WO2013055168A1

WO2013055168A1 - Method for transmitting media data interlinked with composition information and transmission characteristics information via a heterogeneous ip network

Info

Publication number: WO2013055168A1
Application number: PCT/KR2012/008351
Authority: WO
Inventors: 배성준
Original assignee: 한국전자통신연구원
Priority date: 2011-10-13
Filing date: 2012-10-12
Publication date: 2013-04-18

Abstract

The present invention relates to a method for transmitting media data via a heterogeneous IP network, in which temporal or spatial relationships between MMT assets and transmission characteristics of MMT assets are formed into separate messages in composing MMT assets, thus efficiently transmitting media streaming.

Description

Method of transmitting media data linked with composition information and transmission characteristic information through heterogeneous IP network

The present invention relates to a method of transmitting media data, and more particularly, to a method of transmitting encoded media data in a system for transmitting encoded media data through a heterogeneous IP network.

The MPEG-2 system has standardized MPEG-2 Transport Stream (TS) technology as a standard for packetization, synchronization, and multiplexing for transmitting AV (Audio Video) content in a broadcasting network. However, MPEG-2 TS is inefficient in a new environment in which the network is All IP (Internet Protocol).

Therefore, a new media transmission technology is required in a system for transmitting encoded media data through a heterogeneous IP network in consideration of the new media transmission environment and the expected media transmission environment.

An object of the present invention is to provide a method for transmitting media data through a heterogeneous IP network for efficiently transmitting media streaming by configuring a temporal or spatial relationship between MMT assets in a separate message.

It is also an object of the present invention to provide a method for transmitting media data through a heterogeneous IP network for efficiently transmitting media streaming by configuring a transmission characteristic of the MMT asset as a separate message in the configuration of the MMT asset.

The present invention provides a method for transmitting encoded media data in a system for transmitting coded media fragment data through a heterogeneous IP network, wherein the media codec layer is independent of a specific media codec. Receiving a media unit (MU) having a format; Encapsulating the generated media unit to generate an MMT asset; Generating an MMT package by encapsulating the generated MMT asset; Receiving the generated MMT package and generating an MMT payload format; And generating an MMT transport packet by receiving the generated MMT payload format, wherein the MMT asset is an MMT asset indicator which is an index for distinguishing the MMT asset from other MMT assets; And an MMT composition information indicator for storing an index of MMT Composition Information (MMT CI) referred to by the MMT asset.

In addition, generating an MMT asset by encapsulating the generated media unit may include generating MMT composition information representing information on at least one of temporal and spatial relationships between the MMT assets. The method may further include generating an MMT package by encapsulating the generated MMT asset, and generating an MMT package by encapsulating the generated MMT asset and the MMT composition information. An encoded media data transmission method is provided.

The MMT composition information may include information on at least one of temporal and spatial relationships between the MMT assets and the MMT composition information indicator which is an index for distinguishing the MMT composition information from other MMT composition information. The MMT asset and the MMT composition information provides a method for transmitting the encoded media data, characterized in that the relationship is maintained as the MMT composition information indicator.

The MMT composition information may include a composition information header part and a composition information data part, wherein the composition information data part includes information on at least one of temporal and spatial relationships between the MMT assets, and the composition information header part may include the MMT composition The MMT composition information indicator including the MMT composition information indicator, which is an index for distinguishing information from other MMT composition information, wherein the MMT asset and the MMT composition information maintain the association with the MMT composition information indicator. To provide.

The MMT asset may further include an indicator indicating the number of the media units stored in the MMT asset.

The MMT asset includes a header portion and a data portion, the data portion includes the media unit, and the header portion is an MMT asset indicator and the MMT asset that is an index for distinguishing the MMT asset from other MMT assets. A coded media data transmission method comprising an MMT composition information indicator for storing an index of the MMT composition information referred to.

In addition, the present invention provides a method for transmitting encoded media data in a system for transmitting coded media fragment data over a heterogeneous IP network, the method comprising: transmitting a media codec layer to a specific media codec; Receiving a media unit (MU) having an independent format; Encapsulating the generated media unit to generate an MMT asset; Generating an MMT package by encapsulating the generated MMT asset; Receiving the generated MMT package and generating an MMT payload format; And generating an MMT transport packet by receiving the generated MMT payload format, wherein the MMT asset is an MMT asset indicator which is an index for distinguishing the MMT asset from other MMT assets; An MMT transport characteristic indicator which stores an index of an MMT transport characteristic (MMT TC) referred to by the MMT asset is provided.

In addition, generating the MMT asset by encapsulating the generated media unit may further include generating an MMT transport characteristic (MMT TC) indicating information related to the transmission of the MMT asset. The generating of the MMT package by encapsulating the generated MMT asset may include generating the MMT package by encapsulating the generated MMT asset and the MMT transmission characteristic. Provided are media data transmission methods.

The MMT transmission characteristic may include information related to the transmission of the MMT asset and the MMT transmission characteristic indicator which is an index for distinguishing the MMT transmission characteristic from other MMT transmission characteristics. The feature provides a method for transmitting encoded media data, wherein the feature maintains relevance as the MMT transmission feature indicator.

The MMT transmission characteristic information may include a transmission characteristic header unit and a transmission characteristic data unit, the transmission characteristic data unit may include information related to the transmission of the MMT asset, and the transmission characteristic header unit may transmit the MMT transmission characteristic different from the MMT transmission characteristic. Including the MMT transmission characteristic indicator which is an index to distinguish from the characteristic, the MMT asset and the MMT transmission characteristic maintains the association as the MMT transmission characteristic indicator provides an encoded media data transmission method.

The MMT asset includes a header portion and a data portion, the data portion includes the media unit, and the header portion is an MMT asset indicator and the MMT asset that is an index for distinguishing the MMT asset from other MMT assets. Provided is a coded media data transmission method comprising an MMT transmission characteristic indicator for storing an index of the MMT transmission characteristic referred to.

In another aspect, the MMR asset further comprises an MMT transport characteristic indicator for storing an index of the MMT transport characteristics (MMT TC) referenced by the MMT asset. Provide a transmission method.

In addition, generating the MMT asset by encapsulating the generated media unit may further include generating an MMT transport characteristic (MMT TC) indicating information related to the transmission of the MMT asset. The generating of the MMT package by encapsulating the generated MMT asset and the MMT composition information may include generating the MMT package by encapsulating the generated MMT asset, the MMT composition information, and the MMT transmission characteristic. It provides a method of transmitting the encoded media data, characterized in that the step of generating.

The MMT asset includes a header portion and a data portion, the data portion includes the media unit, and the header portion is an MMT asset indicator that is an index for distinguishing the MMT asset from another MMT asset. An MMT composition information indicator for storing an index of the MMT composition information to be referred to, and an MMT transmission characteristic indicator for storing an index of the MMT transmission characteristic referred to by the MMT asset, the encoded media data transmission method .

The media data transmission method through the heterogeneous IP network according to the present invention has an effect of efficiently transmitting media streaming by simplifying the structure of the MMT asset by configuring a temporal or spatial relationship between MMT assets in a separate message. .

In addition, the present invention provides a method of transmitting media data through a heterogeneous IP network for efficiently transmitting media streaming by configuring the transmission characteristics of the MMT asset in a separate message in the configuration of the MMT asset.

1 is a conceptual diagram illustrating an MMT hierarchical structure.

2 is a conceptual diagram illustrating a format of unit information (or data or packet) used for each layer of the MMT hierarchical structure.

3 is a conceptual diagram of an MMT package configuration.

4 is a flowchart illustrating a method of transmitting encoded media fragment data according to an embodiment of the present invention.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description.

However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, the meaning of the term is defined as follows.

A system for transmitting encoded media data through a heterogeneous IP network is referred to as an MMT (MPEG Media Transport) system.

The content component or media component is defined as a media of a single type or a subset of the media of a single type. , Video tracks, movie subtitles, or a video enhancement layer of video.

Content is defined as a set of content components, and may be, for example, a movie or a song.

A presentation is defined as an operation performed by one or more devices to allow a user to experience one content component or one service (eg, watch a movie).

A service is defined as one or more content components that are transmitted for presentation or storage.

Service information is defined as metadata describing one service, characteristics and components of the service.

An access unit (AU) is the smallest data entity and may have time information as an attribute.

If coded media data for which decoding and presentation time information is not specified is relevant, the AU is not defined.

An MMT asset is a logical data entity consisting of at least one MPU with the same MMT asset ID or a specific chunk of data with a format defined by other standards. The MMT asset is the largest data unit to which the same composition information and transmission characteristics apply.

MMT Asset Delivery Characteristics (MMT-ADC) is a description related to QoS requirements for delivering MMT assets. MMT-ADC is expressed without knowing the specific transmission environment.

MMT Composition Information (MMT CI) describes spatial and temporal relationships between MMT assets.

Media Fragment Unit (MFU) is a general container, which is independent of any particular codec, and accommodates encoded media data that can be consumed independently by a media decoder. It has information that is less than or equal to the access unit (AU) and can be used at the transport layer.

An MMT package is a collection of logically structured data and includes at least one MMT asset, MMT composition information, MMT asset asset, and descriptive information.

The MMT packet is a format of data generated or consumed by the MMT protocol.

The MMT payload format is a format for payload of an MMT package or MMT signaling message to be delivered by an MMT protocol or an internet application layer protocol (eg, RTP).

The Media Processing Unit (MPU) is a generic container that is independent of any particular media codec and contains at least one AU and information related to additional transmission and consumption. For non-temporal data, the MPU accepts a portion of data that does not fall within the AU range. MPU is encoded media data that can be processed completely and independently. In this context, processing means encapsulation or packetization into an MMT package for transmission.

Non-timed data defines all data elements that are consumed without specifying time. Non-timed data can have a time range within which the data can be executed or started.

Timed data defines data elements associated with a particular time to be decoded and presented.

Media data refers to data elements including both non-timed data and timed-data.

The media unit refers to a container including a media fragment unit (MFU) or a media processing unit (MPU).

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. In the following description of the present invention, the same reference numerals are used for the same elements in the drawings and redundant descriptions of the same elements will be omitted.

1 is a conceptual diagram illustrating an MMT hierarchical structure.

Referring to FIG. 1, the MMT layer includes an encapsulation layer, a delivery layer, and an S layer. The MMT layer operates on a transport layer.

The encapsulation layer (E-layer) may be responsible for, for example, packetization, fragmentation, synchronization, multiplexing, and the like of transmitted media.

The encapsulation functional area defines the logical structure of the format of the media content, the MMT package, and the data units to be processed by the MMT compliant entity. In order to provide the necessary information for adaptive delivery, the MMT package specifies the components that contain the media content and the relationships between them. The format of the data units is defined to encapsulate the encoded media to be stored or transmitted in the payload of the transport protocol and to be easily converted between them.

Encapsulation layer (E-layer), as shown in Figure 1, MMT E.1 Layer (MMT E.1 Layer), MMT E.2 Layer (MMT E.2 Layer) and MMT E.3 Layer (MMT) E.3 Layer).

The E.3 layer encapsulates a Media Fragment Unit (MFU) provided from the Media Codec (A) layer to create a Media Processing Unit (MPU).

Encoded media data from the upper layer is encapsulated in MFU. The type and value of the encoded media can be abstracted to allow the MFU to be generally used in a particular codec technology. This allows the lower layer to process the MFU without access to the encapsulated encoded media. The lower layer retrieves the required encoded media data from the network or storage buffer and sends it to the media decoder. The MFU has enough information media subunits to perform this operation.

The MFU may have a format, independent of any particular codec, that can carry data units that can be consumed independently in the media decoder. The MFU can be, for example, a picture or slice of the video.

One or a group of multiple MFUs that can be independently transmitted and decoded create an MPU. Non-temporal media that are independently transportable and executable also create an MPU. MPUs describe internal structures such as the arrangement and pattern of MFUs that allow for quick access and partial consumption of MFUs.

The E.2 layer encapsulates the MPUs created in the E.3 layer to generate MMT assets.

An MMT asset is a data entity consisting of one or more MPUs from a single data source, and is a data unit in which composition information (CI) and transport characteristics (TC) are defined. Multiplexed by load format and transmitted by MMT protocol. MMT assets can correspond to packetized elementary streams (PES), for example video, audio, program information, MPEG-U widgets, JPEG images, MPEG 4 file format, M2TS (MPEG transport stream), etc.

The E.1 layer creates an MMT package by encapsulating the MMT asset generated in the E.2 layer.

The MMT asset is packaged with MMT composition information (MMT-CI) for later response of the same user experience together or separately with other functional areas—transmission area and signal area. The MMT package is also packaged with a transmission characteristic that selects an appropriate transmission method for each MMT asset to satisfy the haptic quality of the MMT asset.

The MMT package may be composed of one or more MMT assets together with additional information such as composition information and transport characteristics. Composition information includes information about a relationship between MMT assets, and when one content consists of a plurality of MMT packages, it indicates a relationship between a plurality of MMT packages. It may further include information. The transport characteristics may include transmission characteristic information necessary for determining a delivery condition of an MMT asset or an MMT packet, and may include, for example, a traffic description parameter and a QoS descriptor. ) May be included. The MMT package may correspond to a program of MPEG-2 TS.

The delivery layer may perform, for example, network flow multiplexing, network packetization, and QoS control of media transmitted through a network.

The delivery functional area defines the application layer protocol and format of the payload. The application layer protocol in the present invention provides enhanced features for the delivery of MMT packages as compared to conventional application layer protocols for the transmission of multimedia including multiplexing. The payload format is defined to carry coded media data regardless of the media type or encoding method.

The transport layer (D-layer), as shown in Figure 1, MMT D.1 Layer (MMT D.1 Layer), MMT D.2 Layer (MMT D.2 Layer) and MMT D.3 Layer (MMT) D.3 Layer).

The D.1 layer receives the MMT package generated in the E.1 layer and generates an MMT payload format. The MMT payload format is a payload format for carrying MMT assets and for transmitting information for consumption by the MMT application protocol or other existing application transport protocol such as RTP. The MMT payload may include a fragment of the MFU along with information such as AL-FEC.

The D.2 layer receives the MMT payload format generated in the D.1 layer and generates an MMT transport packet or an MMT packet. The MMT transport packet or MMT packet is a data format used in an application transport protocol for MMT.

D.3 layer (D.3-layer) supports QoS by providing the function of exchanging information between layers by cross-layer design. For example, the D.3 layer may perform QoS control using QoS parameters of the MAC / PHY layer.

The S layer performs a signaling function. For example, signaling functions for session initialization / control / management of transmitted media, server-based and / or client-based trick modes, service discovery, synchronization, etc. Can be done.

The signaling functional area defines the format of the message that manages the delivery and consumption of the MMT package. The message for consumption management is used to transmit the structure of the MMT package, and the message for delivery management is used to transmit the structure of the payload format and the configuration of the protocol.

As illustrated in FIG. 1, the S layer may include an MMT S.1 layer and an MMT S.2 layer.

S.1 layer includes service discovery, media session initialization / termination of media, media session presentation / control of media, delivery (D) layer and encapsulation (E). The interface function with the layer can be performed. The S.1 layer may define the format of control messages between applications for media presentation session management.

The S.2 layer is responsible for flow control, delivery session management, delivery session monitoring, error control, and hybrid network synchronization control. It is possible to define the format of the control message exchanged between delivery end-points of the D-layer.

The S.2 layer supports delivery session establishment and release, delivery session monitoring, flow control, error control, resource scheduling for established delivery sessions, and synchronization in a complex delivery environment to support the behavior of the delivery layer. Signaling for adaptive delivery, and signaling for adaptive delivery. Required signaling may be provided between a sender and a receiver. That is, the S.2 layer may provide signaling required between the sender and the receiver in order to support the operation of the transport layer as described above. In addition, the S.2 layer may be responsible for interfacing with the transport layer and the encapsulation layer.

FIG. 2 illustrates a format of unit information (or data or packet) used for each layer of the MMT hierarchical structure of FIG. 1.

The media fragment unit (MFU) 130 may include coded media fragment data 132 and a media fragment unit header (MFUH) 134. The media fragment unit 130 has a general container format independent of a specific codec and may carry the smallest data unit that can be consumed independently in a media decoder. The MFUH 134 may include additional information such as media characteristics-for example, loss-tolerance. MFU) 130 may be, for example, a picture or slice of a video.

The Media Fragment Unit (MFU) may define a format that encapsulates a portion of the AU in the transport layer to perform adaptive transmission in the range of the MFU. The MFU may be used to transmit certain types of encoded media so that portions of the AU can be independently decoded or discarded.

The MFU has an identifier for distinguishing one MFU from other MFUs and may have general relationship information between MFUs in a single AU. The dependency relationship between MFUs in a single AU is described, and the relative priority of the MFUs can be described as part of such information. The information can be used to handle the transmission at the lower transport layer. For example, the transport layer may omit the transmission of MFUs that may be discarded to support QoS transmission in insufficient bandwidth. Detailed description of the MFU structure will be given later.

The MPU is a collection of media fragment units including a plurality of media fragment units 130. The MPU may have a general container format independent of a specific codec and may include media data equivalent to an access unit. The MPU may have a timed data unit or a non-timed data unit.

MPU is data that is independently and completely processed by an entity following the MMT, and the processing may include encapsulation and packetization. An MPU may consist of at least one MFU or have a portion of data having a format defined by another standard.

A single MPU may accommodate the integral number or non-time data of at least one AU. For time data, an AU may be delivered from at least one MFU, but one AU may not be divided into multiple MPUs. In non-time data, one MPU receives a portion of non-time data that has been independently and completely processed by an entity that complies with the MMT.

An MPU can be uniquely identified within an MMT package with a sequence number and an associated asset ID that distinguishes it from other MPUs.

The MPU may have at least one random access point. The first byte of the MPU payload can always start with a random access point. In time data, this fact means that the decoding order of the first MFU in the MPU payload is always zero. In the time data, the presentation period and decoding order of each AU can be sent to inform the presentation time. The MPU does not have its initial presentation time, and the presentation time of the first AU of one MPU may be described in the composition information. The composition information may specify the first presentation time of the MPU. Details will be described later.

The MMT asset 150 is a collection of MPUs composed of a plurality of MPUs. The MMT asset 150 is a data entity composed of multiple MPUs (timed or non-timed data) from a single data source, and the MMT asset information 152 is an asset packaging metadata (Asset). additional information such as packaging metadata) and data type. MMT asset 150 may include, for example, video, audio, program information, MPEG-U widgets, JPEG images, MPEG 4 FF (File Format), packetized elementary streams (PES), and MPEG transport (M2TS). streams).

MMT Assets (MMT Assets) are logical data entities that contain encoded media data. The MMT asset may be composed of an MMT asset header and encoded media data. The encoded media data may be a collective reference group of MPUs with the same MMT asset ID. Types of data that can be individually consumed by an entity directly connected to the MMT client may be considered as separate MMT assets. Examples of data types that can be considered as individual MMT assets include MPEG-2 TS, PES, MP4 files, MPEG-U Widget Package, and JPEG files.

The encoded media of the MMT asset may be time data or non-time data. Temporal data is audiovisual media data that requires synchronized decoding and presentation of specific data at specified times. Non-timed data is data of a data type that can be decoded and provided at any time in accordance with the provision of a service or user interaction.

A service provider may create a multimedia service by integrating MMT assets and putting MMT assets on a space-time axis.

The MMT package 160 is a collection of MMT assets including one or more MMT assets 150. MMT assets in an MMT package may be multiplexed or concatenated.

The MMT package is a container format for MMT asset and configuration information. The MMT package provides a repository of MMT assets and configuration information for the MMT program.

The MMT program provider generates configuration information by encapsulating the encoded data into MMT assets and describing the temporal and spatial layout of the MMT assets and their transmission characteristics. MU and MMT assets can be sent directly in the D.1 payload format. The configuration information may be sent by the C.1 Presentation Session Management message. However, MMT program providers and clients that allow relaying or future reuse of MMT programs store them in MMT package format.

In parsing the MMT package, the MMT program provider determines which transmission path (eg, broadcast or broadband) the MMT asset will be provided to the client. Configuration information in the MMT package is transmitted in a C.1 presentation session management message along with transmission related information.

The client receives the C.1 Presentation Session Management message to know which MMT programs are available and how to receive the MMT assets for the corresponding MMT program.

The MMT package can also be transmitted by the D.1 payload format. The MMT package is packetized and delivered in D.1 payload format. The client receives the packetized MMT package and configures all or part of it, where it consumes the MMT program.

The package information 165 of the MMT package 160 may include configuration information. The configuration information may include additional information such as a list of MMT assets, package identification information, composition information 162, and transport characteristics 164. Composition information 162 includes information about a relationship between MMT assets 150.

The composition information 162 may further include information for indicating a relationship between a plurality of MMT packages when one content includes a plurality of MMT packages. Composition information 162 may include information about temporal, spatial and adaptive relations in an MMT package.

Like information to assist in the transmission and presentation of the MMT package, Composition Information in the MMT provides information about the spatial and temporal relationships between MMT assets in the MMT package.

MMT-CI is an explanatory language that extends HTML5 to provide such information. As HTML5 is designed to describe page-based presentations of text-based content, MMT-CI mainly represents spatial relationships between sources. In order to support the presentation of the temporal relationship between MMT assets, information related to MMT assets in an MMT package, such as presentation resources, time information for determining the order in which MMT assets are sent and consumed, and various MMT assets are consumed in HTML5. It can be extended to have additional properties of media elements. Detailed description will be described later.

The transport characteristics information 164 may include information on transmission characteristics and may provide information necessary for determining a delivery condition of each MMT asset (or MMT packet). The transmission characteristic information may include a traffic description parameter and a QoS descriptor.

The traffic description parameter may include bitrate information, priority information, or the like for the media fragment unit (MFU) 130 or the MPU. The bitrate information is for example information about whether the MMT asset is Variable BitRate (VBR) or Constant BitRate (CBR), guaranteed bitrate for the Media Fragment Unit (MFU) (or MPU). ), The maximum bit rate for the media fragment unit (MFU) (or MPU). The traffic description parameter may be used for resource reservation between servers, clients, and other components on a delivery path, for example, maximum size information of a media fragment unit (MFU) (or MPU) in an MMT asset. It may include. The traffic description parameter may be updated periodically or aperiodically.

The QoS descriptor includes information for QoS control and may include, for example, delay information and loss information. The loss information may include, for example, a loss indicator of whether delivery loss of the MMT asset is allowed or not. For example, a loss indicator of '1' may indicate 'lossless', and a '0' indicates 'lossy'. The delay information may include a delay indicator used to distinguish the sensitivity of the transmission delay of the MMT asset. The delay indicator may indicate whether the type of the MMT asset is conversation, interactive, real time, and non-realtime.

One content may consist of one MMT package. Alternatively, one content may consist of a plurality of MMT packages.

When one content consists of a plurality of MMT packages, composition information or composition information indicating temporal, spatial, and adaptive relations between the plurality of MMT packages ( configuration information) may exist inside one MMT package or outside the MMT package.

For example, in the case of hybrid delivery, some of the content components are transmitted through a broadcast network and the rest of the content components are transmitted through a broadband network. Can be. For example, in the case of a plurality of audio visual streams constituting one multi-view service, one stream may be transmitted to a broadcasting network and the other stream may be transmitted to a broadband network, and each AV stream may be multiplexed and transmitted to a client terminal. Can be individually received and stored. Alternatively, there may be a scenario in which application software such as a widget is transmitted to a broadband network and an AV stream (AV program) is transmitted to an existing broadcasting network.

In the multi-view service scenario and / or widget scenario as described above, the entire plurality of AV streams may be a single MMT package, and in this case, one of the plurality of streams may be stored in only one client terminal. The storage content becomes part of the MMT package, and the client terminal needs to rewrite the composition information or the configuration information, and the rewritten content becomes a new MMT package independent of the server. .

In the multi-view service scenario and / or widget scenario as described above, each AV stream may be one MMT package, and in this case, a plurality of MMT packages constitute one content, and storage Storage is recorded in units of MMT packages and requires composition information or configuration information indicating a relationship between MMT packages.

The composition information or configuration information included in one MMT package may refer to an MMT asset in another MMT package, and may also refer to the outside of an MMT package that refers to the MMT package in an out-band situation. I can express it.

Meanwhile, in order to inform the client terminal of a list of MMT assets 160 provided by a service provider and a possible path for delivery of the MMT package 160, the MMT package 160 is controlled through a control (C) layer. Translated into service discovery information, the MMT control message may include an information table for service discovery.

The server dividing the multimedia content into a plurality of segments allocates URL information to a plurality of segments divided into a predetermined number, and stores URL information about each segment in a media information file and transmits the URL information to the client.

The media information file may be called various names such as "media presentation description (MPD)" or "manifest file" according to a standardization organization that standardizes HTTP streaming. Hereinafter, the media information file is referred to and described as a media presentation description (MPD).

The cross-layer interface is described below.

The Cross Layer Interface (CLI) provides a means for supporting QoS in a single entity by exchanging QoS related information between lower layers including the application layer and the MAC / PHY layer. The lower layer provides bottom-up QoS information such as network channel state, while the application layer provides information related to media characteristics as top-down QoS information.

The cross layer interface provides an integrated interface between the application layer and various network layers including IEE802.11 WiFi, IEEE 802.16 WiMAX, 3G, 4G LTE, etc. Common network parameters of popular network standards are extracted as NAM parameters for static and dynamic QoS control of real-time media applications over various networks. The NAM parameter may include a BER value that is a bit error rate. BER can be measured at the PHY or MAC layer. The NAM also provides the identification of the underlying network, possible bit rates, buffer conditions, peak bit rates, service unit sizes, and service data unit loss rates.

Two different methods can be used to provide the NAM. The first way is to provide an absolute value. And the second is to provide relative values. The second method can be used to update the NAM while connected.

The application layer provides top-down QoS information related to media characteristics for lower layers. There are two types of top-down information such as MMT asset level information and packet level information. MMT asset information is used for capacity exchange and / or resource (re) allocation at lower layers. Packet level top down information is recorded in the appropriate field of every packet for the lower layer to identify the QoS level it supports.

The lower layer provides bottom-up QoS information to the application layer. The lower layer provides information regarding network conditions that change over time, enabling faster and more accurate QoS control at the application layer. Bottom-up information is expressed in an abstracted form to support heterogeneous network environments. These parameters are measured at the lower layer and read at the application layer periodically or at the request of the MMT application.

Hereinafter, in a system for transmitting encoded media data through a heterogeneous IP network (hereinafter referred to as MMT system), information that can be provided by the media encoder in relation to the media data is indicated. Explain the directive.

4 is a flowchart illustrating a method of transmitting coded media fragment data through a heterogeneous IP network according to an embodiment of the present invention. A method for transmitting coded media fragment data through a heterogeneous IP network according to an embodiment of the present invention may be performed as shown in FIG. 4. In the method for transmitting encoded media fragment data according to an embodiment of the present invention, a media unit (MU) having a format independent of a specific media codec is provided from a media codec layer (S610). The provided media unit is encapsulated to generate an MMT asset (S620). As described above, the MMT package is encapsulated to generate an MMT package (S630), the MMT package is received to generate an MMT payload format (S640), and the MMT payload format is received to MMT. A transport packet (MMT Transport Packet) is generated (S650).

An MMT asset according to an embodiment of the present invention is configured as a bundle of media units, and is a unit having the same MMT Composition Information (MMT CI) and MMT Transport Characteristics (MMT TC). The MMT asset according to another embodiment of the present invention may have only one of MMT composition information or MMT transmission characteristics.

Structure and relationship of MMT asset, MMT composition information and MMT transmission characteristics according to an embodiment of the present invention will be described. The MMT composition information and the MMT transmission characteristic have a separate format from the MMT asset, and are packaged together with one or more MMT assets at the MMT package level. The MMT composition information has a unique index, and the MMT asset is related to the MMT composition information referenced by the asset through this index. Similarly, the MMT transmission characteristic has a unique index and the MMT asset is related to the MMT transmission characteristic referenced by the corresponding MMT asset through this index.

Table 1 shows syntax of an MMT asset according to an embodiment of the present invention.

Table 1

asset_index is an index that distinguishes an MMT asset from other MMT assets and is a unique indicator. Different MMT assets have different asset_index. asset_index is used as a basic factor for describing interrelationships between MMT assets or describing interdependencies in MMT composition information.

comp_info_index is an index that distinguishes two or more MMT composition information from each other and is a unique indicator. Different MMT composition information has different comp_info_index. Using this indicator, the MMT asset indicates MMT composition information referenced by the MMT asset.

tx_char_index is an index that distinguishes two or more MMT transmission characteristics from each other and is a unique indicator. Different MMT transmission characteristics have different tx_char_index. Using this indicator, the MMT asset indicates the MMT transmission characteristic that it refers to.

no_of_unit represents the number of media units included in the MMT asset.

Table 2 shows syntax of MMT composition information according to an embodiment of the present invention.

TABLE 2

comp_info_index is an index that distinguishes two or more MMT composition information from each other. It is a unique indicator. Different MMT composition information has different comp_info_index. Using this indicator, the MMT asset indicates MMT composition information referenced by the MMT asset.

comp_data () is a composition information data unit included in the MMT composition information. The composition information data unit includes information on at least one of temporal and spatial relationships between MMT assets.

Table 3 is a syntax of MMT transmission characteristics according to an embodiment of the present invention.

TABLE 3

tx_char_data () is a data portion of the MMT transmission characteristic. The transmission characteristic data unit includes information related to transmission of the MMT asset.

Referring to FIG. 4 again, a process in which MMT asset, MMT composition information, and MMT transmission characteristics are packaged into an MMT package according to an embodiment of the present invention will be described. The MMT asset according to another embodiment of the present invention may be packaged in an MMT package together with MMT composition information or MMT transmission characteristics.

According to an embodiment of the present invention, the MMT program provider encapsulates the provided media unit to generate an MMT asset (S620). And their transmission characteristics.

The MMT program provider inserts at least one of temporal and spatial relationships between MMT assets into the MMT composition information. It can be inserted into the data portion of the MMT composition information. The MMT program provider inserts an index of the MMT composition information into a header portion of the MMT composition information and inserts the same index into the MMT composition information index of the MMT asset.

In the same way, the MMT program provider inserts the transmission characteristics of the MMT asset into the MMT transmission characteristics. It may be inserted into the data portion of the MMT transmission characteristic. The MMT program provider inserts an index of the MMT transmission characteristic into the header of the MMT transmission characteristic and inserts the same index as the MMT transmission characteristic index of the MMT asset.

In operation S630, the MMT program provider encapsulates the MMT asset and generates an MMT package by encapsulating the generated MMT asset, MMT composition information, and MMT transmission characteristics. The transmission of the coded media fragment data is continued.

As described above, the MMT program provider receives the MMT package and generates an MMT payload format (S640), and receives an MMT payload format to generate an MMT Transport Packet (S650).

Claims

In the method for transmitting encoded media data in a system for transmitting coded media fragment data through a heterogeneous IP network,

Receiving a media unit (MU) having a format independent of a specific media codec from a media codec layer;

Encapsulating the generated media unit to generate an MMT asset;

Generating an MMT package by encapsulating the generated MMT asset;

Receiving the generated MMT package and generating an MMT payload format; And

Receiving the generated MMT payload format and generating an MMT transport packet;

The MMT asset stores an MMT asset indicator which is an index for distinguishing the MMT asset from other MMT assets and an index of MMT Composition Information (MMT CI) referenced by the MMT asset. And a composition information indicator.
The method of claim 1,

Generating an MMT asset by encapsulating the generated media unit further includes generating MMT composition information representing information on at least one of temporal and spatial relationships between the MMT assets. and,

The generating of the MMT package by encapsulating the generated MMT asset may include generating the MMT package by encapsulating the generated MMT asset and the MMT composition information. Data transfer method.
The method of claim 2,

The MMT composition information includes the MMT composition information indicator, which is an index for distinguishing the MMT composition information from other MMT composition information and information on at least one of temporal and spatial relationships between the MMT assets,

And the MMT asset and the MMT composition information maintain relevance as the MMT composition information indicator.
The method of claim 2,

The MMT composition information includes a composition information header part and a composition information data part, wherein the composition information data part includes information on at least one of temporal and spatial relationships between the MMT assets, and the composition information header part includes the MMT composition information Including the MMT composition information indicator which is an index to distinguish it from other MMT composition information,

And the MMT asset and the MMT composition information maintain relevance as the MMT composition information indicator.
The method of claim 1,

The MMT asset further includes an indicator indicating the number of the media units stored in the MMT asset.
The method of claim 1,

The MMT asset includes a header portion and a data portion, the data portion includes the media unit, and the header portion refers to an MMT asset indicator and the MMT asset that are indexes for distinguishing the MMT asset from other MMT assets. And a MMT composition information indicator for storing an index of MMT composition information.
The method of claim 1,

The MMR asset further comprises an MMT transport characteristic indicator for storing an index of the MMT transport characteristics (MMT TC) referenced by the MMT asset.
The method of claim 2,

The generating of the MMT asset by encapsulating the generated media unit further includes generating an MMT transport characteristic (MMT TC) indicating information related to the transmission of the MMT asset.

The generating of the MMT package by encapsulating the generated MMT asset and the MMT composition information may include generating the MMT package by encapsulating the generated MMT asset, the MMT composition information, and the MMT transmission characteristics. And transmitting the encoded media data.
The method of claim 7, wherein

The MMT asset further includes an indicator indicating the number of the media units stored in the MMT asset.
The method of claim 7, wherein

The MMT asset includes a header portion and a data portion, the data portion includes the media unit, and the header portion refers to an MMT asset indicator which is an index for distinguishing the MMT asset from other MMT assets. And an MMT composition information indicator storing an index of MMT composition information and an MMT transmission characteristic indicator storing an index of an MMT transmission characteristic referred to by the MMT asset.
In the method for transmitting encoded media data in a system for transmitting coded media fragment data through a heterogeneous IP network,

Receiving a media unit (MU) having a format independent of a specific media codec from a media codec layer;

Encapsulating the generated media unit to generate an MMT asset;

Generating an MMT package by encapsulating the generated MMT asset;

Receiving the generated MMT package and generating an MMT payload format; And

Receiving the generated MMT payload format and generating an MMT transport packet;

The MMT asset stores an MMT asset indicator, which is an index for distinguishing the MMT asset from other MMT assets, and an index of an MMT Transport Characteristics (MMT TC) referenced by the MMT asset. And a transmission characteristic indicator.
The method of claim 11,

The generating of the MMT asset by encapsulating the generated media unit further includes generating an MMT transport characteristic (MMT TC) indicating information related to the transmission of the MMT asset.

The generating of the MMT package by encapsulating the generated MMT asset may include generating the MMT package by encapsulating the generated MMT asset and the MMT transmission characteristic. Data transfer method.
The method of claim 12,

The MMT transmission characteristic includes information related to the transmission of the MMT asset and the MMT transmission characteristic indicator which is an index for distinguishing the MMT transmission characteristic from another MMT transmission characteristic,

And the MMT asset and the MMT transmission characteristic maintain relevance as the MMT transmission characteristic indicator.
The method of claim 12,

The MMT transmission characteristic information includes a transmission characteristic header unit and a transmission characteristic data unit, the transmission characteristic data unit includes information related to the transmission of the MMT asset, and the transmission characteristic header unit is different from the MMT transmission characteristic other MMT transmission characteristics. Including the MMT transmission characteristic indicator that is an index to distinguish,

And the MMT asset and the MMT transmission characteristic maintain relevance as the MMT transmission characteristic indicator.
The method of claim 11,

The MMT asset further includes an indicator indicating the number of the media units stored in the MMT asset.