JPH07284085A - System for reading realtime data - Google Patents

Abstract

PURPOSE:To obtain a realtime data reading system whereby data is read till time required for reproduction, buffer capacitance for temporarily storing read data is no increased, the dispersion of an interval receiving read data is restricted and transmission fluctuation is reduced. CONSTITUTION:Animation data reading control parts 2a and 2b control delay for reading animation frame data at every animation storing part, consider time required for frame data and delay time for reading, requests frame data reading to the respective animation storing parts 1a, 1b and 1c and reproduce a received animation. At this time, the control parts 2a and 2b measures delay time from the request till data reception and updates controlled delay.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a real-time data reading system for accumulating real-time data such as voice and moving images and reading and reproducing the accumulated data.

[0002]

2. Description of the Related Art In recent years, real-time data such as audio and moving images are accumulated on a hard disk such as a personal computer and a workstation, and audio and moving image data are read out from other personal computers and workstations and reproduced, and an interactive television. Video on demand, which centrally manages video information as a service for multiple users and simultaneously accesses that information (for example, Nikkei Communication 1993.2.15 No.144 pp.
38-55).

In order to realize these, it is necessary to read the real-time data by the time required to reproduce the accumulated real-time data. For example, in reproducing a standard moving image, information of 30 frames per second is required.

[0004]

However, from the request of reading the data to the reception of the data,
There is a delay such as a time for searching and reading from a hard disk where data is stored, a time for transferring data, and the like. This delay varies depending on the load such as the number of reproductions. Therefore, there arises a problem that data cannot be read by the time required for reproduction. Therefore, in order to prevent the problem due to the fluctuation of the delay time, there is a problem that a large capacity buffer memory must be provided.

As a method of storing one real-time data, a method of storing in one place instead of one place has been announced (for example, Tanaka, Shimojo, “Current state of moving image database technology and Future ”, IPSJ Advanced Database Symposium '9
3 papers, December 1993 pp.55-62). However,
When data is stored by such a method, the delay time may differ depending on each storage location, data cannot be read by the time required for reproduction, or there is variation in the interval at which the read data is received, causing transmission fluctuations. There is.

The present invention takes into consideration such a problem at the time of reading conventional real-time data, and allows the data to be read by the time required for reproduction without increasing the buffer capacity for temporarily storing the read data. An object of the present invention is to provide a real-time data reading system capable of suppressing fluctuations in transmission data receiving intervals and suppressing transmission fluctuations.

[0007]

The present invention according to claim 1 relates to one or a plurality of data accumulating units for accumulating data such as moving images and audio by dividing it into units, and the data accumulating unit. In a real-time data read system including one or a plurality of data read control units for making a data read request and outputting the read data at a predetermined timing, the data read control unit sets a data storage unit to a data storage unit. Read request sending means for making a read request, data receiving means for receiving the data read by the read request, and delay managing means for measuring and managing the delay time from the read request to the data reception The read request transmission means is controlled by the scheduled time and delay management means for outputting the reception data at a predetermined timing. Based on the delay time, a real-time data readout system for reading request.

According to the third aspect of the present invention, one or a plurality of data accumulating units for dividing and accumulating data such as moving images and voices for each unit, and making a data read request to the data accumulating unit. In a real-time data read system including one or a plurality of data read control units that output read data at a predetermined timing, a data storage unit estimates a delay time that occurs based on a predetermined delay factor, The data read control unit has a delay information transmission unit that transmits the delay information of the estimated delay time to the data read control unit, and the data read control unit and a read request transmission unit that makes a data read request to the data storage unit, and A data receiving means for receiving the data read by the read request and the delay information transmitted from the delay information transmitting section, and receiving the received delay information. And a delay information reception management unit that sets a delay time of the delay information, wherein the read request transmission unit is configured to output the received data at a predetermined timing based on the scheduled time and the delay time set in the delay information reception management unit. , A real-time data read system for making a read request.

[0009]

According to the present invention of claim 1, the read request sending means issues a read request to the data accumulating section based on the scheduled time at which the received data should be output at a predetermined timing and the delay time managed by the delay managing means. The delay management unit measures and manages the delay time from the read request to the data reception unit receiving the data.

According to the third aspect of the present invention, the delay information transmitting section of the data storage section estimates the delay time generated based on a predetermined delay factor, and the delay information of the estimated delay time is sent to the data read control section. The delay information reception management unit of the data read control unit receives the delay information transmitted from the delay information transmission unit, sets the delay time of the received delay information, and the read request transmission unit transmits the received data. A read request is issued based on the scheduled time to be output at a predetermined timing and the delay time set in the delay information reception management unit.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing its embodiments. (Embodiment 1) FIG. 1 is a block diagram showing the configuration of a moving image data reading system according to Embodiment 1 of the present invention. In FIG. 1, 1a, 1b, and 1c are moving image storage units which are data storage units, and record data of a single or a plurality of moving images by dividing them into frame units. 2a,
Reference numeral 2b denotes a moving image data read control unit that is a data read control unit, and based on moving image sequence data that records address information in which moving image frame data is stored according to the moving image frame order, moving image frame data To read and play. Reference numeral 3 denotes a data transmission path, which performs data transmission between the moving image storage units 1a, 1b, 1c and the moving image data read control units 2a, 2b.

FIG. 2 shows the internal structure of the moving picture data read control unit 2a shown in FIG. 1 described above (2b has the same structure).
It is the block diagram shown about. In FIG. 2, 4
Is a sequence data storage unit, which stores sequence data of a moving image to be reproduced. Reference numeral 5 denotes a read request transmission unit, which is a read request transmission unit, and transmits a frame data read request to the moving image storage units 1a, 1b, and 1c according to the sequence data of the sequence data storage unit 4. Reference numeral 6 denotes a delay management unit which is a delay management means, and measures and manages the delay time from the transmission of the frame data read request to the actual reception of the frame data. Reference numeral 7 is a frame data receiving section which is a data receiving means, and receives the frame data from the moving image storage sections 1a, 1b and 1c and temporarily stores them.

Actually, in addition to this, various components such as a function of reproducing a moving image from frame data of a moving image, a function of performing an interface process with a user, a function of processing a communication interface with the data transmission path 3 are required. But,
Since it is not the main purpose of the present invention, its explanation is omitted.

Next, the operation of the moving picture data reading system configured as described above will be described with reference to the drawings.

FIG. 3 is a diagram showing an example of sequence data stored in the sequence data storage unit 4. In this example, the sequence number of the moving image, the ID of the moving image storage unit that stores the frame data, and the file ID are managed.

FIG. 4 is a diagram showing an example of a control sequence of the moving image data read control unit 2a and the moving image storage units 1a, 1b, 1c. In this example, the moving image data read control unit 2a sends a "reading request" to the moving image storage units 1a, 1b, 1c by designating the moving image storage unit ID and the file ID.
It indicates that the requested “frame data” is received after a delay D1 or D2 in response to the request. Also,
The received frame data is periodically output to the outside.

Now, when the user makes a reproduction request for a moving image, the read request transmission unit 5 causes the sequence data storage unit 4 to operate.
A "read request" is sent to the moving image storage units 1a, 1b, 1c through the data transmission line 3 in accordance with the sequence data of 1. The transmission timing is calculated so as to be in time between the time required for the requested frame data and the required time calculated from the delay time managed by the delay management unit 6. Next, the moving image storage units 1a, 1b, 1c receive the “read request” and transmit the frame data corresponding to the “read request” to the moving image data read control unit 2a. Then, the frame data receiving unit 7 receives the frame data and stores the frame data until the frame data is needed for moving image reproduction. At this time, the delay management unit 6 measures the delay from the transmission of the "read request" to the reception of the frame data, and sets the delay time for the "read request" to be transmitted next.

In the example of FIG. 4, A1 of the frame data of the moving image
When 01 is read, the delay managed by the delay management unit 6 is D1, and the "read request" of A101 is sent before the delay D1 from the time when A101 of the frame data is required. Next, A101 of the frame data corresponding to the read request
Is received and the delay time from sending the "read request" is D1
If so, the delay management unit 6 manages the delay as D1 since there is no change in the delay. Similarly, for the next required A102 of the frame data, the “read request” of A102 before the delay D1 from the time when the A102 of the frame data is required.
Is sent.

Thereafter, if the delay varies due to an increase in the system load, the delay management unit 6 delays the time from sending the read request to receiving the frame data corresponding to the read request. Is measured differently from the delay D1, and the delay management unit 6 changes the value of the delay time to be managed to the newly measured delay time value. At this time, if a delay variation occurs such that the next read request is sent until the frame data is received, in other words, a new delay time is measured, the output timing of the frame data cannot be met in time, so the frame data Will be discarded, but the next read request will be sent with a new delay. For example, as shown in FIG. 4, if the delay D1 is changed to the delay D2 before reading the frame data A1001, the delay managed by the delay management unit 6 becomes D2 when the frame data A1001 is read. Therefore, the A1001 “read request” is sent before the delay D2 from the time when the frame data A1001 is required. Then, for the frame data A1002, the delay D2
Before that, the "read request" of A1002 is transmitted.

In this way, the delay time from the read request to the reception of the frame data is measured and managed, and the read request is sent in consideration of the delay time to temporarily store the frame data. The frame data can be prepared up to the required time without increasing the buffer capacity.

In the first embodiment, the moving picture data is divided in units of frames, but it is also possible to divide a plurality of frames together or to divide one frame further.

Further, in the above-mentioned first embodiment, the moving image storage section is divided into three.
The number of moving image data read control units is two, but the number is not limited to this, and the number can be increased or decreased.

Further, in the first embodiment, the moving picture sequence data is assumed to exist in the moving picture data read control section, but instead of this, it may be acquired from the outside if necessary.

In the first embodiment, the "read request" is sent so that the frame data is received immediately before the frame data is needed. However, the present invention is not limited to this, and the buffer for temporarily storing the frame data is provided. It may be configured to allow a capacity and receive one frame or a plurality of frames in advance. In that case, it is possible to prevent the data from being discarded due to the fluctuation of the delay. (Embodiment 2) Next, a moving image data reading system according to Embodiment 2 of the present invention will be described.

The block diagram showing the configuration of the moving picture data reading system according to the second embodiment of the present invention is the same as FIG. 1 of the first embodiment. The block diagram showing the internal configuration of the moving image data read control units 2a and 2b of the second embodiment is the same as that of FIG. 2 of the first embodiment. However, the delay management unit 6 manages the delay time for each of the moving image storage units 1a, 1b, 1c, and the read request transmission unit 5 transmits a "read request" based on the delay time of each moving image storage unit.

Actually, besides this, various components such as a function of converting a moving image into frame data, a function of performing an interface process with a user, a function of processing a communication interface with the data transmission line 3 are required. Since it is not the main purpose of the present invention, its explanation is omitted.

Next, the operation of the moving picture data reading system configured as described above will be described with reference to the drawings.

In the second embodiment, an example of the sequence data stored in the sequence data storage unit 4 is the same as that of the first embodiment shown in FIG.

FIG. 5 is a diagram showing an example of the delay information managed by the delay management unit 6. As shown in FIG. 5, in this example, the delays Da, Db, and Dc are managed corresponding to the moving image storage units 1a, 1b, and 1c, respectively.

FIG. 6 is a diagram showing an example of a control sequence of the moving image data read control unit 2a and the moving image storage units 1a, 1b, 1c. In this example, the moving image data read control unit 2a sends a "reading request" to the moving image storage units 1a, 1b, 1c by designating the moving image storage unit ID and the file ID.
As a response, it indicates that the requested "frame data" is received after the delays Da, Db, and Dc. Further, the received frame data is periodically output to the outside.

Now, when a user makes a reproduction request for a moving image, the read request transmission unit 5 causes the sequence data storage unit 4 to operate.
A "read request" is sent to the moving image storage units 1a, 1b, 1c through the data transmission line 3 in accordance with the sequence data of 1. The transmission timing is calculated so as to meet the required time by calculating from the time required for the requested frame data and the delay time for each moving image storage unit managed by the delay management unit 6. Next, the moving image storage units 1a, 1b, 1
The c receives the "read request" and transmits the corresponding frame data to the moving image data read control unit 2a. Then, the frame data receiving unit 7 receives the frame data and stores the frame data until the frame data is needed for moving image reproduction. The delay management unit 6 measures the delay from the transmission of the “read request” to the reception of the frame data, and updates the delay time of each corresponding moving image storage unit.

In the example of FIG. 6, A1 of the frame data of the moving image
When 01 is read from the moving image storage unit 1a, the delay management unit 6
The delay of the moving picture storage unit 1a managed by is Da, and A1 of the frame data is required before the delay Da from the time when A101 of the frame data is required.
Send the 01 read request. Then, the moving image storage unit 1b
Since the delay Db of A is large and the A102 “read request” of the frame data is sent after receiving the A101 of the frame data, it is not enough in time to continue.
Send a "read request". After that, A1 of frame data
01 is received and frame data A102 is received. Regarding the frame data A103, since the delay Dc of the moving image storage unit 1c is small, a "read request" is sent after receiving the frame data A102, and the frame data A103 is received.

After that, when there is a change in the delay time of each moving picture storage unit measured by the delay management unit 6, the timing of the read request is calculated using the new measured delay time.

As described above, the delay time from the read request to the reception of the frame data is measured and managed for each moving image storage unit, and the request is transmitted in consideration of the delay time, whereby the frame data is It is possible to prepare the frame data by the time when it is necessary without increasing the buffer capacity for temporarily storing. Further, it is possible to reduce the transmission fluctuation on the data transmission path by keeping the interval of receiving the frame data constant.

In the second embodiment, the moving image data is divided on a frame-by-frame basis, but it is also possible to divide a plurality of frames together or to divide one frame further.

In the second embodiment, the moving picture storage unit is
The number of moving image data read control units is two, but the number is not limited to this, and the number can be increased or decreased.

In the second embodiment, the moving picture sequence data is assumed to exist in the moving picture data read control section, but instead of this, it may be acquired from the outside as necessary.

In the second embodiment, the "read request" is sent so that the frame data is received immediately before the frame data is needed, but there is a margin in the buffer capacity for temporarily storing the frame data. However, it may be configured to receive one or more frames in advance. In that case, it is possible to prevent the data from being discarded due to the fluctuation of the delay. (Third Embodiment) Next, a moving image data reading system according to a third embodiment of the present invention will be described.

The block diagram showing the configuration of the moving picture data reading system of the third embodiment is the same as that of FIG. 1 of the first embodiment.

FIG. 7 shows a moving image data read control unit 2a,
It is the block diagram shown about the internal structure of 2b. Figure 7
In the figure, 8 is a sequence data storage unit, which stores sequence data of a moving image to be reproduced. A read request transmission unit 9 sends a frame data read request to the moving image storage units 1a, 1b, and 1c according to the sequence data of the sequence data storage unit 8. 10
Is a delay information reception management unit, which is a moving image storage unit 1a, 1
It receives the delay information from b, 1c and manages the delay time used when sending the frame data read request. 11
Is a frame data receiving unit and is a moving image storage unit 1a, 1
The frame data from b, 1c are received and temporarily stored.

FIG. 8 is a block diagram showing the internal structure of the moving picture storage units 1a, 1b, 1c. Reference numeral 12 denotes a moving picture management unit, which stores and manages moving picture frame data. A read request receiving unit 13 receives a frame data read request and reads frame data from the moving image management unit 12. 14 is a delay information transmission unit,
The delay time is estimated by the number of read requests accumulated in the read request receiving unit, and the moving image data read control unit 2
The delay information of the estimated delay time is transmitted to a and 2b. 1
A frame data transmission unit 5 transmits the frame data read from the moving image management unit 12 to the moving image data read control units 2a and 2b.

Actually, in addition to this, various components such as a function of converting a moving image into frame data, a function of performing an interface process with a user, a function of processing a communication interface with the data transmission path 3 are required. Since it is not the main purpose of the present invention, its explanation is omitted.

Next, the operation of the moving image data reading system configured as described above will be described with reference to the drawings.

In the third embodiment, an example of the sequence data stored in the sequence data storage section 8 is the same as that of the first embodiment shown in FIG. An example of the delay information managed by the delay management unit 6 is the same as that in FIG. 5 of the second embodiment.

FIG. 9 is a diagram showing an example of a control sequence of the moving image data read control unit 2a and the moving image storage units 1a, 1b, 1c. In this example, the moving image data read control unit 2a sends a "reading request" to the moving image storage units 1a, 1b, 1c by designating the moving image storage unit ID and the file ID.
As a response thereto, it indicates that the requested “frame data” is received after the delays Da, Db, Dc, and Dc ′ (Dc ′ represents the changed delay in the moving image storage unit 1c). The received frame data is periodically output to the outside. Further, the moving image storage unit 1c transmits a "delay notification" with a new delay Dc 'added to the moving image data read control unit 2a.

Now, when a user makes a reproduction request for a moving image, the read request transmission unit 9 causes the sequence data storage unit 8 to operate.
A "read request" is sent to the moving image storage units 1a, 1b, 1c through the data transmission line 3 in accordance with the sequence data of 1. The transmission timing is calculated from the time required for the requested frame data and the delay time for each moving image storage unit managed by the delay information reception management unit 10 in time to the required time. Read request receiver 1
3 receives the “read request”, reads the corresponding frame data from the moving image management unit 12, and the frame data transmission unit 15 transmits the read frame data to the frame data reception unit 11. The frame data receiving unit 11 receives the frame data and stores the frame data until the frame data is needed for reproducing the moving image. Delay information transmitter 14
“Read request” accumulated in the read request receiving unit 13
The delay time required to read the frame data is calculated (estimated) from the number of frames, and if there is a variation in the delay time, a “delay notification” is transmitted to the delay information reception management unit 10. The delay information reception management unit 10 manages the delay time included in the received “delay notification”.

In the example of FIG. 9, the moving picture data read control unit 2a reads the moving picture frame data A101, A102, and A103 from the moving picture storage units 1a, 1b, and 1c from the time when each frame data is needed. The "read request" is transmitted before the delays Da, Db, Dc of the moving image storage units 1a, 1b, 1c managed by the delay management unit 6. Then, the frame data corresponding to each read request is received. Video storage unit 1
“Read request” is sent to c, and the read request receiving unit 13
When the delay calculated in the moving image storage unit 1c changes after the read request is received, the delay information transmitting unit 14 sends a "delay notification" including the new delay time Dc 'to the moving image data read control unit. 2a. After that, when reading A104 and A105 of the frame data from the moving image storage units 1a and 1b, the "read request" is sent using the same delays Da and Db as before. On the other hand, A106 of frame data
Is read from the moving image storage unit 1c, a "read request" is transmitted using the delay Dc 'notified earlier.

As described above, the delay required for reading the frame data is determined on the side of each moving image storage unit and notified to the moving image data read control unit, and the request is transmitted in consideration of the delay, so that the frame data is temporarily stored. It is possible to prepare the frame data by the time when it is necessary without increasing the buffer capacity for storing the data. Further, it is possible to reduce the transmission fluctuation on the data transmission path by keeping the interval of receiving the frame data constant. Further, it is possible to know in advance the fluctuation of the delay required for reading.

Although the moving picture data is divided in units of frames in the third embodiment, it is possible to divide a plurality of frames together or to divide one frame further.

In the third embodiment, the moving picture storage unit is
The number of moving image data read control units is two, but the number is not limited to this, and the number can be increased or decreased.

Further, in the third embodiment, the sequence data of the moving image is assumed to exist in the moving image data read control section, but instead of this, it may be acquired from the outside if necessary.

In the third embodiment, the "read request" is sent so that the frame data is received immediately before the frame data is needed. However, the present invention is not limited to this, and a buffer for temporarily storing the frame data is provided. It may be configured such that a capacity is provided so that one or more frames are received in advance. In that case, it is possible to prevent the data from being discarded due to the fluctuation of the delay.

In the third embodiment, the predetermined factor is determined by the number of read requests accumulated in the moving image storage section. However, the present invention is not limited to this, and the delay time such as the load required to read the frame data may be determined. Other factors involved may also be relevant. Or you may make it judge including these.

[0054]

As is apparent from the above description, according to the present invention, the data to be read can be read by the time required for reproduction, and the data to be read can be read out without increasing the buffer capacity for temporarily storing the read data. It has an advantage that the fluctuation of the receiving interval can be suppressed and the transmission fluctuation can be suppressed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a real-time data reading system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of a moving image data read control unit according to the first embodiment.

FIG. 3 is a diagram showing an example of sequence data stored in a sequence data storage unit in the first embodiment.

FIG. 4 is a diagram showing an example of a control sequence of a moving image data read control unit and a moving image storage unit according to the first embodiment.

FIG. 5 is a diagram showing an example of delay information managed by a delay management unit according to the second exemplary embodiment of the present invention.

FIG. 6 is a diagram showing an example of a control sequence of a moving image data read control unit and a moving image storage unit according to the second embodiment.

FIG. 7 is a block diagram showing an internal configuration of a moving image data read control unit according to a third embodiment of the present invention.

FIG. 8 is a block diagram showing an internal configuration of a moving image storage unit in the third embodiment.

FIG. 9 is a diagram showing an example of a control sequence of a moving image data read control unit and a moving image storage unit according to the third embodiment.

[Explanation of symbols]

 1a, 1b, 1c Moving image storage unit 2a, 2b Moving image data read control unit 3 Data transmission path 4 Sequence data storage unit 5 Read request transmission unit 6 Delay management unit 8 Sequence data storage unit 9 Read request transmission unit 10 Delay information reception management unit 12 Video Management Section 13 Read Request Reception Section 14 Delay Information Transmission Section

Claims (6)

[Claims] 1. One or a plurality of data accumulating units for accumulating data such as moving images and audio by dividing into units, and a data reading request to the data accumulating unit, and the read data is specified. In the real-time data read system including one or a plurality of data read control units that output at the timing of, the data read control unit includes a read request sending unit that issues a data read request to the data storage unit. , Data receiving means for receiving the data read by the read request,
A delay management unit that measures and manages a delay time from when the read request is issued to when the data is received; and the read request sending unit, the scheduled time at which the received data should be output at the predetermined timing, and the delay time. A real-time data reading system, wherein a read request is made based on the delay time managed by the delay management means. 2. The real-time data read system according to claim 1, wherein the read request sending means makes a read request based on the scheduled time and at least the delay time measured immediately before. 3. One or a plurality of data accumulating units for dividing and accumulating data such as moving images and audio in units, and a data read request to the data accumulating units, and the read data is specified. In the real-time data reading system including one or a plurality of data reading control units for outputting at the timing of
A delay information transmission unit that estimates a delay time that occurs based on a predetermined delay factor and transmits delay information of the estimated delay time to the data read control unit, wherein the data read control unit is configured to store the data Read request sending means for making a data read request to the unit, data receiving means for receiving the data read by the read request, and delay information transmitted from the delay information transmitting section, and reception thereof And a delay information reception management unit for setting a delay time of the delay information, wherein the read request transmission unit is set in the delay information reception management unit and the scheduled time at which the reception data should be output at the predetermined timing. A real-time data read system characterized by making a read request based on a delay time. 4. The real-time data reading system according to claim 1, wherein the setting of the delay time is performed for each of the data storage units. 5. The delay information transmission unit of the data storage unit,
The real-time data read system according to claim 3, wherein the delay information is transmitted to the data read control unit only when the estimated delay time varies. 6. The real-time data read system according to claim 3, wherein the predetermined delay factor is the number of read requests existing in the data storage unit.