JP3444869B2 - Moving image data recording method and reproducing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of bit-compressing image data of a moving image and recording it on a recording medium such as a CD-ROM and a method of reproducing image data recorded by this method.

[0002]

2. Description of the Related Art For example, when recording digital image data of a moving image or a still image on a recording medium such as an optical disk,
It is desirable to record as much data as possible by making maximum use of the limited recording capacity. For this reason, the image data is compressed and recorded on the recording medium.

In order to compress this image data, D
VI (Digital Video Interactive) and MPEC (Mov
DCT (Discrete Cosi) of eing Picture Expert Group
A compression encoding method such as neTransform) has been proposed.

A CD-RO is used as a large-capacity recording medium.
M has been proposed and is used as an external storage medium in game machines and personal computers using microcomputers. When used for a game machine, moving image data is recorded in a CD-ROM, the moving image data is read out and loaded into a host computer, and a moving image (animation) is displayed on a CRT display.

In this case, in the conventional game machine, C
As a method of reading the moving image data from the D-ROM,
Instead of continuously reading moving image data from the CD-ROM and displaying moving images on the display, the CD-ROM
Is read appropriately to read out image data of a moving image composed of a plurality of frames recorded in a predetermined recording area of the CD-ROM, and a large-capacity R prepared in the host computer side is read out.
An animation is created from the image data for a plurality of frames stored in the RAM, and an animation is displayed.

[0006]

The above-mentioned conventional animation method for a game machine has a drawback in that the number of frames per second of a moving picture is small and a smooth animation cannot be obtained.

Further, it is important for a game machine to have an interactive property. For example, when the player attacks the enemy aircraft displayed on the screen, different screens must be prepared according to the result. That is, when a bullet hits an enemy aircraft, an image of the explosion pattern of the enemy aircraft must be displayed on the screen. On the other hand, when the attack fails,
On the screen, the image with the missed bullets against the enemy aircraft must be displayed on the display.

The above-mentioned interactivity is provided by the above-mentioned CD-
When trying to realize even the animation from the ROM, the screen of the explosion pattern and the screen of the attack failure must always be held together. At this time, for example, one screen, for example, the explosion pattern may be recorded in a separate special recording area, and the recording area may be appropriately seeked to display the explosion pattern screen according to the correspondence of the player. , This method is time consuming for seeking,
It impairs entertainment.

Therefore, for example, by adopting the image compression method as described above, it is possible to compress the image data more efficiently and always record the image data of two screens as one screen. Conceivable.

However, the conventional compression coding method as described above has a complicated coding algorithm. For example, a DCT or the like requires a product-sum operation (multiplication of floating-point numbers), resulting in a large-scale hardware configuration. In addition, a large-capacity memory is required for decoding, a special special chip is required, and a general-purpose DSP is used.
(Digital Signal Processor) cannot be used, and the decoder becomes expensive.

Further, since the data is compressed using the frame correlation of the image signal, if an error occurs at the time of decoding, there is a drawback that the influence of the error propagates to other frames. Further, when the compression rate is large, there is a problem that the image quality is deteriorated.

An object of the present invention is to provide a recording method capable of always recording image data at an optimum compression rate and having a simple decoding process. Another object of the present invention is to provide a method of recording image data that enables a plurality of screens to be switched instantaneously in response to a user's response, such as a game. Furthermore, the present invention provides a reproducing method of a recording medium recorded by the recording method.

[0013]

In order to solve the above-mentioned problems, the image data recording method according to the present invention performs a data compression process in accordance with the properties of pixels forming an image,
When the number of bits per pixel is compressed and the compressed image data is recorded on a recording medium which moves a recording position at a predetermined speed, the compressed image data of the recording medium is compressed according to the amount of recording information of the image to be recorded. The moving speed is changed and recorded, and information for identifying the recording position and the moving speed where the moving speed is changed is recorded on the recording medium.

Further, when a plurality of images are recorded in parallel, the moving speed of the recording medium is changed according to the number of the images to be recorded.

[0015]

Since the moving speed of the recording medium is changed and recorded according to the amount of recorded image information or the number of images to be recorded, the data compression efficiency can always be optimized.

Since information for identifying the moving speed at the time of recording is recorded on the recording medium, at the time of reproduction,
Based on this information, the moving speed of the recording medium during reproduction can be determined.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method of recording image data according to the present invention and a method of reproducing a recording medium recorded by this recording method will be described below with reference to the drawings. In this example, the recording medium is a CD-ROM, and the image reproducing device is a game machine. Further, this is an example in which the normal speed (1 × speed) and the 2 × speed can be selected as the rotation speed of the CD-ROM disc.

In the image reproducing apparatus of this example, as will be described later, the moving image is reproduced while continuously reading the image data from the CD-ROM to realize an animation with a large number of frames and a smooth motion, and the moving image is also reproduced. Is divided into a background and a foreground, and images in the foreground can be switched instantaneously so that an image having an interactive property can be reproduced.

[Encoder Device for Executing Image Data Recording Method] FIGS. 1 and 2 are block diagrams of an example of an apparatus for executing the image data recording method of this example. In this example, the compressed image data is recorded on the CD-ROM. This CD-ROM is used as software for a game machine as described later, and image data is highly efficiently compressed so that a moving image can be reproduced.

In this example, one frame (one screen)
3A includes, for example, horizontal × vertical = 256 pixels × 144 pixels, and one pixel has three primary colors R,
G and B are each represented by 8 bits. Then, the original image data is subjected to data compression processing in the unit of one frame as follows. It should be noted that data in units of frames is subjected to preprocessing such as dither to limit the number of colors in a frame in advance so that vector quantization to be described later can be facilitated.

That is, the moving image data VA in frame units is supplied to the difference calculating means 23 through the input end 21, and the image data BG of the background image of this moving image is supplied to the difference calculating means 23 through the input end 22. To be done. The difference calculating means 23 obtains the difference between the moving image frame and the background image frame, and detects the background portion (the portion having no motion in one frame of moving image) from the moving image frame. Then, the portion corresponding to the detected background is made a transparent color (the pixel value is (R, G, B) = (0, 0, 0), for example). The output data of the difference calculating means 23 is supplied to the character dividing means 24.

When there is no moving image data input from the input end 21 and only the background image data BG from the input end 22, the difference calculating means 23 is bypassed and the background image data BG is divided into characters. Is supplied to the means 24.

In the character dividing means 24, as shown in FIG. 3B, one frame image is divided into small area blocks (horizontal × vertical = 8 pixels × 8 pixels) (hereinafter, this block is referred to as a character). Therefore, FIG.
As shown in B, the data of one frame image is 3
2 × 18 = 576 character image data C (0)-
It is divided into C (575). These character data include data in which 64 pixels are all the transparent color. A character consisting only of transparent pixels will be called a null character.

The image data C (0) to C (575) of the character for one frame from the character dividing means 24 is
The null characters are supplied to the null character deleting means 25 to delete the null characters, and the number of characters per frame is reduced. The reduced character data C (0) to C (N) from the null character deleting means 25 (N <57
6) is supplied to the pallet dividing means 26. Further, information regarding the screen position of the deleted null character is supplied to the screen table creating means 32 of FIG. 2 described later.

The palette dividing means 26 classifies characters into eight groups (each group is referred to as a palette) in this example by collecting characters having similar colors according to the color distribution within the character. For example, as shown in FIG. 3C, groups of characters having similar color tones depending on the contents of the image are A, B, C, D, and
If it occurs like E ..., this group A, B,
A palette is constructed for each of C, D, E ....

In the case of this example, the method of allocating eight palettes is as follows: (1) The representative color of each character (for example, the average value of the colors in the character) is calculated, and it is assumed that each character consists of the representative color. . (2) Vector quantization is performed, and the representative colors of all characters in one frame are quantized into eight colors. That is, since the number of characters is N, the maximum number of representative colors of the character is N.
Expressed as a representative color. Although various proposed methods can be used as the vector quantization method, in this example, when the three-dimensional color space is considered with the color components of the three primary colors of red, blue, and green being orthogonal to each other, each character The distance between the representative colors in the color space is calculated, and the characters of the representative colors having a short distance from each other are put together, that is, the characters of the similar representative colors are put together. (3) Characters having the same label (representative color) are put together into one palette. It is performed in three steps.

The group of characters forming each palette does not have to be a continuous character area, and scattered characters may form one palette group.

Data P (0) to P (7) of eight pallets
(Each data P (i) is composed of one or a plurality of character data, and each character data is 24-bit color data) is temporarily stored in a register and supplied to the vector quantizing means 27. Further, information on the positions of the respective palettes and the characters contained therein on the screen is supplied to the screen table creating means 32 of FIG. 2 described later.

In the vector quantizing means 27, similarly to the case of the palette division described above, the pixels of a plurality of characters in each palette are collectively treated as one representative color for pixels of similar colors. The representative color of the 15-color pixel is determined. Then, the summarized pixels of similar colors are replaced with the representative color. At this time, 1
If the number of colors of pixels in one palette is more than 15 colors, vector quantization is further performed to round the pixels in the palette to 15 colors or less. Then, the resulting 15 or less colors are set as the representative colors of the pixels of the palette.

In this way, from the vector quantizing means 27, the data P '(0) to P' (7) in which the respective pixel data of the characters in each palette are replaced by the representative colors of 15 colors or less of that palette. Is obtained. By this vector quantization processing, the color of the pixel in each character included in the data P '(0) to P' (7) becomes 15 colors or less, and a single-color character in which all the pixels are the same is also included. Occurs.

The image data P '(0) to P' (7) in character units of 8 palettes, each of which is rounded to 15 colors or less, from the vector quantizing means 27 are supplied to the labeling means 28. It This labeling means 2
In FIG. 8, color conversion tables COL (0) to COL (7) of 15 colors or less than 15 color data selected as representative colors of pixels for each palette are created and temporarily stored in the register (see FIG. 4). .

In this case, each color conversion table COL (j)
Consists of 16 colors of color numbers 0 to 15. No color is assigned to color number 0 of each color conversion table COL (j), and the pixel represented by this color number 0 is It is specified to be displayed as transparent.

Color data of color numbers 1 to 15 are shown in FIG.
As shown in, each of red R, blue B, and green G is represented by 5 bits. Actually, a 1-bit dummy is added to make 16 bits (2 bytes).

This color conversion table COL (0) to COL
The data of (7) is supplied to the data amount calculating means 30 as shown in FIG.
It is supplied to the M encoder 31.

Further, the labeling means 28 uses the color conversion table COL for the pixels of the character of each palette.
(0) to COL (7) are referred to, and each pixel data is converted into label image data in which the color of the pixel is represented by the corresponding color number on the color conversion table of the palette including the pixel. It In this case, since the color numbers are 1 to 15, the label image data is represented by 4 bits.

Thus, for the character data of the palette P (0), the label image data LAB (0, a) (a = 0,1,2, ...) Each consisting of 4 bits is converted into the palette P (1).
Label image data LA
B (1, b) (b = 0,1,2, ...) is the label image data LAB (7, for character data of palette P (7).
g) (g = 0,1,2, ...) are obtained respectively. Then, the label image data LAB (0, a) to LAB (7, g) are supplied to the monochromatic character deleting means 29.

The monochromatic character deleting means 29 deletes monochromatic characters from the image data. And
Data LAB (0) to LAB in which character data of one frame in which a monochrome character is deleted are sequentially packed in advance.
(M) (M <N <576) is supplied from the monochrome character deletion means 29 to the data amount calculation means 30, and
It is supplied to the CD-ROM encoder 31.

Further, from the monochromatic character deleting means 29, information on the position of the deleted monochromatic character on the screen is obtained and supplied to the screen table creating means 32.

In the screen table creating means 32, 1
A screen table scr is formed of information SCR0 to SCR575 for rearranging the characters of the frame to the original positions on the screen. Each information SCRk (k = 0,1,2 ..., 575) of this screen table scr is
As shown in FIG. 5, the screen of one frame is divided into small areas of the same size as the character, and the character number (10 bits) of the character displayed in each small area (the character number is recorded in advance). It is configured by defining a character order of compressed data) and a palette number (3 bits). In the case of this example, each information SCRk is
As shown in FIG. 5, it is composed of, for example, 2-byte data.

The character number is the character rank in the recorded data of one frame of the character to be displayed at the position of the small area. Further, the palette number indicates which of the eight palettes the character displayed in the small area is included in. That is, it indicates which color conversion table is used for decoding.

In the case of this example, 0 of the character numbers is assigned to the null character. On the decoding side, on the screen table scr, the small area having the character number 0 may be determined to be the same as the background color and displayed as transparent. Therefore, the null character pixel data is not recorded as compressed image data by recording the control data in the screen table scr.

Character numbers 1 to 15 are
Only assigned to monochromatic characters. That is, when the character displayed at the position of a certain small area in the screen table scr is a monochromatic character, the palette number is assigned to that small area in the same manner as for other recorded characters. Instead of the number, one of the color numbers 1 to 15 in the color conversion table of the palette including the single color character is assigned. As a result, the color (single color) of the small area is determined. Therefore, even a single-color character is not recorded as compressed image data for each character to be described later by registering and recording the color data of the character in the screen table scr as described above.

From the above, since the character is a null character and a monochromatic character, the character number for the character of one frame of the compressed image data recorded in advance is recognized to start from number 16, and the data SCRk of the screen table is recognized. Recorded inside. That is, the screen table data SCRk of the small area in which the head character of one frame is to be arranged is 16 as the character number, and the screen table data SCRk of the small area in which the second character is to be arranged is , 17 is recorded as the character number.
Originally, 10 bits are allocated to the character number, so there is a sufficient margin for shifting such a number.

The data of the screen table scr from the screen table creating means 32 is supplied to the data amount calculating means 30 and at the same time recorded as CD-data as recording data.
It is supplied to the ROM encoder 31.

The CD-ROM encoder 31 processes one frame of image data as one block, but the recorded data is managed in sector units according to the CD-ROM format.

For example, the sector when the recording mode of the CD-ROM is the mode 1 is as shown in FIG. That is, a sync (synchronization) pattern is arranged at the head of the sector, and subsequently, a header including a sector number, a track number, etc. is arranged. The header is followed by 2 Kbytes of user data, and the end of the header is auxiliary data including error detection and error correction codes of the user data.

In the case of this example, the moving image data, the background image data and other data are recorded in the user data area of the sector. The 32 bytes at the beginning of the 2 Kbytes of user data are identification information IDs.
It is said that The identification information ID indicates what kind of data is recorded in the user data area of each sector, and includes information indicating how many sectors of one frame of data continue. It also includes information on the rotational speed during recording on the CD-ROM disc. In this identification information ID,
Of course, other information can be included.

In the case of this example, as the content of the data indicated by the identification information ID, the user data of the sector is the image data of one moving image, the color conversion table and the screen table scr, as will be described later. Information, background image data, program data and other control data are prepared.

In the case of this example, in order to realize a smooth motion animation, for example, 15 frames (frames) / second are set. In the format of the CD-ROM, when the rotation speed is 1 × speed, it is 75 sectors / sec. Therefore, if the recording data is configured as 5 sectors / frame, a moving image of 15 frames / sec is possible. Also, CD
-If the rotation speed of the ROM disk is doubled, it will be 150 sectors / second, so if the recorded data is composed of 10 sectors / frame, a moving image of 15 frames / second can be realized.

The data amount calculation means calculates the amount of data to be transmitted as image data for one frame from the input data, and rotates the disc during recording and reproduction in order to realize the animation of the number of frames. As speed
Decide whether to select 1x or 2x speed. Then, the selected rotation speed selection information is CD-RO.
The information ID for identification, which is supplied to the M encoder 31 and described above.
Recorded on the disc as part of the. Further, the selection information of the determined rotation speed is supplied to the drive system of the CD-ROM disc, and the motor is controlled to drive the disc at the determined rotation speed.

In the case of this example, the data amount relating to the moving image compressed as described above is
It can be calculated as follows.

Since there are 8 pallets per frame,
The total color conversion table is 16 (color) × 8 (palette) × 2 (byte) = 256 (byte). Further, since the screen table scr has 2 bytes per character, 576 × 2 (bytes) = 1152 (bytes).

Therefore, the total data amount of the color conversion table and the screen table scr is 2 Kbytes or less, which is within one sector.

Further, the image data of the moving image changes depending on the ratio of the null character and the single color character to the character recorded as the compressed data. 1 character is 6
It consists of 4 pixels, and each pixel is compressed and recorded as 4-bit data, so the amount of data per character is 32.
It is a byte. Therefore, when the recording character: null character: single color character = 2: 2: 1, 32 × 576 × 2/5 = 7372.8 bytes, which fits within four sectors.

In this case, as shown in FIG. 7, the data relating to the moving image can be recorded in the CD-ROM as 5 sectors for each frame. Therefore, the CD
The rotation speed of the ROM disc is determined to be 1 × speed.
Then, the CD-ROM encoder 31 allocates the user data of the first 4 sectors of the 5 sectors to the character data from the monochrome character deleting means 29.
Then, in the fifth sector shown by hatching in FIG.
Data of the screen table scr and the color conversion table are assigned.

In this case, as the identification information ID of 32 bytes in the user data area of each sector, in the first 4 sectors, information indicating that the image data is a moving image and the number of sectors following it ( 4 for the first sector
Is recorded), information about the disk rotation speed and the like are recorded.
In the last fifth sector, information indicating that it is data of the screen table scr and the color conversion table and information of the number of sectors following it (in this case, 1
Is recorded), information about the disk rotation speed and the like are recorded.

Further, when the recording data amount for one frame exceeds four sectors, the data amount calculating means 30
Then, it is determined to be double speed. Then, the required number of sectors is assigned as one frame. In this example,
The rotation speed can be changed in units of one frame.

Then, the recording data from the CD-ROM encoder 31 is led to the terminal 34 via the recording circuit 33, and the CD-RO on the rotation side determined as described above.
Recorded in M.

In the above example, the case where the disk rotation speed can be changed to the 1 × speed and the 2 × speed has been described, but the disk speed is 1.5 × and 2.5 × as required. The speed can be set to double speed or triple speed.

By the way, the background image data BG is compressed in the same manner as the moving image data and recorded in the CD-ROM. However, the image data of the still image of the background image has a compression rate because a null character does not occur. Get lower. However, since it is a still image, it is not necessary to increase the number of frames per second, and it is possible to record as an appropriate number of sectors. In addition, when decoding, a separate memory area for the background image is prepared, and the background image data is always read from that memory until the background image changes to another scene. Can be obtained. Therefore, in this example, only when the scene changes, the background image data B
G is recorded on the disc in the required number of frames, for example, two frames, an odd frame and an even frame, between moving image data in frame units.

In addition to the compressed image information as described above, a program for decoding the compressed image information and a game program are recorded on the CD-ROM. Furthermore, audio information is also recorded as appropriate.

These program data are recorded separately from the above-mentioned data so that they can be collectively read out at the time of decoding, prior to the reproduction of a moving image or the like. Note that these program data can also be recorded in the middle of the moving image data in units of 5 sectors as data other than the image data of the moving image in the above example, in the same manner as the still image recording method described later. .

According to the data compression method described above, 1
The image is hierarchically divided into small areas in frame units, and the vector quantization is performed on the image data of each layer, so that the compression rate of the image data can be increased. Since the disk speed can be changed according to the amount of data, the data can be recorded at the optimum compression rate.

In the case of this example, one group (palette) is formed by grouping characters having similar colors, and a plurality of such groups are formed for one screen, and the image data is palette (group). It is divided. Then, since the vector quantization processing is performed within the palette composed of image portions of similar colors, the quantization error is reduced.

Further, when the image data is encoded in this way, the decoding process can be performed only by referring to the table at the time of decoding, so that the structure of the decoder is simplified. Further, since a large capacity buffer memory is not required, a general-purpose DSP having a limited capacity of the built-in RAM can be used as a decoder, and the cost of the decoder can be reduced.

Moreover, since the compression processing is performed without utilizing the frame correlation, even if an error occurs during decoding, the error is completed within one frame and does not affect subsequent frames.

Further, since the decoder circuit can be provided at a low cost and a CD-ROM can be used as a recording medium, it is effective when applied to software of a computer game machine.

In the above example, when recording a moving image, data of a character that is the same as the background image (still portion) or has one color is registered in the screen table scr and only color data is transmitted. Since data in pixel units is not transmitted, traffic on the data transmission path can be reduced.

[Description of Decoding Device as One Embodiment of Image Reproducing Device] Next, the CD compressed as described above will be described.
An example of a device for decoding the image data recorded in the ROM will be described in the case of a game machine.

That is, FIG. 8 shows an example of a game machine using a microcomputer, 1 is the main body of the game machine, 4 is a sub-processing unit, 5 is a CD-ROM, 6 is a program cartridge, and 7 is a voice. It is the main processing unit of data.

The game machine body 1 is composed of a microcomputer, 11 is its CPU, 12
Is a DMAC (DMA controller), 13 is a work area RAM, 14 is a PPU (picture processing unit), and 15 is a video RAM.

Then, the game machine main body 1 has the first and second
It has a two-bus configuration including the system buses 18 and 19 of FIG. The two system buses have a common data bus, but the address buses are the first system bus and the second system bus.
The system bus is separate. And DMAC
12, the DMA transfer is possible only between the first and second system buses 18 and 19.

In this case, the CPU 11 and the second system bus 19 are connected to each other via the port 16.
The devices connected to the first and second system buses 19 can be accessed via the port 16.

The first system bus 18 has a CPU 1
1, the DMAC 12 and the RAM 13 are connected. Also,
The second system bus 19 has a DMAC 12 and a PPU.
14 is connected and video RAM is connected to the PPU 14.
15 and the CRT display 6 are connected. Further, the sub-processing unit 4 and the main processing unit 7 for audio data are connected to the second system bus 19.

In the case of this example, the video RAM 15 is divided into a plurality of memory areas M1 to M4, for example, as shown in FIG. In this example, M
1, M2 and M3 are each a memory area (memory plane) for reproducing one image. Each of these memory areas M1 to M3 has a screen area of two frames (two screens), and the image data of one screen area is read by the PPU 14 in synchronization with vertical and horizontal scanning of the CRT display 8. While being displayed, it is displayed as an image on the display 8. While this display is being performed, the image data of the image to be displayed next is written in the other screen area.

In the case of this example, as will be described later, the memory area M1 is used as a memory area for a background image. The memory area M2 is used as a memory area for the foreground image.

The memory area M4 is a work area of the PPU 14 and is used as an area for the screen table scr, the color conversion table, and other data.

Further, in the main processing unit 7 of the audio data of the game machine body 1, 71 is the APU (audio
Processing unit), 72 is a D / A converter,
Reference numeral 73 denotes an audio output terminal, which connects the APU 71 to the bus 19 and the D / A converter 72.
When the audio data and the program for decoding the audio data are loaded into the APU 71, the audio data is decoded into a digital audio signal, and the digital audio signal is D / A converted into an analog audio signal by the converter 72, and then the output terminal. It is output to 73.

The sub-processing unit 4 has a CD player to enable the use of the CD-ROM 5, and
1 is the CD player, 42 is DSP, 43 is CD-R
OM decoder, 44 is RAM for the work area, 4
Reference numeral 5 is a controller. Audio data and image data are recorded in the CD-ROM 5, and these audio data and image data, especially image data, are compressed as image data by the above-described method and recorded.

The DSP 42 is for performing error correction on the reproduction signal of the player 41 and separating user data such as image data and control data such as track number from the reproduction signal.
5 is the control data from the DSP 42 and the CPU 11
Control the player 41 based on the instruction data from
It is for reproducing target data. Also,
The decoder 43 outputs the reproduction signal of the player 41 to the CD-RO.
This is for performing processing such as error correction for the CD-ROM when the reproduced signal is M5.

Further, in this example, a general-purpose DSP 50 is provided in the processing unit 4, and when necessary, this DS 50 is used.
P50 allows a part of the processing of the CPU 11 to be borne. Although the processing unit 4 is integrated with the game machine main body 1 in this example, it may be in the form of an adapter for the game machine main body 1.

The program cartridge 6 is used by inserting it into the slot 2 of the game machine main body 1 when using this game machine. When the CD-ROM 5 is not used, this program cartridge 6 is a general-purpose game software, and is inserted in the CD-ROM.
When using 5, a dedicated one is inserted.

The cartridge 6 has a ROM 61
And a RAM 62, and in the case of a cartridge for the CD-ROM 5, the ROM 61 includes the CD-ROM 5
A program for a so-called initialization process for the game machine main body 1 to capture the recorded data of 1 to execute the game is written. Further, the RAM 62 is used for holding various data regarding the state at that time, for example, when the game is temporarily interrupted midway, and is backed up by the battery 63.

Then, when the cartridge 6 is inserted into the slot 2 of the game machine body 1, the ROM 61 and the RAM 62 are connected to the bus 18 through a connector (not shown).

Then, the program of the ROM 61 of the cartridge 6 is executed by the CPU 11, and the CD-ROM 5
Data is taken into the RAM 13 of the game machine body 1 and the identification information ID in the user data of each sector is decoded. Then, from the identification information ID, the rotation speed of the CD-ROM disc at the time of recording the data of the frame to be decoded is determined, and the content of the image data of the frame, for example, moving image data,
It is determined whether the image data is background image data, and the decoding process of each user data is performed based on this. That is, the rotation speed during playback is made to match the rotation speed during recording,
The animation image is reproduced and displayed.

That is, a CD-
When the data is reproduced from the ROM 5, the reproduced data is sequentially supplied from the player 41 to the DSP 42 and the decoder 43 and subjected to processing such as error correction, and the error-corrected data is output from the decoder 43 by the DMAC 12. DMA in the first buffer area of RAM 13
Transferred.

Next, the CPU 11 checks the identification information ID of each sector of the data taken into the RAM 13. Based on this check result, the CPU 11
Performs a decoding process procedure according to the disc rotation speed and image content indicated by each ID.

Incidentally, from the CD-ROM 5, the RAM 13 is loaded with the above-mentioned decoding processing program and game program prior to the reproduction of image data and the like.

[Decoding process of moving image data] CP
As a result of checking the identification information ID in U11, when it is determined that the content of the user data in the sector is image data of a moving image, the decoding and display processing of the moving image is performed as follows.

That is, (1) One frame of image data is reproduced from the CD-ROM 4 by the CD player 41, and this image data is
The player 41 sequentially supplies them to the DSP 42 and the decoder 43 to perform processing such as error correction, and the error-corrected image data is DMA-transferred from the decoder 43 to the buffer area of the RAM 13 by the DMAC 12.

(2) DM in the buffer area of RAM 13
The label image data (color number data) of the A transferred image data is DMA-transferred to the video RAM 15 through the PPU 14 by the DMAC 12 during the vertical blanking period of the CRT display 6.

(3) When the processing of (2) is completed, the screen table scr of the image data DMA-transferred to the buffer area of the RAM 13 is transferred to the PPU by the DMAC 12 during the vertical blanking period of the CRT display 6.
DMA transfer is performed to the video RAM 15 through 14.

(4) The color conversion table COL (j) of the image data DMA-transferred to the buffer area of the RAM 13 during the horizontal blanking period of the CRT display 6.
But the video RA through the PPU 14 by the DMAC 12
DMA transfer is performed to M15.

(5) When the above processing is performed, PPU1
4 refers to the color conversion table COL (j) in real time, and the color number data transferred by (2)
The pixel data is converted into actual color pixel data, and this pixel data is written in the address corresponding to the original character position in the video RAM 15 by referring to the screen table scr.

(6) When pixel data for one frame is written in the video RAM 15 as described above, the video RAM 15
The display area 15 is switched, the area in which the pixel data is written is activated, and the image of the activated area is displayed on the display 6.
At this time, the data SCRk of the screen table scr
All the pixel data of the small area having the character number of 1 to 15 is the pixel data of one color in the color conversion table of the palette number. Further, all the pixels in the small area (null character) having the character number 0 of the data SCRk of the screen table scr are made transparent.

(7) The process returns to (1), and thereafter, the processes of (1) to (6) are repeated for each frame.

The image data reproduced from the CD-ROM 4 is sequentially sent from the RAM 13 to the video RAM 15 through the PPU 14 and also the PPU 14
Is reproduced. Therefore, an image based on the image data of the CD-ROM 4 is displayed as a moving image on the display 6. Since the null character portion is transparent, the background image is displayed.

[Processing of Still Image Data] The reproduction data from the CD-ROM 5 is as shown in FIG. 10, and as shown by hatching in the figure, one frame (5 sectors) of the moving image data is shown. If a sector of still image data is inserted between the two), the start pointer PS of the processing of the still image data is started at the beginning of the inserted still image data.
When the data processing is started, the decoding processing of the moving picture described above is stopped, and the moving picture remains the previous screen.

Then, with respect to the still image data, the identification information ID of the sector is checked by the CPU 11,
The rotation speed and the number of consecutive sectors are detected from the identification information ID. When the sector of the still image data ends,
The end pointer PE rises, and the data processing ends. If the subsequent sector is a moving image sector, the process of decoding the moving image data is restarted. Therefore, the video continues from the previous screen. In this case, for example, 5 sectors = 1/15 seconds, and the insertion period of other data is a short period, so that the moving image visually appears almost continuous.

The still image data is processed as follows and written in the memory area M2 of the video RAM 15.

(1) First, the CPU 11 checks the identification information ID of the user data of the sector to determine that the sector is a still image, and the sector following the still image is shown in FIG. 10, for example. As described above, when it is determined that the number of sectors is 5, the start pointer PS and the end pointer PE indicate these 5 sectors, and the above-described moving image decoding process temporarily shifts to a still image processing process. Then, the instruction is given from the CPU 11 to the PPU 14.

(2) Then, the image data of the still image that has been DMA-transferred to the RAM 13 is DMA-transferred to the memory area M2 of the video RAM 15 via the PPU 14.

(3) The PPU 14 converts the image data of this still image from 4 bits to 1 in the same manner as in the case of the moving image described above.
Decoding processing for returning to 6-bit data is performed, and the decoded still image data is rewritten in the memory area M2.

(4) As described above, when one frame of pixel data is written in the memory area M1 of the video RAM 15, the display area of the video RAM 15 is switched and the area in which the pixel data is written is made active. The image of the background image of the determined area is displayed on the display 6.

The still picture decoded as described above is combined with the moving picture to be the background of the moving picture.

Thus, the CD-ROM records the identification information ID for each sector, which indicates the content of data and the number of sectors in which data of the same content continues. Therefore, the decoding device monitors the identification information ID. By doing so, the decoding process for each sector can be performed. Therefore, a sector of a still image or other data can be inserted and recorded between image data of a moving image in which one frame includes a plurality of sectors, and a large amount of data other than the moving image can be inserted in the moving image data. Will be possible.

As for the moving image, if the previous screen is held during the period of the other data, the moving image follows the period of the other data, so that the moving image can be reproduced without visually stopping.

Further, according to the example shown in the figure, the CPU 11 manages the flow of all data so that the CD-ROM
Since the CPU 11 absorbs the asynchronousness between the reading of the image data of No. 5 and the processing of the CPU 11, the CD-ROM 5
The image data can be read continuously.
Moreover, the structure therefor is simple as is apparent from FIG.

The above is the case where the rotational speed of the disc is changed according to the amount of image data to be recorded as one frame for recording / reproduction. When recording a plurality of moving images in parallel, the moving images to be recorded in parallel are recorded. The rotation speed of the disc may be changed according to the number of the.

FIG. 11 is a diagram for explaining the recording data and the rotation speed in that case. In the case of scene A, the first moving image U (n) (n = 0) is displayed after the background image BG1. ，
1, 2, ...) and the second moving image V (m) (m = 0,1,
2, ...) are recorded alternately for each frame.
In this case, the number of null characters and monochromatic characters generated by vector quantization is large, and one frame of data of each moving image can be recorded in one sector to two sectors. Therefore, the data of this scene A is recorded in a state where the rotation speed of the disk is 1 × speed.

In the case of scene B, after the background image BG2, the first moving image U (n) (n = 0, 1, 2, ...) And the second moving image V (m) (m = 0, 1, 2, ...), a third moving image X (k) (k = 0,1,2, ...), and a fourth moving image Y (l) (l = 0,1,2, ...). Image data of four types of moving images are sequentially recorded in units of four frames, one frame for each. In this case, the data of this scene B is recorded in a state where the rotation speed of the disk is double speed.

At the time of decoding, for example, in the case of scene A, the CD-ROM disc 5 is rotationally driven at 1 × speed, and either the first moving image U (n) or the second moving image V (m) is displayed. One of them is selected and read from the RAM 13 according to the input operation condition of the game player, and is displayed on the display 8 after being combined with the background image BG1.
That is, for example, when the enemy aircraft is shot down by the player's attack, for example, the animation based on the explosion pattern of the first moving image is selected and displayed on the display 8, and when the attack by the player fails, the second moving image of the second moving image is displayed. , An animation according to the flight pattern of the enemy aircraft is selected and displayed on the display 8.

In the case of scene B, a CD-ROM
The disk 5 is rotationally driven at a double speed, and one of the first moving image U (n) to the fourth moving image Y (l) is selected according to a given condition such as input by the player,
It is combined with the background image BG2 and displayed as an animation on the display.

As described above, on the display 8,
A combined image in which the background and the moving image as the foreground are combined is displayed. According to this example, since the disc rotation speed can be varied and a plurality of necessary moving images can be recorded in parallel in a so-called interleaved state, the CD-ROM is always rotated at a predetermined rotation speed. It is possible to selectively extract a moving image from the plurality of moving images and display it on the display while playing back the image.

In this case, as a foreground moving image, for example, a plurality of screens to be switched according to the user's response, such as the flight pattern of the enemy aircraft and its explosion pattern, are prepared. Just select which one to display as the foreground on the decoding side,
Switch instantly. Therefore, it is possible to realize a game machine that has both interactivity and entertainment.

Although the background image has been described as a still image in the above example, the still image can also be a moving image. In that case, the background image may be a frame dropping animation in consideration that human attention is less likely to be paid compared to the foreground.

In the above example, the rotational speed information at the time of recording on the CD-ROM is recorded for each sector so that the position where the speed is changed can be identified. As the data, the rotation speed and the disk position at which the rotation speed is switched may be recorded.

The recording medium is not limited to the CD-ROM, but a tape or the like can be used.

[0119]

As described above, according to the present invention, the speed at the time of recording on the recording medium is changed according to the amount of image data to be recorded and the number of images to be recorded, and recording is performed. Therefore, it is possible to perform recording on the recording medium without increasing the data compression amount. Therefore, image data can always be recorded with optimum data compression efficiency.

Since the information about the medium speed and the speed change position at the time of recording is recorded on the recording medium, the speed at the time of reproducing the recording medium can be switched at the time of reproducing, Good reproduction can be performed.

[Brief description of drawings]

FIG. 1 is a part of a block diagram of an embodiment of an encoding device used in a recording method according to the present invention.

FIG. 2 is the rest of the block diagram of one embodiment of the encoding device used in the recording method according to the present invention.

FIG. 3 is a diagram for explaining an image division method according to an embodiment of a data compression method used in an example of the present invention.

FIG. 4 is a diagram for explaining a table used in an embodiment of an image compression method used in the examples of FIGS. 1 and 2;

FIG. 5 is a diagram illustrating a table used in an embodiment of an image compression method used in the examples of FIGS. 1 and 2;

FIG. 6 is a view for explaining a sector format of a CD-ROM and an identification information ID recorded for each sector by an example of a recording method according to the present invention.

FIG. 7 is a diagram showing an example of reproduction data from a recording medium recorded according to the present invention.

FIG. 8 is a block diagram of an embodiment of a decoding device used in the reproducing method according to the present invention.

FIG. 9 is a diagram for explaining a memory used in the example of FIG.

FIG. 10 is a diagram showing an example of reproduction data.

FIG. 11 is a diagram for explaining another embodiment of the recording method according to the present invention.

Claims (4)

(57) [Claims] 1. A performs a data compression process in accordance with the nature of the pixels constituting the moving image, compressing the number of bits per pixel, the dynamic image data compression, to move a recording position at a predetermined speed When recording a plurality of moving images in an interleaved manner by recording on a recording medium,
Together with the moving picture number or amount of information to leave the recording is recorded in the moving speed of the recording medium to increase, the information for identifying the pre-crisis record position and the moving speed to be recorded on the recording medium method of recording moving image data. Wherein said recording medium is in CD-ROM, the moving speed is a rotation speed, the moving image, according to claim 1, wherein one frame is constituted by the plurality of sectors
Recording method of the dynamic image data. By 3. Information about the previous crisis book position and the transfer <br/> moving speed from a recording medium recorded by the recording method according to claim 1 or claim 2, wherein, identifying the pre-crisis record position together with the identifying the moving speed, while reproduction by rotating the recording medium at the identified movement speed, selectively display the one of the plurality of moving image
The method of reproducing moving image data so as to shown. 4. A data is recorded according to the nature of the pixels forming the moving image.
Data is compressed and the number of bits per pixel is compressed.
Move the recorded moving image data at the recording position at a predetermined speed.
The compressed moving image data is recorded on a recording medium.
A method of manufacturing a recorded recording medium, wherein when interleave recording a plurality of moving images,
If the number of moving images or the amount of information to be recorded increases,
Information is recorded to increase the moving speed of the recording medium and to identify the recording position and the moving speed.
It said recording medium moving image data in so that to record the recording
Method of manufacturing a recorded medium.