KR100723747B1 - Method for generating database in media server - Google Patents

Abstract

The present invention relates to a method for creating a database in a media server. The present invention, generating information in the DB that can be made to the name of the object; And generating information in the DB for responding to the called action. When the media server providing CDS starts to run, it creates information in the DB that can be made into the object name for all the shared objects, and the information that needs to be searched inside the object is created in the DB when the action is called. . In addition, when the action is called, it checks whether the response information for the called action exists in the DB, and generates the response information for the called action only in the DB if it does not exist. Therefore, when implementing CDS using DB, the time taken for initial DB creation is reduced, and the DB for meta information is efficiently generated.

CDS, DB, Browse Action, Search Action, Media Server, Object

Description

{Method for generating database in media server}

1 illustrates an area in which each action provided by the CDS obtains information,

2 is a table in which the DB created in each step and the area of FIG. 1 are associated with each other.

3 shows the types of information required in each step,

4 is a flowchart illustrating an operation of a DB generating method in a media server according to the present invention.

The present invention relates to a method for creating a database in a media server that provides a CDS (Content Directory Service), and more particularly, a method for efficiently reducing an initial DB generation time by using a characteristic of a UPnP AV action in a media server that provides a CDS. It is about.

UPnP (Universal Plug and Play) is a network structure that connects all kinds of devices such as information appliances, wireless devices, and PCs. This provides easy connection between devices or the Internet in a standardized way without user intervention on a non-administrator network such as a home or small office.

UPnP extends the concept of Plug and Play, which used to control devices from traditional PCs, to connect devices to the network using Web protocols without requiring any user intervention. Thus, the device can access the network at any time and can inform other devices connected to the network of the IP address or function. You can also disconnect from the network without affecting other devices.

The UPnP network consists of devices that provide services and CPs that control the devices. A control point (CP) discovers various devices on a network, discovers what those devices serve, controls them, and receives events. Through this process, the CP that has obtained information about the UPnP devices operates by calling an action on the UPnP device and responding to the UPnP device.

In response to a call to the Browse action, the CDS (Content Directory Service) delivers meta information of its own content to the CP that called the action.

Meta information can be obtained simply from the file name, but sometimes the contents of the file must be examined and extracted.

Current methods for acquiring Meta information include obtaining information in real time, writing Meta information in a database (DB), or writing it in a file form. In fact, the method of writing down the file form and the writing down method in the DB do not have much problem even if they are unified by writing the information in the file. The reason is that DB is also a concept of writing in a file in a big sense.

The big difference between getting information in real time and writing it to a file is whether the information is volatile when the device loses power.

Note that there is no need to change the information significantly unless the file is actually removed. However, there may be a problem in sharing, ie, synchronizing, information about a file existing in a real file system with a file information written in a file. There is also a problem that it can take a lot of time initially to read all the information.

On the other hand, the method of reading the information of the file in real time from the real file system has the advantage that it can be synchronized, but there is a problem that the information disappears after one use. It may take a short time to read a short amount, but even a short amount may take a long time if you need to do a lot of calculations.

Therefore, the present invention was created in view of the above circumstances, and an object of the present invention is to provide a method for efficiently generating a DB for meta information by a server providing a CDS service.

Another object of the present invention is to provide a method for reducing a creation time when a server providing a CDS service initially creates a DB.

Still another object of the present invention is to provide a method of creating a DB by using a feature of a UPnP action, by a server providing a CDS service.

In order to achieve the above object, a DB generation method in a media server according to the present invention includes: one step of generating information in a DB that can be created by the name of an object; And generating at the DB information for responding to the called action.

The media server is a server that provides CDS, and the first step is performed when the media server starts up, and the media server is applied to all objects shared by recursively calling the Browse action with the BrowseDirectChildren flag for every tree under Root. It is characterized by generating information about DB. The information generated in the first step includes an object identifier, title, and class.

The second step may include checking whether response information about the called action exists in the DB; And if the response information does not exist, generating response information for the called action in the DB, and checking whether the response information for the called action exists in the DB is called action And based on a value of an input variable of the called action.

Response information for the action is classified according to the called action and stored in the DB. The action includes a Browse action and a Search action. In addition, the response information for the action is characterized in that it is stored in the DB as different items according to the value of the input variable included in the called action.

Response information for the Browse action is stored in DB as different items according to the values of ObjectID and BrowseFlag, which are input variables. The value of the BrowseFlag input variable is distinguished and stored according to BrowseDirectChildren and BrowseMetaData.

The response information for the Browse action is stored in the DB as different items according to the values of ObjectID and SortCriteria, which are input variables. The value of SortCriteria that CDS of the media server can support is provided through the GetSortCapabilities action. .

Response information for the Search action is stored in the DB according to the input variable ObjectID and the value of the search variable. The value of the search variable that can be supported by the media server's CDS is provided through the GetSearchCapabilities action. do.

The response information for the Browse action using the unique identifier of the specific container and the BrowseDirectChildren as the values of the ObjectID input variable and the BrowseFlag input variable, respectively, includes the number of objects included in the specific container, the size of each object, the creation time, and the creator. The response information for the Browse action, in which the unique identifier of the Item related to the AV media data and the BrowseMetaData are the values of the ObjectID input variable and the BrowseFlag input variable, respectively, includes the codec type, version, resolution, bit rate, and playback time of the item. Characterized in that it is included.

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

In general, the CDS is connected to a file system and informs the CP by expressing information about contents existing in the file system in a predetermined manner. Predetermined means does not necessarily inform the CP according to the construction of the file system. For example, it is possible to divide files scattered in several directories into categories and group them in a specific directory.

The two major roles of the media server are to allow the user to see information about the content that exists in the file system, and the other is to deliver the information needed to play the content to the CP or renderer. have. 3 illustrates this.

That is, the media server first provides information required for selecting a desired object, that is, a content, and plays the selected object when the user selects the desired object or when the user requests playback of the object. Provide the CP or renderer with the necessary information.

Information required for the user to select an object includes ObjectID, Title, Class information, etc., information necessary for the reproduction of the object is detailed attribute information of the object, for example, if the object is AV media data type and version Codec information such as, resolution, bit rate, playback time, and the like.

In general, when a user plays content stored in a media server in a UPnP network through a renderer, the user checks which objects are stored in the media server, selects a desired object, and then plays the selected object through the renderer. .

Therefore, it is not necessary to obtain various information necessary for playback until the stage of playing the object desired by the user comes. Of course, if you make perfect information in the DB beforehand, there is an advantage that you can check the detailed information of each object without spending additional time even before regenerating the object. However, if the amount of time it takes to obtain this information can be felt by the user, a user who does not need this information, such as a user who only wants to know what Objects' titles are stored on the media server, can also There may be a problem that you have to wait while creating the DB that contains detailed information on all objects.

In order to solve such a problem, the present invention uses a method of distributing and processing in steps according to the steps, rather than all of them at once. When this method is applied, the point in time when detailed meta information necessary for the reproduction of the object should be built in the DB and delivered to the user can be said to be just before the reproduction.

Objects stored on media servers providing UPnP CDS are shown to external CPs or renderers through the Browse action. Browse actions include objected, BrowseFlag, Filter, StartingIndex, RequestedCount, and SortCriteria as input parameters, and Result, NumberReturned, and TotalMatches as output variables.

Object of CDS is either Item or Container. An Item refers to a single piece of data, and a Container is a set of objects. In short, an Item can represent a single file and a Container can contain multiple files and folders. It can be called a folder. Each Container and Item are identified by a unique identifier (ObjectID).

To find out which Container or Item exists inside a specific Container, the Browse action should be called with the unique identifier of the specific Container as the value of the input variable objectID and the BrowseDirectChildren Flag as the value of the input variable BrowseFlag.

To know detailed information about a specific container or a specific item, a Browse action should be called that uses a unique identifier of a specific container or item as the value of an input variable objectID and a BrowseMetaData Flag as the value of an input variable BrowseFlag.

FIG. 1 is a diagram illustrating an area in which each action provided by the CDS obtains information, and shows an area in which actions affect the action of obtaining information about content in a file system.

Typically, calling the Browse action repeatedly with a Flag called BrowseDirectChildren gives you the opportunity to search from the root to the last object in every tree. However, not all CPs repeatedly request the Browse action to obtain information and store it in the CP.

For the Search action, you need to search all directories around Root to get objects and information related to a specific property. However, since the Search action is not defined as a required action in CDS, a call to the Search action can always obtain information related to a specific attribute in all directories under the root, or a DB must be created for it. I can't guarantee it.

In the present invention, as shown in FIG. 2, four steps are used to sequentially complete the DB table.

The media server examines all objects, such as directories and files shared when the media server first starts, and collects only the most basic information. In other words, the media server generates information that can be created directly with the file name itself at the beginning of startup. However, the information that needs to be retrieved inside the file is generated when the CDS action is called. Each Container and Item have a title (dc: title) and a class (upnp: class) as necessary elements. Such information is defined as Meta information of level 1.

If level 1 information is present, you can see what objects are currently in the CDS. However, in order for the user to select a desired object through the user interface (UI) of the CP, additional information about the objects such as the size of the object, the creator, the creation time, and the number of objects is needed. It is called level 2 information. Level 2 information is information obtained when a Browse action is called with a BrowseDirectChildren Flag centered on a specific directory, and is information about Objects included in area 2 of FIG. All information needed to be presented in the UI must be obtained.

Sorting or searching all objects under a given container or objects directly under a given container based on a predetermined attribute, for example, object creation time, size, and class. Occurs. In this case, the objects sorted or searched with a predetermined attribute and information about the same are referred to as level 3 information. Level 3 information is information about Objects included in region 1 or region 2 of FIG.

When calling the Browse action with the unique identifier of a specific container as the value of the input variable objectID, the BrowseDirectChildren Flag as the value of the input variable BrowseFlag, and the specified property as the value of the input variable SortCriteria, the Containers and Items inside the specific Container Information of level 3 sorted according to the predetermined attribute is obtained.

Level 3 for Containers and Items having the predetermined search attribute among the Containers and Items in the specific Container, even when a Search action is invoked with the unique identifier of the specific Container as the input variable objectID and the predetermined search attribute as the input variable. Obtain information of.

CDS, on the other hand, does not provide sorting or searching for all attributes. Therefore, the CP must first identify attributes that can be sorted or searched through the GetSortCapabilities and GetSearchCapabilities commands. In addition, the media server manages information on the sorted or retrieved results based on the sorted or retrieved predetermined attribute and the predetermined Container.

The time to get all the information you want from the CDS is to call the Browse action with the BrowseMetaData Flag. By calling the Browse action with the BrowseMetaData Flag, you get all the information that the Object has, for example, information about Codec, resolution, bit rate, playback time, and so on. Information about an object in area 3 of 1.

Because every level of information needs to be different, you need to decide what level of information to get when a particular action is called. Level 1, Level 2, and Level 4 are configured such that no effort is made to obtain the same information when information of the level is obtained.

In the case of level 3, since the information to be obtained is different depending on the requested field, that is, the container and attribute requested to be searched or sorted, first check whether there is a level 3 information that matches the field to be searched or sorted, Only generate level 3 information for that field.

In FIG. 4, the above description is expressed through an operation flowchart.

If the media server is running, check if the created DB exists. If there is no DB, execute the Browse action repeatedly to create level 1 information and add it to the DB. After waiting for the CDS action to be called from the CP or renderer, when the CDS action is called, branching is generated according to the CDS action type to generate information of the corresponding level.

When a Browse action with a BrowseDirectChildren Flag is called for a given container, it checks whether the level 2 information for the given container exists and, if it does not exist, creates the level 2 information and adds it to the DB, and adds the resulting XML to the Browse action. Send to the calling CP or renderer.

When a Browse action with a BrowseMetaData Flag is called for a given container or item, check whether the level 4 information for the given container or item exists, and if not, create the corresponding level 4 information and add it to the DB and add the resulting XML. Send the Browse action to the CP or renderer that called it.

When a Browse action having a sort variable of BrowseDirectChildren Flag and a predetermined property is called for a predetermined container or a Search action having a search variable of a predetermined property is called for a predetermined container, level 3 information on the predetermined container and a predetermined property exists. If it does not exist, the level 3 information is generated and added to the DB, and the resulting XML is transmitted to the CP or renderer that called the Browse or Search action.

If the corresponding level of information already exists for the action call, the resulting XML is not sent to the DB but the resulting XML is sent to the CP or renderer that called the action.

As described above, preferred embodiments of the present invention have been disclosed for the purpose of illustration, and those skilled in the art can improve, change, and further various embodiments within the technical spirit and the technical scope of the present invention disclosed in the appended claims. Replacement or addition may be possible.

According to the present invention, an implementer who implements CDS using a DB can solve a problem that it takes a long time to create a DB initially, and generate a DB by generating different kinds of information depending on when a UPnP action is called. It is effective in not recognizing the problem of the time it takes.

Claims (19)

Step 1 of generating information that can be made to the name of the object in the DB; And Checking whether the response information for the called action exists in the DB; And And generating, in the DB, response information about the called action when the response information does not exist. The method of claim 1, The media server is a DB generation method in the media server, characterized in that the server for providing a CDS. The method of claim 1, Wherein the step 1 is performed when the media server starts DB creation method in the media server. The method of claim 1, The method of claim 1, wherein the information on all the shared objects is generated. The method of claim 4, wherein And generating information on all shared objects in a DB by repeatedly calling the Browse action having a BrowseDirectChildren flag for all the trees under the root. The method of claim 1, The information generated in step 1 includes the identifier, title, and class of the object. delete The method of claim 1, The response information on the action is classified according to the called action and stored in the DB. The method of claim 8, The action includes a Browse action and a Search action. The method of claim 8, The response information on the action is stored in the DB as a different item according to the value of the input variable included in the called action, DB creation method in the media server. The method of claim 10, And checking whether the response information for the called action exists in the DB based on values of the called action and input variables of the called action. The method of claim 10, The response information for the Browse action is stored in the DB according to the values of ObjectID and BrowseFlag, which are input variables, in the DB. The method of claim 12, The response information of the Browse action is a value of the BrowseFlag input variable and is stored in a DB classified according to BrowseDirectChildren and BrowseMetaData. The method of claim 10, The response information for the Browse action is stored in the DB as different items according to the values of ObjectID and SortCriteria as input variables. The method of claim 14, And a value for SortCriteria that can be supported by the media server's CDS is provided through a GetSortCapabilities action. The method of claim 10, The response information of the search action is stored in the DB as different items according to the input variable ObjectID and the value of the search variable. The method of claim 16, And a value for a search variable that can be supported by the media server's CDS is provided through a GetSearchCapabilities action. The method of claim 10, The response information for the Browse action, in which the unique identifier of the specific container and the BrowseDirectChildren are the values of the ObjectID input variable and the BrowseFlag input variable, respectively, includes the number of objects included in the specific container, the size of each object, the creation time, and the creator. DB creation method in the media server, characterized in that. The method of claim 10, The response information for the Browse action, in which the unique identifier of the Item related to the AV media data and the BrowseMetaData are the values of the ObjectID input variable and the BrowseFlag input variable, respectively, includes the codec type, version, resolution, bit rate, and playback time of the item. DB creation method in the media server, characterized in that the.

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