JP2008118329A - Content-transmitting device and content-receiving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a content-transmitting device and a content-receiving device capable of holding the newest attribute information, even when an attribute information on a content changes, since recording of the content in recording is completed during reproducing via a network. <P>SOLUTION: The content transmitting device divides an AV content into a plurality of partial contents, appends a protocol header, including the attribute information on the AV content at the point of transmission to the partial content, and transmits the partial content. The content-receiving device receives the AV content in a state where it is divided into the plurality of partial contents, and acquires the attribute information on the AV content at the point of reception of the partial contents from the header that received. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a content transmitting apparatus and a content receiving apparatus for viewing AV content via a network.

  In recent years, content exchange via a network has been actively performed. If a home LAN is constructed, for example, AV content stored in a PC or HDD recorder can be streamed from a TV or DVD player in another room.

  The procedure for viewing content via the network is as follows. First, the client searches for a device connected to the network. When a device is found, a device to be connected as a server is selected from the found devices. Next, a content list information acquisition request is transmitted to the selected device, and attribute information about the content held by the server is acquired. The attribute information related to the content includes information such as the title name of the content, recording start time, recording end time, recording time, channel number, and recording mode. On the client side, the acquired content list information is displayed on the monitor screen, and the user selects the content he / she wants to see. The content reproduction request from the user is transmitted to the server as a content acquisition request from the client. The server that has received the content acquisition request transmits the content data to the client, and the client that has received the content decrypts the data, thereby allowing the client to view the content.

  In content playback via a network, special playback such as fast forward, rewind, and skip may be performed. Special playback can be realized by specifying the data range of the content to be acquired. For example, if content transmission is performed using HTTP (Hyper Text Transfer Protocol) over TCP / IP as the communication protocol, the RANGE header is used for the GET request sent from the client, and the start byte position and end of the data to be acquired A byte position is designated (for example, refer nonpatent literature 1). If an I frame of an MPEG moving image is designated as a range to be acquired, and I frames are continuously acquired and displayed, fast-forward playback can be realized. Further, if I frames are continuously acquired in the direction opposite to the playback direction, rewind playback can be realized. Furthermore, it is also possible to perform skip reproduction by designating an arbitrary start byte position and continuously acquiring data therefrom.

  In order to realize special playback, it is desirable to acquire management information related to the content configuration in advance on the client side. The management information describes the GOP (Group Of Pictures) and the byte position of the I frame constituting the content. If the content management information is acquired on the client side in advance, the byte position to be specified when performing special playback can be known. That is, it is possible to know the start byte position and end byte position of the I frame that should be specified when fast-forwarding and rewinding, and the start byte position of the GOP that should be specified when performing skip reproduction. Conversely, if the client does not have content management information, the byte position specified for special playback does not always match the start byte position of the GOP or I frame, so the received data is transferred to the decoder as it is. In such a case, there is a possibility that a problem such as an image being distorted may occur. In order to perform special reproduction without disturbing the image, it is necessary to acquire content management information from the server in advance and acquire data in GOP units or I frame units.

  In the method of acquiring the management information as described above and performing special playback, when content that is updated in real time, such as the content being recorded, is played over the network, the content management information must also be updated as needed. Special playback cannot be performed. If special playback is performed without updating the management information, for example, inconsistency occurs in which the content can be played back only up to 30 minutes even though the content is 60 minutes.

  However, in order to keep the latest management information on the client side at all times, the client must acquire the latest management information every time a GET request is transmitted, for example, and the server Processing such as regenerating management information for transmission to the client must be performed. These processes become a significant overhead for the acquisition of the originally necessary data. Therefore, it is expected that there will be a delay in content transmission and problems such as deterioration of responsiveness to user remote control operations.

  In such a case, as a solution, there is a method of restricting special reproduction operations in advance. In other words, the client side is restricted so that special reproduction is not performed on the content being recorded, and even if a special reproduction request is made by a user's remote control operation, the request is not accepted. The operation is limited only during the recording, and the special playback operation is accepted when the recording is completed. As a result, problems such as the occurrence of stress on the user due to the deterioration of the remote control operability can be prevented and the operability can be improved.

As a method for restricting access to content, a method of notifying information related to access restriction together with content list information has been proposed (for example, see Patent Document 1). In Patent Document 1, when there is content that cannot be accessed among the content held by the server, a flag indicating that access is not possible is embedded in the content list information transmitted to the client. On the client side, the content for which the flag is set is displayed in reverse video so that the user cannot select the content. In this way, operability is improved by preventing the user from performing unnecessary remote control operations.
"Hyper Text Transfer Protocol-HTTP / 1.1", RFC2616 JP 2005-135078 A

  However, since the above method is a method of embedding a flag when acquiring content list information, it is not suitable as a method for notifying a state that changes during content reproduction. In other words, if the recording is completed while the content being recorded on the server is being chased and played back via the network, the client cannot know that the recording has been completed unless the content list information is acquired again. , I can not know when the recording is complete. In this case, even when the operation is restricted for the content being recorded, there is a problem that the functionality for the user is greatly impaired because the restriction cannot be released at the timing when the recording is completed. In addition, inconsistency that the recording state of the content held on the client side does not match the actual recording state of the content on the server side, and when displaying the recording information on the client side, incorrect information is displayed. Will be communicated to the user.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a content transmission device and a content reception device capable of sequentially updating attribute information related to content. It is.

  In order to solve the above problems and achieve the above object, the content transmitting apparatus of the present invention includes one or more AV contents including at least either images or sounds, and one or a plurality of parts for each of the AV contents A content transmission device that divides the content into content and transmits the content according to a predetermined communication protocol, and generates a header of the communication protocol including attribute information of the AV content at the time of transmitting the partial content; A transmission means for transmitting the header of the communication protocol and the partial content is provided.

  With this configuration, even when the content attribute information changes during content transmission, the change of the attribute information can be notified to the receiving side.

  In the content receiving apparatus of the present invention, the AV content attribute information is included in the header of the communication protocol for the AV content including at least either image or sound, and the AV content is divided into one or more. A content receiving device that receives partial content according to a predetermined communication protocol, receiving means for receiving the header of the communication protocol and the partial content, and a point of time when the partial content is received from the header of the communication protocol And header analysis means for acquiring attribute information of the AV content.

  With this configuration, even when content attribute information changes during content reception, reception can receive a change in attribute information.

  The content transmission apparatus according to the present invention includes at least one AV content including at least one of an image and audio, and divides each AV content into one or a plurality of partial contents and transmits the content according to a predetermined communication protocol. A transmission device for generating a header of the communication protocol including attribute information of the AV content at the time of transmitting the partial content; and transmitting the header of the communication protocol and the partial content With the configuration including the transmission unit, the content attribute information can be transmitted, and even when the content attribute information changes during content transmission, the change of the attribute information can be notified to the reception side.

  In the content receiving apparatus of the present invention, the AV content attribute information is included in the header of the communication protocol for the AV content including at least either image or sound, and the AV content is divided into one or more. A content receiving device that receives partial content according to a predetermined communication protocol, receiving means for receiving the header of the communication protocol and the partial content, and a point of time when the partial content is received from the header of the communication protocol AV header attribute information can be analyzed, so that the AV content attribute information can be analyzed and received even when the content attribute information changes during content reception. Can receive changes in attribute information.

  In addition, the latest information on the content accumulated on the transmission side can be notified to the user viewing on the reception side.

  The content transmission apparatus according to the present invention includes at least one AV content including at least one of an image and audio, and divides each AV content into one or a plurality of partial contents and transmits the content according to a predetermined communication protocol. A transmission device for generating a header of the communication protocol including attribute information of the AV content at the time of transmitting the partial content; and transmitting the header of the communication protocol and the partial content And a transmission means.

  Thereby, the attribute information of the content can be transmitted, and even when the content attribute information changes during content transmission, the change of the attribute information can be notified to the receiving side.

  Further, the header generation means may include the attribute information of the AV content in the header of the communication protocol or not in the header according to the attribute information of the AV content at the time of transmitting the partial content. I do not care.

  Thereby, the content attribute information can be notified at the timing when the content transmitting device transmits the partial content, and the content attribute information can be acquired at the timing when the content receiving device receives the partial content. Since it is possible to process whether or not to include content attribute information according to the content of the attribute information, only necessary information can be sent.

  In addition, the content transmission device includes a request reception unit that receives a content acquisition request transmitted from the reception device, and the header generation unit is configured to change the communication protocol according to the content of the request received by the request reception unit. The AV content attribute information may or may not be included in the header of the communication protocol in the header.

  As a result, when a content acquisition request is received, the content attribute information can be included or not included depending on the content of the attribute information, so that only necessary information can be sent.

  Further, the transmission unit may be configured to transmit the header of the communication protocol and not transmit the partial content.

  Thereby, it is possible to periodically notify the attribute information of the content regarding the content other than the content being viewed on the receiving device side.

  The communication protocol may be HTTP, and the transmission unit may transmit a header including a POST request with CONTENT-LENGTH of 0 as the header of the communication protocol.

  By these, it can transmit using HTTP.

  The transmitting means may be configured to periodically transmit one or more or all of the one or more AV contents.

  As a result, even for content other than the content being viewed on the receiving device side, content attribute information can be periodically notified, and even when content is transmitted without being divided into partial content, the content attribute information is periodically updated. Can be transmitted.

  In addition, the transmission means may determine a timing for transmitting one or more or all of the one or more AV contents based on attribute information of the one or more AV contents. I do not care.

  As a result, processing of including or not including the attribute information of the content can be performed according to the content of the attribute information, so that only necessary information can be sent.

  In the content receiving apparatus of the present invention, the AV content attribute information is included in the header of the communication protocol for the AV content including at least either image or sound, and the AV content is divided into one or more. A content receiving device that receives partial content according to a predetermined communication protocol, receiving means for receiving the header of the communication protocol and the partial content, and a point of time when the partial content is received from the header of the communication protocol It is also possible to adopt a configuration comprising header analysis means for acquiring the attribute information of the AV content at.

  Thereby, the attribute information of the AV content can be analyzed, and the change of the attribute information can be received even when the content attribute information changes during the content reception.

  In addition, the content receiving device includes a request transmitting unit that specifies that the attribute information of the AV content is included in the header transmitted by the transmitting device to the transmitting device, and transmits a content acquisition request. It doesn't matter.

  Thus, when the content acquisition request is made, the attribute information of the content can be efficiently acquired when the attribute information is updated.

  Further, the request transmission unit transmits a content acquisition request by designating that the AV content attribute information is included or not included in the header based on the AV content attribute information acquired by the header analysis unit. You may make it the structure of doing.

  As a result, the content attribute information can be efficiently acquired when the content attribute information is updated.

  In addition, the request transmission unit may be configured to transmit a content acquisition request by designating acquisition of at least one or more AV contents of one or more AV contents held by the transmission apparatus. I do not care.

  As a result, the content attribute information can be included or notified according to the content of the attribute information, so that only necessary information can be received and the content attribute information has been updated. At that time, content attribute information can be efficiently acquired.

  The request transmission means selects a content to be acquired from at least one of the AV contents based on attribute information of the one or more AV contents held by the transmission device, and issues a content acquisition request. It may be configured to transmit.

  Thereby, it is possible to know the change of the attribute information other than the content that is not viewed.

  In addition, the request transmission unit may transmit the content acquisition request by transmitting the header of the communication protocol to the transmission device, specifying that the partial content is not transmitted.

  Accordingly, it is possible to notify that the attribute information of the content is included or not included according to the content of the attribute information, and thus it is possible to receive only necessary information.

  The communication protocol may be HTTP, and the request transmission unit may transmit a HEAD request.

  Thereby, it can receive using HTTP.

  Further, the request transmission means may be configured to periodically transmit a content acquisition request for acquiring at least one AV content among the one or more AV contents.

  Accordingly, the content attribute information can be periodically received even for content other than the content being viewed on the receiving device side.

  Further, the content receiving apparatus may be configured to include a display unit that displays attribute information of the AV content.

  Thereby, the attribute information of the acquired content can be notified to the user at any time.

  Further, the content receiving device includes attribute information receiving means for receiving attribute information of the AV content, and the request transmitting means receives attribute information of at least one AV content among the one or more AV contents. An attribute information acquisition request for acquisition may be transmitted periodically.

  Thereby, the attribute information of the acquired content can be notified to the user at any time.

(Embodiment)
The best mode for carrying out the present invention will be described below with reference to the drawings.

  First, a configuration diagram of a network in the embodiment will be described with reference to FIG.

  FIG. 1 is a diagram illustrating a connection example of a content transmission device and a content reception device in the embodiment. FIG. 1 can be broadly classified into two systems. The first is a system for television broadcasting via a coaxial cable, and a center device 100 and a content transmission device 200 are connected via a broadcasting network 10. The second is a home LAN via an Ethernet (registered trademark) cable, and the content transmission device 200 and the content reception device 300 are connected via the communication network 20. TCP / IP is used as the communication protocol of the communication network 20.

  The center device 100 is installed in a television broadcast base station, and is a server or the like that distributes video content. The content transmitted from the center device 100 is transmitted to each terminal connected to the broadcast network 10, and each terminal can view and record the content.

  The content transmission device 200 is, for example, an STB (set top box), HDD recorder, or the like having a function of receiving and demodulating a broadcast from a base station. Further, the content transmission device 200 has a function of performing packet communication via a home LAN. The content transmission device 200 can transmit content accumulated by recording a program or the like via the communication network 20.

  The content receiving device 300 is an STB, a television, or the like that has a function of performing packet communication via a home LAN. The content receiving apparatus 300 can view and store the content received via the communication network 20.

  For the sake of simplicity, the content transmitting apparatus 200 and the content receiving apparatus 300 have different functions. However, they may not have a difference in performance and function.

  Next, the configuration of content transmission apparatus 200 in the embodiment will be described with reference to FIG.

  FIG. 2 is a diagram illustrating a configuration of the content transmission device 200 according to the embodiment. The content transmission apparatus 200 includes a tuner unit 201, a demodulation unit 202, a content storage unit 203, an attribute information generation unit 204, a management information generation unit 205, a recording control unit 206, a transmission control unit 207, and a reception unit. 208, a header generation unit 209, and a transmission unit 210.

  When a user operating the content transmission apparatus 200 records a broadcast program, the content broadcast from the broadcast network 10 is received via the tuner unit 201, the signal is demodulated by the demodulation unit 202, and the content is stored. Accumulate in means 203. The content storage unit 203 is a medium such as an HDD or a DVD. Also, when content selected by the user by VOD (video on demand) or the like is stored, the content distributed via the broadcast network 10 is received and demodulated and stored in the content storage unit 203. These recording controls are performed by the recording control means 206. The recording method may be automatic recording that automatically starts (and ends) recording at a time designated by reservation, or manual recording that is performed manually by a user.

  The content transmission device 200 has a function of transmitting accumulated content via a network. Here, a PULL type, that is, a model in which the transmission side transmits content based on a request from the reception side is assumed.

  First, the receiving unit 208 receives a request from a receiving terminal. If the received request is a request for acquiring attribute information related to the content, the attribute information generation unit 204 creates the attribute information of the content as a list and transmits the list via the transmission unit 210. The attribute information refers to information related to the content content such as the title name of the content, the recording start time, the recording end time, the recording time, the channel number, and the recording mode.

  If the received request is a request for acquiring content management information, the management information generation unit 205 creates content management information and transmits the content management information via the transmission unit 210. The management information refers to information regarding the configuration of content data. More specifically, the MPEG video content configuration information is described with respect to the internal configuration of the content, such as GOP (Group Of Pictures) and byte position information of the I frame.

  If the received request is a request for acquiring the data of the content itself, the content data is read from the content storage unit 203. Here, assuming HTTP (Hyper Text Transfer Protocol) as a communication protocol for content transmission, the header generation unit 209 generates an HTTP header. At this time, the header generated by the header generation unit 209 includes attribute information of the content to be transmitted. The transmission unit 210 transmits the content by adding the header created by the header generation unit 209 to the content data read from the content storage unit 203. These transmission controls are performed by the transmission control means 207.

  Next, the configuration of content receiving apparatus 300 in the embodiment will be described with reference to FIG.

  FIG. 3 is a diagram illustrating a configuration of the content receiving device 300 according to the embodiment. The content receiving apparatus 300 includes an input unit 301, a reproduction control unit 302, a transmission unit 303, a reception unit 304, a header analysis unit 305, an attribute information extraction unit 306, a management information analysis unit 307, and a decryption unit 308. And an output unit 309.

  When a user who wants to view content performs a remote control operation, a command is input via the input unit 301. First, in order to know the content accumulated in the terminal on the transmission side, attribute information related to the content is acquired. The attribute information includes information such as the title name of the content and the recording start time. When the attribute information acquisition request is transmitted via the transmission unit 303, the attribute information is received via the reception unit 304. Further, attribute information relating to the content is extracted via the attribute information extracting unit 306 and output to the output unit 309. The output unit 309 is a monitor or the like that displays an image. Here, information about the contents is displayed as a list on the screen.

  Next, the user selects content to view from the content list. Prior to content acquisition, management information about the content is acquired. The management information acquisition request is transmitted via the transmission unit 303, and the management information transmitted from the transmission side is received via the reception unit 304. By analyzing the received management information in the management information analysis means 307, information related to the internal structure of the content can be known. Special reproduction can be realized by designating a range of data to be acquired based on information obtained by the management information analysis unit 307.

  Next, the selected content is acquired from the transmission side. The content acquisition request to the transmission side is transmitted via the transmission unit 303. The content transmitted from the transmitting terminal is received via the receiving unit 304. Since the data received by the receiving unit 304 includes an HTTP header, the header analyzing unit 305 analyzes the HTTP header part. When attribute information is included in the header, the attribute information is extracted by the attribute information extraction unit 306 and notified to the reproduction control unit 302 and the output unit 309. The reproduction control unit 302 changes the operation restriction according to the content attribute information. For example, only normal playback is permitted for content being recorded, and special playback operations are prohibited. The output means 309 displays content attribute information and notifies the user of the information.

  On the other hand, the data portion of the content separated by the header analysis unit 305 is decrypted by the decryption unit 308 and then output to the output unit 309. Thereby, the received content can be output as video or audio. These controls are performed in the reproduction control means 302. Here, the decoding unit 308 is a decoder or the like that decodes data. The output unit 309 may be a speaker that outputs audio, or may be a storage medium such as an HDD or a DVD for recording content.

  Next, a procedure for notifying attribute information of the content being played back in the embodiment will be described with reference to the drawings.

  FIG. 7 shows a list of attribute information of all contents held by the content transmitting apparatus 200 at a certain point in time.

  The content transmission apparatus 200 holds information such as the current state, recording date, recording start time, recording end time, recording time, channel number, title name, URI (Uniform Resource Identifier) as attribute information related to the content. These are managed for each content by giving an ID. The current state indicates whether the content has been recorded or is being recorded. Here, it is assumed that the contents ID1 to ID3 have been recorded, and only the contents ID4 are being recorded. The URI indicates the storage location of the content. These pieces of information are generated by the attribute information generation unit 204.

  FIG. 4 shows a screen when content list information is displayed in the content receiving device 300.

  As shown in FIG. 4, the screen 500 displayed by the output unit 309 of the content receiving device 300 includes a preview display unit 501, a recording time display unit 502, a current time display unit 503, a recording information display unit 504, and a recording date display unit 505. The recording start time display unit 506, the channel number display unit 507, and the title name display unit 508 are divided into a plurality of parts.

  Now, the content receiving apparatus 300 acquires the attribute information of all the contents from the content transmitting apparatus 200, acquires the management information related to the fourth content displayed in the list, and is receiving the data of the fourth content. Shall. If the attribute information acquired from the content transmitting apparatus 200 is as shown in FIG. 7, the recording time display unit 502, the recording information display unit 504, the recording date display unit 505, the recording start time display unit 506, and the channel number display of FIG. The contents displayed in the section 507 and the title name display section 508 correspond to the recording time, current state, recording date, recording start time, channel number, and title name of FIG. The preview display unit 501 plays the focused content on a small screen. Here, the video of the fourth content being acquired from the content transmission device 200 is displayed on a small screen. The current time display unit 503 displays the current time based on a clock held inside the content receiving device 300.

  Here, the content previewed by the content receiving device 300 is the content being recorded by the content transmitting device 200. In this way, a method of viewing a program while shifting the time while recording the program is called chasing playback or time shift playback. Here, the content that is being recorded by the content transmitting apparatus 200 is chased and reproduced on the preview screen from the content receiving apparatus 300 via the network.

  FIG. 13 shows the exchange of packets on the network during chasing playback.

  First, the content receiving device 300 transmits a message requesting content transmission to the content transmitting device 200. The message to be transmitted is an HTTP GET request, which is indicated by message # 1 in FIG. Message # 1 includes a RANGE header, and makes a request by specifying the start byte position and end byte position of the content data to be acquired. Here, the 0th byte to the 99999th byte are designated and acquired. The byte position designated here is determined based on the management information acquired prior to the acquisition of the content. Here, it is assumed that a GET request is transmitted for each GOP, and the 0th byte specified here is the start byte position of the first GOP, and the 99999th byte is the end byte position.

  Furthermore, a header of “X-RECORDING-STATE: request” is added to the message # 1 in addition to the normal HTTP header. This requests the content transmission apparatus 200 to add a header related to the recording information to the response message.

  The content transmitting apparatus 200 that has received the message # 1 transmits an HTTP response as shown in message # 2 of FIG. 9 as a response. In addition to the normal HTTP header, a header of “X-RECORDING-STATE: recording” is added to the message # 2. This notifies the content receiving device 300 that the content being transmitted is currently being recorded. The content receiving device 300 can know that the currently reproduced content is being recorded by extracting such a header. The content transmitting apparatus 200 adds a header indicating the recording information to the response message only when the received request message includes the header “X-RECORDING-STATE: request”.

  The content transmitting apparatus 200 continues to transmit content data. This is to transmit the content in the range specified in the RANGE header of message # 1. The content receiving apparatus decodes this and outputs the received content video on the preview screen.

  Similarly, the message # 3 is transmitted from the content receiving device 300, and the content transmitting device 200 that receives the message # 3 transmits the message # 4 and content data. Message # 3 includes a header “X-RECORDING-STATE: request” indicating acquisition of recording information, and message # 4 includes a header “X-RECORDING-STATE: recording” indicating recording information of content. Yes. While the content being transmitted is being recorded, the message transmitted by the content transmitting apparatus 200 includes a header indicating that the content is being recorded.

  Here, it is assumed that recording ends at a certain time. Specifically, as shown in FIG. 7, the recording of the content ends at 21:00. At this time, content transmitting apparatus 200 transmits message # 6 to received message # 5. The message # 6 includes a header “X-RECORDING-STATE: complete”. This notifies that the recording of the content being transmitted has been completed.

  The content receiving device 300 that has received the message # 6 analyzes the received message and knows that the recording has ended when it detects that the header “X-RECORDING-STATE: complete” is included. it can. At this time, the information displayed on the output means 309 is updated. For example, in the case of the display screen as shown in FIG. 4, the mark indicating that recording is being performed, which is displayed on the recording information display unit 504, is deleted. As a result, the user viewing the screen can immediately know that the recording has been completed.

  Also, the playback control unit 302 switches operation restrictions based on content attribute information. Specifically, the content being recorded is allowed only normal playback and special playback is prohibited. This is because it is necessary to acquire management information of the content in advance to perform special playback, and the management information of the content being recorded is updated as needed. Considering the fact that information needs to be updated and acquiring management information from time to time is a significant overhead, so that responsiveness is expected to deteriorate. .

  When a skip playback request is made by a user operation, a skip playback command is sent from the input unit 301 to the playback control unit 302. Here, the attribute information acquired by the attribute information extraction unit 306 is referred to. If the content is being recorded, the requested skip playback command is invalidated. At this time, the user may be notified by displaying on the screen that the command has not been accepted. On the other hand, if the content recording is completed, the skip reproduction request is converted into a content acquisition request and transmitted via the transmission unit 303. As described above, it is possible to immediately detect the completion of recording by analyzing the header of the response message. Therefore, the special reproduction prohibition restriction can be released at the timing when the content recording is completed.

  The content of updating the screen display when the end of recording is detected is not limited to the recording information display unit 504. For example, the time displayed on the recording time display unit 502 may be updated simultaneously. In this case, the display is updated from the state displayed as 2 hours 45 minutes to 3 hours 00 minutes. The user can know the latest attribute information regarding the content.

  In the present embodiment, the header “X-RECORDING-STATE” is used as a method for acquiring the information of the content being recorded. However, this is merely an example, and the header name, description format, etc. There are no restrictions.

  Further, the attribute information embedded in the header of the communication protocol is not limited to information indicating whether recording is in progress or not. For example, the recording time may be notified. If the recording time is notified, the time displayed on the recording time display unit 502 can be updated as needed at the timing of receiving the partial content. Alternatively, when the recording end time is changed due to an extension of the recording time, a notification to that effect may be made.

  In the present embodiment, the attribute information embedded in the header of the communication protocol is not limited to that relating to recording. For example, when the title name of the content is updated during content reproduction, the updated title name may be notified. In the present embodiment, it is assumed that the attribute information embedded in the header of the communication protocol only needs to change during content transmission.

  In this embodiment, the information to be embedded in the communication protocol header may be a description that directly describes the attribute information of the content, or only notification that the attribute information has been updated. It may be. The notification of only the attribute information update is realized, for example, by setting a flag indicating that the attribute information has been updated. The content receiving apparatus that has detected that the flag is set can acquire the latest attribute information by transmitting an attribute information acquisition request to the content transmitting apparatus and acquiring attribute information about the content again.

  In the present embodiment, the request message transmitted from the content receiving apparatus 300 is added with a header requesting that the response includes a header related to attribute information. However, depending on the acquired attribute information, the header is added. May or may not be added. For example, when content recording is completed in the content transmission apparatus 200, it is not updated even if information related to recording is acquired thereafter. Therefore, it is determined that acquisition of recording information is unnecessary, and a header is included in the request message. May not be added.

  In the present embodiment, the form of screen display is not limited. For example, not only the preview screen as shown in FIG. 4 but also a normal playback screen as shown in FIG. In FIG. 5, a screen 500 includes a current time display unit 503, a content display unit 509, and an information notification unit 510. When the content recording is finished while viewing the content on the screen as shown in FIG. 5, the information notification unit 510 may notify the completion of the recording. In the present embodiment, the notification format for notifying that the attribute information has been updated is not limited.

  Next, a procedure for notification of attribute information of content that is not being reproduced in the present embodiment will be described.

  Consider a case in which the content transmission apparatus 200 holds content and content attribute information as shown in FIG. 8 and preview playback is performed from the content reception apparatus 300 on the screen as shown in FIG. At this time, the content being recorded in the content transmitting apparatus 200 is the fifth content, and the content being preview reproduced in the content receiving apparatus 300 is the fourth content.

  The content receiving device 300 performs communication as shown in FIG. 14 during content reception in order to acquire information on content other than the content being viewed. In FIG. 14, the messages transmitted by the content receiving apparatus 300 are as shown in message # 11, message # 13, message # 15, and message # 17 in FIG. These are obtained by transmitting HTTP HEAD requests to different contents. These messages include a header “X-RECORDING-STATE: request”, and inquire whether each content is being recorded.

  The content transmitting apparatus 200 that has received the request message from the content receiving apparatus 300 returns a corresponding message as a response. Since message # 11, message # 13, and message # 15 are requests for recorded content, message # 12, message # 14, and message # 16, which are responses to the message # 11, message # 13, and message # 15, have headers “X-RECORDING-STATE”. : Complete ”. On the other hand, since the message # 17 is a request for the content being recorded, the response message # 18 includes a header “X-RECORDING-STATE: recording”. Thereby, the content receiving apparatus 300 can determine that only the fifth content is being recorded.

  Thereafter, the content receiving apparatus 300 periodically transmits an HTTP HEAD request to the content transmitting apparatus 200 to inquire about the recording state. If the header of the response message changes midway, the end of recording can be detected at that time. When the end of recording is detected, the display on the screen is updated at that time, so that the user can always know the latest content information.

  Note that such transmission of the request message may be performed for all the contents held by the content transmission apparatus 200 or only for some contents. For example, a message may be transmitted only for the content being recorded without transmitting a message for the content for which recording has been completed. The request message may be transmitted periodically, or the timing for transmitting the request message may be determined based on the acquired attribute information. For example, information related to the recording end time may be acquired from the content transmission device, and a request message may be transmitted at the recording end time or a time near the recording end time.

  Further, in the present embodiment, a PULL type model using an HTTP GET request is assumed for content acquisition. However, even in a PUSH type model using an HTTP POST request, attribute information is also sequentially obtained. It is possible to update.

  FIG. 15 shows the exchange of packets when the PUSH type content being recorded is transmitted.

  First, the content transmission device 200 transmits a message requesting content transmission to the content reception device 300, and also transmits content data. The message to be transmitted is an HTTP POST request, which is indicated by message # 21 in FIG. Message # 21 includes a header called X-RANGE, which specifies the start byte position and end byte position of the content data to be transmitted. Here, the 70000th byte to the 799999th byte are designated and transmitted. The byte position specified here may specify a GOP boundary based on content management information, or may arbitrarily set a value.

  Further, in addition to the normal HTTP header, a header of “X-RECORDING-STATE: recording” is added to the message # 21. This notifies the content receiving device 300 that the content being transmitted is currently being recorded. The content receiving device 300 can know that the currently received content is being recorded by extracting such a header.

  The content transmitting apparatus 200 continues to transmit content data. This is to transmit content in the range specified in the X-RANGE header of message # 21. When the content receiving apparatus 300 completes the reception of the content in the designated range, the content receiving apparatus 300 transmits a response message # 22 to the content transmitting apparatus 200.

  Here, it is assumed that recording ends at a certain time. At this time, the content transmitting apparatus 200 transmits message # 23. The message # 23 includes a header “X-RECORDING-STATE: complete”. This notifies that the recording of the content being transmitted has been completed.

  The content receiving device 300 that has received the message # 23 analyzes the received message and knows that the recording has ended when it detects that the header “X-RECORDING-STATE: complete” is included. it can. When the content receiving device 300 completes the reception of the content to be continuously transmitted, the content receiving device 300 transmits a response message # 24 to the content transmitting device 200.

  On the other hand, the procedure for notifying content attribute information not being transmitted is as follows.

  The content transmission apparatus 200 performs communication as shown in FIG. 16 during content transmission in order to notify information on content other than the content being transmitted. In FIG. 16, the messages transmitted by the content transmitting apparatus 200 are as shown in message # 31, message # 33, message # 35, and message # 37 in FIG. In these, POST requests with CONTENT-LENGTH set to 0 are transmitted for different contents. These messages include a header “X-RECORDING-STATE” to notify whether each content is being recorded or has been recorded.

  Since message # 31, message # 33, and message # 35 are all recorded content transmission requests, they include a header “X-RECORDING-STATE: complete”. On the other hand, since the message # 37 is a request for transmitting the content being recorded, the message # 37 includes a header “X-RECORDING-STATE: recording”. Thereby, the content receiving apparatus 300 can determine that only the fifth content is being recorded. In these requests, CONTENT-LENGTH is 0, and content data is not actually transmitted / received. The content receiving apparatus 300 that has received the request returns message # 32, message # 34, message # 36, and message # 38 as response messages for each message.

  Thereafter, the content transmission device 200 periodically transmits an HTTP POST request to the content reception device 300 to notify the recording state. If the message header changes during the process, the end of recording can be detected at that time. When the end of recording is detected, the display on the screen is updated at that time, so that the user can always know the latest content information.

  Note that such message transmission may be performed for all contents held by the content transmission apparatus 200 or only for some contents. For example, a message may be transmitted only for the content being recorded without transmitting a message for the content for which recording has been completed. Further, the message may be transmitted periodically, or the timing for transmitting the message may be determined based on the attribute information. For example, a request message may be transmitted at the recording end time or a time near the recording end time based on the information regarding the recording end time.

  Further, in the present embodiment, the content receiving device 300 acquires content by dividing it into partial contents such as specifying for each GOP based on the acquired management information. It is not limited to the method of dividing into. For example, if the content transmitting apparatus does not transmit management information, the content transmitting apparatus 300 cannot acquire the management information and cannot know the start byte position and end byte position of the GOP. In such a case, the content receiving apparatus 300 may arbitrarily specify the start byte position and the end byte position, or may acquire all the content data at once without specifying the range.

  When all the content data is acquired at once, the content transmission apparatus periodically transmits an attribute information acquisition request during content reception as shown in FIG. When there is a change in the content attribute information, such as when the recording of the content being recorded is completed, the content of the acquired attribute information is also changed, so the content receiving device 300 detects that the information has been updated. be able to.

  Note that the transmission of the attribute information acquisition request may be performed for all the contents held by the content transmission apparatus, or may be performed for only some contents. For example, a request may be transmitted only for content that is being recorded without transmitting a request for content that has been recorded. The request may be transmitted periodically, or the timing for transmitting the request may be determined based on the attribute information. For example, the request may be transmitted at the recording end time or a time near the recording end time based on the information regarding the recording end time.

  The content transmission device and content reception device of the present invention are useful as an HDD recorder, STB, or the like that transmits and receives AV content via a network.

Network configuration diagram in the embodiment Configuration diagram of content transmission apparatus in embodiment Configuration diagram of content receiving apparatus according to an embodiment The figure which shows the preview screen of the content in recording in embodiment The figure which shows the reproduction | regeneration screen of the content in embodiment The figure which shows the preview screen of the recorded content in embodiment The figure which shows the attribute information of the content in embodiment The figure which shows the attribute information of the content in embodiment The figure which shows the message of attribute information acquisition in embodiment The figure which shows the message of attribute information acquisition in embodiment The figure which shows the message of the attribute information notification in embodiment The figure which shows the message of the attribute information notification in embodiment The figure which shows the sequence of attribute information acquisition in embodiment The figure which shows the sequence of attribute information acquisition in embodiment The figure which shows the sequence of the attribute information notification in embodiment The figure which shows the sequence of the attribute information notification in embodiment The figure which shows the sequence of attribute information acquisition in embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Broadcast network 20 Communication network 100 Center apparatus 200 Content transmission apparatus 201 Tuner means 202 Demodulation means 203 Content storage means 204 Attribute information generation means 205 Management information generation means 206 Recording control means 207 Transmission control means 208 Reception means 209 Header generation means 210 Transmission Means 300 Content receiving apparatus 301 Input means 302 Playback control means 303 Transmission means 304 Reception means 305 Header analysis means 306 Attribute information extraction means 307 Management information analysis means 308 Decoding means 309 Output means 500 Screen 501 Preview display section 502 Recording time display section 503 Current time display section 504 Recording information display section 505 Recording date display section 506 Recording start time display section 507 Channel number display section 508 Title name display section 509 Content display Part 510 Information notification part

Claims (23)

A content transmitting apparatus that includes at least one AV content including at least one of an image and audio, divides each AV content into one or a plurality of partial contents, and transmits the AV content according to a predetermined communication protocol,
Header generating means for generating a header of the communication protocol including attribute information of the AV content at the time of transmitting the partial content;
A content transmission apparatus comprising: a transmission unit configured to transmit a header of the communication protocol and the partial content. The header generation means includes the attribute information of the AV content in the header of the communication protocol or does not include it in the header according to the attribute information of the AV content at the time of transmitting the partial content. Item 2. The content transmission device according to Item 1. The content transmission device includes request reception means for receiving a content acquisition request transmitted from a reception device,
The header generation unit includes the attribute information of the AV content in the header of the communication protocol or does not include the header in the communication protocol according to the content of the request received by the request reception unit. The content transmission apparatus according to claim 2. The content transmission apparatus according to claim 1, wherein the transmission unit transmits a header of the communication protocol and does not transmit the partial content. The communication protocol is HTTP,
5. The content transmission apparatus according to claim 4, wherein the transmission unit transmits a header including a POST request in which CONTENT-LENGTH is 0 as a header of the communication protocol. 6. The content transmission apparatus according to claim 1, wherein the transmission unit periodically transmits one or more or all of the one or more AV contents. The transmission means determines a transmission timing of one or more or all of the one or more AV contents based on attribute information of the one or more AV contents. 6. The content transmission device according to 6. For AV content including at least one of image and audio, attribute information of the AV content is included in a header of a communication protocol, and the AV content is a partial content divided into one or a plurality of predetermined communication protocols. A content receiving device for receiving according to:
Receiving means for receiving a header of the communication protocol and the partial content;
A content receiving apparatus comprising: header analysis means for acquiring attribute information of the AV content at the time of receiving the partial content from the header of the communication protocol. The content receiving apparatus includes request transmitting means for transmitting a content acquisition request by designating the header transmitted by the transmitting apparatus to include attribute information of AV content to the transmitting apparatus. The content receiving device according to claim 8. The request transmission unit transmits a content acquisition request by designating that the attribute information of the AV content is included or not included in the header based on the attribute information of the AV content acquired by the header analysis unit. The content receiving apparatus according to claim 9. The request transmission means transmits a content acquisition request by designating acquisition of at least one or more AV contents of one or more AV contents held by the transmission apparatus. The content receiving device according to claim 9 or claim 10. The request transmission means selects an AV content to be acquired from at least one of the AV contents based on attribute information of the one or more AV contents held by the transmission device, and transmits a content acquisition request. The content receiving apparatus according to claim 11. 9. The request transmission unit transmits a content acquisition request to the transmission device by transmitting a header of the communication protocol, specifying that the partial content is not transmitted. Content receiving device. The content receiving apparatus according to claim 13, wherein the communication protocol is HTTP, and the request transmission unit transmits a HEAD request. 9. The content reception according to claim 8, wherein the request transmission unit periodically transmits a content acquisition request for acquiring at least one AV content among the one or more AV content. apparatus. The content receiving device includes display means for displaying attribute information of the AV content,
The header analysis means analyzes the communication protocol header when the reception means receives the communication protocol header and partial content,
16. The content receiving apparatus according to claim 9, 13, or 15, wherein the display means displays attribute information acquired by the header analysis means as needed. The content receiving device includes display means for displaying attribute information of the AV content,
The header analysis means analyzes the communication protocol header at the time when the reception means receives the communication protocol header and partial content in the reception means,
17. The content receiving apparatus according to claim 8, wherein the display means displays as needed based on the attribute information acquired by the header analysis means. The content receiving device includes attribute information receiving means for receiving attribute information of the AV content, and the request transmitting means acquires attribute information of at least one AV content among the one or more AV contents. The content receiving apparatus according to claim 8, wherein an attribute information acquisition request for transmitting is periodically transmitted. 19. The content receiving apparatus according to claim 18, wherein the request transmission unit selects whether or not to transmit a request based on the attribute information received by the attribute information reception unit. 19. The content receiving apparatus according to claim 18, wherein the request transmitting unit determines a timing for transmitting a request based on attribute information received by the attribute information receiving unit. The request transmission unit selects an AV content for obtaining attribute information from the one or more AV contents based on the attribute information received by the attribute information reception unit, and transmits the request. Item 21. The content receiving device according to Item 18. The content receiving device includes display means for displaying attribute information of AV content,
The content receiving apparatus according to claim 18, wherein the display means displays the attribute information received by the attribute information receiving means as needed. The content receiving device includes display means for displaying attribute information of AV content,
The content receiving apparatus according to claim 22, wherein the display unit updates or does not update the content of the attribute information based on the attribute information received by the attribute information receiving unit.

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