essence type in the attribute field associated with the media description field common to the plurality of essence types. Contains a second attribute information related to the essence data.

From another viewpoint, the SDP object is compression-related information indicating whether the video essence data is compressed, information on the number of audio channels related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. , One or more of the above are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.

The transmission control process performed to set up the transmission of the stream may include the operation step of the control node 600. In addition, a computer program that causes a processor to execute these operation steps may be provided. In addition, a non-temporary computer-readable storage medium that stores a computer program that causes a processor to execute these operation steps may be provided. In addition, any function or process of the control node 400 described in the third embodiment may be applied to the present embodiment.

<< 7. Summary of the third embodiment and the fourth embodiment >>
So far, the third embodiment and the fourth embodiment of the present disclosure have been described in detail. In these embodiments, an SDP object that describes the attributes of a so-called mixed essence stream that carries different types of essence data over a single port number is contained within an attribute field associated with a media description field that is common to multiple essence types. , The first attribute information related to the essence data of the first essence type and the second attribute information related to the essence data of the second essence type are included. Therefore, the attributes of an essence mixed stream such as the ARIB STD-B73 stream can be appropriately described in the SDP object according to the structure of the stream. As a result, it is possible to set up the transmission of the essence mixed stream by a simple procedure by exchanging the SDP objects by utilizing the SDP-based management API.

For example, as described with reference to FIG. 15, the existing SDP object format commonly used for SMPTE ST2110 streams describes audio-related attributes in addition to the media-level section where video-related attributes are described. It has a media level section and a media level section where auxiliary data related attributes are described. In contrast, as in the third and fourth embodiments, one by describing the attributes associated with the essence data of those essence types in a media level section common to two or more essence types. Consistency of SDP interpretation of one media level section for media (stream) can be maintained.

Additional or alternative, the SDP object that describes the attributes of the mixed essence stream is compression-related information that indicates whether the video essence data is compressed, audio channel number information related to the audio essence data, and essence data. Contains one or more of the error correction information indicating the error correction method applied to in the attribute field that describes the format-specific parameters. Therefore, the attributes of a broadcast signal stream having its own specifications, such as the ARIB STD-B73 stream, can be described in the SDP object without any shortage. As a result, the transmission of the ARIB STD-B73 stream can be set up by a simple procedure by exchanging SDP objects by utilizing the SDP-based management API.

For example, as described with reference to FIG. 16, the existing SDP object formats commonly used for SMPTE ST2110 streams include compression-related information, audio channel count information, and error correction information within format-specific parameter attribute fields. Does not have any of. In contrast, as in the third and fourth embodiments, ARIB STD-B73 by including compression-related information, audio channel number information and / or error correction information in the format-specific parameter attribute field. On the receiving side of the stream, the receiving process can be appropriately configured according to the description of the SDP object.

The technique according to the present disclosure is not limited to the above-described embodiment. It will be appreciated by those skilled in the art that these embodiments are merely exemplary and that various modifications are possible without departing from the scope and spirit of the present disclosure.

For example, the processing steps shown in the flowchart do not necessarily have to be executed in the order shown. For example, the processing steps may be executed in an order different from the illustrated order, or two or more processing steps may be executed in parallel. In addition, some processing steps may be deleted, and further processing steps may be added.

Further, the function of the node described in the present specification may be realized by software, hardware, or a combination of software and hardware. The program instructions of the computer programs that make up the software are stored, for example, in a non-temporary computer-readable storage medium inside or outside the node, read into the memory at run time, and executed by the processor.

Further, the technology described herein as being realized by a single device or a single node may be realized as a system by coordinating a plurality of devices or a plurality of nodes with each other.

Some or all of the above embodiments may also be described, but not limited to:

(Appendix 1)
A transmitter that transmits a broadcast signal stream that transmits different types of essence data with a single port number to the IP network of a broadcasting station,
A control unit that provides an SDP (Session Description Protocol) object that describes the attributes of the broadcast signal stream to other nodes.
With
The SDP object is one of compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. One or more are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.
Send node.

(Appendix 2)
The compression-related information is
Includes compression parameters that indicate whether the video essence data is compressed
When the compression parameter indicates that the video essence data is compressed, it further includes a codec parameter indicating a codec used when compressing the video essence data.
The transmitting node described in Appendix 1.

(Appendix 3)
The error correction information is
A type parameter indicating the error correction method applied to the essence data, and
The setting parameter indicating the setting value of the error correction method indicated by the type parameter, and the setting parameter.
The transmitting node according to Appendix 1 or Appendix 2, including.

(Appendix 4)
The transmitting node according to Appendix 3, wherein when the type parameter indicates XOR coding, the setting parameter includes a size parameter indicating an error correction block size.

(Appendix 5)
The transmitting node according to Appendix 3 or Appendix 4, wherein when the type parameter indicates Reed-Solomon coding, the configuration parameter includes a datagram number parameter indicating the number of datagrams corresponding to the processing unit of Reed-Solomon coding. ..

(Appendix 6)
The transmission node according to any one of Appendix 1 to 5, wherein the control unit provides the SDP object to the other node via a predefined application protocol interface for management.

(Appendix 7)
The transmission node according to any one of Supplementary notes 1 to 6, wherein the broadcast signal stream is an ARIB STD-B73 stream.

(Appendix 8)
The transmission node according to any one of Supplementary notes 1 to 7 and
A receiving node that receives the broadcast signal stream set up according to the description of the SDP object, and
Broadcasting system including.

(Appendix 9)
A control node that controls the transmission of a broadcast signal stream that transmits different types of essence data with a single port number from a transmitting node to a receiving node in the IP network of a broadcasting station.
A control unit that acquires an SDP (Session Description Protocol) object that describes the attributes of the broadcast signal stream from the transmitting node is provided.
The SDP object is one of compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. One or more are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.
Control node.

(Appendix 10)
Providing other nodes with SDP (Session Description Protocol) objects that describe the attributes of broadcast signal streams that transmit different types of essence data on a single port number.
To transmit the broadcast signal stream to the IP network of the broadcasting station,
Including
The SDP object is one of compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. One or more are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.
Transmission control method.

(Appendix 11)
To the processor of the transmitting node that transmits a broadcast signal stream that transmits different types of essence data on a single port number to the broadcaster's IP network.
To provide another node with an SDP (Session Description Protocol) object that describes the attributes of the broadcast signal stream.
To execute,
The SDP object is one of compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. One or more are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.
Computer program.

(Appendix 12)
To the processor of the transmitting node that transmits a broadcast signal stream that transmits different types of essence data on a single port number to the broadcaster's IP network.
To provide another node with an SDP (Session Description Protocol) object that describes the attributes of the broadcast signal stream.
To execute,
The SDP object is one of compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. One or more are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.
A non-temporary computer-readable storage medium that stores computer programs.

(Appendix 13)
A transmission control method for controlling transmission of a broadcast signal stream that transmits different types of essence data with a single port number from a transmitting node to a receiving node in the IP network of a broadcasting station.
Obtaining an SDP (Session Description Protocol) object that describes the attributes of the broadcast signal stream from the transmitting node,
Including
The SDP object is one of compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. One or more are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.
Transmission control method.

(Appendix 14)
To the processor of the control node that controls the transmission of the broadcast signal stream from the transmitting node to the receiving node, which transmits different types of essence data with a single port number in the IP network of the broadcasting station.
Obtaining an SDP (Session Description Protocol) object that describes the attributes of the broadcast signal stream from the transmitting node,
To execute,
The SDP object is one of compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. One or more are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.
Computer program.

(Appendix 15)
To the processor of the control node that controls the transmission of the broadcast signal stream from the transmitting node to the receiving node, which transmits different types of essence data with a single port number in the IP network of the broadcasting station.
Obtaining an SDP (Session Description Protocol) object that describes the attributes of the broadcast signal stream from the transmitting node,
To execute,
The SDP object is one of compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. One or more are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.
A non-temporary computer-readable storage medium that stores computer programs.

The technique according to the present disclosure can be used in a system for processing a broadcast signal, though not limited to the technology.

1,3 Broadcasting station system 10 IP domain 20 (20a to d) Broadcast signal processing node 60 (60a to d) Sender 65 (65a to c) Receiver 70 Common reference clock 72a Device internal clock 73a, 76a Media clock 74a, 77a RTP Clock 81,82 Essence separated stream 83 Essence mixed stream 100,200 Broadcast signal processing node 110 Device internal clock 112 Media clock 114 RTP clock 116 PTP processing unit 120, 210, 215 Communication unit (1st communication unit)
122 Transmitter 124 Receiver 130 Transmit Stream Processing 140 Receive Stream Processing 142 Transport Processing 144 Transport Header Removal 150 Essence Datagram Processing 152 Essence Header Removal 154 Video Essence Processing 156 Voice Essence Processing 158 Auxiliary Data essence processing unit 160, 220 Alignment unit 161a to d, 166a to d RTP packet 162a to d, 167a to d RTP header 163a to d, 168a to b Essence header 170 FEC datagram processing unit 180 Data processing unit 190 Control unit 230 Playback unit 240 Conversion unit 250 Second communication unit 300,500 Transmission node 311 SDP object 312 Session level section 313,318 Media level section 315 RTP map attribute field 316 Format specific parameter attribute field 317 Packet time attribute field 320 Communication unit 322,510 Transmitter 324 Receiver 390,520 Control 395 Storage 400,600 Control node 410 Communication 412 Transmitter 414 Receiver 420,610 Control 422 Information management 424 Stream control 430 Storage 450 Receiver

Claims (10)

A transmitter that transmits a broadcast signal stream that transmits different types of essence data with a single port number to the IP network of a broadcasting station,
A control unit that provides an SDP (Session Description Protocol) object that describes the attributes of the broadcast signal stream to other nodes.
With
The SDP object is one of compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. One or more are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.
Send node. The compression-related information is
Includes compression parameters that indicate whether the video essence data is compressed
When the compression parameter indicates that the video essence data is compressed, it further includes a codec parameter indicating a codec used when compressing the video essence data.
The transmitting node according to claim 1. The error correction information is
A type parameter indicating the error correction method applied to the essence data, and
The setting parameter indicating the setting value of the error correction method indicated by the type parameter, and the setting parameter.
The transmission node according to claim 1 or 2, wherein the transmission node includes. The transmission node of claim 3, wherein when the type parameter indicates XOR coding, the configuration parameter includes a size parameter indicating an error correction block size. 13. Sending node. The transmission node according to any one of claims 1 to 5, wherein the control unit provides the SDP object to the other node via a predefined application protocol interface for management. The transmission node according to any one of claims 1 to 6, wherein the broadcast signal stream is an ARIB STD-B73 stream. The transmitting node according to any one of claims 1 to 7 and
A receiving node that receives the broadcast signal stream set up according to the description of the SDP object, and
Broadcasting system including. A control node that controls the transmission of a broadcast signal stream that transmits different types of essence data with a single port number from a transmitting node to a receiving node in the IP network of a broadcasting station.
A control unit that acquires an SDP (Session Description Protocol) object that describes the attributes of the broadcast signal stream from the transmitting node is provided.
The SDP object is one of compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. One or more are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.
Control node. Providing other nodes with SDP (Session Description Protocol) objects that describe the attributes of broadcast signal streams that transmit different types of essence data on a single port number.
To transmit the broadcast signal stream to the IP network of the broadcasting station,
Including
The SDP object is one of compression-related information indicating whether the video essence data is compressed, audio channel number information related to the audio essence data, and error correction information indicating an error correction method applied to the essence data. One or more are included in the attribute field that describes the format-specific parameters of the broadcast signal stream.
Transmission control method.

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