JPH09186967A - Moving image processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quicken a response at data changeover in the video-on-demand system. SOLUTION: In the case of the special reproduction mode, a server transfers special reproduction data and usual reproduction data to be reproduced next in a special reproduction transfer format 202. In the case of conducting the special reproduction, only the special reproduction data are extracted and reproduced and usual reproduction data following next are aborted. In the case of occurrence of a reproduction changeover request from the user, a client transfers a changeover request of changeover from the special reproduction to usual reproduction to the server. The server receiving the request transfers usual reproduction data to be reproduced next and remaining usual reproduction data having been transferred before. When the client confirms the data transfer of a usual reproduction data transfer format 201, the client extracts the usual reproduction data from th format 202 and reproduces the data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture processing method for transmitting and receiving moving picture data to perform fast forward reproduction, rewind reproduction, normal reproduction and the like.

[0002]

2. Description of the Related Art In recent years, MPEG1 (Movin
g Picture Experts Group: Reference MPEG Commitiee D
Raft System Video, Audio) encoded data is transferred over the network for video conferencing, home shopping,
Systems for video-on-demand are being developed. In systems such as video-on-demand, there is a demand for playing back at a higher speed than usual to browse the screen, in addition to playing at a normal speed. In order to deal with this, it is necessary to transfer the compressed data at a higher speed than usual on the server side and to reproduce at high speed on the client side. However, if a server that transfers moving image data to a plurality of clients performs high-speed data transfer during special playback such as rewind playback or fast forward playback, the number of clients that can be supported decreases. Also, since it is necessary for the client side to decode and reproduce at high speed, if the processing capacity is low, high speed reproduction is impossible.

As a method for solving the above-mentioned problems, there is a method in which special reproduction data is prepared in advance in addition to the normal reproduction data, and the server side changes the transfer data according to a request. At this time, data for special reproduction is generated by thinning out pictures from normal reproduction data. Therefore, the data transfer size during trick play is smaller than the data transfer size during normal play, and it is possible to support trick play without changing the number of clients that can be supported. There is no need for the client to perform high speed decoding.

[0004]

In the above-mentioned prior art, since the data for normal reproduction and the data for special reproduction are separately prepared in advance and the transfer data is switched at the request of the client, the server which receives the switching request receives the data. However, since new data has not arrived on the client side until the transfer, the reproduction cannot be performed and smooth switching cannot be performed.

The present invention has been made in view of the above circumstances. An object of the present invention is to solve the above-mentioned problems in the prior art and to perform normal reproduction and browsing in a system such as video-on-demand. It is to provide a moving image transfer method for smoothly switching special reproduction for.

[0006]

The object of the present invention is to transfer the request for switching from special reproduction to normal reproduction to the server at the same time as the reception of the normal reproduction data is confirmed at the same time as the reception of the special reproduction data. This is achieved by displaying the normal reproduction data added to the rear.

In the moving image processing method according to the present invention, the client transfers the switching request to the server and displays the added moving image data until a response is obtained, thereby enabling smooth display switching.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a storage system and a management system of normal reproduction data and special reproduction data according to an embodiment of the present invention. The data 102 is normal reproduction data compressed by the MPEG standard, and is managed by the data management table 101.
By referring to the address 105 of the normal reproduction data, random access can be performed in GOP (Group Of Picture) units. In this embodiment, the picture rate is 30 [f / s],
The number of pictures in GOP is 30. In other words, 1 GOP is 1
Second picture data.

The normal reproduction data 101 includes I, P, B
The pictures are included in the array as shown in FIG. 1, and one I picture, which is data that is not differentially compressed, is included in each GOP.
There is one. The data 103 is special reproduction data generated by extracting an I picture from normal reproduction data compressed by the MPEG standard, and has an address 1 of special reproduction data.
By referring to No. 06, the data is managed by the data management table 101 like the normal reproduction data, and random access is possible in GOP units. Index 104 is 0 to n
Up to n, depending on the length of the video data.

The data size in 1 GOP of this embodiment is 200 KB for normal reproduction data and 20 KB for special reproduction data. When performing normal playback, the client plays 200 KB, which is 1 GOP of normal playback data per second. Since the special reproduction data is the data obtained by extracting one from 30 pictures, the speed depends on the number of pictures to be reproduced, such as 1 time for reproduction of 1 picture per second, 2 times for 2 pictures ... Can be variable. In other words, when performing double special playback, 2 GO of special playback data per second
You only have to play 40 KB, which is P minutes.

FIG. 2 shows a transfer format of moving image data in this embodiment. Usually formats 201 and 2
The data size of 02 is the same. Here, the size of the normal playback data 1GOP is 200KB and the header size is 3KB.
It will be 03KB. The format 201 transfers the data 102, which is normal reproduction data, in GOP units. Header 2
03 includes a data type (205) and normal reproduction data 21.
3 size (206) and special playback data size (2
07) is stored. The format 202 is a data transfer format at the time of special reproduction data transfer, and the normal reproduction data 212 is added after the special reproduction data 211.

In the header 204, the data type (20
8), special reproduction data size (209) and normal reproduction data size (210) are stored. When double speed special reproduction data is transferred using the data 103, the format 202 is 2 GOPs of the special reproduction data 103.
It is composed of 40 KB and the head 160 KB of the normal reproduction data 102. Here, the normal reproduction data (211) stores data to be reproduced next to the special reproduction data (212). That is, the special reproduction data of the index GOP0 is followed by the normal reproduction data of the index GOP1 to form the format 202.

FIG. 3 shows a video according to an embodiment of the present invention.
The hardware configuration for building an on-demand system is shown.

In FIG. 3, reference numerals 301 to 303 denote servers 300 for transferring moving image data. Reference numeral 301 denotes a processor for controlling each device, which operates according to a program and a management table stored in the program memory 302. Reference numeral 303 denotes a secondary storage device for storing moving image data, and a hard disk is used in this embodiment. The hard disk 303 stores the normal reproduction data, special reproduction data, and data management table shown in FIG.

The moving image data is managed by the index counter, speed and data management table in the program memory 302, and the data to be transferred next is the memory 30.
It is read into the buffer in 2. Then, it is transferred to the client 1 (306) via the network 304. The client 1 receives the transferred data in the buffer in the memory (308). The processor 307 of the client 1 refers to the mode indicating the display state of the client in the memory (308), passes the moving image data to the decoder 308, and displays it on the display 310.
Like the client 1, the clients 2 (311) to N (312) use the network 304 to connect to the server 30.
It is tied to 0 and receives video data. The server transfers the moving image data to the clients 1 to N in the format of 201 or 202 at a cycle of 1 second.

4 and 5 are time charts showing the outline of the data transfer procedure between the server and the client in the embodiment of the present invention.

FIG. 4 is a diagram showing a switching process from the normal reproduction start to the special reproduction. In process 401, the client receiving the display request from the user is processed by process 402.
Transfer the normal playback start request to the server. In step 403, the server having received the request sequentially transfers the normal reproduction data in units of 1 GOP from the data corresponding to the index GOP0 of the normal reproduction data (101).

The client receives the data from the server in the buffer 1 in process 404, waits for the next data reception (process 405) for 1 second, and reproduces 1 GOP worth of data. Next, in process 404, the data received in the buffer 2 is reproduced. The processing of 404 and 405 is repeated to reproduce the moving image.

In step 407, the client receives the trick play request from the user in step 406 and transfers the playback data switching request to the server in step 407. The server receives the request, and transfers the trick play data in process 408. The client receives trick play data and starts trick play.

Next, FIG. 5 shows the switching process from special reproduction to normal reproduction.

In process 501, the client which receives the normal reproduction request from the user transfers the reproduction data switching request to the server in process 502. The server receives the request, and in process 503, switches to reading normal reproduction data. The data read here is the remaining data of the normal reproduction data read in the process 507 and the data for the next 1 GOP. At the interval 508 from when the request is sent to the server to when the normal reproduction data arrives, special reproduction is performed. When the normal reproduction data arrives in the process 504, the client transfers the format 2 which has been transferred and is stored in the buffer in the process 505.
From the data No. 02, the special reproduction data is discarded and only the normal reproduction data is taken out and the normal reproduction is performed. When the decoding process is completed, the remaining normal reproduction data is retrieved from the buffer 2 and reproduced in process 506. After that, normal playback is continued.

Next, a detailed description will be given of the data storage method shown in FIG. 1 in the server / client system shown in the system of FIG. 3 according to the time charts of FIGS. 6 and 7
This will be described with reference to FIG.

FIG. 6 is a flow chart showing the processing procedure of the server in the embodiment of the present invention.

At step 601, a request from the client is received, and if the request is a reproduction start or switching request, at step 603 an index counter and speed in memory are set.
When the reproduction is started, the index counter is set to 0 and the speed is set to 1. In the case of a switching request, the index counter is left unchanged and the speed is set to the value (1 or more) specified by the request. In step 604, the data management table 201 is referred to by the values of these counters, and the normal reproduction data is read into the buffer in the memory 303. After the data in the buffer is transferred in step 607, the index counter is updated in step 608. In step 609, it is compared whether the index counter is greater than or equal to the end value (N), and if not, the above processing is continued until the data switching request or the end request is issued from the client.

Next, the processing when a request for switching from the normal reproduction data to the special data is generated will be described. After the server transfers the data of the index GOP (I), if a data switching request occurs, the speed value is updated in step 603. Next, step 604.
At, the special reproduction data of GOP (I + 1) is read. In steps 605 and 607, normal reproduction data of GOP (I + 2) is added after the special reproduction data as shown in the format 202. Here, the size of the normal reproduction data to be added is determined by the following formula.

Normal data size per 1 GOP-1 GOP
Special playback size per hit x Special playback speed where 1G
If the normal data size per OP is 200KB, the special playback size per 1GOP is 20KB, and the special playback speed is 2, 160KB of normal playback data will be added after the special playback data and transferred. That is, 204 in FIG.
Special data size is 40KB, normal data size is 16
It will be 0 KB. Next, in step 607, the data is transferred to the client. After transfer, steps 608, 60
In step 9, the index counter is updated, and the above processing is continued until the data ends or the data switching request and the end request are issued from the client.

When a switching request is received during the transfer of special reproduction data, the following processing is performed. Step 60
In 3 and 604, the management table of the data to be transferred next is referred to. When it is determined in steps 605 and 610 that the processing immediately after switching from special reproduction to normal reproduction is to be performed, the index counter is updated in step 611. Then, in step 612, the remaining data of the data added and transferred after the special reproduction data is read and the counter is updated. In step 613, the next data is read and transferred.

FIG. 7 is a flow chart showing the processing procedure of the client in the embodiment of the present invention.

At the client, steps 701-70
When the input from the user in 4 is the start of normal reproduction, the request is transferred to the server. As a result, the server performs the above-mentioned processing and transfers the normal reproduction data. Then, in step 705, the mode in the memory 308 is set to normal reproduction. In step 706, data transfer from the server is awaited. When the data arrives, the data is transferred to the decoder 309 by 709. The processes of 706 and 709 are repeated until the next user input is made.

When the user's input is switching from special reproduction to normal reproduction, the following processing is performed. The client
In step 703, it is determined that the request is a switching request, and the request is transferred to the server. Next, the mode is changed to normal playback. When the normal reproduction data arrives from the server in steps 707 and 709, the format 202 data is discarded in the buffer, and the first special reproduction data is discarded to decode the normal reproduction data. When the decoding of the data is completed, the transferred data is reproduced. As a result, it becomes possible to quickly switch to the normal reproduction data in response to the user input.

[0032]

As described above, according to the present invention,
The operation of switching the moving image data by the input from the user can be started without waiting for the arrival of the data from the server. As a result, it is possible to shorten the response time and switch data, and instantly switch between normal playback and special playback, which is useful for improving the user interface.

[Brief description of the drawings]

FIG. 1 is an example of a moving image data structure and a data management table according to an embodiment.

FIG. 2 is an example of a transfer data format according to an embodiment of the present invention.

FIG. 3 is a hardware configuration diagram according to an embodiment of the present invention.

FIG. 4 is a time chart of a switching process from normal reproduction start to special reproduction.

FIG. 5 is a time chart of a switching process from special reproduction to normal reproduction.

FIG. 6 is a flowchart of a processing procedure of a server.

FIG. 7 is a flowchart of a processing procedure of a client.

[Explanation of symbols]

 201 ... Normal reproduction data transfer format, 202 ... Special reproduction data transfer format, 203 ... Normal reproduction data transfer format header, 204 ... Special reproduction data transfer format header

Claims (4)

[Claims] 1. A moving image processing method using a moving image transmitting apparatus that collectively manages moving image data and a moving image receiving apparatus that receives and reproduces moving image data transferred from the moving image transmitting apparatus. A moving image processing method in which normal reproduction data and trick reproduction data are simultaneously transferred as moving image data to be transferred from the device, and the moving image transmission device selects the data to reproduce the moving image. 2. The moving image processing method according to claim 1, wherein when the moving image receiving device executes special reproduction, the moving image transmitting device transfers the special reproduction data and normal reproduction data to the moving image receiving device, A moving image processing method in which when the receiving device executes normal reproduction, the moving image transmission device transfers only normal reproduction data to the moving image reception device. 3. The moving image processing method according to claim 1, wherein when performing special reproduction, only special reproduction data is reproduced from the special reproduction data and the normal reproduction data transferred from the moving picture transmission device, and the reproduction data is switched. A moving image processing method in which when the processing is transferred to the moving image transmitting apparatus, the moving image transmitting apparatus confirms that the normal reproducing data has been transmitted, and at the same time, reproduces only the normal reproducing data from the special reproduction data and the normal reproducing data which have been transferred. 4. The moving picture processing system according to claim 2, wherein the normal reproduction data and the special reproduction data are managed at a constant interval for transferring the moving picture, and the special reproduction data and the next reproduction are reproduced when the special reproduction data is transferred. A moving image processing method characterized by managing a storage location from which normal reproduction data to be read is read.