JP2008167194A - Content transmitting method, content receiving method, content transmitting apparatus, and content receiving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To instruct the reception of a prescribed stream in NVOD. <P>SOLUTION: A content storage part 36 stores contents. A content acquiring part 38 regulates the plurality of contents by deviating the time of the prescribed content and generates the respective contents as the different streams. A content distributing part 40 transmits the generated streams in parallel. A connection setting information distributing part 34 transmits stream information which is related to each stream to be transmitted in the content distributing part 40 and also is related to relative time from a designation position in the content. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a content transmission technology and a content reception technology, and more particularly to a content transmission method, a content reception method, a content transmission device, and a content reception device that transmit content in near video on demand.

Coupled with the progress of information terminal devices such as personal computers and mobile phones, advertising by communication centering on the Internet is becoming common. In particular, the self-broadcasting system uses the wireless LAN technology to perform multicast distribution of content, and can easily use a mobile phone with a high penetration rate as a receiving terminal. Therefore, the independent broadcasting system is expected as a simple communication advertising means in a small / medium scale network. In a self-broadcasting system, when content including video, audio, and metadata is periodically distributed via multicast, it is difficult to start viewing from an arbitrary viewing position such as the top of the content. Therefore, a near video on demand (NVOD) system has been proposed. This defines a plurality of streams while shifting the start time of predetermined content, and distributes the plurality of streams simultaneously. In addition, a predetermined stream is selected by the viewer (see, for example, Patent Documents 1 and 2).
JP 2002-353964 A JP 2004-88315 A

  When an advertisement is inserted into content, the content distributor generally desires to view the advertisement. However, in NVOD, content to be viewed is selected by the viewer, so the content distributor cannot force viewing from the intended position. Therefore, NVOD is not suitable for periodic distribution of contents such as advertisements that have different importance of viewing position.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a content transmission technique and a content reception technique for instructing reception of a predetermined stream in NVOD.

  In order to solve the above problems, a content transmission device according to an aspect of the present invention defines a plurality of contents while shifting the time of predetermined content, and generates a plurality of contents as separate streams, A first transmission unit that transmits a plurality of streams generated in the generation unit in parallel, stream information related to each stream to be transmitted in the first transmission unit, and a relative time from a specified position in the content And a second transmission unit for transmitting stream information related to.

  “Content” corresponds to each of video data, audio data, information data included in a program, or any combination thereof. In addition, the “content” may be video data itself, or may be obtained by performing processing such as encoding on video data or the like. According to this aspect, it is possible to suggest content to be received by separately transmitting stream information in addition to the stream and notifying information related to the relative time from the specified position in the content in the stream information.

  The second transmission unit is configured to identify a stream having a relative time suitable for the connection time based on the connection time of the content reception device to the first transmission unit, and the identified stream as stream information. And means for transmitting information for identifying. In this case, since the information for identifying the specified stream is transmitted as the stream information, it is possible to reliably notify the content to be received.

  The generation unit predefines a time difference between a plurality of contents, and the first transmission unit transmits a stream having a relative time suitable for the connection time when the content reception device is connected. Otherwise, transmission of the stream may be started, and the second transmission unit may generate stream information by reflecting the stream for which transmission is started in the first transmission unit. In this case, if a stream having a relative time suitable for the connection time is not transmitted when the content receiving apparatus is connected, transmission of the stream is started, so that the content can be efficiently distributed.

  The first transmission unit may detect that the content receiving device is not connected and stop transmission of the stream. In this case, when the content receiving apparatus is not connected, the transmission of the content is stopped, so that the content can be distributed efficiently.

  Another aspect of the present invention is a content receiving apparatus. This device defines a plurality of contents while shifting the time of predetermined contents, and is a plurality of streams formed by each of the plurality of contents, and any one of the plurality of streams transmitted in parallel is selected. The first receiving unit to be reproduced and the stream information related to each stream that is a candidate for reproduction in the first receiving unit, and the stream information related to the relative time from the specified position in the content is received. A second receiving unit that selects the stream based on the stream information received by the second receiving unit, and instructs the first receiving unit to receive the selected stream.

  According to this aspect, the stream information transmitted separately in addition to the stream is received, and the stream information includes information related to the relative time from the specified position in the content. By selecting a stream, it is possible to receive a stream that the distributor wants to receive in NVOD.

  Yet another aspect of the present invention is a content transmission method. This method is a content transmission method for defining a plurality of contents while shifting the time of predetermined contents, generating each of the plurality of contents as separate streams, and transmitting the plurality of streams in parallel. Stream information related to each stream to be transmitted and stream information related to a relative time from a specified position in the content is transmitted.

  Yet another aspect of the present invention is a content receiving method. In this method, a plurality of contents are defined while shifting the time of predetermined contents, and each of the plurality of streams formed by each of the plurality of contents and transmitted in parallel is selected. A content reception method to be played back, which is stream information related to each stream that is a candidate for reception, and receives stream information related to a relative time from a specified position in the content. Select a stream based on it.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, it is possible to instruct reception of a predetermined stream in NVOD.

  Before describing the present invention in detail, an outline will be described. An embodiment of the present invention relates to a content distribution system in which a server device distributes a plurality of streams by NVOD and a terminal device reproduces content included in the stream after receiving the stream. In such a configuration, the server device executes the following process to cause the terminal device to receive any one of the plurality of streams. Here, any one of the plurality of streams is a specific stream intended by the content distributor. The server device distributes a plurality of streams and distributes stream information regarding a stream to be received among the plurality of streams. When the terminal device receives the stream information, the terminal device identifies the stream based on the stream information, and reproduces it after receiving the identified stream. Therefore, the intention of the content distributor is reflected in the content played back on the terminal device.

  FIG. 1 shows a configuration of a content distribution system 100 according to an embodiment of the present invention. The content distribution system 100 includes a server device 10 and a terminal device 12. The server device 10 includes an information distribution antenna 14 and a stream distribution antenna 16, and the terminal device 12 includes an information reception antenna 18 and a stream reception antenna 20.

  The server device 10 accumulates content. Here, the server device 10 defines a plurality of contents while shifting the reproduction start time of the same contents by a certain time. The server device 10 periodically distributes a plurality of contents as a plurality of streams, particularly a plurality of multicast streams, from the stream distribution antenna 16. That is, the server device 10 executes NVOD. Multicast distribution from the stream distribution antenna 16 is performed by a wireless LAN system, for example, a system compliant with the IEEE802.11b standard. The server device 10 executes conversion of the stored content into a communication content format, and the communication content corresponds to the above-described stream.

  The “communication content” is a format particularly suitable for transmission by a wireless LAN method or the like. In the following description, a stream and communication content are used without distinction. In addition to the above processing, the server device 10 distributes stream information, connection setting information, and the like from the information distribution antenna 14. Details of the stream information and the connection setting information will be described later, and these correspond to a control signal for receiving multicast distribution from the stream distribution antenna 16. Distribution from the information distribution antenna 14 is performed by a short-range wireless communication system, for example, a system compliant with the IEEE 802.15.1 standard or the IEEE 802.15.4 standard.

  The terminal device 12 receives stream information, connection setting information, and the like from the server device 10 at the information receiving antenna 18. The terminal device 12 performs settings for receiving a stream based on the received stream information, connection setting information, and the like. The stream is received by the stream receiving antenna 20 using the wireless LAN method. The terminal device 12 converts the received stream, that is, the format of the communication content into a broadcast format. Further, the terminal device 12 outputs the content converted into the broadcast format. Note that the content distribution system 100 may include a plurality of server devices 10 and terminal devices 12.

  FIG. 2 shows the configuration of the server device 10. The server device 10 includes a connection setting information storage unit 30, a connection setting information addition unit 32, a connection setting information distribution unit 34, a content storage unit 36, a content acquisition unit 38, a content distribution unit 40, a stream information acquisition unit 42, and stream information addition. Unit 44, control unit 46, information distribution antenna 14, and stream distribution antenna 16.

  The content storage unit 36 stores content to be distributed. Also, it is assumed that an advertisement is inserted into the content. Note that the content storage unit 36 may be provided outside the server device 10. The content acquisition unit 38 selects specific content from the content stored in the content storage unit 36. The content acquisition unit 38 generates a plurality of contents while shifting the time of the selected contents. The content acquisition unit 38 predefines a time difference between a plurality of contents. The content acquisition unit 38 outputs each of the generated plurality of contents to the content distribution unit 40 as a separate stream.

  In the above processing, the content acquisition unit 38 converts the content format into a format suitable for streaming delivery (hereinafter, a content in a format suitable for streaming delivery is also referred to as “communication content” or “stream”). That is, the content acquisition unit 38 acquires content stored in the content storage unit 36, converts the content format into a format that can be distributed by the wireless LAN method, and outputs the converted communication content to the content distribution unit 40. The content distribution unit 40 multicasts the plurality of streams generated by the content acquisition unit 38 from the stream distribution antenna 16 in parallel. Parallel distribution is realized by, for example, different multicast addresses. That is, the content distribution unit 40 executes NVOD. As described above, the content distribution unit 40 corresponds to the wireless LAN system. Therefore, the communication content is formed by a plurality of IP packets and becomes a stream.

  FIG. 3 shows a format of a stream distributed from the server device 10. Here, the number of streams is “3”. The number of streams may be set to an arbitrary number of 1 or more within the range of physical restrictions of communication. In each stream “ST001”, “ST002”, and “ST003”, the bold line portion is a part of the data being periodically distributed, and corresponds to the minimum area including the beginning to the end of the content. That is, each stream is formed by a data string in which the content indicated by the bold line portion is continuous. Here, the time difference between the contents included in each stream is defined so that the total reproduction time of the original same content is equally distributed by the number of multicast streams. A period obtained by dividing one content into three equal parts is shown in FIG. 3 as “W200”, “W201”, “W202”, and “W203”.

  In FIG. 3, it is assumed that the content distributor expects the content to be reproduced from the time position “P201”. For example, an advertisement is inserted at the position “P201”. When the terminal device 12 (not shown) is connected to the server device 10 within the period “W200”, the stream that includes the “P201” position and is in the nearest position is “ST002”. Therefore, it is preferable for the content distributor to have the terminal device 12 receive “ST002”. Therefore, as described later, the server apparatus 10 notifies the stream information including information indicating “ST002”. Similarly, when connection is made within the period “W201”, information indicating “ST003” is included in the stream information, and when connection is made within the period “W202”, information indicating “ST001” is included in the stream information. included. The designated position “P201” of the content is set to an arbitrary position including the top of the content.

  4A to 4D show the format of content processed in the server device 10. FIG. 4A shows a content format defined in terrestrial digital broadcasting. FIG. 4A corresponds to the aforementioned broadcast format. The content is composed of a plurality of TS packets, which are shown as “TS1”, “TS2” to “TS18” in FIG. 4A. A TS packet is a unit of data defined in digital terrestrial broadcasting. A terminal device 12 (not shown) can use a decoding function for digital terrestrial broadcasting on a TS packet.

  Each format shown in FIGS. 4B to 4D corresponds to each of the parts obtained by dividing one content into three parts in FIG.

  Further, the content acquisition unit 38 adds the unique header shown in FIGS. 4B to 4D to the content acquired from the content storage unit 36. Here, information regarding the divided contents is included in the unique header. Here, the content acquisition unit 38 dynamically adds a unique header to each content, but the content storage unit 36 may store content with the unique header added.

  5A to 5E show the format of the IP packet generated in the server device 10. FIG. 5A shows the format of an IP packet. The IP packet is composed of an IP header portion and an IP packet data portion. A series of IP packets corresponds to a stream. FIG. 5B shows the format of the IP packet data part, and the IP packet data part is composed of a UDP header part and a UDP data part. FIG. 5C shows the format of the UDP data part, which is composed of an RTP header part and an RTP data part.

  FIG. 5D shows the format of the RTP data portion, and the RTP data portion is composed of a unique header portion and a unique data portion. FIG. 5E shows the configuration of the unique data portion, and the content to be distributed is stored in the format of a plurality of TS packets in the unique data portion. One IP packet may store one TS packet, or may store a plurality of TS packets as illustrated. When all the TS packets of content cannot be stored in one IP packet, as shown in FIGS. 4B to 4D, the TS packet is divided according to the order of the data string, and each of them is unique to a plurality of IP packets. You may store in a data part.

  When the content acquisition unit 38 receives the content shown in the format of FIG. 5E from the content storage unit 36, FIG. 5D, FIG. 5C, FIG. 5B, FIG. Conversion is performed in the order of (a). Returning to FIG.

  The stream information acquisition unit 42 acquires stream information of the content selected by the content acquisition unit 38. That is, the stream information acquisition unit 42 acquires stream information related to each stream to be transmitted by the content distribution unit 40 and related to relative time from a specified position in the content. Here, the relative time from the specified position in the content corresponds to the time to “P201” in “ST002” when “P201” in “ST001” in FIG. 3 is used as a reference. Such stream information is stored in the content storage unit 36.

  In particular, the stream information acquisition unit 42 specifies a stream having a relative time suitable for the connection time based on the connection time of the terminal device 12 (not shown) to the content distribution unit 40. This corresponds to the identification of the stream “ST002” when the server apparatus 10 is connected in the period “W200” as described in FIG. Further, the stream information acquisition unit 42 selects information for identifying the identified stream, for example, information for identifying “ST002” as the stream information.

  As described above, the stream information acquired by the stream information acquisition unit 42 includes only information for specifying one stream, so that only one stream exists for the terminal device 12 that has received the information. It becomes possible to inform. Here, the information for specifying one stream corresponds to information related to the relative time from the specified position in the content. In this case, the relative time from the specified position in the content for each stream is not shown directly, but the stream identification result is shown based on the relative time of each stream. The stream information adding unit 44 outputs the stream information acquired by the stream information acquiring unit 42 to the connection setting information distributing unit 34.

  The connection setting information storage unit 30 stores connection setting information regarding the server device 10. Here, the connection setting information is information to be set in the terminal device 12 (not shown) in order to connect to the server device 10. For example, the server device 10 corresponds to an ESS-ID or the like when the content distribution unit 40 is compatible with a wireless LAN system. The connection setting information adding unit 32 acquires the connection setting information stored in the connection setting information storage unit 30 and outputs the acquired connection setting information to the connection setting information distribution unit 34. The connection setting information distribution unit 34 distributes stream information and connection setting information from the information distribution antenna 14. The connection setting information distribution unit 34 corresponds to the short-range wireless communication method. The connection setting information distribution unit 34 may exist outside the server device 10. The control unit 46 controls the operation of the components included in the server device 10.

  FIGS. 6A and 6B show the format of connection setting information and stream information distributed from the server device 10. FIG. 6A shows basic setting information at the time of connection in the wireless LAN system. As shown, an ESSID field 200, a WPA key information field 202, and an IP address field 204 are included. FIG. 6B shows stream information. As shown, a stream ID column 206, a stream name column 208, an IP address column 210, a port number column 212, and a channel number column 214 are included. Here, a case where “ST002” is specified is shown.

The channel number column 214 is a virtual channel simulating the concept of a channel in a television receiver. In this example, a stream “ST002” is assigned to the channel CH1.
In FIG. 6 (b), stream information regarding one stream to be received is shown, but such stream information is a selection result of one of a plurality of streams. Yes. Also, since one stream has an optimal timing, it is related to a relative timing from a designated position in the content.

  FIG. 6B illustrates only one channel number. However, when there are a plurality of stream groups to be distributed in the configuration of FIG. 3, that is, when a plurality of types of contents are distributed, The same channel number as in FIG. 6B may be assigned. When the terminal device 12 (not shown) selects a stream, that is, a multicast address based on the stream information and performs reproduction, the stream information does not include information on a stream other than the stream that the content distributor desires to reproduce. That is, reproduction of a stream unintended by the content distributor by the terminal user is prevented. Returning to FIG.

  The content distribution unit 40 distributes a plurality of streams to one content as shown in FIG. Such a state corresponds to a steady state. On the other hand, the state of the content distribution unit 40 includes an initial state and an end state in addition to a steady state. The initial state corresponds to a state in which the number of connected terminal devices 12 gradually increases from a state in which the terminal device 12 is not connected to the server device 10. Among these, in a state where the terminal device 12 is not connected to the server device 10, the content distribution unit 40 does not distribute the stream. Further, the content distribution unit 40 increases the number of streams to be distributed as the number of terminal devices 12 increases.

  Specifically, when the terminal device 12 is connected, the content distribution unit 40 starts transmission of the stream if it has not transmitted a stream having a relative time suitable for the connection time. Here, the stream having a relative time suitable for the connection time is a stream including a timing that the content distributor wants to view, and a stream when connected in the period “W200” in FIG. This corresponds to “ST002”. Here, it is assumed that the content distribution unit 40 cannot transmit a stream at an arbitrary timing. That is, the relative relationship from “ST001” to “ST003” is defined in advance, and the content distribution unit 40 transmits a stream at those timings.

  In addition, the stream information acquisition unit 42 reflects the stream from which transmission is started in the content distribution unit 40 to generate stream information. On the other hand, the terminal state corresponds to a state in which the terminal device 12 is connected to the server device 10 but is not connected thereafter. When the content distribution unit 40 detects that the connected terminal device 12 no longer exists, the content distribution unit 40 stops the transmission of the stream.

  FIG. 7 shows an initial stream format distributed from the server device 10. In a state where no terminal device 12 is connected to the server device 10, the server device 10 does not perform multicast distribution at all. When the first terminal device 12 illustrated as “MT1” is connected at timing “T501”, the server device 10 multicasts from the designated position “P501” of the content as a stream “ST001” using the connection as a trigger. Start distribution.

  Further, when the second terminal apparatus 12 illustrated as “MT2” is connected at timing “T502”, the server apparatus 10 specifies the nearest stream “ST002” including the designated position. Here, if “ST002” has not been transmitted, the server apparatus 10 newly starts transmission of the stream “ST002”. However, at this time, the transmission start time position in the content is assumed to be from the position defined as the original distribution schedule frame. For this reason, transmission is performed from a position returned by “D501” from the position “P501”. The same procedure is applied to subsequent connections. This approach maintains compatibility with the steady state of FIG.

  Further, the server device 10 stops transmission of a stream that has not been received, triggered by the disconnection of the terminal device 12 connected to the server device 10. Therefore, when there is no terminal device 12 participating in the network, the server device 10 transitions to the untransmitted state, which is the initial state of FIG. In general, the detachment of the terminal device 12 from the network can be detected in the physical layer, and this can be used only to confirm that no terminal device 12 exists. The departure from a specific multicast address is determined by the presence or absence of an exit message in the IGMP protocol or an IGMP response message for a periodic inquiry from the router.

  This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of any computer, and in terms of software, it is realized by a program having a communication function loaded in the memory. Describes functional blocks realized by collaboration. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  FIG. 8 shows the configuration of the terminal device 12. The terminal device 12 includes a connection setting information reception unit 60, a stream information acquisition unit 62, a connection setting processing unit 64, a stream determination unit 66, a LAN communication unit 68, a stream processing unit 70, an audio output unit 72, a display unit 74, and a control unit. 76, an information receiving antenna 18 and a stream receiving antenna 20.

  The connection setting information receiving unit 60 corresponds to the short-range wireless communication method. Further, the connection setting information receiving unit 60 receives the connection setting information and the stream information distributed from the connection setting information distributing unit 34 (not shown) via the information receiving antenna 18. The connection setting information receiving unit 60 outputs the received connection setting information to the connection setting processing unit 64, and outputs the received stream information to the stream information acquiring unit 62. Based on the received connection setting information, the connection setting processing unit 64 causes the LAN communication unit 68 to execute a wireless LAN connection with the content distribution unit 40 (not shown). At this time, connection setting information is used as a parameter for wireless LAN connection.

  The stream information acquisition unit 62 outputs the received stream information to the stream determination unit 66 after connection by the LAN communication unit 68. That is, the stream information acquisition unit 62 acquires stream information related to each stream that is a stream reception target candidate and related to relative time from a specified position in the content. The stream determination unit 66 instructs the stream processing unit 70 to receive a stream according to the stream information. That is, the stream determination unit 66 selects a stream based on the stream information received by the stream information acquisition unit 62 and instructs the stream processing unit 70 to receive the selected stream.

  The LAN communication unit 68 corresponds to a wireless LAN system. The LAN communication unit 68 receives a stream from a content distribution unit 40 (not shown) via the stream receiving antenna 20. As described above, the LAN communication unit 68 executes connection processing for connecting to the content distribution unit 40 in response to an instruction from the connection setting processing unit 64. The LAN communication unit 68 outputs the received stream to the stream processing unit 70.

  The stream processing unit 70 receives a stream from the LAN communication unit 68 and processes the received stream in accordance with an instruction from the stream determination unit 66. That is, the stream processing unit 70 processes one of a plurality of streams transmitted in parallel. Here, since the received stream has the IP packet format, the stream processing unit 70 extracts the IP packet data part from the IP packet, and then extracts the TS packet from the IP packet data part. As described above, the UDP packet is stored in the IP packet data part, and further, the RTP packet is stored in the UDP packet data part of the UDP packet. Since such an RTP packet includes a TS packet, the stream processing unit 70 extracts the TS packet from the RTP packet.

  The stream processing unit 70 sequentially analyzes the TS packets and reproduces the content. At this time, the stream processing unit 70 sorts video and audio TS packets based on PID (Packet ID). In addition, the stream processing unit 70 is provided with a built-in AAC decoder or H.264 according to the selection result. The TS packet is processed by the H.264 decoder. For this process, a packet including control information called SI / PSI (Service Information / Program Specific Information) is used. In addition to the video signal and the audio signal, data broadcast and caption information may be included, but they are omitted in this embodiment.

  H. The H.264 decoder removes the header of the TS packet related to the video and concatenates the payload to generate a PES (Packetized Elementary Stream) packet. H. The H.264 decoder obtains an ES (Elementary Stream) by removing the header of the PES packet and concatenating the payload. Further, H.C. The H.264 decoder decodes the ES and outputs an uncompressed video signal to the display unit 74. The AAC decoder performs H.264 for voice packets. It operates in the same manner as the H.264 decoder and outputs an audio signal to the audio output unit 72.

  The display unit 74 is configured by a liquid crystal screen or the like. A video is provided to the user by displaying the video signal output from the H.264 decoder. The audio output unit 72 also includes a speaker and the like, and provides audio to the user by outputting the audio signal output from the AAC decoder. The control unit 76 controls the operation of the components included in the terminal device 12.

  The operation of the content distribution system 100 configured as above will be described. FIG. 9 is a flowchart showing a stream distribution procedure by the server apparatus 10. If the terminal device 12 is not connected (N in S10), the content distribution unit 40 stands by. When the terminal device 12 is connected (Y in S10), the content distribution unit 40 starts content distribution from the top (S12), and the control unit 46 sets the time schedule of the stream with a preset time shift. to manage. Thereafter, if there is a new terminal device 12 connection (Y in S14), the control unit 46 specifies a stream suitable for the new terminal device 12 based on the connection timing (S16).

  If the specified stream is not actually distributed (N in S18), the content distribution unit 40 starts distributing the specified stream (S20), and then the connection setting information distribution unit 34 distributes the stream information ( S22). On the other hand, if the identified stream is actually distributed (Y in S18), step 20 is skipped. If there is no new terminal device 12 connected (N in S14), the processing from step 16 to step 22 is skipped. If there is a connected terminal device 12 (Y in S24), the process returns to step 14. On the other hand, if there is no terminal device 12 connected (N in S24), the control unit 46 determines whether or not to end the distribution (S26). When the distribution is finished (Y in S26), the process is finished. If the distribution is not terminated (N in S26), the process returns to step 10.

FIG. 10 is a flowchart showing a stream reception procedure by the terminal device 12.
The LAN communication unit 68 detects entry into the LAN connectable area (S50). If the connection setting information receiving unit 60 does not receive the connection setting information and the stream information (N in S52), the connection setting information receiving unit 60 stands by. When the connection setting information receiving unit 60 receives the connection setting information and the stream information (Y in S52), the connection setting processing unit 64 causes the LAN communication unit 68 to make a LAN connection based on the connection setting information (S54). Further, the stream processing unit 70 receives the stream specified by the stream information from the stream determining unit 66 (S56). If the stream is not finished (N in S58), the process returns to step 56. On the other hand, if the stream ends (Y in S58), the process ends.

  Hereinafter, modifications according to the present invention will be described. In the embodiment, the server device 10 generates stream information so as to specify one stream per one content. Therefore, an association between a stream ID and a channel number is provided as stream information. On the other hand, in the modified example, information on all streams is included in the stream information.

  FIG. 11 is a diagram showing a format of stream information distributed from the server device 10 according to the modification of the present invention. As shown, a stream ID column 206, a stream name column 208, an IP address column 210, a port number column 212, and a relative time information column 216 are included. In this way, the stream information about all streams is notified to the terminal device 12 so as to include the relative time information between the position desired by the content distributor and the terminal connection completion time. In this case, the terminal device 12 selects a stream with the smallest relative time information.

  According to the embodiment of the present invention, content to be received is transmitted by separately transmitting stream information in addition to the stream and notifying information related to the relative time from the specified position in the content in the stream information. Can be suggested. Moreover, since the content to be received is suggested, it is possible to instruct reception of the predetermined content in NVOD. Further, since the information for identifying the specified stream is transmitted as the stream information, it is possible to reliably notify the content desired to be received. If a stream having a relative time suitable for the connection time is not transmitted when the terminal device is connected, transmission of the stream is started, so that the content can be efficiently distributed. In addition, even when transmission of a new stream is started, since transmission from a predetermined timing is started, the processing can be simplified.

  Also, if the terminal device is not connected, the stream is not distributed, so that power consumption can be reduced. Further, when there is no connected terminal device, the content transmission is stopped, so that the content can be distributed efficiently. Also, stream information transmitted separately in addition to the stream is received, and the stream information includes information related to the relative time from the specified position in the content. By selecting, it is possible to receive content that the distributor wants to receive in NVOD. In addition, since stream information including information on all streams is received, a desired stream can be selected.

  In addition, in a self-broadcasting system network using multicast distribution, a specific viewing position intended by the content distributor can be forced on the user of the terminal device. Further, by manipulating the transmission start timing of multicast distribution, it is possible to shorten the reproduction start time of the designated position under specific conditions, improve network traffic, and save power.

  In the above, this invention was demonstrated based on the Example. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

  In the embodiment of the present invention, the connection setting information distribution unit 34 and the connection setting information receiving unit 60 are compatible with the short-range wireless communication system. However, the present invention is not limited to this. For example, the connection setting information distribution unit 34 and the connection setting information receiving unit 60 may support a wireless LAN system. According to this modification, the present invention can be applied even when only one wireless communication system is supported.

It is a figure which shows the structure of the content delivery system which concerns on the Example of this invention. It is a figure which shows the structure of the server apparatus of FIG. It is a figure which shows the format of the stream delivered from the server apparatus of FIG. FIGS. 4A to 4D are diagrams showing a format of content processed in the server apparatus of FIG. FIGS. 5A to 5E are diagrams showing formats of IP packets generated in the server apparatus of FIG. FIGS. 6A and 6B are diagrams showing the format of connection setting information and stream information distributed from the server apparatus of FIG. It is a figure which shows the format of the initial stream delivered from the server apparatus of FIG. It is a figure which shows the structure of the terminal device of FIG. It is a flowchart which shows the delivery procedure of the stream by the server apparatus of FIG. It is a flowchart which shows the reception procedure of the stream by the terminal device of FIG. It is a figure which shows the format of the stream information delivered from the server apparatus which concerns on the modification of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Server apparatus, 12 Terminal apparatus, 14 Information delivery antenna, 16 Stream delivery antenna, 18 Information reception antenna, 20 Stream reception antenna, 30 Connection setting information storage part, 32 Connection setting information addition part, 34 Connection setting information Distribution unit, 36 content storage unit, 38 content acquisition unit, 40 content distribution unit, 42 stream information acquisition unit, 44 stream information addition unit, 46 control unit, 60 connection setting information reception unit, 62 stream information acquisition unit, 64 connection setting Processing unit, 66 stream determination unit, 68 LAN communication unit, 70 stream processing unit, 72 audio output unit, 74 display unit, 76 control unit, 100 content distribution system.

Claims (7)

A generation unit that defines a plurality of contents while shifting a predetermined content time, and generates each of the plurality of contents as separate streams;
A first transmitter that transmits a plurality of streams generated in the generator in parallel;
A second transmitter for transmitting stream information related to each stream to be transmitted in the first transmitter;
A content transmission apparatus comprising:   The second transmission unit specifies, as stream information, means for identifying a stream having a relative time suitable for the connection time based on the connection time of the content reception device to the first transmission unit. The content transmitting apparatus according to claim 1, further comprising: means for transmitting information for identifying the stream. The generation unit predefines a time difference between a plurality of contents,
If the first transmission unit does not transmit a stream having a relative time suitable for the connection time when the content receiving device is connected, the first transmission unit starts transmission of the stream,
The content transmission apparatus according to claim 1, wherein the second transmission unit generates stream information by reflecting a stream from which transmission is started in the first transmission unit.   The content transmission device according to claim 3, wherein the first transmission unit detects that the content reception device is not connected and stops transmission of the stream. A plurality of contents are defined while shifting the time of predetermined contents, and a plurality of streams formed by each of the plurality of contents, and one of the plurality of streams transmitted in parallel is reproduced. A receiver,
A second receiver that receives stream information related to each stream that is a candidate for playback in the first receiver;
A control unit that selects a stream based on the stream information received by the second reception unit, and instructs the first reception unit to reproduce the selected stream;
A content receiving apparatus comprising: A content transmission method for defining a plurality of contents while shifting a predetermined content time, generating each of the plurality of contents as separate streams, and transmitting the plurality of streams in parallel.
A content transmission method characterized by transmitting stream information related to each stream to be transmitted. Content reception in which a plurality of contents are defined by shifting the time of predetermined contents, and each of the plurality of streams formed by each of the plurality of contents is played back in parallel. A method,
A content receiving method, comprising: receiving stream information related to each stream that is a candidate for reception, and selecting a stream based on the stream information.

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