JP2008263412A - Content receiving apparatus and content transmitting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent preview playback of a content from being continued and a network band from being uselessly occupied when a user does not view the content in a content receiving apparatus for reproducing and displaying the content received through a network. <P>SOLUTION: In displaying a received content by a preview playback format in the content receiving apparatus having a plurality of reproduction formats including the preview reproduction format and a full screen reproduction format, the reception of the content is stopped after a fixed time elapses from the start of the content reception. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  In recent years, exchange of contents via a network has been actively performed. If a home LAN is constructed, AV content stored in, for example, a personal computer or a hard disk (hereinafter referred to as HDD) recorder can be streamed from a television or DVD player in another room. Hereinafter, a device that stores and transmits content in this manner is referred to as a server, and a device that receives and plays back content is referred to as a client.

  The procedure for viewing content via the network is as follows.

  First, the client searches for a server connected to the network. When UPnP (Universal Plug and Play) is used as a communication protocol, an M-SEARCH command is used for device search. Since the server that has received the M-SEARCH request returns an M-SEARCH response to the client, it is possible to find a server connected in the network.

  When a plurality of servers are found, one device for acquiring content is selected from the found servers. The selection here may be selected by the user who operates the client, or may be automatically selected by the client device.

  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. As the attribute information related to the content, for example, in the case of a recorded content, there are information such as a program name of a recorded broadcast program, a recording start time, a recording end time, a recording time, a channel number, and a recording mode. When UPnP is used as the communication protocol, the content list information acquisition request corresponds to a Browse action request of CDS (Content Directory Service). In UPnP, content attribute information is described in an XML (Extensible Markup Language) format, and is notified from the server to the client as a Browse action response.

  On the client side, the acquired content list information is displayed on the monitor screen, and the user selects the content that he / she wants to see and starts normal playback. The content reproduction request from the user is transmitted to the server as a content acquisition request from the client. When HTTP (Hyper Text Transfer Protocol) is used as the communication protocol, the content acquisition request corresponds to an HTTP GET request. The server that has received the content acquisition request transmits the actual data of the content to the client. In HTTP, these are transmitted as responses to GET requests. The client receiving the response decrypts the data, so that the client can view the content.

  In a recording / playback device such as an HDD recorder, when displaying content list information, it is generally performed to display content video by simultaneously performing preview playback on a sub-screen. An example of the preview screen is shown in FIG. In the example of FIG. 1, the content stored in the HDD is displayed as a list on the right side, and the video of the focused content (selected) is displayed and reproduced on the left preview screen. This is intended to allow users to easily select the content they want to view from the content list by actually displaying the video content as well as information such as the title name and recording date and time. It is.

  Thereafter, when the user wants to view the selected content, the playback is switched from preview playback to full screen playback by pressing a playback start button on the remote controller. An example of full screen playback is shown in FIG. The content of the displayed video is the same as in preview playback, but the display size is different, such as when the video is displayed on the full screen, and it is displayed in a state suitable for viewing a program.

  When preview playback is performed via a network, it is necessary to transmit a content acquisition request from a client and to transmit content data from a server that has received the request, as in the case of performing full-screen playback. This is a process performed in the same manner regardless of whether the display form on the client is preview playback or full screen playback. In other words, focusing on preview playback, the same amount of content data is displayed on the network as in full-screen playback, even though the displayed screen size is small compared to full-screen playback. Will be flowing. This is inefficient from the viewpoint of network resources.

In terms of effective use of network resources, several methods for converting the bit rate of content to be transmitted have been proposed (for example, Patent Document 1). If applied to the previous example, for example, in the case of full-screen playback, the content data is transmitted as it is, and in the case of preview playback, the content is converted to a low bit rate and then transmitted. Since the size of the screen displayed in the preview playback is small, even if the video is roughened by reducing the rate, the user hardly notices the change. That is, the load on the network can be reduced without making the user feel uncomfortable.
JP 2005-318057 A

  However, even if the network load is reduced by converting the bit rate of the content to be transmitted, the content of the constant bit rate is still transmitted. In other words, a certain band is occupied more or less during preview reproduction.

  On the other hand, preview playback is performed on the content list display screen as shown in FIG. For example, a case where the user leaves the place with the screen displayed and is left as it is for a long time can be easily considered. Even in such a case, with the above method, a certain network bandwidth is unnecessarily occupied. That is, there is a problem that, when left in the preview playback state, the network bandwidth is unnecessarily occupied regardless of whether the user is actually viewing or not.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a content receiving apparatus and a content transmitting apparatus that prevent occupation of useless network bandwidth.

In order to solve the above problems and achieve the above object, the content receiving device of the present invention provides:
A content receiving device for playing back and displaying content received via a network,
The content receiving device includes display means for displaying the received content,
The display means has a plurality of display forms in which the size of a window for displaying at least the received content video is different,
When displaying a video in a specific display form among the plurality of display forms, reception of content is stopped.

In addition, the content receiving device
Timer means for detecting that a specific time has elapsed,
The timer means detects that a predetermined time has elapsed since the start of content reception, and stops receiving the content.

In addition, the content receiving device
Viewing information specifying means for specifying whether or not the content displayed by the display means is being viewed;
The viewing information specifying means stops receiving the content when it is specified that the content is not viewed.

In addition, the content receiving device
An input means for accepting external input operations;
Timer means for detecting that a specific time has elapsed,
The viewing information specifying means includes
The timer means specifies that the content is not viewed when the input operation from the input means has not been performed for a certain period of time.

The content transmission device of the present invention is a content transmission device that transmits content to a content reception device via a network.
The content receiving apparatus has a plurality of display forms in which the size of a window for displaying at least the video of the received content is different,
The content transmission device includes display information acquisition means for acquiring information related to a display form of the content reception device,
When the information acquired by the display information acquisition means indicates a specific display form, content transmission is stopped.

In addition, the content transmission device includes:
Timer means for detecting that a specific time has elapsed,
The timer means detects that a predetermined time has elapsed since the start of content transmission, and stops the content transmission.

  With the configuration described above, content transmission is automatically interrupted when left in the preview playback state, so that the network load can be eliminated.

  The present invention can reduce the load on the network with respect to transmission / reception of content via the network, particularly by eliminating unnecessary data transmission when preview reproduction is performed.

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

(Embodiment)
First, a network configuration diagram according to the embodiment of the present invention will be described with reference to FIG.

  FIG. 3 is a diagram illustrating a connection example of the content transmission device and the content reception device according to the embodiment of the present invention. A content transmission device 100 and a content reception device 200 are connected via a communication line 10 in a home LAN via an Ethernet (registered trademark) cable. TCP / IP is used as the communication protocol of the communication line 10.

  The content transmission apparatus 100 is, for example, an STB (Set Top Box), an HDD recorder or the like having a function of receiving and demodulating a broadcast from a base station. Further, the content transmission device 100 has a function of performing packet communication via a home LAN. The content transmitting apparatus 100 can transmit content accumulated by recording a program or the like via the communication line 10.

  The content receiving apparatus 200 is an STB, a television, or the like that has a function of performing packet communication via a home LAN. The content receiving device 200 can view and store the content received via the communication line 10.

  In the embodiment of the present invention, HTTP is used as a communication protocol for transmitting content data. The content receiving apparatus 200 transmits an HTTP GET request as a content acquisition request. The content transmitting apparatus 100 that has received the request transmits data such as management information and content together with the HTTP response. Also, UPnP is used for transmission / reception of attribute information related to the content such as the recording time and title name of the content.

  Next, the configuration of content transmission apparatus 100 according to the embodiment of the present invention will be described with reference to FIG.

  FIG. 4 is a diagram showing a configuration of content transmission apparatus 100 in the embodiment of the present invention. The content transmission apparatus 100 includes a transmission unit 101, a reception unit 102, a transmission control unit 103, a management information generation unit 104, an attribute information generation unit 105, and a content storage unit 106.

  The content storage unit 106 is a readable / writable recording medium such as an HDD or a DVD. The content storage unit 106 stores recorded broadcast programs, content purchased by the user through VOD (video on demand), and the like.

  The content transmission apparatus 100 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 will be described as an example.

  First, the receiving unit 102 receives a request from a client. If the received request is a request for acquiring attribute information related to the content (that is, a UPnP Browse action request), the attribute information generation unit 105 creates the attribute information of the content as a list and transmits it via the transmission unit 101. To do. 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. Here, the attribute information is described in the XML format and is transmitted as a Browse action response.

  If the received request is a request for acquiring content management information (that is, an HTTP GET request), the management information generation unit 104 creates content management information and transmits the content management information via the transmission unit 101. 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 data of the content itself (that is, an HTTP GET request), the content data is read from the content storage unit 106. Whether the request is for management information or content data is identified by a URI (Uniform Resource Identifier) included in the GET request. The transmission unit 101 transmits the content data read from the content storage unit 106 as an HTTP response. These transmission controls are performed by the transmission control unit 103.

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

  FIG. 5 is a diagram showing a configuration of content receiving apparatus 200 in the embodiment of the present invention. The content receiving apparatus 200 includes a transmission unit 201, a reception unit 202, a reproduction control unit 203, a management information analysis unit 204, an attribute information analysis unit 205, a decryption unit 206, an output unit 207, and an input unit 208. Is provided.

  When a user who wants to view content performs a remote control operation, a command is input via the input unit 208. First, in order to know the content stored in the server, attribute information about the content is acquired. When an attribute information acquisition request (that is, a Browse action request) is transmitted via the transmission unit 201, the attribute information (that is, a Browse action response) is received via the reception unit 202. Since the received attribute information is described in the XML format, the attribute information analysis unit 205 analyzes it and outputs it to the output unit 207. The output unit 207 is a monitor that displays video. Here, information such as the title name and recording time related to the content is displayed as a list on the screen.

  A screen display example in the output unit 207 is as shown in FIG. On the screen, information such as the recording date, recording start time, channel number, and title name of the content stored in the server is displayed in a list. In addition, the display screen has a sub-screen for preview reproduction, and the video of the focused content is displayed. From this state, when the user switches the content to be focused by performing a remote control operation or the like, the content displayed on the child screen is switched. When the user starts normal playback of the content by performing a remote control operation or the like, the screen is switched, and full-screen playback of the selected content is started. A screen display example of full screen playback is as shown in FIG. In the output unit 207, the size of the area (window) for displaying the received content may be a plurality of forms including, but not limited to, full screen playback and preview screen playback as shown in FIGS. Have

  Regardless of whether full-screen playback or preview playback on a sub-screen is performed, content playback is performed according to the following procedure. First, prior to content acquisition, management information related to content is acquired. The management information acquisition request (that is, the HTTP GET request) is transmitted via the transmission unit 201, and the management information transmitted from the server is received via the reception unit 202. By analyzing the received management information in the management information analysis unit 204, information related to the internal structure of the content can be known.

  Special reproduction such as fast-forwarding and rewinding can be realized by designating a range of data to be acquired based on information obtained by the management information analysis unit 204. Specifically, for example, fast-forward playback and rewind playback are realized by continuously acquiring and displaying only I pictures of content. Alternatively, the special reproduction speed can be changed by switching the I picture acquisition interval.

  Note that, when it is not necessary to know information regarding the internal structure of content, such as when special playback is not performed, it is not always necessary to acquire management information. Also, if the server does not have content management information or only has management information in a format that cannot be analyzed, it is not necessary to acquire management information.

  Next, actual data of the selected content is acquired from the server. A content acquisition request to the server (that is, an HTTP GET request) is transmitted via the transmission unit 201. The content transmitted from the server is received via the receiving unit 202. The received data is decoded by the decoding unit 206 and then output to the output unit 207. Thereby, the received content can be output as video or audio. These controls are performed in the reproduction control unit 203. Here, the decoding unit 206 is a decoder or the like that decodes data. The output unit 207 may be a storage medium such as an HDD or a DVD for recording content.

  FIG. 6 is used to describe in detail the operation during preview reproduction. FIG. 6 is a flowchart showing the operation procedure of the content receiving apparatus 200 during preview reproduction.

  The content receiving apparatus 200 first establishes a TCP connection with the server (S1). Next, a management information acquisition request is transmitted to the server (S2), and the management information transmitted from the server is received (S3). Next, a content acquisition request is transmitted to the server (S4). The content receiving device 200 receives content transmitted from the server (S5). At this time, the content reception apparatus 200 generally prepares a content reception buffer, and repeatedly executes reception processing in a specific size unit.

  When the reception for a certain size is completed, it is determined whether or not the reception for the size specified from the server is completed (S6). When the reception of all contents is completed, the TCP connection is disconnected (S9), and the reception of contents is terminated. On the other hand, if content transmitted from the server still remains, the process proceeds to S7.

  In S7, it is determined whether the display mode of the currently received content is full screen playback or preview playback. In the case of full-screen playback, the reception process in S5 is repeatedly executed until reception of all contents is completed. On the other hand, if it is not full-screen playback, the connection is automatically disconnected after a certain period of time, and the content reception ends. That is, if No in S7, it is determined whether or not a certain time has elapsed from the start of reproduction (S8), and if time has elapsed, the connection is disconnected and content reception is terminated (S9). If not, the process proceeds to S5 again to continue receiving content.

  In this way, content reception is continued for full-screen playback, and content reception ends when a predetermined time has elapsed for preview playback. As a result, it is possible to prevent unnecessary network bandwidth from being occupied and to effectively use resources throughout the network.

  In some cases, the size of content to be transmitted from the server is not specified. In this case, it can be determined that transmission of all the content has been completed when the connection is disconnected from the server. That is, in the determination in S6, when the connection is disconnected from the server, it may be determined that reception of all contents is completed.

  Connection disconnection during content transmission is not limited to disconnection from the client side, but may be disconnected from the server side. Hereinafter, an operation procedure when disconnecting from the server will be described with reference to FIG.

  Here, as a premise, it is assumed that the content transmitting apparatus 100 acquires in advance information such as whether the content receiving apparatus 200 has received content in full-screen playback or content in preview playback. As a notification method, a method of adding a unique extension header to an HTTP request or response for notification, a method of adding a parameter field uniquely expanded in UPnP action transmission / reception, and the like can be considered. Note that it is assumed that preview playback is switched to full-screen playback during content transmission, and vice versa. In this case, information is notified from the client to the server at the timing of switching. For example, it is assumed that the content transmission apparatus 100 always holds the latest information.

  First, the content transmission apparatus 100 establishes a TCP connection with a client (S11). In this state, it waits for a request from the client.

  When the management information acquisition request is received from the client (Yes in S12), the management information is transmitted (S13), and the state transitions to the standby state again.

  When a content acquisition request is received from the client (Yes in S14), the content is transmitted (S15). At this time, the content transmission apparatus 100 generally prepares a buffer for content transmission, and repeatedly executes transmission processing in a specific size unit.

  When transmission of a certain size is completed, it is determined whether or not transmission of all contents has been completed (S16). When the transmission of all contents is completed, the TCP connection is disconnected (S19), and the content transmission is terminated. On the other hand, if content transmitted from the server still remains, the process proceeds to S17.

  In S17, it is determined whether the playback mode on the client side of the currently transmitted content is full screen playback or preview playback. In the case of full-screen playback, the transmission process in S15 is repeatedly executed until transmission of all contents is completed. On the other hand, if it is not full-screen playback, the connection is automatically disconnected after a certain period of time, and the content reception ends. That is, if No in S17, it is determined whether or not a certain time has elapsed from the start of reproduction (S18), and if time has elapsed, the connection is disconnected and content transmission is terminated (S19). If not, the process proceeds to S15 again and the content transmission is continued.

  In this way, content transmission is continuously performed for full-screen playback, and content transmission is terminated when a predetermined time has elapsed for preview playback. As a result, it is possible to prevent unnecessary network bandwidth from being occupied and to effectively use resources throughout the network.

  In the embodiment of the present invention, it is assumed that there is no particular limitation on the time until the content transmission device 100 or the content reception device 200 disconnects during preview playback. However, if this time is long, the load on the network increases, and if it is too short, there is a problem that the convenience of the user is lowered. Therefore, it is desirable to set the optimum value in consideration of both of these.

  In addition, whether or not viewing on the preview screen is actually necessary may vary depending on factors such as the total number of contents and recording time, so the time until disconnection is adaptive according to these values. It is also possible to change the usage. Specifically, when the total number of contents is small, for example, when there is only one content, the necessity for preview reproduction is low, so that the time until disconnection can be set short. Alternatively, if 10% of the content recording time is set as the preview playback disconnection time, the preview playback time can be changed according to the recording time.

  In the embodiment of the present invention, the factor that the content receiving device 200 determines the end of content reception is not limited to the elapsed time since the start of content reception. Furthermore, it is desirable to be able to detect that the user is not viewing the preview playback screen. For example, content reception may be terminated when a remote control operation from the user has not been performed for a certain period of time. In such a case, it is desirable to display a message that prompts the user to operate the remote control by displaying a message on the screen displaying the preview reproduction before the content reception ends.

  Further, in the embodiment of the present invention, it is desirable that the preview playback screen after the content receiving apparatus 200 finishes receiving the content is displayed in a form that the user does not feel uncomfortable. For example, a message indicating that the preview reproduction has been stopped may be displayed as a message to notify the user. Alternatively, a method of temporarily storing the received content data until the stop, and reproducing and displaying the temporarily stored content from the top again on the preview screen after the stop, and then repeatedly reproducing and displaying the content thereafter Is also possible.

  In the embodiment of the present invention, the operation when stopping the preview reproduction is not limited to the disconnection of the TCP connection. For example, in the case of a content receiving device, an ACK packet with a window size of 0 may be transmitted without receiving content while maintaining a TCP connection. In such a case, content data does not flow on the network, so that an equivalent effect of reducing the load on the network can be obtained.

  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.

Diagram showing an example of preview playback screen Diagram showing an example of full-screen playback Configuration diagram of a network according to an embodiment of the present invention Configuration diagram of content transmission apparatus according to an embodiment of the present invention Configuration diagram of content receiving apparatus according to an embodiment of the present invention The flowchart which shows the operation | movement procedure of the content receiver in embodiment of this invention. The flowchart which shows the operation | movement procedure of the content transmission apparatus in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Communication line 100 Content transmission apparatus 101 Transmission part 102 Reception part 103 Transmission control part 104 Management information generation part 105 Attribute information generation part 106 Content storage part 200 Content reception apparatus 201 Transmission part 202 Reception part 203 Playback control part 204 Management information analysis part 205 Attribute Information Analysis Unit 206 Decoding Unit 207 Output Unit 208 Input Unit

Claims (6)

A receiving unit that receives content from a content transmitting device connected via a network, and an output unit that reproduces and displays the content video having a plurality of display forms having different window sizes for displaying the received video of the content And a playback control unit that instructs the receiving unit to stop receiving the content in a specific display mode among a plurality of display modes displayed by the output unit. apparatus. The playback control unit instructs the receiving unit to stop receiving the content when it detects that a predetermined time has elapsed since the start of receiving the content in the specific display form. The content receiving apparatus according to claim 1, wherein: The reproduction control unit determines whether or not the content displayed by the output unit is being viewed in the specific display form, and stops receiving the content when determining that the content is not being viewed The content receiving apparatus according to claim 1, wherein an instruction is given to the receiving unit. The content reproduction apparatus further includes an input unit that receives an instruction regarding content reproduction, and the reproduction control unit detects whether or not there is an input from the input unit in the specific display form, and an input for a predetermined time is performed. The content receiving apparatus according to claim 3, wherein it is determined that the content is not viewed when it is detected that there is no content. A transmitting unit that transmits content to a content receiving device connected via a network; and the size of the window in which the content receiving device displays the content is acquired, and the size of the window is in a specific display form. In some cases, the content transmission apparatus includes: a transmission control unit that instructs the transmission unit to stop transmission of the content. The transmission control unit instructs the transmission unit to stop the transmission of the content when detecting that a predetermined time has elapsed since the transmission of the content in the specific display form has started. The content transmission apparatus according to claim 5, wherein

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