JP2012019270A - Content data receiving/reproducing device, content data transmitting/receiving system and content data transmitting/receiving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a content data receiving/reproducing device, a content data transmitting/receiving system and its method which can remove commercial data in real time which is included in content data distributed by streaming.SOLUTION: The content data receiving/reproducing device sequentially receives packets distributed by the streaming, and when discriminates by receiving a single packet that identification data included in a header of the single packet indicates that a content of one piece of the content data included in the single packet is a commercial, deletes the one piece of the content data before or after storing in a buffer.

Description

  The present invention relates to a content data reception / playback apparatus, a content data transmission / reception system, and a content data transmission / reception method for receiving content distributed by a stream type VOD (Video On Demand) method.

  2. Description of the Related Art Conventionally, an apparatus such as a recorder with a built-in hard disk that reproduces only a main part by removing a so-called commercial part in a broadcast program is known. For example, Patent Document 1 discloses a digital recording / reproducing apparatus that performs such processing. The apparatus receives data of the entire broadcast program and records it on a recording medium such as a hard disk. Next, so-called scene change detection is performed on the data recorded on the recording medium, and a portion where the interval between scene changes is, for example, 15 seconds or 30 seconds is determined as a commercial portion. Only the main part is reproduced based on the determination result.

JP 2005-175710 A

  By the way, a video on demand method (hereinafter referred to as a VOD method) for streaming content composed of video, audio and the like in response to a viewer's request is known. There is a problem that the commercial portion of the content streamed by the VOD method cannot be removed. Since this apparatus is configured to once record the data of the entire broadcast program on a recording medium and then detect a scene change, the commercial portion included in the stream-distributed content cannot be removed in real time.

  The present invention has been made in view of the above-described problems, and is a content data reception / playback apparatus, content data transmission / reception system, and content that can remove commercial data included in stream-distributed content data in real time. An object is to provide a data transmission / reception method.

  A content data reception / playback apparatus according to the present invention includes a receiving unit that sequentially receives packets distributed from a server via a communication network, and a storage unit that sequentially stores content data included in the packets received by the receiving unit. A content data reception / playback device that sequentially retrieves and plays back the content data stored in the storage unit, and when the reception unit receives a single packet, the header of the single packet Before or after the storage of the one content data in the storage unit when it is determined that the content of the one content data included in the one packet indicates commercial content A data deletion unit for deleting one piece of content data is included.

  A content data transmission / reception system according to the present invention includes a server that transmits a packet including content data via a communication network in response to a content request, and a packet that is stream-transmitted by the server via the communication network. A content data receiving / reproducing system that sequentially accumulates content data contained in the packet in an accumulator and sequentially retrieves and reproduces the content data accumulated in the accumulator; The reception / playback apparatus indicates that when the reception unit receives one packet, the content of one content data included in the one packet includes identification data included in a header of the one packet. If it is determined that Characterized in that it comprises a data deleting unit that deletes the one content data in storage before or after the one content data.

  A content data transmission / reception method according to the present invention includes a stream transmission step of transmitting packets including content data via a communication network, and a reception step of sequentially receiving packets transmitted at the stream transmission step via the communication network. A content data transmission / reception method comprising: a storage step of storing content data included in the packet received in the reception step; and a playback step of sequentially extracting and playing back the content data stored in the storage step, When it is determined in the reception step that the identification data included in the header of the one packet indicates that the content of the one content data included in the one packet is a commercial when one packet is received In Characterized in that it comprises a data deleting step for deleting the one of the content data after accumulation before or the one content data in the serial storage step.

  According to the content data reception / playback apparatus, content data transmission / reception system, and content data transmission / reception method of the present invention, it is possible to remove commercial data included in stream-distributed content data in real time.

It is a block diagram which shows the structure of the content data receiving / reproducing apparatus of a present Example with a VOD server, a communication network, an output part, and a remote control. It is a figure which shows the structure of the packet transmitted to a content data receiving / reproducing apparatus from a VOD server. It is a figure which shows the GOP header of the packet for commercial data. It is a figure which shows the GOP header of the packet for main data. It is a flowchart which shows a content reception process routine. It is a sequence diagram which shows the content transmission / reception process between a content data receiving / reproducing apparatus (STB) and a VOD server. (A) is a figure which shows the buffer part at the time of transmission / reception at normal speed, and the data of a main part and commercial (CM). (B) is a diagram showing a buffer unit and these data at the time of CM deletion. (C) is a diagram showing the buffer section and the main part data when the buffer accumulation amount falls below a predetermined threshold data amount. (D) is a diagram showing the buffer section and the main part data when the buffer accumulation amount exceeds a predetermined threshold data amount.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing the configuration of the content data receiving / reproducing apparatus 10 of this embodiment together with the VOD server 20, the communication network 30, the output unit 40, and the remote controller 50. In response to a content reception instruction issued by the user from the remote controller 50, the content data reception / playback apparatus 10 receives content data such as video from the VOD server 20 via a communication network 30 such as the Internet in a packet stream, and the content For example, a receiving device such as a set top box (STB) that reproduces and outputs video and audio on the output unit 40 such as a liquid crystal display based on the data. Hereinafter, the content data receiving / reproducing apparatus 10 is referred to as STB10. Hereinafter, a system including the STB 10, the VOD server 20, the communication network 30, the output unit 40, and the remote controller 50 is referred to as a content data transmission / reception system 1.

  The STB 10 includes an operation signal receiving unit 11, a content request transmitting unit 12, a content receiving unit 13, a buffer unit 14, a CM data deleting unit 15, a transmission speed change request transmitting unit 16, a content reproducing unit 17, STB control unit 18.

  The operation signal receiving unit 11 is a receiving device such as an infrared receiving module that receives an operation signal wirelessly transmitted from the remote controller 50 by a user operation. The operation signal is, for example, a signal requesting content such as video.

  The content request transmission unit 12 transmits a content request to the VOD server 20 via the communication network 30 in response to the content request signal received by the operation signal reception unit 11.

  The content receiver 13 receives content data transmitted from the VOD server 20 in response to the content request via the communication network 30. The content data is streamed from the VOD server 20 by packets. There are two types of packets, one that includes content main data (hereinafter referred to as main packet) and one that includes so-called commercial data (hereinafter referred to as CM packet).

  The buffer unit 14 sequentially accumulates data (hereinafter referred to as main program data) included in the main program packet received by the content receiving unit 13. Further, the buffer unit 14 temporarily accumulates data included in the CM packet received by the content receiving unit 13 (hereinafter referred to as commercial data or CM data) until the data is deleted by the CM data deleting unit 15. You can also. The buffer unit 14 is a storage medium such as a RAM or a hard disk, and can store MPEG2 standard packet data for about 10 to 20 minutes, for example.

  When the content receiving unit 13 receives a packet, the CM data deleting unit 15 determines that the identification data included in the GOP header of the packet indicates that the content of the content data included in the packet is commercial. In such a case, the content data temporarily stored in the buffer unit 14 is deleted.

  When the content receiving unit 13 receives a packet, the CM data deleting unit 15 indicates that the identification data included in the GOP header of the packet includes the content of the content data included in the packet. Can be deleted without accumulating the content data in the buffer unit 14.

  The CM data deletion unit 15 may delete one piece of content data each time the determination is made, or may delete a plurality of pieces of content data collectively after a plurality of determinations.

  The transmission rate change request transmission unit (hereinafter referred to as a change request transmission unit) 16 determines the transmission rate of the content data when determining that the amount of data stored in the buffer unit 14 is below a predetermined threshold data amount. A request to increase (hereinafter referred to as a transmission speed increase request) is transmitted to the VOD server 20. The threshold data amount is, for example, about 20% of the storable capacity of the buffer unit 14. The transmission speed increase request is a request for transmission at a speed about 1.1 to 2 times that of normal transmission, for example. If the content data transmission amount of the VOD server 20 at normal time is, for example, 10 Mbps, the content data transmission at, for example, 13 Mbps is requested in the transmission speed increase request.

  The change request transmission unit 16 returns the transmission rate of the content data to normal when it is determined that the amount of data accumulated in the buffer unit 14 exceeds a predetermined threshold data amount after the transmission rate increase request. A request (hereinafter referred to as a transmission speed normalization request) is transmitted to the VOD server 20. Similarly, the threshold data amount is, for example, about 20% of the storable capacity of the buffer unit 14. If the content data transmission amount of the VOD server 20 at normal time is, for example, 10 Mbps, the content data transmission at 10 Mbps, for example, is requested in the transmission speed normalization request.

  The content playback unit 17 extracts the main data stored in the buffer unit 14 in the order in which they are stored, and sequentially plays back video and the like based on the extracted main data. The amount of main data per unit time that the content reproduction unit 17 retrieves from the buffer unit 14 is the same amount or almost the same amount as the amount of content data that the content reception unit 13 receives from the VOD server 20 per unit time in normal times. is there.

  The STB control unit 18 is a processing device such as a CPU that controls each functional block included in the STB 10. Each of the above functional blocks can be appropriately configured by, for example, hardware such as a microprocessor and a memory, and software for causing them to function.

  The VOD server 20 is a server that performs stream distribution of content data using packets in response to a content distribution request from the STB 10. The VOD server 20 includes a content storage unit 21, a content request reception unit 22, a content transmission unit 23, a transmission speed change request reception unit 24, a transmission speed control unit 25, and a VOD control unit 26.

  The content storage unit 21 is a storage medium such as a hard disk that stores content such as video.

  The content request receiving unit 22 receives the content request transmitted from the content request transmitting unit 12 of the STB 10.

  In response to the content request received by the content request reception unit 22, the content transmission unit 23 transmits content data corresponding to the content indicated by the content request via the communication network 30. The content transmission unit 23 transmits the content data at the transmission speed notified from the transmission speed control unit 25.

  A transmission rate change request receiving unit (hereinafter simply referred to as a change request receiving unit) 24 receives a transmission rate increase request and a transmission rate normalization request transmitted from the change request transmission unit 16 of the STB 10 via the communication network 30. .

  The transmission rate control unit 25 notifies the content transmission unit 23 of a transmission rate obtained by increasing the transmission rate of the content data by a predetermined amount in response to the transmission rate increase request received by the change request receiving unit 24. . Further, the transmission rate control unit 25 notifies the content transmission unit 23 of the transmission rate obtained by returning the transmission rate of the content data to the normal time in response to the transmission rate normalization request received by the change request receiving unit 24.

  The VOD control unit 26 is a processing device such as a CPU that controls each functional block included in the VOD server 20. Each of the above functional blocks can be appropriately configured by, for example, hardware such as a microprocessor and a memory, and software for causing them to function.

  The communication network 30 is a communication network such as the Internet, for example. The output unit 40 includes a display device such as a liquid crystal display and an audio speaker. The remote controller 50 is a remote control terminal that accepts an input such as a content request by a user and wirelessly transmits an operation signal corresponding to the input to the operation signal receiving unit 11 of the STB 10 using, for example, infrared rays.

  FIG. 2 is a diagram illustrating a configuration of a packet transmitted from the VOD server 20 to the STB 10. The packet has a GOP (Group Of Pictures) structure configured according to the format of the MPEG2 standard. One packet having the GOP structure includes data of 500 milliseconds (15 frames). A packet consists of frame data and a GOP header. The frame data is main data or CM data, and includes an I frame, a P frame, and a B frame. The total number of frames in one packet is 15. The GOP header is composed of various information related to the packet.

  FIG. 3 is a diagram illustrating a GOP header of a CM packet. The GOP header of the CM packet includes a user data start code and user data. The user data start code is a unique code such as 0x000001B2 indicating that the subsequent data is user data. The user data is unique identification data such as 0x01 indicating that the packet is a CM packet. The user data start code is 32-bit data, and the user data is 8-bit data. The GOP start code (eg, 0x000001B8), time code, closed GOP, broken link, and extension data are standard data of the GOP standard, and are 32-bit, 25-bit, 1-bit, 1-bit, and 5-bit data, respectively.

  FIG. 4 is a diagram showing the GOP header of the main packet. The GOP header of the main packet includes a GOP start code, a time code, a closed GOP, a broken link, and extension data, but does not include a user data start code and user data.

  FIG. 5 is a flowchart showing a content reception processing routine. FIG. 6 is a sequence diagram showing content transmission / reception processing between the STB 10 and the VOD server 20. Hereinafter, content reception processing by the STB 10 will be described with reference to FIGS. 5 and 6.

  First, the operation signal receiving unit 11 of the STB 10 receives a content request signal wirelessly transmitted from the remote controller 50 by a user operation (steps S101 and S201). Next, the content request transmission unit 12 transmits a content request to the VOD server 20 via the communication network 30 in accordance with the content request signal received by the operation signal reception unit 11 (steps S102 and S202).

  The content request receiving unit 22 of the VOD server 20 receives the content request transmitted from the content request transmitting unit 12 (step S203). In response to the content request received by the content request receiving unit 22, the content transmission unit 23 stream-distributes content data corresponding to the content indicated by the content request by a packet (step S204). The content transmission unit 23 transmits content data at a predetermined normal speed.

  The content receiver 13 of the STB 10 receives the packet transmitted from the content transmitter 23 via the communication network 30 (steps S103 and S205). The buffer unit 14 sequentially accumulates the main data included in the main packet received by the content receiving unit 13 (step S103). The buffer unit 14 can also temporarily store the CM data included in the CM packet received by the content receiving unit 13 until the CM data deleting unit 15 deletes the CM data (step S103).

  FIG. 7A is a diagram showing the buffer unit 14, main data, and CM data at the time of transmission / reception at a normal speed. The main part data is shown as “main part” and the CM data is shown as “CM” (the same applies to FIGS. 7B to 7D). The main part data is stored in the buffer unit 14 in the order of reception. The main data stored in the buffer unit 14 is taken out and reproduced by the content reproduction unit 17 (FIG. 1) in the order of accumulation. When the content receiving unit 13 (FIG. 1) receives CM data, this is also temporarily stored in the buffer unit 14.

  When the content receiving unit 13 receives a packet, the CM data deleting unit 15 checks the contents of the user data if the user data start code is included in the GOP header of the packet. Then, if the CM data deleting unit 15 determines that the user data is specific identification data such as 0x01, for example, the CM data deleting unit 15 determines that the received packet is a CM packet (step S104), and stores it in the buffer unit 14. Of the temporarily stored data, the CM data corresponding to the CM packet is deleted (step S105). In addition, each of the STB 10 and the VOD server is set in advance to use, for example, 0x01 as unique identification data indicating that the packet is a CM packet (the content of the content data included in the packet is commercial). ing.

  In addition, the CM data deletion unit 15 includes the identification data included in the GOP header of the packet when the content reception unit 13 receives the packet, for example, by including specific identification data such as 0x01. When it is determined that the content data is commercial, the content data can be deleted without being stored in the buffer unit 14.

  When the user data is not included in the GOP header of the received packet, the CM data deleting unit 15 determines that the received packet is a main packet (step S104) and does not delete the main packet.

  FIG. 7B is a diagram illustrating the buffer unit 14, main data, and CM data at the time of CM deletion. The buffer unit 14 temporarily stores CM data together with the main data. The CM data is deleted from the buffer unit 14 by the CM data deleting unit 15 (FIG. 1).

  When the change request transmission unit 16 determines that the amount of data stored in the buffer unit 14 has fallen below a predetermined threshold data amount (steps S106 and S208), the change request transmission unit 16 increases the transmission rate of the content data. Is transmitted to the VOD server 20 (steps S107 and S209). The change request receiving unit 24 of the VOD server 20 receives the transmission speed increase request transmitted from the change request transmitting unit 16 of the STB 10 via the communication network 30 (step S210).

  The transmission rate control unit 25 notifies the content transmission unit 23 of a transmission rate obtained by increasing the transmission rate of the content data by a predetermined amount in response to the transmission rate increase request received by the change request receiving unit 24. (Step S211). Thereafter, the content transmission unit 23 transmits the content data at the transmission speed notified from the transmission speed control unit 25.

  FIG. 7C is a diagram illustrating the buffer unit 14 and the main data when the buffer accumulation amount is below a predetermined threshold data amount. Since the CM data is deleted by the CM data deleting unit 15 (FIG. 1) and the main data is retrieved by the content reproducing unit 17 (FIG. 1) in the order of accumulation, the buffer unit is compared with the case shown in FIG. The main data stored in 14 has decreased. Since the content transmission unit 23 of the VOD server 20 increases the transmission speed of the content data, the content reception unit 13 (FIG. 1) of the STB 10 receives more main data P1 compared to the normal time.

  When the change request transmission unit 16 of the STB 10 determines that the amount of data stored in the buffer unit 14 exceeds a predetermined threshold data amount after the transmission speed increase request (steps S108 and S212), the transmission of content data is performed. A transmission speed normalization request for returning the speed to the normal transmission speed is transmitted to the VOD server 20 (steps S109 and S213). The change request receiving unit 24 of the VOD server 20 receives the transmission speed normalization request transmitted from the change request transmitting unit 16 of the STB 10 via the communication network 30 (step S214).

  In response to the transmission speed normalization request received by the change request receiving section 24, the transmission speed control section 25 notifies the content transmission section 23 of the transmission speed obtained by returning the transmission speed of the content data to the normal time (step S215). Thereafter, the content transmission unit 23 transmits the content data at the transmission speed notified from the transmission speed control unit 25.

  FIG. 7D is a diagram illustrating the buffer unit 14 and the main data when the buffer accumulation amount exceeds a predetermined threshold data amount. After the change request transmission unit 16 of the STB 10 transmits a transmission speed increase request to the VOD server 20, the content reception unit 13 (FIG. 1) receives more main data P1 (FIG. 7 (c)) compared to the normal time. Since it is received, more main data is stored in the buffer unit 14 than in the case shown in FIG. After the change request transmission unit 16 transmits the transmission speed normalization request to the VOD server 20, the content reception unit 13 (FIG. 1) receives the same amount of main data P2 as in the normal state. The data accumulation amount is kept constant.

  When the STB control unit 18 determines that all of the content data has been received (step S110), the content reception process ends. When the STB control unit 18 determines that all of the content data has not been received (step S110), the content reception process (steps S103 to S110) is continued.

  As described above, when the STB 10 of this embodiment determines whether the received packet is a main packet or a CM packet based on identification data included in the header of the received packet, and determines that the received packet is a CM packet In this case, the CM data included in the CM packet is deleted from the buffer. Further, the STB 10 of this embodiment determines whether the received packet is a main packet or a CM packet based on identification data included in the header of the received packet, and when determining that the received packet is a CM packet, The CM data included in the CM packet can be deleted without accumulating in the buffer. As a result, the CM data in the stream-distributed content data can be deleted in real time, and only the main part can be reproduced while receiving the content data.

  Even when the CM data is deleted or deleted, the main data in the buffer unit 14 is sequentially taken out for reproduction. Therefore, the main data in the buffer unit 14 may be temporarily reduced to cause an underflow. . Therefore, the STB 10 transmits a request to increase the transmission speed of the content data to the VOD server 20 when the main data storage amount in the buffer unit 14 falls below a predetermined lower limit value. As a result, the STB 10 receives a larger amount of content data than in the normal time, and therefore can compensate for the decrease in the main data amount in the buffer unit 14.

  If the amount of content data received per unit time increases due to the above processing, the buffer unit 14 may overflow. Therefore, the STB 10 transmits a request for returning the transmission rate of the content data to the normal transmission rate to the VOD server 20 when the main data storage amount in the buffer unit 14 exceeds a predetermined upper limit value. As a result, the STB 10 receives the same amount of main data as in normal times, so that the main data accumulation amount in the buffer unit 14 is kept constant. Since the same processing as described above is performed thereafter, the STB 10 can reproduce only the main part while receiving the content data without causing an overflow or an underflow.

  When a packet configured in accordance with the format of the MPEG2 standard is used, the VOD server 20 includes identification data for identifying whether the packet is a main packet or a CM packet in the GOP header and transmits it to the STB 10 To do. For example, user data such as 0x01 can be used as the identification data. With this identification data, the STB 10 can determine whether the received packet is a main packet or a CM packet.

1 Content Data Transmission / Reception System 10 Content Data Reception / Playback Device (STB)
11 Operation signal receiving unit 12 Content request transmitting unit 13 Content receiving unit (receiving unit)
14 Buffer unit (storage unit)
15 CM data deletion part (data deletion part)
16 Transmission speed change request transmission unit (change request transmission unit)
17 Content playback unit (playback unit)
18 STB control unit 20 VOD server 21 Content storage unit 22 Content request reception unit 23 Content transmission unit 24 Transmission speed change request reception unit (change request reception unit)
25 Transmission speed control unit 30 Communication network 40 Output unit 50 Remote control

Claims (15)

A receiver that sequentially receives packets streamed from the server via a communication network;
An accumulator that sequentially accumulates content data included in the packets received by the receiver;
A content data reception / playback device including a playback unit that sequentially retrieves and plays back the content data stored in the storage unit,
When it is determined that when the receiving unit receives one packet, the identification data included in the header of the one packet indicates that the content of one content data included in the one packet is commercial A content data receiving / reproducing apparatus, further comprising: a data deleting unit that deletes the one content data before or after storing the one content data in the storage unit.   And a change request transmitting unit configured to compare a storage amount of the content data in the storage unit with a predetermined amount and transmit a request to change the transmission rate of the packet to the server based on the result. Item 4. The content data receiving / reproducing apparatus according to Item 1.   The content data reception / playback apparatus according to claim 2, wherein the change request transmission unit transmits a request to increase the transmission speed when it is determined that the accumulated amount is less than the predetermined amount.   The content data according to claim 3, wherein the change request transmission unit transmits a request to return the transmission speed to the transmission speed before the increase when it is determined that the accumulated amount exceeds the predetermined amount. Reception playback device. The packet has a GOP structure configured according to the format of the MPEG2 standard,
5. The content data reception / playback apparatus according to claim 1, wherein the header is a GOP header. A server that transmits a packet including content data via a communication network in response to a content request and a packet that is stream-transmitted by the server are sequentially received via the communication network and the content data included in the packet is accumulated. A content data transmission / reception system including:
In the content data reception / playback apparatus, when the receiving unit receives one packet, the content of one content data in which the identification data included in the header of the one packet is included in the one packet is commercial. A content data transmission / reception system comprising: a data deletion unit that deletes one content data before or after storage of the one content data in the storage unit when it is determined that the content is present. The content data receiving / reproducing device includes a change request transmission unit that compares a storage amount of the content data in the storage unit with a predetermined amount and transmits a change request for the transmission rate of the packet to the server based on the result. In addition,
The content data transmission / reception system according to claim 6, wherein the server further includes a transmission rate control unit that changes the transmission rate in response to the request. The change request transmission unit transmits a request to increase the transmission speed when it is determined that the accumulated amount is less than the predetermined amount,
The content data transmission / reception system according to claim 7, wherein the transmission speed control unit increases the transmission speed in response to the request. The change request transmission unit transmits a request to return the transmission speed to the transmission speed before the increase when it is determined that the accumulated amount exceeds the predetermined amount,
The content data transmission / reception system according to claim 8, wherein the transmission speed control unit returns the transmission speed to the transmission speed before the increase in response to the request. The packet has a GOP structure configured according to the format of the MPEG2 standard,
The header is a GOP header;
The content data transmission / reception system according to any one of claims 6 to 9, wherein the server includes the identification data in the GOP header. A stream transmission step of transmitting a packet including content data via a communication network;
A reception step of sequentially receiving the packets transmitted in the stream transmission step via the communication network;
An accumulation step of accumulating content data included in the packet received in the reception step;
A content data transmission / reception method including: a reproduction step of sequentially retrieving and reproducing the content data accumulated in the accumulation step;
When it is determined in the reception step that the identification data included in the header of the one packet indicates that the content of the one content data included in the one packet is a commercial when one packet is received And a data deletion step of deleting the one content data before or after the storage of the one content data in the storage step.   12. The transmission rate changing step of comparing the storage amount of the content data stored in the storage step with a predetermined amount and changing the transmission rate of the packet based on the result thereof. The content data transmission / reception method described.   13. The content data transmitting / receiving method according to claim 12, wherein, in the transmission speed changing step, the transmission speed is increased when it is determined that the accumulated amount is less than the predetermined amount.   14. The content data transmitting / receiving method according to claim 13, wherein, in the transmission speed changing step, the transmission speed is returned to the transmission speed before the increase when it is determined that the accumulated amount exceeds the predetermined amount. The packet has a GOP structure configured according to the format of the MPEG2 standard,
The header is a GOP header;
15. The content data transmission / reception method according to claim 11, wherein the identification data is included in the GOP header in the stream transmission step.

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