KR101829064B1 - Method and apparatus for deliverying dash media file over mmt delivery system - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system, and more particularly, to a DASH (Dynamic Adaptive Streaming over HTTP) standard media data and an MMT (MPEG Media Transport) A method of interworking between standardized media data and an MMT transmission system includes the steps of analyzing media data of an MPEG DASH standard, replacing the media data with an MPEG MMT transmission standard, And generating a container and an identifier of the container.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and an apparatus for interworking media data of a DASH standard with an MMT transmission system,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system, and more particularly, to a method and apparatus for interworking media data of a dynamic adaptive streaming over HTTP (DASH) standard with an MMT (MPEG Media Transport) transmission system.

Recently, the importance of smooth transmission of contents is increasing due to the increase of users who use online contents. Adaptive streaming technology in which the bit rate of content is smoothly changed according to the available transmission bandwidth or the performance of the user's device is becoming a hot topic. This adaptive streaming technology is a technology that analyzes the user's network environment and optimizes the bit rate. In this way, a unit of content divided into small pieces based on an HTTP (Hyper Text Transfer Protocol) protocol such as adaptive streaming is selected and played by a user terminal according to a situation, so that a user can use the content without delay or interruption Transmission technologies that allow for the use of the Internet are discussed in several standards bodies. One of the related standards is the DASH standard discussed in the MPEG standard. MPEG DASH can achieve AV streaming dynamically adaptive to network environment and terminal environment in wired / wireless Internet according to trend of AV streaming using HTTP / TCP instead of AV streaming using RTP / UDP, which is blocked by internet firewall. .

In the IP-based convergence era, convergence of communication and broadcasting is attracting attention as one of next-generation market leading technologies as a next-generation new business model with high marketability. In particular, IPTV (Internet Protocol Television), which is the biggest axis of Convergence of Broadcasting and Mobile Service (CBMS), not only provides services that recombine or combine existing TV, voice and data technologies, but also supports bi- It is a technology that can create models and services. Particularly, the IPTV technology is not limited to providing a specialized service in a limited terminal environment, but may be applied to a fixed terminal such as a set-top box, a PC, and a TV, a mobile terminal such as a mobile phone, a PDA (Personal Digital Assistants), a wired and wireless network, By providing services regardless of the network, the same service can be provided and applied in various environments, and various types of services can be discovered by considering various environments.

With the explosive growth of wired and wireless Internet, various forms of Internet TV will be a meaningful part of our lives in the future. AV transmission through wired and wireless Internet can not replace existing broadcasting, but it will develop into hybrid service combining broadcasting network and internet. In addition, unlike the past, which used private networks for content delivery between studios and delivering content to secondary distribution networks, it recently delivered this through the IP network, thereby reducing the cost of dedicated networks and reducing the cost of expensive equipment due to specialized interfaces. The tendency to do so is getting stronger. In addition, specifications for a multimedia transmission system considering a plurality of network environments mounted on a DTV and a mobile terminal are also discussed in the MPEG standard specification. To this end, the MPEG standards are divided into a file standard for hybrid contents for hybrid services, a transmission standard for hybrid networks, and a control standard for providing broadcasting and communication services.

The present invention provides a method and apparatus for interworking with DASH standard media data and an MMT transmission system.

The present invention also provides a method and apparatus for composing and generating multimedia contents including DASH standard media in a multimedia broadcasting system of the MMT standard.

In addition, the present invention provides a method and apparatus for generating multimedia contents in a multi-media broadcasting system of the MMT standard in consideration of characteristics of various media constituting multimedia contents including DASH standard media.

The present invention also provides a method and an apparatus for transmitting multimedia contents of the MMT standard in the DASH transmission standard in the multimedia broadcasting system of the MMT standard.

A method of interworking between heterogeneous systems for providing multimedia services according to the present invention includes the steps of analyzing multimedia presentation description (MPD) information of a dynamic adaptive streaming over HTTP (DASH) system, media transport system encapsulation information, and generating a container and an identifier of the MMT system using the substituted encapsulation information,
The replacing process may include a step of generating composition information (CI) indicating a relationship between time and space of the MMT package based on time information of a period included in the MPD information and adaptive group information of an adaptation set, (MMT) encapsulation layer (MMT E layer) based on information on the use of hypertext transfer protocol (HTTP) in the DASH system, To the loss rate and delay time of the transport characteristics (TC) of the transport stream.

1 is a diagram showing a structure of a media file defined by MPEG DASH,
FIG. 2 is a diagram showing a structure of a composite media content and a composite transmission system in the MPG MMT; FIG.
3 illustrates an interlocking structure of a DASH and an MMT according to an embodiment of the present invention,
4 is a structural diagram of a DASH media file;

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. Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

First, before describing the present invention, terms used in this specification will be defined.

- DASH: dynamically-variable HTTP-based streaming

- Content: Creation of movies, music, news, etc

- Content component: The component that constitutes the content; (Eg video, audio, subtitles)

- Representation: It is possible to present low-quality, high-quality representations in the form of representing contents.

The DASH includes representations that encode the same content components that constitute the same content under different conditions (network bandwidth, resolution, codec, etc.) and the entire content length The period is divided into a plurality of equal periods and the period is divided into a group capable of adaptive combination indicating information capable of satisfying various conditions of language, representation, and subtitles. In addition, MPD (Multimedia Presentation Description) (serving as a manifest file) specifying the file name, sequence number, start time, length, etc. of each segment (segmentation) . The attributes of the group that can be adaptively combined can be composed only of the same media type or attribute, and combinations or selections according to conditions can be possible within the group.

And the segment consists of an initialization segment having information for a decoder configuration so as to be able to properly decode the representation and media segments comprising the segmented content components.

The terminal requests and receives an MPD, determines which representation is present, determines the performance, the capability, and the network speed of the client device, selects a suitable presentation, and sequentially arranges the fragments in order Download and start playback.

If variable variables such as network bandwidth change, that is, as the network speed increases, fragments of representations created with higher bandwidths are picked up and reproduced, resulting in a change in picture quality depending on the speed of the network, It is possible to obtain a continuous effect without breaking. Also, by selecting the user or the client terminal, the change of the combination of the available language and the media segment can be reproduced by selecting from the attribute information of the possible group of the above-mentioned adaptive combination.

In order to receive the broadcast content service, the terminal receives the MPD data describing the content from the server and requests the corresponding presentation of the content based on the received MPD data.

In addition, the embodiments of the present invention will be described below by way of example of the MPEG MMT technique, which is one of the techniques to which the present invention can be applied, but the description does not limit the contents of the present invention.

FIG. 1 shows a structure of a media file defined by MPEG DASH.

Referring to FIG. 1, in the structure diagram, representations obtained by encoding the same content components constituting the same content under different conditions (network bandwidth, resolution, codec, etc.) and entire contents The length is divided into a plurality of equally divided periods, and the period is divided into segments of a sufficiently short time (for example, about 1 second to 10 seconds) together with information capable of satisfying various conditions (segmentation), and the file name, , MPD (Manifest file role) specifying start time, length, and the like.

4 shows the structure of MPD defined in DASH.

Referring to FIG. 4, it is assumed that a period is divided into periods in the MPD file, language identifiers of subtitles and voice signals, identifiers of media signals, roles of representations, preferences and commonly used attributes, (Adaptation Set, Bitrate) and other conditions (network bandwidth, network bandwidth, etc.) that are grouped together by the same conditions such as length, length, length, diagonal length, number of frames, number of channels, signal sampling period, bandwidth, resolution, codec, and the like, and a segment that is divided into time and space conditions according to a reproduction condition and a transmission environment, And sub-segments separated for specific functions such as playback. To this end, a plurality of Periods, Adaptation Sets, Representations, Segments, and Sub-segments may exist in a single MPD.

The operation of the DASH terminal receives the MPD from the server, analyzes the configuration of the period and the corresponding presentation step, requests data to the server using the HTTP protocol, receives the presentation data corresponding to the corresponding terminal Decoded by segment and reproduced.

FIG. 2 shows a structure of a system for processing multimedia contents in an MPEG MMT.

Referring to FIG. 2, in the system structure for transmitting the multimedia contents in the mixed network environment in the MPEG MMT, each area is defined as shown in Table 1 below.

domain Justice Encapsulation functional area (E) defines the format for the encapsulation of encoded media data either to be stored on some storage device or to the payload of delivery protocols and networks Delivery functional area (D) provides formats and functionalities that are required for transferring encapsulated media data from one network entity to another Control functional area (C) providing functionalities to control delivery and consumption of the media

The above-mentioned Encapsulation function area (E) performs media container format, media structure, media segmentation, media synchronization, and media protection functions. The delivery function area (D) And performs a function of considering data packetization and quality of transmission data to be adjusted to a transmittable size in consideration of a transmission environment. The control function area (C) is responsible for service discovery for the initial service discovery and control of advertisement, service transmission environment and complex media. And performs a function of transmitting and receiving a control signal for arbitrary reproduction and double speed reproduction, depending on the case.

Encapsulation consists of Media Fragment Unit, M-Unit, MMT Asset and MMT Package.

The media fragment unit is a general storage format in which the media data included in the MFU can be used independently of a specific media codec. The media fragment unit includes a codec type information, a priority of the encoded data, reference information of the corresponding media data, Information, and the start, middle, and last identifiers of the MFUs in group form, and includes a number identifier for identification of the group MFUs.

The M-Unit may include a single or a plurality of AUs as the abstraction processing units, and the MFU may be composed of a single or a plurality of MFUs. In this case, in order to represent the M-Unit to be processed at the same time, time information regarding playback and points for double speed playback and random playback are managed.

The Asset is composed of a single or a plurality of M-Units, and single or various types of media may exist. The Asset has various metadata such as media data identifier information capable of identifying the multimedia contents, size information of the data, and an identifier indicating whether to include setting information for setting the media codec.

The MMT Package may include a plurality of MMT Assets, and further includes information (CI) indicating a relationship between time and space and information (TC) considering a transmission environment.

The MMT Asset is a component of the MMT Package and may include audio, video and program information. Examples of the MMT Asset include an MPEG-2 TS stream, a PES packet, an MP4 file format, an MPEG-U widget data, . ≪ / RTI >

FIG. 3 illustrates an interlocking structure between a DASH and an MMT according to an embodiment of the present invention.

Referring to FIG. 3, the MPS data portion of the DASH standard must be able to be re-standardized as control information that can provide the MMT service and the corresponding media to the terminal. The information includes the location of the media, It should be able to provide the adaptable structure that can be provided according to the type of media and the type of media, in accordance with the structure of MMT. It may also be provided using the media-type / dash identifier, which is a DASH file specification, as the case may be.

More specifically, it is a process of converting DASH specification data into MMT encapsulation data. To this end, the time information of the Period existing in the DASH MPD information and the adaptive group configuration information of the Adaptation Set are converted into the information (CI) indicating the relationship between time and space in the MMT Package and the information (TC) considering the transmission environment. Asset includes various metadata such as media data identifier information capable of identifying multimedia contents, size information of data, an identifier indicating whether setting information for setting a media codec is included, . The size information of the DASH segment and the address information of the next segment can be converted into the stream ID information of the Asset and the time configuration information of the M-Unit.

In addition, the information to be provided to the MMT D layer is the byte range information of the DASH media data transmission described in the MPD is the size of the MMT transmission data, and the bit rate of the media provided in the presentation is the MMT May be replaced with an average bit rate among the network transmission parameters. In addition, the information on the use of the HTTP protocol provided in the DASH standard can be converted into the loss rate and the delay time of the transport characteristics provided by the MMT E layer. The configuration information of each segment of DASH is provided in a similar manner to real-time broadcasting, and it must be provided as continuous packet information using a sequence number or the like for MMT transmission packet configuration.

As for the interworking method between the MPEG DASH standard and the MPEG MMT standard, it means that the MMT standard data can be replaced with the DASH standard.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but is capable of various modifications within the scope of the invention. Therefore, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

Claims (2)

A method of interworking between heterogeneous systems for providing multimedia services,
Analyzing information of a multimedia presentation description (MPD) of a dynamic adaptive streaming over HTTP (DASH) system,
Replacing the MPD information with encapsulation information of an MPEG media transport (MMT) system;
And generating a container and an identifier of the MMT system using the substituted encapsulation information,
In the replacing step,
Based on the time information of the period included in the MPD information and the adaptive group information of the adaptation set, considering the composition information (CI) indicating the relationship on the time and space of the MMT package and the transmission environment Into transport characteristics (TC)
A process of converting the loss rate and the delay time of the transport characteristics (TC) of the MMT encapsulation layer (MMT E layer) to the delay time based on the information on use of hypertext transfer protocol (HTTP) in the DASH system The method comprising the steps of:

The method according to claim 1,
Analyzing media data of the DASH system and replacing it with media data of the MMT system;
Further comprising the step of transmitting media data of the substituted MMT system using an MMT protocol (MMT protocol)
The process of replacing media data in the MMT system comprises:
To a media fragment unit (MFU) of the MMT system based on a segment of the DASH system.

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