JP2008311967A - Content receiver, content reproducing unit, content receiving/reproducing unit, content reception method, content reproduction method, content reception/reproduction method, content reproduction system, program, and computer-readable recording medium recording the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the time required for reproducing content after receiving a video stream. <P>SOLUTION: A content receiver 105a comprises: a program identification information acquisition section 13 for acquiring program identification information for identifying each content from the received stream; a PID information acquisition section 14 for acquiring a PID for identifying a packet for transmitting video or sound included in the stream from the acquired program identification information; and a PID information transmission section 17 for transmitting the acquired PID to a content reproducing unit 103a. Hence, the content reproducing unit for receiving a PID from the content receiver 105a can decode the stream using the received PID, thus reducing the time required for reproducing the content after receiving the stream. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a content receiving apparatus for receiving a stream in which a plurality of video and audio included in a plurality of contents are divided into a plurality of packets and the packets are multiplexed and transmitted, and the contents included in the received streams are The present invention relates to a content reproduction device, a content reception / reproduction device, a content reception method, a content reproduction method, a content reception / reproduction method, a content reproduction system, a program, and a computer-readable recording medium on which the program is recorded.

  With recent advances in communication speed using xDSL (Digital Subscriber Line) and optical fiber technology and advances in compression coding technology, video and audio are distributed using an IP (Internet Protocol) network such as the Internet. Services are being actively provided. In many cases, video and audio distribution destinations in such video distribution services are PCs (Personal Computers). However, in recent years, with the digitalization and networking of AV devices such as televisions, services targeting AV devices other than PCs have started as video and audio distribution destinations.

  In the video distribution service using the Internet as described above, video and audio are distributed as digital data, similarly to satellite / terrestrial digital broadcasting. In satellite / terrestrial digital broadcasting, MPEG2 (Moving Picture Experts Group 2) is adopted as a compression encoding method, and MPEG2-TS (MPEG2-Transport Stream) is adopted as a video and audio stream transmission method. Even in a video distribution service using, MPEG2-TS is generally used as a transmission data format.

(MPEG2-TS)
Hereinafter, a transmission method using MPEG2-TS will be described. In the transmission method using MPEG2-TS, it is possible to multiplex and transmit a plurality of video, audio, character data, etc. in one transport stream. For example, a case where two different contents are transmitted as one video stream will be described as an example. Each content includes two sounds of Japanese and English in addition to the video. In this case, two videos and four audios are multiplexed and included in one transport stream for transmission.

  Next, transport packets (hereinafter referred to as TS packets) constituting a transport stream will be described with reference to FIG. FIG. 22 is a diagram schematically showing the data structure of a TS packet. As shown in FIG. 22, the TS packet is a fixed length packet of 188 bytes, a header portion having a fixed length of 4 bytes, an adaptation portion having a variable length between 0 bytes and 184 bytes, and between 0 bytes and 184 bytes. It consists of a variable-length payload part.

  In the packet part, a packet identifier (PID (Packet Identifier)) which is identification information of the TS packet and various flags are set. The same PID is set in the header for TS packets that transmit the same video or the same audio. Therefore, the type of TS packet can be identified by referring to this PID. Note that different PIDs are assigned not only to video data and audio data but also to TS packets of character information and control information.

  Next, the manner in which video data and audio data to be transmitted are multiplexed into a transport stream will be described with reference to FIGS. FIGS. 23A to 23D are diagrams schematically illustrating how video data and audio data to be transmitted are multiplexed into a transport stream.

  When the video data 501 and the audio data 502 shown in FIG. 23A are multiplexed in the transport stream, first, as shown in FIG. 23B, each is divided into TS packets. That is, it is divided into 184 bytes or less (m1 to m12 and a1 to a4) so that it can be stored in the payload portion of the TS packet. Next, as shown in FIG. 23 (c), a header part and adaptation parts 511 to 526 are added to the divided data. At this time, a PID for identifying the video data 501 and the audio data 502 is assigned to each header portion. Finally, as shown in FIG. 23 (d), each TS packet is collected and transmitted as one transport stream.

  Next, a description will be given of a method in which the receiving apparatus that receives the above-described transport stream extracts video data and audio data from the transport stream.

  When receiving the transport stream, the receiving device first detects a TS packet having a PID value of “0”. Here, a TS packet having a PID value of “0” is referred to as program management information (hereinafter referred to as PAT (Program Association Table)).

  In the PAT, a list of PIDs of TS packets storing information for managing video and audio constituting a program called a program correspondence table (hereinafter referred to as PMT (Program Mapped Table)) is set. . That is, the PAT manages what kind of content is included in the stream.

  The PMT is a TS packet for describing PIDs such as video, audio, and character data included in the corresponding content, and is assigned for each content.

  For example, it is assumed that two different contents are transmitted as one transport stream, and each content includes two sounds, that is, sound in Japanese and sound in English in addition to video. In this case, the PMT includes the PID of a TS packet that stores one video and two audios included in the video content. The PAT stores PIDs corresponding to two PMTs. The PMT may include a PID of a TS packet that stores an ECM (Entitlement Control Message) necessary for decrypting encrypted data.

  If the PID of a TS packet storing video, audio, etc. can be obtained based on the PMT, the original content can be reproduced by collecting the TS packets to which the obtained PID is added. That is, by referring to the PAT and PMT, TS packets constituting desired content can be extracted from the transport stream.

  That is, in order to reproduce specific content, the receiving device first extracts a PAT having a PID value of “0”. Next, the PID of the PMT stored in the PAT is extracted. Next, the PID of the TS packet storing video and audio is extracted from the PMT having the PID. Then, video and audio are decoded based on the PID.

  If the content is encrypted, the PID of the ECM is further extracted from the PMT, and information necessary for decryption is acquired. Then, a decryption key is generated, and video and audio decryption processing is performed.

  In consideration of the fact that the content transmitted by the transport stream may be reproduced from the middle by the receiving device, TS packets such as PAT, PMT, ECM, etc. are periodically sent out. At this time, if the period is shortened, a larger transmission band is used for transmitting the PAT and PMT. Therefore, network traffic increases, which may affect the real-time property transmission. Therefore, normally, the period is set between 100 milliseconds and 1 second.

  Here, even if the period is 100 milliseconds, it takes 100 milliseconds at maximum for detection of PAT and PMT, and 200 milliseconds at maximum in total. That is, in this case, it takes 200 milliseconds as a response time from when the user performs an operation for reproducing the content to the receiving device until the receiving device reproduces the content.

  Further, if the period is 1 second, it takes 1 second at maximum for detection of PAT and PMT, and 2 seconds at maximum in total. That is, in this case, it takes 2 seconds as a response time from when the user performs an operation for reproducing the content to the receiving device until the receiving device reproduces the content.

  As described above, in particular, when selecting a content to be viewed while switching between a plurality of contents, if the time between the switching and the reproduction of the contents is long, user convenience is impaired.

  In order to solve the above problem, information relating to the PID is preliminarily used in the message exchange by the RTSP (Real Time Streaming Protocol) method for requesting transmission of TS packets when the transport stream is distributed by RTP (Real time Transport Protocol). A method is disclosed that does not require detection of PAT or PMT by receiving (see Patent Document 1). In this method, it is disclosed that the content server side includes PID information of a TS packet storing video and audio in a response to a video transmission request.

  According to the above disclosed method, at the time when the requested MPEG2-TS stream is received from the content server, the receiving device does not detect the PAT or PMT, and the PID of the TS packet storing video and audio is detected. Can be acquired. That is, the content is extracted without performing processing such as extracting a PAT, extracting a PID of a PMT stored in the PAT, or extracting a PID of a TS packet storing video and audio from the PMT having the PID. The reproduction process can be started.

(IP multicast technology)
As a method for distributing content via a network, there is a method using an IP multicast technique in addition to a unicast distribution method using RTSP or HTTP (Hyper Text Transfer Protocol). In the IP multicast technology, it is possible to simultaneously distribute to a plurality of transmission destinations by using a multicast address prepared in advance for simultaneous distribution to a plurality of terminals.

  Note that distribution using IP multicast has advantages over unicast distribution such as RTSP in that the load on the network when distributing to a plurality of terminals at the same time is small, and is therefore used in content distribution. There is. That is, in unicast distribution using RTSP or the like, for example, in order to distribute to a plurality of terminals at the same time, a transmission band corresponding to the content transmission rate multiplied by the number of terminals is required. On the other hand, in the distribution using IP multicast, since one video stream is shared by a plurality of terminals and received, only one transmission band is required. However, because there is a demerit that it is difficult to achieve fast-forwarding of video with the receiving device, it is determined by the application which distribution technology to use, unicast distribution or IP multicast distribution. Is common.

  When using the IP multicast technique, the IP multicast transmission side sets the multicast address in the transmission packet as the destination IP address. As the multicast address, “224.0.0.1” to “239.255.255.255” are used in the case of IPv4 (Internet Protocol Version 4). In the case of IPv6 (Internet Protocol Version 6), an address in which the upper 8 bits of the address are all 1, for example, an address such as “FF00 :: 1” is used.

  Then, a network relay device (for example, a router) that receives the IP multicast packet transmitted from the content server determines whether to transfer the IP multicast packet to another network from each connected network. This is determined by whether or not a “JOIN request” of (Internet Group Management Protocol) has been received.

  Here, the IGMP JOIN request is a request for requesting the network relay device to transfer an IP multicast packet. In the IGMP JOIN request, a multicast address requesting transfer is specified. Then, the network relay device transfers only the IP packet whose destination is the designated multicast address to the network that issued the IGMP JOIN request.

  Further, a request for stopping the transfer of the IP multicast packet to the network relay device is made using an IGMP “LEAVE request”. The network relay device that has received the LEAVE request stops forwarding a packet whose destination is the designated multicast address.

  When the network relay device has received a plurality of JOIN requests from the same network, when a LEAVE request corresponding to the received JOIN request is received or when the TIME-out of all JOIN requests has elapsed Then, the transfer of the IP multicast packet is stopped.

  Next, with reference to FIG. 24, description will be given of a procedure for distributing content from the content transmission device to the reception device via the network relay device by the IP multicast technology, and a procedure for displaying the content by the reception device, and a procedure for switching the content. To do. FIG. 24 is a flowchart illustrating a procedure for distributing content from the content transmission device to the reception device via the network relay device by the IP multicast technology, and displaying the content by the reception device, and a flow of processing for switching the content.

  In FIG. 24, the content reproduction device and the network relay device exchange data, and the network relay device and the content transmission device exchange data.

  A certain content is multicast distributed from the content transmission device using the multicast address “FF00 :: 1001” (channel is N), and other content is multicast distributed using the multicast address “FF00 :: 1002”. (Channel is M) (S911). Then, it is assumed that the network relay apparatus always receives the MPEG2-TS stream distributed by multicast (S912).

  When the receiving device is turned on (YES in S913), first, a JOIN request to a predetermined multicast address “FF00 :: 1001” is transmitted to the network relay device (S914). When receiving the JOIN request (YES in S915), the network relay device starts relaying the MPEG2-TS stream whose channel is N to the receiving device (S916).

  When the receiving apparatus receives an MPEG2-TS stream whose channel is N (S917), the receiving apparatus first detects a TS packet having a PID value of “0”, that is, a PAT, from the stream. The PID is acquired (S918). As described above, since the PAT includes one or more PIDs of the PMT included in the stream, the PMT is detected based on the PAT (S919). Then, the PID of the TS packet storing the video, audio, program time reference value (hereinafter referred to as PCR (Program Clock Reference)), etc. is acquired from the PMT (S919). Next, the acquired PID is set in a video or audio decoder, whereby the content of channel N is reproduced (S920). If the content is encrypted, an ECM is further acquired from the PMT, a decryption key is generated, and the content is decrypted.

When the user gives an instruction to switch the content to be played, for example, an instruction to switch to the content of channel M (YES in S921), the receiving apparatus relays the LEAVE request for the multicast address “FF00 :: 1001” via the network. The data is transmitted to the device (S922). The network relay device that has received the LEAVE request (YES in S923) stops the relay of the content of channel N (S924). The receiving apparatus then transmits a JOIN request to the multicast address “FF00 :: 1002” following the transmission of the LEAVE request (S914), and stores the video, audio, etc. of the content of channel M in the same flow as described above. The PID of the TS packet is acquired and set in the decoder (S915 to S920). Thereby, the content of the channel M is reproduced.
JP 2004-228850 A (publication date: August 12, 2004)

  According to the method disclosed in Patent Document 1, the receiving apparatus exchanges messages before receiving a transport stream, and receives information related to PID in advance. As a result, the content reproduction process can be started without detecting the PAT or PMT, so that the time required until the content reproduction can be shortened.

  However, the method disclosed in Patent Document 1 is premised on content distribution by unicast using RTSP or HTTP. However, as a method for distributing content via a network, there is a method using IP multicast technology as described above, in addition to a unicast distribution method. In the distribution method using IP multicast, message exchange using HTTP or RTSP is not performed. Therefore, the method disclosed in Patent Document 1 has a problem that it cannot be used in content distribution using IP multicast.

  Further, in the method disclosed in Patent Document 1, since it is necessary to include PID information in a response from a device that transmits content in response to a request for video transmission, video and audio are stored in the device that transmits content. It is necessary to introduce a mechanism for exchanging the PID of the TS packet to be received with the receiving apparatus in advance. For this reason, when the system is introduced into an existing system that is already in operation, there is a problem in that it takes time to update the existing system and costs for the update.

  Furthermore, since only the PID of a TS packet storing video and audio can be acquired in advance by the method disclosed in Patent Document 1, for example, an ECM necessary for decrypting encrypted data is obtained. It cannot be acquired. Therefore, when the transport stream includes encrypted data, there is still a problem that decryption processing cannot be performed unless the PMT is analyzed.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to determine the channel without exchanging messages including PID information in advance between the content transmission device and the reception device. Content receiving apparatus, content reproducing apparatus, content receiving / reproducing apparatus, content receiving method, content reproducing method, and content receiving / reproducing method capable of shortening the time required to reproduce the content after switching after receiving the switching instruction Another object of the present invention is to provide a content reproduction system, a program, and a computer-readable recording medium on which the program is recorded.

  In order to solve the above problems, a content receiving apparatus according to the present invention divides at least one of video and audio included in one or a plurality of contents into a plurality of packets, and sets program identification information for identifying the packets and the contents. Packet identification information that can identify each packet is added to the included packet, each packet with the packet identification information added is multiplexed, the stream is received from an external device that transmits as a single stream, and the received stream A content receiving device that is connected to one or more content playback devices that play back the content included in the network via a communication network, and that receives the stream from the external device, the content receiving device receiving the stream from the external device Stream transmission request means for requesting transmission and the requested stream Stream receiving means for receiving the program identification information obtaining means for obtaining the program identification information from the received stream, and packet identification information of the packet included in the received stream is obtained from the acquired program identification information. And a packet identification information transmitting means for transmitting the acquired packet identification information to one or a plurality of the content reproduction devices.

  The content receiving method according to the present invention divides at least one of video and audio included in one or a plurality of contents into a plurality of packets, and each packet is included in a packet including program identification information for identifying the packet and the contents. Assigns identifiable packet identification information, multiplexes each packet with the packet identification information added, receives the stream from an external device that transmits as one stream, and plays back the content contained in the received stream A content reception method executed by a content reception device connected to one or a plurality of content reproduction devices via a communication network and receiving the stream from the external device, wherein the program identification information is obtained from the received stream. Program identification information acquisition step for acquiring the above and the above acquisition A packet identification information acquisition step for acquiring packet identification information of a packet included in the received stream from the received program identification information, and packet identification information for transmitting the acquired packet identification information to one or a plurality of the content reproduction devices. A transmission step.

  According to said structure, program identification information can be acquired from the received stream, packet identification information can be acquired from this acquired program identification information, and this acquired packet identification information can be transmitted to a content reproduction apparatus.

  Therefore, when the content reproduction device that has received the packet identification information decodes a stream received from an external device by itself, the content reproduction device uses the received packet instead of using the packet identification information acquired from the received stream. Since the identification information can be used directly, the process of acquiring the packet identification information from the received stream is not necessary.

  Therefore, the content reproduction apparatus that receives the packet identification information has an effect that the time required from the reception of the stream to the reproduction of the content can be shortened.

  Further, in the content receiving apparatus according to the present invention, in the configuration described above, the packet identification information transmitting unit responds to a request from the content reproduction apparatus, and the packet corresponding to the request is included in the acquired packet identification information. The identification information may be transmitted to the content reproduction apparatus that has made the request.

  According to the above configuration, when there is a request from the content reproduction apparatus, only the packet identification information corresponding to the request can be transmitted to the requested content reproduction apparatus.

  Therefore, since the content receiving apparatus performs the packet identification information transmission process only when there is a request from the content reproduction apparatus, the content receiving apparatus does not need to perform the packet identification information transmission process when there is no request. .

  Accordingly, it is possible to reliably transmit the packet identification information required by the content reproduction device to the requested content reproduction device, and as a result, the content reproduction device receives the stream and reproduces the content. There is an effect that the time required for the process can be shortened. In addition, there is an effect that the load of the transmission process in the content receiving apparatus can be reduced.

  Furthermore, the content receiving device according to the present invention is configured such that, in the above configuration, the stream transmission requesting unit requests the external device to transmit the stream in response to an instruction from the content reproduction device. Also good.

  According to the above configuration, when there is a request from the content reproduction apparatus, it is possible to receive a stream from an external apparatus and acquire packet identification information from the received stream.

  Therefore, the newest packet identification information can be acquired at the timing requested by the content reproduction apparatus, and the acquired packet identification information can be transmitted to the content reproduction apparatus. Therefore, even if the stream delivered from the external device is switched according to the program and the packet identification information is switched accordingly, the stream received by the requested content reproduction device is the device itself. Can be reliably used instead of using the packet identification information acquired from the received stream.

  Therefore, there is an effect that it is possible to reliably reduce the time required from the reception of the stream to the reproduction of the content.

  Furthermore, the content receiving apparatus according to the present invention may be configured such that, in the above configuration, the stream is MPEG2-TS, the program identification information includes PAT and PMT, and the packet identification information is PID.

  According to said structure, PAT and PMT are further acquired from received MPEG2-TS, PID is acquired from this acquired PAT and PMT, and this acquired PID can be transmitted to a content reproduction apparatus.

  Therefore, when the content playback device that has received the PID decodes the MPEG2-TS received from an external device by itself, the content playback device uses the received PID instead of using the PID acquired from the received MPEG2-TS. Can be used directly, so that the process of obtaining the PID from the received MPEG2-TS can be made unnecessary.

  Therefore, it is possible to reduce the time required from the reception of MPEG2-TS to the reproduction of content for one or a plurality of content reproduction devices that have received the PID.

  Furthermore, the content reproduction apparatus according to the present invention divides at least one of video and audio included in one or a plurality of contents into a plurality of packets, and each packet is included in a packet including program identification information for identifying the packet and the contents. Identifiable packet identification information is added, each packet with the packet identification information added is multiplexed, the stream is received from an external device that transmits as one stream, and the program identification information is received from the received stream. And acquiring packet identification information for identifying a packet included in the stream from the acquired program identification information, connected to a content receiving apparatus that transmits the acquired packet identification information via a communication network, and Receive and play the content contained in the received stream A content reproduction apparatus, a packet identification information receiving means for receiving the packet identification information transmitted from the content receiving apparatus, and a decoding processing means for decoding the received stream using the received packet identification information It is characterized by comprising.

  Also, the content reproduction method according to the present invention divides at least one of video and audio included in one or a plurality of contents into a plurality of packets, and each packet is included in a packet including program identification information for identifying the packet and the contents. Identifiable packet identification information is added, each packet with the packet identification information added is multiplexed, the stream is received from an external device that transmits as one stream, and the program identification information is received from the received stream. And acquiring packet identification information for identifying a packet included in the stream from the acquired program identification information, connected to a content receiving apparatus that transmits the acquired packet identification information via a communication network, and Receive and play the content contained in the received stream A content reproduction method executed by a content reproduction device, wherein the packet identification information receiving step receives the packet identification information transmitted from the content reception device, and the received stream using the received packet identification information And a decoding process step for decoding.

  According to said structure, the packet identification information which one or several content receivers transmitted can be received, and the received stream can be decoded using this received packet identification information.

  Therefore, when decoding the received stream, instead of using the packet identification information acquired from the received stream, the received packet identification information can be used directly. The process to acquire can be made unnecessary. In addition, when a plurality of content receiving apparatuses transmit packet identification information, even if the packet identification information transmitted by a certain content receiving apparatus cannot be received, the packet identification information transmitted by another content receiving apparatus is received. If received, the received packet identification information can be used for the decoding process.

  Therefore, by directly using the received packet identification information, there is an effect that it is possible to shorten the time required from the reception of the stream to the reproduction of the content.

  Furthermore, the content reproduction apparatus according to the present invention may further include a packet identification information transmission requesting unit that requests transmission of the packet identification information from one or a plurality of the content reception apparatuses in the above configuration. .

  According to said structure, the transmission request | requirement of packet identification information can be further performed with respect to a content receiver.

  Therefore, a request for transmission of the packet identification information is made to the content receiving device at a timing when the packet identification information is required, and packet identification information transmitted from the content receiving device is received in response to the request. When not performing packet identification information reception processing.

  Therefore, there is an effect that it is possible to reduce the load of the reception process in the content reproduction apparatus.

  Furthermore, the content reproduction apparatus according to the present invention, in the above configuration, has a program identification information acquisition means for acquiring program identification information for identifying each content from the received stream, and the reception from the acquired program identification information. Packet identification information acquisition means for acquiring packet identification information of packets included in the stream, and the packet identification information received by the packet identification information reception means when the decoding processing means decodes the received stream. When the packet identification information cannot be used, the packet identification information acquired by the packet identification information acquisition unit may be used.

  According to the above configuration, the packet identification information acquired from the stream can be used for the decoding process even when the packet identification information received from the content receiving apparatus cannot be used for the stream decoding process.

  Therefore, even when the packet identification information received from the content receiving device cannot be used for stream decoding processing, the content can be reproduced.

  Therefore, the packet receiving information transmitted by the content receiving apparatus can be received, the received packet identifying information can be used to decode the received stream, and the received packet identifying information cannot be used. In addition, there is an effect that the content can be surely reproduced based on the received stream.

  Furthermore, the content playback apparatus according to the present invention may be configured such that, in the above configuration, the stream is MPEG2-TS, the program identification information includes PAT and PMT, and the packet identification information is PID.

  According to the above configuration, the PID transmitted by the content receiving apparatus can be received, and the received MPEG2-TS can be decoded using the received PID.

  Therefore, when the received MPEG2-TS is decoded, the received PID can be used directly instead of using the PID acquired from the received MPEG2-TS. The process to acquire can be made unnecessary.

  Therefore, there is an effect that it is possible to shorten the time required from the reception of MPEG2-TS to the reproduction of the content.

  Furthermore, the content reception / playback apparatus according to the present invention divides at least one of video and audio included in one or a plurality of contents into a plurality of packets, and each packet includes a packet including program identification information for identifying the packet and the contents. Is received, the above-mentioned stream is received from the first external device that multiplexes each packet to which the packet identification information is added and transmits it as one stream, and each content from the received stream The program identification information for identifying the packet is acquired, the packet identification information for identifying the packet included in the stream is acquired from the acquired program identification information, and the acquired packet identification information is used to reproduce the content. A third external device that transmits to the external device and the first external device Content included in the received stream by receiving the stream, receiving the packet identification information transmitted from the third external device, and decoding the received stream using the received packet identification information Is a content reception / playback device that is connected to at least one of the second external devices that reproduces the stream, receives the stream from the first external device, and plays the stream, from the received stream, Program identification information acquisition means for acquiring the program identification information, packet identification information acquisition means for acquiring packet identification information of a packet included in the received stream from the acquired program identification information, and the acquired packet identification information Send packet identification information to one or more second external devices. Means, packet identification information receiving means for receiving packet identification information transmitted from one or more third external devices, and decoding processing for decoding the received stream using the received packet identification information Means.

  Also, the content reception / playback method according to the present invention divides at least one of video and audio included in one or a plurality of contents into a plurality of packets, and each packet includes a packet including program identification information for identifying the packet and the contents. Is received, the above-mentioned stream is received from the first external device that multiplexes each packet to which the packet identification information is added and transmits it as one stream, and each content from the received stream The program identification information for identifying the packet is acquired, the packet identification information for identifying the packet included in the stream is acquired from the acquired program identification information, and the acquired packet identification information is used to reproduce the content. A third external device that transmits to the external device and the first external device to Content included in the received stream by receiving the stream, receiving the packet identification information transmitted from the third external device, and decoding the received stream using the received packet identification information A content reception / playback method executed by a content reception / playback apparatus that is connected to at least one of the second external apparatuses for playing back a stream, receives the stream from the first external apparatus, and plays back the stream. A program identification information acquisition step for acquiring the program identification information from the received stream; and a packet identification information acquisition step for acquiring packet identification information of a packet included in the received stream from the acquired program identification information; The acquired packet identification information is stored in one or more of the second Using the packet identification information transmitting step for transmitting to the external device, the packet identification information receiving step for receiving the packet identification information transmitted from one or more third external devices, and the received packet identification information, A decoding process step for decoding the received stream.

  According to the above configuration, the program identification information is acquired from the received stream, the packet identification information is acquired from the acquired program identification information, the acquired packet identification information is transmitted to the second external device, and Packet identification information can be received from the third external device, and the received stream can be decoded using the received packet identification information.

  Therefore, when the content reproduction apparatus that has received the packet identification information decodes the stream received by the apparatus, the content reproduction apparatus uses the received packet identification information instead of using the packet identification information acquired from the received stream. be able to.

  In addition, when the second external device receiving the packet identification information decodes the stream received by the own device, the second external device uses the received packet identification information instead of using the packet identification information acquired from the received stream. Can be used directly, and thus processing for acquiring packet identification information from the received stream is not necessary.

  Therefore, there is an effect that it is possible to reduce the time required from the reception of the stream to the reproduction of the content. Furthermore, the second external device that receives the packet identification information has an effect that the time required from the reception of the stream to the reproduction of the content can be shortened.

  Furthermore, a content reproduction system according to the present invention includes the content reception device and the content reproduction device.

  According to the above configuration, the content receiving apparatus acquires program identification information from the received stream, acquires packet identification information from the acquired program identification information, and transmits the acquired packet identification information to the content reproduction apparatus. In addition, the content reproduction apparatus that has received the packet identification information can use the received packet identification information when decoding a stream received by the apparatus.

  Therefore, when the content reproduction device that has received the packet identification information from the content reception device decodes the stream received by itself, the content reproduction device uses the received packet instead of using the packet identification information acquired from the received stream. Since the identification information can be used directly, the process of acquiring the packet identification information from the received stream is not necessary.

  Therefore, the content reproduction device that receives the packet identification information from the content reception device can shorten the time required from the reception of the stream to the reproduction of the content.

  Furthermore, a content reproduction system according to the present invention is characterized by comprising at least one content receiving / reproducing apparatus.

  According to the above configuration, the content reception / playback apparatus acquires program identification information from the received stream, acquires packet identification information from the acquired program identification information, and plays back the content using the acquired packet identification information. The other apparatus that has transmitted the packet identification information and has received the packet identification information can use the received packet identification information when decoding the stream received by the own apparatus. Further, it is possible to receive packet identification information from another device that transmits packet identification information, and to decode the received stream using the received packet identification information.

  Therefore, when the other device that reproduces the content decodes the stream received by itself, it directly uses the received packet identification information instead of using the packet identification information acquired from the received stream. Therefore, it is not necessary to acquire packet identification information from the received stream.

  Further, when the content reception / playback apparatus that has received the packet identification information decodes the stream received by itself, the content reception / playback apparatus directly uses the received packet identification information instead of using the packet identification information acquired from the received stream. Can be used.

  Therefore, it is possible to reduce the time required for the device that reproduces the content to receive the stream until the content is reproduced.

  The content receiving device, the content reproducing device, and the content receiving / reproducing device may be realized by a computer. In this case, the content receiving device, the content reproducing device are operated by causing the computer to operate as each unit. An apparatus, the content receiving apparatus for realizing the content receiving / reproducing apparatus by a computer, the content reproducing apparatus, a control program for the content receiving / reproducing apparatus, and a computer-readable recording medium recording the same are also included in the scope of the present invention. enter.

  As described above, the content receiving apparatus according to the present invention divides at least one of video and audio included in one or a plurality of contents into a plurality of packets, and converts the packets and packets including program identification information for identifying the contents. Packet identification information that can be identified by each packet is added, each packet with the packet identification information added is multiplexed, and the stream is received from an external device that transmits as one stream, and is included in the received stream A content receiving apparatus that is connected to one or a plurality of content reproducing apparatuses that reproduce contents via a communication network and receives the stream from the external apparatus, and requests the external apparatus to transmit the stream Stream transmission requesting means for receiving and receiving the requested stream A stream receiving means; a program identification information obtaining means for obtaining the program identification information from the received stream; and a packet identification for obtaining packet identification information of a packet included in the received stream from the obtained program identification information. Information acquisition means and packet identification information transmission means for transmitting the acquired packet identification information to one or a plurality of the content reproduction devices.

  The content receiving method according to the present invention divides at least one of video and audio included in one or a plurality of contents into a plurality of packets, and each packet is included in a packet including program identification information for identifying the packet and the contents. Assigns identifiable packet identification information, multiplexes each packet with the packet identification information added, receives the stream from an external device that transmits as one stream, and plays back the content contained in the received stream A content reception method executed by a content reception device connected to one or a plurality of content reproduction devices via a communication network and receiving the stream from the external device, wherein the program identification information is obtained from the received stream. Program identification information acquisition step for acquiring the above and the above acquisition A packet identification information acquisition step for acquiring packet identification information of a packet included in the received stream from the received program identification information, and packet identification information for transmitting the acquired packet identification information to one or a plurality of the content reproduction devices. A transmission step.

  Therefore, the content playback apparatus that has received the packet identification information directly uses the received packet identification information instead of using the packet identification information acquired from the received stream when decoding the stream received by the apparatus. Therefore, it is not necessary to acquire packet identification information from the received stream.

  Therefore, the content reproduction apparatus that receives the packet identification information has an effect that the time required from the reception of the stream to the reproduction of the content can be shortened.

  In the embodiment, when a specific example is described, a mode in which video content is distributed via a communication network and a channel is switched between the content reception device and the content reproduction device will be described. Of course, it is not limited to this. For example, the content to be distributed may not be video content but audio-only content.

  Further, in the embodiment, when a specific example is described, a description will be given of a form in which the communication network is constructed by IP (Internet Protocol), but the present invention is not limited to this. For example, it may be constructed by IPX (Internet Packet eXchange) or Apple Talk.

  Also, in the embodiment, when a specific example is described, a mode in which video content is stream-distributed using the IP multicast technology will be described, but the present invention is not limited to this. For example, distribution using unicast such as RTSP may be used.

  Further, in the embodiment, when a specific example is described, an embodiment in which the transport format of video content to be distributed is MPEG2-TS will be described, but the present invention is not limited to this.

[Embodiment 1]
An embodiment of the present invention will be described below with reference to FIGS.

(Overall configuration of content playback system)
A content reproduction system 100a including a content reproduction device 103a and a content reception device 105a according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration of a content reproduction system 100a including the content reproduction device 103a and the content reception device 105a according to the present embodiment.

  As shown in FIG. 2, the content transmission apparatus 101 and the network relay apparatus 102 are communicably connected via a communication network 1110. Further, the network relay device 102 and the content reproduction device 103a are communicably connected via a communication network 1120. Similarly, the network relay device 102 and the content receiving device 105a are connected to be communicable via a communication network 1120.

  The content transmission device 101 is a server device that distributes content such as broadcast, moving image, still image, text, and video content including attribute information related to display and control thereof. Then, the content is distributed to the content reproduction device 103a and the content reception device 105a using the IP multicast technology.

  The network relay device 102 is a network relay device (for example, a broadband router), and enables the communication network 1110 and the communication network 1120 to be connected to each other. The network relay device 102 supports IP multicast JOIN and LEAVE, and communicates various data distributed by the IP multicast from the communication network 1110 according to the JOIN request and LEAVE request from the device on the communication network 1120 side. A function for determining whether to relay to the network 1120 side is provided.

  The content playback apparatus 103a according to the present embodiment is a client that plays back video content distributed via the communication network 1110 and the communication network 1120. Further, the content reproduction apparatus 103a may receive an input from a user by an input operation device such as a remote controller. The content playback device 103a is, for example, a television, a PC, a mobile phone, a PDA (Personal Digital Assistant), or the like.

  The content receiving apparatus 105a according to the present embodiment is a client that receives video content distributed via the communication network 1110 and the communication network 1120, but does not have a playback function. The content receiving device 105a is, for example, a network compatible hard disk recorder or tuner device.

  In this embodiment, the communication network 1110 is assumed to be the Internet, and the communication network 1120 is assumed to be a LAN. However, the present invention is not particularly limited, and examples thereof include an intranet, an extranet, an ISDN, a VAN, and a CATV communication network. A virtual private network, a telephone line network, a mobile communication network, etc. can be used. Also, the transmission medium constituting the communication network is not particularly limited, and for example, an infrared ray such as IrDA, Bluetooth (Bluetooth) (IEEE1394 cable, USB cable, power line carrier, cable TV line, telephone line, ADSL line, etc.) (Registered trademark), 802.11 wireless, HDR, mobile phone network and the like can also be used.

(Configuration of content receiving device)
Next, the configuration of the content receiving apparatus 105a according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of content receiving apparatus 105a according to the present embodiment.

  As shown in FIG. 1, the content receiving apparatus 105 a includes a control unit 10, a storage unit 20, a communication unit 30, an input operation unit 60, and an input / output control unit 70.

  The control unit 10 controls the storage unit 20 and the input / output control unit 70 and performs predetermined arithmetic processing. Examples of the predetermined arithmetic processing include reception processing of a video stream from the network relay apparatus 102. The detailed configuration of the control unit 10 will be described later.

  The storage unit 20 stores various data used by the control unit 10, data obtained by executing a program, and the like, and is realized by a non-volatile memory such as a ROM (Read-Only Memory) or a flash memory. The The various data is stored in various storage units inside the storage unit 20, for example, the PID information storage unit 22 or the like.

  The PID information storage unit 22 has various PIDs acquired from the received video stream (PID of PMT, PID of TS packet storing video, PID of TS packet storing audio, PID of TS packet storing PCR, etc.) The information is memorized.

  The storage unit 20 is not necessarily provided in the content receiving device 105a, and may be configured as an external storage device connected to the content receiving device 105a in a readable state.

  The communication unit 30 communicates with the network relay apparatus 102 via the communication network 1120 and includes a reception unit 31 and a transmission unit 32 therein.

  The receiving unit 31 receives the video stream transmitted from the network relay apparatus 102 and is controlled by the reception control unit 71. The video stream received by the receiving unit 31 is sent to the reception control unit 71.

  The reception control unit 71 controls the reception unit 31 and transmits the received video stream to the video stream reception unit 12 described later.

  The transmission unit 32 transmits an IGMP JOIN request and a LEAVE request to the network relay device 102, and transmits a PID list 450 (described later) to the content reproduction device 103a. 72.

  The transmission control unit 72 controls the transmission unit 32 to receive a JOIN request received from the video stream transmission request unit 11 described later, a LEAVE request received from the video stream transmission stop request unit 15, and a PID list received from the PID information transmission unit 17. 450 is transmitted to the transmission unit 32.

  The input operation unit 60 receives a user operation and transmits a signal corresponding to the input operation to the input operation control unit 76. The input operation unit 60 includes input devices such as a remote controller, a mouse, a keyboard, a switch, and a touch panel, for example. When the user performs an input operation from the input operation unit 60, a signal corresponding to the input operation such as a video stream reception start instruction is generated. The input operation unit 60 is not necessarily provided in the content receiving device 105a, and may be configured to be communicably connected to the content receiving device 105a as an external device.

  The input operation control unit 76 controls the input operation unit 60 that receives a user operation, and transmits a signal corresponding to the user's input operation to the control unit 10.

  Next, the control unit 10 will be described in detail. The control unit 10 includes a video stream transmission request unit 11, a video stream reception unit 12, a program identification information acquisition unit 13, a PID information acquisition unit 14, a video stream transmission stop request unit 15, a PID information inspection unit 16, and a PID information transmission unit 17. Is included.

  The video stream transmission request unit 11 transmits a JOIN request for requesting relay of the video stream to the network relay apparatus 102. The timing for transmitting the JOIN request is, for example, immediately after receiving a signal from the PID information inspection unit 16 indicating that PID information has not been acquired for all channels.

  The video stream receiving unit 12 receives the video stream transmitted from the network relay apparatus 102 in response to the JOIN request via the receiving unit 31. Then, the received video stream is transmitted to the program identification information acquisition unit 13.

  The program identification information acquisition unit 13 analyzes the video stream received from the video stream reception unit 12 and acquires PAT and PMT which are program identification information. Then, the acquired PMT is transmitted to the PID information acquisition unit 14.

  The PID information acquisition unit 14 analyzes the PMT transmitted from the program identification information acquisition unit 13, and displays the PID of the TS packet storing video, the PID of the TS packet storing audio, the PID of the TS packet storing PCR, and the like. get. These acquired PIDs are stored in the PID information storage unit 22 for each channel number.

  The video stream transmission stop request unit 15 transmits a LEAVE request for requesting the network relay device 102 to stop relaying the received video stream. The timing at which the LEAVE request is transmitted is, for example, immediately after the PID information acquisition unit 14 stores the acquired PID in the PID information storage unit 22.

  The PID information inspecting unit 16 inspects whether the PID information acquiring unit 14 has acquired the acquired PID in the PID information storing unit 22 and has acquired PID information for all channels. When it is detected that PID information has not been acquired for all channels, the fact is transmitted to the video stream transmission requesting unit 11. On the other hand, if it is detected that PID information has been acquired for all channels, a message to that effect is transmitted to the PID information transmitting unit 17.

  When the PID information transmission unit 17 receives a signal indicating that PID information has been acquired for all channels from the PID information inspection unit 16, the PID information transmission unit 17 uses a PID stored in the PID information storage unit 22 to A list 450 is generated. Then, the created PID list 450 is transmitted to the content reproduction apparatus 103a via the transmission unit 32. As a transmission method of the PID list 450, for example, an IP broadcast address may be designated and transmitted to all clients in the same subnet mask at the same time, or a client designated in advance (that is, a content reproduction apparatus) 103a) may be transmitted to the IP address.

  In the above-described embodiment, the form in which the acquired PID is stored in the PID information storage unit 22 has been described. However, the present invention is not limited to this. For example, a temporary internal file in the control unit 10 may be created and described in the internal file every time a PID is acquired. Then, the PID information transmission unit 17 may generate the PID list 450 based on the internal file.

(Configuration of content playback device)
Next, the configuration of the content reproduction apparatus 103a according to the present embodiment will be described with reference to FIG. FIG. 3 is a block diagram showing a configuration of the content reproduction apparatus 103a according to the present embodiment.

  As shown in FIG. 3, the content reproduction apparatus 103a includes a control unit 110, a storage unit 120, a communication unit 130, a display unit 140, an audio output unit 150, an input operation unit 160, and an input / output control unit 170. .

  The control unit 110 controls the storage unit 120 and the input / output control unit 170 and performs predetermined arithmetic processing. Examples of the predetermined arithmetic processing include reception processing of a video stream from the network relay apparatus 102. A detailed configuration of the control unit 110 will be described later.

  The storage unit 120 stores various data used by the control unit 110, data obtained by executing a program, and the like, and is realized by a nonvolatile memory such as a ROM or a flash memory. The various data are stored in various storage units inside the storage unit 120, such as the PID information storage unit 122.

  The PID information storage unit 122 stores information of various PIDs (PID of PMT, PID of TS packet storing video, PID of TS packet storing audio, PID of TS packet storing PCR, etc.).

  Note that the storage unit 120 is not necessarily provided in the content reproduction device 103a, and may be configured as an external storage device that is connected to the content reproduction device 103a in a readable state.

  The communication unit 130 communicates with the network relay apparatus 102 via the communication network 1120 and includes a reception unit 131 and a transmission unit 132 therein.

  The receiving unit 131 receives the video stream transmitted from the network relay device 102 and the PID list 450 transmitted from the content receiving device 105a, and is controlled by the reception control unit 171. The video stream and PID list 450 received by the receiving unit 131 are sent to the reception control unit 171.

  The reception control unit 171 controls the reception unit 131 and transmits the received video stream to the video stream reception unit 113 described later. Also, the received PID list 450 is transmitted to the PID information receiving unit 111 described later.

  The transmission unit 132 transmits an IGMP JOIN request and a LEAVE request to the network relay apparatus 102, and is controlled by the transmission control unit 172.

  The transmission control unit 172 controls the transmission unit 132 to transmit a JOIN request received from the video stream transmission request unit 112 described later and a LEAVE request received from the video stream transmission stop request unit 119 to the transmission unit 132.

  The display unit 140 displays information sent from the display control unit 174. The display unit 140 is configured by, for example, an LCD (Liquid Crystal Display). The information displayed on the display unit 140 includes a video decoded by the decoding unit 115 described later. The display unit 140 is not necessarily provided in the content reproduction device 103a, and may be configured to be communicably connected to the content reproduction device 103a as an external device.

  The display control unit 174 controls the display unit 140 and transmits information instructed from the control unit 110 to the display unit 140.

  The sound output unit 150 converts the signal transmitted from the sound output control unit 175 into sound and outputs the sound. The audio output unit 150 is configured by a speaker, for example. Information output to the audio output unit 150 includes audio decoded by the decoding unit 115 described later. The audio output unit 150 is not necessarily provided in the content reproduction device 103a, and may be configured to be communicably connected to the content reproduction device 103a as an external device.

  The audio output control unit 175 controls the audio output unit 150 and transmits information instructed from the control unit 110 to the audio output unit 150.

  The input operation unit 160 receives a user operation and transmits a signal corresponding to the input operation to the input operation control unit 176. The input operation unit 160 is composed of input devices such as a remote controller, a mouse, a keyboard, a switch, and a touch panel, for example. When the user performs an input operation from the input operation unit 160, a signal corresponding to an input operation such as a video stream reception start instruction or a video stream switching instruction is generated. The input operation unit 160 is not necessarily provided in the content reproduction device 103a, and may be configured to be communicably connected to the content reproduction device 103a as an external device.

  The input operation control unit 176 controls the input operation unit 160 that accepts a user operation, and transmits an input signal corresponding to the user's input operation to the control unit 110.

  Next, the control unit 110 will be described in detail. The control unit 110 includes a PID information reception unit 111, a video stream transmission request unit 112, a video stream reception unit 113, a reproduction processing unit 114, a decoding unit 115, and a video stream transmission stop request unit 119.

  The PID information receiving unit 111 receives the PID list 450 including the PID of the TS packet storing the video and the PID of the TS packet storing the audio from the content receiving apparatus 105a via the receiving unit 131. Then, the PID described in the received PID list 450 is stored in the PID information storage unit 122. These PIDs are used as PIDs set in the decoding unit 115.

  The video stream transmission request unit 112 transmits a JOIN request for requesting relay of the video stream to the network relay apparatus 102. The timing for transmitting the JOIN request is, for example, after the PID information receiving unit 111 receives the PID list 450, and according to an input operation such as a video stream reception start instruction or a channel switching instruction from the input operation unit 160. When a signal is received.

  The video stream reception unit 113 receives the video stream transmitted from the network relay apparatus 102 in response to the JOIN request via the reception unit 131. Then, the received video stream is transmitted to the reproduction processing unit 114.

  When the PID information stored in the PID information storage unit 122 is valid, the reproduction processing unit 114 sets the PID in the decoding unit 115 and decodes the video stream received from the video stream receiving unit 113. 115 to instruct reproduction. On the other hand, when the PID information stored in the PID information storage unit 122 is not valid, the video stream received from the video stream receiving unit 113 is analyzed, the PAT and the PMT are acquired, the PMT is further analyzed, and the video is The PID of the TS packet to be stored, the PID of the TS packet that stores the voice, and the PID of the TS packet that stores the PCR are acquired. Then, the obtained PID is set in the decoding unit 115, and the video stream received from the video stream receiving unit 113 is transmitted to the decoding unit 115, and a reproduction instruction is given.

  As a method for determining whether or not the PID information is valid, for example, when the content reproduction apparatus 103a holds program guide information, the program is switched based on the determination from the time when the PID is acquired. If the PID information is valid, the PID information may be determined to be invalid if the program is not switched.

  Based on the video stream and PID information received from the playback processing unit 114, the decoding unit 115 decodes video and audio using a general method. Then, the decoded video and audio are transmitted to the display unit 140. For this purpose, the decoding unit 115 includes a multiplexing division unit 116, a video decoding unit 117, and an audio decoding unit 118.

  The multiplexing / dividing unit 116 divides the multiplexed video stream into individual video and audio using a general method based on the video stream and PID information transmitted from the reproduction processing unit. Then, the divided video and audio are transmitted to the video decoding unit 117 and the audio decoding unit 118, respectively.

  The video decoding unit 117 decodes the video transmitted from the multiplexing / dividing unit 116 using a general method, and transmits the video to the display unit 140 via the display control unit 174. In addition, the audio decoding unit 118 decodes the audio transmitted from the multiplexing and dividing unit 116 using a general technique, and transmits the decoded audio to the display unit 140 via the display control unit 174.

  The video stream transmission stop request unit 119 transmits a LEAVE request for requesting the network relay apparatus 102 to stop relaying the received video stream. The timing for transmitting the LEAVE request is, for example, when a signal corresponding to an input operation such as a channel switching instruction is received from the input operation unit 160.

  In the above-described embodiment, the received PID list 450 is stored in the PID information storage unit 122. However, the present invention is not limited to this. For example, the received PID list 450 may be held in a temporary storage area in the control unit 110. Then, the reproduction processing unit 114 may perform processing based on the PID list 450 instead of the PID information stored in the PID information storage unit 122.

(Processing flow until content playback)
Next, with reference to FIG. 4 and FIG. 5, a procedure in which the content reproduction device 103a reproduces content transmitted from the network relay device 102 based on the PID list 450 transmitted from the content reception device 105a will be described. .

(Processing flow in content receiving device)
First, with reference to FIG. 4, a procedure in which the content receiving apparatus 105a acquires PIDs for all channels from the content transmitting apparatus 101 in advance via the network relay apparatus 102 and transmits the PID to the content reproducing apparatus 103a. explain. FIG. 4 is a flowchart showing a flow in which the content receiving apparatus 105a acquires PIDs for all channels from the content transmitting apparatus 101 in advance via the network relay apparatus 102 and transmits them to the content reproducing apparatus 103a.

  In FIG. 4, it is assumed that a plurality of contents are multicast distributed from the content transmission apparatus 101. For example, a certain content is multicasted using the multicast address “FF00 :: 1001” (channel number is N), and another content is multicasted using the multicast address “FF00 :: 1002”. (Channel number is M) (S411). Then, it is assumed that the network relay apparatus 102 always receives the MPEG2-TS stream distributed by multicast (S412).

  When power is turned on at content receiving apparatus 105a (YES at S413), first, PID information inspection unit 16 of content receiving apparatus 105a has acquired all PIDs of receivable channel contents. (S414). Here, since no PID has been acquired immediately after the power is turned on (YES in S414), the video stream transmission request unit 11 of the content receiver 105a selects a predetermined channel and selects the selected channel. A JOIN request for the multicast address corresponding to the selected channel is transmitted to the network relay apparatus 102 (S415).

  When the network relay apparatus 102 receives the JOIN request (YES in S416), the network relay apparatus 102 relays the transport stream of the content distributed by the multicast address corresponding to the JOIN request to the content receiving apparatus 105a (S417). ).

  Then, when the video stream receiving unit 12 of the content receiving apparatus 105a receives the MPEG2-TS stream of the content (S418), the program identification information acquiring unit 13 first sets the PID value “ The TS packet that is “0”, that is, the PAT is detected, and the PID of the PAT is acquired (S419 (program identification information acquisition step)). As described above, the PAT includes one or more PMT PIDs included in the stream. Therefore, the PMT is detected based on the PAT, and the PID information acquisition unit 14 detects video, audio from the PMT. The PID of the TS packet storing PCR (Program Clock Reference) and the like is acquired (S420 (packet identification information acquisition step)). Then, the acquired PID is stored in the PID information storage unit 22.

  Thereafter, the video stream transmission stop request unit 15 of the content receiving apparatus 105a transmits a LEAVE request for stopping the reception of the received content to the network relay apparatus 102 (S421). The network relay apparatus 102 that has received the LEAVE request (YES in S422) stops relaying the content transport stream (S423).

  Then, following the transmission of the LEAVE request, the content receiving apparatus 105a repeats the above processing until it acquires the PIDs of TS packets that store video, audio, PCR, etc. of all selectable channels (S415 to S421). .

  When acquisition of PIDs for all channels is completed (NO in S414), PID information transmission unit 17 generates PID list 450 based on the PIDs stored in PID information storage unit 22, and the content playback device 103a (S424 (packet identification information transmission step)). As a transmission method of the PID list 450, for example, an IP broadcast address may be designated and transmitted to all clients in the same subnet mask at the same time, or a client designated in advance (that is, a content reproduction apparatus) 103a) may be transmitted to the IP address.

  Then, after transmitting the PID list 450, the content receiving apparatus 105a stands by until a predetermined time elapses (NO in S425), and when the predetermined time elapses (YES in S425), the receivable channel is again received. The process of acquiring all the PIDs of the content and transmitting the PID list 450 is repeated (S414 to S425).

  In the above description, the mode of performing the reacquisition after the elapse of a predetermined time has been described as the timing for reacquiring the PID again. However, the present invention is not limited to this. For example, when the content receiving device 105a acquires electronic television program guide information from an external device (not shown) via the communication network 1120 in advance, the channel to be viewed is switched by a user operation on the electronic television program guide. Alternatively, the PID may be reacquired at the same timing.

(Processing flow in content playback device)
Next, with reference to FIG. 5, a description will be given of a procedure in which the content reproduction device 103a reproduces content based on the PID list obtained from the content reception device 105a. FIG. 5 is a flowchart showing a flow in which the content reproduction device 103a reproduces content based on the PID list obtained from the content reception device 105a.

  Note that each step in the content transmission apparatus 101 and the network relay apparatus 102 performs the same processing as each step shown in FIG. 4, and therefore, for convenience of explanation, the same reference numeral is added and the explanation is omitted.

  When power is turned on in content reproduction apparatus 103a (YES in S611), first, PID information reception unit 111 receives PID list 450 transmitted by content reception apparatus 105a (S612 (packet identification information reception)). Step)). Then, the PID of the TS packet storing the video, audio, PCR, etc. described in the acquired PID list 450 is stored in the PID information storage unit 122.

  Next, when a channel is selected by a user operation or the like to the input operation unit 160, the video stream transmission request unit 112 transmits a JOIN request to the multicast address for the channel to the network relay device 102 (S613).

  When the video stream receiving unit 113 receives the MPEG2-TS stream corresponding to the JOIN request (S614), the reproduction processing unit 114 stores the video, audio, and PCR of the channel stored in the PID information storage unit 122. Are set in the decoding unit 115, and the received video stream is input to the decoding unit 115 (S615 (decoding processing step)). The decoded video and audio are reproduced on the display unit 140.

  Then, the content reproduction apparatus 103a waits until there is a channel switching instruction from the user (NO in S616). Then, when there is a channel switching instruction (YES in S616), the video stream transmission stop request unit 119 sends a LEAVE request to stop the currently received channel stream (S617).

  Then, the video stream transmission request unit 112 transmits the JOIN request again to the newly designated channel (S613), and performs the above processes to reproduce video and audio (S614, S615).

(PID list)
Next, the data structure of the PID list 450 will be described with reference to FIG. FIG. 6A is a diagram schematically showing the data structure of the PID list 450. As shown in FIG. 6A, the PID list 450 includes channel numbers 4501 and PID numbers 4502 to 4505. Furthermore, a plurality of sets of channel numbers 4501 and PID numbers 4502 to 4505 are included.

  A channel number 4501 indicates a number for identifying each channel. PID numbers 4502 to 4505 indicate PID numbers of TS packets storing PMT, video, audio, and PCR included in the channel.

  Although the description has been given here assuming that there are four types of PIDs (that is, PID numbers 4502 to 4505), the number is not limited to four.

  Next, a specific description example of the PID list 450 will be described with reference to FIG. FIG. 6B is a diagram illustrating a specific description example of the PID list 450. As shown in FIG. 6B, this PID list 450 indicates that “Channel 1” and “Channel 2” are included as channels. The PID included in “Channel 1” is PMT_PID (value is 50), “Audio_PID” (value is 100), “Video_PID” (value is 101), and “PCR_PID” (value is 101). Yes. Further, the PIDs included in “Channel 2” are PMT_PID (value is 51), “Audio_PID” (value is 200), “Video_PID” (value is 201), and “PCR_PID” (value is 201). Show.

(Modification)
In the above description, a mode has been described in which the PID list 450 including all PIDs is unilaterally transmitted from the content receiving apparatus 105a to the content reproduction apparatus 103a by IP multicast. However, the method for transmitting the PID list 450 is not limited to the above. For example, the content receiving apparatus 105a may transmit the PID list 450 in accordance with a request from the content reproduction apparatus 103a. Specifically, an HTTP GET request may be transmitted from the content reproduction apparatus 103a, and the content reception apparatus 105a may transmit a PID list 450 as a response thereto.

  A description example of the HTTP GET request and its response will be described with reference to FIGS. 7 (a) and 7 (b). FIG. 7A is a diagram schematically illustrating a description example of the HTTP GET request. FIG. 7B is a diagram schematically illustrating a description example of a response to the request.

  As shown in FIG. 7A, in the HTTP GET request, the PID list in the content receiving apparatus 105a is specified as the URL “http: //reciver1/pid_list.txt”. 7B, the HTTP response describes the contents of the PID list 450 described in FIG. 5B.

  As described above, the content receiving apparatus 105a according to the present embodiment receives video streams of all selectable channels, acquires PIDs of TS packets storing video, audio, PCR, and the like from the video streams, The PID list 450 is transmitted to the playback device 103a. In addition, the content reproduction apparatus 103a in the present embodiment receives the PID list 450 transmitted from the content reception apparatus 105a, and stores TS packets that store video, audio, PCR, and the like described in the received PID list 450. Based on the PID, the decoding process is performed to reproduce the content.

  As a result, the content reproduction apparatus 103a can acquire all PIDs in advance, and therefore, it is not necessary to individually acquire PIDs from the content transmission apparatus 101 after receiving a channel change instruction from the user. Therefore, it is possible to reduce the time required from when the channel switching instruction is received from the user until the content after switching is played back.

[Embodiment 2]
In the first embodiment, the mode in which the PID list 450 including all PIDs is transmitted from the content receiving apparatus 105a to the content reproduction apparatus 103a by IP multicast has been described. However, the method for transmitting the PID list 450 is not limited to the above.

  Therefore, in the present embodiment, a mode in which the content receiving apparatus transmits only the PID information requested by the content reproduction apparatus will be described. In brief, the content reproduction apparatus transmits an HTTP GET request for requesting PID information. On the other hand, the content receiving apparatus transmits corresponding PID information as a response.

  An embodiment of the present invention will be described below with reference to FIGS. For convenience of explanation, members having the same functions as those shown in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

(Overall configuration of content playback system)
A content reproduction system 100b including a content reproduction device 103b and a content reception device 105b according to the present embodiment will be described with reference to FIG. FIG. 8 is a block diagram showing a configuration of a content reproduction system 100b including the content reproduction device 103b and the content reception device 105b, the content transmission device 101, and the network relay device 102 according to the present embodiment.

  Similar to the content playback device 103a, the content playback device 103b is a client that plays back video content distributed via the communication network 1110 and the communication network 1120.

  Similar to the content receiver 105a, the content receiver 105b is a client that receives video content distributed via the communication network 1110 and the communication network 1120, but does not have a playback function.

(Configuration of content receiving device)
Next, the configuration of the content receiving apparatus 105b according to the present embodiment will be described with reference to FIG. FIG. 9 is a block diagram showing a configuration of content receiving apparatus 105b according to the present embodiment.

  As illustrated in FIG. 9, the content reception device 105 b includes substantially the same members as the content reception device 105 a according to the first embodiment, but includes a communication unit 30 b instead of the communication unit 30. Further, an input / output control unit 70 b is provided instead of the input / output control unit 70. Further, a control unit 10 b is provided instead of the control unit 10.

  The communication unit 30b includes substantially the same members as the communication unit 30 of the first embodiment, but includes a reception unit 31b instead of the reception unit 31. Further, a transmission unit 32 b is provided instead of the transmission unit 32.

  In addition to receiving the video stream transmitted from the network relay device 102, the reception unit 31b receives a PID request command 451 (described later) transmitted from the content reproduction device 103b. The video stream and PID request command 451 received by the reception unit 31b are sent to the reception control unit 71b.

  The transmission unit 32b transmits an IGMP JOIN request and a LEAVE request to the network relay device 102, and transmits a PID response response 452 (described later) to the content reproduction device 103b.

  The input / output control unit 70 b includes substantially the same members as the input / output control unit 70 of the first embodiment, but includes a reception control unit 71 b instead of the reception control unit 71. Further, a transmission control unit 72b is provided instead of the transmission control unit 72.

  The reception control unit 71b controls the reception unit 31b to transmit the received video stream to the video stream reception unit 12, and also transmits the received PID request command 451 to the PID request reception unit 91 described later.

  The transmission control unit 72b controls the transmission unit 32b, and in addition to the JOIN request received from the video stream transmission request unit 11 and the LEAVE request received from the video stream transmission stop request unit 15, the PID response received from the PID information transmission unit 17b The response 452 is transmitted to the transmission unit 32b.

  The control unit 10b includes substantially the same members as the control unit 10 of the first embodiment, but newly includes a PID request reception unit 91. Further, instead of the PID information transmission unit 17, a PID information transmission unit 17b is provided.

  The PID request receiving unit 91 receives the PID request command 451 transmitted from the content reproduction device 103b via the receiving unit 31b. Then, a signal to generate the PID requested by the PID request command 451 is transmitted to the PID information transmitting unit 17b.

  The PID information transmission unit 17b receives a signal indicating that PID information has been acquired for all channels from the PID information inspection unit 16. Then, when receiving a signal from the PID request receiving unit 91 after the reception, the PID requested by the received PID request command 451 is acquired from the PID information storage unit 22. Then, a PID response response 452 including the acquired PID is generated and transmitted to the content reproduction device 103b via the transmission unit 32b.

  In the above-described embodiment, the form in which the PID response response 452 is generated based on the PID stored in the PID information storage unit 22 has been described. However, the present invention is not limited to this. For example, as described in the first embodiment, the PID information transmission unit 17b may generate the PID response response 452 based on the PID information held as a temporary internal file in the control unit 10b.

(Configuration of content playback device)
Next, the configuration of the content reproduction apparatus 103b according to the present embodiment will be described with reference to FIG. FIG. 10 is a block diagram showing a configuration of content reproduction apparatus 103b according to the present embodiment.

  As shown in FIG. 10, the content reproduction device 103 b includes substantially the same members as the content reproduction device 103 a of Embodiment 1, but includes a communication unit 130 b instead of the communication unit 130. Further, an input / output control unit 170b is provided instead of the input / output control unit 170. Further, a control unit 110 b is provided instead of the control unit 110.

  The communication unit 130b includes substantially the same members as the communication unit 130 of the first embodiment, but includes a reception unit 131b instead of the reception unit 131. Further, a transmission unit 132 b is provided instead of the transmission unit 132.

  In addition to receiving the video stream transmitted from the network relay device 102, the reception unit 131b receives the PID response response 452 transmitted from the content reception device 105b. The video stream and PID response response 452 received by the reception unit 131b are sent to the reception control unit 171b.

  The transmission unit 132b transmits a PID request command 451 to the content reception apparatus 105b in addition to transmitting an IGMP JOIN request and a LEAVE request to the network relay apparatus 102.

  The input / output control unit 170b includes substantially the same members as the input / output control unit 170 of the first embodiment, but includes a reception control unit 171b instead of the reception control unit 171. Further, a transmission control unit 172b is provided instead of the transmission control unit 172.

  The reception control unit 171b controls the reception unit 131b to transmit the received video stream to the video stream reception unit 113, and transmits the received PID response response 452 to the PID information reception unit 111b described later.

  The transmission control unit 172b controls the transmission unit 132b, and in addition to the JOIN request received from the video stream transmission request unit 112b and the LEAVE request received from the video stream transmission stop request unit 119, the PID request received from the PID information request unit 92 The command 451 is transmitted to the transmission unit 132b.

  The control unit 110b includes substantially the same members as the control unit 110 of the first embodiment, but newly includes a PID information request unit 92. Further, instead of the PID information receiving unit 111, a PID information receiving unit 111b is provided. Further, in place of the video stream transmission request unit 112, a video stream transmission request unit 112b is provided.

  The PID information request unit 92 receives the PID of the TS packet storing the video, audio, PCR, and the like in the channel of the video stream that the video stream transmission request unit 112b requests the network relay device 102 to relay from the content receiving device 105b. In order to obtain it, a PID request command 451 for requesting those PIDs is generated. Then, the generated PID request command 451 is transmitted to the transmission control unit 172b.

  As a response to the PID request command 451 generated by the PID information requesting unit 92, the PID information receiving unit 111b receives the PID response response 452 transmitted by the content receiving device 105b via the receiving unit 131b. Then, the PID included in the received PID response response 452 is stored in the PID information storage unit 122. These PIDs are used as PIDs set in the decoding unit 115.

  The video stream transmission request unit 112b transmits a JOIN request for requesting the relay of the video stream to the network relay apparatus 102. The timing for transmitting the JOIN request is, for example, immediately after the content reproduction apparatus 103b is turned on or when a signal corresponding to an input operation such as a video stream reception start instruction or a channel switching instruction is received from the input operation unit 160. is there. Then, after transmitting the JOIN request, the PID information requesting unit 92 is notified of the requested channel.

  In the above-described embodiment, the PID described in the received PID response response 452 is stored in the PID information storage unit 122. However, the present invention is not limited to this. For example, the received PID information may be held in a temporary storage area in the control unit 110b. Then, instead of the PID information stored in the PID information storage unit 122, the reproduction processing unit 114 may perform processing based on temporarily held PID information.

(Processing flow until content playback)
Next, with reference to FIG. 11 and FIG. 12, a description will be given of a procedure in which the content reproduction device 103b reproduces content transmitted from the network relay device 102 after requesting a necessary PID from the content reception device 105b. To do.

(Processing flow in content playback device)
First, a procedure for reproducing content based on the PID information requested from the content receiving device 105b by the content reproducing device 103b will be described with reference to FIG. FIG. 11 is a flowchart showing a flow in which the content reproduction device 103b reproduces content based on the PID information requested to the content reception device 105b.

  The processing in content transmission apparatus 101 and network relay apparatus 102 is the same as the process in each step of content transmission apparatus 101 and network relay apparatus 102 shown in FIG. 4 of the first embodiment. The illustration is omitted and the description thereof is omitted.

  When the power is turned on in content reproduction device 103b (YES in S611), video stream transmission request unit 112 transmits a JOIN request to a multicast address for a predetermined channel to be reproduced first to network relay device 102 (S613). ).

  Next, the PID information request unit 92 generates a PID request command 451 for requesting the PID of the TS packet storing video, audio, PCR, etc. in the channel to the content receiving device 105b, and receives the content. The data is transmitted to the device 105b (S631).

  Then, the PID information receiving unit 111b receives the PID response response 452 transmitted from the content receiving apparatus 105b in response to the PID request command 451 (S632 (packet identification information receiving step)). Then, the PID of the TS packet storing the video, audio, PCR, etc. described in the acquired PID response response 452 is stored in the PID information storage unit 122.

  Next, when the video stream receiving unit 113 receives the MPEG2-TS stream corresponding to the JOIN request (S614), the reproduction processing unit 114 stores the video, audio, and video of the channel stored in the PID information storage unit 122. The PID of the TS packet storing the PCR or the like is set to the decoding unit 115, and the received video stream is input to the decoding unit 115 (S615 (decoding processing step)). The decoded video and audio are reproduced on the display unit 140.

  Then, the content reproduction apparatus 103b waits until a channel switching instruction is received from the user (NO in S616). Then, when there is a channel switching instruction (YES in S616), the video stream transmission stop request unit 119 sends a LEAVE request to stop the currently received channel stream (S617).

  Then, the video stream transmission request unit 112b transmits the JOIN request again to the newly designated channel (S613), and performs the above processes to reproduce the video and audio (S631, S632, S614, S615). ).

  In the above description, a JOIN request is transmitted (S613), then a PID request command is transmitted (S631), a PID response response is received (S632), and then a video stream is received. Although the form of performing (S614) was demonstrated, it is not limited to this order. For example, the PID request command may be transmitted prior to the transmission of the JOIN request, and the video stream may be received before the PID response response is received.

(Processing flow in content receiving device)
Next, a procedure in which the content receiving apparatus 105b transmits a PID response response 452 in response to the PID request command 451 transmitted from the content reproduction apparatus 103b will be described with reference to FIG. FIG. 12 is a flowchart showing a flow in which the content receiving apparatus 105b transmits a PID response response 452 in response to the PID request command 451 transmitted from the content reproduction apparatus 103b.

  The processing in content transmission apparatus 101 and network relay apparatus 102 is the same as the process in each step of content transmission apparatus 101 and network relay apparatus 102 shown in FIG. 4 of the first embodiment. The illustration is omitted and the description thereof is omitted. Further, in each step in the content receiving apparatus 105b, the same reference numerals are added to the steps for performing the same processing as the steps shown in FIG. 4 of the first embodiment, and the description thereof is omitted. .

  First, the content receiving apparatus 105a performs processing for acquiring all PIDs of receivable channel contents (S414 to S424). When the PID request command 451 is transmitted from the content playback apparatus 103b after the acquisition of PIDs for all channels is completed (NO in S414), the PID request receiving unit 91 receives the PID request command 451 ( YES in S431).

  Then, the PID information transmission unit 17b acquires the PID specified by the received PID request command 451 from the PID information storage unit 22, and generates a PID response response 452. Then, the generated PID response response 452 is transmitted to the content reproduction apparatus 103b (S432).

  On the other hand, when PID request receiving unit 91 does not receive PID request command 451 (NO in S431), PID response response 452 is not transmitted.

  Thereafter, content receiving apparatus 105b waits until a predetermined time elapses (NO in S433), and when the predetermined time elapses (YES in S433), deletes all PIDs stored in PID information storage unit 22, Again, a process of acquiring all PIDs of receivable channel contents is performed (S414 to S424).

(PID request command and PID response response)
Next, a specific description of the PID request command 451 will be described with reference to FIG. FIG. 13A is a diagram illustrating a specific description example of the PID request command 451.

  As shown in FIG. 13A, the PID request command 451 is an HTTP GET request. Then, it is specified as the URL “http: //reciver1/pid_channel1.txt” of the content receiving apparatus 105b. This requests acquisition of the PID relating to “Channel 1”.

  Next, a specific description of the PID response response 452 will be described with reference to FIG. FIG. 13B is a diagram illustrating a specific description example of the PID response response 452.

  As shown in FIG. 13B, the PID response response 452 is an HTTP OK response. The PID included in “Channel 1” is PMT_PID (value is 50), “Audio_PID” (value is 100), “Video_PID” (value is 101), and “PCR_PID” (value is 101). Yes.

  In the above description, the content reproduction apparatus 103b has exchanged the PID request command 451 and the PID response response 452 with respect to one content reception apparatus 105b. However, the present invention is not limited to this. For example, the PID request command 451 may be transmitted to a plurality of content receiving devices at the same time, or when the PID response response 452 cannot be received from the content receiving device to which the PID request command 451 has been transmitted. A separate PID request command 451 may be transmitted to another content receiving apparatus.

  Further, in the above description, the PID request command 451 is transmitted to the content receiving device 105b in response to a channel switching instruction from the user. However, the present invention is not limited to this. For example, the PID information may be acquired in advance by transmitting a PID request command 451 to the content receiving apparatus 105b and receiving the PID response response 452 asynchronously with the channel switching instruction from the user. When switching channels, the previously acquired PID information may be used.

  As described above, the content reproduction apparatus 103b according to the present embodiment transmits the PID request command 451 to request only the PID necessary for content reproduction from the content reception apparatus 105b. In response to the PID request command 451 transmitted from the content reproduction device 103b, the content receiving device 105b transmits a PID response response 452 including the designated PID. Then, the content playback apparatus 103b receives the PID response response 452, performs decoding processing based on the PID of the TS packet storing video, audio, PCR, etc. described in the response, and plays back the content. To do.

  As a result, the content reproduction apparatus 103b can acquire the PID in advance, and can reproduce the content immediately after receiving the video stream. Therefore, it is possible to reduce the time required from when the channel switching instruction is received from the user until the content after switching is played back.

  In addition, the content receiving device 105b in the present embodiment transmits the requested PID only when there is a request from the content reproduction device 103b. Therefore, since the process of acquiring unnecessary PID is reduced, it is possible to reduce the processing load on the content receiving apparatus 105b.

[Embodiment 3]
In the second embodiment, the mode has been described in which the content receiving device 105b acquires PID information for all channels in advance regardless of whether there is a request from the content reproduction device 103b. However, the timing for acquiring the PID information for all channels is not limited to the above.

  Therefore, in the present embodiment, a mode in which the content receiving apparatus acquires PID information for all channels in response to a request from the content reproduction apparatus will be described.

  An embodiment of the present invention will be described below with reference to FIGS. For convenience of explanation, members having the same functions as those shown in the first or second embodiment are denoted by the same reference numerals and description thereof is omitted.

(Overall configuration of content playback system)
The content reproduction system 100c according to the present embodiment will be described with reference to FIG. FIG. 14 is a block diagram illustrating a configuration of a content reproduction system 100c including the content reproduction device 103c and the content reception device 105c, the content transmission device 101, and the network relay device 102 according to the present embodiment.

  The content playback device 103c is a client that plays back video content distributed via the communication network 1110 and the communication network 1120, similarly to the content playback device 103b.

  Similar to the content receiver 105b, the content receiver 105c is a client that receives video content distributed via the communication network 1110 and the communication network 1120, but does not have a playback function.

(Configuration of content receiving device)
Next, the configuration of the content receiving apparatus 105c according to the present embodiment will be described with reference to FIG. FIG. 15 is a block diagram showing a configuration of content receiving apparatus 105c according to the present embodiment.

  As shown in FIG. 15, the content receiving device 105c includes substantially the same members as the content receiving device 105b of the second embodiment, but includes a communication unit 30c instead of the communication unit 30b. Further, an input / output control unit 70c is provided instead of the input / output control unit 70b. Further, a control unit 10c is provided instead of the control unit 10b.

  The communication unit 30c includes substantially the same members as the communication unit 30b of the second embodiment, but includes a reception unit 31c instead of the reception unit 31b.

  In addition to receiving the video stream transmitted from the network relay device 102 and the PID request command 451 transmitted from the content reproduction device 103b, the reception unit 31c receives all the channels transmitted from the content reproduction device 103c. A PID acquisition instruction 454 (described later) for instructing acquisition of PID information is received. The video stream, PID request command 451, and PID acquisition instruction 454 received by the reception unit 31c are sent to the reception control unit 71c.

  The input / output control unit 70c includes substantially the same members as the input / output control unit 70b of the second embodiment, but includes a reception control unit 71c instead of the reception control unit 71b.

  The reception control unit 71c controls the reception unit 31c, transmits the received video stream to the video stream reception unit 12, and receives the received PID request command 451 in addition to transmitting to the PID request reception unit 91. A PID acquisition instruction 454 is transmitted to a PID acquisition instruction receiving unit 93 described later.

  The control unit 10c includes substantially the same members as the control unit 10b of the second embodiment, but newly includes a PID acquisition instruction reception unit 93. Further, instead of the PID information inspection unit 16, a PID information inspection unit 16c is provided.

  The PID acquisition instruction receiving unit 93 receives the PID acquisition instruction 454 transmitted from the content reproduction device 103c via the receiving unit 31c. Then, the PID information inspecting unit 16c is notified that the PID acquisition instruction 454 has been received.

  In response to the notification from the PID acquisition instruction receiving unit 93, the PID information inspection unit 16c inspects whether PID information has been acquired for all channels. If PID information has not been acquired for all channels, the PID information inspection unit 16c transmits a message to that effect to the video stream transmission request unit 11. On the other hand, when PID information is acquired for all channels, the PID information inspection unit 16c transmits a message to that effect to the PID information transmission unit 17b.

(Configuration of content playback device)
Next, the configuration of the content reproduction apparatus 103c according to the present embodiment will be described with reference to FIG. FIG. 16 is a block diagram showing a configuration of the content reproduction apparatus 103c according to the present embodiment.

  As shown in FIG. 16, the content playback apparatus 103c includes substantially the same members as the content playback apparatus 103b of the second embodiment, but includes a communication unit 130c instead of the communication unit 130b. Further, an input / output control unit 170c is provided instead of the input / output control unit 170b. Further, a control unit 110c is provided instead of the control unit 110b.

  The communication unit 130c includes substantially the same members as the communication unit 130b of the second embodiment, but includes a transmission unit 132c instead of the transmission unit 132b.

  The transmission unit 132c transmits an IGMP JOIN request and a LEAVE request to the network relay device 102, and transmits a PID request command 451 to the content reception device 105c, and in addition to the content reception device 105c. Then, a PID acquisition instruction 454 is transmitted.

  The input / output control unit 170c includes substantially the same members as the input / output control unit 170b of the second embodiment, but includes a transmission control unit 172c instead of the transmission control unit 172b.

  The transmission control unit 172c controls the transmission unit 132c to receive a JOIN request received from the video stream transmission request unit 112b, a LEAVE request received from the video stream transmission stop request unit 119, and a PID request command 451 received from the PID information request unit 92. In addition, a PID acquisition instruction 454 received from the PID acquisition instruction unit 94 is transmitted to the transmission unit 132c.

  The control unit 110c includes substantially the same members as the control unit 110b of the second embodiment, but newly includes a PID acquisition instruction unit 94.

  The PID acquisition instruction unit 94 generates a PID acquisition instruction 454 that instructs the content reception device 105c to acquire PID information for all channels, and transmits the PID acquisition instruction 454 to the transmission control unit 172c. The timing for transmitting the PID acquisition instruction 454 is, for example, immediately after the content receiver 105c is turned on.

(Processing flow until content playback)
Next, with reference to FIG. 17 and FIG. 18, the content reproduction device 103 c transmits a PID acquisition instruction 454 to the content reception device 105 c and then reproduces the content transmitted from the network relay device 102. explain.

(Processing flow in content playback device)
First, a procedure for reproducing content after the content reproduction device 103c transmits a PID acquisition instruction 454 to the content reception device 105c will be described with reference to FIG. FIG. 17 is a flowchart illustrating a flow in which the content reproduction device 103c reproduces content after transmitting a PID acquisition instruction 454 to the content reception device 105c.

  The processing in content transmission apparatus 101 and network relay apparatus 102 is the same as the process in each step of content transmission apparatus 101 and network relay apparatus 102 shown in FIG. 4 of the first embodiment. The illustration is omitted and the description thereof is omitted. Further, in each step in content receiving apparatus 105c, the same reference numerals are given to the steps for performing the same processes as those shown in FIG. 11 of the second embodiment, and the description thereof is omitted. .

  When the power of content reproduction device 103c is turned on (YES in S611), PID acquisition instruction unit 94 transmits PID acquisition instruction 454 to content reception device 105c (S633).

  Next, the video stream transmission request unit 112b transmits a JOIN request to the multicast address for the predetermined channel to be reproduced first to the network relay apparatus 102 (S634). Then, the video stream receiving unit 113 receives the video stream from the network relay device 102 (S635).

  Next, at this time, since a predetermined time has not elapsed since the transmission of the PID acquisition instruction 454 in step S633, the content reception device 105c performs the PID for all channels based on the PID acquisition instruction 454 transmitted above. There is a high possibility that the information is being acquired. Therefore, instead of transmitting the PID request command 451 to the content receiving device 105c, the reproduction processing unit 114 analyzes the video stream received from the video stream receiving unit 113, acquires the PAT and PMD, and further receives the video from the PMT. The PID of the TS packet including voice, PCR, etc. is acquired (S636, S637). Then, the obtained PID is set in the decoding unit 115, and the video stream received from the video stream receiving unit 113 is transmitted to the decoding unit 115, and a reproduction instruction is given (S638).

  Thereafter, content reproduction apparatus 103c stands by until a channel switching instruction is received from the user (NO in S639). When there is a channel switching instruction (YES in S639), the video stream transmission stop request unit 119 transmits a LEAVE request (S640), and stops the stream of the currently received channel.

  Next, if the predetermined time has not elapsed since the transmission of the PID acquisition instruction 454 in step S633 (NO in S641), the video stream transmission request unit 112 again performs JOIN for the newly designated channel. The request is transmitted (S634), the video stream is analyzed, and a reproduction instruction is given to the decoding unit 115 (S635 to S638).

  On the other hand, when a predetermined time has elapsed since the transmission of the PID acquisition instruction 454 in step S633 (YES in S641), the content reception device 105c determines that all channels are based on the PID acquisition instruction 454 transmitted above. There is a high possibility that the PID information has been acquired. In this case, the content playback apparatus 103c performs processing for transmitting the PID request command 451 to the content receiving apparatus 105c and receiving the PID response response 452 without analyzing the video stream. Since the subsequent processing (S613 to S617) is the same as the steps described in the second embodiment, the description thereof is omitted.

(Processing flow in content receiving device)
Next, a procedure in which the content receiving apparatus 105c acquires PIDs for all channels based on the PID acquisition instruction transmitted from the content reproduction apparatus 103c will be described with reference to FIG. FIG. 18 is a flowchart showing a flow in which the content receiving apparatus 105c acquires PIDs for all channels based on the PID acquisition instruction 454 transmitted from the content reproduction apparatus 103c.

  The processing in content transmission apparatus 101 and network relay apparatus 102 is the same as the process in each step of content transmission apparatus 101 and network relay apparatus 102 shown in FIG. 4 of the first embodiment. The illustration is omitted and the description thereof is omitted. In addition, in each step in the content receiving device 105c, steps that perform the same processing as the steps shown in FIG. 12 of the second embodiment are denoted by the same reference numerals for the sake of convenience of description, and description thereof is omitted. .

  After the content receiving device 105c is turned on (YES in S413), if the PID acquisition instruction 454 transmitted by the content reproduction device 103c is issued (YES in S433), the content receiving device 105c is the same as that of the second embodiment. As described with reference to FIG. 12, processing for acquiring all PIDs of receivable channel contents is performed (S414 to S421).

  Then, after acquisition of all PIDs of receivable channel contents is completed (NO in S414), or when the PID acquisition instruction 454 transmitted by the content reproduction apparatus 103c is not issued (NO in S433), the content reproduction apparatus A PID response response 452 is transmitted from 103b in response to the PID request command 451. Since the subsequent processing (S431 to S432) is the same as the steps described in the second embodiment, the description thereof is omitted.

  In the above description, a mode has been described in which, when transmitting the PID acquisition instruction 454 to the content receiving apparatus 105c, it is not specified which channel PID is to be acquired. However, the present invention is not limited to this. For example, the PID acquisition instruction 454 may include designation of a channel, and the content receiving apparatus 105c may obtain only the PID related to the designated channel.

  As described above, the content reproduction device 103c according to the present embodiment first instructs the content reception device 105c to instruct the content reception device 105c to acquire PID information for all channels. 454 is transmitted. In response to the instruction from the content reproduction device 103c, the content reception device 105c acquires PID information for all channels.

  Thereafter, the content playback device 103c transmits a PID request command 451 to request only the PID necessary for content playback to the content reception device 105c. Then, the content receiving apparatus 105c transmits the PID designated by the PID request command 451 included in the PID response response 452 among the PIDs acquired in response to the PID acquisition instruction 454. Then, the content playback device 103c receives the PID response response 452, performs playback based on the PID of the TS packet including video, audio, PCR, etc. described in the response, and plays back the content. .

  In this way, since the trigger for acquiring the PID information for all the channels is given from the content reproduction apparatus 103c to the content reception apparatus 105c, the latest PID for all the channels immediately before the content reproduction apparatus 103c reproduces the content. Information can be acquired by the content receiving apparatus 105c. Therefore, for example, a case where the content reproduction device 103c acquires information related to the television program guide from the outside via the communication network 1120, but the content reception device 105c does not acquire information related to the television program guide is taken as an example. explain. In this case, when the PID of the TS packet storing video or audio is switched at the timing of switching the content to be played back by the content playback device 103c, the content playback device 103c issues a PID acquisition instruction 454 to the content reception device 105c. By transmitting, the content receiving apparatus 105c can always hold the latest PID information.

[Embodiment 4]
In the first to third embodiments, a description will be given of a mode in which a content reproduction device reproduces content by cooperation between a content reproduction device that is a client that reproduces video content and a content reception device that is a client that transmits PID information. did. However, the client is not limited to the above.

  Therefore, in the present embodiment, a mode in which a content reception / playback apparatus that is a client that plays back video content and transmits PID information plays back the content will be described.

  One embodiment of the present invention will be described below with reference to FIGS. For convenience of explanation, members having the same functions as those shown in the first to third embodiments are denoted by the same reference numerals, and description thereof is omitted.

(Overall configuration of content playback system)
The content reproduction system 100d according to the present embodiment will be described with reference to FIG. FIG. 19 shows a plurality of content reception / playback devices 104 according to the present embodiment, a content playback device 103a (third external device) and a content reception device 105a (second external device) according to the first embodiment, and content transmission. It is a block diagram which shows the structure of the content reproduction system 100d containing the apparatus 101 (1st external device) and the network relay apparatus 102.

  The content reception / playback apparatus 104 is a client that plays back video content distributed via the communication network 1110 and the communication network 1120 and transmits PID information to other clients. Further, the content reception / playback apparatus 104 may receive an input from a user by an input operation device such as a remote controller.

(Configuration of content reception / playback device)
Next, the configuration of the content reception / playback apparatus 104 according to the present embodiment will be described with reference to FIG. FIG. 20 is a block diagram showing a configuration of content reception / playback apparatus 104 according to the present embodiment.

  As shown in FIG. 20, the content reception / playback device 104 includes substantially the same members as the content playback device 103 a of the first embodiment, but includes a communication unit 130 d instead of the communication unit 130. Further, an input / output control unit 170d is provided instead of the input / output control unit 170. Further, a control unit 110d is provided instead of the control unit 110.

  The communication unit 130d includes substantially the same members as the communication unit 130 of the first embodiment, but includes a reception unit 131d instead of the reception unit 131. Further, a transmission unit 132d is provided instead of the transmission unit 132.

  In addition to receiving the video stream transmitted from the network relay device 102, the reception unit 131d receives the PID list 450 transmitted from another content reception / playback device or the content reception device 105a. The video stream and PID list 450 received by the reception unit 131d are sent to the reception control unit 171d.

  The transmission unit 132d transmits the PID list 450 to the other content reception / playback devices and the content playback device 103a in addition to sending the IGMP JOIN request and the LEAVE request to the network relay device 102. Yes, controlled by the transmission controller 172d.

  The input / output control unit 170d includes substantially the same members as the input / output control unit 170 of the first embodiment, but includes a reception control unit 171d instead of the reception control unit 171. Further, a transmission control unit 172d is provided instead of the transmission control unit 172.

  The reception control unit 171d controls the reception unit 131d to transmit the received video stream to the video stream reception unit 113, and also transmits the received PID list 450 to the PID information reception unit 111d described later.

  The transmission control unit 172d controls the transmission unit 132d, and in addition to the JOIN request received from the video stream transmission request unit 112 and the LEAVE request received from the video stream transmission stop request unit 119, the PID list received from the PID information transmission unit 17d 450 is transmitted to the transmission unit 132d.

  The control unit 110d includes substantially the same members as the control unit 110 of the first embodiment, but includes a PID information reception unit 111d instead of the PID information reception unit 111. Further, a video stream receiving unit 113d is provided instead of the video stream receiving unit 113. Further, a playback processing unit 114d is provided instead of the playback processing unit 114. Further, a program identification information acquisition unit 13d, a PID information acquisition unit 14d, and a PID information transmission unit 17d are newly provided.

  The PID information receiving unit 111d receives the PID list 450 transmitted from another content receiving / playback apparatus and the content receiving apparatus 105a. Then, the PID described in the received PID list 450 is stored in the PID information storage unit 122. These PIDs are used as PIDs set in the decoding unit 115.

  The video stream reception unit 113d receives the video stream transmitted from the network relay apparatus 102 via the reception unit 131d, and transmits the received video stream to the reproduction processing unit 114d. At the same time, the received video stream is transmitted to the program identification information acquisition unit 13d.

  The program identification information acquisition unit 13d analyzes the video stream from the video stream reception unit 113d, and acquires PAT and PMT which are program identification information. Then, the acquired PMT is transmitted to the PID information acquisition unit 14d.

  The PID information acquisition unit 14d analyzes the PMT transmitted from the program identification information acquisition unit 13d, and acquires the PID of the TS packet that stores video, the PID of the TS packet that stores audio, and the PID of the TS packet that stores PCR To do. The acquired PID is stored in the PID information storage unit 122 for each channel number. Further, the acquired PID is transmitted to the PID information transmitting unit 17d in order to transmit it to another content receiving / playback apparatus or the content playback apparatus 103a. Further, in order to decode the video stream received by the video stream receiving unit 113d, the acquired PID is transmitted to the reproduction processing unit 114d.

  The PID information transmission unit 17d generates a PID list 450 based on the PID transmitted from the PID information acquisition unit 14d, and transmits the PID list 450 to the transmission control unit 172d for transmission to other content reception / playback devices and the content playback device 103a. To do.

  The reproduction processing unit 114d decodes the video stream received from the video stream reception unit 113d by using the PID transmitted from the other content reception / playback device and the content reception device 105a, which is stored in the PID information storage unit 122. If possible, the PID is set in the decoding unit 115, and the video stream received from the video stream receiving unit 113 is transmitted to the decoding unit 115 to give a reproduction instruction.

  On the other hand, if the video stream received from the video stream receiving unit 113d cannot be decoded using the PID stored in the PID information storage unit 122, the PID transmitted from the PID information acquisition unit 14d is set in the decoding unit 115. At the same time, the video stream received from the video stream receiving unit 113 is transmitted to the decoding unit 115 to instruct reproduction.

(Processing flow until content playback)
Next, a procedure in which the content reception / playback device 104 acquires PID information from another content reception / playback device or the content reception device 105a and plays back the content transmitted from the network relay device 102 will be described with reference to FIG. To do. A procedure in which the content reception / playback apparatus 104 transmits the PID acquired from the received video stream to another content reception / playback apparatus or the content playback apparatus 103a will be described. FIG. 21 is a flowchart showing a flow in which the content reception / playback apparatus 104 plays back the content and transmits the acquired PID.

  The processing in content transmission apparatus 101 and network relay apparatus 102 is the same as the process in each step of content transmission apparatus 101 and network relay apparatus 102 shown in FIG. 4 of the first embodiment. The illustration is omitted and the description thereof is omitted.

  When the content receiving / reproducing apparatus 104 is powered on (YES in S711), the video stream transmission requesting unit 112 transmits to the network relay apparatus 102 a JOIN request to a multicast address for a predetermined channel to be reproduced first (S712). ).

  When the video stream receiving unit 113d receives the MPEG2-TS stream corresponding to the JOIN request (S713), the playback processing unit 114d analyzes the video stream received from the video stream receiving unit 113d, and acquires PAT and PMD. Furthermore, the PID of a TS packet including video, audio, PCR, etc. is acquired from the PMT (S714 (program identification information acquisition step), S715 (packet identification information acquisition step)). Then, the obtained PID is set in the decoding unit 115, and the video stream received from the video stream receiving unit 113d is transmitted to the decoding unit 115 to give a reproduction instruction (S716 (decoding processing step)).

  Then, a PID list 450 is generated based on the acquired PID, and the PID list 450 is distributed to other content receiving / playback apparatuses and content playback apparatus 103a (S717 (packet identification information transmission step)). This distribution may be performed, for example, by broadcast or IP multicast, or may be transmitted by unicast to an IP address of another content reception / playback device or content playback device 103a set in advance.

  Next, it waits for reception of a PID list 450 transmitted from another content reception / playback device or content reception device 105a (S718 (packet identification information reception step)). When PID information receiving section 111d receives PID list 450 transmitted from another content receiving / playback apparatus or content receiving apparatus 105a (YES in S718), PID information included in received PID list 450 is converted to PID information. The data is stored in the storage unit 122 (S719). If there is no channel switching instruction from the user (NO in S720), the process waits for reception of a PID list 450 transmitted from another content receiving / playback apparatus or content receiving apparatus 105a (S718).

  Then, if there is a channel switching instruction from the user (YES in S720), the video stream transmission stop request unit 119 sends a LEAVE request to the network relay apparatus 102 in order to stop the currently reproduced content. Transmit (S721). Subsequently, the video stream transmission request unit 112 transmits a JOIN request to request relay of the channel designated by the user (S722).

  Then, after the video stream receiving unit 113d receives the MPEG2-TS stream corresponding to the JOIN request (S724), the PID necessary for decoding the received stream is changed to another content receiving / playback apparatus or content receiving apparatus. The reproduction processing unit 114d checks whether the information is acquired from 105a (S724).

  If the PID necessary for decoding the received stream has already been acquired from another content receiving / playback apparatus or content receiving apparatus 105a (YES in S724), the playback processing unit 114d stores the PID information storage. The PID stored in the unit 122 is set in the decoder unit 155 (S725), the channel switching process is terminated, and the reception of the PID list 450 transmitted from another content receiving / playback apparatus or the content receiving apparatus 105a is again performed. I wait.

  On the other hand, if the PID necessary for decoding the received stream has not already been acquired from another content receiving / playback apparatus or content receiving apparatus 105a (NO in S724), the playback processing section 114d is set to the video stream receiving section. The video stream received from 113d is analyzed, PAT and PMD are obtained, and further, the PID of the TS packet including video, audio, PCR, etc. is obtained from the PMT (S714, S715). Then, these obtained PIDs are set in the decoding unit 115 (S716). Then, a PID list 450 is generated based on the acquired PID, and the PID list 450 is distributed to other content receiving / playback apparatuses and content playback apparatus 103a (S717). Then, it again waits for reception of the PID list 450 transmitted from another content reception / playback device or content reception device 105a.

  In the above description, the mode for analyzing the video stream in order to obtain the PID of the TS packet including video, audio, PCR, etc. in the video stream received immediately after power-on has been described. However, the present invention is not limited to this. is not. For example, the PID information transmitted from another content receiving / playback apparatus or the content receiving apparatus 105a may be acquired while waiting for power-on or immediately after power-on, and then the decoding process may be performed using the acquired PID information. . As a result, it is possible to reduce the time required from when the power is turned on until the content is reproduced.

  As described above, the content reception / playback device 104 according to the present embodiment uses the PID of the TS packet including video, audio, PCR, and the like acquired from the received video stream as the other content reception / playback device and content playback device 103a. Send to. When switching channels, the PID acquired from another content receiving / playback apparatus or the content receiving apparatus 105a is used to perform decoding processing to play back the content.

  Thereby, the content reception / playback apparatus 104 can use the PID of the TS packet including video, audio, PCR, etc. in the video stream received by another content reception / playback apparatus or the content reception apparatus 105a for the decoding process. Therefore, even if the video stream is received for the first time by the content reception / playback apparatus 104, if the PID information corresponding to the video stream has already been acquired, the time required until the video stream is played back can be shortened. it can.

  Further, the PID information acquired by the content reception / playback device 104 is transmitted to another content reception / playback device or the content playback device 103a. Therefore, even if the video stream is received for the first time by the other content receiving / playback apparatus or the content playback apparatus 103a by performing decoding processing using the transmitted PID information by the other content receiving / playback apparatus or the content playback apparatus 103a. If the PID information corresponding to the video stream has already been transmitted, the time required until the video stream is reproduced can be shortened.

  By using the content reception device, content playback device, and content reception / playback device in each embodiment of the present invention, it is possible to obtain the PID of a TS packet that stores video, audio, PCR, etc. without analyzing the video stream. Therefore, it is possible to reduce the time required to reproduce the received content without depending on the content distribution service.

(Additional notes)
In each embodiment of the present invention, when a content receiving device transmits an IGMP JOIN request, if the network relay device has already relayed to another content playback device, the relay processing is not affected. A JOIN request may be transmitted under certain conditions. For example, in a network environment where priority can be given to each video stream, the priority of the video stream relayed to the content receiving device is set lower than the priority of the video stream relayed to the content playback device, You may give priority to the relay process performed with respect to a content reproduction apparatus.

  In each embodiment of the present invention, a network capable of measuring a surplus bandwidth that can be transmitted to the network may be used. For example, the network configuration may be such that the video stream is relayed to the content receiving device only when the bandwidth necessary for transmitting the video stream to be relayed to the content receiving device is smaller than the surplus bandwidth.

  In each embodiment of the present invention, a network environment having a QoS (Quality of Service) function that can secure a transmission band may be used. For example, a necessary transmission band is secured for a video stream relayed to a content reproduction apparatus, while a transmission band is not secured or a smaller band is secured for a video stream relayed to a content receiving apparatus. Such a network configuration may be used.

  In each embodiment of the present invention, a description will be given of a mode in which the PID transmitted / received between the content reception device, the content reproduction device, and the content reception / reproduction device is the PID of a TS packet including video, audio, and PCR. However, the present invention is not limited to this. For example, a PID such as an ECM or an EMM (Entitlement Management Message) used when decrypting encrypted video content may be included.

  In addition, the video content received by the content receiving devices 105a, 105b, and 105c, the content playback devices 103a, 103b, and 103c, and the content reception / playback device 104 according to the present invention is video data, audio data, or a combination thereof. In addition, it is not limited to a specific format.

  In addition to the above, the embodiment can be expressed as follows.

[1] A content receiving apparatus according to the present invention receives multiplexed data by assigning different identifiers to at least one of video and audio and program designation information transmitted via a communication network. A reception device in a system including a reception device and a reproduction device capable of reproducing the data, wherein the transmission request means requests the multiplexed data;
Receiving means for receiving the multiplexed data, means for obtaining program identification information from the multiplexed data, and identification for obtaining video and audio identification information of one or more programs from the program identification information Information acquisition means and identification information transmission means for transmitting the video and audio identification information to the playback apparatus may be included.

  [2] The content receiving device according to the present invention further includes request receiving means for receiving a transmission request for identification information from the reproduction device, and the reproduction information is transmitted by the identification information transmitting means in response to the transmission request. The identification information may be transmitted to the device.

  [3] The content receiving apparatus according to the present invention further includes an acquisition receiving unit that receives an acquisition request for identification information from the playback device, and is multiplexed by the transmission request unit in accordance with the acquisition receiving unit. It is also possible to request transmission of data.

  [4] Further, in the content receiving device according to the present invention, the identification information transmitting means may transmit identification information to a plurality of reproducing devices at the same time.

  [5] Further, the content receiving apparatus according to the present invention is configured to provide data multiplexed by assigning different identifiers to at least one of video and audio and program designation information transmitted via a communication network. MPEG2-TS (Moving Picture Experts Group 2-Transport Stream) data, the program designation information includes PAT (Program Association Table) and PMT (Program Mapped Table), and the video and audio identification information is the video and audio PID ( Program ID).

  [6] The content reproduction apparatus according to the present invention receives multiplexed data by giving different identifiers to at least one of video and audio and program designation information transmitted via a communication network. A playback device in a system comprising a receiving device and a playback device capable of playing back the data, wherein the receiving device receives data multiplexed in the previous period, and obtains program identification information from the multiplexed data. Obtaining video and audio identification information of one or more programs from the program identification information, transmitting the video and audio identification information to a playback device, and the playback device being transmitted from the reception device The video and audio identification information may be received and used when switching programs.

  [7] Furthermore, the content reproduction apparatus according to the present invention may include identification information requesting means for requesting the reception apparatus to transmit the identification information.

  [8] Furthermore, in the content reproduction apparatus according to the present invention, the identification information requesting means may be transmitted simultaneously to a plurality of receiving apparatuses.

  [9] Furthermore, the content reproduction apparatus according to the present invention, the data multiplexed by assigning different identifiers to at least one of video and audio and program designation information transmitted via a communication network, MPEG2-TS (Moving Picture Experts Group 2-Transport Stream) data, program designation information includes PAT (Program Association Table), PMT (Program Mapped Table), and the video and audio identification information is the video and audio PID ( Program ID).

  [10] Furthermore, the content receiving device according to the present invention may have the function of the playback device.

  [11] The content receiving method according to the present invention receives multiplexed data by assigning different identifiers to at least one of video and audio and program designation information transmitted via a communication network. A reception method of a reception apparatus in a system including a reception apparatus and a reproduction apparatus capable of reproducing the data, the transmission request process for requesting the multiplexed data from a transmission source, and the data multiplexed in the previous period Receiving processing for receiving program identification information from the multiplexed data, identification information acquisition processing for acquiring video and audio identification information of one or more programs from the program identification information, and It may include identification information transmission processing for transmitting video and audio identification information to the playback apparatus.

  [12] The content playback method according to the present invention receives multiplexed data by assigning different identifiers for at least one of video and audio and program designation information transmitted via a communication network. A playback device playback method in a system comprising a receiving device and a playback device capable of playing back the data, wherein the receiving device receives data multiplexed in the previous period, and programs from the multiplexed data Obtaining identification information, obtaining video and audio identification information of one or more programs from the program identification information, transmitting the video and audio identification information to a playback device, and the playback method from the receiving device The video and audio identification information sent out may be received, and processing used when switching programs may be performed.

[13] A reception program according to the present invention receives a multiplexed data by giving different identifiers to at least one of video and audio and program designation information transmitted via a communication network. A receiving program for controlling a receiving device in a system composed of a device and a reproducing device capable of reproducing the data, wherein a transmission request step for requesting the multiplexed data from a transmission source, A receiving step for receiving data;
Obtaining program identification information from the multiplexed data; identification information obtaining step for obtaining video and audio identification information for one or more programs from the program identification information; and video and audio identification information. An identification information transmission step to be transmitted to the playback device may be executed.

  [14] A reproduction program according to the present invention receives data multiplexed via at least one of video and audio and program designation information assigned with different identifiers transmitted via a communication network. A playback program for controlling a playback device in a system comprising a device and a playback device capable of playing back the data, wherein the receiving device receives data multiplexed in the previous period and programs from the multiplexed data Obtaining identification information, obtaining video and audio identification information of one or more programs from the program identification information, transmitting the video and audio identification information to a playback device, and the playback program from the reception device The video and audio identification information sent out may be received, and a step used when switching programs may be executed.

  [15] A system according to the present invention receives a multiplexed data by giving different identifiers to at least one of video and audio and program designation information transmitted via a communication network And a receiving apparatus capable of reproducing the data, wherein the receiving apparatus receives the multiplexed data from a transmission request means for requesting the multiplexed data from a transmission source. Receiving means; means for obtaining program identification information from the multiplexed data; identification information obtaining means for obtaining video and audio identification information of one or more programs from the program identification information; and the video and audio Identification information transmitting means for transmitting the identification information of the video and audio to the playback device, wherein the playback device receives the video and audio identification information sent from the reception device, and switches between programs. It may have a means be utilized in.

  Finally, the control units 10, 10b, 10c, 110, 110b, 110c, and 110d may be realized by software using a CPU (Central Processing Unit) or may be configured by hardware logic. When implemented by software, the content receiving devices 105a, 105b, and 105c, the content reproducing devices 103a, 103b, and 103c, and the content receiving and reproducing device 104 store a CPU that executes a command of a control program that realizes each function, and the above program And a storage device (recording medium) such as a memory for storing the program and various data. The object of the present invention is to provide program codes (execution format programs) of control programs for the content receiving devices 105a, 105b, and 105c, the content reproducing devices 103a, 103b, and 103c, and the content receiving and reproducing device 104, which are software that implements the functions described above. , An intermediate code program, a source program) recorded on a computer readable recording medium is supplied to the content receiving devices 105a, 105b, and 105c, the content reproducing devices 103a, 103b, and 103c, and the content receiving and reproducing device 104, and the content receiving device 105a, 105b, 105c, content playback devices 103a, 103b, 103c, and a computer (or CPU or MPU (micro processing unit)) in the content reception playback device 104 record on a recording medium. May read and execute the program code stored, it is achievable.

  Examples of the recording medium include tapes such as magnetic tapes and cassette tapes, magnetic disks such as floppy (registered trademark) disks / hard disks, and disks including optical disks such as CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

  The content receiving devices 105a, 105b, and 105c, the content reproducing devices 103a, 103b, and 103c, and the content receiving and reproducing device 104 may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication. A net or the like is available. Also, the transmission medium constituting the communication network is not particularly limited, and for example, an infrared ray such as IrDA, Bluetooth (Bluetooth) (IEEE1394 cable, USB cable, power line carrier, cable TV line, telephone line, ADSL line, etc.) (Registered trademark), 802.11 wireless, HDR, mobile phone network, satellite line, terrestrial digital network, etc. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be applied to a content receiving apparatus or a content reproducing apparatus that can receive and reproduce multiplexed video and audio transmitted via a communication network, and in particular, MPEG2-TS. It can be suitably used for a content receiving apparatus or a content reproducing apparatus that can receive and reproduce a video stream distributed using.

It is a block diagram which shows the principal part structure of the content receiver in the content reproduction system shown in FIG. It is a block diagram which shows the principal part structure of the content reproduction system containing the content reproduction apparatus and content reception apparatus which concern on embodiment of this invention. It is a block diagram which shows the principal part structure of the content reproduction apparatus in the content reproduction system shown in FIG. 4 is a flowchart illustrating a flow in which the content receiving apparatus illustrated in FIG. 1 acquires PIDs for all channels from the content transmitting apparatus in advance and transmits the PIDs to the content reproduction apparatus illustrated in FIG. 3. 4 is a flowchart showing a flow in which the content reproduction device shown in FIG. 3 reproduces content based on the PID list obtained from the content reception device shown in FIG. 1. FIG. 6A is a diagram schematically showing the data structure of the PID list according to the embodiment of the present invention. FIG. 6B is a diagram illustrating a specific description example of the PID list illustrated in FIG. FIG. 7A is a diagram schematically showing a description example of an HTTP GET request when transmitting a PID list according to the embodiment of the present invention. FIG. 7B is a diagram schematically illustrating a description example of a response to the request illustrated in FIG. It is a block diagram which shows the principal part structure of the content reproduction system containing the other content reproduction apparatus and other content reception apparatus which concern on embodiment of this invention. It is a block diagram which shows the principal part structure of the content receiver in the content reproduction system shown in FIG. It is a block diagram which shows the principal part structure of the content reproduction apparatus in the content reproduction system shown in FIG. 11 is a flowchart showing a flow of reproducing content based on PID information requested by the content reproduction device shown in FIG. 10 to the content reception device shown in FIG. 9. FIG. 11 is a flowchart illustrating a flow in which the content receiving apparatus illustrated in FIG. 9 transmits a PID response response to the PID request command transmitted from the content reproduction apparatus illustrated in FIG. 10. FIG. 13A is a diagram showing a specific description example of the PID request command according to the embodiment of the present invention. FIG. 13B is a diagram showing a specific description example of the PID response response according to the embodiment of the present invention. It is a block diagram which shows the principal part structure of the content reproduction system containing the other content reproduction apparatus and other content reception apparatus which concern on embodiment of this invention. It is a block diagram which shows the principal part structure of the content receiver in the content reproduction system shown in FIG. It is a block diagram which shows the principal part structure of the content reproduction apparatus in the content reproduction system shown in FIG. 16 is a flowchart showing a flow of reproducing content after the content reproduction device shown in FIG. 16 transmits a PID acquisition instruction to the content reception device shown in FIG. 15. 17 is a flowchart illustrating a flow in which the content receiving apparatus illustrated in FIG. 15 acquires PIDs for all channels based on a PID acquisition instruction transmitted from the content reproduction apparatus illustrated in FIG. It is a block diagram which shows the structure of the content reception system which contains the content receiving / reproducing apparatus which concerns on this embodiment, the content reproducing apparatus shown in FIG. 3, and the content receiving apparatus shown in FIG. It is a block diagram which shows the principal part structure of the content receiving / reproducing apparatus in the content reproduction system shown in FIG. FIG. 21 is a flowchart illustrating a flow in which the content reception / playback apparatus illustrated in FIG. 20 plays back content and transmits the acquired PID. It is a figure which shows the data structure of a transport stream packet typically. FIG. 23A is a diagram schematically showing video data and audio data to be multiplexed into a transport stream. FIG. 23B is a diagram schematically illustrating a state in which the video data and audio data illustrated in FIG. 23A are divided into transport stream packets. FIG. 23 (c) is a diagram schematically showing a state in which a header part and an adaptation part are added to the data after the division shown in FIG. 23 (b). FIG. 23 (d) is a diagram schematically showing a state where the packets to which the header part and the adaptation part shown in FIG. 23 (c) are added are collected into one transport stream. It is a flowchart which shows the flow of the process which distributes a content from a content transmission apparatus to a receiving device via a network relay apparatus by an IP multicast technique, and displays a content, and the process which switches a content.

Explanation of symbols

11 Video stream transmission request section (stream transmission request means)
12 Video stream receiver (stream receiving means)
13 Program identification information acquisition unit (program identification information acquisition means)
13d Program identification information acquisition unit (program identification information acquisition means)
14 PID information acquisition unit (packet identification information acquisition means)
14d PID information acquisition unit (packet identification information acquisition means)
15 Video stream transmission stop request unit 16 PID information inspection unit 16c PID information inspection unit 17 PID information transmission unit (packet identification information transmission means)
17b PID information transmitter (packet identification information transmitter)
17d PID information transmitter (packet identification information transmitter)
22 PID information storage unit 91 PID request reception unit 92 PID information request unit (packet identification information transmission request means)
93 PID acquisition instruction receiving unit 94 PID acquisition instruction unit 100a Content reproduction system 100b Content reproduction system 100c Content reproduction system 100d Content reproduction system 101 Content transmission apparatus (first external apparatus)
103a Content playback device (third external device)
103b Content playback device 103c Content playback device 104 Content reception / playback device (second external device, third external device)
105a Content receiving device (second external device)
105b Content receiver 105c Content receiver 111 PID information receiver (packet identification information receiver)
111b PID information receiving unit (packet identification information receiving means)
111d PID information receiving unit (packet identification information receiving means)
114 reproduction processing unit 114d reproduction processing unit 115 decoding unit (decoding processing means)
122 PID information storage unit 450 PID list (packet identification information)
451 PID request command 452 PID response response (packet identification information)
454 PID acquisition instruction

Claims (18)

Dividing at least one of video and audio included in one or more contents into a plurality of packets, and adding packet identification information that allows each packet to be identified to a packet including program identification information that identifies the packet and the content, One or a plurality of content playback apparatuses and a communication network that receive each stream from an external device that multiplexes each packet with the packet identification information added and transmits the multiplexed packet and transmits the content included in the received stream. A content receiving device that is connected via the external device and receives the stream from the external device,
Stream transmission request means for requesting the external device to transmit the stream;
Stream receiving means for receiving the requested stream;
Program identification information acquisition means for acquiring the program identification information from the received stream;
Packet identification information acquisition means for acquiring packet identification information of packets included in the received stream from the acquired program identification information;
A content receiving apparatus comprising: packet identification information transmitting means for transmitting the acquired packet identification information to one or a plurality of the content reproduction apparatuses.   The packet identification information transmitting means transmits, in response to a request from the content reproduction device, packet identification information corresponding to the request among the acquired packet identification information to the content reproduction device that has made the request. The content receiving apparatus according to claim 1.   3. The content receiving apparatus according to claim 1, wherein the stream transmission requesting unit requests the external apparatus to transmit the stream in response to an instruction from the content reproduction apparatus.   The stream is MPEG2-TS (Moving Picture Experts Group 2-Transport Stream), the program identification information includes PAT (Program Association Table) and PMT (Program Mapped Table), and the packet identification information is PID (Packet Identifier). The content receiving device according to claim 1, wherein the content receiving device is provided. Dividing at least one of video and audio included in one or more contents into a plurality of packets, and adding packet identification information that allows each packet to be identified to a packet including program identification information that identifies the packet and the content, Each packet to which packet identification information is added is multiplexed and transmitted from an external device that transmits it as one stream, the program identification information is acquired from the received stream, and the program identification information is acquired from the acquired program identification information. The content included in the received stream is obtained by acquiring packet identification information for identifying a packet included in the stream, connected to a content receiving apparatus that transmits the acquired packet identification information via a communication network, receiving the stream, and A content playback device for playing
Packet identification information receiving means for receiving the packet identification information transmitted from the content receiving device;
A content reproduction apparatus comprising: decoding processing means for decoding the received stream using the received packet identification information.   6. The content reproduction apparatus according to claim 5, further comprising packet identification information transmission requesting means for requesting transmission of the packet identification information from one or more of the content reception apparatuses. Program identification information acquisition means for acquiring program identification information for identifying each content from the received stream;
Packet identification information acquisition means for acquiring packet identification information of packets included in the received stream from the acquired program identification information;
If the packet identification information received by the packet identification information receiving means cannot be used when the decoding processing means decodes the received stream, the packet identification information obtained by the packet identification information obtaining means should be used. The content reproduction apparatus according to claim 5 or 6.   The stream is MPEG2-TS (Moving Picture Experts Group 2-Transport Stream), the program identification information includes PAT (Program Association Table) and PMT (Program Mapped Table), and the packet identification information is PID (Packet Identifier). The content reproduction apparatus according to claim 5, wherein the content reproduction apparatus is provided. Dividing at least one of video and audio included in one or more contents into a plurality of packets, and adding packet identification information that allows each packet to be identified to a packet including program identification information that identifies the packet and the content, Multiplex each packet with packet identification information added, receive the stream from the first external device that transmits as one stream, acquire program identification information identifying each content from the received stream, and acquire A third external device that acquires packet identification information for identifying a packet included in the stream from the program identification information, and transmits the acquired packet identification information to one or a plurality of second external devices that reproduce the content; and,
Receiving the stream from the first external device, receiving packet identification information transmitted from the third external device, and decoding the received stream using the received packet identification information; A content reception / playback apparatus that is connected to at least one of the second external devices that plays back the content included in the received stream via a communication network, receives the stream from the first external device, and plays back the stream. And
Program identification information acquisition means for acquiring the program identification information from the received stream;
Packet identification information acquisition means for acquiring packet identification information of packets included in the received stream from the acquired program identification information;
Packet identification information transmitting means for transmitting the acquired packet identification information to one or a plurality of the second external devices;
Packet identification information receiving means for receiving packet identification information transmitted from one or more third external devices;
A content reception / playback apparatus comprising: decoding processing means for decoding the received stream using the received packet identification information. Dividing at least one of video and audio included in one or more contents into a plurality of packets, and adding packet identification information that allows each packet to be identified to a packet including program identification information that identifies the packet and the content, One or a plurality of content playback apparatuses and a communication network that receive each stream from an external device that multiplexes each packet with the packet identification information added and transmits the multiplexed packet and transmits the content included in the received stream. A content receiving method that is executed by a content receiving device that is connected via the external device and receives the stream from the external device,
A program identification information acquisition step for acquiring the program identification information from the received stream;
A packet identification information acquisition step for acquiring packet identification information of a packet included in the received stream from the acquired program identification information;
And a packet identification information transmitting step of transmitting the acquired packet identification information to one or a plurality of the content reproduction devices. Dividing at least one of video and audio included in one or more contents into a plurality of packets, and adding packet identification information that allows each packet to be identified to a packet including program identification information that identifies the packet and the content, Each packet to which packet identification information is added is multiplexed and transmitted from an external device that transmits it as one stream, the program identification information is acquired from the received stream, and the program identification information is acquired from the acquired program identification information. The content included in the received stream is obtained by acquiring packet identification information for identifying a packet included in the stream, connected to a content receiving apparatus that transmits the acquired packet identification information via a communication network, receiving the stream, and Executed by a content playback device that plays back A raw way,
A packet identification information receiving step for receiving the packet identification information transmitted from the content receiving device;
And a decoding process step of decoding the received stream using the received packet identification information. Dividing at least one of video and audio included in one or more contents into a plurality of packets, and adding packet identification information that allows each packet to be identified to a packet including program identification information that identifies the packet and the content, Multiplex each packet with packet identification information added, receive the stream from the first external device that transmits as one stream, acquire program identification information identifying each content from the received stream, and acquire A third external device that acquires packet identification information for identifying a packet included in the stream from the program identification information, and transmits the acquired packet identification information to one or a plurality of second external devices that reproduce the content; and,
Receiving the stream from the first external device, receiving packet identification information transmitted from the third external device, and decoding the received stream using the received packet identification information; A content reception / playback apparatus that is connected to at least one of the second external devices that plays back the content included in the received stream via a communication network, receives the stream from the first external device, and plays back the stream. A content receiving / playing method for
A program identification information acquisition step for acquiring the program identification information from the received stream;
A packet identification information acquisition step for acquiring packet identification information of a packet included in the received stream from the acquired program identification information;
A packet identification information transmission step of transmitting the acquired packet identification information to one or more second external devices;
A packet identification information receiving step for receiving packet identification information transmitted from one or more third external devices;
And a decoding process step of decoding the received stream using the received packet identification information.   A content reproduction system comprising: the content reception device according to any one of claims 1 to 4; and the content reproduction device according to any one of claims 5 to 8.   A content reproduction system comprising at least one content reception / reproduction device according to claim 9.   A program for operating the content receiving device according to any one of claims 1 to 4, wherein the program causes a computer to function as each means described above.   A program for operating the content reproduction apparatus according to any one of claims 5 to 8, wherein the program causes a computer to function as each of the means.   A program for operating the content reception / playback apparatus according to claim 9 for causing a computer to function as each of the above means.   The computer-readable recording medium which recorded the program of any one of Claim 15 to 17.

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