WO2017039021A1

WO2017039021A1 - Content transmission method supporting scalable encoding and streaming server therefor

Info

Publication number: WO2017039021A1
Application number: PCT/KR2015/009091
Authority: WO
Inventors: 박우출; 이윤주
Original assignee: 전자부품연구원
Priority date: 2015-08-28
Filing date: 2015-08-28
Publication date: 2017-03-09
Also published as: KR20170026809A

Abstract

The present invention relates to a content transmission method and, more particularly, to a content transmission method supporting scalable encoding, and a streaming server for the same, wherein, when a content is encoded using a scalable encoding method, a bit stream of each layer is divided into at least a certain number of substreams, each substream is assigned an index, and then metadata for the index is defined, so that a terminal can easily receive and use the content by making reference to the indexes of the substreams even when each substream is located at a different storage location.

Description

Content delivery method supporting scalable encoding and streaming server for same

The present invention relates to a content transmission method, and more particularly, when encoding content in a scalable encoding method, by dividing a bitstream of each layer into a predetermined number or more of substreams and assigning an index to each substream. The present invention relates to a content transmission method that supports scalable encoding that can be used for content transmission by defining metadata for the content transmission, and a streaming server therefor.

The contents described in this section merely provide background information on the present embodiment and do not constitute a prior art.

In order to stream UHD (Ultra High Definition) broadcast contents, which are in the spotlight recently, a large network bandwidth and a large storage space are required.

However, there is a problem that a single transmission through a single channel between the terminal and the server does not use the network bandwidth efficiently.

On the other hand, various encoding techniques are applied to solve the problem of requiring a large storage space. Currently, the most widely used encoding scheme is Scalable High Efficiency Video Coding (SHVC), which is one of scalable encoding techniques.

SHVC codes content into multiple layers of base layer (BL) and enhancement layer (EL) to reduce data size and separate bitstreams to adaptively receive and play content according to user network bandwidth. Refers to a coding scheme that supports it. In this case, the terminal receives and decodes the base layer and the enhancement layer together to restore the resolution of the original content.

However, the scalable encoding method up to now has a problem in that it is impossible to efficiently use the storage space by storing data for each bitstream, and multiple transmissions are impossible because any one server concentrates and stores the bitstream.

The present invention has been proposed to solve the above-described problems. In particular, when encoding content using a scalable encoding method, after dividing a bitstream of each layer into a predetermined number or more of substreams, an index for each substream is assigned. It is an object of the present invention to provide a content transmission method for supporting scalable encoding that can be used for content transmission by defining metadata for the index and a streaming server for the same.

In other words, by dividing the bitstreams of each layer into more than a certain number of substreams, assigning indexes for each substream, and defining metadata for the indexes, even if each substream is located in a different storage location, the substreams It is an object of the present invention to provide a method for transmitting a content and a streaming server for supporting the scalable encoding that a terminal can easily receive and use the content with reference to the index.

However, the object of the present invention is not limited to the above object, and other objects not mentioned will be clearly understood from the following description.

According to an embodiment of the present invention, a content transmission method supporting scalable encoding includes a bitstream of a base layer and an enhancement layer layered in any one content. Generating by dividing a predetermined number or more of substreams; Assigning and storing an index corresponding to each of the generated substreams; And generating the metadata for the index and transmitting the metadata to the terminal requesting the content, and transmitting the substream of the content to the terminal according to the request of the terminal.

In this case, the dividing step may include generating bits of each layer in consideration of at least one of state information of a network, performance information of a terminal requesting the content, and performance information of a storage location capable of storing the substream. The stream may be generated by dividing the stream into a predetermined number or more of substreams.

In this case, the index may include at least one of identification information for identifying the substream, fragment identification information including the substream, and identification information on a storage location where the substream is stored.

In addition, the metadata may include a plurality of metadata generated corresponding to the performance information of the terminal or limiting elements that can be received in consideration of the performance of the terminal.

In addition, after the transmitting, if the substream of the content is cached in any one cache device distributed in the vicinity of the terminal, receiving the caching information from the cache device; And modifying the metadata according to the received caching information.

In addition, the present invention can provide a computer readable recording medium having recorded thereon a program for executing a content transmission method supporting scalable encoding as described above.

A streaming server according to an embodiment of the present invention for achieving the above object is a layering to generate a bitstream for each layer by layering any content into a base layer and an enhancement layer part; A substream generator for dividing the bitstreams of the layered layers into a predetermined number or more of substreams; And an index management unit for assigning an index corresponding to each of the generated substreams.

In this case, the streaming server generates metadata corresponding to the index, and the substream of the content is cached in any one cache device in which the substream delivered to the requesting terminal is distributed in the vicinity of the terminal. In this case, the MPD generation module may be further configured to receive the caching information from the cache device and to modify the metadata according to the received caching information.

According to a content transmission method and a streaming server for supporting the scalable encoding of the present invention, when encoding a content using the scalable encoding method, the bitstream of each layer is divided into a predetermined number of substreams and an index for each substream. After defining the metadata for the index, even if each substream is located in a different storage location, the terminal can easily receive and use the content with reference to the index for the substream.

In addition, by dividing the bitstream of each layer into a predetermined number or more of substreams and storing them in different storage locations, the storage space can be utilized more efficiently, and the terminal can be connected through a plurality of channels, thereby enabling multiple transmission. This allows for more efficient use of network traffic.

In addition, high-capacity content can be partitioned and cached, thereby enabling application of a CDN (Contents Delivery Network) service that is difficult to support high-capacity caching.

In addition, various effects other than the above-described effects may be directly or implicitly disclosed in the detailed description according to the embodiment of the present invention to be described later.

1 is a block diagram showing a content delivery system according to an embodiment of the present invention.

2 is a block diagram showing a main configuration of a terminal according to an embodiment of the present invention.

3 is a block diagram showing the main configuration of a streaming server according to an embodiment of the present invention.

4 is a block diagram illustrating a main configuration of an encoding module according to an embodiment of the present invention.

5 is a flowchart illustrating a content transmission method according to an embodiment of the present invention.

6 to 8 are exemplary diagrams for describing a content transmission method according to an embodiment of the present invention.

9 is a flowchart illustrating a content reproduction method in a terminal according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS To make the features and advantages of the present invention more clear, the present invention will be described in more detail with reference to specific embodiments shown in the accompanying drawings.

However, in the following description and the accompanying drawings, detailed descriptions of well-known functions or configurations that may obscure the subject matter of the present invention will be omitted. In addition, it should be noted that like elements are denoted by the same reference numerals as much as possible throughout the drawings.

The terms or words used in the following description and drawings should not be construed as being limited to the ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms for explaining their own invention in the best way. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention. Therefore, the embodiments described in the present specification and the configuration shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all of the technical ideas of the present invention, and various alternatives may be substituted at the time of the present application. It should be understood that there may be equivalents and variations.

In addition, terms including ordinal numbers, such as first and second, are used to describe various components, and are used only to distinguish one component from another component, and to limit the components. Not used. For example, without departing from the scope of the present invention, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component.

In addition, when a component is referred to as being "connected" or "connected" to another component, it means that it may be connected or connected logically or physically. In other words, although a component may be directly connected or connected to other components, it should be understood that other components may exist in the middle, and may be connected or connected indirectly.

In addition, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In addition, the terms "include" or "having" described herein 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 of them. It is to be understood that it does not exclude in advance the possibility of the presence or addition of other features or numbers, steps, operations, components, components or combinations thereof.

In addition, embodiments within the scope of the present invention include computer readable media having or conveying computer executable instructions or data structures stored on the computer readable medium. Such computer readable media can be any available media that can be accessed by a general purpose or special purpose computer system. By way of example, such computer readable media may be in the form of RAM, ROM, EPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage, or computer executable instructions, computer readable instructions or data structures. And may include, but are not limited to, any other medium that can be used to store or deliver certain program code means, and can be accessed by a general purpose or special purpose computer system. .

In the following description and claims, “network” is defined as one or more data links that enable the transfer of electronic data between computer systems and / or modules. When information is transmitted or provided to a computer system via a network or other (wired, wireless, or a combination of wired or wireless) communication connections, this connection can be understood as a computer-readable medium. Computer-readable instructions include, for example, instructions and data that cause a general purpose or special purpose computer system to perform a particular function or group of functions. The computer executable instructions may be, for example, binary, intermediate format instructions such as assembly language, or even source code.

In addition, the present invention relates to personal computers, laptop computers, handheld devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, mobile phones, PDAs, pagers It may be practiced in a network computing environment having various types of computer system configurations, including (pager) and the like.

In addition, the terminal described in the specification of the present invention may be implemented in various forms. For example, mobile terminals such as smart phones, tablet PCs, personal digital assistants, portable multimedia players, and MP3 players, as well as smart TVs and desktop computers. A fixed terminal may be used, and any terminal can be used as a terminal of the present invention as long as the terminal can be used by uploading or downloading content to a content server through a network.

In addition, any content described in the specification of the present invention may be included in the content of the present invention as long as it can be expressed by a specific address (eg, a URL) on the network. For example, when the entire web site is represented by one URL, it can be distributed through the system of the present invention as one content.

The invention may also be practiced in distributed system environments where both local and remote computer systems that are linked via wired networks, wireless data links, or combinations of wired and wireless data links perform tasks. In a distributed system environment, program modules may be located in both local and remote memory storage devices.

Now, a content transmission method and a streaming server for supporting scalable encoding according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, a content delivery system supporting a content delivery method supporting scalable encoding according to an embodiment of the present invention will be described.

Referring to FIG. 1, a content delivery system according to an exemplary embodiment of the present invention may include a terminal 100 and a streaming server 200.

First, the terminal 100 refers to a device that requests specific content to the streaming server 200 through the network 300 according to a user's request, and receives and uses the content provided from the streaming server 200. More specifically, the terminal 100 of the present invention confirms a request for specific content from the user. The request for the specific content may include an execution process of a browser, a playback application, etc. that may receive and use the content provided by the streaming server 200. Thereafter, the terminal 100 receives metadata about the content from the streaming server 200, checks the location of the storage location holding the content based on the metadata, requests the content from the storage location, and receives the content. You can do it.

At this time, when the location of the storage location that holds the identified content based on the metadata is identified in the form of a URL, the terminal 100 accesses a name server such as a domain name server (DNS) and provides the corresponding content. It obtains the address information (IP address) of the storage location, and requests the storage location to use the content.

In addition, the terminal 100 according to an embodiment of the present invention may receive the content on a sub-stream basis from a storage location that stores the corresponding content, for example, the streaming server 200. In this case, the terminal 100 according to the present invention may request and receive content in units of fragments, which are sets of a plurality of substreams, after checking metadata, and may decode the received substreams and play them in units of fragments. .

The streaming server 200 is to provide various contents such as photographs, videos, audio, applications, etc. to the terminal 100, or to receive and provide contents related services. The content provider (CP; Contents) At least one content is provided from the provider and managed, and serves to provide content to the plurality of terminals 100 through the network 300. In this case, the streaming server 200 of the present invention supports scalable encoding of content, and supports a process of dividing a layered bitstream into substreams and storing the divided substreams. In addition, the streaming server 200 of the present invention may support the process of assigning an index for each substream and defining metadata for the index and then distributing it to the terminal 100.

In addition, a plurality of streaming servers 200 of the present invention may exist. When there is a plurality, any one streaming server 200 performs scalable encoding of content, and the other server may play a role of a database server.

The main configuration and operation of the terminal 100 and the streaming server 200 according to an embodiment of the present invention will be described later, the present invention can be applied to the CDN service. That is, as shown in FIG. 1, the network 300 of the present invention may include a plurality of cache devices 350 distributed in a distributed manner. At this time, the plurality of cache devices 350 is preferably located between the access network 330 and the core network 320, but is not fixed to the location, the packet transmitted and received between the terminal 100 and the streaming server 200 If you can monitor and control the flow of content, it can be distributed in various forms.

The cache apparatus 350 applied to the CDN service up to now has a problem that it is difficult to store high-capacity content because of a small storage space. The present invention is to solve this problem, the streaming server 200 may support the process of dividing the content into a plurality of substreams in the encoding process is stored in the distributed cache device 350, a plurality of cache devices Each 350 may be connected to the terminal 100 through a separate channel to simultaneously transmit a corresponding substream to the terminal 100 according to a request of the terminal 100.

In addition, the cache apparatus 350 of the present invention may monitor and detect a substream transmitted from the streaming server 200 to the terminal 100, and store the detected substream, and may transmit information about this to the streaming server 200. By transmitting to the streaming server 200 may support the process of changing the metadata is made.

In addition, the network 300 in which the plurality of cache devices 350 of the present invention are distributed and distributed at a main point means a communication network for transmitting and receiving information between the terminal 100 and the streaming server 200, and in particular, a single network. Rather than a communication network type, a communication network implemented using various types of wired and wireless communication technologies such as an intranet network, a mobile communication network, and a satellite communication network may be mixed.

Here, the network 300 may be configured to include an external network, for example, an internet network 310 connected to a mobile network including a plurality of wired / wireless access networks 330 and a core network 320. Here, the wired / wireless access network 330 constituting the mobile network is an access network performing wired / wireless communication with the terminal 100. For example, a plurality of base stations (BS), a base transceiver station (BTS), NodeB, eNodeB, etc. The base station may be implemented as a base station controller such as a base station controller (BSC) and a radio network controller (RNC).

As another method, a digital signal processor and a wireless signal processor, which are integrally implemented in the base station, are divided into digital units (hereinafter referred to as DUs and radio units (hereinafter referred to as RUs)). Each of the plurality of RUs (not shown) may be installed in the region of the plurality, and the plurality of RUs (not shown) may be configured by connecting with a centralized DU (not shown).

In addition, the core network 320 constituting the mobile network together with the wired / wireless access network 330 serves to connect the wired / wireless access network 330 with an external network, for example, the internet network 310.

As described above, the core network 320 is a network system that performs a main function for a mobile communication service such as mobility control and switching between wired and wireless access networks 330, and includes circuit switching or packet switching. It manages and controls packet flow in mobile network. In addition, the core network 320 may manage inter-frequency mobility and may play a role for interworking with traffic in the access network 330 and the core network 320 and other networks, such as the Internet network 310. In addition to the above-described configuration, the core network 320 may further include a mobile switching center (MSC), a home location register (HLR), a mobile mobility entity (MME), a home subscriber server (HSS), and the like.

In addition, the Internet network 310 refers to a conventional public communication network, that is, a public network, through which information is exchanged according to the TCP / IP protocol, and is connected to the streaming server 200 and provided from the streaming server 200. May be provided to the terminal 100 via the core network 320 and the wired / wireless access network 330, or may be provided to the plurality of cache devices 350 according to a predetermined distribution policy.

As described above, the structure of the network 300 of the present invention has been briefly described. The network 300 is coupled to the cache device 350 to store computing resources such as hardware and software, and corresponds to the computing resources required by the client. It may include a cloud computing network that can be provided to the terminal. Here, cloud computing refers to a computer environment in which information is permanently stored on a server on the Internet and temporarily stored in client terminals such as desktops, tablet computers, laptops, netbooks, and smartphones. It refers to a computer environment access network that stores a server on the Internet and makes this information available anytime, anywhere through various IT devices. The network 300 may include a closed network such as a local area network (LAN), a wide area network (WAN), an open network such as the Internet, and code division multiple access (CDMA) and wideband code division (WCDMA). The concept includes both networks such as multiple access (GSM), global system for mobile communications (GSM), long term evolution (LTE), and evolved packet core (EPC), as well as next-generation and cloud computing networks.

In addition, a processor mounted in each device according to an embodiment of the present invention may process a program command for executing a method according to the present invention. In one implementation, this processor may be a single-threaded processor, and in another implementation, the processor may be a multithreaded processor. Furthermore, the processor is capable of processing instructions stored on memory or storage devices.

Hereinafter, the configuration and operation method of the terminal 100 according to an embodiment of the present invention will be described with reference to FIG. 2.

1 and 2, the terminal 100 according to an embodiment of the present invention includes a communication unit 110, an input unit 120, a control unit 130, an output unit 140, and a storage unit 150. Can be configured.

In more detail with respect to each component, first, the communication unit 110 performs a role of transmitting and receiving information with the streaming server 200 through the network (300). To this end, the communication unit 110 of the present invention may perform a procedure of accessing the network 300. The communication unit 110 searches for a base station (not shown) located within a predetermined radius and requests a connection of the discovered base station (not shown). By supporting the process of accessing the base station (not shown), the access network 330 may be connected. Here, the process of connecting the communication unit 110 of the terminal 100 to the base station (not shown) of the access network 330 may employ a variety of well-known configuration, a detailed description thereof will be omitted. In addition, the communication unit 110 may transmit user information when performing a communication procedure with a base station (not shown). Basically, a terminal identification number, such as an International Mobile Subscriber Identity (IMSI), may be transmitted to a base station (not shown), and while the base station (not shown) performs an access procedure with the core network 320, the terminal identification number, etc. By using the subscriber information can be confirmed.

In addition, when the communication unit 110 according to an embodiment of the present invention normally connects to the core network 320 through a base station (not shown) of the access network 330, the communication unit 110 may request and receive content.

The input unit 120 transmits a variety of information such as numeric and text information input from a user, a signal input in connection with various function settings and function control of the terminal 100, to the controller 130. In particular, the input unit 120 of the present invention may support a user input necessary for accessing the streaming server 200.

As described above, the input unit 120 includes a key input means such as a keyboard or a keypad, a touch input means such as a touch sensor or a touch pad, a voice input means, a gyro sensor, a geomagnetic sensor, an acceleration sensor and a proximity sensor, and a camera. It may also include a gesture input means comprising at least one or more.

In addition, it may include all types of input means that are currently under development or may be developed in the future.

The controller 130 performs overall control of the terminal 100, and includes at least one processor including a central processing unit (CPU) and an execution memory (eg, a register and at least one memory loading data) loaded in hardware. And / or a random access memory (RAM) and a bus that inputs and outputs at least one data into the processor and memory. In addition, it may include a predetermined program routine (Routine) or program data that is loaded into the execution memory from a predetermined recording medium to be performed by the processor to perform a function defined in the terminal 100 by software. . In other words, among the functions provided in the terminal 100 to support the content transmission and reproduction processing of the present invention, a component that can be processed by software may be determined as the function of the controller 130.

As such, the controller 130 of the present invention is functionally connected to at least one component provided for content transmission and playback processing according to an embodiment of the present invention. That is, the controller 130 is functionally connected to the communication unit 110, the input unit 120, the storage unit 140, and the output unit 150, and controls the flow of signals for supplying power and performing functions to the components. Control.

In particular, the controller 130 according to an embodiment of the present invention may include a content reproduction processing module 131 and a decoding module 132.

The content reproduction processing module 131 controls overall contents related to content request, reception, and reproduction. For example, the content reproduction processing module 131 may execute a reproduction application. Here, the playback application performs a function of playing back the content provided by the streaming server 200. For example, it may be an application capable of playing high quality content provided by the streaming server 200. However, the present invention is not limited thereto, and any application (for example, a browser) may be a playback application of the present invention as long as the streaming server 200 can play content provided by the streaming server 200.

The content reproduction processing module 131 checks the MPD information, which is metadata. Through the MPD, the content reproduction processing module 131 of the present invention may check address information (URL) for each substream, and may request and receive a substream from a corresponding device. In this case, the content reproduction processing module 131 of the present invention may check the sub-index information for each sub-stream, and simultaneously request and receive the sub-stream when the sub-index information is the same. In addition, the substreams of the present invention may be stored in different places, for example, the substreams may be stored in a cache device 350 distributed in the vicinity of the terminal 100 and the streaming server 200 or the streaming server 200 ) Can be distributed and stored in a database server that can interoperate with.

The content reproduction processing module 131 of the present invention may simultaneously request and simultaneously receive content for each substream having the same subindex, and transmit the received substream to the decoding module 132 to request decoding.

The decoding module 132 of the present invention decodes a substream delivered from the content reproduction processing module 131 and transmits the result thereof to the content reproduction processing module 131 to support the reproduction of the content.

The storage 140 may temporarily store various data generated during execution of the application program, including an application program required for operating a function according to an embodiment of the present invention. In particular, the storage 140 according to an embodiment of the present invention can store and manage information related to the playback application 151 that can execute the content provided by the streaming server 200, and store the received substream. And manage.

The storage 140 may largely include a program area and a data area. The program area stores related information for driving the terminal 100 such as an operating system (OS) for booting the terminal 100. The data area is an area in which data generated according to the use of the terminal 100 is stored, and as described above, a substream delivered from the reproduction application and the network 300 may be stored. The storage unit 140 may include a flash memory, a hard disk, a multimedia card micro type memory (eg, SD or XD memory, etc.), a RAM, a ROM, and the like. ROM) and a storage medium.

The output unit 150 displays information on a series of operation states and operation results that occur during the functioning of the terminal 100. In particular, the output unit 150 of the present invention may display various information related to the execution of the playback application.

As described above, the output unit 150 may be implemented in the form of a single touch panel (or touch screen) together with the input unit 120, and when implemented together with the input unit 120, a user's touch operation. Various information generated according to the present invention can be displayed.

In addition, the output unit 150 of the present invention as described above is a liquid crystal display (LCD), thin film transistor LCD (TFT-LCD), organic light emitting diodes (OLED), light emitting diodes (LED), AMOLED (Active Matrix) Organic LED), a flexible display (Flexible display) and a three-dimensional display (3 Dimension) and the like. Some of these displays may also be configured to be transparent or light transmissive so that they can be seen from the outside. It may be configured in the form of a transparent display including a transparent OLED (TOLED).

As described above, main components of the terminal 100 have been described with reference to FIG. 2. However, not all components illustrated in FIG. 2 are essential components, and the terminal 100 may be implemented by more components than the illustrated components, and the terminal 100 may be implemented by fewer components. It may be implemented. For example, the terminal 100 may further include a sound source output unit (not shown) for converting a sound source, which is an electrical signal, into an analog signal and outputting the analog signal.

In addition, the position of the main components of the terminal 100 shown in FIG. 2 may be changed for convenience or other reasons.

In addition, the specific operation of the terminal 100 according to an embodiment of the present invention will be more clearly understood through the flowchart described below.

Hereinafter, the main configuration and operation method of the streaming server 200 according to an embodiment of the present invention.

3 is a block diagram showing a main configuration of a streaming server according to an embodiment of the present invention, Figure 4 is a block diagram showing a main configuration of an encoding module according to an embodiment of the present invention.

First, referring to FIGS. 1 and 3, the streaming server 200 according to an embodiment of the present invention may include a server communication unit 210, a server control unit 220, and a server storage unit 230.

In more detail with respect to each component, the server communication unit 210 serves to transmit and receive the necessary information with the terminal 100 through the communication network (300).

The server controller 220 includes an encoding module 221, an MPD generation module 222, and a service support module 223.

Here, the 'module' is a component that performs a predetermined function, respectively, can be implemented in hardware, software, or a combination of hardware and software. For example, the 'module' may mean a program module, which is executed by a processor to perform a predetermined function, software components, object-oriented software components, class components and Components such as task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, data, databases, data structures, tables, arrays , And variables. In addition, the functionality provided in the components and 'modules' may be combined into a smaller number of components and '~ modules' or further separated into additional components and '~ modules'.

First, the encoding module 221 may be configured to include a layering unit 221a, a substream generator 221b, and an index manager 221c, as shown in FIG. 4, wherein the layering unit 221a may be any one. The bitstream for each layer may be generated by layering the content of the layer into a base layer and an enhancement layer. The substream generator 221b may divide and generate the bitstreams of the layered layers into a predetermined number or more of substreams.

The index manager 221c may assign an index to each of the generated substreams.

The MPD generation module 223 generates metadata corresponding to the index, and the substream of the content is cached in any one cache device in which the substream delivered to the requesting terminal is distributed in the vicinity of the terminal. If so, it receives the caching information from the cache device, and serves to modify the metadata according to the received caching information.

The service support module 223 may control the overall process for transmitting content to the terminal 100 at the request of the terminal 100. For example, if content is transmitted to registered users, membership authentication may be performed. In addition, it plays a role of transmitting metadata to the terminal 100, and may support a process of smoothly transferring the substreams stored in the plurality of cache apparatuses 250 or the database server to the terminal 100.

The server storage unit 230 stores information related to performance of the streaming server 200 of the present invention, and in particular, may store and manage the MPD information 231.

In addition, although not shown in the drawing, when the streaming server 200 of the present invention provides a service to a registered user, personal information for membership registration and authentication may be stored and managed. In addition, when storing and managing a substream in a storage location in the streaming server 2000 of the present invention, it may include the corresponding substream.

The specific operation of the streaming server 200 according to an embodiment of the present invention will be more clearly understood through the flow chart described below.

Hereinafter, a content transmission method according to an embodiment of the present invention will be described with reference to FIGS. 5 to 8.

5 is a flowchart illustrating a content delivery method according to an embodiment of the present invention, and FIGS. 6 to 8 are exemplary diagrams for describing a content delivery method according to an embodiment of the present invention.

Before describing a content transmission method according to an exemplary embodiment of the present disclosure with reference to FIG. 5, the streaming server 200 according to an exemplary embodiment of the present disclosure is assumed to be a set of a plurality of server types. In this case, a server capable of performing an encoding process including an encoding module among a plurality of servers is referred to as the streaming server 200 of the present invention, and the remaining servers store the divided sub-screens under the control of the streaming server 200. It is assumed that the database server is a server. However, the present invention is not limited to the above structure, and the streaming server 200 may include a plurality of storage locations, and the streaming server 200 may directly store the subscription.

In the content transmission method according to an embodiment of the present invention, the streaming server 200 encodes and stores the content in order to use the storage space more efficiently and maximizes network traffic, and then transmits the content. The process of storing the content in the form of a plurality of substreams may be performed.

1 and 5, the streaming server 200 of the present invention performs scalable encoding of any one content. Scalable encoding means generating a bitstream by layering layers at different frame rates. According to an embodiment of the present invention, it is assumed that the scalable high efficiency video coding (SHVC) scheme, which is one of scalable encoding techniques, is used. However, the present invention is not limited thereto and various scalable encoding techniques may be used.

The streaming server 200 of the present invention may generate a bitstream by layering a base layer having a lower frame rate than the original picture and an enhancement layer obtained by combining the base layer with the base layer to obtain the original picture. (S101). Here, the streaming server 200 according to an embodiment of the present invention may layer into various layers according to frame rates other than the two layers. For example, one base layer may be generated, but a plurality of enhancement layers may be generated for each frame rate.

Thereafter, the streaming server 200 divides the base layer bitstream and the enhancement layer bitstream into a predetermined number of substreams to generate a substream (S103). This will be described in detail with reference to FIG. 6. The encoding module of the streaming server 200 of the present invention generates a bitstream by layering original content into at least two layers. If the method of generating and layering original content into a base layer bitstream and an enhancement layer bitstream is a general scalable encoding technology, the encoding module of the streaming server 200 of the present invention divides each bitstream into substreams having a variable size. Its characteristics are that it produces.

In addition, the streaming server 200 of the present invention checks the network status (connection status with the terminal, average speed and delay amount, bandwidth availability, the number of connected terminals, etc.), and varies the size of the substream according to the confirmed network status Can be set to In addition, if any one of the terminal 100 has requested the content and the performance information (available buffer amount, etc.) of the decoding module that can be processed by the terminal 100 can be checked, the performance information of the decoding module is considered. A variable sized substream may be generated.

In addition, the streaming server 200 of the present invention may generate a variable sized subscription according to the information on the storage location. For example, when the streaming server 200 of the present invention is divided into streaming servers A and B, the storage location of the streaming server A can be processed in units of 4 kb, and the storage location of the streaming server B can be processed in units of 8 kb. The streaming server 200 that performs encoding may generate a subscription in consideration of the processing unit of the storage location.

Thereafter, the streaming server 200 assigns an index to each substream (S105). In this case, the index is used to identify the substreams and may include identification information (ID) for identifying each substream. In addition, the substreams of the present invention can be grouped into a plurality of fragments (fragments), the fragments of the present invention may be a condition that is grouped by a specific reference unit. For example, the video content may be grouped in units of scenes, and a corresponding group may be assigned a fragment ID, and an index may be set to recognize that the substream is the same fragment. In addition, the index of the present invention may include identification information on a storage location. That is, the first substream may be stored in the first streaming server, and the second substream may be stored in the third streaming server, so that the terminal 100 may receive and use the substream at a corresponding storage location later. The index of the present invention may be configured to include identification information about a storage location.

7 illustrates that an index is assigned for each substream according to an embodiment of the present invention. The base layer bitstream is divided into 19 or more substreams, and each substream is identification information and a substream for substream identification. Sub-indexes used to distinguish fragments, which are groups, and index information of identification information (d) of a storage location may be provided, and each substream may be given a URL based on the index information. .

Thereafter, the streaming server 200 stores each substream (S107). At this time, the streaming server 200 of the present invention may store each substream divided in any one bitstream in different storage locations. For example, when there are ten sub streams A1, A2, A3, A4, A5, A6, A7, A8, A9, and A10 divided in the bitstream, A1, A3, and A5 represent the first streaming server, A2. , A4, A6 and A10 may be stored in the second streaming server, and A7, A8 and A9 may be stored in the third streaming server.

In addition, the streaming server 200 of the present invention may modify the storage location identification information of the index given in step S105 when the storage location of each substream is changed or needs to be modified.

In addition, the streaming server 200 of the present invention may interwork with a plurality of cache devices 350 distributed in the vicinity of the terminal 100, and any one of the cache devices in the process of transmitting a substream to the terminal 100. When the substream is cached at 350 and received from the cache device 350, the streaming server 200 may modify metadata information so that the cache device 350 provides the substream. As described above, when the cache device 350 caches only a part of the content and notifies the streaming server 200 instead of caching all of the high-capacity content, the streaming server 200 modifies the metadata accordingly. Afterwards, the CDN service is more easily applied to the terminal 100 through the distribution process.

In addition, the streaming server 200 of the present invention will generate the metadata for the index generated corresponding to each substream (S109). The metadata of the present invention means media presentation description (MPD) of content. Here, MPD means a stylized description of a media presentation, and the MPD of the present invention may be MPD of Dynamic and Adaptive HTTP Streaming of MEPG of MPEG.

In addition, the streaming server 200 according to an embodiment of the present invention may generate a plurality of metadata corresponding to any one content. That is, a plurality of metadata is generated in consideration of the performance of the terminal 100. As described above, the streaming server 200 of the present invention may generate a bitstream by layering content into a plurality of layers. When the specification of the terminal 100 is a high specification, all of the original content of high quality may be reproduced. In this case, the metadata may include information about all layers constituting the original content. On the other hand, if the specification of the terminal 100 is low, it may not be possible to reproduce the original content of high quality, so that the terminal 100 receives the base layer only by configuring the metadata including only the information on the base layer Can be processed to play.

One example of the metadata of the present invention is shown in FIG.

8 illustrates an example of metadata along the format of the MPD. The MPD is a description of a representation (or representation) of media to be delivered to the terminal 100 as described above. description). That is, the MPD describes combinations of video, audio, and language that the terminal 100 can access.

Briefly describing the structure of the MPD, the MPD may define a format for indicating resource identifiers for a segment. The MPD may provide a context for the identified resources in the media presentation, where the resource identifiers are HTTP-URLs and may be limited by the byte range attribute.

Each period is divided into fragments, where fragments may be used in the same sense. Segment is a term for Generation Partnership Project (3GPP) adaptive HTTP streaming.

A fragment (segment) is a part of a response to an HTTP / 1.1 GET request for an HTTP-URL (or a GET request for a portion indicated by a byte range), as defined in RFC 2616, for example. Refers to an entity body, and a sub-segment may refer to the smallest unit in segments that can be indexed by the segment index at the segment level. have.

In addition, one period may include two or more fragment sets, and each of the sets of fragments may be referred to as a representation. In addition, the representation may be referred to as an alternative.

Representation is a structured collection of one or more media components within one period. Representation is an alternative to media content or a subset of media content, with different encoding choices, such as bitrate, resolution, language, codec, and the like. alternative) may be one of the choices. That is, the representation may represent a combination of video, audio, language, and the like that may constitute media.

The MPD (or MPD element) provides descriptive information that enables the terminal 100 to select one or more representations, in other words suitable for accessing segments and providing streaming services to the user. (appropriate) A document containing metadata required by the DASH client to construct HTTP-URLs. HTTP-URLs can be absolute or relative. Such an MPD may be implemented in the form of an XML-document, and the MPD may include various MPD elements as described above, but may include only one MPD element.

In particular, the MPD of the present invention must include segment address information, subindex identification information, and integer type storage location identification information among the above-described elements.

Table 1

When the metadata generation is completed, the streaming server 200 of the present invention transmits the metadata to the corresponding terminal 100 (S111). In this case, as described above, suitable metadata may be selected and transmitted to the terminal 100 according to the specification of the terminal 100.

In addition, the streaming server 200 of the present invention may transmit a substream to the terminal 100 according to the request of the terminal 100.

In this case, when the streaming server 200 of the present invention is implemented as a streaming server for encoding and a database server for storing a substream, the terminal 100 is stored in a database server in which the streaming server for encoding stores a substream. The substream may be delivered to the terminal 100 directly from the corresponding database server by transmitting a request of the ().

In addition, the cache device 350 located in the process of transmitting the substream from the streaming server 200 to the corresponding terminal 100 may cache and store the substream and transmit the same to the streaming server 200. The streaming server 200 that has received this report may modify and edit the metadata of the content, and when another terminal 100 requests the corresponding content, the streaming server 200 may manage to receive the content from the cache device 350.

Hereinafter, an operation of the terminal 100 according to an exemplary embodiment of the present invention will be described.

1 and 9, the terminal 100 according to an embodiment of the present invention executes the playback application provided (S201). Here, the playback application performs a function of playing back the content provided by the streaming server 200. For example, it may be an application capable of playing high quality content provided by the streaming server 200. However, the present invention is not limited thereto, and any application (for example, a browser) may be a playback application of the present invention as long as the streaming server 200 can play content provided by the streaming server 200.

In addition, the playback application of the present invention is preferably downloaded in advance from the streaming server 200 or a separate content store is installed in the terminal 100, but is not limited thereto, and may execute the playback application in a cloud manner. .

Thereafter, the terminal 100 of the present invention checks the MPD which is the metadata file (S203). Through the MPD, the terminal 100 of the present invention may check address information (URL) for each substream, and may request and receive a substream from a corresponding device (S205 to S207). At this time, the terminal 100 of the present invention may check the sub-index information for each sub-stream, and if the sub-index information is the same, it can request and receive the sub-stream at the same time. In addition, the substreams of the present invention may be stored in different places, for example, the substreams may be stored in a cache device 350 distributed in the vicinity of the terminal 100 and the streaming server 200 or the streaming server 200 ) Can be distributed and stored in a database server that can interoperate with.

The terminal 100 of the present invention may simultaneously request and simultaneously receive content for each substream having the same subindex (S205 to S207), and decode the received substream to be reproduced in units of fragments (S209).

In addition, the terminal 100 of the present invention may selectively request a content substream using metadata of the content. For example, when the state of the terminal 100 or the network state is unstable, the terminal 100 checks the metadata of the content and selectively requests the content stream so that only the low-capacity content is received and reproduced even if the content is high-capacity.

In the above, a content transmission method supporting scalable encoding according to an embodiment of the present invention has been described.

The content transmission method supporting scalable encoding of the present invention as described above is generated by dividing a bitstream of a base layer and an enhancement layer layered in any one content into a predetermined number or more of substreams. And assigning and storing an index corresponding to each of the generated substreams, generating metadata for the index, and transmitting the metadata to the terminal that requested the content, and at the request of the terminal. And transmitting the substream of the content to the terminal.

Such computer-readable media suitable for storing computer program instructions and data include, for example, recording media comprising magnetic media, such as hard disks, floppy disks, and magnetic tape, and compact disk read only memory (CD-ROM). , Optical media such as Digital Video Disk (DVD), magneto-optical media such as Floppy Disk, and ROM (Read Only Memory), RAM And a semiconductor memory such as a random access memory, a flash memory, an erasable programmable ROM (EPROM), and an electrically erasable programmable ROM (EEPROM). The processor and memory can be supplemented by or integrated with special purpose logic circuitry.

The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. In addition, a functional program for implementing the present invention, codes and code segments associated therewith may be used in consideration of a system environment of a computer that reads a recording medium and executes the program. It may be easily inferred or changed by.

In addition, the computer program recorded on the computer-readable recording medium as described above includes instructions for performing the functions as described above, distributed and distributed through the recording medium to be read and installed on a specific device, a specific computer, and executed. Thus, the above functions can be executed.

Here, in order for a computer to read a program recorded on a recording medium and execute functions implemented as a program, the above-described computer program is a C, C ++ that can be read by the computer's processor (CPU) through the computer's device interface (Interface) Code for a program instruction coded in a computer language such as JAVA, machine language, or the like may be included.

Such code may include a function code associated with a function or the like that defines the above-described functions, and may include execution procedure-related control code necessary for a processor of the computer to execute the above-described functions according to a predetermined procedure. In addition, the code may further include memory reference-related code for additional information or media required for a processor of the computer to execute the above-described functions at which location (address address) of the computer's internal or external memory. . In addition, if the processor of the computer needs to communicate with any other computer or server on the remote in order to execute the above functions, the code may be used to determine which computer the processor of the computer uses the communication module of the computer on the remote. It may further include communication-related codes such as how to communicate with other computers or servers, and what information or media should be transmitted and received during communication.

Although the specification includes numerous specific implementation details, these should not be construed as limiting to any invention or the scope of the claims, but rather as a description of features that may be specific to a particular embodiment of a particular invention. It must be understood. Certain features that are described in this specification in the context of separate embodiments may be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable subcombination. Furthermore, while the features may operate in a particular combination and may be initially depicted as so claimed, one or more features from the claimed combination may in some cases be excluded from the combination, the claimed combination being a subcombination Or a combination of subcombinations.

Likewise, although the operations are depicted in the drawings in a specific order, it should not be understood that such operations must be performed in the specific order or sequential order shown in order to obtain desirable results or that all illustrated operations must be performed. In certain cases, multitasking and parallel processing may be advantageous. Moreover, the separation of the various system components of the above-described embodiments should not be understood as requiring such separation in all embodiments, and the described program components and systems will generally be integrated together into a single software product or packaged into multiple software products. It should be understood that it can.

According to the present invention, when encoding content by a scalable encoding method, by dividing a bitstream of each layer into a predetermined number or more of substreams, assigning an index to each substream, and defining metadata for the index. Even if the substreams are located in different storage locations, the terminal can easily receive and use contents by referring to the indexes of the substreams, thereby contributing to the development of the service industry.

In addition, the present invention has industrial applicability because the present invention is not only sufficiently commercially available or commercially viable, but also practically clearly implemented.

Claims

Generating by dividing a bitstream of a base layer and an enhancement layer layered in any one content into a predetermined number or more of substreams;

Assigning and storing an index corresponding to each of the generated substreams; And

Generating metadata for the index and transmitting the metadata to a terminal that has requested the content, and transmitting a substream of the content to the terminal at the request of the terminal;

Content delivery method that supports scalable encoding comprising a.
The method of claim 1,

The dividing step

The bitstream of each layered layer is divided into a predetermined number or more of substreams in consideration of at least one of state information of a network, performance information of a terminal requesting the content, and performance information of a storage location capable of storing the substream. And a content encoding method supporting scalable encoding.
The method of claim 1,

The index is

Contents supporting scalable encoding comprising at least one of identification information for identifying the substream, fragment identification information including the substream, and identification information on a storage location where the substream is stored. Transmission method.
The method of claim 1,

The metadata is

And a plurality of information generated corresponding to the performance information of the terminal or including information for defining elements that can be received in consideration of the performance of the terminal.
The method of claim 1,

After the transmitting step,

Receiving the caching information from the cache device when the substream of the content is cached in any one cache device distributed in the vicinity of the terminal; And

Modifying the metadata according to the received caching information;

Content delivery method that supports scalable encoding comprising a.
A computer-readable recording medium having recorded thereon a program for executing the content transmission method supporting the scalable encoding according to any one of claims 1 to 6.
A layering unit for layering any content into a base layer and an enhancement layer to generate a bitstream for each layer;

A substream generator for dividing the bitstreams of the layered layers into a predetermined number or more of substreams; And

And an encoding module configured to provide an index corresponding to each of the generated substreams.
The method of claim 7, wherein

When the substream of the content is cached in any one cache device generating the metadata corresponding to the index and the substream delivered to the requesting terminal is distributed in the vicinity of the terminal, An MPD generation module that receives the caching information and modifies the metadata according to the received caching information;

Streaming server, characterized in that it further comprises.