JP6490284B2 - Content distribution system - Google Patents

Description

  The present invention relates to a content distribution system for multicast distribution of moving image content such as television broadcasting.

  Various video distribution services such as a television broadcast distribution service that distributes a television broadcast using a communication network are provided. In television broadcasting, it is preferable to use multicast transmission because many viewers watch at the same time (Patent Document 1 and Patent Document 2). By the way, in the Internet, HTTP is often used as a higher-level protocol, and a moving image distribution service for transmitting a moving image in accordance with HTTP is provided (for example, HTTP Live Streaming of Apple Inc., USA). In such a moving image distribution service, a plurality of moving image segment files are distributed with reference to playlist information. However, when trying to realize a video distribution service compliant with HTTP by multicast transmission, since connectionless UDP is used, a communication loss is likely to occur, which causes a reproduction loss for each segment file. In the case of normal digital television broadcasting, information loss occurs in units of MPEG2-TS packets (188-byte fixed length), and stripe noise with a thickness of 16 dots appears in the horizontal direction for about 0.5 seconds. However, if information loss occurs in segment file units due to IP multicast UDP packets, the video stops for several seconds to several tens of seconds.

  The above-described prior art and its problems are described only to explain a part of the background of the present invention. It should be noted that the present invention is not limited to the above-described prior art and problems.

JP 2002-185943 A Special table 2003-522442 gazette

  The present invention has been made in consideration of the above circumstances, and is a content distribution technique that uses IP multicast communication and further reduces reproduction loss as much as possible when distributing video in compliance with HTTP. It is intended to provide.

  According to this invention, in order to achieve the above-mentioned object, the configuration as described in the claims is adopted. Here, prior to describing the invention in detail, supplementary explanations of the claims will be given.

  According to one aspect of the present invention, in order to achieve the above-described object, a moving image content processing apparatus connectable to a communication network: a UDP packet that is transmitted by IP multicast after disassembling a moving image file including a plurality of TS packets A moving picture file reconstructing means for reconstructing the moving picture file from a UDP packet received by the UDP packet receiving means; and the moving picture file reconstructed by the moving picture file reconstructing means in the communication network. And transmitting means for transmitting to the user terminal via HTTP; the moving image file reconstructing means receives at least one UDP packet among a plurality of UDP packets corresponding to the moving image file. If there is no So that to rebuild the video file.

  According to another aspect of the present invention, in order to achieve the above-mentioned object, a user terminal connectable to a communication network: reproduction means for reproducing a moving image file including a plurality of TS packets; and a plurality of TS packets UDP packet receiving means for disassembling a moving image file containing IP packets received by IP multicast transmission; reconstructing the moving image file from the UDP packet received by the UDP packet receiving means and reproducing the information in accordance with HTTP A moving image file reconstructing means for supplying to the means; the moving image file reconstructing means is complete when at least one UDP packet of a plurality of UDP packets corresponding to the moving image file is not received. The video file is reconstructed in a mode that includes only TS packets.

  According to another aspect of the present invention, in order to achieve the above-mentioned object, a computer program allows a user terminal connectable to a communication network: a reproduction means for reproducing a moving image file including a plurality of TS packets; UDP packet receiving means for decomposing a moving picture file including a TS packet and receiving a UDP packet sent by multicast transmission; reconstructing the moving picture file from the UDP packet received by the UDP packet receiving means and complying with HTTP Used for realizing as a moving image file reconstructing means to be supplied to the reproducing means; the moving image file restructuring means does not receive at least one UDP packet among a plurality of UDP packets corresponding to the moving image file; The above video frame is included in a manner that includes only complete TS packets. It is adapted to reconstruct the file.

  According to another aspect of the present invention, in order to achieve the above-described object, a computer program can be used to dispose a moving image content processing apparatus connectable to a communication network: a moving image file including a plurality of TS packets and an IP UDP packet receiving means for receiving a UDP packet transmitted by multicast; a moving picture file reconstructing means for reconstructing the moving picture file from the UDP packet received by the UDP packet receiving means; and the moving picture reconstructed by the moving picture file reconstructing means Used to realize a transmission means for transmitting a file to the user terminal via the communication network in conformity with HTTP; the moving picture file reconstructing means includes at least one of a plurality of UDP packets corresponding to the moving picture file; Does not accept one UDP packet The case, so as to reconstruct the moving picture file in a manner that includes only complete TS packet.

  In this configuration, the moving image file may be reconstructed in such a manner that only a complete TS packet is included in the portion corresponding to the UDP packet that has not been received using a null packet of the TS packet.

  In this configuration, the first processing device may prevent any TS packet from being divided across two adjacent UDP packets.

  In this configuration, the UDP packet transmitted from the first processing device includes a plurality of complete TS packets and a pad unit, and the second processing device includes the complete UDP packet included in the received UDP packet. The moving image content processing apparatus according to claim 6, wherein the moving image file is reconstructed from a plurality of TS packets.

  In this configuration, the moving image file includes HTTP Live Streaming (trademark of Apple Inc., USA), MPEG-DASH (ISO / IEC 2309-1), HTTP Dynamic Streaming (trademark of Adobe Systems Inc., USA), or Smooth Stream (trademark of USA). It may be transmitted by the HTTP streaming technique of Microsoft Corporation (USA).

  Furthermore, the technical features described here will be summarized. According to one aspect of the technical features described herein, in order to achieve the above-described object, the moving image content distribution system includes: a first moving image file including a plurality of TS packets into UDP packets and IP multicast transmission; And a second processing device that receives a UDP packet transmitted by IP multicast from the first processing device, reconstructs it into a moving image file, and transmits it to the user terminal in accordance with HTTP. And the second processing device reconstructs the moving image file in such a manner that only the complete TS packet is included when at least one UDP packet of a plurality of UDP packets corresponding to the moving image file is not received. I am doing so.

  The TS packet is a packet constituting a transport stream (transport stream packet), and is typically an MPEG-2 TS packet defined by the MPEG2-TS (Moving Picture Experts Group 2 Transport Stream) standard. However, it is not limited to this.

  The moving image file may include video data and audio data. Typically, the moving image file typically includes HTTP Live Streaming (Apple Inc., USA), MPEG-DASH (ISO / IEC 2309-1), HTTP Dynamic Streaming (Adobe Systems Inc., USA), and Smooth. It may be a moving image file (segment file) transmitted by an HTTP streaming method such as Streaming (Microsoft Corporation, USA).

  In this configuration, the moving image file may be reconstructed in such a manner that only a complete TS packet is included using a null packet (NULL packet) of a TS packet in a portion corresponding to the UDP packet not received.

  The null packet (NULL packet) indicates that the content of the packet is invalid, and all the bits including the header are “1”. Instead of a null packet, when playing a video, a packet indicating that the contents of the packet cannot be used, or if the playback side can be interpreted as such, such a specific packet is May be adopted. Alternatively, the packet may be a packet in which the transport error indicator flag in the header of the MPEG-2 TS packet is set to “1”.

  Further, the first processing apparatus may prevent any TS packet from being divided across two preceding and following UDP packets.

  In this case, the UDP packet transmitted from the first processing device may include a plurality of complete TS packets and a pad unit, and the second processing device may include the complete UDP packet included in the received UDP packet. The moving image file may be reconstructed from a plurality of TS packets.

  The first processing device may receive a moving image file including a plurality of TS packets from the moving image server in conformity with HTTP, disassemble the moving image file into UDP packets, and transmit the multicast file by multicast transmission.

  Further, according to another aspect of the technical feature described here, in order to achieve the above-described object, the above-described object is received by receiving a UDP packet transmitted by IP multicast by disassembling a moving image file including a plurality of TS packets. A processing device for reconstructing a moving image file reconstructs the moving image file in such a manner that only a complete TS packet is included when at least one UDP packet of a plurality of UDP packets corresponding to the moving image file is not received. .

  Further, according to another aspect of the technical feature described here, in order to achieve the above-described object, the above-described object is received by receiving a UDP packet transmitted by IP multicast by disassembling a moving image file including a plurality of TS packets. When a user terminal that reconstructs and plays back a moving image file does not receive at least one UDP packet among a plurality of UDP packets corresponding to the moving image file, the user terminal displays the moving image file in a mode including only a complete TS packet. Rebuild.

  According to another aspect of the technical features described herein, in order to achieve the above-described object, a computer program can disassemble a user terminal that can be connected to a communication network: a video file including a plurality of TS packets. Means for receiving a UDP packet transmitted by IP multicast; means for reconstructing the moving image file from the received UDP packet; means for realizing and reconstructing the reconstructed moving image file When not receiving at least one UDP packet among a plurality of UDP packets corresponding to the moving image file, the moving image file is reconstructed so as to include only a complete TS packet.

  Also, according to another aspect of the technical feature described here, the first aspect of the present invention is a video content distribution system: a first method of decomposing a video file including a plurality of TS packets received from an HTTP server into UDP packets and performing IP multicast transmission A processing device; and a second processing device that receives a UDP packet transmitted from the first processing device by IP multicast and reconstructs it into a moving image file and transmits it to the user terminal in conformity with HTTP. Yes.

  According to still another aspect of the technical feature described herein, the moving image distribution system includes: a first processing device that decomposes a moving image file including a plurality of TS packets into UDP packets and transmits the IP multicast; A second processing device that receives a UDP packet transmitted from an IP multicast from the first processing device, reconstructs it into a moving image file, and transmits it to a user terminal in accordance with HTTP; When an UDP request corresponding to the HTTP header is not received, an HTTP response indicating that the content length is zero is received when an HTTP request is received from the client device to transmit a moving image file including the UDP packet. I am trying to return it.

  When the HTTP header portion of the video file is not accurately described due to the loss of the UDP packet, there is a problem that the playback freezes. However, in this configuration, the playback of the video file is skipped, and the subsequent video file Can be appropriately reproduced.

  The present invention can be realized not only as an apparatus or a system but also as a method. Of course, a part of the invention can be configured as software. Of course, software products used to cause a computer to execute such software are also included in the technical scope of the present invention.

  These and other aspects of the invention are set forth in the appended claims and will be described in detail below with reference to examples.

It is a figure explaining the environment where the moving image content delivery system of the Example of this invention is performed. It is a figure explaining the outline | summary of the operation example of the moving image content delivery system of FIG. It is a functional block diagram which shows the structural example of the file packetization apparatus 300 of FIG. It is a figure explaining the example of packetization of an HTTP file. It is a functional block diagram which shows the structural example of the file reconstruction apparatus 400 of FIG. It is a figure explaining the operation example of the file reconstruction apparatus 400 of FIG. It is a figure explaining the operation example of the null packet insertion part 403 of FIG. It is a functional block diagram explaining the structural example of the portable terminal which makes the non-UDP corresponding terminal device 600 of FIG. It is a figure explaining the moving image delivery service of the conventional HTTP conformity. It is a figure explaining the operation example of the moving image delivery service of FIG. It is a figure explaining the HTTP message | telegram sample in the operation example of FIG. It is a functional block diagram which shows the structural example of the UDP corresponding | compatible terminal device 700 of FIG. It is a figure explaining a modification.

  Examples of the present invention will be described below.

  FIG. 1 shows an embodiment of a moving image content distribution system according to the present invention. In this drawing, a moving image content distribution system 100 includes an HTTP distribution server 200, a file packetizing device 300, a file reconstruction device 400, a content distribution. The network 500, the UDP non-compliant terminal device 600, and the UDP compatible terminal device 700 are included. As will be described later, the file reconstruction device 400 receives a UDP packet from the file packetization device 300 by IP multicast, and a plurality of file reconstruction devices 400 are typically provided. Although only one UDP-incompatible terminal apparatus 600 and UDP-compatible terminal apparatus 700 are shown in the figure, a plurality of terminals are typically provided. The non-UDP compatible terminal apparatus 600 can determine which file restructuring apparatus 400 is to be accessed based on position information and the like.

  The content distribution network 500 is a network that can efficiently implement unicast communication and multicast communication. The content distribution network 500 preferably uses a dedicated network service in order to efficiently realize multicast communication, but is not limited thereto.

  The HTTP distribution server 200 distributes moving image content, for example, a television broadcast content file using HTTP. The HTTP distribution server 200 is a server that transmits a video content to a client in accordance with HTTP and distributes moving image content. For example, the HTTP distribution server 200 is an HLS (HTTP Live Streaming) system manufactured by Apple Inc., and is a Web server that is compliant with HTTP. It is feasible. In this example, the HTTP distribution server 200 is connected to a communication network (not shown), but may be connected to the content distribution network 500. Further, the non-UDP compatible terminal device 600 or the like may use the moving image content distribution service from the HTTP distribution server 200 by IP unicast, as in the conventional mode.

  The moving image distribution service compliant with HTTP prepares a playlist file (for example, m3u8 file) and one or more moving image segment files (MPEG2-TS segment file) as shown in FIG. In the example of FIG. 9, a plurality of (two) alternative playlists having different resolutions can be selected using the master index file. There may be only one playlist. The alternative playlist (playlist) may be rewritten and repeatedly transmitted. Moving image segment files can be sequentially retrieved with reference to the playlist.

  Similar to the conventional HTTP procedure shown in FIG. 10, the HTTP distribution server 200 performs a master index file, a substitution based on a playlist request (master index, a substitute playlist request) from the file packetizing apparatus 300 that is an HTTP client. A playlist file (hereinafter sometimes simply referred to as a playlist) is returned to the file packetizing apparatus 300. After that, the HTTP distribution server 200 sequentially returns the moving image segment file in response to the segment request from the file packetizing apparatus 300. The moving image segment file includes, for example, an MPEG2-TS packet.

  The file packetizing apparatus 300 receives a playlist file and a moving image segment file of the moving image distribution service as a client of the HTTP distribution server 200, divides these files into UDP packets, and transmits them by IP multicast in a predetermined multicast group. As illustrated in FIG. 3, the file packetizing apparatus 300 includes an HTTP client processing unit 301, a storage unit 302, a packetizing unit 303, and a transmission unit 304.

  The HTTP client processing unit 301 of the file packetizing apparatus 300 receives a playlist file and a video segment file from the HTTP distribution server 200. The (a) column of FIG. 4 shows an example of a video segment file received by the HTTP client processing unit 301. The storage unit 302 stores the received file. The packetizing unit 303 decomposes the file received by the HTTP client processing unit 301 into a UDP packet. The (b) column in FIG. 4 is obtained by decomposing the moving image segment file in the (a) column in FIG. 4 into UDP packets. The moving image segment file in the column (a) of FIG. 4 is typically data having a length of several seconds to several tens of seconds, but is not limited thereto. The UDP packet in the (b) column of FIG. 4 includes a packetization header, an HTTP header, and a payload. As shown in the (c) column, the packet header includes a header size (header_size), a stream identifier (stream_id), and a start flag. (Start_flag), total size (total_size), payload size (payload_size), and payload offset (payload_offset). The header size (header_size) indicates the total size of the packetization header and the HTTP header, the stream identifier (stream_id) is an identifier indicating to which file the UDP packet belongs, and the start flag (start_flag) is the head The total size (total_size) indicates the total number of bytes of the file, the payload size (payload_size) indicates the number of bytes of the file portion sent in the UDP packet, and the payload offset. (Payload_offset) indicates the start position of the file portion sent in the UDP packet. In addition, a forward error correction code (FEC) or the like may be included. The UDP packet typically has a fixed length of 1500 bytes or less according to Ethernet, but is not limited thereto. The TS packet of the moving image content is included in one UDP packet without being divided, and if there is a remainder in the payload portion of each UDP packet, an embedded portion (pad) may be included.

  The playlist file is similarly converted into a UDP packet, except for considerations related to TS packets.

  The transmission unit 304 designates a multicast group and distributes a UDP packet by IP multicast.

  The file reconstruction device 400 appropriately joins the multicast group of the file packetization device 300, receives a UDP packet transmitted from the file packetization device 300 via the content distribution network 500 by IP multicast, and plays the playlist file. And rebuild the video segment file.

  As shown in FIG. 5, the file reconstruction apparatus 400 includes a UDP packet receiving unit 401, a UDP packet loss detecting unit 402, a null packet inserting unit 403, a packet connecting unit 404, a storage unit 405, and an HTTP service unit 406. The UDP packet receiving unit 401 participates in the IP multicast group and receives a UDP packet at the destination port. When the UDP packet constituting the video segment file is not received, the UDP packet loss detection unit 402 detects this based on, for example, payload-size, CRC check code, checksum, etc., and further detects the UDP packet at the loss position as payload- In place of this, the null packet insertion unit 403 inserts a null packet of the TS packet (FIG. 6). A null packet is a packet in which all bits including the header have a value of “1”. The playlist file is repeatedly transmitted. Therefore, when a UDP packet loss is detected, the file may be discarded and reception of the playlist file sent next time may be waited. Whether the UDP packet is of a video segment file or a playlist file can be determined based on the content type included in the HPPT header of the UDP packet. For example, as shown in FIG. 7A, “Content-Type: video” In the case of “/ MP2”, it is determined that it is a UDP packet of a moving image segment file, and a null packet of a TS packet is inserted in the lost portion. Alternatively, as shown in FIG. 7B, an NP (NULL Packet) complement flag field may be provided in the HTTP header, and the NP complement flag may be flagged in the HTTP header of the UDP packet of the video segment file.

  When a UDP packet is assigned a serial number, the UDP packet detection unit 402 may determine the loss of the UDP packet based on its continuity.

  Examples of HTTP messages for playlist responses and segment file responses are as shown in FIGS. 11A and 11B, and “Content-Type” is underlined.

  The packet concatenation unit 404 reorders the UDP packets based on the layload-offset or the like, and reconstructs the file by inserting a null packet of the TS packet at the missing position of the moving image segment file. When the file is reconstructed, unnecessary padding (Pad) is removed. A predetermined file storage management unit stores and manages the reconstructed playlist file and moving image segment file in the storage unit 405.

  The HTTP service unit 406 returns the playlist file and the video segment file to the UDP non-compliant terminal device 600 in the same manner as shown in FIG. 10 based on the HTTP request from the UDP non-compliant terminal device 600. The terminal device 600 that does not support UDP reproduces a moving image based on the received file. The terminal device 600 that does not support UDP may be any device as long as it can function as an HTTP terminal, and is typically a mobile terminal such as a smartphone, but is not limited to this, and any information terminal (information computerization) Home appliances).

  An example of a portable terminal constituting the non-UDP compatible terminal device 600 is as shown in FIG. In FIG. 8, the portable terminal 800 includes a processing system 810, a memory 820, an input / output subsystem 830, a high frequency circuit unit 840, and an audio circuit unit 850. Each of the components can be realized as appropriate by hardware including a signal processing integrated circuit and an application specific integrated circuit, software, or a combination thereof. The high-frequency circuit unit 840 is used to transmit / receive information to / from other devices over a wireless link or network, and to perform this function, an antenna system, an RF transceiver, an amplifier, a tuner, an oscillator, Including, but not limited to, digital signal processors, CODEC chip sets, memories, and other known circuit configurations. The high frequency circuit unit 840 includes mobile communication such as time division multiple access (TDMA) and code division multiple access (CDMA), wireless LAN (IEEE 802.11b, IEEE 802.11a, IEEE 802.11g and / or IEEE 802.11N), Bluetooth, and the like. Although communication protocols such as (IEEE802.15.1) and Wi-MAX (IEEE802.16) can be used, the present invention is not limited to this. The audio circuit unit 850 is connected to the audio speaker 851 and the microphone 852. The processing system 810 includes a processor 811, a memory controller 812, and a peripheral device interface 813. A memory 820 stores codes and data executed by the processor 811. The memory 820 may include any storage device such as RAM, ROM, FLASH, disk drive, magnetic tape and the like. The processor 811 executes various software components stored in the memory 820. For example, the software components include an operating system 821, a communication module 822, a contact / operation module 823, a graphics module 824, an application 825, a timer module 826, and a web browser module 827. The application 825 includes a position determination function such as a browser, an address book, e-mail, encryption, a global positioning system (GPS), and a moving image content reproduction function. In this embodiment, the mobile terminal operates as, for example, a terminal device 600 that does not support UDP, and at least a part of the HTTP client and the moving image playback unit is realized as the application 825. By installing a corresponding application in the memory 820, the portable terminal 800 is caused to function as an HTTP client and a moving image playback unit.

  The UDP-compatible terminal device 700 has the function of the file restructuring device 400, receives a UDP packet distributed by IP multicast from the file packetizing device 300, and reconstructs a playlist file and a video segment file. It is to play a movie. The UDP-compatible terminal device 700 can cope with UDP packet loss by a functional unit equivalent to the UDP packet loss detection unit 402 and the null packet insertion unit 403 of the file reconstruction device 400. The UDP-compatible terminal device 700 can be realized by the mobile terminal shown in FIG. That is, as shown in FIG. 12, the UDP-compatible device 700 includes a UDP packet receiving unit 701, a UDP packet loss detecting unit 702, a null packet inserting unit 703, a packet connecting unit 704, a storage unit 705, and a moving image reproducing unit 706. Composed. Among these, the UDP packet receiving unit 701, the UDP packet loss detecting unit 702, the null packet inserting unit 703, the packet linking unit 704, and the storage unit 705 are the UDP packet receiving unit 401 and the UDP packet loss detecting unit of the file reconstruction device 400. 402, the null packet insertion unit 403, the packet concatenation unit 404, and the storage unit 405 may be configured similarly. The moving image reproducing unit 706 reproduces a moving image using the playlist file and the moving image segment file stored in the storage unit 705. In this case, the file may be directly accessed, or the file may be acquired in accordance with HTTP. The UDP packet receiving unit 701, the UDP packet loss detecting unit 702, the null packet inserting unit 703, the packet connecting unit 704, and the like shown in FIG. 12 may be realized by the application 825 of the mobile terminal 800.

  FIG. 2 shows the overall operation of the moving image content distribution system 100 of FIG. In FIG. 2, the moving image content is sent from the HTTP distribution server 200 to the file packetizing device 300 by IP unicast, further sent from the file packetizing device 300 to the file restructuring device 400 by IP multicast, It is sent to the corresponding terminal device 600 by IP unicast. Although not shown in FIG. 2, the UDP-compatible terminal device 700 is disposed at the position of the file reconstruction device 400, receives moving image content from the file packetizing device 300 by IP multicast, and reproduces the moving image.

  First, the file packetizing apparatus 300 sends a playlist file acquisition request to the HTTP distribution server 200 (X01). In response to this, the HTTP distribution server 200 returns the playlist to the file packetizing apparatus 300 (X02). Thereafter, the file packetizing apparatus 300 sequentially sends an acquisition request for the video segment files described in the playlist to the HTTP delivery server 200 (X03), and the HTTP delivery server 200 sequentially sends the video segment files accordingly. It returns to the file packetizing apparatus 300 (X04).

  The file packetizing apparatus 300 disassembles the received playlist file and moving image segment file into UDP packets and distributes them to the file reconstruction apparatus 400 by IP multicast (X05). The above processes X01 to X05 are repeatedly executed.

  The file reconstruction device 400 reconstructs the playlist file and the moving image segment file from the received UDP packet, and stores and retains them in the storage unit 405 (X06, X07). If there is a UDP packet loss during reconstruction of the moving image segment file, it is replaced with a null packet. If there is a loss of UDP packets when the playlist file is reconstructed, the playlist file that is being constructed is discarded, and the playlist file that is distributed next time is reconstructed.

  The file restructuring device 400 functions as an HTTP server for the terminal device 600 that does not support UDP. That is, the UDP non-compliant terminal apparatus 600 sends a playlist file acquisition request to the file reconstruction apparatus 400 (X08). In response to this, the file reconstruction device 400 returns the playlist to the UDP non-compliant terminal device 600 (X09). After that, the UDP non-compliant terminal device 600 sequentially sends an acquisition request for the video segment file described in the playlist to the file restructuring device 400 (X10), and the file restructuring device 400 responds accordingly to the video segment file. Are sequentially returned to the non-UDP compatible terminal device 600 (X11). The terminal device 600 that does not support UDP sequentially generates moving images based on the moving image segment file.

  This is the end of the description of the embodiment.

  In addition, this invention is determined based on description of a claim, and is not limited to the specific structure of the Example, a subject, and an effect. The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the above example, the null packet of the TS packet is inserted in the portion corresponding to the lost UDP packet. However, if only the complete TS packet is included, the null packet of the TS packet may not be inserted. For example, in the example of FIG. 6, the file may be reconstructed to include a complete HTTP header and a complete TS packet included in a successfully received UDP packet, except for null packets.

  In addition, when the lost UDP packet of the segment file corresponds to the HTTP header, the HTTP header is lost. In order to cope with this, when there is an HTTP request from the client for the segment file, an HTTP response indicating that the content length (Content-Length) is zero, for example, an HTTP response as shown in FIG. 13 is returned. Good. In FIG. 13, the description of the content length is indicated by an arrow. In this configuration, the reproduction of the moving image file is skipped, and the subsequent moving image file can be reproduced appropriately, for example, at a timing based on the time stamp of the TS stream. The HTTP response does not include the main body.

  In the above-described example, the file packetizing apparatus 300 acquires the file for video distribution conforming to HTTP from the HTTP distribution server 200 using HTTP. However, these files are generated and generated by the file packetizing apparatus 300 itself. It may be prepared or obtained from any source.

100 video content distribution system 200 HTTP distribution server 300 file packetization device 400 file reconstruction device 500 content distribution network 600 non-UDP compatible terminal device 700 UDP compatible terminal device 800 portable terminal

Claims (2)

In a user terminal that can be connected to a communication network,
Playback means for playing back a moving image file including a plurality of TS packets;
UDP packet receiving means for decomposing a video file including a plurality of TS packets and receiving a UDP packet transmitted by IP multicast;
A moving image file reconstructing means that reconstructs the UDP packet received from the UDP packet receiving means into the moving image file and supplies it to the reproducing means in accordance with HTTP;
The moving image file reconstructing means reconstructs the moving image file in a mode including only a complete TS packet when not receiving at least one UDP packet among a plurality of UDP packets corresponding to the moving image file. Characteristic user terminal. A user terminal that can be connected to a communication network
Reproduction means for reproducing a moving image file including a plurality of TS packets,
UDP packet receiving means for decomposing a video file including a plurality of TS packets and receiving a UDP packet transmitted by multicast,
A moving image file reconstructing unit configured to reconstruct the moving image file from the UDP packet received by the UDP packet receiving unit and supply the reconstructing unit in accordance with HTTP;
Used to realize as
The moving image file reconstructing means reconstructs the moving image file in a mode including only a complete TS packet when not receiving at least one UDP packet among a plurality of UDP packets corresponding to the moving image file. A featured computer program.

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