JP2001359074A - Variable quality multimedia data streaming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method that can reproduce a moving picture/a voice in real time independently of the propriety of a state of a network (congestion and deterioration in data quality). SOLUTION: The method of this invention includes a storage step where a server stores basic data to obtain reproduction data with basic quality and difference data being a difference between data to obtain reproduction data with higher quality than the basic quality and the basic data, a transmission step where a server transmits the basic data and the difference data to a client according to a request from the client, and a reproduction step where the client uses the basic data and the difference data to reproduce the reproduction data when the transmission of the difference data is finished at the end of the transmission of the basic data or the client uses only the basic data to reproduce the reproduction data when the transmission of the difference data is not finished at the end of the transmission of the basic data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for controlling file transfer on a network using a computer,
In particular, the present invention relates to a method for receiving and reproducing (streaming) multimedia data in real time on the Internet / intranet.

[0002]

2. Description of the Related Art As an example of streaming of well-known moving image / audio data (multimedia data), a user specifies moving image / audio data linked from a web page by a web browser, There is a mode in which the stored (cached) data is sequentially played back while being downloaded by the playback client software. As shown in FIG. 4, this conventional system includes a server 1-1 that is a computer that holds data, and a client 1 that is a side that receives data.
-4, transmission / reception software 1-6 for controlling data transmission / reception therein, reproduction software 1-5 for reproducing received data, server 1-1 and client 1
-4 network (such as the Internet)
1-7, management data 1-2 placed in the server, and actual data 1-3.

[0003] The conventional multimedia data streaming system having such a configuration operates as follows.

[0004] That is, the client 1
-4, the transmission / reception software 1-6 transmits the data to the server 1 via the network 1-7.
Request data for -1.

Although it depends on the data format, the management data 1-
2 and the actual data 1-3, the transmission / reception software 1-6 first receives the management data 1-2 and then requests reception of the actual data 1-3. . The transmission / reception software 1-6 passes the data being received to the reproduction software 1-5 every time it accumulates to some extent, and the reproduction software 1-5 reproduces the data.

[0006]

The first problem is that sometimes it takes a long time before data is reproduced on the client side.

The reason is that the state of the network (congestion,
This is because the size of the data placed on the server side cannot be changed regardless of the quality of the (line quality degradation), and it is extremely difficult to know the state of the network with the client from the server side.

Further, depending on the user's usage environment, it may be necessary to receive high-quality moving image / audio data over a low-speed line. In many cases, the moving image / audio data whose file size is large will be reproduced. As
It is considered that real-time reproduction cannot be performed and the reproduction tends to be interrupted.

A second problem is that the conventional method cannot cope with an unexpected change in the state of the network.

[0010] The reason is that, even in the conventional system, before requesting data reception / reproduction, it is possible for the user to judge whether to perform reception / reproduction by comparing his environment with the data size and the like. This is because there is a possibility that data reception may be delayed due to network congestion after reception has been started, and it is not possible to know this in advance.

An object of the present invention is to provide a method capable of real-time reproduction of moving images and sounds irrespective of the quality of network conditions (congestion, data quality deterioration).

Another object of the present invention is to realize data reproduction with a quality adapted to the environment of the user (client) without installing special hardware on the server.

[0013]

SUMMARY OF THE INVENTION A variable quality multimedia data streaming method according to the present invention comprises: basic data for obtaining reproduction data of a quality which is the basis of the variable quality multimedia data streaming method; An accumulation step of accumulating difference data, which is a difference between data for obtaining high-quality reproduction data and the basic data, in a server, and, in accordance with a request from a client, transmitting the basic data and the difference data from the server to the client. The transmitting step of transmitting, and if the transmission of the differential data is also completed at the time when the transmission of the basic data is completed, the client reproduces the reproduced data using the basic data and the differential data, and The transmission of the difference data must be completed at the time when the data transmission is completed. If, characterized by having a a playback step of playing back the playback data by using only the basic data at the client.

In the variable quality multimedia data streaming method according to the present invention, in the variable quality multimedia data streaming method described above, the difference data is provided in a plurality of steps.

Further, in the variable quality multimedia data streaming method according to the present invention, in the above variable quality multimedia data streaming method, the basic data and the difference data are divided, and the storage step and the transmission are performed in divided units. And performing the reproducing step.

Further, in the variable quality multimedia data streaming method according to the present invention, in the variable quality multimedia data streaming method, when the transmission of the difference data is not completed in the transmission step for a certain division unit, the next division is performed. It is characterized in that the difference data transmitted in the transmission step for the unit is reduced.

Further, in the variable quality multimedia data streaming method according to the present invention, in the variable quality multimedia data streaming method, when the transmission of the difference data is completed in the transmission step for a certain division unit, the next division is performed. It is characterized in that difference data to be transmitted is increased in a transmission step for a unit.

A computer-readable recording medium according to the present invention comprises a computer for storing basic data for obtaining reproduction data of a basic quality, data for obtaining reproduction data of a higher quality than the basic quality, and A receiving unit that receives the basic data and the differential data in response to a request from a server that stores the differential data that is a difference from the basic data, and that the transmission of the differential data is terminated when the transmission of the basic data is completed. If the client reproduces the reproduction data by using the basic data and the difference data, and if the transmission of the difference data is not completed at the time when the transmission of the basic data is completed, the client performs the reproduction of the basic data. A reproduction means for reproducing reproduction data using only data, and a program for functioning as reproduction means recorded And it features.

Further, a computer-readable recording medium according to the present invention is characterized in that in the above-mentioned computer-readable recording medium, a plurality of the difference data are provided in a stepwise manner.

Further, in the computer readable recording medium according to the present invention, in the above computer readable recording medium, the basic data and the difference data are divided, and the receiving means and the reproducing means are divided. It operates on a unit basis.

Further, in the computer-readable recording medium according to the present invention, in the above-mentioned computer-readable recording medium, when the transmission of the difference data is not completed in the transmission for a certain division unit, the receiving means is provided with the following: It is characterized in that difference data transmitted for each division unit is reduced.

Further, in the computer-readable recording medium according to the present invention, in the above-mentioned computer-readable recording medium, when the transmission of the differential data has been completed in a certain division unit, the receiving means may execute the next division. It is characterized in that the difference data to be transmitted per unit is increased.

As shown in FIG. 1, the system according to the present invention includes management data 2-2 on the server 2-1 side and data 2-3-1, 2-3-2,. 2-3
-N, and the client 2-4 side includes transmission / reception software 2-6 as data transmission / reception control means and synthesis software 2-5 as synthesis means, and is controlled by the transmission / reception software 2-6. It operates to select and receive appropriate data on the server side.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] Next, a first embodiment of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 2, a first embodiment of the variable quality multimedia data streaming system according to the present invention is a server 3 which is a computer (central processing unit; processor; data processing unit) operated by program control. 9, a client 3-10, and transmission / reception software 3- therein for controlling transmission / reception of data.
13. Synthesis software 3-1 for synthesizing received data
2. Reproduction hardware 3-11 for reproducing data;
The network includes a network 3-15 connecting the client 3-10 and the server 3-9, a server program 3-16, and a user 3-14 operating the client 3-10.

In the present embodiment, moving image data is handled and its recording quality is set to three levels. In this case, however, management data 3- having configuration information 3-1, 3-2, and 3-3 as elements. 7. Similarly, real image data 3-8 having basic contents 3-4 and difference contents 3-5 and 3-6 as elements are stored in the server 3-9.

The actual image data 3-8 in the server 3-9 is
Basic contents (basic data) 3-4 when data is divided into three as basic data, medium-resolution data, and high-resolution data for each recording quality band (resolution), and a difference between medium-resolution data and basic contents 3-4. 3-5, which is configured as a set of differences 3-6 between high-resolution data and medium-resolution data, and how many original data are divided by the management data 3-7 and stored under what file names Manage and so on.

Each of these means operates as follows.

The transmission / reception software 3-13 receives the management data 3-7, and receives basic contents 3-4 and difference contents 3-5 and 3-6 as constituent elements based on the contents.

The synthesizing software 3-12 receives the data from the transmission / reception software 3-13, synthesizes them, and passes them to the reproducing hardware 3-11.

The reproduction hardware 3-11 reproduces the received data.

Next, the overall operation of this embodiment will be described in detail with reference to FIG.

First, the user 3-14 instructs the transmission / reception software 3-13 through the synthesis software 3-12 to receive image data. Next, the transmission / reception software 3-13 receives the management data 3-7 for the image to be sought in the server 3-9.

The transmission / reception software 3-13 analyzes the content of the received management data 3-7, and knows what kind of file name each of the image data to be sought is composed of three elements.

Further, transmission / reception software 3-13
Is based on the analysis result of the management data 3-7.
Start receiving data. At the same time, it requests reception of the difference contents 3-5 and 3-6.

When the transmission / reception software 3-13 completes the reception of the basic content 3-4, the transmission / reception software 3-13 outputs 3-4 and 3-5 if the reception of the difference content 3-5 is completed, and the difference content 3-6. If the reception is completed, 3-4, 3-5, and 3-6 are passed to the synthesizing software 3-12. For data for which reception has not been completed, reception is canceled.

The synthesizing software 3-12 synthesizes only the received data and passes it to the reproducing hardware 3-11. The reproduction hardware 3-11 reproduces the result, and the user 3-14 obtains the desired result.

In this embodiment, the smaller basic data and the larger difference data are transmitted in parallel. Since the data size is different, smaller data can be expected to reach the client first. Playing a moving image requires a certain amount of time (recording time) regardless of the amount of data, so differential data of a moderately small size is set according to the lowest speed among commonly used communication speeds. In the other communication at a higher general speed, reception of not only basic data but also differential data can be expected.

Next, effects of the present embodiment will be described.

In the present embodiment, a general H
Since special software and hardware other than the TTP server program and the FTP server program are not required, a system can be constructed inexpensively and easily.

Also, no special hardware is required on the client side, and the user can extract desired data with an image quality corresponding to the line speed used by the user.

[Second Embodiment] Next, a second embodiment of the present invention will be described.
An embodiment will be described in detail with reference to the drawings.

Referring to FIG. 3, according to a second embodiment of the present invention, a server 4-2 which is a computer (central processing unit; processor; data processing unit) operated under program control; Transmission / reception software 4 for controlling data transmission / reception therein
-7, synthesis software for synthesizing received data 4-
6. Reproduction hardware 4-5 for reproducing data, a network 4 connecting the client 4-8 and the server 4-2.
-3, a server program 4-9, and a user 4-4 operating a client 4-8.

The data provided by the server 4-2 is divided into N parts in advance in the time direction with an appropriate length (partial management data 4-1-1 to 4-1-N, basic / difference contents). 4-1-1 ′ to 4-1-N ′).

Information such as the temporal order and the file name is managed by the overall management data 4-10.

The divided individual data includes partial management data 4-1-1 as management information and partial contents 4-1-1 'as actual data, and furthermore, partial management data 4-1-2 and partial data 4-1-2. It is composed of a set of management information and actual data, such as content 4-1-2 ′.

If the content is audio, the partial content 4-1-1 'is considered in the Y-stage frequency band, and
Difference contents 4-1-12 'and 4-1-1 in -1-11'
3 ′,..., 4-1-1Y ′ are sequentially combined to divide and compose the speech data in a stepwise manner so that high-quality audio data is obtained.
.., 4-1-1Y are stored in the partial management data 4-1-1. The same applies to the partial contents 4-1-2 ′ and thereafter.

If the content is a moving image, the resolution or image quality in the Y stage is considered, and each difference content is similarly synthesized with the basic content as a base, so that the video data is divided stepwise into higher-quality moving image data. ·Constitute.

Each of these means operates roughly as follows.

The transmission / reception software 4-7 receives the overall management data 4-10 and determines the reception order of each partial data based on the contents.

Further, in accordance with the determined receiving order, first, the partial management data 4-1-1 is received, and its contents 4-1-1-1.
Basic contents 4-1-1 based on 11-4-1-1Y
1 ′ and the difference contents 4-1-12 ′ to 4-1-1Y ′ are received. Subsequently, the partial management data 4-1-2 and the partial contents 4-1-2 ', 4-1-3 and 4-1-3',...
And 4-1-N and 4-1-N 'are similarly received.

The synthesizing software 4-6 receives data from the transmitting / receiving software 4-7 as needed, synthesizes the data, and transfers the synthesized data to the reproducing hardware 4-5.

The reproduction hardware 4-5 reproduces the received data.

Next, the overall operation of this embodiment will be described in detail with reference to FIG.

First, the user 4-4 issues a data reception request in the server 4-2 to the transmission / reception software 4-7 through the synthesis software 4-6.

The transmission / reception software 4-7 first receives the overall management data 4-10, and knows the order in which the data placed in the server 4-2 and divided into N should be received.

In accordance with the order, the partial management data 4
-1-1 is received. Further, according to the information therein, the basic contents 4-1-11 'and the difference contents 4-1-12' to 4-1
-1Y 'is received.

Further, in accordance with the information of the overall management data 4-10, a request for receiving the partial management data 4-1-2 is made in parallel.

If there is any difference contents 4-1-12 'to 4-1-1Y' at the time when the basic contents 4-1-11 'have been received, the basic contents 4-1-11' And pass it to the synthesis software 4-6. Cancel the reception during the reception.

If the partial management data 4-1-2 has been received, the basic contents 4-1-21 'and the difference contents 4
−1-22 ′ to 4-1-2Y ′ are requested to be received,
If there is a difference content that could not be received in the reception situation of the immediately preceding content 4-1-1 ', the difference content 4-1-22'
４−4-1-2Y 'is not requested, but only a part of the request.

Further, in accordance with the information of the overall management data 4-10, a request for receiving the partial management data 4-1-3 is made in parallel.

The synthesizing software 4-6 synthesizes the passed basic contents + difference contents to restore a partial moving image corresponding to the partial contents 4-1-1 '.

The reproduction hardware 4-5 reproduces a moving image.

As before, the basic contents 4-1-21 '
When the reception is completed, the difference contents 4-1-22 'to 4-1
If there is any that has been received at -2Y ', basic contents 4
It is passed to the software for synthesis 4-6 together with -1-21 '. Cancel the reception during the reception.

If the partial management data 4-1-3 has been received, the basic contents 4-1-31 'and the difference contents 4
Requests for receiving -1-32 'to 4-1-3Y' are made in advance. However, similarly to the previous case, if there is a difference content that has not been received in the reception status of the immediately preceding content 4-1-2 ′, all the difference contents (4-1-22 ′ to 4-1-2) requested last time are received.
(Part of Y ′) Not requesting all, but requesting only a part. In the case where all the contents have been received in the reception situation of the immediately preceding content 4-1-2 ′, the difference content requested to be received is increased from the previous time.

Thereafter, the user obtains a desired reproduction result by repeating N times in the same manner and reproducing each portion.

Next, the effect of the present embodiment will be described.

In this embodiment, since the data on the server side to be reproduced is divided in the time length direction,
The result of each divided unit can be reflected in the number of reception requests of the next part, and as a result, the amount of received data can be dynamically changed.

[0069]

The first effect is that the real-time property at the time of streaming reproduction of moving image and audio data on the server side is not impaired by the line speed and quality between the server and the client.

The reason is that the amount of data to be downloaded is changed according to the line speed between the server and the client.

The second effect is that data can be reproduced flexibly in response to changes in the line speed and quality without deteriorating the real-time property.

The reason is that if the supplementary part (the above-mentioned difference content) of the data to be downloaded cannot be downloaded, it is used as a basis for network congestion or the like. This is because it can be reflected in the next download request number as a basis for the fact that the line has room.

A third effect is that the above-described effects can be obtained by using the web server and the client configuration, which have been widely used conventionally, almost as they are.

The reason is that the installation of the dedicated software is necessary only on the client side, and the server side only needs to care about the data structure. This is because it can be said that this is an operation mode of a web server.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of a variable quality multimedia data streaming system according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a variable quality multimedia data streaming method according to a first embodiment of the present invention.

FIG. 3 is a block diagram illustrating a variable quality multimedia data streaming method according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a multimedia data streaming system according to a conventional example.

[Explanation of symbols]

1-1, 2-1, 3-9, 4-2 Server computer 1-4, 2-4, 3-10, 4-8 Client computer 1-7, 2-7, 3-15, 4-3 Network (Network; computer network; Internet) 2-6, 3-13, 4-7 Transmission / reception software 2-5, 3-12, 4-6 Synthesis software 1-2, 2-2, 3-7, 4- 1-n management data (management information) 2-3-n, 3-4, 3-5, 3-6, 4-1-ny '
Content (content data)

Claims (10)

[Claims] 1. A server for transmitting basic data for obtaining reproduction data of a basic quality, and difference data, which is a difference between data for obtaining reproduction data of higher quality than the basic quality and the basic data, to a server. An accumulating step of accumulating; a transmitting step of transmitting the basic data and the differential data from the server to the client in accordance with a request from the client; and a transmission of the differential data is terminated when the transmission of the basic data is completed. If, the client reproduces the reproduction data using the basic data and the differential data, and if the transmission of the differential data is not completed at the time when the transmission of the basic data is completed, the client performs the A reproduction step of reproducing the reproduction data using only the basic data; and Media data streaming method. 2. The variable quality multimedia data streaming method according to claim 1, wherein the difference data is provided in a plurality of steps in a stepwise manner. 3. The variable quality multimedia data streaming method according to claim 1, wherein the basic data and the differential data are divided, and the storing step, the transmitting step, and the reproducing step are performed in divided units. A method for streaming variable quality multimedia data, comprising: 4. The variable quality multimedia data streaming method according to claim 3, wherein when the transmission of the differential data is not completed in the transmission step for a certain division unit, the transmission is performed in the transmission step for the next division unit. A variable quality multimedia data streaming method characterized by reducing differential data. 5. The variable quality multimedia data streaming method according to claim 3, wherein when the transmission of the differential data has been completed in the transmission step for a certain division unit, the transmission step for the next division unit is performed. A variable quality multimedia data streaming method characterized by increasing differential data to be transmitted. 6. A computer, comprising: basic data for obtaining reproduction data of a basic quality; difference data for obtaining reproduction data of higher quality than the basic quality; Receiving means for receiving the basic data and the differential data in response to a request from a server storing the basic data, if the transmission of the differential data has also been completed at the time when the transmission of the basic data has been completed, Reproduction data is reproduced using the data and the difference data, and if the transmission of the difference data is not completed at the time when the transmission of the basic data is completed, the reproduction data is reproduced by the client using only the basic data. A computer-readable recording medium, on which a program for causing the reproducing means to function as a computer is recorded. 7. The computer-readable recording medium according to claim 6, wherein the difference data includes a plurality of difference data in a stepwise manner. 8. The computer-readable recording medium according to claim 6, wherein the basic data and the difference data are divided, and the receiving unit and the reproducing unit operate in divided units. A computer-readable recording medium characterized by the above-mentioned. 9. The computer-readable recording medium according to claim 8, wherein when the transmission of the difference data is not completed in the transmission of a certain division unit, the receiving unit transmits the difference data of the next division unit. A computer-readable recording medium characterized by reducing the amount of data. 10. The computer-readable recording medium according to claim 8, wherein when the transmission of the differential data has been completed for a certain division unit, the receiving unit transmits the difference data for the next division unit. A computer-readable recording medium characterized by increasing data.