JP5154465B2 - File reading method, distribution server, program, and recording medium - Google Patents

Description

  The present invention relates to a file reading method, a distribution server, a program, and a recording medium, and more particularly, to an index file reading method in which encoding information of encoded video data is described.

Conventionally, when reproducing encoded video data using an index file in which encoding information of the encoded video data is described, the following method is basically used.
(1) The index file is stored on the hard disk.
(2) The index file describes a finely chopped playback time indicating when playback should be performed in units of one line, and is read from the hard disk in units of one line.
Note that an index file in which encoding information of encoded video data is described is described in, for example, Patent Document 1 below.

Japanese Patent Laid-Open No. 2001-45428

However, the conventional method described above has the following problems.
(1) Since the index file is read in finely chopped reproduction time units (one line unit) indicating when to reproduce, a large number of file reads occur.
(2) The processing speed is slow when reading from the hard disk.
(3) In jump playback, since the index file is read from the head, it takes time to search for the playback position.
The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to reproduce encoded video data using an index file in a file reading method and a distribution server. Another object of the present invention is to provide a technique capable of reducing the number of accesses to the hard disk, improving the processing speed, and improving the search processing speed of the playback position in the case of jump playback.
Another object of the present invention is to provide a program for causing a computer to execute the above-described reading method and a recording medium in which the program is described.
The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
(1) A receiving unit that receives a distribution request from a reproduction terminal, a transmission unit that transmits encoded video data that has been requested to be distributed to the reproduction terminal, and an index file that is encoded video data information are stored. Distribution for storing and distributing the encoded video data, comprising: an index file storage unit; an encoded video data storage unit storing encoded video data; and a temporary storage unit for temporarily storing the index file. In the server file reading method, when P and R are integers, the index file is composed of a plurality of lines, one frame is composed of P lines, one GOP is composed of R frames, and each line has a playback time. In step 1 for determining a distribution request from the playback terminal received by the receiver, and in step 1 When the determination result is playback from the beginning of the video, the index file of the encoded video data requested for distribution from the playback terminal is read from the index file storage unit in units of 1 GOP from the top, and the read index Corresponding to the step 3 for writing the file to the temporary storage unit, the step 4 for reading the written index file line by line from the temporary storage unit, and the playback time described for each line of the read index file And reading the encoded video data requested to be distributed from the playback terminal from the encoded video data storage unit, and transmitting the read encoded video data from the transmission unit to the playback terminal. Step 6 is included.

(2) In (1), when the judgment result in step 1 is jump playback, reading of the index file from the index file storage unit in units of 1 GOP is temporarily stopped instead of steps 2 to 3 And step 12 for determining how many seconds ahead or how many seconds before the jump playback time from the playback time of the index file read last in the pause and determining the index file read destination GOP. Reading the index file of the encoded video data requested to be distributed from the playback terminal from the index file storage unit in units of 1 GOP from the determined read destination GOP; and temporarily storing the read index file To write To perform and-up 14.
(3) In (1), when the judgment result in step 1 is temporarily stopped, reading the index file of the encoded video data from the index file storage unit in units of 1 GOP and reading from the temporary storage unit Step 21 for temporarily stopping reading of the index file line by line and reading of the encoded video data from the encoded video data storage unit, and when the judgment result in Step 1 is to resume reproduction, Reading the encoded video data from the index file storage unit in units of 1 GOP, reading the index file from the temporary storage unit line by line, and encoding from the encoded video data storage unit And step 22 for continuously reading the video data.

(4) In any one of (1) to (3), in the index file, one line is one NAL unit, and S is an integer, the one NAL unit is a fixed-length S byte, and one frame Is composed of P times 1 NAL unit.
(5) Moreover, this invention is a delivery server which performs the file reading method of the above-mentioned (1) thru | or (4).
(6) The present invention is a program for causing a computer to execute the file reading method of any one of (1) to (4) described above.
(7) Further, the present invention is a computer-readable recording medium on which the program (6) described above is recorded.

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
According to the present invention, when the encoded video data is reproduced using the index file, the number of accesses to the hard disk is reduced, the processing speed is improved, and the search processing speed of the reproduction position is increased in the case of jump reproduction. It becomes possible to improve.

It is a block diagram for demonstrating the schematic structure of the video delivery system with which the delivery server of the Example of this invention is applied, and the file reading method of the Example of this invention. It is a block diagram which shows schematic structure of the reading control part shown in FIG. It is a figure for demonstrating the outline | summary of the index file stored in the index file storage part of the delivery server of the Example of this invention. It is a flowchart which shows the process sequence of the file reading method of the Example of this invention. It is a figure for demonstrating an example of the more detailed process sequence of step 111 in the flowchart of FIG. It is a figure for demonstrating the other example of the more detailed process sequence of step 111 in the flowchart of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In all the drawings for explaining the embodiments, parts having the same functions are given the same reference numerals, and repeated explanation thereof is omitted.
FIG. 1 is a block diagram for explaining a schematic configuration of a video distribution system to which a distribution server of an embodiment of the present invention is applied and a file reading method of the embodiment of the present invention.
In FIG. 1, 10 is a distribution server that stores and distributes encoded video data, 20 is a reproduction terminal that requests the distribution server 10 to distribute encoded video data and reproduces the encoded video data, and 30 is a distribution server 10. This is a network connecting the playback terminal 20.
The distribution server 10 includes a receiving unit 11 that receives a distribution request from the playback terminal 20, a reading control unit 12, a temporary storage unit 13 that writes an index file, and an index that stores an index file that is encoded video data information. A file storage unit 14, an encoded video data storage unit 15 that stores encoded video data, and a transmission unit 16 that transmits the encoded video data to the reproduction terminal 20. Here, the reading control unit 12 controls the encoded video data storage unit 15, the index file storage unit 14, and the temporary storage unit 13.
The reproduction terminal 20 includes a transmission unit 21, a reception unit 22, a decoding unit 23, a reproduction request unit 24, and a display unit 25.
The user transmits a video distribution request from the reproduction request unit 24 of the reproduction terminal 20 to the distribution server 10 via the transmission unit 21, receives the encoded video data via the reception unit 22, decodes it at the decoding unit 23, and displays it. Playback is performed by the unit 25.
FIG. 2 is a block diagram showing a schematic configuration of the reading control unit 12 shown in FIG.
As shown in FIG. 2, the read control unit 12 includes a request determination unit 17 that performs distribution request determination, a file control unit 18 that performs read control of an index file, and a video data control unit that performs read control of encoded video data. 19.

The outline of the operation of the video distribution system of this embodiment will be described below with reference to FIGS.
The user transmits a video distribution request from the reproduction request unit 24 of the reproduction terminal 20 to the distribution server 10 via the transmission unit 21 ((1) in FIG. 1).
The receiving unit 11 of the distribution server 10 that has received the distribution request transmits the distribution request to the request determining unit 17 ((2) in FIG. 1), and the request determining unit 17 determines the content of the distribution request received from the receiving unit 11. The determination result is transmitted to the file control unit 18.
When the request determination result is playback from the beginning of the video, the file control unit 18 reads the index file of the encoded video data requested for distribution from the index file storage unit 14 in units of 1 GOP (L bytes) from the top. An instruction is issued ((4) in FIG. 1).
Further, the file control unit 18 issues a command to write the index file read in units of 1 GOP (L bytes) to the temporary storage unit 13 from the index file storage unit 14 ((5) in FIG. 1). Further, the file control unit 18 issues a command for reading the index file written in the temporary storage unit 13 line by line (N bytes) ((6) in FIG. 1) of the index file read by line (N bytes). A command for notifying the video data control unit 19 of the reproduction time described for each line is issued.
The video data control unit 19 issues a command to read out the encoded video data requested for distribution from the encoded video data storage unit 15 corresponding to the reproduction time received from the file control unit 18 ((7) in FIG. 1).
In addition, the video data control unit 19 issues a command to transmit the read encoded video data to the transmission unit 16 ((8) in FIG. 1). Then, the transmission unit 16 distributes the encoded video data to the reproduction terminal 20 ((9) in FIG. 1).
The encoded video data is received via the receiving unit 22 of the reproduction terminal 20, decoded by the decoding unit 23, and reproduced by the display unit 25 ((10) in FIG. 1).

Further, when the request determination result is temporarily stopped, the file control unit 18 issues a command to temporarily stop reading the index file from the index file storage unit 14 in units of 1 GOP (L bytes). In addition, the file control unit 18 issues a command to temporarily stop reading the index file for each row (N bytes) from the temporary storage unit 13.
Further, the file control unit 18 notifies the video data control unit 19 of a temporary stop. When the video data control unit 19 receives a pause from the file control unit 18, the video data control unit 19 issues a command to pause the reading of the encoded video data from the encoded video data storage unit 15.
In addition, when the request determination result is to resume reproduction, the file control unit 18 issues a command to resume and continue to read the index file in units of 1 GOP (L bytes) from the temporarily stopped index file storage unit 14. Further, the file control unit 18 issues a command to write the index file read from the index file storage unit 14 in units of 1 GOP (L bytes) to the temporary storage unit 13.
Further, the file control unit 18 issues a command to read the index file written in the temporary storage unit 13 one line (N bytes) and is described for each line of the index file read one line (N bytes). A command to notify the video data control unit 19 of the reproduction time is issued. The video data control unit 19 issues a command to read out the encoded video data requested for distribution from the encoded video data storage unit 15 corresponding to the reproduction time received from the file control unit 18. In addition, the video data control unit 19 issues a command to transmit the read encoded video data to the transmission unit 16. Then, the transmission unit 16 distributes the encoded video data to the reproduction terminal 20.

When the request determination result is jump playback, the file control unit 18 issues a command to temporarily stop reading the index file in units of 1 GOP (L bytes) from the index file storage unit 14. At the time of the temporary stop, the reproduction time of the index file last read in units of 1 GOP (L bytes) from the index file storage unit 14 is confirmed.
Further, the file control unit 18 compares the jump playback time with the playback time of the index file read last, and how many seconds ahead or how many seconds before the playback time of the index file read last. The file control unit 18 issues a command to read the index file from the index file storage unit 14 in units of 1 GOP (L bytes) from the determined destination.
Further, the file control unit 18 issues an instruction to write the index file read in units of 1 GOP (L bytes) from the index file storage unit 14 to the temporary storage unit 13. Further, the file control unit 18 issues a command to read the index file written in the temporary storage unit 13 one line (N bytes) and is described for each line of the index file read one line (N bytes). A command to notify the video data control unit 19 of the reproduction time is issued.
The video data control unit 19 issues a command to read out the encoded video data requested for distribution from the encoded video data storage unit 15 corresponding to the reproduction time received from the file control unit 18.

Hereinafter, the operation of the reading control unit 12 will be described in detail with reference to FIG.
(1) The request determination unit 17 receives the distribution request and determines the content of the distribution request ((1) in FIG. 2).
(2) The request determination unit 17 notifies the file control unit 18 of the determination result ((2) in FIG. 2).
(3) When the file control unit 18 receives a playback distribution request from the beginning of the video, the file control unit 18 selects the index file of the encoded video data requested for distribution from the index file storage unit 14 from the top by 1 GOP (L bytes). A command to read in units is issued ((3) in FIG. 2).
(4) The file control unit 18 issues a command to write the index file read from the index file storage unit 14 to the temporary storage unit 13 in units of 1 GOP (L bytes) ((4) in FIG. 2).
(5) The file control unit 18 reads the index file from the temporary storage unit 13 in units of one line (N bytes), confirms the reproduction time described for each line, and confirms the confirmation with the video data control unit 19. A command for notifying the playback time is issued ((5) in FIG. 2).
(6) The video data control unit 19 issues a command to read out the encoded video data requested for distribution from the encoded video data storage unit 15 corresponding to the playback time received from the file control unit 18 (( 6)).
(7) The video data control unit 19 issues a command to transmit the read encoded video data to the transmission unit 16 ((7) in FIG. 2).
(8) When receiving the jump playback distribution request, the file control unit 18 issues an index file read pause command from the index file storage unit 14 and from the playback time of the index file read last in this pause. How many seconds ahead or how many seconds before the jump playback time is determined ((8) in FIG. 2).
(9) When the determination result notified from the request determination unit 17 is temporarily stopped, the file control unit 18 issues an instruction to temporarily stop reading from the temporary storage unit 13 and the index file storage unit 14 (FIG. 2). (9)).
(10) When the distribution request is paused, the file control unit 18 notifies the video data control unit 19 of suspension ((10) in FIG. 2).
(11) When the distribution request is paused, the video data control unit 19 issues a pause command to read out the encoded video data from the encoded video data storage unit 15 ((11) in FIG. 2).

FIG. 3 is a diagram for explaining an overview of the index file stored in the index file storage unit of the distribution server according to the present embodiment.
In this embodiment, the encoded video data information is an index file.
The index file describes encoding information of the encoded video data such as reproduction time information of the encoded video data.
The index file of the present embodiment has the following configuration.
(1) The index file is composed of a plurality of lines, but one line is a NAL unit.
1 NAL unit (Network Abstraction Layer unit) is used to divide and identify data, and it can be applied flexibly to various uses such as RTP (Real-time Transport Protocol) packet. It can be done.
(2) One line has a fixed length of N (N is an integer) bytes.
(3) A playback time indicating when playback should be performed for each line is always described.
(4) NALU × X (X is an integer) row is one frame. Therefore, the number of bytes per frame is N bytes × X rows = M bytes.
(5) The index file is read from the index file storage unit 14 in units of 1 GOP (L bytes). One GOP (Group Of Pictures) is 15 frames (1 GOP = 15 frames = 0.5 seconds), and 15 × (1 NALU × X rows) = every Y row, that is, 15 × (N bytes × X rows) = L The index file is read from the index file storage unit 14 for each byte. In this embodiment, 1 GOP is 15 frames, but 1 GOP is not necessarily 15 frames, and can be set to an arbitrary value.

FIG. 4 is a flowchart showing the processing procedure of the file reading method of this embodiment.
[Play from the beginning of the video data]
In step 101, a distribution request is transmitted from the transmission unit 21 of the playback terminal 20 to the distribution server 10.
In step 102, the receiving unit 11 of the distribution server 10 receives the distribution request, and the receiving unit 11 transmits the distribution request to the request determination unit 17.
In step 103, the request determination unit 17 determines the distribution request content received from the reception unit 11 and notifies the file control unit 18 of the determination result.
If the request determination result is playback from the top of the video in step 104, the process proceeds to step 105, where the file control unit 18 sends the index file of the encoded video data requested for distribution from the index file storage unit 14 to the top. In step 106, the file control unit 18 issues an instruction to write the index file read in 1 GOP (L byte) units to the temporary storage unit 13.
In step 107, the file control unit 18 issues a command to read the index file written in the temporary storage unit 13 one line (N bytes) at a time, and is described for each line of the index file read one line (N bytes). The playback time is confirmed, and a command for notifying the video data control unit 19 of the confirmed playback time is issued.
In step 108, the video data control unit 19 issues a command to read out the encoded video data requested for distribution from the encoded video data storage unit 15 corresponding to the playback time received from the file control unit 18. A command for transmitting the encoded video data to the transmitter 16 is issued.
In step 109, the encoded video data is distributed from the transmission unit 16 to the playback terminal 20.
In step 110, the receiving unit 22 of the playback terminal 20 receives the encoded video data, decodes it with the decoding unit 23, and plays it back with the display unit 25.

[pause]
In step 104, if the request determination result is temporary stop, the process proceeds to step 113, and the file control unit 18 issues an instruction to temporarily stop reading the index file from the index file storage unit 14 in units of 1 GOP (L bytes). put out.
In addition, the file control unit 18 issues a command to temporarily stop reading the index file for each row (N bytes) from the temporary storage unit 13. Further, the file control unit 18 notifies the video data control unit 19 of a temporary stop.
When the video data control unit 19 receives a pause from the file control unit 18, the video data control unit 19 issues a command to pause the reading of the encoded video data from the encoded video data storage unit 15.

[Resume playback]
If it is determined in step 104 that the request determination result is resumption of playback, the process proceeds to step 105, where the file control unit 18 resumes reading the index file in units of 1 GOP (L bytes) from the temporarily stopped index file storage unit 14. In step 106, the file control unit 18 issues an instruction to write the index file read in units of 1 GOP (L bytes) to the temporary storage unit 13.
In step 107, the file control unit 18 issues a command to read the index file written in the temporary storage unit 13 one line (N bytes) at a time, and is described for each line of the index file read one line (N bytes). The playback time is confirmed, and a command for notifying the video data control unit 19 of the confirmed playback time is issued.
In step 108, the video data control unit 19 issues a command to read out the encoded video data requested for distribution from the encoded video data storage unit 15 corresponding to the reproduction time received from the file control unit 18, and further transmits the transmission unit. A command for transmitting the encoded video data to 16 is issued.
In step 109, the encoded video data is distributed from the transmission unit 16 to the playback terminal 20.
In step 110, the receiving unit 22 of the playback terminal 20 receives the encoded video data, decodes it with the decoding unit 23, and plays it back with the display unit 25.

[Jump playback]
If the request determination result is jump playback in step 104, the process proceeds to step 111, where the file control unit 18 issues a command to temporarily stop reading the index file in units of 1 GOP (L bytes) from the index file storage unit 14, In step 112, the file control unit 18 confirms the reproduction time of the index file last read in units of 1 GOP (L bytes) from the index file storage unit 14 at the time of the temporary stop.
Further, the jump playback time is compared with the playback time of the index file read last, and the jump playback time how many seconds ahead or how many seconds ago is calculated from the playback time of the index file read last.
In step 105, the file control unit 18 issues a command for reading the index file from the index file storage unit 14 in units of 1 GOP (L bytes) from the determined destination.
In step 106, the file control unit 18 issues a command to write the index file read from the index file storage unit 14 in units of 1 GOP (L bytes) to the temporary storage unit 13.
In step 107, the file control unit 18 issues a command to read the index file written in the temporary storage unit 13 one line (N bytes) at a time, and is described for each line of the index file read one line (N bytes). The playback time is confirmed, and a command for notifying the video data control unit 19 of the confirmed playback time is issued.
In step 108, the video data control unit 19 issues a command to read out the encoded video data requested to be distributed from the encoded video data storage unit 15 corresponding to the playback time received from the file control unit 18, and the read code A command to transmit the converted video data to the transmission unit 16 is issued.
In step 109, the encoded video data is distributed from the transmission unit 16 to the playback terminal 20.
In step 110, the receiving unit 22 of the playback terminal 20 receives the encoded video data, decodes it with the decoding unit 23, and plays it back with the display unit 25.

In the case of jump playback, the file control unit 18 of the read control unit 12 temporarily stops reading the index file from the index file storage unit 14 in units of 1 GOP (L bytes). The reproduction time of the index file read from the index file storage unit 14 is confirmed in units of (L bytes). Further, the file control unit 18 determines the index file read destination GOP based on the confirmed reproduction time.
FIG. 5 is a diagram for explaining an example of a more detailed processing procedure of step 111 in the flowchart of FIG.
As shown in FIG. 5, when the jump playback destination is after the current playback time, for example, when paused, the last playback time read in units of 1 GOP (L bytes) is 10 seconds, and the jump playback time is 40 seconds. If the two are compared, the difference from the playback time of the last read index file is found to be 40 seconds-10 seconds = 30 seconds ahead, 30 seconds × 2 GOP = 60 GOP ahead.
The file control unit 18 reads the index file from the index file storage unit 14 in units of 1 GOP (L bytes) from the 60 GOP (60 GOP × L bytes) counting from the 21st GOP after the 10 second (20 GOP).

FIG. 6 is a diagram for explaining another example of a more detailed processing procedure of step 111 in the flowchart of FIG.
As shown in FIG. 6, when the jump playback destination returns from the current playback point, for example, when the playback time of the index file read last when paused is 30 seconds and the jump playback time is 10 seconds, the two are compared. Then, it can be seen that the amount returned from the reproduction time of the last read index file is 30 seconds-10 seconds = 20 seconds and 20 seconds × 2 GOP = 40 GOP.
The read control unit 12 returns 40 GOP (40 GOP × L bytes) from the 59 GOP immediately before 30 seconds (60 GOP), and returns the index file in units of 1 GOP (L bytes) from the returned 20 GOP. 14 to read.
As described above, according to the present embodiment, the reading unit of the index file from the hard disk is set to 1 GOP (= 15 frames = 0.5 seconds = L bytes), and reading is performed in units of 1 GOP (L bytes). The number of accesses to the slow hard disk decreases. In addition, since the index file is read in units of lines from the temporary storage unit 13, the processing speed can be increased.
Further, even when the playback jumps, it is easy to know how many GOP destinations or before GOPs can be read to obtain the requested jump position information, and the playback position search processing speed can be improved. In the above description, 1 GOP is 15 frames, but 1 GOP is not necessarily 15 frames.
The distribution server of the present invention can also be executed by a computer. In this case, the file reading method of the present invention is performed by the computer executing a program stored in a hard disk or the like in the computer. This program is supplied by CD-ROM or download via a network.
As mentioned above, the invention made by the present inventor has been specifically described based on the above embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Of course.

DESCRIPTION OF SYMBOLS 10 Distribution server 11 Receiving part 12 Reading control part 13 Temporary storage part 14 Index file storage part 15 Encoded video data storage part 16 Transmission part 17 Request judgment part 18 File control part 19 Video data control part 20 Playback terminal 21 Transmission part 22 Reception Unit 23 decoding unit 24 reproduction request unit 25 display unit 30 network

Claims (10)

A receiving unit for receiving a distribution request from the playback terminal;
A transmitting unit that transmits the encoded video data requested to be distributed to the playback terminal;
An index file storage unit in which an index file that is encoded video data information is stored;
An encoded video data storage unit in which encoded video data is stored;
A temporary storage unit for temporarily storing the index file,
A file reading method of a distribution server for storing and distributing the encoded video data,
When P and R are integers, the index file is composed of a plurality of lines, one frame is composed of P lines, one GOP is composed of R frames, and each line describes a playback time,
Determining a delivery request from the playback terminal received by the receiver;
A step 2 of reading an index file of encoded video data requested for distribution from the playback terminal from the index file storage unit in units of 1 GOP when the judgment result in the step 1 is playback from the head of the video; ,
Writing the read index file into the temporary storage unit; and
Step 4 of reading the written index file line by line from the temporary storage unit;
Step 5 of reading out the encoded video data requested to be distributed from the playback terminal from the encoded video data storage unit corresponding to the playback time described for each line of the read index file;
And a step of transmitting the read encoded video data from the transmission unit to the playback terminal. If the determination result in step 1 is jump playback, step 11 for temporarily stopping reading the index file from the index file storage unit in units of 1 GOP instead of steps 2 to 3;
A step 12 of determining how many seconds or how many seconds before the jump playback time from the playback time of the index file read last in the pause, and determining a read destination GOP of the index file;
Reading the index file of the encoded video data requested to be distributed from the playback terminal from the index file storage unit in units of 1 GOP from the determined read destination GOP;
The file reading method according to claim 1, wherein the step 14 of writing the read index file to the temporary storage unit is executed. When the determination result in step 1 is temporary stop, reading the index file of the encoded video data from the index file storage unit in units of 1 GOP, and for each row of the index file from the temporary storage unit Reading and temporarily stopping the reading of the encoded video data from the encoded video data storage unit,
If the determination result in step 1 is to resume playback, reading the index file of the encoded video data from the index file storage unit in units of 1 GOP, and one line of the index file from the temporary storage unit The file reading method according to claim 1, further comprising a step of reading and executing step 22 of continuously reading the encoded video data from the encoded video data storage unit. In the index file, one line is one NAL unit,
When S is an integer, the 1 NAL unit is a fixed-length S byte,
The file reading method according to any one of claims 1 to 3, wherein one frame is configured by P times one NAL unit. A receiving unit for receiving a distribution request from the playback terminal;
A transmitting unit that transmits the encoded video data requested to be distributed to the playback terminal;
An index file storage unit in which an index file that is encoded video data information is stored;
An encoded video data storage unit in which encoded video data is stored;
A temporary storage unit for temporarily storing the index file;
A reading control unit,
A distribution server for storing and distributing the encoded video data,
When P and R are integers, the index file is composed of a plurality of lines, one frame is composed of P lines, one GOP is composed of R frames, and each line describes a playback time,
The read control unit includes a request determination unit,
A file control unit;
A video data control unit,
The request determination unit determines a distribution request from the playback terminal received by the reception unit, notifies the determination result to the file control unit,
When the distribution request from the playback terminal received by the reception unit is playback from the beginning of the video, the file control unit reads the index file of the encoded video data requested from the playback terminal by 1 GOP from the top. A function 11 for reading from the index file storage unit in units and writing the index file read in units of 1 GOP to the temporary storage unit;
A function 12 for reading the index file written in the temporary storage unit line by line and notifying the video data control means of the reproduction time described for each line;
The video data control unit reads out from the encoded video data storage unit the encoded video data requested to be distributed from the playback terminal corresponding to the playback time received from the file control unit;
A distribution server comprising a function 22 for transmitting the read encoded video data to the transmission unit. The file control unit, when the distribution request received from the playback terminal received by the reception unit is jump playback, a function 13 for temporarily stopping reading of the index file from the index file storage unit in units of 1 GOP;
A function 14 for determining how many seconds ahead or how many seconds before the jump playback time from the playback time of the index file read last in the pause and determining the index file read destination GOP;
The function 11 of the file control unit reads the index file of the encoded video data requested to be distributed from the playback terminal from the index file storage unit in units of 1 GOP from the determined read destination GOP. 6. The distribution server according to claim 5, wherein an index file is written in the temporary storage unit. When the distribution request from the playback terminal received by the reception unit is temporarily stopped, the file control unit reads the index file of the encoded video data from the index file storage unit in units of 1 GOP, A function 15 for stopping reading out the index file line by line from the storage unit;
When the distribution request from the playback terminal received by the receiving unit is to resume playback, reading the index file of the encoded video data from the index file storage unit in 1 GOP units and the index from the temporary storage unit A function 16 for continuously reading the file line by line;
The video data control unit, when a distribution request from the playback terminal received by the reception unit is temporarily stopped, a function 23 for temporarily stopping reading of the encoded video data from the encoded video data storage unit;
And a function 24 for continuously reading out the encoded video data from the encoded video data storage unit when the distribution request received from the playback terminal received by the receiving unit is to resume playback. The distribution server according to claim 5. In the index file, one line is one NAL unit,
When S is an integer, the 1 NAL unit is a fixed-length S byte,
The distribution server according to any one of claims 5 to 7, wherein one frame is configured by P times one NAL unit.   The program for making a computer perform the file reading method of any one of Claim 1 thru | or 4.   A computer-readable recording medium on which the program according to claim 9 is recorded.

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