KR20150010589A - Apparatus and method for providing contents - Google Patents

Abstract

A method of receiving content in a client is provided. The method according to an embodiment includes: receiving a spatial set identifier of at least one spatial object from a server; requesting a first content corresponding to the spatial set identifier from the server; and receiving the first content corresponding to the request from the server.

Description

[0001] APPARATUS AND METHOD FOR PROVIDING CONTENTS [0002]

TECHNICAL FIELD [0002] The technical field of the present invention relates to streaming contents providing technology, and more particularly, to an apparatus and method for providing media contents using adaptive streaming.

Streaming is one of the methods for transmitting and reproducing multimedia contents such as sound and video. The client can play the above content while receiving the content through streaming.

The adaptive streaming service means providing a streaming service through a communication method composed of a client's request and a server's response to the request.

A client may request a media sequence suitable for its environment (e.g., its own transport channel) through an adaptive streaming service, and the server may request a media sequence corresponding to the client's request among various quality media sequences of its own .

Adaptive streaming services can be provided based on various protocols.

The HTTP adaptive streaming service means an adaptive streaming service provided based on the HTTP protocol. The client of the HTTP adaptive streaming service can receive the content from the server using the HTTP protocol and can transmit the request related to the streaming service to the server.

At present, a method of downloading and simultaneously streaming video using the TCP or HTTP protocol is widely used. Meanwhile, MPEG, a video standardization organization, standardizes a method for downloading and streaming video using the HTTP protocol through a project called Dynamic Adaptive Streaming over HTTP (DASH). In the conventional TCP or HTTP based video transmission method and MPEG-DASH, one program is divided into time divisional segments, and a method of sequentially downloading and reproducing the segments is used. In this process, it is possible to select a suitable bandwidth or a video type according to the environment of the network or the terminal.

The present disclosure can provide an apparatus and a method for transmitting spatially divided moving picture contents on a spatial segment basis.

A method of receiving a client's content according to an embodiment includes receiving a spatial set identifier for a group of at least one spatial object from a server, requesting a first content corresponding to the spatial set identifier to the server And receiving the first content corresponding to the request from the server.

The spatial set identifier may identify a tile group that includes at least one tile in which a full-frame video is spatially divided.

The first content may be video corresponding to the tile group.

The spatial set identifier may group a set of spatial objects.

The step of receiving the spatial set identifier may receive metadata including the spatial set identifier.

The metadata may be a media presentation description (MPD) of the content.

The media information may include a spatial relationship description (SRD).

The spatial relationship description may include at least one of the spatial set identifier, the x-axis position of the spatial object, the y-axis position, the width, the height, the reference space width, and the reference space height.

The step of requesting the first content to the server may send a request to the server including a URL corresponding to the first content.

The URL may include a URL corresponding to a tiled spatially segmented full-frame video.

A server content delivery method according to another embodiment includes sending a spatial set identifier for a group of at least one spatial object to a client, receiving a first content corresponding to the spatial set identifier from the client And transmitting the first content corresponding to the request to the client.

The spatial set identifier may include at least one tile in which a full-frame video is spatially divided.

The first content may be video corresponding to the tile group.

The spatial set identifier may group a set of spatial objects.

Wherein the step of transmitting the spatial set identifier comprises transmitting at least one of the metadata including at least one of the spatial set identifier, the x-axis position, the y-axis position, the width, the height, the reference space width and the reference space height of the spatial object have.

The metadata may be a media presentation description (MPD) of the content.

The media information may include a spatial relationship description (SRD).

The spatial relationship description may include the spatial set identifier.

The step of receiving the first content may receive a request from the client including a URL corresponding to the first content.

The URL may include a URL corresponding to a tiled spatially segmented full-frame video.

According to various embodiments, an apparatus and method for transmitting spatially divided moving picture contents in spatial segment units can be provided.

The location of each spatial segment can be simply displayed in the case of streaming using a spatial segment that divides one content, a subset of spatial segments can be provided, and separate index information can be provided have.

FIG. 1 is a conceptual diagram of video content that is spatially divided according to an exemplary embodiment.
2 is a flowchart illustrating a signal processing process according to an embodiment.
3 is a hierarchical view of a spatial segmentation method according to one embodiment.
4 is a hierarchical view of a spatial segmentation method according to another embodiment.
5 is a structural view of a client according to an embodiment of the present invention.
6 is a structural diagram of a client according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to or limited by the embodiments. Like reference symbols in the drawings denote like elements.

Dynamic Adaptive Streaming over HTTP (DASH) enables the delivery of media content from an HTTP server to an HTTP client, and 2) the content of content by standard HTTP caches. Specifies the formats that enable caching.

A media component may be any audio, video, or timed text having certain attributes, such as, for example, bandwidth, language or resolution. Is an encoded version of an individual media type.

Media content is a collection of media components that have a common timeline, such as video, audio, and subtitles. In addition, the media components may include relationships (e.g., individually, jointly, or mutually exclusive) as to whether the media components will be presented as a program or movie .

The media content and the content may be used in the same sense.

A media presentation is a structured collection of data that establishes bounded, unbounded presentation of media content composed of components of continuous media.

That is, the media presentation is a structured collection of data accessible to the DASH client to provide the streaming service to the user.

A media presentation description (MPD) may be a formalized description of a media presentation.

The media presentation may be described by the MPD, including possible updates of the MPD.

The content may be content on demand or live content.

The content may be divided into one or more intervals. That is, the content may include one or more intervals.

Interval and period can be used in the same sense. The period may be a term of 3GPP (Generation Partnership Project) adaptive HTTP streaming.

The period may be the interval of the media presentation. A sequence of all the cycles constitutes a media presentation.

That is, the media presentation may include one or more periods.

The one or more intervals may be a base unit. The one or more intervals may be described by signaling the metadata. That is, the metadata may describe each of one or more intervals.

The above metadata may be MPD.

The MPD may define a format for announcing resource identifiers for the segment. The MPD can provide a context for the identified resources within the media presentation. The resource identifiers may be HTTP-URLs. URLs may be limited by byte range attributes.

Each interval can be divided into fragments.

Fragments and segments may be used interchangeably. The segment may be a term of 3GPP (Generation Partnership Project) adaptive HTTP streaming.

The segment may be an object of a response to an HTTP / 1.1 GET request (or a GET request for a portion indicated by the byte range) to an HTTP-URL as defined in RFC 2616, entity body. Metadata can include URL attributes and scope attributes. The client can receive the bytes specified by the scope attribute from the URL pointed to by the URL attribute. That is, the bytes may be received by the partial HTTP GET command for the URL, indicated by the byte range, where the bytes specified by the range attribute may represent the segment described above.

The range attribute may indicate multiple byte ranges.

The client can play the media content using the received bytes (i.e., segments).

A sub-segment may mean a smallest unit in segments that can be indexed by a segment index at the segment level.

There can be a set of two or more fragments corresponding to one interval. Each of the sets of fragments is named as an alternative.

Alternatives and representations (or expressions) may be used interchangeably.

Each cycle may include one or more groups.

Each group may contain one or more representations of the same media content.

A representation is a structured collection of one or more media components in a cycle.

The MPD (or MPD element) provides descriptive information that enables the client to select one or more presentations.

A random access point (RAP) is a specific location within a media segment. The RAP is identified as being the location where it can only continue to play back from the location of the RAP using only the information contained within the media segment.

Each representation may consist of one or more segments. That is, the representation may include one or more segments.

MPD is a document that contains metadata required by a DASH client to 1) access segments and 2) configure the appropriate HTTP-URLs to provide a streaming service to a user. HTTP-URLs can be absolute or relative.

MPD can be an XML-document.

The MPD may include an MPD element. The MPD may contain only one MPD element.

The client may be a DASH client.

DASH clients are compatible with the clients specified in RFC 2616.

A DASH client can use the HTTP GET method or HTTP partial GET method, as specified in RFC 2616, to contact segments or portions of segments.

FIG. 1 is a conceptual diagram of video content that is spatially divided according to an exemplary embodiment.

As shown in FIG. 1, one content may be spatially separated into, for example, 24 segments. Here the segment may be named a tile or a piece. Each of the segments may be assigned a segment identification (segment ID).

On the other hand, a spatial relationship can be defined. The spatial relationship may relate to video representing the spatial portion of a full-frame video. The spatial portion may be a region of interest or a tile described in terms of position and size. The technique may provide additional choices for the client as a term of adaptation.

In addition, a spatial relationship description (SRD) can be defined. Spatial relationship description allows media presentation authors to express relationships between spatial objects. A spatial object may be represented by one of an adaptation set or a sub-representation. The spatial relationship may represent video representing the spatial portion of the full-frame video. In Figure 1, a video representing a spatial portion of a full-frame video may be referred to as a spatial object. Alternatively, a group of videos representing a spatial portion may be referred to as a spatial object. To ensure compatibility with legacy clients, MPD authors can use SupplementalProperty and EssentialProperty to be interpreted by legacy clients even after at least one presentation has discarded an element containing EssentialProperty.

A DASH client that has grasped the spatial relationship description (SRD) can use the SRD annotation to select the spatial portion of the full-frame presentation or full-frame presentation to suit the needs. This saves bandwidth and client-side computation, which results from preventing full-frame fetching, decoding, and cropping.

According to an embodiment, a method of arranging the number of the horizontal segments, the vertical segments and the spatial segments of the spatial segments when the sizes occupied by the respective segments are the same is described. In each of the space segment description units, an identifier Can be described.

For example, as shown in FIGS. 1 (a) and 1 (b), a state in which 24 spatial segments are divided can be listed as a horizontal raster scan method or a vertical raster scan method. In this case, the information to be actually transmitted may include the number of horizontal segments, the number of vertical segments, and the directionality of the segments.

In addition, the coordinates (x, y), the width (w) and height (h) of the tile and the width (W) and height (H) of the full- ) Can also be included in the SRD and can be named SRD parameters. Or the SRD may include an identifier of the source including the full-frame video or tile.

The source identifier (source_id) parameter may provide a unique identifier for the source of the content within the period. The source identifier may implicitly define a coordinate system associated with the source; The coordinate system includes an arbitrary origin (0; 0), and the x-axis extends leftward and rightward, and the y-axis extends upward and downward. All SRDs sharing the same source identifier contain the same origin and coordinate axes. The spatial relationship for a spatial object using the SRD of different source identifier values is undefined.

On the other hand, the x and y parameters represent the two-dimensional position associated with the spatial object in the coordinate system associated with the source. The W and h parameters represent the two-dimensional size associated with the spatial object within the coordinate system associated with the source. The values of the X, y, w and h parameters may be relative to the values of the W and H parameters. The location (x, y) and size (w, h) of the SRD sharing the same source identifier value can be compared after considering the size of the reference space first, that is, the x and w values are divided by the W value divided), y and h are divided by H value.

Here, the different W and H values may be used in different descriptors to provide position and size information within different units.

A group identifier may be defined. The group identifier may be an identifier indicating a group including a tile included in the base view at the start of reproduction of the content or according to a user's request, and will be described in more detail later. On the other hand, the group identifier may be referred to as a spatial set identifier (spatial_set_id). Here, the spatial set identifier has the same meaning as the group identifier, but may be otherwise defined as an identifier for a group of spatial objects.

2 is a flowchart illustrating a signal processing process according to an embodiment.

As shown in FIG. 2, the client 100 and the server 110 can communicate with each other. The client 100 may be a DASH client. DASH clients are compatible with the clients specified in RFC 2616.

A DASH client can use the HTTP GET method or HTTP partial GET method, as specified in RFC 2616, to contact segments or portions of segments.

Server 110 may host DASH segments. The server 110 may be compatible with the server specified in RFC 2616.

At step 120, the client 100 receives 1) metadata for the content or 2) metadata for a particular interval of the content from the server 110. That is, the server 110 transmits 1) metadata about the content or metadata about a specific interval of the content to the client 100. A specific interval indicates an interval currently processed among one or more intervals constituting the content.

Here, the metadata may be a media presentation description (MPD) of the media content. In addition, the media information may include an SRD, and the SRD may include at least one of a group identification and a tile identifier. The group identifier may be an identifier indicating a group including a tile included in the basic view at the start of reproduction of the content or according to a user's request. In other words, the group identifier may be an identifier for grouping a set of spatial representations. For example, in the SRD as shown in FIG. 1A, a tile group having a group identifier of "0 " may be set to a group including tiles of 15, 16, 21, In addition, a tile group having a group identifier of "1 " may be set to a group including 11, 12, 17, The group identifier may be 0 or a natural number.

On the other hand, content represented by one of an adaptation set or a sub-representation may be defined as a spatial object. The group identifier may be defined as an identifier for a group of spatial objects.

For example, in step 120, it is assumed that the client 100 receives metadata including the group identifier of "1 " from the server 110.

At step 130, the client 100 processes the metadata for a particular interval. For example, the client 100 can confirm the group identifier and confirm the content to be received.

At step 140, the client 100 may request the server 110 for content or fragments. The client 100 may request the server 110 for suitable content for a specific interval based on the metadata processing. That is, the requested content is selected based on the metadata. For example, the client 100 may request content that includes a tile group corresponding to the group identifier. In one embodiment, client 100 may send a request to server 110 that includes a URL corresponding to a tile group. The request here may include a plurality of URLs. For example, the client 100 may send a request to the server 110 that includes a URL for each of the tiles containing the tile identifier of 11, 12, 17, 18.

At step 150, the server 110 sends appropriate content to the client 100 for each request from the client 100. [ The client 100 receives the content from the server. For example, the client 100 may receive tiles, i. E., A group of tiles, containing tile identifiers of 11,12, 17,18.

Next, the entire process is executed from the beginning. That is, step 120 is repeated for the next interval of the specific interval.

The client 100 may play the content using the received fragment as the steps 120 through 150 are repeated.

In accordance with the foregoing, the client 100 may receive content that includes partial tiles rather than full-frame video. Thus, the bandwidth and the amount of computation can be significantly reduced.

Meanwhile, the above-described embodiment is merely an example, and can be equally applied to a tile identifier that is not a group identifier. More specifically, the client 100 may receive metadata including a tile identifier. The client 100 may send a request to the server 110 that includes a URL corresponding to the tile identifier. The server 110 may transmit the content to the client 100. [

Hereinafter, a spatial segment display method according to various embodiments will be described.

3 is a hierarchical view of a spatial segmentation method according to one embodiment.

As shown in FIG. 3, a method of arranging the horizontal number, the vertical number, and the space segment of the space segment in order to display the space segment in the period element of the MPD defined in the DASH is described, The set (AddaptationSet) element may describe an identifier that can be a simple number or a sequence. That is, it is possible to add a typeOfNumbering to the period element and add a tile identifier (tileId) to each adaptation set so as to arrange the horizontal number of the spatial segment tile as numOfColumns, the vertical number as numOfRows, So that the user can perceive the position. In the embodiment of FIG. 3, it is described that the number of horizontal pixels is 6, the number of vertical pixels is 4, and the method of arranging the spatial segments is a horizontal raster scanning method. The following may be semantics and XML to illustrate this.

 numOfColumns: number of tile columns

 numOfRows: number of tile rows

 typeOfNumbering: numbering or scanning type of tiles

tileId: Sequential number to indicate a tile and its position

  <xs: complexType name = "PeriodType">

    <xs: sequence>

      <xs: element name = "BaseURL" type = "BaseURLType" minOccurs = "0" maxOccurs = "unbounded" />

      <xs: element name = "SegmentBase" type = "SegmentBaseType" minOccurs = "0" />

      <xs: element name = "SegmentList" type = "SegmentListType" minOccurs = "0" />

      <xs: element name = "SegmentTemplate" type = "SegmentTemplateType" minOccurs = "0" />

      <xs: element name = "AdaptationSet" type = "AdaptationSetType" minOccurs = "0" maxOccurs = "unbounded" />

      <xs: element name = "Subset" type = "SubsetType" minOccurs = "0" maxOccurs = "unbounded" />

<xs: any namespace = "## other" processContents = "lax" minOccurs = "0" maxOccurs = "unbounded" />

    </ xs: sequence>

    <xs: attribute ref = "xlink: href" />

    <xs: attribute ref = "xlink: actuate" default = "onRequest" />

    <xs: attribute name = "id" type = "xs: string" />

    <xs: attribute name = "start" type = "xs: duration" />

    <xs: attribute name = "duration" type = "xs: duration" />

    <xs: attribute name = "bitstreamSwitching" type = "xs: boolean" default = "false" />

    <xs: attribute name = "numOfColumns" type = "xs: unsignedInt" use = "optional" />

    <xs: attribute name = "numOfRows" type = "xs: unsignedInt" use = "optional" />

    <xs: attribute name = "typeOfNumbering" type = "xs: string" use = "optional" />

    <xs: anyAttribute namespace = "## other" processContents = "lax" />

  </ xs: complexType>

In another embodiment, a method of representing a subset of a spatial segment while simultaneously describing and delivering content for multiple spatial tiles enables a variety of applications. For example, a subset of spatial segments may be provided separately to specify a spatial region that is the center of the screen, or an area where significant events occur, such as a crucial scene in a sport. Also, the area that is the default view in the entire space can be displayed through a subset of space segments. To this end, subset information including a plurality of identifiers of spatial segments may be separately provided, which may be a group identifier.

For example, in the case of DASH, a subset of the tiles described by the SRD in the period of the MPD can be displayed at the start of playback of the content or a tile included in the basic view according to the user's request through a new element called a default view have.

Or another element such as a tile group (TileGroup), which is a subset of tiles in a period, to list spatial segment identifiers, or in another example, a subset of the elements included in the current MPD :: Period, It is also possible to extend this. For example, an extended subset (ExtendedSubSet) that extends an existing subset without affecting the semantics of an existing subset is defined, identifiers not included in the subset are added to the extended subset, and existing context attributes contains attribute) to reuse the space segment as shown below. The following may be semantics and XML to illustrate this.

 TileGroup id = 0, contains = "15,16,21,22"

DefaultView id = 1, contains = "11,12,17,18"

 ExtendedSubSet id = 0, contains = "15,16,21,22"

ExtendedSubSet id = 1, contains = "11,12,17,18"

  <xs: complexType name = "ExtendedSubsetType">

    <xs: complexContent>

      <xs: extension base = "SubsetType">

        <xs: attribute name = "id" type = "ID" use = "optional" />

      </ xs: extension>

    </ xs: complexContent>

</ xs: complexType>

4 is a hierarchical view of a spatial segmentation method according to another embodiment.

The method according to this embodiment allocates an index of each spatial segment. In other words, the present spatial segment description method has only identifier information, which is for indicating each spatial segment, but is not suitable for conveying additional information of each spatial segment. For example, when additional information is not provided, only the location information is provided for each spatial segment, and priority information or the like can not be displayed. Therefore, there is a need for a method for transmitting additional information such as priority information of the spatial segments and subset information of the same kind. The index attribute is transmitted together with the identifier information of each spatial segment, and the receiving terminal interprets the index information according to the promised method. For example, in the case of MPEG-DASH, an index attribute is added to each spatial segment information to transmit additional side information of each spatial segment. The significance of the index and how to utilize it promises between the author and the terminal in advance. The meaning of an index can be used as a first level information, and the same index can be used as a subset. The following may be semantics and XML to illustrate this.

 Role tileId = "ts1" index = "0"

 Role tileId = "ts2" index = "0"

 ...

 Role tileId = "ts24" index = "9"

5 is a structural diagram of a client 100 according to an embodiment of the present invention.

The control unit 510 performs steps 130 and 140. [ That is, the control unit 510 may process the metadata for the interval, and may select the content suitable for the interval based on the process.

The transceiver 520 performs step 120, step 140 and step 150. That is, the transceiver 520 receives the metadata of the interval of the content from the server 110, requests the server for the appropriate content for the interval, and receives the content from the server.

6 is a structural diagram of a client 100 according to an embodiment of the present invention.

The client 100 includes an access engine 610 and a media engine 620.

The access engine 610 may be a DASH access engine.

The access engine 610 receives metadata (e.g., MPD) from the server 110.

The access engine 610 configures the requests and issues the configured requests to the server 110.

The access engine 610 receives content (e.g., kender, segments, or segments) from the server 110.

The access engine 610 provides the content to the media engine 620.

The output of the access engine 610 is stored in the media (or media) of an MPEG container (e.g., ISO / IEC 14492-12 ISO Base Media File Format or ISO / IEC 13818-2 MPEG-2 Transport Stream) &Lt; / RTI &gt; In addition, the output of the access engine 610 may include timing information to map the internal timing of the media to the timeline of the media presentation.

The media engine 610 plays the provided content. That is, the media engine 610 may output the media using the media and timing information output from the access engine 610. [

The method according to an embodiment of the present invention can be implemented in the form of a program command which can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

Claims (20)

A content receiving method of a client,
Receiving a spatial set identifier for a group of at least one spatial object from a server;
Requesting a first content corresponding to the spatial set identifier to the server; And
Receiving the first content corresponding to the request from the server
And transmitting the content. The method according to claim 1,
Wherein the spatial set identifier identifies a tile group that includes at least one tile in which a full-frame video is spatially divided. 3. The method of claim 2,
Wherein the first content is video corresponding to the tile group. The method according to claim 1,
Wherein the spatial set identifier is a grouping of a set of spatial objects. The method according to claim 1,
Wherein the step of receiving the spatial set identifier comprises:
And receiving the metadata including the spatial set identifier. 6. The method of claim 5,
Wherein the metadata is a media presentation description (MPD) of the content. The method according to claim 6,
Wherein the media information includes a spatial relationship description (SRD). 8. The method of claim 7,
Wherein the spatial relationship description includes at least one of the spatial set identifier, the x-axis position of the spatial object, the y-axis position, the width, the height, the reference space width, and the reference space height. The method according to claim 1,
Wherein requesting the first content to the server comprises:
And transmits a request including the URL corresponding to the first content to the server. 10. The method of claim 9,
Wherein the URL comprises a URL corresponding to a tile in which a full-frame video is spatially segmented. In a content transmission method of a server,
Transmitting a spatial set identifier for a group of at least one spatial object to a client;
Receiving a request for a first content corresponding to the spatial set identifier from the client; And
Transmitting the first content corresponding to the request to the client
And transmitting the content. 12. The method of claim 11,
Wherein the spatial set identifier identifies a tile group that includes at least one tile in which a full-frame video is spatially divided. 13. The method of claim 12,
Wherein the first content is video corresponding to the tile group. 12. The method of claim 11,
Wherein the spatial set identifier is a grouping of a set of spatial objects. 12. The method of claim 11,
Wherein the step of transmitting the spatial set identifier comprises:
And transmitting the metadata including the spatial set identifier. 16. The method of claim 15,
Wherein the metadata is a media presentation description (MPD) of the content. 17. The method of claim 16,
Wherein the media information includes a spatial relationship description (SRD). 18. The method of claim 17,
Wherein the spatial relationship description includes at least one of the spatial set identifier, the x-axis position, the y-axis position, the width, the height, the reference space width, and the reference space height of the spatial object. 12. The method of claim 11,
The method of claim 1,
And a request including a URL corresponding to the first content is received from the client. 20. The method of claim 19,
Wherein the URL comprises a URL corresponding to a tile in which a full-frame video is spatially segmented.

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