JP4971705B2 - Content receiving device, content transmitting device, basic data synchronization method, and content receiving program - Google Patents

Description

  The present invention relates to a content receiving device, a content transmitting device, a basic data synchronization method, and a content receiving program that receive and transmit content via a network.

  When a program is produced at a broadcasting station, a plurality of contents such as video and audio are edited by an editing device to produce one complete program. In this editing apparatus, it is necessary to reproduce a plurality of contents synchronously. Here, in order to synchronize and reproduce a plurality of contents, it is necessary to achieve two levels of synchronization: system level synchronization and time code level synchronization.

  System level synchronization means that if the editing device is composed of a plurality of equipment such as a VTR (Video Tape Recorder), a video switcher, a video processing device, an audio processing device, etc., these devices are operated with the same clock. Is for. The system level synchronization is performed by supplying a synchronization signal output from the same synchronization signal generator to all devices.

  Next, time code level synchronization will be described. Time information called a time code is assigned to each content frame such as video material and audio material used in a broadcasting station (see Non-Patent Document 1). When editing a program, the time code is used to specify where to use each content. Furthermore, in order to accurately process the content of video material and audio material at the position of the time code intended by the program producer, it is necessary to reproduce a plurality of contents in synchronization with the time code. This is time code level synchronization.

Here, when the synchronization of the time code level is shifted, for example, the movement of the lips of the person displayed as a video and the sound being played simultaneously are shifted and reproduced. Conventionally, there have been methods for delaying playback on one side, such as inserting a frame synchronizer having a frame memory on the video playback side or inserting a delay line on the audio playback side, in order to deal with such synchronization of time code levels. It was.
SMPTE12M-1999 "Television, Audio and Film-Time and Control Code"

  In recent years, due to the development of network technology such as IP (Internet Protocol) network, a method of storing contents in different servers and using those contents via the network has been studied. In the case where contents are stored in the contents, there is a problem that the time code levels of these contents cannot be synchronized.

  For example, when content is acquired from two servers (content transmission devices) connected via a network having RTT (Round Trip Time) of 400 milliseconds and 1 millisecond, respectively, from the content reception device Even if simultaneous playback requests are made to the server, there is a difference of about 12 frames in reaching the content receiving device. Therefore, if it is reproduced as it is, a video with a difference of 12 frames is generated. Although this delay can be adjusted by inserting a frame memory, etc., the RTT between the content transmitting device and the content receiving device when transmitting / receiving content via the network differs depending on the connection path of the network. With the insertion of a typical delay device, there is a problem that adjustment is required every time content frame data is received.

  The present invention has been made to solve the above-described problems of the prior art, and is a content receiving apparatus that can synchronize at the system level and time code level during reproduction even when content is transmitted and received via networks with different delay times. An object of the present invention is to provide a content transmission device, a basic data synchronization method, and a content reception program.

  In order to solve the above-described problem, the content receiving device according to claim 1 is connected to a network in a plurality, and the basic data of content data configured with basic data of a predetermined length as a unit is a data packet unit for network transmission. A content receiving apparatus that receives the data packet from the content transmitting apparatus that transmits the network via the network and reconstructs the content data in units of the basic data, the synchronization packet transmitting means, the packet receiving means, and the basic The data reconstruction means, basic data storage means, delay signal generation means, and basic data output means are provided.

  According to such a configuration, the content receiving device synchronizes with the basic clock indicating the timing of reproducing the basic data by the synchronization packet transmitting means, and includes the synchronization packet including basic data specifying information for specifying the basic data in the content transmitting device. Send. Further, the content receiving apparatus receives, from the content transmitting apparatus, basic data data packets corresponding to the basic data specifying information of the synchronous packets transmitted from the synchronous packet transmitting means by the packet receiving means.

Further, the content receiving apparatus reconstructs basic data from the data packet received by the packet receiving means by the basic data reconstructing means, and stores it in the basic data storage means. In addition, the content receiving device generates a delay signal that is delayed from the basic clock by the same delay amount as that of other content receiving devices connected to the network, from the basic clock, and outputs basic data. Based on this delay signal, the means reads basic data corresponding to the basic data specifying information from the basic data storage means and outputs it.

As a result, the content receiving apparatus can receive the basic data from the content transmitting apparatus in units of data packets, and can reconstruct and output the basic data from the data packets. Further, since the content receiving device stores the basic data in the basic data storage means, and reads out and outputs the basic data based on the delay signal, the network is preset from the time when the synchronization packet is transmitted regardless of the delay time in the network. The basic data can be output at the time when the same delay amount as that of other content receiving apparatuses connected to the elapses.

  Further, the content transmission device according to claim 2 is connected to a network, and the basic data corresponding to the basic data specifying information for specifying the basic data of the content data configured with basic data of a predetermined length as a unit, A content transmitting apparatus for transmitting data to the content receiving apparatus according to claim 1 via the network in units of data packets for network transmission, comprising: synchronization packet receiving means; basic data input means; and packet transmitting means. It was set as the structure provided.

  According to this configuration, the content transmission device receives the synchronization packet including the basic data specifying information from the content reception device by the synchronization packet receiving unit. Further, the content transmitting apparatus inputs basic data corresponding to the basic data specifying information included in the synchronization packet received by the synchronous packet receiving means from the outside by the basic data input means, and the basic data is input by the packet transmitting means. The data packet is divided, and a data packet is generated and transmitted to the content receiving apparatus.

  As a result, the content transmitting apparatus can transmit basic data corresponding to the basic data specifying information included in the synchronization packet transmitted from the content receiving apparatus to the content receiving apparatus in units of data packets.

  Further, the basic data synchronization method according to claim 3 is a content transmission apparatus that transmits the basic data of content data configured in units of basic data of a predetermined length via the network in units of data packets for network transmission. A basic data storage device for storing the basic data, a plurality of content receiving devices connected to a network receiving the data packet, and reconfiguring and outputting the content data in units of the basic data A data synchronization method comprising a synchronization packet transmission step, a packet reception step, a basic data reconstruction step, a basic data storage step, and a basic data output step.

According to this method, in the synchronization packet transmission step, the synchronization packet including the basic data specifying information for specifying the basic data is transmitted to the content transmitting device in synchronization with the basic clock indicating the timing for reproducing the basic data. In the receiving step, a data packet of basic data corresponding to the basic data specifying information of the synchronization packet is received from the content transmitting apparatus. Subsequently, in the basic data reconstruction step, basic data is reconstructed from the data packet received in the packet reception step, and in the basic data storage step, the basic data is stored in the basic data storage device. Then, in the basic data output step, the basic data is specified from the basic data storage device based on the delay signal set in advance from the basic clock and delayed by the same delay amount as other content receiving devices connected to the network. Read and output basic data corresponding to information.

As a result, basic data can be received from the content transmitting apparatus in units of data packets, and the basic data can be reconstructed from the data packets and output. In addition, the basic data is stored in the basic data storage device, and is read out and output based on the delay signal. Therefore, regardless of the delay time in the network, other than those connected to the network set in advance from the time when the synchronization packet is transmitted. Basic data can be output at the time when the same delay amount as that of the content receiving apparatus has elapsed.

  According to a fourth aspect of the present invention, there is provided a content receiving program from a content transmitting apparatus that transmits the basic data of content data configured in units of basic data of a predetermined length via the network in units of data packets for network transmission. Receiving the data packet, reconstructing the content data in units of the basic data, storing the basic data in a basic data storage device storing the basic data, and reading and outputting the basic data from the basic data storage device Therefore, the computer is caused to function as a synchronous packet transmission unit, a packet reception unit, a basic data reconstruction unit, a delay signal generation unit, and a basic data output unit.

According to such a configuration, the content receiving program synchronizes with the basic clock indicating the timing of reproducing the basic data by the synchronous packet transmitting unit, and includes the synchronization packet including basic data specifying information for specifying the basic data in the content transmitting device. Send. Further, the content receiving program receives, from the content transmitting apparatus, a basic data data packet corresponding to the basic data specifying information of the synchronous packet transmitted from the synchronous packet transmitting unit by the packet receiving unit. Further, the content receiving program reconstructs basic data from the data packet received by the packet receiving means by the basic data reconstructing means and stores it in the basic data storage device. Further, the content reception program generates a delay signal that is delayed from the basic clock by the same delay amount as that of another content reception device connected to the network, from the basic clock, and outputs basic data. Based on the delay signal, the basic data corresponding to the basic data specifying information is read out from the basic data storage device and output.

As a result, the content receiving program can receive basic data from the content transmitting apparatus in units of data packets, and can reconstruct and output the basic data from the data packets. Further, since the content receiving program stores basic data in the basic data storage device, and reads and outputs the basic data based on the delay signal, the network is preset from the time when the synchronization packet is transmitted regardless of the delay time in the network. The basic data can be output at the time when the same delay amount as that of other content receiving apparatuses connected to the elapses.

  The content reception device, content transmission device, basic data synchronization method, and content reception program according to the present invention have the following excellent effects. According to the first, third, or fourth aspect of the present invention, the basic data is specified at a time determined by the basic clock and a preset delay amount regardless of the delay time of data packet transmission in the network. Since basic data corresponding to information can be output, even when multiple contents are received via the network with different delay times, by setting a common basic clock and delay amount, Basic data can be output in synchronization at the system level and the time code level.

  According to the second aspect of the present invention, the basic data can be transmitted to the content receiving device based on the synchronization packet transmitted from the content receiving device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Contents transmission / reception system configuration]
First, a configuration of a content transmission / reception system S including a content transmission device 1 and a content reception device 5 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a content transmission / reception system including a content transmission device and a content reception device according to the present invention.

  The content transmission / reception system S reads out the content from the content storage devices 3, 3,... That store content (content data) such as video and audio by the corresponding content transmission devices 1, 1,. This is a system for transmitting to the content receiving devices 5, 5,... Via the network N. Here, the content transmission devices 1, 1,... And the content reception devices 5, 5,. Further, content storage devices 3, 3,... Are connected to the content transmission devices 1, 1,.

  The content transmission device 1 reads content from the content storage device 3 based on a request from the content reception device 5 and transmits the content to the content reception device 5. Here, the content transmission device 1 receives a synchronization packet from the content reception device 5 as a content transmission request.

  This synchronization packet includes the time code (basic data specifying information) of the content. Here, the time code is time information attached to frame data (basic data) of content in units of frames. There is SMPTE12M-1999 “Television, Audio and Film-Time and Control Code” as a standard of this time code, and it will be described here as using it. However, in the present invention, content can be identified in units of frames. If there is, the structure of the time code is not limited to this.

  Then, the content transmission device 1 reads frame data corresponding to the time code included in the synchronization packet from the content storage device 3, divides the frame data into blocks, and transmits the data to the content reception device 5 as data packets. Here, a case where the content transmission / reception system S includes a plurality of content transmission devices 1, 1,... Will be described, but at least one content transmission device 1 of the present invention is provided via the network N in the content transmission system S. It only has to be connected.

  The content storage device 3 stores content such as video and audio, and is a general storage unit such as a hard disk. The content accumulated here is read for each frame data by the content transmission device 1.

  The content receiving device 5 transmits a synchronization packet serving as a content transmission request to the content transmitting device 1, receives the data packet transmitted from the content transmitting device 1, reconfigures the frame data, and outputs the content. is there. Here, a plurality of content receiving devices 5, 5,... Are connected to the network N to constitute a content reproduction device 4 that outputs a plurality of contents in synchronization. The same frame clock (basic clock) is input to the content receivers 5, 5,. Here, a 29.97 Hz clock signal, which is the frame frequency of the video signal, is input as the frame clock. In addition, a reproduction delay amount (delay amount) to be described later is input in advance to the content receiving devices 5, 5,.

  Furthermore, a time code serving as a content reproduction request is input to each of the content receiving devices 5. Here, when the content receiving device 5 reproduces the content at a normal speed, for example, each of the content receiving devices 5, 5,... Has a time code value increased by one frame for each frame clock. Entered. In addition, when it is desired to reproduce the content at twice the speed, a time code value increased by two frames every frame clock may be input.

  Here, the network N is assumed to be unreliable, for example, UDP / IP (User Datagram Protocol / Internet Protocol) as the transfer protocol of the network N in which the data packet flows, and the transfer of the network N in which the synchronization packet flows. As a protocol, reliable, for example, TCP / IP (Transmission Control Protocol / Internet Protocol) is assumed. That is, there is a possibility that the data packet does not reach the content receiving device 5 due to packet loss or the like in the network N. On the other hand, it is assumed that the synchronous packet has no packet loss, or even if there is a packet loss, the synchronous packet surely reaches the content transmitting apparatus 1 by a retransmission control technique, an error correction technique, or the like. .

(Usage example of content transmission / reception system)
Next, a usage example of the content transmission / reception system S will be described with reference to FIG. FIG. 2 is a schematic diagram schematically showing a usage example of a content transmission / reception system including a content transmission device and a content reception device according to the present invention. Here, the content transmission / reception system S is stored in the content storage device 3A, the video content transmitted by the content transmission device 1A is received by the content reception device 5A, output to the video monitor V, and stored in the content storage device 3B. Then, the audio content transmitted by the content transmitting device 1B is received by the content receiving device 5B, and is output to the audio monitor A in synchronization with the video content output to the video monitor V. The content transmission devices 1A and 1B have the same configuration as the content transmission device 1 in FIG. 1, and the content storage devices 3A and 3B have the same configuration as the content storage device 3 in FIG. Further, the content receiving devices 5A and 5B have the same configuration as the content receiving device 5 of FIG.

  Here, the same frame clock, time code, and the same reproduction delay amount are input to the content receiving devices 5A and 5B. Here, the time code is input by incrementing by one for each frame clock. Then, the content receiving devices 5A and 5B simultaneously output video frame data and audio frame data corresponding to the same time code. That is, even if the content transmitting devices 1A and 1B are connected to the networks N of different RTTs, the content receiving devices 5A and 5B can output frame data synchronized at the time code level.

  Hereinafter, the configuration of the content transmission device 1 and the content reception device 5 of the present invention will be described in detail with reference to FIG. FIG. 3 is a block diagram showing the configuration of the content transmission device and content reception device according to the present invention. Note that FIG. 3 shows a set of the content transmission device 1 and the content reception device 5.

First, the configuration of the content transmission device 1 will be described with reference to FIG.
(Configuration of content transmission device)
The content transmission apparatus 1 includes a frame input unit 11, a synchronous reception unit 12, a packet transmission unit 13, and a communication transmission / reception unit 14.

  The frame input means (basic data input means) 11 reads the frame data of the content corresponding to the time code input from the synchronous receiving means 12 from the content storage device 3 (see FIG. 1) connected to the outside. . The frame data input here is input to the packet transmission means 13.

  The synchronous receiving means (synchronous packet receiving means) 12 receives the synchronous packet transmitted from the content receiving device 5 via the communication transmitting / receiving means 14. Here, the synchronization receiving unit 12 receives a synchronization packet that is a transmission request for content frame data from the content receiving device 5. This synchronization packet includes time code information. When this synchronization packet is input, the synchronization receiving means 12 outputs this time code information to the frame input means 11, and further the frame input means 11. Is output to the packet transmission means 13 as a command to transmit the frame data input from.

  The packet transmission unit 13 divides the frame data input from the frame input unit 11 into transmission packets (data packets) in the network N, and the communication transmission / reception unit 14 based on the transmission request signal input from the synchronous reception unit 12. Is transmitted to the content receiver 5 via

  Here, RTP (Real-time Transport Protocol) defined in RFC 1889, 1996 “RTP: A Transport Protocol for Real-Time Applications” as a standard of the structure of the data packet generated by the packet transmission means 13 is used here. However, in the present invention, the packet structure is not limited to this. Here, RTP is a packet structure standard for transmitting multimedia data by UDP / IP.

  The communication transmitting / receiving means 14 transmits / receives communication data via the network N. For example, the communication transmission / reception means 14 transmits / receives communication data using a UDP / IP or TCP / IP communication protocol.

Next, the configuration of the content receiving device 5 will be described.
(Configuration of content receiving device)
The content reception device 5 includes a communication transmission / reception unit 51, a packet reception unit 52, a frame generation unit 53, a frame storage unit 54, a synchronization transmission unit 55, a synchronization generation unit 56, a frame output unit 57, and a reproduction signal. Generating means 58.

  The communication transmission / reception means 51 transmits / receives communication data via the network N. For example, the communication transmission / reception means 51 transmits / receives communication data using a UDP / IP or TCP / IP communication protocol.

  The packet receiving unit 52 receives a data packet transmitted from the content transmitting apparatus 1 via the communication transmitting / receiving unit 51. Here, the data packet obtained by dividing the frame data of the content is input from the content transmitting device 1 to the packet receiving unit 52. The data packet input here is output to the frame generation means 53.

  The frame generation means (basic data reconstruction means) 53 reconstructs the content frame data from the data packet input from the packet reception means 52. The reconstructed frame data is stored in the frame storage means 54.

  The frame storage means (basic data storage means, basic data storage device) 54 stores the frame data reconstructed by the frame generation means 53, and is, for example, a FIFO (First-In First-Out) by a frame memory. . The frame data stored here is read by the frame output means 57.

  The synchronization transmission means (synchronization packet transmission means) 55 transmits the synchronization packet input from the synchronization generation means 56 to the content transmission apparatus 1 via the communication transmission / reception means 51 in synchronization with the frame clock input from the outside. Is.

  The synchronization generation means 56 generates a synchronization packet in which a time code input from the outside is used as a packet for transmission in the network N. The synchronization packet generated here is output to the synchronization transmission means 55.

  Here, the synchronization packet generated by the synchronization generation means 56 is data of only the time code, but in the present invention, the synchronization packet is not limited to this. For example, in the case of applying to the method of synchronizing system level of contents stored in different servers (content transmitting apparatus 1 and content storing apparatus 3) via network N in Japanese Patent Application No. 2005-148185, a response packet May be a synchronization packet, and time code data may be superimposed on the header portion in the response packet. In the method of Japanese Patent Application No. 2005-148185, the content receiving device 5 transmits a response packet to the content transmitting device 1 based on the frame clock, and the content transmitting device 1 synchronizes with the response packet to transmit the content frame. By transmitting data to the content receiving device 5, content frame data is transmitted and received in synchronization with the frame clock of the content receiving device 5.

  The frame output means (basic data output means) 57 sequentially reads out the frame data from the frame storage means 54 based on the reproduction request signal (delay signal) input from the reproduction signal generation means 58 and outputs it to the outside. .

  The reproduction signal generation means (delay signal generation means) 58 outputs a reproduction request signal serving as a frame data output command to the frame output means 57 based on the frame clock and the reproduction delay amount inputted from the outside. is there.

  Hereinafter, the reproduction request signal and the reproduction delay amount will be described with reference to FIGS. 4 and 5 (refer to FIG. 3 as appropriate). FIG. 4 is a graph showing the relationship between the voltage and time of the frame clock and the reproduction delay amount. FIG. 5 is a schematic diagram schematically showing an example of frame data stored in the frame storage means of a plurality of content receiving apparatuses.

  As shown in FIG. 4, the reproduction request signal C2 is a signal obtained by delaying the frame clock C1 by a predetermined reproduction delay amount D. Here, it is assumed that the reproduction delay amount is set according to the number of frames. In FIG. 4, three frames are set as the reproduction delay amount, and the reproduction signal generator 58 delays the frame clock C1 by three frames. The case where the signal C2 is generated is shown. And this reproduction delay amount inputs the same value to all of the plurality of content receiving devices 5, 5,... (See FIG. 1) connected to the network N.

  Next, referring to FIG. 5, specific examples of the reproduction request signal and the frame data F, F,... Stored in the frame storage means 54A, 54B,. Will be described. The frame storage means 54A, 54B,..., 54N have the same configuration as the frame storage means 54 in FIG.

  Here, first, it is assumed that time codes TCA1, TCB1,..., TCN1 are input to content receiving apparatuses 5, 5,. Then, each of the content reception devices 5, 5,... Transmits the synchronization signal of each time code TCA1, TCB1,..., TCN1 to the corresponding content transmission device 1, 1,. The content transmission devices 1, 1,... Transmit frame data corresponding to the time codes TCA1, TCB1,..., TCN1, respectively, as data packets, and the content reception devices 5, 5,. The data packets are received from 1, 1,..., The frame data is reconstructed by the respective frame generation means 53, and the frame storage means 54A, 54B,..., 54N are respectively converted into the time codes TCA1, TCB1,. Corresponding frame data F, F,... Are stored.

  Subsequently, when the next time code TCA2, TCB2,..., TCN2 is input to each of the content reception devices 5, 5,..., The content transmission devices 1, 1,. Repeat the same operation. In this way, a plurality of frame data F, F,... Is stored in each of the frame storage means 54A, 54B,..., 54N, and for example, as shown in FIG. The frame data F, F, F, F of TCA4 are stored in the frame storage means 54B, the frame data F, F of time code TCB1, TCB2, and the frame data F, F of time codes TCN1-TCN3 are stored in the frame storage means 54N. , F is stored.

  Here, data packets are supplied to the respective content receiving devices 5, 5,... Based on the synchronization packet, and frames are sequentially transmitted from the respective frame storage means 54A, 54B,. Data F, F,... Are output. Therefore, each frame storage means 54A, 54B,..., 54N stores frame data F for (reproduction delay amount−network delay amount). Here, since the reproduction request signal becomes the same as the frame clock when the reproduction delay amount has elapsed, the frame data F, F,... 54N in the frame storage means 54A, 54B,. Is output. In this way, by setting a generation delay amount that is equal to or greater than the network delay amount in advance, the network delay amount is adjusted by the frame storage means 54A, 54B,..., 54N, and synchronized by the frame output means 57 at the time code level. Frame data F, F,... Can be output.

  For example, in FIG. 5, the frame storage means 54A stores four frame data F, F, F, and F, and the frame storage means 54B stores two frame data F and F. That is, the content receiving device 5 having the frame storage means 54A has a smaller network delay amount by two frames than the content receiving device 5 having the frame storage means 54B, and has received frame data of a time code two frames ahead. .

  However, from the frame storage means 54A and the frame storage means 54B, based on the reproduction request signal, the frame data F corresponding to the time code TCA1 and the frame data F corresponding to the time code TCB1 by the corresponding frame output means 57, respectively. Is output. In this way, even if the frame data received by the content receivers 5, 5,... Is not synchronized at the time code level due to the delay in the network N, the content receivers 5, 5,. Frame data synchronized by level is output.

  As described above, the content transmitting / receiving system S (see FIG. 1) receives the content frame data transmitted via the network N by the content transmitting devices 1, 1,... By the content receiving devices 5, 5,. Can be output. In addition, even when the network delay amounts of the frame data transmitted from the content transmission devices 1, 1,... Are different from each other, the content reception devices 5, 5,. For example, when the content transmission / reception system S has only one content transmission device (not shown), the network delay amount of the frame data transmitted from the content transmission device to the plurality of content reception devices 5, 5,. Even if they are different from each other, the content receiving devices 5, 5,... Can be synchronized and output at the time code level.

  The content transmitting apparatus 1 and the content receiving apparatus 5 can also realize each unit as a function program in a computer, and can also operate the function transmitting program and the content receiving program by combining the function programs. Is possible.

[Operation of content transmission device]
Next, with reference to FIG. 6 (refer to FIG. 3 as appropriate), a frame data transmission operation in which the content transmission device 1 according to the present invention transmits content frame data to the content reception device 5 will be described. FIG. 6 is a flowchart showing an operation in which the content transmitting apparatus according to the present invention transmits content frame data.

  First, the content transmission device 1 determines whether the synchronization reception unit 12 has received the synchronization packet from the content reception device 5 via the communication transmission / reception unit 14 (step S11). If it has not been received (No in step S11), the process returns to step S11 to determine whether or not the synchronization packet has been received again. If received (Yes in step S11), the content transmission apparatus 1 generates a data packet transmission request signal by the synchronous reception unit 12 and outputs the data packet transmission request signal to the packet transmission unit 13 (step S12).

  Subsequently, the content transmitting apparatus 1 acquires the time code included in the synchronous packet received in step S11 by the synchronous receiving unit 12, and outputs the time code to the frame input unit 11 (step S13). Furthermore, the content transmission apparatus 1 inputs frame data corresponding to the time code acquired in step S13 from the content storage apparatus 3 by the frame input unit 11 (step S14).

  Then, the content transmission apparatus 1 generates a data packet by dividing the frame data input in step S14 by the packet transmission unit 13 (step S15). Further, the content transmitting apparatus 1 transmits the data packet generated in step S15 by the packet transmitting unit 13 to the content receiving apparatus 5 via the communication transmitting / receiving unit 14 (step S16), and returns to step S11 to continue to the next step. The operation after the operation of determining whether the synchronization packet is received is performed.

[Operation of content receiving device]
Next, with reference to FIGS. 7 to 9 (refer to FIG. 3 as appropriate), the operation of the content receiving apparatus 5 in the present invention will be described.

(Frame data reception operation of content receiving device)
First, referring to FIG. 7 (refer to FIG. 3 as appropriate), a frame data receiving operation in which the content receiving device 5 according to the present invention receives frame data of content from the content transmitting device 1 will be described. FIG. 7 is a flowchart showing an operation in which the content receiving apparatus of the present invention receives content frame data.

  First, the content reception device 5 determines whether the packet reception unit 52 has received a data packet from the content transmission device 1 via the communication transmission / reception unit 51 (step S51). If it has not been received (No in step S51), the process returns to step S51 to determine whether or not the data packet has been received again.

  If received (Yes in step S51; packet receiving step), the content receiving device 5 reconstructs the frame data from the data packet received in step S51 by the frame generating means 53 (step S52; basic data). Reconfiguration step). Further, the content receiving device 5 stores the frame data reconstructed in step S52 in the frame storage means 54 (step S53; basic data storage step), and returns to step S51 to determine whether the data packet has been received again. Perform the following operations.

(Frame data output operation of content receiver)
Next, with reference to FIG. 8 (refer to FIG. 3 as appropriate), a frame data output operation in which the content receiving device 5 according to the present invention outputs content frame data will be described. FIG. 8 is a flowchart showing an operation in which the content receiving apparatus of the present invention outputs content frame data.

  First, the content receiving apparatus 5 determines whether or not time code information has been input from the outside by the synchronization generation means 56 (step S61). If it has not been input (No in step S61), the process returns to step S61 to determine whether the time code has been input again. When the content is input (Yes in step S61), the content reception device 5 generates a synchronization packet including the time code input in step S61 by the synchronization generation means 56 (step S62).

  Furthermore, the content reception device 5 transmits the synchronization packet generated in step S62 to the content transmission device 1 by the synchronization transmission means 55 in synchronization with the frame clock input from the outside. At the same time, the content receiving apparatus 5 synchronizes with the reproduction request signal delayed by the reproduction delay amount generated by the reproduction signal generating means 58, and the time indicated by the time code input in step S61 by the frame output means 57. Thus, the frame data corresponding to the time code of the time before the frame indicated by the reproduction delay amount is read from the frame storage means 54 and output (step S63). Then, the content receiving device 5 returns to step S61 and performs the operation after the operation of determining whether the time code is input again.

(Frame data reception output operation of multiple content reception devices)
Further, referring to FIG. 9 (refer to FIGS. 2, 3, 7 and 8 as appropriate), the plurality of content receiving apparatuses 5A and 5B according to the present invention receive the frame data and output them synchronously at the time code level. The frame data reception / output operation will be described. FIG. 9 is a flowchart showing an operation in which a plurality of content receiving apparatuses according to the present invention receive content frame data and output them synchronously.

  Note that, here, as shown in FIG. 2, the content receiving devices 5A and 5B are respectively connected to the network N by taking an example in which two content transmitting devices 1A and 1B and two content receiving devices 5A and 5B are connected. The operation of receiving one frame data and outputting the frame data synchronously at the time code level will be described. Here, the case where the network delay amount NDA of the content receiving device 5A is shorter than the network delay amount NDB of the content receiving device 5B will be described as an example.

<Synchronous packet transmission step>
First, the content receiving device 5A and the content receiving device 5B each generate a synchronization packet including information on a time code input from the outside by the synchronization generating means 56 (corresponding to steps S101 and S61 and S62 in FIG. 8) . Subsequently, the content reception device 5A and the content reception device 5B transmit the synchronization packet generated in step S101 to the content transmission device 1 by the synchronous transmission means 55 in synchronization with the frame clock input from the outside (see FIG. Step S102).

  Then, the content reception device 5A receives the data packet of the frame data corresponding to the time code included in the synchronization packet transmitted from the content reception device 5A in step S102 by the packet reception unit 52 (in step S51 of FIG. 7). Equivalent; packet reception step), frame data is reconstructed from the data packet by the frame generation means 53 (equivalent to step S52 in FIG. 7; basic data reconstruction step), and the frame data is stored in the frame storage means 54 ( Equivalent to step S53 in FIG. 7; basic data storage step) (step S103). Here, the time required from step S102 to step S103 is the network delay amount NDA of the content receiving device 5A.

  Subsequently, the content reception device 5B receives the data packet of the frame data corresponding to the time code included in the synchronization packet transmitted from the content reception device 5B in step S102 by the packet reception unit 52, and the frame generation unit 53 Frame data is reconstructed from this data packet, and the frame data is stored in the frame storage means 54 (step S104). Here, the time required from step S102 to step S104 is the network delay amount NDB of the content receiving device 5B.

  Further, each of the content receiving device 5A and the content receiving device 5B synchronizes with the playback request signal obtained by delaying the frame clock input in step S102 by the playback signal generating means 58 by a playback delay amount D set in advance. In step S103 and step S104, the frame data stored in the frame storage unit 54 is output to the outside by the frame output unit 57 (step S105).

  By the above operation, the content receiving device 5A and the content receiving device 5B can output the frame data in synchronization with the time code level even when the network delay amounts NDA and NDB of the received frame data are different.

It is the block diagram which showed the structure of the content transmission / reception system provided with the content transmitter in this invention, and a content receiver. It is the schematic diagram which showed typically the usage example of the content transmission / reception system provided with the content transmission apparatus and content reception apparatus in this invention. It is the block diagram which showed the structure of the content transmitter in this invention, and a content receiver. 6 is a graph showing the relationship between the voltage and time of the frame clock input to the content receiving apparatus according to the present invention and the reproduction delay amount generated. It is the schematic diagram which showed typically the example of the frame data memorize | stored in the frame memory | storage means of the some content receiver in this invention. It is the flowchart which showed the operation | movement which the content transmission device in this invention transmits the frame data of a content. It is the flowchart which showed the operation | movement which the content receiver in this invention receives the frame data of a content. 6 is a flowchart showing an operation of outputting content frame data by the content receiving apparatus according to the present invention. It is the flowchart which showed the operation | movement which the some content receiver in this invention receives the frame data of a content, and outputs synchronously.

Explanation of symbols

1 content transmission device 11 frame input means (basic data input means)
12 Synchronous receiving means (Synchronous packet receiving means)
13 Packet transmission means 5 Content reception device 52 Packet reception means 53 Frame generation means (basic data reconstruction means)
54 Frame storage means (basic data storage means, basic data storage device)
55 Synchronous transmission means (Synchronous packet transmission means)
57 Frame output means (basic data output means)
58 Playback signal generating means (delayed signal generating means)

Claims (4)

Receiving the data packet from a content transmitting apparatus that is connected to a plurality of networks and transmits the basic data of content data configured in units of basic data of a predetermined length via the network in units of data packets for network transmission; A content receiving device for reconfiguring the content data in units of the basic data,
Synchronization packet transmitting means for transmitting a synchronization packet including basic data specifying information for specifying the basic data to the content transmission device in synchronization with a basic clock indicating a timing for reproducing the basic data;
Packet receiving means for receiving a data packet of the basic data corresponding to the basic data specifying information of the synchronous packet transmitted by the synchronous packet transmitting means, from the content transmitting device;
Basic data reconstructing means for reconstructing the basic data from the data packet received by the packet receiving means;
Basic data storage means for storing basic data reconstructed by the basic data reconstruction means;
A delay signal generating means for generating a delay signal that is set in advance from the basic clock and delayed by the same delay amount as other content receiving devices connected to the network ;
Basic data output means for reading out and outputting the basic data corresponding to the basic data specifying information from the basic data storage means based on the delay signal generated by the delay signal generating means;
A content receiving apparatus comprising: The basic data corresponding to the basic data specifying information for specifying the basic data of the content data that is connected to the network and configured with basic data of a predetermined length as a unit is transmitted via the network in units of data packets for network transmission. A content transmitting device for transmitting to the content receiving device according to claim 1,
Synchronization packet receiving means for receiving a synchronization packet including the basic data specifying information from the content receiving device;
Basic data input means for inputting the basic data corresponding to the basic data specifying information included in the synchronous packet received by the synchronous packet receiving means;
Packet transmitting means for dividing the basic data input by the basic data input means, generating the data packet and transmitting it to the content receiving device;
A content transmission apparatus comprising: There is a basic data storage device for storing the basic data from a content transmitting device that transmits the basic data of content data configured in units of basic data of a predetermined length via the network in units of data packets for network transmission. A basic data synchronization method for receiving the data packet by a plurality of content receiving devices connected to a network, reconfiguring and outputting the content data in units of the basic data,
A synchronization packet transmission step of transmitting a synchronization packet including basic data specifying information for specifying the basic data to the content transmission device in synchronization with a basic clock indicating a timing for reproducing the basic data;
A packet receiving step of receiving a data packet of the basic data corresponding to the basic data specifying information of the synchronous packet transmitted in the synchronous packet transmitting step from the content transmitting device;
A basic data reconstruction step of reconstructing the basic data from the data packet received in the packet reception step;
A basic data storage step of storing the basic data reconstructed in the basic data reconstruction step in the basic data storage device;
Corresponding to the basic data specifying information from the basic data storage device based on a delay signal that is set in advance from the basic clock and delayed by the same delay amount as other content receiving devices connected to the network A basic data output step for reading and outputting the basic data;
A basic data synchronization method comprising: From the content transmission device that transmits the basic data of content data configured in units of basic data of a predetermined length via the network in units of data packets for network transmission, the content data is received from the content transmission device. Reconfiguring in basic data units, storing the basic data in a basic data storage device that stores the basic data, and reading and outputting the basic data storage device from the computer,
A synchronization packet transmitting means for transmitting a synchronization packet including basic data specifying information for specifying the basic data to the content transmitting device in synchronization with a basic clock indicating a timing for reproducing the basic data;
Packet receiving means for receiving a data packet of the basic data corresponding to the basic data specifying information of the synchronous packet transmitted by the synchronous packet transmitting means from the content transmitting device;
Basic data reconstruction means for reconstructing the basic data from the data packet received by the packet receiving means and storing the basic data in the basic data storage device;
A delay signal generating unit configured to generate a delay signal that is delayed from the basic clock by the same delay amount as that of another content receiving device connected to the network ,
Basic data output means for reading out and outputting the basic data corresponding to the basic data specifying information from the basic data storage device based on the delay signal generated by the delay signal generating means;
A content receiving program that is made to function as:

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