JP2005117236A - Network apparatus and information request method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a user to receive provision of object digital contents with a proper format without the need for requesting the user to perform judgment and operations with even a format of the digital contents taken into consideration. <P>SOLUTION: When the user requests provision of the digital contents, the user uses a control section 250 to form a provision request instructing even the format of the digital contents whose provision is requested on the basis of information denoting the priority of formats in a priority ranking table formed in an EEPROM 254, and transmits the provision request to a server apparatus via a network by way of a communication section 202 and a connection terminal 201. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is, for example, an apparatus connected to a WAN (Wide Area Network) and a LAN (Local Area Network) and capable of receiving various provision information (digital content) such as music data and video data, and the apparatus Relates to a method for requesting provision of information.

  As the Internet connection environment in the home becomes broadband, an environment where a distribution service of provided information (digital content) including video and music can be used is being prepared. On the other hand, for the purpose of sharing an Internet connection by a personal computer, home networks such as a wireless LAN are widely used, and the environment for using digital contents is spreading.

  In addition, abundant digital contents that can be used through a CD (Compact Disc) player, an MD (Mini Disc) player, a liquid crystal television, a hard disk recorder, a digital camera, a digital video camera, and the like have come to exist in the home. . These digital contents can be used not only for the above-mentioned single device designed for the content, but also for other personal computers connected to the network, AV (Audio / Video) devices, PDA (Personal Digital Assistant) ), It is expected that there will be a demand for mutual use in consumer network devices such as mobile phone terminals.

  Thus, in a network system to which various network devices are connected, digital contents of various recording formats are handled. For example, regarding music data, the recording format of music data recorded on a CD is generally LPCM (Linear Pulse Code Modulation), and the recording format of music data recorded on an MD is ATRAC (Adaptive Transform Acoustic Coding) method. In addition, the recording format of music data distributed through the Internet or the like is often MP3 (MPEG-1 Audio Layer 3). In addition, there are various recording formats for still image data, moving image data, and the like as in the case of music data.

  For this reason, in each network device, how to handle digital contents of different formats often differs for each network device. For example, some personal computers that are also used as server devices can record digital content provided in the same format as provided.

  In other words, LPCM format music data from a CD is recorded on the hard disk in the LPCM format, ATRAC format music data from the MD is recorded on the hard disk in the ATRAC format, or MP3 format music acquired through the Internet. Some data can be recorded directly on the hard disk.

  Also, in network devices used as server devices, connectable client devices are assumed, and digital contents in various formats are converted into formats that can be easily received by the client devices in consideration of the capabilities of connectable client devices. Some of them are recorded on the hard disk of the server device. In this case, it is possible to reduce the types of formats to be supported by the server device and reduce the operation verification cost and the manufacturing cost.

  In Patent Document 1 described later, when digital content is recorded on a recording medium of an information providing device corresponding to a server device, the digital content is recorded in a predetermined format, and information corresponding to a client device is recorded. When providing digital content in response to a request from a terminal device, a technique for converting and providing digital content so as to be in a format corresponding to a format ID included in application information from an information terminal device is disclosed. ing.

  In the case of the technology disclosed in Patent Document 1, the information providing apparatus, for example, converts the provided digital content as it is or into a predetermined format when the digital content is taken into itself. Be able to capture. On the other hand, the information terminal device can reliably receive digital content in a format that can be decoded by the information terminal device.

In addition, said patent document is as showing below.
JP 2002-63385 A

  By the way, in each network device that can be connected to a network and used, it is desirable to be able to handle digital contents in a plurality of formats in order to ensure flexibility of the network and improve user convenience. In other words, it is desirable that the server device be able to transmit a plurality of digital contents of different formats and answer requests from various client devices connected to the network.

  However, as described above, when the server device can transmit a plurality of digital contents of different formats, the client device requests the server device to provide the desired digital contents in the desired format. There must be. Therefore, the client device must instruct the server device also about the format of the digital content.

  In this case, if there is one type of format that can be supported by the client device, the format to be instructed to the server device is uniquely determined, so there is no room for selecting the format used by the client device. However, if the client device can handle a plurality of different formats and can properly use them, the user of the client device must select which format of digital content is requested to be provided.

  For example, consider a case where music data is provided as digital content from a server device and this is streamed. In this case, if you want to perform high-quality audio playback, even if you request the provision of digital content formatted in LPCM, the network traffic is congested, and the available network bandwidth becomes narrow, When digital content is received and played back without interruption, for example, provision of digital content compressed with ATRAC or MP3 data may be requested.

  However, the user of the client device is more interested in content playback than what format the digital content is in. For this reason, information about the digital content is displayed for each format on the display screen of the client device, and the digital content having a different format can be selected, but the user also makes a selection considering the format of the digital content. This is impossible for users who do not understand the differences between formats.

  Also, in the network between the server device and the client device, if the bandwidth is used, for example, due to communication between different devices, and if sufficient bandwidth for communication in a specific format cannot be secured, ask the user for confirmation This is also complicated for the user, and it may be impossible for the user who does not understand the difference between formats to perform an appropriate confirmation operation.

  In addition, every time digital content is requested from the server device, it is complicated for the user to select the format of the digital content, and a simple network usage environment cannot be provided for the user. .

  In view of the above, when the requested information is requested, the user can be provided with the desired digital content in an appropriate format without requiring the user to make judgments and operations that also take into account the format of the digital content. It is an object of the present invention to provide an apparatus and a method that make it possible.

In order to solve the above problem, a network device according to claim 1 is provided.
A network device that receives distribution of provided information from a server device connected through a network,
Priority storage means for storing information indicating the priority order of the format specified for the provision information to be distributed from the server device;
Forming means for forming a provision request for provision information intended for formatting according to information indicating the priority order stored in the priority order storage means;
Transmitting means for transmitting the provision request formed by the forming means to the server device through the network;
Receiving means for receiving the provision information provided from the server device.

  According to the network device of the first aspect of the present invention, when the provision information is requested from the server device by the priority order storage means, the priority order of the format instructing the provision information to be provided ( Information indicating the priority order of the formats used for the provided information is stored and held.

  When requesting provision of provision information, provision that can also indicate the format of provision information that requires provision based on information indicating the priority order of formats stored in the priority order storage means The request is formed by the forming unit, which is transmitted to the network through the transmitting unit and transmitted to the server device.

  The server device transmits the provision information in the format corresponding to the provision request provided thereto, so that the receiving means receives the information and uses the provision information in the format according to the request. The

  Thus, at the time of requesting the provision request, the user can provide the provision information in a format according to a predetermined priority order without performing an operation such as designating a format for the provision information for which provision is requested. Be made available to request. Therefore, the user can receive the provision information in a format having a high priority without being aware of the format of the provision information.

A network device according to a second aspect of the present invention is the network device according to the first aspect,
Inquiry means for making an inquiry as to whether or not the format is compatible with the server device in order from the format with the highest priority stored in the priority storage means,
The forming means forms the provision request for the target provision information in the format in response to the response from the server device indicating that the format is compatible through the inquiry means.

  According to the network device of the second aspect, the inquiry unit confirms whether or not the server device has a compatible format in order from the highest priority. . Then, a provision request for provision information intended for a format that is first confirmed to be compatible is formed by the forming means and transmitted to the server device through the transmitting means.

  As a result, when the target provision information cannot be provided in a format with a high priority, the target provision information can be provided in a format with a low priority. Therefore, it is possible to minimize the state in which the target provision information cannot be provided. Moreover, users are not required to be aware of the format.

A network device according to a third aspect of the present invention is the network device according to the second aspect,
In order from the highest priority format stored in the priority storage means, the bandwidth confirmation means for confirming whether or not there is a sufficient bandwidth for transmitting provided information by the format,
The forming means is a format that has been confirmed by the bandwidth confirmation means to have a sufficient bandwidth and that it can be transmitted properly, and that is a format that can be supported through the inquiry means. The provision request for the target provision information in the format in which the response is accepted is formed.

  According to the network device of the third aspect of the present invention, the bandwidth confirmation unit confirms whether or not there is a bandwidth in the network in which the provided information can be properly transmitted in order from the highest priority. Then, it is a format in which it is confirmed that the bandwidth that can be properly transmitted is on the network, and if the server device can be handled by the inquiry means, the first provision of the format that can be confirmed is provided. An information provision request is formed by the forming unit, and is transmitted to the server device through the transmitting unit.

  As a result, the user can identify the format of the requested information to be provided without making the user aware of it, taking into account the state of the network that transmits the desired provided information and the function of the server device. It is possible to receive the delivery information provided as follows.

A network device according to a fourth aspect of the present invention is the network device according to the first aspect,
In order from the highest priority format stored in the priority storage means, the bandwidth confirmation means for confirming whether or not there is a sufficient bandwidth for transmitting provided information by the format,
The forming unit forms the request for providing the target provision information in a format in which it is confirmed that the band confirmation unit has a sufficient band and can be appropriately transmitted.

  According to the network device of the fourth aspect of the present invention, the bandwidth confirmation unit confirms whether or not there is a bandwidth in the network in which the provided information can be properly transmitted in order from the highest priority. Then, a provision request for provision information intended for a format in which it is confirmed that there is a band that can be properly transmitted on the network is formed by the forming means and transmitted to the server device through the transmitting means.

  As a result, it is possible to specify the format of the provision information requested to be provided without considering the user in consideration of the state of the network transmitting the desired provision information, and to distribute the provision information intended for the specified format. Will be able to receive.

  According to the present invention, the number of times of setting the format of the provided information is reduced, an appropriate format is automatically selected without being aware of the format of the provided information, and the provided information that is the purpose of the selected format Will be able to use it. Further, the format of the provided information can be stored in the storage means according to the user's preference and used.

  In addition, when the server device cannot provide the requested provision information in the requested format, it can re-request to provide the desired provision information in a format with a low priority. It is possible to minimize the fact that the provided information is not provided.

  In addition, since the provided information is provided in a format according to the use situation of the network that transmits the provided information, it can be expected that the interruption of sound is less likely to occur during streaming reproduction.

  Hereinafter, an embodiment of an apparatus and a method according to the present invention will be described with reference to the drawings. In the embodiment described below, a case where the present invention is applied to a network device used as a client device of a home LAN system called a home network system will be described as an example.

[First Embodiment]
FIG. 1 is a diagram for explaining an overview of a LAN system according to this embodiment. As shown in FIG. 1, the LAN system of this embodiment is configured by connecting a personal computer 1, a notebook personal computer 2, a set top box 3, a stereo system 4, and a PDA 5.

  The personal computer 1 and the notebook personal computer 2 have a hard disk drive and a function of connecting to an external network such as a modem, and connect to the Internet or the like to acquire and store various digital contents (provided information). Is something that can be done.

  In addition, the personal computer 1 and the notebook personal computer 2 have a connection end with an external device such as a CD player or an MD player, receive digital content from these external devices, record this on a hard disk, It can also be accumulated.

  The digital contents stored in the personal computer 1 and the notebook personal computer 2 include audio data such as music data of music, still image data, moving image data, AV data (synchronized image data and audio). Data), program data, text data, character data, and other various data.

  In FIG. 1, each of the set-top box 3, the stereo system 4, and the PDA 5 is a device that receives digital content from the personal computer 1 or the notebook personal computer 2 and reproduces it. Therefore, each of the set top box 3, the stereo system 4, and the PDA 5 is positioned as a client device when the personal computer 1 and the notebook personal computer 2 are used as server devices.

  A monitor receiver is connected to the set-top box 3, and broadcast program data (AV data) provided through a cable television network or the like is received and decoded to reproduce audio and video. The audio data, still image data, moving image data, AV data, etc. are provided from the personal computer 1 or the notebook personal computer 2 and can be reproduced.

  In addition, the stereo system 4 can receive audio data from the personal computer 1 or the notebook personal computer 2 and reproduce it. The PDA 5 can receive and reproduce audio data, still image data, moving image data, and AV data from the personal computer 1 or the notebook personal computer 2. Further, as shown in FIG. 1, audio data, still image data, moving image data, and AV data can be transmitted and received between the set top box 3 and the PDA 5.

  Although not shown in FIG. 1, audio data, still image data, moving image data, and AV data can be transmitted and received between the notebook personal computer 2 and the PDA 5, and the set top box 3 Between the stereo system 4 and the stereo system 4 and between the stereo system 4 and the PDA 5. Also, audio data, still image data, moving image data, AV data, etc. can be transmitted and received between the personal computer 1 and the notebook personal computer 2. Therefore, each of the personal computer 1 and the notebook personal computer 2 can also function as a client device.

  1 conceptually shows the configuration of the LAN system, the LAN system as shown in FIG. 1 can be formed using any topology of bus type, ring type, and star type. However, it is also possible to form by using a mixed form of each topology.

  In this embodiment, in the LAN system formed as shown in FIG. 1, for example, the stereo system 4 and the PDA 5 receive a packet distribution of digital contents such as music data from the personal computer 1, Consider the case of streaming playback. In this embodiment, a case where communication is performed using an IP (Internet Protocol) packet will be described as an example.

  FIG. 2 is a diagram for explaining streaming reproduction of digital content such as music data that can be performed in the LAN system of this embodiment. In FIG. 2, a server device 100 is a device such as the personal computer 1 or the notebook personal computer 2 shown in FIG. 1, and includes a recording medium such as a hard disk 103 that stores a large number of digital contents, and also from a client device. The communication unit 102 is provided for receiving the request and transmitting information corresponding to the received request.

  Further, as described above, the client device 200 is a device such as the set top box 3 or the PDA 5 that receives provision of digital content from the server device 100 such as the personal computer 1, and transmits a request to the server device 100. A communication unit 202 that receives information transmitted from the server device 100, a video signal processing unit 203 that processes video data (image data) from the server device 100, a display element 204 such as an LCD, and the server device 100. Are provided with an audio signal processing unit 205 and a speaker 206 for processing the audio data.

  Then, the client device 200 generates and transmits a request for providing the desired digital content to the server device 100 using an IP packet. When the requested digital content can be provided in response to the provision request from the client apparatus 200, the server apparatus 100 returns a response to that effect and is requested as indicated by a dotted arrow in FIG. The digital contents are sequentially transmitted by IP packet and provided to the requesting client apparatus 200.

  The client device 200 sequentially receives IP packets from the server device 100 through the communication unit 202, processes them by the video signal processing unit 203 and the audio signal processing unit 205, and reproduces them through the display unit 204 and the speaker 206. If the requested digital content cannot be provided for some reason, a response notifying that is sent from the server device 100 to the client device 200.

  Note that the IP packet used here is a unit of data transmitted / received on the Internet, and is formally called an IP datagram. Data communicated between application programs running on a so-called host such as a server device is transferred from the transmission host to an appropriate destination host using a unit of data called an “IP packet”. As described above, IP is an abbreviation for Internet Protocol. This Internet Protocol is a communication procedure (protocol) for dividing data from an upper layer into an appropriate size and for carrying a packet to a destination. .

  The IP packet includes (1) a part called a header part in which the IP address of the destination host and the IP address of the transmission host are written, and (2) a part called a data part in which application data is stored. The IP packet is transferred to the destination host based on the IP address information of the destination host written in the header part. In this way, data can be transmitted to the target device by using the IP packet.

  In addition, streaming playback of digital content provided by IP packets is a technology that enables sequential playback while transferring data over a network. There are a download type and a streaming type for transmitting multimedia contents such as audio and video over the Internet.

  The download type is a method in which the digital content itself is transferred as a file to the other party. Normally, the contents of the digital content cannot be reproduced until the download is completed. On the other hand, the streaming type has a mechanism that allows the receiving side to sequentially reproduce the data while buffering the data by sequentially sending the digital content data in pieces from the transmitting server side. For this reason, in addition to the so-called live (live) video real-time distribution that could not be realized with the download type, even when a low-speed line is used, real-time playback of a simple moving image can be performed.

  When the digital content to be reproduced is selected from the content data recorded on the hard disk of the server device 100, the content list (list of provided information) is provided from the server device 100. It is possible to display the content list on the display means and to select digital content through this.

  Next, basic configurations of the server device 100 and the client device 200 used in this embodiment will be described. First, the server apparatus 100 will be described.

  FIG. 3 is a block diagram for explaining the server apparatus 100 and shows a basic configuration of the personal computer 1 or a notebook personal computer that functions as the server apparatus 100, for example.

  As shown in FIG. 3, the server device 100 includes a connection end 101 for connecting to a LAN, a communication unit 102, a content storage hard disk 103 that stores a large number of digital contents (provided information), and various processes. The work hard disk 104 used as a work area, the control unit 150, the format conversion unit 161, the key interface (hereinafter abbreviated as key I / F) 162, the key operation unit 163, and an external interface (hereinafter referred to as “key interface”). It is abbreviated as an external I / F.) 164 and an external device connection end 165.

  The control unit 150 controls each unit of the server device 100, and includes a CPU (Central Processing Unit) 151, a ROM (Read Only Memory) 152, a RAM (Random Access Memory) 153, and an EEPROM (Electrically Erasable Programmable ROM). 154 is a microcomputer formed by being connected through the CPU bus 155.

  Here, the ROM 152 stores programs executed by the CPU 151, data necessary for processing, and the like, and the RAM 153 is mainly used as a work area in various processing. The EEPROM 154 is a so-called nonvolatile memory in which various parameters are stored.

  The format conversion unit 161 converts the format of digital content received through the connection end 101 and the communication unit 102 and the digital content received through the external device connection end 165 and the external I / F 164, and records the content on the content storage hard disk 103. For example, the format conversion of the content data is performed.

  Therefore, the format of the digital content supplied to the server device 100 is converted and recorded on the content storage hard disk 103, or the format of the digital content read from the content storage hard disk is converted and output from the server device 100. I can do it. The format conversion unit 161 can be formed as hardware, or can be realized by software executed in the control unit 150.

  The key operation unit 163 receives an operation input from the user, and is provided with an arrow key for moving the cursor, various function keys, and the like. An electrical signal corresponding to the operation input received through the key operation unit 163 is supplied to the control unit 150 through the key I / F 162. Thereby, the server apparatus 100 can perform an operation according to an operation input from the user.

  The external device connection end 165 and the external I / F 164 form a digital interface, accepts a digital signal supplied from a digital electronic device connected to the external device connection end, and can be processed by the server apparatus 100 Can be supplied to the control unit 150.

  Then, the control unit 150 records the digital data from the external I / F 162 on the content storage disk 103, sends it to the network through the communication unit 102, or converts the format through the format conversion unit 161 and then the content storage hard disk Or the digital content after conversion can be output to a network through the communication unit 102.

  FIG. 4 is a diagram for explaining the format conversion function of server apparatus 100 shown in FIG. For example, when a digital content of format A is received from a device that uses the CD 301, MD 302, and semiconductor memory 303 as a recording medium through the network connection terminal 101 or the external device connection terminal 165, the content is stored in the format A as it is for content storage. The data can be recorded on the hard disk 103, or can be converted into the format B by the function of the format conversion unit 161 and recorded on the content storage hard disk 103. Of course, the digital content of format A can be recorded in both format A and format B.

  Further, the server device 100 according to this embodiment outputs the digital content stored in the content storage hard disk 103 as it is, or uses the format conversion unit 161 to perform the format A or format B. It can also be converted into a format C different from that of the output.

  Note that the format conversion at the time of input of digital content to the server apparatus 100 and the format conversion at the time of output of digital content from the server apparatus 100 are performed in the format conversion unit 161 of the server apparatus 100 shown in FIG. Become. Therefore, in FIG. 4, as the function of the format conversion unit 161, the input (in) and the output (out) are described separately as format conversion 161 (in) and 161 (out).

  Then, as described above, the server apparatus 100 receives a request for providing a content list (content list list) from the client apparatus 200 via the connection end 101 and the communication unit 102 and notifies the control unit 150 of the request. In response to a request from the client device 200, the control unit 150 forms a list of digital contents (content list) stored in the content storage hard disk 103, and transmits the list through the communication unit 102 and the connection terminal 101. The packet is sent to the LAN as a packet and can be provided to the client device 200.

  In addition, the control unit 150 receives a digital content provision request transmitted from the client device 200 through the connection terminal 101 and the communication unit 102, and reads the digital content corresponding to the received provision request from the content storage hard disk 103. The read digital content can be used as it is or after the format of the read digital content is converted and sent to the LAN as an IP packet through the communication unit 102 and the connection terminal 101 to be provided to the requesting client apparatus 200. I have to.

  Note that the program executed by the CPU 151 of the control unit 150 is stored not only in the ROM 152 but also in the work hard disk 104, for example, and the CPU 151 of the control unit 150 reads the program stored in the hard disk 104. It can also be executed.

  Furthermore, the server device 100 of this embodiment includes an audio signal processing unit and an audio output terminal, a video signal processing unit and a video output terminal, and plays back and outputs digital content stored in the content storage hard disk 103. Or streaming playback based on digital content received through the communication unit 102 or the like. That is, the server device 100 also has a function as the client device 200 described in detail below.

  Next, the client device 200 will be described. FIG. 5 is a block diagram for explaining the client device 200, and shows a basic configuration of the PDA 5 or the like that functions as the client device 200, for example.

  As illustrated in FIG. 5, the client device 200 includes a connection end 201 for connecting to a LAN, a communication unit 202, a video signal processing unit 203, a display unit 204, an audio signal processing unit 205, a speaker 206, and the like. , A control unit 250, a key interface (hereinafter abbreviated as key I / F) 261, a key operation unit 262, and a remote control signal light receiving unit 263.

  The control unit 250 controls each unit of the client device 200, and is a microcomputer formed by connecting a CPU 251, a ROM 252, a RAM 253, and an EEPROM 254 through a CPU bus 255.

  Here, the ROM 252 stores programs executed by the CPU 251, data necessary for processing, and the like, and the RAM 253 is mainly used as a work area in various processes. The EEPROM 253 is a so-called non-volatile memory in which various data that should be retained even when the client apparatus 200 is powered off are recorded.

  The EEPROM 253 stores, for example, various parameters and the like. As will be described in detail later, the format of the format for specifying the format of the digital content when the server device 100 is requested to provide the digital content. A priority table holding information indicating the priority is recorded.

  The video signal processing unit 203 receives supply of digital still image data and digital moving image data in a predetermined format, decodes the data, forms an analog video signal to be supplied to the display unit 204, and outputs the analog video signal to the display unit 204. To supply. The display unit 204 is, for example, an LCD, a CRT (Cathode-Ray Tube), an organic EL (Electronic Luminescence), a plasma display, or the like. The display unit 204 receives a video signal from the video signal processing unit 203 and displays an image corresponding thereto. Display on your display screen.

  The audio signal processing unit 205 receives a digital audio signal in a predetermined format, decodes it, forms an analog audio signal to be supplied to the speaker 206, and supplies this to the speaker 206. The speaker 206 emits a sound corresponding to the sound signal from the sound signal processing unit.

  As described above, the client device 200 includes an image reproduction system including the video signal processing unit 203 and the display unit 204, and an audio reproduction system including the audio signal processing unit 205 and the speaker 206.

  As shown in FIG. 5, a key operation unit 262 is connected to the control unit 250 through the key I / F 261. The key operation unit 262 includes various operation keys. The key operation unit 262 receives an operation input from the user, forms an electric signal corresponding to the operation input, and supplies the electric signal to the control unit 250 through the key I / F 261. It is something that can be done.

  The remote control signal light receiving unit 263 can receive, for example, an infrared remote control signal from a remote commander (hereinafter referred to as a remote control) 270, convert it into an electrical signal, and supply it to the control unit 250. is there. The remote controller 270 includes various operation keys, receives an operation input from the user, and forms and sends a remote control signal according to the input.

  The key operation unit 262 and the remote control 270 are each provided with an arrow key, a determination key, and other operation keys for moving the cursor, and request a content list or select a desired digital content from the content list. Thus, various operations such as requesting the desired content can be accepted.

  Then, the control unit 250 of the client device 200 forms a content list provision request in response to a content list display instruction received from the user via the key operation unit 262 or the remote controller 270, and transmits the content list provision request to the communication unit 202, The IP packet is transmitted to the LAN through the connection end 201 and transmitted to the server apparatus 100.

  In response to this, the content list transmitted from the server device 100 is received through the connection end 201 and the communication unit 202, supplied to the control unit 250, and temporarily stored in the RAM 253. The content list stored in the RAM 253 is supplied to the display unit 204 through the video signal processing unit 203, and the content list is displayed on the display screen of the display unit 204. The user can select the desired digital content. To be done.

  When the target digital content is found on the content list, as described above, the cursor is moved to the display column for information on the target digital content (for example, the display column for the title or artist name of the digital content). By operating the positioning and determination keys, a provision request including the identification ID of the digital content is formed in the control unit 250, sent to the LAN as an IP packet through the communication unit 202 and the connection end 201, and sent to the server device 100. The

  Accordingly, since the target digital content is transmitted as an IP packet from the server apparatus 100, it is received through the connection end 201 and the communication unit 202. In this example, the image packet is transmitted through the control unit 250. The audio packet is supplied to the audio signal processing unit 205 to the video signal processing unit 203.

  As described above, in the video signal processing unit 203, an analog video signal is formed from the image data supplied to the video signal processing unit 203, and this is supplied to the display unit 204. Displayed on the display screen. Further, in the audio signal processing unit 205, an analog audio signal is formed from the audio data supplied thereto, and this is supplied to the speaker, whereby the audio of the digital content is emitted from the speaker. In this way, streaming reproduction of digital content from the server apparatus 100 in the client apparatus 200 is performed.

  In addition, the video signal processing unit 203 and the audio signal processing unit 205 of the client device 200 according to this embodiment can support a plurality of different formats. For example, an audio signal can correspond to LPCM, ATRAC, MP3, and the like, and a video signal can correspond to MPEG1, MPEG2, and the like.

  Which format is to be used is instructed by the priority order of the format used in the above-described priority order table formed in the EEPROM 254, and the digital data is provided from the server apparatus 100 in a format with a high priority order. So that it can be used.

  If there is no digital content in the target format, it is requested to provide digital content in a format with a low priority, or if there is little free bandwidth available on the network, a narrow-band format To be able to receive digital content.

  Note that, as described above, the client device 200 illustrated in FIG. 5 includes an image processing system including the video signal processing unit 203 and the display unit 204, and an audio processing system including the audio signal processing unit 205 and the speaker 206. Is provided. However, in the case of the stereo system 4 illustrated in FIG. 1, the basic configuration is a configuration that does not include the image processing system of the client device 200 illustrated in FIG. 5. In this case, when the stereo system 4 includes an LCD or the like and can display a content list or the like, the configuration is the same as that shown in FIG.

  Further, the basic configuration of the set top box 3 shown in FIG. 1 is such that the functions of the display unit 204 and the speaker 205 of the client device 200 shown in FIG.

  Further, the video signal processing unit 203 and the audio signal processing unit 205 of the client device 200 described above can be realized by software executed in the control unit 250, for example.

  As described above, the client device 100 according to this embodiment can support a plurality of formats, and which format is used, that is, the digital content requested to the server device 100. The format is determined in advance and is registered in the EEPROM 254 as a priority table.

FIG. 6 is a diagram for explaining an example of the priority order table. Here, a case where the digital content to be processed is audio data will be described as an example. Here, “sound quality priority” and “band priority” are provided as priority types. "Sound quality priority" means that priority is given to the sound quality during playback, and "Bandwidth priority" gives priority to the transmission of audio data properly without interruption, taking into consideration the available network bandwidth. Therefore, in the case of “sound quality priority”, the LPCM method which is an uncompressed format and can faithfully reproduce the original sound is set as the format with the highest priority, and thereafter, in the order of high reversibility, The formats usable in the client device 200 are ranked. In the case of “bandwidth priority”, the formats usable in the client apparatus 200 are ranked in descending order of the compression rate.

  In the case of the example shown in FIG. 6, in the case of “sound quality priority”, the priority order 1 is set to format A, the priority order 2 is set to format B,... In the case of “bandwidth priority”, the priority order 1 is set to format B, the second priority order is set to format A,... Also, as shown in FIG. 6, the priority order table is provided with a selection flag so that it is possible to select between “sound quality priority” and “band priority”. . In the case of the example shown in FIG. 6, “sound quality priority” is selected.

  FIG. 7 and FIG. 8 are diagrams for explaining processing when requesting provision of digital content in consideration of registration information in the priority table. For example, as shown in FIG. 6, it is assumed that “sound quality priority” is selected in the registered priority order table. In this case, when the user of the client device 200 selects and confirms the digital content requested to be provided to the server device 100, the control unit 250 of the client device 200 displays the priority shown in FIG. 6 formed in the EEPROM 254. With reference to the table, as shown in FIG. 7A, the server apparatus 100 is confirmed whether or not digital content can be provided by the format A with the highest priority when the priority type is “sound quality priority”.

  In this example, the content storage hard disk 103 of the server device 100 holds data formatted in the format A and the format B as shown in FIG. 7A for the same digital content. And In this case, the server apparatus 100 returns a response indicating that digital content in the requested format A can be provided.

  Upon receiving the response that the digital content can be provided in the format A, the client device 200 forms a provision request for providing the target digital content in the format A, and transmits this to the server device. In response to the provision request, the server device 100 reads out the digital content of the target format A from the content storage hard disk 103 and provides it to the requesting client device 200 so that the digital content can be reproduced with high quality. I have to.

  If the requested format A digital content is not stored in the server apparatus 100 and cannot be provided, a response indicating that the requested format A cannot be provided is returned. Reference numeral 200 refers to the priority table, confirms whether or not digital content can be provided in the format B of which the priority is second when the priority classification is “sound quality priority”. When the provision of the desired digital content in the format B is requested and the provision is impossible, it is confirmed whether or not the provision can be made in a format with a lower order.

  Further, as shown in FIG. 6, when “bandwidth priority” in the registered priority table is selected, the user of the client device 200 selects the digital content requested to be provided to the server device 100, Upon confirmation, the control unit 250 of the client device 200 refers to the priority order table shown in FIG. 6 formed in the EEPROM 254, and as shown in FIG. 7B, priority when the priority type is “bandwidth priority”. It is confirmed with the server apparatus 100 whether or not digital content can be provided in the format B of the first rank.

  In this example, the content storage hard disk 103 of the server apparatus 100 holds data formatted in each of format A and format B as shown in FIG. 7B for the same digital content. And In this case, the server apparatus 100 returns a response indicating that digital content can be provided in the requested format B.

  The client device 200 that has received the response that the digital content can be provided in the format B forms a provision request for providing the intended digital content in the format B, and transmits this to the server device. In response to this provision request, the server device 100 reads out the digital content of the target format B from the content storage hard disk 103 and provides it to the requesting client device 200 so that the digital content can be reproduced with high quality. I have to.

  If the requested format B digital content is not stored in the server apparatus 100 and cannot be provided, a response indicating that the requested format B cannot be provided is returned. 200 refers to the priority table, confirms whether or not digital content can be provided in the format A with the second highest priority when the priority classification is “bandwidth priority”. When the provision of the desired digital content is requested in the format A and the provision is impossible, it is confirmed whether or not the provision can be made in a format with a lower order.

  FIG. 8 is a diagram for explaining a digital content providing process involving digital content format conversion in the server apparatus 100. For example, as in the case described with reference to FIG. 7A, “sound quality priority” is selected in the priority order table of the EEPROM 254, and the user of the client device 200 requests the server device 100 to provide the digital content. When the content is selected and confirmed, the control unit 250 of the client apparatus 200 refers to the priority order table shown in FIG. 6 formed in the EEPROM 254, and as shown in FIG. In the case of “sound quality priority”, the server apparatus 100 is checked to see if digital content can be provided in the format A having the highest priority.

  In this example, it is assumed that the content storage hard disk 103 of the server apparatus 100 holds only data formatted in the format B, as shown in FIG. In this case, the server apparatus 100 converts the digital content in the format B into the format A and returns a response indicating that the digital content in the requested format A can be provided if it can be provided.

  Upon receiving the response that the digital content can be provided in the format A, the client device 200 forms a provision request for providing the intended digital content in the format A, and transmits this request to the server device 100. . In response to this provision request, the server device 100 reads out the digital content of the target format B from the content storage hard disk 103, converts it into the format A, and then provides it to the client device 200 of the request source. It enables high-quality playback of digital content.

  Similarly to the case described with reference to FIG. 7B, “bandwidth priority” is selected in the priority order table of the EEPROM 254, and the user of the client apparatus 200 requests the server apparatus 100 to provide the digital. When the content is selected and confirmed, the control unit 250 of the client device 200 refers to the priority order table shown in FIG. 6 formed in the EEPROM 254, and as shown in FIG. In the case of “bandwidth priority”, the server apparatus 100 is checked whether digital content can be provided by the format B having the highest priority.

  In this example, it is assumed that the content storage hard disk 103 of the server apparatus 100 holds only data formatted in the format A as shown in FIG. In this case, the server apparatus 100 converts the digital content in the format A into the format B and returns a response indicating that the digital content in the requested format B can be provided if it can be provided.

  The client device 200 that has received the response that the digital content can be provided in the format B forms a provision request for providing the intended digital content in the format B, and transmits this request to the server device 100. . In response to this provision request, the server device 100 reads the target format A digital content from the content storage hard disk 103, converts it into the format B, and provides it to the requesting client device 200, thereby providing It enables high-quality playback of digital content.

  In this way, the server apparatus 100 converts the requested format digital content into the requested format by the function of its own format conversion unit 261 even when the digital content in the requested format does not exist in its own content storage hard disk 103. In response to a provision request from the client device 200, the requested digital content is sent back in response to the provision request from the client device 200. It can also be converted into the required format and output.

  Next, processing performed when the client device 200 requests the server device 100 to provide digital content and requests the provision of the desired digital content will be described as processing performed by the user, the client device 200, and the server device 100, respectively. To do. FIG. 9 is a diagram for explaining an example of using digital content as “sound quality priority”.

  Before the user of the client apparatus 200 requests the server apparatus 100 to provide the desired digital content, the user apparatus 200 creates the priority order table and selects the priority classification for the client apparatus 200 (step S1). ). As a result, a priority table in which the priority classification is “sound quality priority”, the first priority is format A, and the second priority is format B is formed in the EEPROM 254 of the client apparatus 200 as shown in FIG. Is done.

  Then, the user of the client device 200 instructs the client device 200 to display the content list by operating the key operation unit 262 or the remote controller 270 of the client device 200, and through the displayed content list, The selection of the target digital content and the reproduction of the selected digital content are instructed (step S2).

  Upon receiving this playback instruction, the client device 200 refers to the priority order table, and confirms whether digital content can be provided in that format in order from the format with the highest priority in the priority classification “sound quality priority”. In response to this, the server apparatus 100 determines whether or not it is possible to provide the digital content in the format instructed for confirmation based on the format of the digital content held by itself and the format conversion function of itself. A response is returned (step S3).

  Then, the client device 200 forms a provision request for requesting digital content to be provided in a format that has been confirmed to be initially available, and transmits this request to the server device 200 (step S4). When the server device 100 receives the provision request from the client device 200, the server device 100 reads out or reads out the digital content of a predetermined format requested for provision from the content storage hard disk 103 based on information included in the provision request. The converted digital content is converted into the instructed format and transmitted to the client device 200 (step S5).

  The client device 200 sequentially receives the IP packets of the intended digital content in the format instructed from the server device 100 and reproduces them (step S6). As a result, the client apparatus 200 receives the digital content intended by the user from the server apparatus 100 and can use it.

  Note that the priority order table formed in step S1 is stored and held in the EEPROM 254 of the client device 200, and therefore need not be changed unless the usage mode of the client device 200 is changed. Therefore, once the priority table is formed, the processing from step S2 is repeated thereafter, so that the intended digital content can be provided and reproduced in format A. .

  FIG. 10 is a diagram for explaining an example of using digital content as “bandwidth priority”. As in the case of sound quality priority shown in FIG. 9, the user of the client device 200 creates a priority table and selects a priority category before requesting the server device 100 to provide the desired digital content. 200 is performed (step S11). As a result, a priority table in which the priority classification is “bandwidth priority”, the first priority is format B, and the second is format A is formed in the EEPROM 254 of the client device 200 as shown in FIG. Is done.

  Then, the user of the client device 200 instructs the client device 200 to display the content list by operating the key operation unit 262 or the remote controller 270 of the client device 200, and through the displayed content list, The selection of the target digital content and the reproduction of the selected digital content are instructed (step S12).

  Upon receiving this playback instruction, the client device 200 refers to the priority order table and confirms whether digital content can be provided in that format in order from the format with the highest priority when the priority classification is “bandwidth priority”. In response to this, the server apparatus 100 determines whether or not it is possible to provide the digital content in the format instructed for confirmation based on the format of the digital content held by itself and the format conversion function of itself. A response is returned (step S13).

  Then, the client apparatus 200 forms a provision request for requesting provision of digital content in a format that has been confirmed to be initially available, and transmits this request to the server apparatus 200 (step S14). When the server device 100 receives the provision request from the client device 200, the server device 100 reads out or reads out the digital content of a predetermined format requested for provision from the content storage hard disk 103 based on information included in the provision request. The converted digital content is converted into the instructed format and transmitted to the client device 200 (step S15).

  The client device 200 sequentially receives the IP packets of the intended digital contents in the format instructed from the server device 100 and reproduces them (step S16). As a result, the client apparatus 200 receives the digital content intended by the user from the server apparatus 100 and can use it.

  In this case as well, as in the case of sound quality priority shown in FIG. 9, the priority order table formed in step S11 is stored and held in the EEPROM 254 of the client apparatus 200. It is not necessary to change unless the aspect changes. Therefore, once the priority order table is formed, the processing from step S12 is repeated thereafter, so that the intended digital content can be provided and reproduced in format A. .

  Next, details of processing performed by each of the client device 200 and the server device 100 illustrated in FIGS. 9 and 10 will be described with reference to the flowcharts of FIGS. 11, 12, and 13.

  First, as described in step S1 of FIG. 9 and step S11 of FIG. 10, the priority table setting process performed in the client apparatus 200 will be described with reference to the flowchart of FIG. When the item “set priority table” is selected from the list of executable processes (menu list) by operating the key operation unit 263 or the remote controller 270 of the client device 200, the control unit 250 The priority table setting process shown in FIG.

  First, as shown in FIG. 6, the control unit 250 displays a priority order setting screen in which a selection flag, a priority classification, and a priority order can be input (step S <b> 101), and the corresponding part of the priority order setting screen. Then, a selection flag, a priority classification, and a format instruction for each priority order input via the key operation unit 263 and the remote controller 270 are received (step S102). Then, it is determined whether the input has been completed and a confirmation input has been accepted (step S103).

  If it is determined in step S103 that no confirmation input has been received, it is determined whether an end instruction has been received (step S104). If it is determined in step S104 that an end instruction has not been received, the process from step S102 is repeated so that information about the priority table can be input, and an end instruction has been received. If it is determined, the priority table is not formed, and the process shown in FIG. 11 is terminated.

  If it is determined in step S103 that a confirmation input has been received, a priority table as shown in FIG. 6 is formed based on the received information and recorded in the EEPROM 254 (step S105). The process shown in FIG.

  In this way, the user can form a priority table and register it in the EEPROM 254 of the client device 200 at an appropriate time. Although FIG. 6 shows the cases of “sound quality priority” and “band priority”, it is of course possible to register only one of them.

  Next, the digital to be performed in the client device 200 through step S2, step S3, step S4, and step S6 in FIG. 9 or through step S12, step S13, step S14, and step S16 shown in FIG. The content streaming playback process will be described with reference to the flowchart of FIG.

  For example, a content list to be provided from the server device 100 is displayed on the display unit 204 of the client device 200, and a selection input of digital content to be reproduced is received (step S201). In the process of step S201, a page break of the content list and a cursor movement are performed in accordance with an operation input from the user received through the key operation unit 263 and the remote controller 270, and a reproduction instruction input and an end instruction input are received. To be.

  Then, the control unit 250 determines whether or not a reproduction instruction input has been accepted (step S202). If it is determined that the reproduction instruction input has not been accepted, the control unit 250 determines whether or not an end instruction input has been accepted (step S203). If it is determined in step S203 that an end instruction input has not been received, the process from step S201 is repeated to accept a digital content selection input. If it is determined in the determination process in step S203 that an end instruction input has been received, the process shown in FIG. 12 ends.

  In the determination process of step S202, when it is determined that the reproduction instruction input, that is, the selection confirmation input of the digital content to be used for reproduction is received, the control unit 250 refers to the priority order table stored in the EEPROM 254, and formats Is initialized (step S204). The process of step S204 is a process of setting to use a format corresponding to the priority order table (format of the first priority order of the selected priority classification).

  Then, a request for inquiring whether or not digital content can be provided in the format set in step S204 is formed and transmitted (step S205), and a response from the server apparatus 100 corresponding to the request is received and the target is received. It is determined whether digital content can be provided in a format (step S206).

  When it is determined in step S206 that the digital content in the target format can be provided, the control unit 250 requests to provide the digital content selected by the user in the target format. A request is generated, and the request is transmitted to the network through the communication unit 202 and the connection end 201 and transmitted to the server apparatus 100 (step S207).

  Then, the digital content transmitted from the server apparatus 100 through the network in the form of an IP packet is received through the connection end 201 and the communication unit 202, and the audio data is supplied to the audio signal processing unit 205 through the control unit 205. Also, the video data is supplied to the video signal processing unit 203 and sequentially played to perform streaming playback (step S208), and the processing shown in FIG.

  If it is determined in step S206 that it is impossible to provide digital content in the target format, the control unit 250 refers to the priority order table stored in the EEPROM 254, and the priority order is one order lower. The format setting is changed to use the format (step S209), and the processing from step S205 is repeated.

  Prior to the format change process in step S209, it is checked whether or not a lower format than the currently set format exists in the priority table. If not, the lower format is set. It is also possible to notify that it is not possible to receive the provision of digital content from the server device 100 by displaying a message notifying that there is no content.

  As described above, the client device 200 provides the target digital content in the format in which the priority order is determined without making the user particularly aware of the format of the digital content by using the preset priority order table. Can be requested and played back. In this case, since the client apparatus 200 knows in which format the provision of digital content is requested, there is no possibility that playback cannot be performed.

  Next, as described in step S4 in FIG. 9 and step S14 in FIG. 10, the digital content providing process performed in the server apparatus 100 will be described with reference to the flowchart in FIG.

  The server device 100 monitors whether or not a request addressed to itself has been received (step S301). When it is determined that a request addressed to itself has been received, it determines whether or not it is a content provision request. (Step S302). When determining in step S302 that the content is a provision request, the control unit 150 determines the requested digital content and its format based on the information included in the received provision request (step S302). S303).

  Then, the control unit 150 reads out the digital content in the format determined in step S303 from the content storage hard disk 103, transmits it to the requesting client device (step S304), and ends the processing in FIG.

  If it is determined in step S302 that the received request is not a content provision request, it is determined whether or not the received request is a format confirmation request (step S305).

  If it is determined in the determination processing in step S305 that the request is a format confirmation request, the digital content format stored in the content storage hard disk 103 and the digital format in the requested format based on its own format conversion function are used. It is confirmed whether or not content can be provided (step S306).

  Then, as a result of the confirmation in step S306, it is determined whether digital content can be provided in the format requested for confirmation (step S307). If it is determined in step S307 that the digital content can be provided in the format requested for confirmation, a response is formed and transmitted to the requesting client device (step S308). The process of FIG. 13 is terminated.

  If it is determined in step S307 that digital content cannot be provided in the format requested for confirmation, an impossible response is formed and transmitted to the requesting client device (step S309). Then, the process shown in FIG.

  If it is determined in step S305 that the request is not a format confirmation request, the server apparatus 100 performs other processing according to the received request, for example, a content list (a list of digital contents that can be provided), or the like. Is performed (step S310).

  As described above, the server apparatus 100 can respond to the format confirmation request from the client apparatus 200 and can provide the requested digital content in the requested format in response to the digital content provision request. It can be done.

[Second Embodiment]
In the first embodiment described above, by using the priority order table formed in the EEPROM 254, the digital content can be provided without making the user aware of the format of the digital content. However, depending on the communication situation of the network to which the server apparatus 100 and the client apparatus 200 are connected, it may be difficult to provide digital content in a format with high priority.

  For example, in the network, when other network devices are communicating, the usable bandwidth of the network is narrowed. In this case, a wide transmission band is required. However, if digital content in the LPCM format with the best sound quality is requested and streaming playback is performed, the network usage band is insufficient, so the so-called sound skipping is performed. It can be a cause.

  Therefore, in the second embodiment described below, the client apparatus 200 cannot confirm a network communication status (usage status) and cannot secure a sufficient band for transmitting digital content in a planned format. When it is determined, the provision of digital content is requested in a format with a low priority (in this case, a format that requires a narrow bandwidth).

  Also in the second embodiment, the configurations and functions of the LAN system, the server device 100, and the client device 200 are the same as those in the first embodiment described with reference to FIGS. . In the case of the second embodiment, the digital content reproduction processing in the client device 200 is different from that in the first embodiment described above.

  FIG. 14 is a diagram for explaining processing performed in each of the user, the client device 200, and the server device 100 in the second embodiment. The example of FIG. 14 is an example in the case of using digital content as “sound quality priority”.

  Before the user of the client apparatus 200 requests the server apparatus 100 to provide the desired digital content, the user apparatus 200 creates the priority order table and selects the priority classification for the client apparatus 200 (step S21). ). As a result, as shown in FIG. 14, a priority table in which the priority classification is “sound quality priority”, the first priority is format A, and the second priority is format B is formed in the EEPROM 254 of the client device 200. Is done.

  Then, the user of the client device 200 instructs the client device 200 to display the content list by operating the key operation unit 262 or the remote controller 270 of the client device 200, and through the displayed content list, The user is instructed to select the desired digital content and to reproduce the selected digital content (step S22).

  Upon receiving this playback instruction, the control unit 250 of the client device 200 refers to the priority order table formed in the EEPROM 254, and in order from the format with the highest priority in the priority classification “sound quality priority”, A process for confirming the communication status of the transmission path (network) for confirming whether or not a sufficient bandwidth for transmission can be ensured is performed (step S23). The server 100 is inquired as to whether or not the digital content can be provided, and a confirmation process for providing is performed (step S24).

  That is, in the confirmation processing in step S23 and step S24, when it is confirmed that the available bandwidth of the network is insufficient or the server apparatus 100 cannot provide digital content in the target format. Based on the information in the priority table, the format is changed to a format having a low priority, and a network bandwidth required for transmission can be sufficiently secured and the server device 100 can select a compatible format.

  The communication status confirmation process performed in step S23 is performed by probing a small number of measurement packets from the client device 200 at a constant speed, and obtaining an available bandwidth from the measurement result of the RTT (Round Trip Time), Echo packet such as ping using ICMP (Internet Control Message Protocol) echo packet is reciprocated between devices (in this example, between client device 200 and server device 100) for transmitting and receiving data, and the time required for it Various methods such as checking the communication status of the network can be used.

  Then, the client apparatus 200 generates a provision request for requesting to provide a target digital content in a format that can sufficiently secure a network bandwidth required for transmission and that the server apparatus 100 can also handle. 100 (step S25).

  When the server device 100 receives the provision request from the client device 200, the server device 100 reads out the intended digital content of the predetermined format requested for provision from the content storage hard disk 103 based on the information included in the provision request, Alternatively, the read digital content is converted into an instructed format and transmitted to the client device 200 (step S26).

  The client device 200 sequentially receives and reproduces the IP packets of the intended digital content in the format instructed from the server device 100 (step S27). As a result, the client apparatus 200 receives the digital content intended by the user from the server apparatus 100 and can use it.

  Next, digital content streaming playback processing performed in the client device 200 through steps S22, S23, S24, S25, and S26 of FIG. 14 will be described with reference to the flowchart of FIG. .

  For example, a content list to be provided from the server device 100 is displayed on the display unit 204 of the client device 200, and a selection input of digital content to be reproduced is received (step S401). In the process of step S401, in response to an operation input from the user received through the key operation unit 263 and the remote controller 270, a page break of the content list and a cursor movement are performed, and a reproduction instruction input and an end instruction input are received. To be.

  Then, the control unit 250 determines whether or not a reproduction instruction input has been accepted (step S402). If it is determined that the reproduction instruction input has not been accepted, the control unit 250 determines whether or not an end instruction input has been accepted (step S403). If it is determined in step S403 that the end instruction input has not been received, the process from step S401 is repeated, and the digital content selection input is received. If it is determined in step S403 that the end instruction input has been received, the process shown in FIG. 15 is ended.

  When it is determined in step S402 that the reproduction instruction input, that is, the selection confirmation input of the digital content to be reproduced has been received, the control unit 250 checks the available bandwidth by checking the communication status of the network. (Step S404). Then, it is determined whether or not a minimum bandwidth is available for transmitting the digital content (step S405). When it is determined that the bandwidth is insufficient, the user is notified of the insufficient bandwidth (step S406). The process shown in FIG. 15 is terminated without transmitting the provision request.

  Note that, in the determination process in step S405, as described above, it is confirmed whether or not a minimum free bandwidth exists. Here, the lowest available bandwidth is a bandwidth used in a format that uses the least bandwidth among the formats registered in the priority table.

  If it is determined in step S405 that the bandwidth is insufficient (a minimum bandwidth cannot be secured), the control unit 250 refers to the priority table stored in the EEPROM 254 and initializes the format format. Is performed (step S407). The process of step S407 is a process of setting to use a format corresponding to the priority order table (the first priority order format of the selected priority classification).

  Then, it is determined whether or not a sufficient band is available when digital content is transmitted in the format set in step S407 (step S408). Here, the sufficient bandwidth is the used bandwidth of the format that tries to make the most bandwidth among the formats registered in the priority table.

  If it is determined in step S408 that a sufficient bandwidth is available, a request for inquiring whether digital content can be provided in the format set in step S407 is formed and transmitted (step S409). In response to the response, the server apparatus 100 receives a response from the server apparatus 100, and determines whether or not digital content can be provided in the target format (step S410).

  When it is determined in step S410 that the digital content in the target format can be provided, the control unit 250 provides the digital content selected by the user to be provided in the target format. A request is generated, sent to the network through the communication unit 202 and the connection end 201, and transmitted to the server device 100 (step S411).

  Then, the digital content transmitted from the server apparatus 100 through the network in the form of an IP packet is received through the connection end 201 and the communication unit 202, and the audio data is supplied to the audio signal processing unit 205 through the control unit 205. Further, the video data is supplied to the video signal processing unit 203 and sequentially played back so that streaming playback is performed (step S412), and the processing shown in FIG.

  If it is determined in step S408 that sufficient bandwidth is not available, or if it is determined in step S410 that it is impossible to provide digital content in the target format, the control unit Reference numeral 250 refers to the priority order table stored in the EEPROM 254, changes the setting of the format so that the format with the next lower priority is used (step S413), and repeats the processing from step S408. .

  Prior to the format change process in step S209, it is checked whether or not a lower format than the currently set format exists in the priority table. If not, the lower format is set. It is also possible to notify that it is not possible to receive the provision of digital content from the server device 100 by displaying a message notifying that there is no content.

  As described above, also in the case of the second embodiment, the client apparatus 200 uses the priority order table set in advance, so that the priority order can be set without making the user particularly aware of the format of the digital content. It is possible to request provision of desired digital content in a predetermined format and to reproduce it. In this case, since the client apparatus 200 knows in which format the provision of digital content is requested, there is no possibility that playback cannot be performed.

  In addition, in the case of the second embodiment, since the available bandwidth of the network is also checked, it is possible to avoid receiving provision of digital contents when the transmission bandwidth of the network is insufficient. Can do. Therefore, it is possible to prevent streaming reproduction that may cause so-called sound skipping, and to establish a highly reliable network usage environment.

  That is, in the case of the client device 200 according to the second embodiment, the device has a plurality of tables in which the priorities of the respective formats are described, and the user can select a favorite table to be effective. The client device displays the digital content information, and does not display the digital content format information unless specifically instructed by the user.

Immediately after the user instructs the reproduction of the digital content, the client device 200
(1) Investigate available network bandwidth.

(2) If it is confirmed that the minimum bandwidth does not exist, the user is notified and the transmission apparatus is not requested to transmit. As described above, the minimum bandwidth is a bandwidth used in a format that uses the least bandwidth among the formats described in the table.

(3) If it is confirmed that there is a minimum bandwidth, the server apparatus is inquired whether transmission is possible based on the order of priority in the table. In this case, it is also confirmed that a predetermined bandwidth is available on the network.

(4) Request transmission of digital contents in a format having the highest priority among the transmittable formats.

  By doing so, the format is determined in consideration of the bandwidth that can be actually used in the network under the restriction of the priority of the format desired by the user of the client device, and the digital content is provided to the server device. Since the request is made, it is possible to stream and play the digital content with the quality desired by the user without causing sound interruption.

  The operation of the server device 100 in the second embodiment is the same as the operation of the server device 100 of the first embodiment described with reference to FIG.

  In the case of the second embodiment, the network communication status is checked immediately before requesting the provision of digital content, and whether or not the free bandwidth is sufficient is confirmed. Even after starting from the apparatus 100, for example, the communication status of the network is confirmed at a predetermined timing, and when the available bandwidth becomes insufficient, the format of the digital content being provided may be changed. Good. In this case, confirmation of the network communication status may be executed by the client apparatus 200 and notified to the server apparatus 100, or may be executed by the server apparatus 100 and notified to the client apparatus.

  In the first and second embodiments, as can be seen from the above description, the priority storage means is realized by the EEPROM 254, the forming means is realized by the control unit 250, and the transmission means and the reception means are The communication unit 202 is mainly realized. Inquiry means and bandwidth confirmation means are realized by the cooperation of the control unit 250 and the communication unit 202.

[Modification]
In the embodiment described above, the server apparatus 100 determines whether or not it is possible to automatically provide the digital content in the format to be used by automatically determining the format of the digital content requested to be provided based on the priority table. I contacted you. By doing so, it is possible to request provision of the desired digital content in a format that can be reliably handled by the server apparatus 100. However, it is not limited to this.

  For example, if a provision request for requesting provision of the desired digital content is formed in the order of the format with the highest priority, and this is transmitted and a response indicating that the provision is impossible is returned, the purpose is set in a format with a lower priority. It is also possible to repeat the formation and transmission of a provision request for requesting provision of digital content.

  In this case, in the process shown in FIG. 12, the process of step S205 may be omitted, and the processes of step S206 and step S209 may be performed after the process of step S207. In this case, the determination process in step S206 may be performed by confirming a response from the server apparatus 100 indicating whether or not the provision request from the client apparatus 200 can be handled.

  Similarly, in the case of the process shown in FIG. 15, the process of step S409 may be omitted, and the processes of step S410 and step S413 may be performed after the process of step S411. In this case, the determination process in step S410 may be performed by confirming a response from the server apparatus 100 indicating whether or not the provision request from the client apparatus 200 can be handled.

  In addition, as described above, each time the format to be used is changed based on the information in the priority table, the server device is inquired as to whether the format is compatible, or a provision request is formed for each format. However, the present invention is not limited to this.

  For example, all of the information registered in the priority table or all of the information on the selected priority category is transmitted to the server device 100, and the server device 100 can cope with it. Thus, it is also possible to select a format with as high a priority as possible and provide digital content in response to a request from the client device 200.

  That is, the client device 200 transmits, for example, the provision request for the identification ID of the digital content for which the provision is requested and the priority information in the priority table. Then, the server apparatus 100 selects a format with the highest possible priority among the formats that can be supported by the own apparatus based on the priority order information from the client apparatus 200 for the digital content requested to be provided. The digital content requested in (1) may be provided to the requesting client device 200.

  In this case, the client device 200 does not know in which format the digital content is provided. However, the client device 200 is notified of which format is used from the server device 100 or provided from the server device 100. It is possible to identify the format selected in the server apparatus 100 by analyzing the digital content, and to perform the decoding process without delay.

  In this case, if there is no digital content in a format with a high priority, the server device may convert the format to form digital content in a format with a high priority. If there is digital content in a lower format, it is possible to output it.

  In the above-described embodiment, the case where digital content streaming playback is performed has been described as an example. However, the present invention is not limited to this. That is, the present invention can also be used when digital content is downloaded to a client device. In this case, the free bandwidth of the network is taken into consideration, and the format of the digital content to be downloaded can be confirmed and determined between the client device and the server device as described above.

  Specifically, for example, when downloading music data (digital content) of 10 songs per hour, the free bandwidth of the network, the time limit of 1 hour, and the data amount of 10 music data are set. It is also possible to select an appropriate format in consideration.

  In the embodiment described above, the format has been described as MPEG, MPEG2, JPEG, etc. for LPCM, ATRAC, MP3, and video data content for audio data content, but is not limited thereto. It goes without saying that various formats are targeted.

  Further, for example, even LPCM and ATRAC have different bit rates. That is, the present invention is not intended only for formats with different names, and even if the basic principle is the same format, those with different bit rates can be treated as different formats.

  Further, the present invention can be applied to various network devices that can be connected to a network such as a LAN system, such as a PDA, a stereo system, a set top box, and a personal computer.

  In the above-described embodiment, the communication is performed using the IP packet. However, the present invention is not limited to this. For example, the present invention can be applied to an electronic device that is connected through an IEEE (Institute of Electrical and Electronics Engineers) 1394 digital interface and performs communication using packets defined by IEEE 1394. In IEEE 1394, each device registers a bandwidth to be used when using the network in a device uniquely determined on the network. In this case, information about the band may be acquired from the registration destination device uniquely determined as described above. In addition, the present invention can be applied not only to packet communication but also to various electronic devices that can be connected through a network.

  Needless to say, the transmission path (network) of digital content or the like may be either wireless or wired.

It is a figure for demonstrating the outline | summary of the LAN system of embodiment. It is a figure for demonstrating the streaming reproduction | regeneration of the music data which can be performed in the LAN system of embodiment. 2 is a block diagram for explaining a server device 100. FIG. 4 is a block diagram for explaining a format conversion function of the server apparatus 100. FIG. 4 is a block diagram for explaining a client device 200. FIG. It is a figure for demonstrating the priority order table of the utilization of a format. It is a figure for demonstrating the process in the case of request | requiring provision of the digital content which considered the registration information of the priority table. It is a figure for demonstrating the process in the case of request | requiring provision of the digital content which considered the registration information of the priority table. It is a figure for demonstrating the example of a process in the case of using a digital content as "sound quality priority." It is a figure for demonstrating the example of a process in the case of utilizing a digital content as "band priority." It is a flowchart for demonstrating the setting process of a priority table. 6 is a flowchart for explaining digital content streaming playback processing performed in the client device 200; 4 is a flowchart for explaining a digital content providing process performed by the server apparatus 100. It is a figure for linking and explaining processing performed by each of a user, a client device 200, and a server device 100 in other embodiments. It is a flowchart for demonstrating the streaming reproduction process of the digital content performed with the client apparatus 200 in other embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Server apparatus, 101 ... Connection end, 102 ... Communication part, 103 ... Content storage hard disk, 104 ... Work hard disk, 150 ... Control part, 151 ... CPU, 152 ... ROM, 153 ... RAM, 154 ... EEPROM, 155 ... CPU bus, 161 ... format conversion unit, 162 ... key interface (key I / F), 163 ... key operation unit, 164 ... external interface (external I / F), 165 ... external device connection end, 200 ... client device, 201 ... Connection end, 202 ... Communication unit, 203 ... Video signal processing unit, 204 ... Display unit, 205 ... Audio signal processing unit, 206 ... Speaker 206, 250 ... Control unit, 251 ... CPU, 252 ... ROM, 253 ... RAM 254 ... EEPROM, 255 ... CPU path, 261 ... key interface Scan (key I / F), 262 ... key operating unit, 263 ... remote control signal light-receiving section, 270 ... remote commander (remote control)

Claims (8)

A network device that receives distribution of provided information from a server device connected through a network,
Priority storage means for storing information indicating the priority order of the format specified for the provision information to be distributed from the server device;
Forming means for forming a provision request for provision information intended for formatting according to information indicating the priority order stored in the priority order storage means;
Transmitting means for transmitting the provision request formed by the forming means to the server device through the network;
A network device comprising: receiving means for receiving the provision information provided from the server device. The network device according to claim 1,
Inquiry means for making an inquiry as to whether or not the server device is a compatible format in order from the format with the highest priority stored in the priority order storage means,
The network device is characterized in that the forming means forms the provision request for the target provision information in the format in response to a response from the server device indicating that the format is compatible through the inquiry means. The network device according to claim 2, wherein
In order from the highest priority format stored in the priority storage means, the bandwidth confirmation means for confirming whether or not there is a sufficient bandwidth for transmitting provided information by the format,
The forming means is a format that has been confirmed by the bandwidth confirmation means to have a sufficient bandwidth and that it can be transmitted properly, and that is a format that can be supported through the inquiry means. A network device, characterized in that the request for providing the target provision information in a format in which a response is accepted is formed. The network device according to claim 1,
In order from the highest priority format stored in the priority storage means, the bandwidth confirmation means for confirming whether or not there is a sufficient bandwidth for transmitting provided information by the format,
The network apparatus according to claim 1, wherein the forming unit forms the provision request for the target provision information in a format in which it is confirmed that the band confirmation unit has a sufficient band and can be transmitted appropriately. An information request method in a network device that receives distribution of provided information from a server device connected through a network,
A priority order setting step for preliminarily storing information indicating the priority order of the format specified for the provision information to be received from the server device in a predetermined memory;
A selection input receiving step for receiving selection input of provision information intended to receive provision from the server device;
In the selection input receiving step, when the selection input of the provision information to be provided is accepted, the provision of the selected provision information in a format corresponding to the information indicating the priority stored in the memory A provision request formation step to form a request; and
An information requesting method comprising: a transmission step of transmitting the provision request formed in the provision request formation step to the server device through the network. The information request method according to claim 5,
An inquiry step for making an inquiry as to whether or not the server device is a compatible format in order from the format with the highest priority stored in the memory;
In the provision request forming step, in the inquiry step, a provision request for the selected provision information in the format that has received a response from the server device indicating that the format is compatible is formed. Request method. The information request method according to claim 6,
A bandwidth confirmation step for confirming whether or not there is a sufficient bandwidth for transmitting provided information in accordance with the format in order from the format with the highest priority stored in the memory,
In the provision request forming step, a server that indicates that there is a sufficient bandwidth in the bandwidth confirmation step and that it is confirmed that transmission can be performed properly, and that the format is compatible in the inquiry step. An information requesting method comprising: forming a request for providing the selected provision information in a format in response to a response from the apparatus. The information request method according to claim 5,
A bandwidth confirmation step for confirming whether or not there is a sufficient bandwidth for transmitting provided information in accordance with the format in order from the format with the highest priority stored in the memory,
The providing request forming step forms a request for providing the selected providing information in a format that has been confirmed that there is a sufficient band in the band checking step and that transmission can be properly performed. Request method.

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