Information processing device, information processing method, and computer program

Technical Field

0001The present invention relates to an information processing apparatus and an information processing method, and a computer program. More specifically, the present invention relates to an information processing apparatus and an information processing method, and a computer program, in which in a configuration executing communications between devices connected to a network such as a home network, details of metadata as attribute information of contents that a content providing server has can be provided to a client, and on the client side, the update of the metadata or a more proper content acquisition and reproduction processing based on the meta data is enabled.

Background Art

0002As a data communication network becomes more and more popular today, a so-called home network where electrical home appliances, computers, and other peripheral units are networked to enable communication among them is becoming widely used in the home. A home network, which allows communication among networked devices to share the data processing function and to transmit and receive contents among them, provides the user with convenience and comfort. It is expected that a home network will become more widely used in future.

0003As a protocol suitable for the configuration of such a home network, there is known Universal Plug and Play (UPnP). Universal Plug and Play (UPnP) allows the user to easily build a network without complicated operations and allows the user on a networked device to receive the services provided by the connected devices without difficult operations and settings. Another advantages with UPnP are that it does not depend on the OS (Operating System) on a device and that devices can be added easily.

0004Under UPnP, a definition file conforming to XML (eXtensible Markup Language) is exchanged among devices for mutual recognition. The overview of UPnP is as follows: <ol id="ol0001" compact="compact"><li>(1) Addressing processing for acquiring its own device ID such as an IP address</li><li>(2) Discovery processing for searching for the devices in the network and, upon receiving responses from the devices, acquiring information, such as the device type and the function, included in the responses.</li><li>(3) Service request processing for requesting a device to provide a service based on the information acquired by the discovery processing</li></ol>

0005By executing the processing procedure described above, the services can be provided and received by applying devices connected to the network. A device newly connected to a network can perform the addressing processing described above to acquire the device ID, perform the discovery processing to acquire information on other devices connected to the network and, based on the acquired information, issue a service request to the other devices.

0006For example, when a user wants to reproduce a content, such as music data and image data stored in a server, on the client side device, the client side transmits an acquisition request to the server to transmit content information stored in the server, for example, various types of content attribute information such as the title or the artist name of a tune or a movie, data compression mode information (ATRAC: adaptive transform acoustic coding, MPEG: moving picture experts group, etc.) and, as necessary, copyright information. This attribute information is called metadata or meta information.

0007In response to the request from the client, the server transmits metadata (attribute information) of the content, owned by the server, to the client. Based on the metadata acquired from the server, the content information is displayed on a display of the client device according to a predetermined display program. For example, a tune list composed of artist names and titles is displayed on the display. Based on the display information, the user checks or selects a content to be reproduced and transmits a content transmission request to the server. The server receives the content request from the client and, according to the received request, transmits the content to the client, and the client side reproduces the received content.

0008In this way, a content stored in the server in the home network can be accessed from other devices connected to the network. For example, a device connected based on the UPnP connection that is a simple device connection structure described above can acquire a content. When the content is movie data or music data, a TV set or a player connected as a network connection device enables the user to watch a movie or listen to music.

0009However, the metadata transmitted and received between devices defined in UPnP, for example, between a server and a client, is uniform, so that in devices having various functions, some metadata received from the server may be insufficient.

0010For example, in the metadata received from the server, there may exist data which allows update processing such as rewrite, deletion and addition. In a case where, for example, a content list is displayed on the client device based on the metadata received from the server, under the existing UPnP, the transmission processing of data for judging which data is allowed to be rewritten, or which data can be subjected to delete and addition processing is not performed. Therefore, the user is required to perform try-and-error type processing in which the user actually tries executing data input in each data field to thereby execute metadata update processing.

0011As related art disclosed relating to the processing such as rewrite and addition of the metadata, for example, Patent Document 1 (<patcit id="pcit0001" dnum="JP2001292413A"><text>Japanese Published Application Publication No. 2001-292413</text></patcit>) can be cited. In Patent Document 1, there is described a structure in which metadata is written every working step in an image processing system gathering, editing/processing, and storing video/audio in a production company of a news program or the like. For example, while an outside broadcast van is moving to a news coverage site, metadata considered in a planning step is transmitted from a data managing apparatus at a broadcast station to an image pick-up apparatus at the news coverage site, and in a coverage step, metadata automatically generated, in addition to the metadata transmitted from the broadcast station, is recorded on a recording medium. In this manner, there is shown a structure which enables writing processing of various types of metadata in respective steps in a recording and reproducing apparatus, editing apparatus or the like. However, in this related art, there is not shown any means clearly indicating a range in which the update of the metadata, such as rewrite, addition, deletion allowed in respective steps or an apparatus, and the like, is enabled.

0012Furthermore, the metadata includes various data items such as a title, playing time, and data recording date and time, and a data mode in which input is enabled is defined for each data item; for example, only text data, only numeric data or only integer data can be inputted. In addition, in the case of the numeric data, a range of values that can be inputted may be defined. In the case of the text data, the number of input characters and the like may be defined. However, in the existing UPnP, since notification processing of the data mode in which input is enabled or the like is not performed between the devices at the time of transmitting and receiving the metadata, the try-and-error type processing is needed as in the foregoing.

0013Moreover, with respect to the server providing the content to the client, a server, such as an image data providing server and an audio data providing server, is often provided for each content that the server can provide. These respective servers own the contents in different data modes. For example, ATRAC3, ATRAC3plus, MPEG1, MPEG2, MPEG4 or the like are exemplified.

0014Although the client side can acquire the types of contents that the server owns in the discovery processing in UPnP, means for acquiring the details of the data modes is insufficient. Even if it is notified that the data is MPEG data, notification processing of the details including whether it is MPEG 2 or MPEG4 is insufficient, which disadvantageously results in an improper data selection or data transmission request by the user on the client side.

0015<patcit id="pcit0002" dnum="US20030004951A"><text>US 2003/0004951</text></patcit> discloses an automated client-server data validation system.

0016Document "<nplcit id="ncit0001" npl-type="s"><text>ContentDirectory:1 Service Template Version 1.01", DEBIQUE K</text></nplcit> ET AL, discloses the specification for ContentDirectory used for sharing content items in home networks.

0017Document "<nplcit id="ncit0002" npl-type="s"><text>Streaming support in an advanced multimedia infrastructure for the WWW", ROUSSEAU F</text></nplcit> ET AL, discloses an architecture for managing multiple media streams included in temporal HTML documents, including generic services for negotiating media streams on servers, controlling their delivery, adapting their characteristics to varying network and host conditions.

Summary of the Invention

0018Particular and preferred aspects of the present invention are set out in the appended claims.

Brief Description of Drawings

0019<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Fig. 1</figref> is a diagram of a network configuration example to which the present invention can be applied.</li><li><figref idref="f0002">Fig. 2</figref> is a diagram for explaining a configuration example of a network connection device.</li><li><figref idref="f0003">Fig. 3</figref> is a diagram for explaining a processing sequence between a server and a client in content data reproduction processing.</li><li><figref idref="f0004">Fig. 4</figref> is a diagram for explaining a processing sequence between the server and the client in property-information-update processing.</li><li><figref idref="f0005">Fig. 5</figref> is a diagram for explaining an example of XML data structure composed of property information transmitted from the server to the client.</li><li><figref idref="f0006">Fig. 6</figref> is a diagram for explaining a structure of the property information composing metadata which is set corresponding to content data.</li><li><figref idref="f0007">Fig. 7</figref> is a diagram illustrating an example of a content information list displayed on a display based on XML data composed of property information transmitted from the server to the client.</li><li><figref idref="f0008">Fig. 8</figref> is a diagram showing a flowchart for explaining a processing procedure of a client apparatus in data update processing of the property information transmitted from the server to the client.</li><li><figref idref="f0009">Fig. 9</figref> is a diagram for explaining classes utilizable as designation information of the property information to be transmitted to the server.</li><li><figref idref="f0010">Fig. 10</figref> is a diagram showing an example of the property information transmitted from the server to the client.</li><li><figref idref="f0011">Fig. 11</figref> is a diagram showing allowed values of codec in the property information.</li><li><figref idref="f0012">Fig. 12</figref> is a diagram for a processing sequence between the server and the client in reproduction-data-designation processing based on the property information.</li><li><figref idref="f0013">Fig. 13</figref> is a block diagram for explaining a processing function of the server.</li><li><figref idref="f0014">Fig. 14</figref> is a block diagram for explaining a processing function of the client.</li></ul>

Best Mode for Carrying out the Invention

0020Hereinafter, referring to the drawings, details of an information processing apparatus and an information processing method, and a computer program of the present invention are described.

[System Overview]

0021First, with reference to <figref idref="f0001">FIG. 1</figref>, the following describes an example of a network configuration to which the present invention can be applied. <figref idref="f0001">FIG. 1</figref> shows a configuration, such as a home network configuration, in which a server 101 which executes processing in response to processing requests from various client apparatuses and a PC 121, a monitor 122, a mobile phone 123, a player 124, and a PDA 125 as the client apparatus that issue processing requests to the server 101 are connected via a network 100. Various other electronic devices and electrical household appliances can also be connected as a client apparatus.

0022Processing executed by the server 101 in response to a request from a client includes the provision of contents stored in storage means such as a hard disc owned by the server 101 or the provision of data processing services through the execution of an application program executable by the server. Although the server 101 and the client apparatus are shown as two separate devices in <figref idref="f0001">FIG. 1</figref>, only a device that provides a service in response to a request from a client is shown as a server. Any client apparatus that provides its own data processing service to other clients can provide the function as a server. Therefore, the client apparatus connected to the network shown in <figref idref="f0001">FIG. 1</figref> can also act as a server.

0023The network 100 is a wired or wireless network, and the connected devices transmit and receive communication packets such as Ethernet (registered trademark) frames via the network 100. That is, a client issues a data processing request to the server 101 by transmitting an Ethernet frame with processing request information stored in a data portion of the frame, to the server 101. Upon receiving the processing request frame, the server 101 executes data processing, stores result data generated as a result of the data processing into the data portion of the communication packet as necessary, and transmits the packet to the client.

0024The devices connected to the network are, for example, devices conforming to Universal Plug and Play (UPnP). Therefore, devices can be added to and deleted from the network easily. A device newly connected to the network performs the following: <ol id="ol0002" compact="compact"><li>(1) Addressing processing for acquiring its own device ID such as an IP address</li><li>(2) Discovery processing for searching for devices in the network and, upon receiving responses from the device, acquiring information, such as the device type and the function, included in the responses.</li><li>(3) Service request processing for requesting a device to provide a service based on the information acquired by the discovery processing</li></ol>

0025By executing the processing procedure described above, the services by applying devices connected to the network can be received.

0026With reference to <figref idref="f0002">FIG. 2</figref>, the following describes an example of the hardware configuration of a PC that is an example of an information processing apparatus composing the server and the client apparatus shown in <figref idref="f0001">FIG. 1</figref>.

0027A CPU (Central Processing Unit) 201 executes various types of processing according to the programs stored in a ROM (Read Only Memory) 202, an HDD 204 or the like to function as data processing means or communication control processing means. A RAM 203 stores programs to be executed by the CPU 201 as well as data as necessary. The CPU 201, ROM 202, RAM 203, and HDD 204 are interconnected via a bus 205.

0028An input/output interface 206 is connected to the bus 205. To this input/output interface 206 are connected an input unit 207, which is composed of a user-operated keyboard, switches, buttons, a mouse and the like, and an output unit 208 which is composed of an LCD, a CRT, and a speaker for presenting various types of information to a user. Also connected to this input/output interface 206 are a communication unit 209, which functions as data transmitting and receiving means, and a drive 210 to which a removable recording medium 211 such as a magnetic disc, an optical disc, an magnetic optical disc, or a semiconductor memory can be attached and which reads data from and writes data to the removable recording medium 211.

0029The configuration shown in <figref idref="f0002">FIG. 2</figref> is an example of the server, or the personal computer (PC), that is an example of a device connected to the network shown in <figref idref="f0001">FIG. 1</figref>. The devices connected to the network are not limited to a PC but, as shown in <figref idref="f0001">FIG. 1</figref>, can include a portable communication terminal such as a mobile phone and a PDA and various electronic devices and an information processing apparatus such as a player and a display. Therefore, a device can have its own hardware configuration for executing processing according to the hardware.

[Metadata]

0030Next, the following describes metadata owned by the server in which contents to be provided to clients are stored. The server has attribute information as metadata, wherein the attribute information corresponds to the contents such as image data on still images and moving images and audio data such as music stored in its storage unit.

0031The contents such as image data like still images and moving images and audio data like- music owned by the server are called collectively as AV contents. The AV contents are managed by a hierarchically structured content directory in the server.

0032The content directory has a hierarchical structure composed of an individual AV content or folders which contains a plurality of AV contents. An element of the content directory, that is, each AV content or folder containing a plurality of AV contents is called an object. An object is a generic term for a data unit processed by the server and, in addition to an individual AV content or folder containing a plurality of AV contents, there are various objects.

0033The minimum unit of an AV content, such as one piece of music data, one piece of moving image data, or one piece of still image data, is called an item.

0034Objects are classified into classes, for example, music (Audio), video (Video), and photograph (Photo), according to the types, and each object is labeled as a class. A client can designate a specific class to search for only objects belonging to a specific classification and execute it. In the server, classes are managed also in a hierarchical structure with subclasses under each class.

0035Metadata is composed of various types of management information including attribute information corresponding to contents that the server has, class definition information, and hierarchical information composing the content directory. Metadata, which is the attribute information on a content defined corresponding to each object, includes various types of information such as an identifier (ID), data size, resource information, title, artist name, and copyright information of the content. Each piece of information included in metadata is called a property. What properties the metadata should have are previously defined for each of the classes described above such as music (Audio), video (Video), and photograph (Photo).

[Processing by Client Based on Acquired Property Information]

0036For example, a client who wants to reproduce a content can transmit a content request to the server, receive the requested content from the server, and reproduce the received content. With reference to <figref idref="f0003">FIG. 3</figref>, the following describes a general content reproduction procedure. First, in step S11, the client transmits an acquisition request for content information owned by the server. In step S12, in response to the request from the client, the server uses XML (eXtensible Markup Language) data to generate content information, such as titles and artist names, based on the metadata corresponding to the contents, and then transmits the generated information to the client.

0037In step S13, the client displays the content information on the display according to the received XML information. For example, in the case of music contents, a list of music titles, artist names, reproduction times and the like, corresponding to a plurality of music pieces owned by the server, is displayed.

0038Next, in step S14, the client on the client apparatus selects a tune to be received from the server for reproduction and transmits the content-designation information (for example, content ID) to the server. The server acquires the content from the storage means based on the received content designation information and transmits the content. In step S16, the client reproduces the content received from the server. If compressed according to ATRAC, MPEG or the like, the content is decompressed and then reproduced on the client side.

0039The usual content reproduction procedure is as described above. The client can acquire various types of content attribute information, that is, property information included in metadata corresponding to contents owned by the server. This property information includes rewritable items. Accordingly, the user can rewrite the content information displayed on the client device, for example, the data on the content list, based on the XML information received from the server, or can perform addition or deletion processing of the data.

(Editing of Property Information - not covered by the claims)

0040In the structure of the present invention, in response to a request for the content information from a user, that is, a client to a server, XML data including data editing information is generated and transmitted to the client. The data editing information is allowed for each piece of property information included in the metadata corresponding to a content, and more specifically, it is data update enable/disable information which is composed of whether or not rewrite processing, addition processing, or deletion processing of the property information is enabled, and input-allowed data values, for example, a type of input-allowed data format, an allowed numeric range and the like.

0041Based on the XML data composed of the property information received from the server, for each piece of property information, the client machine generates display information (UI: user interface) in which the user can identify the various types of editing information such as whether or not rewrite processing or the like is enabled, the type of input-allowed data, and the numeric range of the data that can be inputted, and presents it as display information such as a content list on the display. Accordingly, the user can perform proper data update, based on the content information such as the content list in which the editing information can be identified.

0042The following describes a series of sequence in which the property information included in the metadata as attribute information of contents is transmitted from the server to the client, and the client machine displays the content information based on the received information to execute the data update processing.

0043<figref idref="f0004">Fig. 4</figref> shows a series of processing sequence between the server and the client in the update processing of the property information.

0044First, in step S21, the client requests content information owned by the server. Here, a command [X_GETSchema] is transmitted to the server. The command [X_GETSchema] is an interpretable command in the devices configuring the system of the present invention, and the server that has received this command generates XML data based on the property information composing the metadata corresponding to various objects such as contents according to the request.

0045The client can designate on which object, that is, on which type of contents the property information is acquired. The client designates one class from the above-described classes such as music (Audio), video (Video) and photograph (Photo), for example, and executes an acquisition request for the property information of the object included in the designated class. In this case, a class name is added to the command [X_GETSchema] and the command is transmitted to the server.

0046Upon receiving the acquisition request for the property information from the client, the server acquires, for example, the corresponding metadata of the contents corresponding to the designated class from the storage means, and based on the acquired metadata, generates the XML data including the property information to be transmitted to the client. The server transmits the generated XML data to the client in step S22.

0047In the structure of the present invention, in response to the request for the content information from the user, that is, the client to the server, for each piece of property information included in the metadata corresponding to the contents, the server generates the XML data including the data editing information as various types of data update enable/disable information composed of whether or not the rewrite processing, addition, deletion or the like is enabled, and input-allowed data format, data values that can be inputted and the like, and then transmits the XML data to the client.

0048Based on the XML data composed of the property information received from the server, for each piece of the property information, the client machine generates display screen (UI: user interface) on which the user can identify whether or not the rewrite processing, addition, deletion or the like is enabled, the input-allowed data format, and the data values that can be inputted and the like, and presents it on the display as the content information. Accordingly, displaying the content information such as a content list on the display allows the user to perform proper data update.

0049<figref idref="f0005">Fig. 5</figref> shows an example of XML data composed of a plurality of pieces of property information included in metadata corresponding to a content, which is transmitted from the server to the client. In the structure of <figref idref="f0005">Fig. 5</figref>, each of the data portions 301, 302, 303, 304 is the XML data relevant to each piece of the property information composing the metadata.

0050For example, the data portion 301 has the following structure. <pre listing-type="program-listing"> <av:PropertyInfo> <av:PropertyName>dc:title</av:PropertyName> <av:MinOccurred>1</av:MinOccurred> <av:MaxOccurred>1</av:MaxOccurred> <av:OperationCode>rcw</av:OperationCode> </av:PropertyInfo></pre>

0051The detailed meaning of the descriptive data of the XML data is shown in <figref idref="f0006">Fig.6</figref>. <u><av</u>:PropertyInfo> indicates the start of the property information. <<u>av:</u>PropertyName>dc:title</<u>av:</u>PropertyName> indicates that the name of the property is a title (title). <<u>av:</u>MinOccurred>1</<u>av:</u>MinOccurred> indicates an existing minimum value of this property information. <<u>av:</u>MaxOccurred>1</<u>av:</u>MaxOccurred> indicates an existing maximum value of this property information. The foregoing case indicates that the property [title] has one minimum and one maximum, that is, there surely exists one.

0052<<u>av:</u>OperationCode>rcw</<u>av:</u>OperationCode> is a processing code including the editing information of this property and has the following meaning.

0053r...Exist in an object returned from the server, such as Browse and Search c...Enabled to be designated at the time of CreateObject w...Enabled to be rewritten by UpdateObject a...Enabled to be increased by UpdateObject d...Enabled to be deleted by UpdateObject s...Enabled to be included in SortCriteria by Browse/Search

0054The above-described property [title] is <<u>av:</u>OperationCode>rcw</<u>av:</u>OperationCode>, in which the setting of [w] is found. It is understandable that this property is data that can be rewritten by the user in the update processing (UpdateObject). </<u>av:</u>PropertyInfo> indicates the end of the property information.

0055The data portion 302 of <figref idref="f0005">Fig. 5</figref> has the following structure. <pre listing-type="program-listing"> <av:PropertyInfo> <av:PropertyName>upnp:artist</av:PropertyName> <av:MinOccurred>0</av:MinOccurred> <av:MaxOccurred>1</av:MaxOccurred> <av:OperationCode>rcwad</av:OperationCode> </av:PropertyInfo></pre>

0056In the above-described property information, the property name is [artist (artist)], which indicates it is property information of an artist. In <<u>av:</u>OperationCode>rcwad</<u>av:</u>OperationCode>, [r, c, w, a, d] is set, which indicates this is data that can be rewritten by the user in the update processing (UpdataObject), can be increased (a), and can be deleted (d) .

0057The data portion 303 of <figref idref="f0005">Fig. 5</figref> has the following structure. <pre listing-type="program-listing"> <av:PropertyInfo> <av:PropertyName>av:recordQualityLevel</av:PropertyName > <av:MinOccurred>1</av:MinOccurred> <av:MaxOccurred>1</av:MaxOccurred> <av:OperationCode>rcw</av:OperationCode> <av:AllowedValueRange> <av:Minimum>3</av:Minimum> <av:Maximum>5</av:Maximum> <av:Step>1</av:Step> </av:AllowedValueRange> </av:PropertyInfo></pre>

0058The above-described data indicates a property [record quality level]. In this structure, the following is data indicating a range of values that are allowed in the property [record quality level] and its step (increment). <pre listing-type="program-listing"> <av:AllowedValueRange> <av:Minimum>3</av:Minimum> <av:Maximum>5</av:Maximum> <av:Step>1</av:Step> </av:AllowedValueRange></pre>

0059That is, for the property [record quality level], the values of 3 to 5 can be set and the step is 1. Accordingly, it is understandable that the respective value of 3, 4, and 5 can be set as [record quality level] .

0060The data portion 304 of <figref idref="f0005">Fig. 5</figref> has the following data structure. <pre listing-type="program-listing"> <av:PropertyInfo> <av:PropertyName>av:recordStatus</av:PropertyName> <av:MinOccurred>1</av:MinOccurred> <av:MaxOccurred>1</av:MaxOccurred> <av:OperationCode>r</av:OperationCode> <av:AllowedValueList> <av:AllowedValue>NotYet</av:AllowedValue> <av:AllowedValue>Timed</av:AllowedValue> <av:AllowedValue>Recording</av:AllowedValue> <av:AllowedValue>Recorded</av:AllowedValue> </av:AllowedValueList> </av:PropertyInfo></pre>

0061The above-described data is data regarding a property [record status (recordStatus)]. In this structure, the following is list data of values that are allowed in the property [record status (recordStatus)]. <pre listing-type="program-listing"> <av:AllowedValueList> <av:AllowedValue>NotYet</av:AllowedValue> <av:AllowedValue>Timed</av:AllowedValue> <av:AllowedValue>Recording</av:AllowedValue> <av:AllowedValue>Recorded</av:AllowedValue> </av:AllowedValueList></pre>

0062It is understandable that four values of (NotYet), (Timed), (Recording) and (Recorded) are allowed in the property [record status (recordStatus)] as settable values.

0063In this manner, the property information transmitted from the server to the client includes modes in which the update processing is enabled, and the information of the settable values.

0064Back to <figref idref="f0004">Fig. 4</figref>, the description of the processing sequence between the server and the client is continued. When the server transmits the above-described XML data as shown in <figref idref="f0005">Fig. 5</figref>, for example, and the client receives it, the client machine displays a content information list based on the XML data, on the display of the client machine.

0065In the display processing of this content information list, the list display is executed, based on the modes in which the update processing is enabled and the information of settable values, which are set for each piece of the above-described property information. A display example of the content information list is shown in <figref idref="f0007">Fig 7</figref>.

0066By setting the display differently, for example, displaying a rewritable area in white and displaying a non-rewritable area in gray, the user can understand which field is rewritable. The example shown in <figref idref="f0007">Fig. 7</figref> is merely one example, and a structure in which by color display, fields that can be rewritten, added, and deleted are set in different colors may be employed. Furthermore, not only by color display but by various types of graphic processing, the respective fields may be set so that the editable modes of the respective fields can be identified.

0067For example, a field 351 as shown in <figref idref="f0007">Fig. 7</figref> is a data field of rewritable property information, and a field 352 is a data field of property information which is not allowed to be rewritten. Furthermore, in a data field 353 of a property for which settable numeric values are defined, settable numeric data 1,2,3 are demonstrated, and further, for a field 354 in which the four values (NotYet), (Timed), (Recording), and (Recorded) are defined as settable values, display processing for displaying a structure in which the settable values are presented as a combo box is possible. This is executed in the client machine, based on the XML data received from the server (refer to <figref idref="f0005">Fig. 5</figref>).

0068The display processing mode of the content list shown in <figref idref="f0007">Fig. 7</figref> is one example, and various displays other than this display processing mode are possible. Note that the editing information corresponding to each piece of the property information received from the server, that is, various types of information such as whether or not rewrite is enabled, whether or not addition or deletion is enabled, the data format in which input is enabled, and settable values are displayed in a mode in which the user can identify them. This display processing allows the user to efficiently execute proper data update.

0069Back to the processing sequence between the server and the client in <figref idref="f0004">Fig. 4</figref>, the description is continued. In step S23, the client executes the content information display (for example, <figref idref="f0007">Fig. 7</figref>), based on the property information received from the server (XML data). As necessary, in each field, the data update such as the data rewrite, addition and deletion is executed.

0070Furthermore, in step S25, the property information including the updated data is transmitted to the server. The server stores the updated property information in its own storage unit. That is, the corresponding metadata of the content corresponding to the updated property information is overwritten with the updated property information to perform update processing of the metadata. In the server, the update processing is completed, and then, in step S26, an update-completion notification is transmitted to the client to thereby complete the property information update processing.

0071Acquisition processing and update processing procedure of the property information in the client apparatus is described, referring to a processing flow of <figref idref="f0008">Fig. 8</figref>.

0072In step Sill, the client apparatus performs an acquisition request for the property information to the server. As described above, this is executed as processing of transmitting the command [X_GETSchema], for example, with the class designation added, to the server.

0073In step S112, the client receives the property information from the server as the XML data, and in step S113, based on the received property information, the client generates the display information (UI) in which the user can identify the update enabled/disabled modes, that is, whether or not rewrite processing, addition processing, or deletion processing is enabled, an allowed data format, and allowable data values, and displays it on the display. The display information is, for example, the content list described with reference to <figref idref="f0007">Fig. 7</figref>.

0074The user, in step S114, the user executes the data update processing to the content information displayed on the display of the client apparatus, and in step S115, transmits the updated information to the server. When the update processing in the server is completed, in step S116, a response as an update-processing-completion notification (Ack) is received to finish the processing.

0075As described above, the structure of the present invention is such that for an individual element composing metadata as attribute information of a content, that is, for each piece of the property information, its allowed-editing information is added to XML data, and transmitted from the server to the client, and in the client apparatus, based on the received XML data, a content information list in which the user can identify an editing permitting mode for each piece of the property information is generated and displayed as the user interface. Therefore the user can efficiently and surely execute proper editing processing with respect to each piece of the property information.

(Reproduction-Content Designation Based on Acquired Property Information)

0076As described above, in the structure of the present invention, the detailed property information is transmitted from the server to the client. The above description is given, focusing on the editing processing of the property information in the client, and the client can execute more proper content reproduction processing by receiving the detailed property information from the server.

0077When acquiring properties composing metadata corresponding to contents, as described above, the client can designate a class of contents that the server has to thereby acquire the property information.

0078In the server, the classes are each managed in a hierarchal structure, and subclasses as child classes of one class can be set. For example, various classes are set as classes relating to music (Music). As the classes relating to music (Music), for example, classes as shown in <figref idref="f0009">Fig. 9</figref> are set.

0079As shown in <figref idref="f0009">Fig. 9</figref>, various classes such as tunes, albums, genres, album cabinets in each of which a plurality of albums are collected are set. The client designates these classes and transmits to the server, the above-described command [X_GETSchema] as a property information acquisition request, so that the property information of the contents corresponding to the designated class can be acquired.

0080The designation of the class allows the user to obtain information of what property can be treated in the class. Although not all objects in the designated class have common properties, in this case, the server returns only the common properties. For example, in a case where a subclass (1) of the designated class has properties (A) and (B), and a subclass (2) has properties A and C, the server returns only the property A which is common to both.

0081The client can also transmit, to the server, the command [X_GETSchema] as a property information acquisition request with no class designation. Upon receiving the [X_GETSchema] with no class designation, the server transmits listing information of the classes managed by the server to the client. This processing allows the client to acquire the class information managed by the server. In this manner, after acquiring the class information managed by the server, the client can transmit, to the server, the command [X_GETSchema] with a particular class designation, which enables the property information acquisition in which the class managed by the server is precisely designated.

0082As shown in <figref idref="f0009">Fig. 9</figref>, the classes are subjected to various classification, and the user can designate an arbitrary class to acquire the property information of the designated class.

0083Music contents and Image contents are stored in various modes in the server. That is, compressed data modes such as ATRAC3, ATRAC3plus, MPEG2, and MPEG4 are different depending on the stored contents. Also, the record quality, so-called record quality level of the contents is different.

0084Meanwhile, in the client apparatus, the data mode in which the data can be processed by its device is different. It is preferable that each of the clients receives the data with the highest quality which can be processed by itself and performs reproduction processing.

0085In the structure of the present invention, the property information transmitted from the server to the client also includes information regarding the data quality of the contents. The server generates content information including data mode information by which processing capability in the device on the client side can be determined and transmits the generated content information to the client.

0086The server stores the information regarding the data of a content as shown in <figref idref="f0010">Fig. 10</figref>, for example, as metadata corresponding to the content as property information, which is presented to the client in response to a property information acquisition request from the client.

0087<figref idref="f0010">Fig. 10</figref> is a diagram showing an example of a part of the property information presented to the client. Property name (Property Name), data type (Type) such as numeric values and letter strings, multiple (Multiple) indicating whether or not multiple existence is enabled, and property description (Property Description) are shown. Total size (total Size) indicates size-data of an original content. Container indicates an object as a folder storing contents. Total duration (total Duration) indicates a total time of the content. Record quality level (record Quality Level) is data indicating a quality level which is a record quality of the content. For example, integer values of 1 to 7 are allowed, and are set in such a manner that 3=2Mbps, 4=4Mbps, 5=8Mbps, etc.

0088Original file format (original File Format) indicates a format of the original content data before conversion. It is shown as MIMEType, for example. Original codec (Original Codec) indicates a codec as a coding data mode of the original content data before conversion.

0089Settable values as original codec (Original Codec) as a property, that is, allowed values (Allowed Value) are preset, as shown in <figref idref="f0011">Fig. 11</figref>. Namely, various setting allowed values such as MPEG1L3, ATRAC3, ATRAC3plus,··JPEG,··MPEG4V, which indicate various data compression processing modes, are defined in advance. The data compression processing modes corresponding to the respective allowed values (Allowed Value) are as shown in description (Description) of <figref idref="f0011">Fig. 11</figref>.

0090Back to <figref idref="f0010">Fig. 10</figref>, again the description of the property information is continued. Original resolution (original Resolution) is resolution information regarding original data of image data. Resource protocol information (res@protocol Info) is information regarding a file format of a resource. [res] indicates that it is resource information. The server can have information obtained by converting the original data in various modes, as resource data, aside from the original data. The data after conversion is resource data.

0091Resource codec (res@av:codec) is coding data mode information regarding the resource data, for which various setting allowed values such as MPEG1L3, ATRAC3, ATRAC3plus··JPEG,··MPEG4V indicating the data compression processing modes as shown in <figref idref="f0011">Fig. 11</figref>, are defined in advance. Resource size (res@size) indicates a size of the resource data.

0092The property information shown in <figref idref="f0010">Fig. 10</figref> is information that the server owns as attribution information corresponding to the content, and indicates a part of the information which can be provided to the client. Various types of content information other than those shown in this figure are provided from the server to the client according to the property information acquisition request from the client.

0093The client can receive and identify record quality level which is a data recording quality of a content that the client wants to reproduce, and details of codec information as coding modes, so that the client can select an optimal data mode in the client device to request the transmission. Therefore, reception and reproduction of optimal content data according to the client can be performed.

0094When the property information is transmitted from the server to the client, the client, based on the property information, identifies the optimal data mode for its own device according to the program stored in advance, and transmits content data transmission request in the identified data mode to the server.

0095A transmission and reception processing sequence of a content is described referring to <figref idref="f0012">Fig. 12</figref>. First, in step S31, the client requests content information owned by the server. As described above, the command [X_GETSchema] is transmitted to the server. The client designates one class from the above-described classes such as music (Audio), video (Vidoe), photograph (Photo) and executes an acquisition request for property information of objects included in the designated class. For example, the command [X_GETSchema] with a class name added is transmitted to the server.

0096Upon receiving the acquisition request for the property information from the client, the server acquires corresponding metadata of contents corresponding to the designated class, for example, from the storage means, and based on the acquired metadata, generates XML data including the property information to be transmitted to the client. Then, in step 32, the generated XML data is transmitted to the client.

0097In the structure of the present invention, in response to the request for content information from the user, that is, the client to the server, the server puts, into the property information, record quality level of the contents, and details of codec information as coding modes from metadata corresponding to the contents, and transmits the property information as XML data to the client. Specifically, the server generates the content information including data mode information by which processing capability in the device on the client side can be judged, that is, record quality level and codec information as coding modes as data mode information of the content data and transmits the generated content information to the client.

0098In step S33, based on the XML data composed of the property information received from the server, the client apparatus determines an optimal data mode in which the data can be reproduced as high quality data, for example, record quality level=3 codec=MPEG4 according to the codec of its own device, that is, a decoding processing function or the like. This determination processing of the transmission content data mode is automatically determined based on comparison between the property information corresponding to the contents received from the server and the function of its own device, according to the program stored in the client in advance.

0099However, a structure may be employed, in which the data mode information based on the property information is displayed on the display as the content information list described above with reference to <figref idref="f0007">Fig. 7</figref>, and the user selects a transmission content data mode, based on the content resource information.

0100In step S34, the determined content data mode information is transmitted from the client to the server, and the server, based on the received information, selects a resource content and, in step S35, transmits the content to the client. In step S36, the client executes the reproduction processing of the content received from the server.

0101In this manner, as the content information owned by the server, the client can receive the record quality level of the contents and the details of the codec information as codec modes, as the property information, so that optimal data selection suitable for the function of its own device, and high quality data reproduction can be realized.

[Functional Configurations of Server and Client]

0102The hardware configuration of the server and the client apparatus is as described above with reference to <figref idref="f0002">Fig. 2</figref>. The CPUs as control units execute the above-described various types of processing according to the programs stored in the respective storage units of the server and the client.

0103For the processing executed by the CPUs, for example, on the server side, the processing is such that according to a request from the client, the server acquires metadata corresponding to contents and generates XML data based on property information, and such that a content according to a requested data mode from the client is transmitted, etc. The processing on the client side is such that the client displays a content information list on the display based on the XML data composed of the property information received from the server. This processing includes generation processing of display information in which data editing information can be identified for each piece of the property information as component of the content information. Furthermore, the processing for determining a data mode of the content to be requested to the server based on the function of its own device and content resource information, and further the reproduction control processing of the received content and the like are executed.

0104Basically, the above-described processing is executed under control of the CPUs as the control units of the server and the client apparatus, and a functional configuration of the server and a functional configuration of the client required for the execution of the above-described processing are described with reference to <figref idref="f0013">Figs. 13</figref> and <figref idref="f0014">14</figref>.

0105<figref idref="f0013">Fig. 13</figref> is a block diagram showing a main functional configuration of the server. A packet sending and receiving unit 501 sends a packet to the client and receives a packet from the client. A packet generating and analyzing unit 502 performs generation processing of a send packet, and analysis processing of a receive packet. The processing includes address setting of the packet, address identification, data storage in a data portion, data acquisition processing from the data portion and the like.

0106A content storage unit 503 stores the contents owned by the server. The contents include original contents and content data obtained by performing data conversion for the original contents. A metadata storage unit 504 is a storage unit storing metadata as attribute information corresponding to the contents.

0107In the metadata storage unit 504, as described above, the property information composed of the metadata is stored and editing enable/disable information of each piece of property information, for example, the data editing information, such as information of whether or not rewrite is enabled, whether or not addition or deletion is enabled, etc. and input-allowed data format information, input-allowed data value information, etc. is included.

0108Furthermore, as described above, the property information indicating the data modes of the contents, that is, the content data modes such as the record quality level and the codec information is also included.

0109A property information acquiring unit 505, based on a property information acquisition request received from the client, for example, based on a packet with a class name added to the command [X_GETSchema], executes processing for taking out metadata corresponding to a designated class from the metadata storage unit 504.

0110An XML data generating unit 506 generates XLM data to be transmitted to the client, based on the metadata acquired by the property information acquiring unit 505. The XML data shown in <figref idref="f0005">Fig. 5</figref> is one example. A codec 507 executes coding processing and decoding processing of original content data. Data conversion, for example, based on ATRAC3 and MPEG4 is executed. Each of the servers has a different codec function and thus, according to the function, resource data that can be provided to the client is also different.

0111Next, the functional configuration of the client apparatus is described with reference to <figref idref="f0014">Fig. 14</figref>. A packet sending and receiving unit 601 sends a packet to the server and receives a packet from the server. A packet generating and analyzing unit 602 performs generation processing of a send packet, and analysis processing of a receive packet. The processing includes not only stored data analysis in the packet, but processing such as address setting of the packet, address identification, data storage for a data portion, data acquisition processing from the data portion.

0112A storage unit 603 stores the content included in the packet received from the server, and codec information of the client.

0113An output unit 604 includes a speaker and a display applied to content reproduction processing. The display is also used to output the content information list described above with reference to <figref idref="f0007">Fig. 7</figref>. An input unit 605 is, for example, a keyboard or other data input means for executing the input of editing information into the content information list, that is, rewrite, addition, and deletion processing of the property information.

0114An XML data analyzing unit 606 analyzes the XML data composed of the property information, which is received from the server, and based on the analyzed data, generates the content information list described above with reference to <figref idref="f0007">Fig. 7</figref> to execute processing for outputting the content information list to the display as the output unit.

0115A received data mode determining unit 607 executes processing for determining an optimal data mode to be received from the server, based on comparison between the property information received form the server, that is, the property information such as the record quality level of the contents and the codec information as coding modes, and the function of its own device.

0116A codec 608 executes decoding processing of the content data received from the server, or the like. For example, data conversion based on ATRAC3, MPEG4, for example, is executed. A structure may be employed, in which re-coding processing of the decoded data is executed and the processing for storing the re-coded data in the storage unit 603 is executed.

0117In a functional point of view, the server and the client have the respective functions as shown in <figref idref="f0013">Figs. 13</figref> and <figref idref="f0014">14</figref>, and execute the above-described processing. However, note that block diagrams shown in <figref idref="f0013">Figs. 13</figref> and <figref idref="f0014">14</figref> are block diagrams for explaining the functions, and that actually, various processing programs are executed under control of the CPUs in the configuration of the hardware such as the PC shown in <figref idref="f0002">Fig. 2</figref>.

0118With reference to particular examples, the present invention has been described in detail. However, it is obvious that those skilled in the art can make modifications and substitutions of the examples within the scope not departing from the gist of the present invention. That is, the present invention is disclosed merely in an exemplified form, which should not be limitedly construed. In order to judge the gist of the present invention, claims should be referred to.

0119The series of processing described in the specification can be executed by hardware or software, or a composite configuration of both. In the case where the processing by the software is executed, a program with a processing sequence recorded is installed in a memory in a computer, which is incorporated into dedicated hardware, and is executed by the computer, or the program can be installed in a general-purpose computer which can execute various types of processing and executed by this computer.

0120For example, the program can be prerecorded on a hard disc or ROM (Read Only Memory) as a recording medium. Alternatively, the program can be temporarily or permanently stored (recorded) on a removable recording medium such as a flexible disc, CD-ROM (compact Disc Read Only Memory), MO (Magneto optical) disc, DVD (Digital Versatile Disc), magnetic disc, and semiconductor memory. Such removable recording media can be provided as so-called package software.

0121The program can be not only installed from the above-described removable recording media to the computer, but the program can be wirelessly transferred from a download site to the computer, or wiredly transferred to the computer via a network such as LAN (Local Area Network) and the internet, and the computer can receive the program transferred in such a manner and install it in a recording medium such as an incorporated hard disc.

0122The various types of processing described in the specification are not only executed in chronological order according to the description, but may be executed in parallel or individually, depending on processing capability of the apparatus executing the processing, or as necessary. Furthermore, the system in the present specification has a logical assembly configuration of a plurality of devices, and the devices having the respective configuration are not necessarily within the same housing.

Industrial Applicability

0123As described above, according to the structure of the present invention, a server owning attribution information of contents is configured so as to extract metadata corresponding to the contents, based on the receipt of a content information acquisition request from a client, and to generate content information based on property information as component of the metadata, and is configured such that data editing information allowed by each piece of the property information is set for each property and transmitted to the client. Therefore, the client can efficiently and surely execute proper editing processing of the property information based on the received information.

0124Furthermore, according to the structure of the present invention, the client side receiving the content information from the server is configured so as to execute generation processing of display information in which the data editing information can be identified for each piece of the property information as component of the received content information and to display the display information on the display. Therefore, the client can efficiently and surely execute proper editing processing of the property information based on the received information.

0125Furthermore, according to the present invention, the structure is such that the server generates the content information including data mode information by which processing capability in the device on the client side can be judged, such as record quality level information indicating content recording quality or codec information indicating content coding modes, as the data mode information of the content data which can be transmitted from the server to the client, and that the content information is transmitted to the client. Therefore, the client can efficiently execute proper content selection processing based on the received information.

0126Furthermore, according to the present invention, the structure is such that the metadata as the content attribute information managed on the server side is managed based on class set as content classification. Therefore, acquisition processing of the property information with class designation from the client side is enabled, and thus, various classes such as tunes, albums, genres and album cabinets in each of which a plurality of albums are collected can be designated to acquire the property information.