KR101855327B1 - Apparatus and method for delivering multimedia data in hybrid network - Google Patents

Abstract

A method for transmitting media content in a multimedia system, the method comprising: generating at least one multimedia data packet comprising a packet header and a packet payload; transmitting the at least one multimedia data packet to a receiving entity ; The at least one multimedia data packet includes type information indicating whether data included in the packet payload is a complete data unit type, an indicator for identifying media data included in the packet payload and other media data, , And a flag indicating whether the data included in the packet payload includes a plurality of data units.

Description

[0001] APPARATUS AND METHOD FOR DELIVERING MULTIMEDIA DATA IN HYBRID NETWORK [0002]

The present invention relates to an apparatus and method for transmitting multimedia data in a hybrid network, and an apparatus and method for transmitting multimedia data using an MPEG Media Transport (MMT).

In recent multimedia services, a hybrid network for connecting a broadcasting network and a communication network at the same time, and an MMT technology for providing multimedia contents, applications and files with combined contents are considered.

The MMT technology relates to an MPEG-based multimedia transmission technology and can be used in place of an MPEG-2 TS (Transport Stream) for broadcasting and multimedia services such as a multi-function smart TV and a multi-view TV. It is possible to provide an efficient MPEG transmission technology in a multimedia service environment that changes based on IP. However, there is a problem that it is difficult to provide a service suitable for a hybrid network environment when multimedia data is transmitted in a hybrid network.

The present invention relates to an apparatus and method for transmitting multimedia data in a hybrid network.

The present invention also relates to an apparatus and method for transmitting multimedia data by generating MMT transport packet (TP) data in a hybrid network.

The present invention also relates to an apparatus and method for transmitting multimedia data by defining MMT TP data header information and payload data information.

The present invention also relates to an apparatus and method for transmitting multimedia data by defining information necessary for transmitting an MMT TP.

The present invention also relates to an apparatus and method for transmitting multimedia data by ensuring quality of experience (QoE) for an MMT TP.

A method according to an embodiment of the present invention comprises: A method for transmitting media content in a multimedia system, the method comprising: generating at least one multimedia data packet comprising a packet header and a packet payload; and transmitting the at least one multimedia data packet to a receiving entity ; The at least one multimedia data packet includes type information indicating whether data included in the packet payload is a complete data unit type, an indicator for identifying media data included in the packet payload and other media data, , And a flag indicating whether the data included in the packet payload includes a plurality of data units.

The present invention can provide header information and payload information of an MMT transmission packet for transmitting complex multimedia data in a hybrid network, and can provide a service suitable for a hybrid network environment by applying the MMT technology.

1 is a block diagram illustrating an apparatus for transmitting multimedia multimedia contents according to an exemplary embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In the complex network environment of the present invention, a connection structure between a server and a client is simultaneously provided to a client for a broadcast network (hereinafter referred to as broadcast) and a network for internet communication (hereinafter referred to as broadband) And a client is an environment in which services can be provided through a plurality of networks. In addition, the plurality of network environments include a plurality of connection environments of a broadcast, a broadcast environment, a broadband, and a broadband environment, and the two environments may be connected in a complex manner and include a wired or wireless network.

In addition, in the present invention, multimedia media contents include data such as audio, video and synchronized subtitles, multimedia contents that are played back with time characteristics such as images, and audio books, multimedia widgets, Is a content that can be used in combination depending on the relationship in which it is stored in the form in which it is embedded.

1 is a block diagram of an apparatus 10 for transmitting multimedia multimedia contents according to an exemplary embodiment of the present invention.

The apparatus 10 for transmitting multimedia multimedia contents according to an embodiment of the present invention can transmit multimedia multimedia contents using the MMT technology. The MMT transport layer can transmit multimedia contents according to data included in the multimedia contents. And is responsible for efficiently transmitting them. For this, the MMT transport layer may include a structure divided into common transmission information and characteristic transmission information.

Referring to FIG. 1, the MMT payload of the transmission apparatus 10 of the present invention includes a payload 150 for streaming data for real-time data transmission closely related to real-time broadcasting and time, And a payload 160 for file transfer. In addition, the streaming payload 150 may be configured using MMT (Media) Unit 110 or MMT MFU (Media Fragment Unit) 100 of the multimedia contents as a basic unit transmitted for real time data transmission have.

The file transfer payload 160 is used for non real-time data transfer. As a basic unit for transmission, an MMT Asset 120 (hereinafter referred to as an Asset) or an MMT Package 130 ) May be configured as a basic unit. The unit for encoding the multimedia contents may be composed of the MFU 100 or the M-Unit 110. When the MFU 100 is video capable of being decoded independently, one frame or frame of the encoding may be divided into a plurality of slice structures If configured, it means one Slice unit. In the case of video which can be independently decoded, the M-Unit 110 means a unit of encoding or a unit of GOP (Group of Picture) which is a coding handling unit capable of independently decoding. The structure of the MFU 100 or the M-Unit 110 can be determined in consideration of attributes and services of the multimedia media.

Asset 120 is a continuous stream of M-units 110 configured with the same media type and Package 130 is a bundle of a single Asset 120 or a plurality of Assets 120, Here, the package 130 includes additional information for a service in a single form of a single Asset 120 or a bundle of a plurality of Assets 120. In this case, the additional information may be a composite multimedia And transmission environment information considering a complex network environment regarding transmission configuration request information, transmission request bandwidth, loss possibility, delay time availability, and the like.

In the case of a service requesting real-time transmission such as real-time broadcasting, the transmission apparatus 10 of the present invention can transmit multimedia contents by configuring a payload in units of MFU 100 and M-Unit 110, In the case of a service requiring non-real time transmission such as a VoD (Video on Demand) service, a payload can be configured in units of an Asset 120 and a Package 130 to transmit multimedia contents. In addition, the streaming payload 150 for real-time data transmission and the file transmission payload 160 for non-real-time data transmission are provided to the MMT transmission packet 140 operating in the TCP / UDP 170 environment, which is an IP- Or may be included in the payload of the RTP 180, which is an Internet protocol, and transmitted to the terminal.

Meanwhile, the MMT payload, such as the streaming payload 150 and the file transfer payload 160, may be composed of a header area including configuration information used according to the transmission environment and a data area including transmission data, Data may be transmitted in a single payload or multiplexed to a plurality of payloads depending on the transmission environment, and the payload for multiplexing may be separated into two or more fragments in a certain unit.

In addition, it is possible to provide a predetermined unit of interleaving function in consideration of a specific transmission function. The payload can be defined as a simple and effective unit structure of a transmission layer as much as possible.

In the present invention, the header area of the general MMT payload for transmitting the multimedia contents in the complex network environment can be configured as shown in [Table 1].

Payload type Fragmentation indicator Sequence Number Sequence Number Length Length Timestamp Timestamp Timestamp Multiplex Info. Aggregation Info. Payload Configuration

i) Payload Type

The payload type indicates the data configuration type of the payload, and specifically, the type and configuration information of the transmitted data. At this time, the type of data and the configuration information according to the type of the data are the type of the payload data, that is, a complete M-Unit 110, a simple fragment of the M-Unit 110, a complete MFU 100, 100) are aggregated. In addition, the payload includes a parameter for distinguishing whether the type of data to be transmitted is transmission data or control data, and includes delimiter information for identifying the type of transmission data.

For example, the data to be transmitted includes information on a media type such as video, audio, image, and text, and a codec type related thereto. Additional data types may include data types transmitted in a payload, data types of a single time stamp, whether or not they represent multiple time stamps, not time information, time stamp).

ii) Fragmentation indicator

The fragment indicator indicates information indicating the beginning, middle, and end of the payload when the payload being transmitted is divided into fragments. For example, when the data of the corresponding payload is the MFU 100 of the media, the client can handle the payload as a bundle of data processing using this information and transmit it. In addition, if the last fragment of the payload is received, the terminal can construct a complete payload and proceed with the decoding process.

In the case of live streaming or VoD transmission, the payload for transmission may be a single MFU (100) or M-Unit (110) size, and in the case of file transmission, . In addition, it can indicate that the payload is chained through such information, and can provide a multiplexing function for a plurality of MFUs 100 or M-units 110 through the information configuration. It is possible to transmit a plurality of M-units 110 or MFUs 100 within one payload.

iii) Sequence Number

The sequence number is incremented, transmitted, and used by the receiver to detect payload loss, one for each payload. The MMT does not perform any action on the MMT packet loss, which is left to the application to perform the desired operation. The MMT transmission does not provide a guarantee of transmission, but the presence of a sequence number makes it possible to detect a lost payload.

iv) Length:

This field indicates the length of the payload (header and data).

v) Time stamp:

This field is used to confirm the playback point of the payload and indicates the payload for real-time transmission.

vi) Multiplexing information

This field information indicates that the transmission units included in the payload are multiplexed in a multiplexed manner. For example, the field information indicates that a plurality of M-Units are included in the payload. Specific information includes the number of multiplexed constituent units, the size of each constituent unit, and the offset of the constituent units.

vii) Aggregation

This field indicates the setting information of the payload, and the information of this field depends on the payload type. If the corresponding payload is in a fragmented state, the information indicates the number of remaining fragmented payloads. In the aggregated state, the M-Unit 110 or the MFU 100).

viii) Payload Configuration

The configuration of the payload needs to be efficiently configured considering various transmission environments and services, and it can be configured to be divided into information applicable to all payloads and information applicable only to a specific payload. Also, very few configurations are typically needed for a particular payload, but in the present invention, certain modes are defined for a particular use, except for a dedicated receiver, in order to allow simple payload configuration .

For example, MMT streams mode, file delivery modes may be considered, as well as a generic mode that may be used to transmit certain MMT content. Also, an auxiliary field may be configured to transmit certain data to anticipate the need for the transmission of information relating to any additional systems in the future. Specifically, the auxiliary field includes a function providing identifier capable of providing a function for loss control, lossy reconstruction encoding information, information for requesting automatic error loss recovery, a minimum memory buffer size to be provided by the terminal, Buffer size, critical transmission data, maximum loss tolerance, maximum allowed packet delay time, average packet delay time, and synchronization code information for network synchronization.

Next, a case of transmitting data using the MMT payload configured as described above will be described.

First, the multi-content data transmission for real-time broadcasting will be described. The terminal is connected to a single server or a plurality of servers in a broadcast and broadband network environment. Through the network environment, Service, i.e., subtitles of different languages and user audio commentary information to a client having a large display device in real time.

In this case, the M-Unit 110 or the MFU 100, which can be handled as a basic transmission unit among the data units constituting the real-time broadcasting contents, can be transmitted in a single payload or a plurality of payloads. In the case of transmitting the M-Unit 110 as a basic transmission unit, one GOP (Group of Picture) in the case of video data can be treated as an M-Unit 110 and transmitted as a single payload. One GOP data is the largest video unit that can be independently decoded. In the case of H.264 video encoding, there is a slice that can be independently decoded. In this embodiment, the slice can be used as a minimum unit of the MFU 100 .

In the case where one GOP encoded with H.264 is configured as a payload for transmission using the M-Unit 110, it can be configured as shown in [Table 2]. Usually, one GOP size corresponds to a payload size , It can be composed of several payloads. In addition, the payload configured as shown in [Table 2] can be represented in the same structure not only when the unit data of the payload is the M-Unit 110, but also when the payload is the MFU 100.

- payload type: H.264 Video GOP
- fragmentation indicator: on
- sequence number: increases from 0.
- length: 1024 (byte) Indicates the length of the payload.
- timestamp: The representative value of the playback time of the corresponding GOP is indicated by the NTP timestamp.
- multiplexing information: off
- aggregation: 5 The end payload of the corresponding GOP is completed after five.
- payload configuration: ALFEC indicator, DRM indicator
- payload

Next, a case of transmitting progressive download contents by non-real-time broadcasting to a service transmitted from a plurality of servers will be described. The basic unit structure of the transmission data of the MMT payload for non real-time data transmission can be divided into Asset 120 or Package 130, and the payload type can be classified according to the type of each transmission data . Also, since the transmission characteristic of the corresponding data is considered to be non-real time, attribute information related to time can be excluded from the corresponding payload data, which can provide efficiency in mass data transmission. Further, additional information necessary for loss recovery can be described through auxiliary fields according to characteristics of transmission data sensitive to loss, and information of auxiliary fields can provide data structure information on loss recovery rather than real-time transmission.

In the case of multimedia multimedia contents and non real-time multimedia contents transmission for real-time broadcasting, the terminal is connected to a single server or a plurality of servers in a broadcast and broadband network environment. And provide a user-added service related to a soccer game to a client having a large-screen display device in real time.

It may be considered that the basic unit data of the transmission structure is a combination of the MFU 100 and the M-Unit 110 which are real-time transmission data and the Asset 120 and the Package 130 which are lossless transmission data. The additional information may describe information about the transmission structure through multiplexing information. This is done by identifying the corresponding data information through the multiplex type which is the multiplex structure information of the corresponding transmission data unit, the offset of the transmission data unit, the length, and the ID of the transmission data unit. It is possible to provide division unit information.

Meanwhile, the MMT payload according to an exemplary embodiment of the present invention may be transmitted by an MMT transmission packet 140 or an RTP (Real Time Transport Protocol) packet 180, which is an Internet protocol. A data packet structure for payload transmission, which performs packetization of data in a payload division unit and transmits the packets to a network. Further, the MMT transmission packet 140 includes additional information related to transmission in a header area. The additional information includes a packet ID, a packet number, a Flow ID for providing QoS (Quality of Service), transmission time and control information You can consider a possible timestamp.

The additional information will be described in detail as follows.

i) Packet ID

The packet ID represents the identifier of the MMT packet 140, which is the identification value assigned by the sender in assembling the fragments of the datagram in the lower protocol.

ii) Sequence Number

The sequence number is a unique identification number of a packet to be transmitted. The receiving terminal can determine whether the packet is lost or not and can perform a packet sorting function according to the sequence number. Sequence number information can also be sequentially increased.

iii) flow label (flowLabel)

The flow label identifies the specific QoS required for each flow required for each data transmission. For example, there are a packet type (Type of Packet), a delay (Delay), a throughput (Throughput), a synchronization parameter, and the like. Specifically, as shown in [Table 3] And can be represented in detail.

- Type of Packet

This field indicates the type information of the packet for the MMT transmission packet 140, and 3 bits can be used.

Bits 0-2 Bit rate 111 Constant Bit Rate (CBR) 110 Real-Time Variable Bit Rate (rt-VBR) 101 Non-Real-Time Variable Bit Rate (nrt-VBR) 100 Available Bit Rate (ABR) 011 Unspecified Bit Rate (UBR) 010 Reserved 001 Reserved 000 Reserved

- Delay

This field indicates the degree of delay, and one bit can be used.

bit 3 Delay 0 Normal delay One Low delay

- Throughput

This field indicates the degree of throughput, and one bit can be used.

Bit 4 Throughput 0 Normal throughput One High throughput

- Synchronization parameter

This field indicates synchronization information, and 3 bits can be used.

Bit 5 Synchronization 0 no relationship One relationship with another packet bits 6-7 Reserved for future use

iv) Packet configuration information

The packet configuration information provides configuration information for accessing the flexible and efficient mechanism of the corresponding service class in the transmission of the packetized data. These parameters are used to measure the QoS and end-to-end network performance of the connection at the network layer.

The network must guarantee the negotiated QoS by satisfying a specific value of these parameters, and the corresponding parameter information is available as a reference to the QoS field parameter of the IPv4 tos field, IPv6. [Table 7] and [Table 8] show the structure of concrete parameters.

- Delay (range)

This field indicates the maximum end-to-end latency associated with the transmission. Based on the delay information, the receiver can easily determine whether or not the delay time is exceeded and reduce the response time for the delay time reduction effort.

Bit 0-2 Delay 111 500ms 110 1 sec 101 5sec 100 10sec 011 unlimited 010 001 000

- AU loss rate (%)

Represents a loss ratio of a transmission packet. The percentage of this represents the allowance of packets per second. Based on the information, the receiving side can quickly determine whether or not to cope with the packet loss recovery function.

Bit 3-4 AULR 111 0% 110 10% 101 20% 100 30% 011 50% 010 not specified 001 000

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims, and equivalents thereof.

100: MMT MFU 110: MMT M-Unit
120: MMT Asset 130: MMT Package
140: MMT Packet 150: payload for streaming
160: Payload for file transfer 170: TCP / UDP
180: RTP

Claims (3)

A method for transmitting media data in a multimedia system,
Generating at least one multimedia data packet including a packet header and a payload;
Transmitting the at least one multimedia data packet to a receiving entity;
Wherein the at least one multimedia data packet comprises:
Type information including a value indicating whether data included in the payload is a complete type of data unit, an indicator used to distinguish the media data from other media data, aggregated data units And a flag indicating whether the payload is included in the payload.
The method according to claim 1,
And wherein if the value indicates that the data unit contained in the payload is incomplete, then the value further identifies the location for the incomplete portion of the data unit.
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