JP2001184798A - Moving picture reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moving picture reproducing device suitable for preventing generation of a flicker in a moving picture to be reproduced when the moving picture is reproduced by decoding and displaying image data to be included in moving picture data in an OS to be operated by multi-task. SOLUTION: This moving picture reproducing device is provided with buffers B1, B2 to store image data to be decoded based on B data separately from buffers A, C and the moving image is reproduced as executing a decode processing to input the moving picture data including I data, P data and plural pieces of the B data in this order, to decode the image data to the buffers A, C based on the I data, to decode the image data to the buffers C, A based on pieces of the I, P data and to successively decode pieces of the image data corresponding to each piece of the B data to the buffers B1, B2 based on pieces of the image data of the buffers A, C and each of the B data and a display processing to transfer pieces of the image data of each of the buffers A to C to a buffer for display and to display them in this order in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for reproducing moving images by decoding and displaying image data contained in moving image data. The present invention relates to a moving image reproducing apparatus suitable for preventing a reproduced moving image from flickering when the moving image is decoded and displayed.

[0002]

2. Description of the Related Art Conventionally, in an operation system (hereinafter simply referred to as an OS) that operates in a multitask mode, an MP
The decoding of the moving image data compressed in the EG format and the reproduction of the moving image are performed in the manner shown in FIG. FIG. 5 is a diagram for explaining a conventional moving image reproducing method.

[0003] Moving image data compressed in MPEG format is
I data, which can decode image data alone, P data, which is difference data between two image data, and two B data necessary for decoding image data that complements between the two image data, Include in order. Here, the P data is image data decoded based on the I data or P data that precedes that of the moving image data and is difference data between two consecutive image data. In order to decode the data, the image data is required in addition to the P data. The B data is image data decoded based on I data or P data that precedes that of the moving image data, and is a complement necessary for decoding image data that complements between two consecutive image data. In order to decode the image data based on the B data, the image data is required in addition to the B data.

Therefore, the moving picture data may be followed by two B data following the I data or the P data. In the example of FIG. 5, the moving picture data is composed of I ₀ data, P ₁ data, and B data.
₂ data, B ₃ data, P ₄ data, B ₅ data, B ₆ data, P ₇ data, B ₈ data, B ₉ data, I ₁₀ data,
B ₁₁ data, B ₁₂ data, P ₁₃ data, has become ... a, P ₁ data, P ₄ data, P ₇ data, after the I ₁₀ data is followed by two B data.

In the OS, a buffer A for storing image data decoded based on I data or P data, a buffer B for storing image data decoded based on B data, an I data or A buffer C for storing image data decoded based on the P data is secured in the RAM, and a display buffer for storing image data to be displayed is secured in the VRAM, A decoding process of inputting data and decoding image data included in moving image data, and a display process of transferring the decoded image data to a display buffer and displaying the image data stored in the display buffer are performed. The video is played back while being executed in parallel.

The decoding process is performed for a predetermined time T (for example, 2
0 [ms]), the process of decoding the image data at every 0 [ms]. Referring to FIG. 5 as an example, at time t ₀ , the I ₀ data of the moving image data is decoded into the buffer A, and at time t ₁ , the buffer A is decoded. P ′ _1, which is image data, based on the I ₀ data and the P ₁ data of the moving image data.
Decode the data into buffer C.

Next, at time t ₂ , image data B ′ ₂ data is decoded into buffer B based on I ₀ data of buffer A, P ′ ₁ data of buffer C and B ₂ data of moving image data, and At t ₃ , the image data B ′ ₃ data is decoded into the buffer B based on the I ₀ data of the buffer A, the P ′ ₁ data of the buffer C, and the B ₃ data of the moving image data.

Next, at time t ₄ , P ′ ₄ data as image data is decoded into buffer A based on P ′ ₁ data of buffer C and P ₄ data of moving image data.

Next, at time t_FiveIn the buffer A
P '_FourData, P 'of buffer C₁Data and video data
Ta no B_FiveB ′ which is image data based on the data_Fivedata
Is decoded into buffer B, and time t₆At the buff
A's P '_FourData, P 'of buffer C₁Data and dynamics
B of image data₆B ′ which is image data based on the data ₆
Decode the data into buffer B.

At time t ₇ , P ′ ₇ data as image data is decoded into buffer C based on P ′ ₄ data of buffer A and P ₇ data of moving image data. The following data is decoded in the same manner.

The display process is a process of transferring the image data in the buffers A to C to the display buffer every predetermined time T and displaying the image data stored in the display buffer. to illustrate, at time t _1, and to transfer and display I ₀ data in the buffer a in the display buffer, at time t _2, the display and transfer the B _'2 data in the buffer B in the display buffer, the time t in _3, and displays the transfer B _'3 data buffer B in the display buffer.

Next, at time t ₄ , the P ′ ₁ data of the buffer C is transferred to the display buffer for display, and at time t ₅ , the B ′ ₅ data of the buffer B is transferred to the display buffer for display. At time t ₆ , B ′ ₆ data in buffer B is transferred to the display buffer for display, and at time t ₇ , P ′ ₄ data in buffer A is transferred to the display buffer for display. The following data is transferred and displayed in the same manner.

[0013]

As described above, in the moving image reproducing method by the conventional OS, the moving image is reproduced while the decoding process and the display process are synchronized.

[0014] However, in the conventional moving image reproducing method by the OS, since the decoding process and the display process are executed in parallel, for example, the other process is executed by the OS. The decoding processing and the display processing may be out of synchronization due to an increase in processing load or the like.

That is, the buffer B is used to store two image data decoded based on the two B data, and the order in which the image data is transferred to the display buffer is determined as described above. since being, as shown in FIG. 5, for example, B 'immediately B at the next time t ₃ when decoding the buffer B ₂ data' to ₃ data must decode the buffer B. At this time, if the decoding process and the display process are out of synchronization,
Before the transfer of the B ′ ₂ data in the buffer B to the display buffer in the display processing, the B ′
By decoding the _third data into the buffer B, the state that the non-transferred portion of the B _'2 data in the buffer B will be rewritten could occur. When such a state occurs, the reproduced moving image flickers. This means that in FIG. 5, B _'5 data, B' ₈
The same is true for the data and B _'11 data.

Accordingly, the present invention has been made in view of such unresolved problems of the prior art, and decodes and displays image data included in moving image data in an OS operating in multitasking. It is an object of the present invention to provide a moving image reproducing apparatus suitable for preventing a reproduced moving image from flickering when reproducing a moving image.

[0017]

In order to achieve the above object, a moving picture reproducing apparatus according to the first aspect of the present invention comprises:
Of moving image data including compressed data, second compressed data, and a plurality of third compressed data in that order, and a first image based on the first compressed data of the input moving image data. Generating data, generating second image data based on the first compressed data and the second compressed data of the input moving image data, and generating the first compressed data of the input moving image data; Third image data corresponding to each of the third compressed data is sequentially generated based on the second compressed data and each of the third compressed data, and the generated first image data and each of the generated An apparatus for reproducing a moving image by displaying third image data and the generated second image data in that order, comprising: a first buffer for storing the first image data; Second Second for generating the image data
And at least two third buffers, and the third image data is generated using all of the third buffers.

With such a configuration, when moving image data is input, first image data is generated in the first buffer based on the first compressed data of the moving image data, and the first image data of the moving image data is generated. Second image data is generated in a second buffer based on the compressed data and the second compressed data, and the second image data is generated based on the first compressed data, the second compressed data, and each of the third compressed data of the moving image data. Third image data corresponding to each third compressed data is sequentially generated in these third buffers while all the third buffers are used. On the other hand, the first image data of the first buffer, the respective third image data of the third buffer, and the second image data of the second buffer are displayed in that order.

Therefore, in the third buffer, another third image data is generated immediately after the third image data is generated, as compared with the case where the third image data is generated using a single buffer.
Is less likely to be generated.

Here, the third buffer has at least two buffers.
The number of the third compressed data may be equal to the number of the third compressed data. However, the number of the third compressed data may be smaller than the third compressed data. From the viewpoint of being able to cope with the case where the synchronization with the data is greatly shifted, the number of the third compressed data may be larger. Hereinafter, the same applies to the moving image reproducing apparatus according to claims 2 and 3.

Further, the moving picture reproducing apparatus according to the second aspect of the present invention inputs moving picture data including first compressed data, second compressed data, and a plurality of third compressed data in that order. Then, first image data is generated based on the first compressed data of the input moving image data, and a second image data is generated based on the first compressed data and the second compressed data of the input moving image data. Generate image data of
A third image data corresponding to each of the third compressed data is sequentially generated based on the first compressed data, the second compressed data, and the third compressed data of the input moving image data. Decoding processing including generation, transferring the generated first image data, the generated third image data, and the generated second image data to the display buffer in that order, The display processing including the transfer and display for displaying the image data stored in the image buffer is performed in parallel with the first processing.
Image data, the respective third image data, and the second
For reproducing a moving image by displaying the first image data and the second image data in that order, and a second buffer for storing the first image data and a second buffer for generating the second image data. Aside from the buffer
Three third buffers, and the third image data is generated using all of the third buffers.

With this configuration, when moving image data is input, decoding processing generates first image data in the first buffer based on the first compressed data of the moving image data. The second image data is generated in the second buffer based on the first compressed data and the second compressed data of the first compressed data, the first compressed data, the second compressed data, and the third compressed data of the moving image data. The third image data corresponding to each of the third compressed data based on
While all the third buffers are used, they are sequentially generated in these third buffers. On the other hand, by the display processing, the first image data in the first buffer is transferred to the display buffer for display, and the third image data in the third buffer is transferred to the display buffer for display. The second image data in the second buffer is transferred to the display buffer and displayed.

Therefore, in the third buffer, another third image data is generated immediately after the third image data is generated, as compared with the case where the third image data is generated using a single buffer.
Is less likely to be generated.

Further, the moving picture reproducing apparatus according to the third aspect of the present invention is characterized in that the first compressed data required to generate the first image data and the second compressed image data required to generate the second image data. Moving image data including, in that order, second compressed data that is difference data and a plurality of third compressed data necessary to generate third image data that complements the two image data is input. Generating the first image data based on the first compressed data of the input moving image data, the second compressed data of the input moving image data and the second compressed data of the input moving image data, Based on the second image data generated based on the second compressed data that precedes the compressed data, or based on the first compressed data that precedes the second compressed data of the input moving image data Generated Generating the second image data based on the first image data and the third compressed data of the input moving image data and the third compressed data of the input moving image data before the third compressed data. Second image data generated based on certain second compressed data, or first image data generated based on the first compressed data of the input moving image data that precedes each of the third compressed data. Decoding processing including sequentially generating the third image data corresponding to each of the third compressed data based on the two pieces of continuous image data; The image data, the generated third image data, and the generated second image data are transferred to the display buffer in that order, and the image data stored in the display buffer is displayed. While performing the display processing including these transfer and display in parallel, the first
Image data, the respective third image data, and the second
For reproducing a moving image by displaying the first image data and the second image data in that order, and a second buffer for storing the first image data and a second buffer for generating the second image data. Aside from the buffer
Three third buffers, and the third image data is generated using all of the third buffers.

With this configuration, when moving image data is input, first image data of the moving image data is generated in the first buffer by decoding processing, and the second image data is stored in the second buffer. And the third image data corresponding to each third compressed data is sequentially generated in these third buffers while using all the third buffers.

The generation of the first image data is performed based on the first compressed data of the moving image data. The second image data is generated based on the second compressed data of the moving image data and the second compressed data preceding the second compressed data of the moving image data; Or the first of the moving image data before the second compressed data
And the first image data generated based on the compressed data. The generation of the third image data corresponding to each of the third compressed data includes generating the third compressed data of the moving image data and the second compressed data of the moving image data before the third compressed data. The second image data generated based on the first image data generated based on the first compressed data preceding the second image data or the respective third compressed data of the moving image data. This is performed based on the image data.

On the other hand, by the display processing, the first image data of the first buffer is transferred to the display buffer for display, and the third image data of the third buffer is transferred to the display buffer for display. Then, the second image data in the second buffer is transferred to the display buffer and displayed.

Therefore, in the third buffer, another third image data is generated immediately after the third image data is generated, as compared with the case where the third image data is generated using a single buffer.
Is less likely to be generated.

Further, the moving picture reproducing apparatus according to a fourth aspect of the present invention is the moving picture reproducing apparatus according to any one of the first to third aspects, wherein two adjacent third compression sections of the input moving picture data are provided. One of the third image data corresponding to the data is generated in one of the third buffers, and two of the third video data adjacent to the input moving image data are generated.
The other of the third image data corresponding to the three pieces of third compressed data is generated in a buffer other than the one buffer among the third buffers.

With such a configuration, one of the third image data corresponding to the two third compressed data adjacent to the moving image data is generated in one of the third buffers, and The other of the third image data corresponding to the two third compressed data adjacent to the data is generated in another of the third buffers.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 to FIG. 4 are diagrams showing an embodiment of a moving image reproducing apparatus according to the present invention.

In this embodiment, as shown in FIG. 1, a moving picture reproducing apparatus according to the present invention decodes moving picture data compressed in the MPEG format in a computer 100 using an OS operating in a multitask mode. This is applied to the case where is reproduced.

First, the structure of moving image data compressed in the MPEG format will be described.

The moving image data compressed in the MPEG format is
I data, which can decode image data alone, P data, which is difference data between two image data, and two B data necessary for decoding image data that complements between the two image data, Include in order. Here, the P data is image data decoded based on the I data or P data that precedes that of the moving image data and is difference data between two consecutive image data. In order to decode the data, the image data is required in addition to the P data. The B data is image data decoded based on I data or P data that precedes that of the moving image data, and is a complement necessary for decoding image data that complements between two consecutive image data. In order to decode the image data based on the B data, the image data is required in addition to the B data.

Next, the configuration of a computer system to which the present invention is applied will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of a computer system to which the present invention is applied.

As shown in FIG. 1, the computer 100 has a CPU 30 for controlling the operation and the entire system based on a control program, and a CPU 30
A ROM 32 storing a control program and the like for 30;
A RAM 34 for storing data read from the ROM 32 and the like and calculation results required in the calculation process of the CPU 30;
A CRTC 36 that converts data stored in a specific area of the RAM 34 into an image signal and outputs the image signal to the display device 44;
It is composed of a decoder 37 for decoding moving image data and an I / F 38 for mediating input / output of data to and from an external device, and these are mutually connected by a bus 39 which is a signal line for transferring data. It is connected so that data can be exchanged.

The I / F 38 includes, as external devices, an input device 40 such as a keyboard or a mouse capable of inputting data as a human interface, a storage device 42 for storing data and tables as files, and an image signal A display device 44 for displaying a screen based on the information is connected.

The RAM 34 is a VRAM that stores display data to be displayed on the display device 44 as a specific area.
The VRAM 35 includes a CPU 30 and a CR.
Access is possible independently with the TC 36.

The CRTC 36 reads the display data stored in the VRAM 35 sequentially from the head address at a predetermined cycle, converts the read display data into an image signal, and outputs it to the display device 44.

The decoder 37 outputs a predetermined time T (for example, 2
0 [ms]), the image data included in the moving image data is decoded.
When a decoding start command is received from U30 and moving image data from the I / F 38 or moving image data stored in the RAM 34 is input, the decoding process shown in the flowchart of FIG. 2 is executed until decoding of the moving image data is completed. It has become. FIG. 2 is a flowchart showing a decoding process performed by the decoder 37.

The decoding process is executed by the decoder 37.
Is executed, decoding is performed based on I data or P data.
Buffers A and B for storing image data to be loaded
Image data decoded based on one of the data
B for storing ₁And the other of the B data
For storing image data that is decoded based on
Buffer B_TwoAnd data based on I data or P data.
A buffer C for storing image data to be coded;
Are secured in the RAM 34, and as shown in FIG.
The process moves to step S100.

In step S100, I data or P
Buffer A as a buffer for storing image data to be decoded on the basis of the data, the flag F ₁ for selecting C, and as a buffer for storing image data to be decoded based on the B data buffers B _1, B ₂ set the flag F ₂ to select either "1", the process proceeds to step S102, and inputs the video data, the process proceeds to step S104, the moving image data is whether the I data input When it is determined that the moving image data is the I data (Yes), the process proceeds to step S105.

[0043] In step S105, determines whether the flag F ₁ is "1", when the flag F ₁ is determined not "1" (No), the image to be decoded on the basis of the I data It is determined that buffer A has been selected as the buffer for storing data, and the flow shifts to step S106.

In step S106, the image data is decoded into the buffer A based on the I data, and
107 goes to the flag F _1, is set to "1" indicating a selection of a buffer C as a buffer for storing image data to be decoded on the basis of the I data, the process proceeds to step S110.

In step S110, it is determined whether or not the input moving image data is P data. If it is determined that the moving image data is P data (Yes), the process proceeds to step S11.
2 proceeds to the flag F ₁ is equal to or a "1", when the flag F ₁ is determined to be "1" (Yes)
Determines that the buffer C is selected as the buffer for storing the image data decoded based on the P data, and shifts to step S114.

In step S114, the image data is stored in the buffer C based on the image data in the buffer A and the P data.
To step S116, and the flag F
_1, based on the P data is set to "0" indicating a selection of a buffer A as buffer for storing image data to be decoded, the process proceeds to step S118.

In step S118, it is determined whether or not the input moving image data is B data. If it is determined that the moving image data is B data (Yes), the process proceeds to step S12.
0 proceeds to, it is determined whether the flag F ₂ is "1", when the flag F ₂ is determined to be "1" (Yes)
Determines that buffer B ₁ is selected as the buffer for storing image data to be decoded based on the B data, the process proceeds to step S122.

[0048] At step S122, decodes the image data in the buffer B ₁ on the basis of the buffer A, C image data and B data, the process proceeds to step S124, the flag F _2, is decoded on the basis of the B data that as a buffer for storing image data indicating a selection of a buffer B ₂ is set to "0", the process proceeds to step S102.

Meanwhile, in step S120, when the flag F ₂ is determined to be "0" (No), the buffer B ₂ as a buffer for storing image data to be decoded on the basis of the B data has been selected Determine, step S12
Move to 6.

[0050] At step S126, decodes the image data in the buffer B _2, based on the buffer A, C image data and B data, the process proceeds to step S128, the flag F _2, is decoded on the basis of the B data that as a buffer for storing image data indicating a selection of buffer B ₁ is set to "1", the process proceeds to step S102.

On the other hand, when it is determined in step S118 that the input moving image data is not B data (No), the process proceeds to step S102.

Meanwhile, in step S112, when the flag F ₁ is determined not "1" (No), it is determined that the buffer A is selected as the buffer for storing image data to be decoded based on the P data , Step S130
Move to

In step S130, the image data is transferred to buffer A based on the image data in buffer C and the P data.
To step S132, and the flag F
_1, based on the P data is set to "1" indicating a selection of a buffer C as a buffer for storing image data to be decoded, the process proceeds to step S118.

On the other hand, if it is determined in step S110 that the input moving image data is not P data (No), the flow shifts to step S118.

On the other hand, in step S105, it determines that when the flag F ₁ is determined to be "1" (Yes), the buffer C is selected as the buffer for storing image data to be decoded on the basis of the I data And step S10
Move to 8.

In step S108, the image data is decoded into the buffer C based on the I data,
109 goes to the flag F _1, is set to "0" indicating a selection of a buffer A as buffer for storing image data to be decoded on the basis of the I data, the process proceeds to step S110.

On the other hand, if it is determined in step S104 that the input moving image data is not I data (No), the process proceeds to step S110.

Next, the configuration of the CPU 30 will be described.

The CPU 30 is composed of a micro-processing unit MPU and the like, and activates a predetermined program stored in a predetermined area of the ROM 32 upon activation.
An OS that operates with multitasking is executed. When decoding and displaying image data included in the moving image data and reproducing the moving image, the OS outputs a decoding start command to the decoding 37 to thereby decode the image.
In addition to executing the decoding process, a predetermined program stored in a predetermined area of the ROM 52 is activated, and the display process shown in the flowchart of FIG. 3 is executed in parallel with the decoding process according to the program. FIG. 3 is a flowchart showing the display processing executed by the CPU 30.

In the display process, the image data in the buffers A, B ₁ , B ₂ , and C is transferred to the display buffer every predetermined time T set to be the same as the predetermined time T in which the decoding process performs the decoding. This is a process of displaying the image data stored in the buffer. When the process is executed by the CPU 30, a display buffer for storing the image data to be displayed is secured in the VRAM 35, and as shown in FIG. First, the process proceeds to step S200.

In step S200, buffers A and B are used as buffers from which image data is transferred to the display buffer.
The flag F ₃ for selecting C is set to "1", the process proceeds to step S202, the flag F ₃ is equal to or "1", the flag F ₃ is "1" When it is determined (Yes), it is determined that the buffer A is selected as a buffer from which image data is transferred to the display buffer,
Move to step S204.

[0062] At step S204, and transfers the image data in the buffer A in the display buffer, the process proceeds to step S206, a flag F _3, selects a buffer C as a buffer to be image data transfer source to the display buffer Is set to “0”, indicating that the process proceeds to step S208.

[0063] At step S208, and transfers the image data in the buffer B ₁ in the display buffer, step S210
The process moves to, and transfers the image data in the buffer B ₂ in the display buffer, the process proceeds to step S202.

[0064] On the other hand, in step S202, when the flag F ₃ is determined not "1" (No), the buffer C as a buffer to be image data transfer source to the display buffer
Is determined to have been selected, and the routine goes to Step S212.

[0065] At step S212, the transferred image data in the buffer C in the display buffer, the process proceeds to step S214, the flag F _3, selects the buffer A as a buffer to be image data transfer source to the display buffer Is set to “1” indicating that the process is complete, and the process proceeds to step S208.

Next, the operation of the above embodiment will be described with reference to FIG. FIG. 4 is a diagram for explaining a moving image reproducing method according to the present invention. Hereinafter, the times t _{0 to} t ₁₃ indicate the times every elapse of the predetermined time T, that is,
Each of the times t _{0 to} t ₁₃ represents a time when a predetermined time T has elapsed from the immediately preceding time.

When the OS decodes and displays the image data included in the moving image data and reproduces the moving image, the CPU
The decoding process is executed by the decoding 37 by outputting the decoding start instruction to the decoding 37 by the decoding device 30, and the display process is executed in parallel with the decoding process. Here, the moving image data is I ₀ data, P ₁ data, B
₂ data, B ₃ data, P ₄ data, B ₅ data, B ₆ data, P ₇ data, B ₈ data, B ₉ data, I ₁₀ data,
B ₁₁ data, B ₁₂ data includes P ₁₃ data ... in that order.

[0068] In the decoding process, as shown in FIG. 4, at time t _0, step S102, S104～S10
9, the I ₀ data of the moving image data is input, and the input I ₀ data is decoded into the buffer A. At time t ₁ , the P ₁ data of the moving image data is input through steps S 102 and S 110 to S 116. , P ′ ₁ data which is image data is decoded by the buffer C based on the I ₀ data of the buffer A and the input P ₁ data.

Next, at time t ₂ , step S 1
02, through the S118～S124, is input B ₂ of the moving image data, I ₀ the data in the buffer A, buffer C P _'1
Based on the data and the input B ₂ data, B ′ ₂ data as image data is decoded by the buffer B ₁ , and at time t ₃ , steps S 102, S 118, and S 12 are performed.
Through 0, S126, S128, and is input B ₃ of video data, I ₀ the data in the buffer A, 'is image data based on _a data and input B ₃ data B' buffer C of P ₃ data It is decoded in buffer B _2.

Next, at time t ₄ , step S 1
02, S110, S112, S130, S132 through, P ₄ data of the moving image data is input, 'an image data based on _a data and input P ₄ data P' buffer C of P ₄ data buffer A Is decoded.

[0071] Then, at time t _5, step S1
02, through the S118~S124, B ₅ of the moving image data is input, the buffer A of P B _'5 data is image data on the basis of' ₄ data, buffer C of P _'1 data and input B ₅ data There are decoded in buffer B _1, at time t _6, step S102, S118,
Through S120, S126, and S128, the moving image data B
₆ is input, and B ′ ₆ data as image data is decoded to the buffer B ₂ based on the P ′ ₄ data of the buffer A, the P ′ ₁ data of the buffer C, and the input B ₆ data.

Then, at time t ₇ , step S 1
02, through the S110～S116, P ₇ data of the moving image data is input, 'P is image data on the basis of the _fourth data and the input P ₇ data' ₇ data is decoded in buffer C P Buffer A . The following data is decoded in the same manner.

On the other hand, in the display process, at time t ₁ ,
After steps S202 and S204, I _{0 of} buffer A
The data is transferred to the display buffer and displayed at time t.
In _2, through step S208, the B _'2 data buffer B ₁ is displayed is transferred to the display buffer,
At time t _3, through step S210, the B _'3 data buffer B ₂ are displayed are transferred to the display buffer.

Next, at time t ₄ , step S 2
02, S212 through buffer C of P _'1 data is displayed are transferred to the display buffer At time t _5, the through step S208, a B buffer B _1' to ₅ data is transferred to the display buffer At time t ₆ , B ′ _{6 of} buffer B ₂ is displayed via step S210.
The data is transferred to the display buffer and displayed at time t.
In _7, through steps S202, S204, P _'4 data buffer A are displayed are transferred to the display buffer. The following data is transferred and displayed in the same manner.

Therefore, even if the decoding process and the display process are out of synchronization due to a cause such as an increase in the processing load due to the execution of another process in the OS, the difference is within a range of twice the predetermined time T. For example, before the transfer of the B ′ ₂ data of the buffer B ₁ to the display buffer in the display process is completed, B ′ ₅
By decoding the data in the buffer B _1, the state that the non-transferred portion of the B _'2 data buffer B ₁ thus rewritten is not generated. This means that in Fig. 4, B _'3 data, B' ₅ data, B _'6
Data, B _'8 data, B' ₉ data, B The same is true for _'11 data and B' ₁₂ data.

As described above, in this embodiment, buffers B ₁ and B ₂ are provided separately from buffers A and C for storing image data decoded based on I data or P data. The image data is decoded based on the B data by using all of the buffers B ₁ and B ₂ .

[0077] Thus, the cause of such processing load by other processes in the OS is executed is increased, even if out of sync with the display process and decoding process, the image data in the buffer B ₁ in the display processing before been transferred to the display buffer by decoding the other image data in the buffer B ₁ in the decoding process, we can state that the untransferred portion of the image data in the buffer B ₁ will be rewritten to generate Performance can be reduced. This same is true for the buffer B _2.

Therefore, when the OS reproduces the moving image by decoding and displaying the image data included in the moving image data, it is possible to relatively prevent the reproduced moving image from flickering as compared with the related art. .

[0079] Further, in this embodiment, the image data for decoding the one of the image data corresponding to the two B data adjacent the moving image data in buffer B _1, corresponding to the two B data adjacent the moving image data the other of the so as to decode the buffer B _2.

As a result, the image data corresponding to the two adjacent B data of the moving image data is not continuously decoded into one buffer, so that the image data of the buffer B ₁ is stored in the display buffer in the display processing. before been transferred, by decoding the other image data in the buffer B ₁ in the decoding process, further reducing the likelihood of state occurs that the untransferred portion of the image data in the buffer B ₁ will be rewritten can do. This same is true for the buffer B _2.

Accordingly, when the OS reproduces the moving image by decoding and displaying the image data included in the moving image data, it is possible to further prevent the reproduced moving image from flickering.

In the above embodiment, I data corresponds to the first compressed data according to claims 1 to 3, P data corresponds to the second compressed data according to claims 1 to 3, The data corresponds to the third compressed data according to claims 1 to 4, the buffer A corresponds to the first buffer according to claims 1 to 3, and the buffer C corresponds to the third compressed data according to claims 1 to 3. Buffer B ₁ ,
B ₂ corresponds to the third buffer according to claims 1 to 4.

In the above embodiment, two buffers for storing the image data decoded based on the B data are provided, but the present invention is not limited to this.
Three or more buffers for storing image data decoded based on the data may be provided.

[0084] Thus, depending on the order of decoding the B data, prior to be completely transferred to the display buffer the image data in the buffer B ₁ in the display processing, decoding the other image data in the buffer B ₁ in the decoding process , the state that the non-transferred portion of the image data in the buffer B ₁ will be rewritten can be further reduced may occur.

Further, in the above embodiment, the case where the decoding process shown in the flowchart of FIG. 2 is performed by the internal process of the decoder 37 has been described. However, the present invention is not limited to this, and the CPU 30 may perform the decoding process. In this case, as in the above embodiment, a configuration may be adopted in which a control program stored in advance in the ROM 32 is executed, but a storage medium storing a program indicating these procedures is stored. Therefore, the program may be read into the RAM 34 and executed.

In the above embodiment, when executing the display processing shown in the flowchart of FIG.
The case where the control program stored in the ROM 32 is executed in advance has been described. However, the present invention is not limited to this, and the program is read from the storage medium storing the program indicating the procedure into the RAM 34 and executed. Is also good.

Here, the storage medium is a semiconductor storage medium such as a RAM or a ROM, a magnetic storage type storage medium such as an FD or HD, an optical reading type storage medium such as a CD, CDV, LD, or DVD, or an MO storage medium. A magnetic storage type / optical readout type storage medium includes any storage medium that can be read by a computer regardless of an electronic, magnetic, optical, or other read method.

Further, in the above embodiment, the moving picture reproducing apparatus according to the present invention, as shown in FIG. 1, uses a multitasking OS to decode moving picture data compressed in MPEG format in a computer 100. Although the present invention is applied to the case of reproducing a moving image, the present invention is not limited to this, and can be applied to other cases without departing from the gist of the present invention.

[0089]

As described above, according to the moving picture reproducing apparatus according to the first to fourth aspects of the present invention, the multi-task operating system generates and displays the image data included in the moving picture data to display the moving picture. When the reproduction is performed, even if the decoding process and the display process are out of synchronization as compared with the related art, before the image data in one of the third buffers is completely transferred to the display buffer in the display process, By decoding another image data into the one buffer in the decoding process, it is possible to reduce the possibility that a state in which an untransferred portion of the image data in the one buffer is rewritten will occur. The effect is obtained.

Further, according to the moving image reproducing apparatus of the fourth aspect of the present invention, the third image data corresponding to the two third compressed data adjacent to the moving image data is decoded into one buffer continuously. Before the transfer of the image data of one of the third buffers to the display buffer is completed in the display processing, the other image data is decoded into the one buffer in the decoding processing. In addition, the effect that the possibility that a state in which the untransferred portion of the image data in the one buffer is rewritten occurs, can be further reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a computer system to which the present invention is applied.

FIG. 2 is a flowchart showing a decoding process executed by a decoder 37.

FIG. 3 is a flowchart showing a display process executed by a CPU 30.

FIG. 4 is a diagram for explaining a moving image reproducing method according to the present invention.

FIG. 5 is a diagram for explaining a conventional moving image reproducing method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 computer 30 CPU 32 ROM 34 RAM 37 decoder 40 input device 42 storage device 44 display device

Claims (4)

[Claims] 1. Moving image data including first compressed data, second compressed data, and a plurality of third compressed data in that order is input, and the first compressed data of the input moving image data is input. And generating first image data based on the first compressed data of the input moving image data and the second compressed image data.
Generating the second image data based on the compressed data of the first and second compressed data of the input moving image data, the third compressed data, and the third compressed data based on the third compressed data. Third image data corresponding to the compressed data is sequentially generated, and the generated first image data, each of the generated third image data, and the generated second image data are displayed in that order. And a second buffer for generating the second image data, wherein the first buffer for storing the first image data and the second buffer for generating the second image data. A moving image reproducing apparatus comprising a third buffer, wherein the third image data is generated by using all of the third buffer. 2. An input of moving image data including first compressed data, second compressed data, and a plurality of third compressed data in that order, and the first compressed data of the input moving image data. Generating first image data based on the first moving image data, and generating second image data based on the first compressed data and the second compressed data of the input moving image data;
A third image data corresponding to each of the third compressed data is sequentially generated based on the first compressed data, the second compressed data, and the third compressed data of the input moving image data. Decoding processing including generation, transferring the generated first image data, the generated third image data, and the generated second image data to the display buffer in that order, The display processing including the transfer and display for displaying the image data stored in the image buffer is performed in parallel with the first processing.
Image data, the respective third image data, and the second
For reproducing a moving image by displaying the first image data and the second image data, and a second buffer for storing the first image data and a second buffer for generating the second image data. A moving image reproducing apparatus, comprising: at least two third buffers separately from the third buffer; and generating the third image data by using all of the third buffers. 3. Two sets of first compressed data required to generate the first image data, second compressed data that is difference data required to generate the second image data, and two images Input moving image data including a plurality of third compressed data necessary for generating third image data that complements data, in that order, and input the moving image data to the first compressed data of the input moving image data Generating the first image data on the basis of the second compressed data of the input moving image data and the second compressed data of the input moving image data preceding the second compressed data. Based on the second image data generated by the first moving image data or the first image data generated based on the first compressed data of the input moving image data before the second compressed data. Raw image data of 2 And the second compressed data generated based on the third compressed data of the input moving image data and the second compressed data preceding the third compressed data of the input moving image data. Image data or first image data generated based on first compressed data that precedes each of the third compressed data of the input moving image data and two consecutive image data. A decoding process including sequentially generating the third image data corresponding to the respective third compressed data, the generated first image data, the generated third image data, The generated second image data is transferred to the display buffer in that order, and the display processing including the transfer and display for displaying the image data stored in the display buffer is performed in parallel. An apparatus for reproducing a moving image by displaying the first image data, each of the third image data, and the second image data in that order, wherein the first image data is stored. And at least two third buffers separately from the first buffer for generating the second image data and the second buffer for generating the second image data. 3. A moving image reproducing apparatus characterized in that the moving image reproducing device generates the image data of (3). 4. The third buffer according to claim 1, wherein one of the third image data corresponding to two adjacent third compressed data of the input moving image data is stored in the third buffer. Generated in one of the buffers,
The other of the third image data corresponding to the two third compressed data adjacent to the input moving image data is generated in a buffer other than the one buffer among the third buffers. A moving picture reproducing apparatus characterized in that: