JP5423661B2 - Network system, server, playback device, and content playback method - Google Patents

Description

  The present invention relates to a network system, a server, a playback device, and a content playback method for playing back content data recorded in real time via a network.

  When transmitting and receiving multimedia content such as video and audio in a so-called home network that integrates and manages devices in a predetermined range, if you try to time-shift playback of content data that is being recorded, you can easily set the seekable range. I can't figure it out. In an implementation in accordance with DLNA (Digital Living Network Alliance) guidelines, a playback device (DMP: Digital Media Player) requests a seekable range from a server (DMS: Digital Media Server) in parallel with acquisition of content data. By responding to it, it is possible to obtain a seekable range.

  By the way, there is a technique called “time shift playback” or “chase playback” which has become common in stand-alone HDD recorders. Until now, the recorded content data can be played back after the recording is completed. However, even if the time-shifted playback is the content data being recorded, it is possible to view or fast-forward / It also enables seek control such as rewinding. While recording, the viewable range, that is, the seekable range changes every moment. In addition to recording from the tuner, it is possible to play while downloading content data obtained via the Internet.

  Attempts have been made to realize this time shift reproduction between network devices. In the previous DLNA guidelines, content that has a limited seekable range, such as live streaming, is called a “Limited Random Access Data Availability” model.

  However, according to the DLNA guideline method, every time a seekable range is acquired, a new connection is repeatedly opened and closed by an interrupt event, which is a heavy load on both the server and the playback device. In addition, when the server or the playback device controls to give priority to transmission / reception of content data, there is a problem that a request and acquisition of a seekable range are not performed at any time.

  On the other hand, a technology has been proposed in which the playback device makes a single event request and thereafter only needs to receive content data and obtain a seekable range, and new connections are not frequently opened or closed. (See Patent Document 1).

Japanese Patent No. 4305004

  However, even in the technology of Patent Document 1, in order to acquire a seekable range of content data, a connection different from the content transmission / reception connection is required.

  As described above, the need for a connection different from the content transmission / reception connection increases the load on the server and the playback apparatus that transmit / receive these contents as the number of contents to be simultaneously connected increases. Further, when the playback device is an embedded device such as a home appliance, it has been a cause of resource shortage.

  The present invention has been made in view of the above-described problems, and can obtain a seekable range of content data without requiring a new connection other than a content transmission / reception connection between a server and a playback device. An object of the present invention is to provide a network system, a server, a playback device, and a content playback method that can make an appropriate seek request.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a recording unit (12) for recording content data as time series data, and a range recorded in the recording unit (12) of the content data. Dividing unit (14) for creating a plurality of partial data by dividing and creating size information for each of the plurality of partial data, seekable range information indicating the range recorded in the recording unit (12) of the content data Is added to the size information, and in response to a request transmitted from the playback device (20) for playing back the content data, the partial data and the size information of the partial data to which seekable range information is added Server (10) including a transmission unit (16) for transmitting the content, and transmission unit (21) for transmitting a request for requesting content data to the server (10), in response to the request A receiver (22) for receiving the partial data and the size information of the partial data to which seekable range information is added, transmitted from the host (10), and a reproducing unit (25,) for reproducing the received partial data 26) a network including a playback device (20) including a request creation unit (24) that creates a request to request playback from a logical position within the range indicated by the seekable range information acquired by the request in the content data The gist is that it is a system.

  According to a second aspect of the present invention, a recording unit (12) that records content data that is time-series data, and a portion of the content data that is recorded in the recording unit (12) is divided into a plurality of partial data. And a division unit (14) for generating size information for each of a plurality of partial data, and seekable range information indicating the range recorded in the recording unit (12) of the content data is added to the size information. In response to a request transmitted from the adding unit (15) and the playback device (20) that plays back the content data, the playback device (20) receives the partial data and the size information of the partial data to which seekable range information is added. The gist of the present invention is that the server comprises a transmission unit (16) for transmission to the server.

  In the third aspect of the present invention, a transmission unit (21) that transmits a request for requesting content data to a server (10) that records content data that is time-series data, and a transmission from the server (10) in response to the request. Reception of received partial data that is part of the content data and size information of the partial data to which seekable range information indicating the range recorded in the server (10) is added. Unit (22), reproduction unit (25, 26) that reproduces the partial data received by the reception unit (22), and the content data from the logical position within the range indicated by the seekable range information acquired by the request The gist of the present invention is that the playback apparatus includes a request creation unit (24) that creates a request for playback.

  According to a fourth aspect of the present invention, the server (10) records the content data as time series data in the recording unit (12), and the server (10) includes the recording unit (12) in the content data. A step of creating a plurality of partial data by dividing the range recorded in the table, and creating size information for each of the plurality of partial data, and the server (10) records the content data in the recording unit (12) The step of adding seekable range information indicating the range that has been set to the size information and the playback device (20) that reproduces the content data, the partial data and the seekable range information to which the seekable range information has been added. The step of transmitting the size information, the step of the playback device (20) transmitting a request for requesting content data to the server (10), and the playback device (20) Receiving the partial data and the size information of the partial data to which the seekable range information is added, transmitted from the server (10) in response to the request; and the playback device (20) Content reproduction including a reproduction step and a step in which the reproduction device (20) creates a new request for requesting reproduction from a logical position within the range indicated by the seekable range information acquired by the request in the content data. The gist is the method.

  According to the present invention, it is possible to obtain a seekable range of content data and make an appropriate seek request without requiring a new connection other than the content transmission / reception connection between the server and the playback device. A network system, a server, a playback device, and a content playback method can be provided.

It is a typical block diagram explaining the basic composition of the network system concerning a 1st embodiment of the present invention. It is a sequence diagram explaining operation | movement of the server of the network system which concerns on the 1st Embodiment of this invention. It is an example which illustrated data amount versus time information used for the network system concerning a 1st embodiment of the present invention. It is a sequence diagram explaining operation | movement of the server and reproducing | regenerating apparatus of the network system which concerns on the 1st Embodiment of this invention. It is a flowchart explaining the server and reproducing | regenerating apparatus of the network system which concern on the 1st Embodiment of this invention. It is an example which illustrated the structure of the data transmitted / received in the network system which concerns on the 1st Embodiment of this invention. 2 is an example illustrating the structure of data to be transmitted and received in order to explain the operation of the network system according to the first embodiment of the present invention. 2 is an example illustrating the structure of data to be transmitted and received in order to explain the operation of the network system according to the first embodiment of the present invention. It is a sequence diagram explaining the conventional content reproduction | regeneration method. It is a sequence diagram explaining the conventional content reproduction | regeneration method. It is a typical block diagram explaining the basic composition of the network system concerning a 2nd embodiment of the present invention. It is a flowchart explaining operation | movement of the server of the network system which concerns on the 2nd Embodiment of this invention. It is a flowchart explaining operation | movement of the server and reproducing | regenerating apparatus of the network system which concerns on the 2nd Embodiment of this invention. It is an example which illustrated the structure of the data transmitted / received in order to demonstrate operation | movement of the network system which concerns on the 2nd Embodiment of this invention. It is an example which illustrated the structure of the data transmitted / received in order to demonstrate operation | movement of the network system which concerns on the 2nd Embodiment of this invention. It is an example which illustrated the structure of the data transmitted / received in order to demonstrate operation | movement of the network system which concerns on the 2nd Embodiment of this invention.

  Next, first and second embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
As shown in FIG. 1, the network system according to the first embodiment of the present invention records and transfers content data, which is time-series data such as audio data and moving image data, via a network 30. A playback device 20 that is communicably connected to the server 10 and that plays back the content data recorded in the server 10 is provided. Communication between the server 10 and the playback device 20 is performed by a hypertext transfer protocol (HTTP).

  FIG. 2 is a flowchart for explaining the operation of the server 10 when recording content data.

  In step S11, the external content acquisition unit 11 of the server 10 acquires content data from a tuner that receives various broadcasts, the Internet, or the like. In addition, the content data acquired by the external content acquisition unit 11 may be a sound or a moving image reproduced by another reproducing device (not shown), a moving image shot by a photographing device (not shown), or the like.

  In step S12, the external content acquisition unit 11 causes the recording unit 12 to sequentially record the acquired content data. The recording unit 12 can be configured by, for example, a volatile storage device such as SRAM or DRAM, or a nonvolatile storage device such as a magnetic disk such as a hard disk (HD), a magnetic tape, an optical disk, or a magneto-optical disk. In addition, the recording unit 12 can employ a RAM disk, an IC card, a flash memory card, a USB flash memory, a flash disk (SSD), or the like.

  The content data recorded in the recording unit 12 includes, for example, MPEG (Moving Picture Experts Group), Motion JPEG (Motion Joint Photographic Experts Group), H series standards of the International Telecommunication Union Telecommunication Standardization Sector (ITU-T), etc. It is digital data such as sound and moving image processed by various methods.

  In step S13, the data amount versus time information creation unit 13 reads the content data acquired by the external content acquisition unit 11 and recorded in the recording unit 12, and from the top of the content data to a certain logical position in the content data. Data amount versus time information, which is information in which the data amount is associated with the reproduction time, is created. For example, as shown in FIG. 3, the data amount versus time information may be information in a table format in which the value of the data amount is associated with the reproduction time.

  In step S14, the external content acquisition unit 11 determines whether or not recording of the entire content data has been completed. If the recording of the entire content data has not been completed, the processes in steps S11 to S13 are repeated. When the recording of the entire content data is completed, the process ends.

  The operation of the network system according to the first embodiment will be described with reference to FIGS.

  FIG. 4 is a diagram showing a data transmission / reception sequence between the server 10 and the playback device 20. FIG. 5 is a flowchart showing each step of the operations of the server 10 and the playback device 20. In the following description, FIG. 5 is mainly used.

  First, in step S <b> 101, the request transmission unit 21 of the playback device 20 transmits a request header for requesting content data recorded in the recording unit 12 of the server 10 to the server 10. The request header is an HTTP request message including a GET method.

For example, as illustrated in FIG. 6, the request transmission unit 21 transfers the content data B having the file name “movie.mpg” to the server 10 having the unified resource identifier (URI) “192.168.0.1.00” as “HTTP”. /1.1 "protocol,
GET / movie. mpg HTTP / 1.1
Host: 192.169.100
A request header including such a description is transmitted to the server 10.

In step S <b> 102, the request communication unit 17 of the server 10 receives a request header for requesting the content data B transmitted from the request transmission unit 21 of the playback device 20.

  In step S <b> 103, the request communication unit 17 transmits a response header for the request header to the playback device 20.

  For example, when the request header transmitted from the playback device 20 requests the content data B whose entire size is already recorded in the recording unit 12 and the total size is known, the request communication unit 17 displays the request communication unit 17 in FIG. As shown, a “Content-Length” header indicating the size of the entire content data B is included in the response header.

  When the request header transmitted from the playback device 20 requests the content data B whose entire size is not recorded in the recording unit 12 and whose total size is unknown, the request communication unit 17 is as shown in FIG. In the response header, a “Transfer-Encoding: chunked” header indicating that the content data B is to be transmitted to the playback device 20 in the chunk format is included.

  In step S <b> 104, the playback device 20 receives the response header transmitted from the request communication unit 17 of the server 10.

In step S105, the content dividing unit 14 acquires a portion of the content data B recorded in the recording unit 12, and converts the acquired content data B into a plurality of partial data b ₁ , b _{2 ,.} m: a positive integer). The content dividing unit 14 creates divided content in a chunk format including partial data b _i (i: an integer from 1 to m ₎ and size information s _i that is the data amount of the partial data b _i .

In step S106, the seekable range information adding unit 15 acquires seekable range information from the data amount versus time information creating unit 13, and can seek to the size information s _i of the partial data b _i divided by the content dividing unit 14. Add range information.

  The seekable range information is information created by the data amount vs. time information creation unit 13 based on the created data amount vs. time information, and seek operations such as rewind and fast forward by the playback device 20 in the content data B Is a data amount and reproduction time information of the content data B recorded in the recording unit 12 at a certain point in time indicating a possible range.

For example, if the playback time of the content data B is 0.0 to 3.0 seconds and the data amount is in the range of 0 to 2880000 bytes, the seekable range information is:
2BF200; npt = 0.0-3.0 bytes = 0-28800000
As shown below, after “; (semicolon)”, it is added to the size information s _i = 2BF200 bytes (decimal number 2880000 bytes) of the partial data b _i by a character string such as “npt =”, “bytes =”, etc. The

  In HTTP communication, “; (semicolon)” is generally a delimiter (delimiter), and characters after the semicolon are generally ignored as comments. Therefore, the server 10 included in the network system according to the first embodiment is not the playback device 20 of the network system according to the first embodiment, but is another playback device that acquires and plays back content data according to the HTTP protocol. Even if it exists, acquisition and reproduction of content data are possible, and versatility is high.

In step S107, the divided content transmitter 16, a partial data b _i, is added to the seek range information by the seek range information adding section 15, the divided content consisting of size information s _i of the partial data b _i, It is transmitted to the playback device 20 as part of the response body for the request header.

In step S108, divided content transmission unit 16 determines whether or not to transmit all the partial data _b 1 ~b _m. If it is determined that all the partial data b _{1 to} b _m have not been transmitted yet, the process returns to step S105, and the processes of steps S105 to S107 are repeated.

When determining that all the partial data b _{1 to} b _m have been transmitted, in step S109, the seekable range information adding unit 15 sets the data amount and playback time of the entire content data B to the size information s _n = 0. It is added as possible range information.

In step S _< b _> 110, the divided content transmission unit 16 transmits the size information sn with the seekable range information of the entire content data B added thereto to the playback device 20. Size information _{s n,} by being received in the reproducing apparatus 20, the reproduction apparatus 20 notifies that the server 10 has sent all of the partial data _b 1 ~b _m.

In step S111, the divided content receiving unit 22 of the playback device 20 uses, as a response body transmitted from the server 10, the partial data b _i and the size information s _i of the partial data b _i to which seekable range information is added. divided content chunked made or seek range information, receives the size information s _n which is added.

  The divided content receiving unit 22 receives data transmitted from the server 10 such as a response header transmitted from the server 10.

In step S112, the seek range information analysis unit 23 is described after the size information s _i or size information s _n, the partial data b _i where divided content receiving unit 22 has received; recognize later "(semicolon)" Whether or not seekable range information is added is determined. When the seekable range information is not added, the process proceeds to step S114.

If the seek range information is added, in step S113, the seek range information analysis unit 23 analyzes the data amount and the reproduction time of the seek range information added to the size information s _i, holds. Accordingly, the seekable range information of the content data B is sequentially notified from the server 10 to the playback device 20.

In step S114, it is determined whether or not the size information is s _n = 0. When the size information is s _n = 0, the reproducing device 20 determines that all the partial data b _{1 to} b _m have been received, and ends the reception of the divided content in step S111.

If the size information is not _s n = 0, in step S115, sequentially decodes the decode unit 25 partial data _{b i} of the reproduction portion (25, 26), at step S116, the output unit of the reproducing unit (25, 26) 26 outputs the decoding result of the decoding unit 25 to reproduce the content data B, and returns to step S111.

  Further, in step S117 as appropriate, the seek request creation unit 24 transmits from an arbitrary position in the content data B recorded in the recording unit 12 of the server 10 in response to a seek operation such as rewinding or fast-forwarding the content data. For the server 10 is created.

  The seek request creation unit 24 reads the seekable range information held by the seekable range information analysis unit 23 from the seekable range information analysis unit 23, and indicates the logical position within the range of the seekable range information. Create a seek request that includes the amount of data or playback time. The seek operation is input to the seek request creation unit 24 from an input device (not shown) according to the user's operation, and the data request or the playback time of the content data B within the range indicated by the seekable range information is created. Specified in part 24.

  In response to the seek request created by the seek request creation unit 24, the playback device 20 causes the server 10 to perform seek, such as rewind and fast forward, without interrupting the server 10 when playing back the content data B that is not recorded entirely. Operation is possible.

  FIG. 7 is a diagram for explaining a case where the playback of the content data B by the playback device 20 is started immediately after the start of recording of the content data B by the server 10 in the network system according to the first embodiment. The content data B is data that has been acquired by the external content acquisition unit 11 and is being recorded in the recording unit 12 and has not been recorded.

The content data B shown in FIG. 7A is started to be recorded in the recording unit 12 by the external content acquisition unit 11 of the server 10 at a recording speed equal to the actual reproduction time of the content data B. Content dividing portion 14, in response to a request header sent from the reproducing apparatus 20, first, from the content data B is recorded in the recording unit 12, a partial data b _1, and the size information s ₁ of the partial data b ₁ create.

The seekable range information adding unit 15 adds the seekable range information “npt = 0.0” created by the data amount versus time information creating unit 13 to the size information s ₁ of the partial data b ₁ created by the content dividing unit 14. -3.0 bytes = 0-28800000 ”is added. Divided content transmission unit 16 has been added to the seek range information, and size information s ₁ of the partial data b _1, and a partial data b _1, and transmits to the playback device 20.

The divided content receiving unit 22 of the playback device 20 receives the partial data b ₁ of the content data B transmitted from the server 10 and the size information s ₁ of the partial data b ₁ . The seekable range information analysis unit 23 acquires and holds seekable range information added to the size information s ₁ of the partial data b ₁ .

As shown in FIG. 7B, the size information s ₁ of the partial data b ₁ included in the response body received by the playback device 20 is “2BF200 (2880000 bytes in decimal)”, and “;” Later, seekable range information added to the size information s ₁ is “npt = 0.0−3.0 bytes = 0−2880000”. The seekable range information added to the size information s ₁ is a seek operation in the range where the reproduction time of the content data B is 0.0 seconds to 3.0 seconds and the data amount value is 0 bytes to 2880000 bytes. It shows that there is.

Therefore, for example, when the reproducing device 20 reproduces the content of the partial data b ₁ at time t ₁ shown in FIG. 7B, the seekable range held by the seekable range information analyzing unit 23 at time t ₁ . It is possible to perform a seek operation for reproducing a position within the information range. The seek request creation unit 24 reproduces the position of the reproduction time 1 second from the beginning in the content data B “movie.mpg” recorded in the server 10 whose address is “192.168.0.100”. For example, to
GET / movie. mpg HTTP / 1.1
Host: 192.169.100
TimeSeekRange. dlna. org: npt = 1.0−
The request transmission unit 21 transmits the seek request generated by the seek request generation unit 24 to the server 10 as a request header.

In addition, when performing a seek operation for reproducing the content data B recorded in the server 10 from the position where the value of the data amount is 1440000 bytes from the beginning, the seek request creation unit 24, for example, obtains GET / movie. mpg HTTP / 1.1
Host: 192.169.100
RANGE: bytes = 1440000-
The request transmission unit 21 transmits the seek request generated by the request transmission unit 21 to the server 10 as a request header.

Similarly, at time t ₂ shown in FIG. 7 (B), when reproducing the contents of the partial data b _i-1 content data B, the seek range information seek range information analysis section 23 holds the "npt = 0 0.0-147.0 bytes = 0-141120,000 ”, the playback device 20 sets the playback time of the content data B from 0 seconds to 147 seconds, and the data amount ranges from 0 bytes to 141120,000 bytes. This indicates that a seek operation can be specified. In addition, when the content data B is played immediately before the playback time of 147 seconds, seek playback in the fast-forward direction cannot be performed, and a seek operation in the rewind direction up to the playback time of 0 seconds is possible.

  The playback device 20 can perform a seek operation to arbitrarily specify the playback time of the content data B and the value of the data amount within the range of seekable range information held by the seekable range information analysis unit 23.

  FIG. 8 is a diagram related to FIG. 7 in the case where the playback of the content data B by the playback device 20 is started 30 seconds after the start of recording of the content data B by the server 10 in the network system according to the first embodiment. FIG.

Content data B shown in FIG. 8A is started to be recorded in the recording unit 12 by the external content acquisition unit 11 of the server 10 at a recording speed that is the same as the actual reproduction time of the content data B. In response to a request header transmitted from the playback device 20 30 seconds after the start of recording of the content data B, the content dividing unit 14 receives the partial data b _i and the partial data b from the content data B recorded in the recording unit 12. _i size information s _i is created.

As shown in FIG. 8B, the size information s ₁ of the partial data b ₁ included in the response body received by the playback apparatus 20 is “2BF200 (2880000 bytes in decimal)”, and the size information s ₁ The seekable range information added to “npt = 0.0-30.0 bytes = 0−28800000”. The seekable range information added to the size information s ₁ can be searched when the playback time of the content data B is 0.0 seconds to 30.0 seconds and the value of the data amount is 0 bytes to 28800000 bytes. It shows that there is.

Therefore, for example, when the reproducing device 20 reproduces the content of the partial data b ₁ at time t ₃ shown in FIG. 8B, the seekable range held by the seekable range information analysis unit 23 at time t ₃ . A seek operation can be performed at a position within the information range. In the case where the position of the playback time of the content data B is 3 seconds, it is shown that the fast-forward seek operation up to the playback time 30 seconds and the rewind seek operation up to the playback time 0 seconds are possible. Yes.

Similarly, at time t ₄ when shown in FIG. 8 (B), when reproducing the contents of the partial data b _i-1 content data B, the seek range information seek range information analysis section 23 holds the "npt = 0 0.0-147.0 bytes = 0-141120,000 ”, the playback device 20 sets the playback time of the content data B from 0 seconds to 147 seconds, and the data amount ranges from 0 bytes to 141120,000 bytes. This indicates that a seek operation can be specified.

  Further, the server 10 may perform streaming for transmitting the content data to the playback device 20 while performing buffering in which the recording unit 12 of the server 10 temporarily stores the content data cyclically. For example, the recording unit 12 can be a volatile storage device for dividing and transmitting content data without aiming to record content data.

For example, when the content data to be broadcast is streamed to the playback device 20 in real time while buffering the content data to the recording unit 12 for 300 seconds, the seekable range information adding unit 15 uses the size information s of the partial data b _{i. The} seekable range information added to _i is
npt = 0.0-300.0 bytes = 0-288000000
npt = 10.0-310.0 bytes = 9600000-297600000
npt = 20.0-320.0 bytes = 19200000-372100000
As described above, both the start time and end value of the reproduction time and the data amount of the seekable range information change every moment.

  In the conventional implementation according to the DLNA guideline, as shown in FIG. 9, the playback apparatus 200 requests a seekable range from the server in parallel with the playback of the content data, and the server obtains the seekable range by responding to the request. Is possible. However, in this method, every time a seekable range is acquired, as shown in FIG. 9, opening and closing of a new connection C2 by an interrupt event, which is different from the connection C1 that transmits and receives content data, is repeated. As a result, both the playback apparatus 200 and the server 100 have become a heavy load. In addition, when the server 100 and the playback device 200 are controlled so as to give priority to transmission / reception of content data, there is also a problem that a requestable / acquisition of a seekable range is not performed in a timely manner.

Similarly, in the technique described in Patent Document 1 (Japanese Patent No. 4305004), as shown in FIG. 10, the server 100 periodically notifies the seekable range only by making a single event request. However, a new connection C3 based on an interrupt event is required, which is different from the connection C1 that transmits and receives content data.

  According to the network system according to the first embodiment, it is not necessary for the playback device to repeatedly make inquiries to the server, and there is no need for a new connection separate from content transmission / reception due to an interrupt event. A seek request can be made.

(Second Embodiment)
In the network system according to the second embodiment of the present invention, the server 10 includes a partial size determination unit 18 and changes the size of the partial data b _i according to the communication speed between the server 10 and the playback device 20. This is different from the first embodiment.

  FIG. 12 is a flowchart for explaining the operation when the server 10 of the network system according to the second embodiment records content data.

  In step S21, the external content acquisition unit 11 of the server 10 acquires content data such as audio data and moving image data from a tuner, the Internet, or the like.

  In step S22, the external content acquisition unit 11 causes the recording unit 12 to record the acquired content data sequentially.

  In step S23, the data amount versus time information creation unit 13 reads the content data acquired by the external content acquisition unit 11 and recorded in the recording unit 12, and from the top of the content data to a certain logical position in the content data. Data amount versus time information, which is information in which the data amount is associated with the reproduction time, is created.

In step S24, the data amount vs. time information creation unit 13 performs the time _Tr required for recording the content data recorded in the recording unit 12 and the actual time when reproducing the content data recorded in the recording unit 12. calculating a recording magnification R _m is the ratio of the reproduction time T _a of. Recording magnification _{R m} is calculated from equation (1).

R _m = T _a / T _r (1)
When the recording of the entire content data is completed, the recording magnification R _m = 0.

The recording magnification R _m is equal to (1 ×) when recording audio and moving image data broadcasted in real time, such as recording from a tuner. Depending on the magnification. If internet is fast, the recording magnification R _m is doubled, if slow sometimes becomes 1/2 times.

  In step S25, the external content acquisition unit 11 determines whether recording of the entire content data has been completed. If the recording of the entire content data has not been completed, the processes in steps S21 to S24 are repeated. When the recording of the entire content data is completed, the process ends.

  Operations of the server 10 and the playback device 20 included in the network system according to the second embodiment will be described with reference to the flowchart of FIG.

  First, in step S <b> 201, the request transmission unit 21 of the playback device 20 transmits a request header for requesting content data recorded in the recording unit 12 of the server 10 to the server 10.

  In step S202, the request communication unit 17 of the server 10 receives a request header for requesting the content data B transmitted from the request transmission unit 21 of the playback device 20, and in step S203, the request communication unit 17 receives the request header. To the playback device 20.

  In step S <b> 204, the playback device 20 receives the response header transmitted from the request communication unit 17 of the server 10.

In step S205, the partial size determination unit 18 of the server 10 determines the data amount (size information s _i ) of the partial data b _i to be transmitted to the playback device 20.

Portion size determination unit 18, first, and time T _s required for transmission of Sent partial data b _i, transmission ratio is the actual reproduction ratio of time T _p at the time of reproducing the partial data b _i of Sent P _m is calculated. The transmission magnification _Pm is calculated from the equation (2).

P _m = T _p / T _s (2)
The actual reproduction time T _p of the partial data b _i can be obtained from the data amount versus time information created by the data amount versus time information creation unit 13. Since there is no transmitted partial data b _i at the transmission start stage, the transmission magnification may be assumed to be P _m = 1.

For example, when the server 10 transmits the partial data b _i for the reproduction time of 30 seconds in 10 seconds, P _m = 30/10 = 3. The transmission magnification P _m can also be a magnification between the reception time of the partial data b _i of the playback device 20 and the playback time, and the reception time of the partial data b _i depends on the playback speed of the playback device 20. Will change.

The partial size determination unit 18 further determines the interval time T _i based on the recording magnification R _m of the content data being recorded and the transmission magnification P _m . The interval time T _i is calculated from the equation (3).

T _i = T _d × (P _m / R _m ) (3)
The reference time T _{d in} Expression (2) is an interval at which the server 10 notifies the playback device 20 of seekable range information under the condition of recording magnification R _m = transmission magnification P _m .

The partial size determination unit 18 inquires the interval time T _i with the data amount versus time information held by the data amount versus time information creation unit 13 and transmits the data amount (size information s) of the partial data b _i to be transmitted to the playback device 20. _i ) is determined.

When the recording of the content data is completed in the server 10, the recording magnification R _m = 0 and the interval time T _i = ∞, so that all the remaining partial data b _i of the size information s _i are stored in the playback device 20. Send.

For example, if the reference time T _d = 3 seconds, if the recording magnification R _m and the transmission magnification P _m are equal, the size information s _i of the partial data b _i to be transmitted is the partial data for the actual reproduction time of 3 seconds. b _i size information s _i Nearby, seek range information will be notified to the playback device 20 at 3 second intervals from the server 10.

When the recording magnification R _m = 2 and the transmission magnification P _m = 1, the interval time T _i = 3 × (1/2) = 1.5 seconds, and the server 10 sets the seekable range information to 1.5 seconds. The playback device 20 is notified at intervals. Note that the range of the reproduction time indicated by the seekable range information is expanded by 3 seconds.

Similarly, when the recording magnification R _m = 1 and the transmission magnification P _m = 2, the interval time T _i = 3 × (2/1) = 6, and the server 10 reproduces the seekable range information at intervals of 6 seconds. The device 20 is notified.

In step S206, the content dividing unit 14 divides the content data, and creates the size information s _i determined by the partial size determining unit 18 and the partial data b _i of the size information s _i .

  The processing after step S207 shown in FIG. 13 is substantially the same as the processing after step S106 shown in FIG. 5 described in the first embodiment, and therefore, redundant description is omitted.

  FIG. 14 is a diagram for explaining a case where the playback of the content data B by the playback device 20 is started 30 seconds after the start of recording of the content data B by the server 10 in the network system according to the second embodiment. .

Recording of content data B shown in FIG. 14A by the external content acquisition unit 11 of the server 10 is started in the recording unit 12 at a recording speed that is the same as the actual reproduction time of the content data B. When the reference time _Td is 3 seconds, the partial size determination unit 18 has the recording magnification R _m = 1 and the initial transmission magnification P _m = 1, so that the interval time T _i = 3 × (1/1) = 3. Seconds are calculated, and size information s _i is determined based on the interval time T _i . In response to a request header transmitted from the playback device 20 30 seconds after the start of recording of the content data B, the content dividing unit 14 receives the partial data b _i and the partial data b from the content data B recorded in the recording unit 12. _i size information s _i is created.

As illustrated in FIG. 14B, the size information s ₁ of the partial data b ₁ included in the response body received by the playback device 20 is “2BF200 (2880000 bytes in decimal)”, and the size information s ₁ The seekable range information added to “npt = 0.0-30.0 bytes = 0−28800000”. The seekable range information added to the size information s ₁ can be searched when the playback time of the content data B is 0.0 seconds to 30.0 seconds and the value of the data amount is 0 bytes to 28800000 bytes. It shows that there is.

Therefore, for example, when the reproducing device 20 reproduces the content of the partial data b ₁ at time t ₅ shown in FIG. 14B, the seekable range held by the seekable range information analyzing unit 23 at time t ₅ . A seek operation can be performed at a position within the information range. In the case where the position of the playback time of the content data B is 3 seconds, it is shown that the fast-forward seek operation up to the playback time 30 seconds and the rewind seek operation up to the playback time 0 seconds are possible. Yes.

Similarly, at time t ₆ shown in FIG. 14 (B), when reproducing the contents of the partial data b _m of the content data B, has the entire content data B recording is completed, the seek range information analysis unit 23 is held The seekable range information to be performed is “npt = 0.0−150.0 bytes = 0−144000000”. The playback device 20 indicates that a seek operation can be performed to specify each of the content data B within a playback time range of 0 to 150 seconds and a data amount value of 0 to 1444,000 bytes.

As shown in FIG. 14A, the server 10 ends the recording of the content data B in 150 seconds from the start of recording. In this case, since the server 10 finishes recording the content data B while the playback device 20 is playing back the content data B with a playback time of about 120 seconds, the interval time T _i = 3 × (1/0) = ∞, As shown in FIG. 14B, the server 10 transmits all the remaining content data B that has not yet been transmitted as the partial data b _m of the size information s _m = 20F5800 (34560000 bytes in decimal). The seekable range information “npt = 0.0-150.0 bytes = 0-144000000” at this time indicates the playback time and data amount values of the entire content data B.

As shown in FIG. 14B, after transmitting the last partial data b _m , the server 10 transmits size information s _n = 0 indicating that the transmission of the divided content is completed. The seekable range information added to the size information s _n = 0 is the same as the seekable range information transmitted immediately before.

  FIG. 15 is a diagram for explaining a case where the playback of the content data B by the playback device 20 is started immediately after the start of recording of the content data B by the server 10 in the network system according to the second embodiment.

The content data B shown in FIG. 15A is recorded by the external content acquisition unit 11 of the server 10 at a recording speed (recording magnification R _m = 2) that is twice the actual playback time of the content data B. To start recording. If the reference time _Td is 3 seconds, the partial size determination unit 18 has the recording magnification R _m = 2 and the initial transmission magnification P _m = 1, so that the interval time T _i = 3 × (1/2) = 1. Calculate 5 seconds and determine the size information s _i based on the interval time T _i . In response to a request header transmitted from the playback device 20 30 seconds after the start of recording of the content data B, the content dividing unit 14 receives the partial data b _i and the partial data b from the content data B recorded in the recording unit 12. _i size information s _i is created.

As shown in FIG. 15B, the size information s ₁ of the partial data b ₁ included in the response body received by the playback device 20 is “15F900 (1440000 bytes in decimal)”, and FIG. The server 10 transmits the seekable range information at an interval that is 1/2 times that of the example shown in FIG. 7B. The seekable range information added to the size information s ₁ is “npt = 0.0-30.0 bytes = 0−28800000”, which is the same as the example shown in FIG.

For example, when the reproducing device 20 reproduces the content of the partial data b ₁ at time t ₇ shown in FIG. 15B, the seekable range information held by the seekable range information analyzing unit 23 at time t ₇ . A seek operation can be performed at a position within the range. In the case where the position of the playback time of the content data B is 3 seconds, the fast forward seek operation up to the playback time 3 seconds and the rewind seek operation up to the playback time 0 seconds are possible. Yes.

Similarly, FIG. 15 at time t ₈ that (B), the content during reproduction of the contents of the partial data b _i-1 of the data B, the seek range information it seeks range information analysis section 23 holds the "npt = 0 0.0-297.0 bytes = 0-2865600000 ”, the playback device 20 has a playback time of the content data B from 0 seconds to 297 seconds, and the data amount ranges from 0 bytes to 28656000 bytes, respectively. This indicates that a seek operation can be specified.

  FIG. 16 is a diagram for explaining a case where, in the network system according to the second embodiment, double-speed playback of content data B by the playback device 20 is started 30 seconds after the start of recording of content data B by the server 10. It is.

Content data B shown in FIG. 16A is recorded at a recording speed (recording magnification R _m = 1) equal to the actual reproduction time of content data B by the external content acquisition unit 11 of the server 10 at the recording unit 12. To start recording. _Assuming that the reference time _Td is 3 seconds, the partial size determination unit 18 sets the interval time T _i = 3 × (1/1) = 3 seconds from the recording magnification R _m = 1 and the initial transmission magnification P _m = 1. The size information s _i is calculated based on the interval time T _i . In response to a request header transmitted from the playback device 20 30 seconds after the start of recording of the content data B, the content dividing unit 14 receives the partial data b _i and the partial data b from the content data B recorded in the recording unit 12. _i size information s _i is created.

As shown in FIG. 16 (B), the size information s ₁ of the partial data b ₁ included in the response body received by the playback device 20 is “22BF200 (2880000 bytes in decimal number)”. Since the size information s ₂ of the partial data b ₂ is the transmission magnification P _m = 2, “57E400 (decimal number 5760000 bytes)” and the seekable range information to be added are “npt = 0.0−31. 5 bytes = 0-302400000 ”.

  The increase in the seekable range information is ½ times that in the example shown in FIG. 7B, and the server 10 obtains the seekable range information at an interval twice that in the example shown in FIG. Sending.

For example reproducing apparatus 20, at time t ₉ shown in FIG. 16 (B), when playing the contents of the partial data b _1, seek range information analysis unit 23 at time t ₉ is the seek range information held A seek operation can be performed at a position within the range. In the case where the position of the playback time of the content data B is 3 seconds, it is shown that the fast-forward seek operation up to the playback time 30 seconds and the rewind seek operation up to the playback time 0 seconds are possible. Yes.

Similarly, at time t ₉ shown in FIG. 16 (B), when reproducing the contents of the partial data b _i-1 content data B, the seek range information seek range information analysis section 23 holds the "npt = 0 0.0-58.5 bytes = 0-5616000 ”, and the playback apparatus 20 has a playback time of the content data B from 0 seconds to 58.5 seconds, and the data amount ranges from 0 bytes to 5616000 bytes. This indicates that a seek operation for specifying each can be performed.

In the example shown in FIG. 16, since the playback device 20 plays back the content data B at double speed, the position recorded by the server 10 in the content data B when the playback time reaches 60 seconds. to catch up, since the transmission ratio Pm and recording magnification Rm coincide, size information _{s i} of the partial data _{b i} is "22BF200 (10 in decimal 2,880,000 bytes)".

  The other description of the network system according to the second embodiment is substantially the same as the description of the network system according to the first embodiment, and thus a duplicate description is omitted.

According to the server 10 the network system comprises according to a second embodiment, the recording magnification R _m high seek range information in a smaller space in rapidly changing conditions, the transmission ratio P _m is high seek range The notification interval of seekable range information can be automatically adjusted in a large interval in situations where notification of information is not frequently required, and also in consideration of the situation where recording is complete and seekable range information does not change.

  Further, according to the network system according to the second embodiment, it is not necessary for the playback device to repeatedly make inquiries to the server, and a new connection separate from content transmission / reception due to an interrupt event is unnecessary, and an appropriate range. Can make a seek request.

(Other embodiments)
As described above, the present invention has been described according to the first and second embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the first and second embodiments already described, the functions of the network system and the server may be realized using a program for causing a computer to realize the functions. That is, it includes a program for causing a computer to realize the functions of the network system and the server according to the first and second embodiments. The program may be read from a recording medium and loaded into a computer, or may be transmitted via a network and loaded into a computer.

  In addition to the above, of course, the present invention includes various embodiments and the like not described here, such as configurations to which the first and second embodiments are applied. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 10 ... Server 11 ... External content acquisition part 12 ... Recording part 13 ... Data amount vs. time information creation part 14 ... Content division part 15 ... Seekable range information addition part 16 ... Divided content transmission part 17 ... Request communication part 18 ... Partial size Determining unit 20 ... playback device 21 ... request transmission unit 22 ... divided content reception unit 23 ... seekable range information analysis unit 24 ... seek request creation unit 25 ... decoding unit 26 ... output unit 30 ... network 100 ... server 200 ... playback device

Claims (8)

A server for transmitting content data for reproduction to a reproduction device via a communication network,
An acquisition unit that partially acquires the content data from the outside multiple times ;
A recording unit for recording a portion of the content data acquired by the acquisition unit,
A request for requesting the recording unit to start transmission of the content data being recorded, which is transmitted via the communication network in response to an operation for instructing the user to specify the content data and to start the reproduction to the playback device . And a seek request for transmitting the content data from the position, which is transmitted in response to an operation for instructing the reproduction apparatus to start reproduction from a specified position in the content data by the user. A request communication unit that transmits information indicating that the content data is divided and transmitted to the playback device in response to the request or the seek request ;
In response to the request or the seek request received by the request communication unit, the data recorded in the recording unit among the content data is divided to create a plurality of partial data, and each of the plurality of partial data A division unit that creates size information and creates a plurality of divided contents including the partial data and the size information;
An adder that adds seekable range information indicating the range recorded in the recording unit of the content data to the size information when transmitting each divided content; and
After the request communication unit transmits information indicating that the content data is divided and transmitted to the reproduction device, the reproduction device sequentially includes the divided contents including the size information to which the seekable range information is added. A server comprising a transmitter for transmitting to
The playback device that transmits the request and the seek request to the server ,
A receiving unit that receives each of the divided contents transmitted from the server;
Reproducing unit for reproducing the partial data in which the receiver is included in each of the divided content received, and,
In accordance with the user's operation that designates the position within the range indicated by the seekable range information included in each divided content received by the reception unit, and instructs the start of reproduction from the position , A playback system comprising: a request creation unit that creates the seek request for requesting the server to transmit from the specified position within the range indicated by the seekable range information. Communication between the server and the playback device is performed by HTTP protocol,
The request is a request header;
Information indicating that the content data is divided and transmitted is included in the response header,
The partial data and the size information of the partial data to which the seekable range information is added are included in a response body,
2. The network system according to claim 1, wherein the seekable range information is described after a delimiter after the size information is described. A server for transmitting content data for reproduction to a reproduction device via a communication network,
An acquisition unit that partially acquires the content data from the outside multiple times ;
A recording unit that records a portion of the content data acquired by the acquisition unit each time ;
A request for requesting the recording unit to start transmission of the content data being recorded, which is transmitted via the communication network in response to an operation for instructing the user to specify the content data and to start the reproduction to the playback device . And a seek request for transmitting the content data from the position, which is transmitted in response to an operation for instructing the reproduction apparatus to start reproduction from a specified position in the content data by the user. A request communication unit that transmits information indicating that the content data is divided and transmitted to the playback device in response to the request or the seek request ;
In response to the request or the seek request received by the request communication unit, the data recorded in the recording unit among the content data is divided to create a plurality of partial data, and each of the plurality of partial data A division unit that creates size information and creates a plurality of divided contents each including the partial data and the size information;
An adder that adds seekable range information indicating a range recorded in the recording unit of the content data to the size information when transmitting each divided content;
After the request communication unit transmits information indicating that the content data is divided and transmitted to the reproduction device, the reproduction device sequentially includes the divided contents including the size information to which the seekable range information is added. A server comprising: a transmission unit that transmits to the server. A recording magnification that is a ratio of a time required for recording the content data portion recorded in the recording unit and a reproduction time for reproducing the content data portion recorded in the recording unit at 1 × speed And a transmission magnification which is a ratio of a time required for transmitting the partial data transmitted by the transmission unit to the reproduction device and a reproduction time when the partial data transmitted by the transmission unit to the reproduction device is reproduced at a single speed. A determination unit that determines a transmission interval of the seekable range information so that a small interval is obtained when the recording magnification is higher and a larger interval is obtained when the transmission magnification is higher. The server according to claim 3.   The server according to claim 3 or 4, wherein the seekable range information is described after a delimiter after the size information is described.   The server according to claim 5, wherein the delimiter is a semicolon. Depending on the operation of instructing the designation of the contents data of the user and the playback start and the request for requesting the start of transmission of the content data to the content data for playback to the server in the recording, to specify in said content data of the user A request transmission unit that transmits a seek request that requests transmission start of the content data from the position, which is transmitted in response to an operation for instructing reproduction start from the position ;
The partial data that is a part of the content data transmitted from the server in response to the request or the seek request and the seekable range information indicating the range recorded in the server among the content data are added. A receiving unit for receiving size information of the partial data,
A reproduction unit for reproducing the received partial data;
Specify the location within said seek range information received by the reception unit indicates, in accordance with the user's operation to instruct the start of reproduction from the position of the content data, indicated by the seek range information And a request creating unit that creates the seek request for requesting the server to transmit from the designated position within a range. A server that transmits content data for playback to a playback device via a communication network,
Obtaining the content data partially from the outside multiple times ;
Recording each time the acquired portion of the content data is acquired ;
A request for requesting the start of transmission of the content data being recorded, which is transmitted in response to a user operation instructing designation of the content data to the playback device and start of playback via the communication network, and Receiving a seek request for requesting the start of transmission of the content data from the position, which is transmitted in response to an operation for instructing the playback device to start playback from a specified position in the content data; Or in response to the seek request , transmitting information indicating that the content data is divided and transmitted to the playback device;
In response to the received request or the seek request, create a plurality of partial data by dividing the recorded data of the content data, create size information for each of the plurality of partial data, Creating a plurality of divided contents consisting of partial data and the size information;
A step of adding seekable range information indicating the recorded range of the content data to the size information when transmitting each divided content;
Transmitting information indicating that the content data is divided and transmitted to the playback device, and then sequentially transmitting the divided content including the size information to which the seekable range information is added to the playback device; ,
The playback device that transmits the request and the seek request to the server ,
Receiving each of the divided contents transmitted from the server;
Replaying the partial data included in each received divided content ;
Specify the location within said seek range information included in each content segment the received indicates, in accordance with the user's operation to instruct the start of reproduction from the position of the content data, the seek operation can Creating the seek request for requesting the server to transmit from the specified position within the range indicated by the range information.

Images