JP3735097B2 - Movie playback apparatus and movie playback method - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a recording medium on which moving image data is recorded and a decoding device for moving image data from the recording medium.
[0002]
[Prior art]
A CD-ROM has a large recording capacity and is used as an external storage medium in a game machine or personal computer using a microcomputer. Image data of a moving image (animation) is recorded on the CD-ROM. It is considered that this image data is read out and supplied to a host computer, and a moving image is displayed on a CRT display.
[0003]
In this case, the conventional method for reading the image data from the CD-ROM is not to read the image data continuously from the CD-ROM and display the moving image on the display, but to record it in a predetermined recording area of the CD-ROM. The moving image data consisting of a plurality of frames is read out and transferred to a large-capacity RAM prepared on the host computer side, and the moving image is displayed by reading out the image data from the RAM.
[0004]
[Problems to be solved by the invention]
However, according to this method, the number of frames per second of the moving image is small, and a smooth motion animation cannot be obtained.
[0005]
Therefore, the inventor of the present invention, as Japanese Patent Application No. 3-74555, reproduces a moving image while continuously reading image data from a CD-ROM, and can realize a smooth motion animation with a large number of frames. Has proposed.
[0006]
By the way, in a game machine or the like, not only image data for animation but also so-called resident characters and other data necessary for the game are required. When animation is performed by continuous reading from a CD-ROM as described above, It is desirable to obtain other data from the CD-ROM without stopping the animation.
[0007]
As a method of satisfying this requirement, a method of using a subcode on a CD signal format can be considered. However, with this method, the amount of data that can be transmitted as data other than animation is limited, and it is difficult to send a large amount of data at a time. The present invention is intended to solve the above problems.
[0008]
[Means for solving the problems]
According to the present invention, the recording medium in which the moving image data including the compressed image data constituting the moving image and the data for processing the image data and the data other than the moving image data are continuously recorded in units of recording areas. A video playback device that plays back video based on video data while sequentially reading data from
Read means for sequentially reading data from the recording medium in units of recording areas;
Storage means for processing the read data;
Read identification information for identifying the data included in the read data,
When the identification information indicates moving image data, the read data is processed using the first area of the storage means in units constituting a screen,
Control means for processing the read data using an area other than the first area of the storage means when the identification information indicates other than moving image data;
There is provided a moving image reproducing apparatus comprising output means for reading out data of a unit constituting a screen processed in the first area of the storage means and outputting the data as a moving image.
[0009]
According to the present invention, moving image data including compressed image data constituting the moving image and data for processing the image data and data other than the moving image data are continuously recorded in units of recording areas. A video playback method for playing back video based on video data while sequentially reading data from a recording medium,
Read data sequentially from the recording medium in units of recording areas,
Determine whether the identification information for identifying the data included in the read data indicates video data,
When the identification information indicates moving image data, the read data is processed in units of screens using the first area of the storage means and reproduced as a moving image,
When the identification information indicates other than moving image data, a moving image reproducing method is provided in which the read data is processed using an area other than the first area of the storage means.
[0010]
[Action]
Data other than the moving image data is inserted and recorded between the moving image data and the moving image data. The moving image data is written in the memory area for reproducing the moving image, and the other data is written in a separate memory area. Therefore, during the period of other data, since the moving image data is lacking, the number of frames is reduced by that amount. Therefore, the moving image (animation) does not stop visually.
[0011]
In this case, a large amount of other data can be inserted at a time from any one of the unit recording areas of the moving image data to any one. Therefore, a large amount of data other than moving image data can be transmitted without stopping the animation.
[0012]
【Example】
First, a data compression method of moving image data and a method of recording compressed moving image data and other data other than moving images on a recording medium will be described.
[0013]
[Data compression method for video image data]
4 and 5 are block diagrams of an example of an encoding apparatus that executes the image data compression method of this example. In this example, the compressed image data is recorded on a CD-ROM. As will be described later, this CD-ROM is used as software for a game machine, and image data is highly compressed so that a moving image can be reproduced.
[0014]
In this example, as shown in FIG. 6A, one frame (one screen) is composed of horizontal × vertical = 256 pixels × 192 pixels, and each pixel represents three primary colors with 5 bits. In practice, one dummy bit is added to the top for convenience of processing, and one pixel is 1 bit (dummy) +5 bits × 3 colors, that is, 16 bits. The original image data is subjected to data compression processing in units of one frame as follows.
[0015]
That is, one frame data of the original image is supplied to the character dividing means 22 through the input terminal 21, and as shown in FIG. 6B, each frame image is a small area block consisting of horizontal × vertical = 8 pixels × 8 pixels. (Hereinafter, this block is referred to as a character). Therefore, as shown in FIG. 6B, an image of one frame is divided into 32 × 24 = 768 characters. The image data C (0) to C (767) of each character is temporarily stored in the register 23.
[0016]
The image data C (0) to C (767) of each character from the register 23 is supplied to the first vector quantization means 24. Also in this example, the vector quantization means 24 processes the image data C (0) to C (767) of each character in parallel. Of course, the image data C (0) to C (767) may be sequentially subjected to vector quantization without parallel processing. The same applies to each processing described later.
[0017]
In this vector quantization means 24, vector quantization is performed for each character image data C (k) (k = 0 to 767) so that the colors represented as pixels in the character are within four colors. Various proposed vector quantization methods can be used. In this example, when a three-dimensional color space is considered with the color components of the three primary colors red, blue, and green orthogonal to each other, each pixel By calculating the distance between the pixels in the color space and collecting the pixels having a short distance from each other, that is, by processing the pixels having similar colors together into one representative color, The pixel data is rounded so that the colors fall within the representative colors of four colors or less.
[0018]
For all characters in one frame, vector quantization is performed so that the colors of the pixels in the character fall within four colors, and then quantization errors in all characters in the one frame (centering on the position of the representative color). , The maximum value Emax of the representative color and each pixel (corresponding to the distance in the color space). At this time, the threshold value Eth allowed as the maximum value of the quantization error in one frame is set in advance. Then, the maximum value Emax of the quantization error is compared with the threshold value Eth. When the maximum value Emax of the quantization error is larger than the threshold value Eth, vector quantization is performed on the image data in each character until just before the quantization error exceeds the maximum value Emax. Reduce the number of colors. This is to make the S / N of image data in all characters in one frame uniform. This is performed until immediately before the maximum value Emax of the quantization error exceeds the threshold value Eth. In this way, the S / N ratio in all frames is kept constant.
[0019]
When quantization is performed in this manner, the number of colors of pixels is reduced in a character with flat color change. This is because the quantization error does not increase so much even if the number of colors decreases in a flat character of color change. In this process, there are also characters in which the number of colors in the character is two, or even one. The color selected in each character is used as the representative color.
[0020]
Thus, the vector quantization means 24 obtains image data compressed to 4 colors or less in each character. The character unit image data from the vector quantization means 24 is supplied to the palette dividing means 25.
[0021]
The palette dividing means 25 classifies the characters into eight groups (each group is called a palette) by collecting the characters having similar colors according to the color distribution in the character. For example, as shown in FIG. 6C, when a group of characters having similar tones according to the content of an image is generated as A, B, C, D, E..., This group A, B, C, A palette is constructed for each of D, E.
[0022]
In this example, the eight palette allocation methods are as follows: (1) The representative color of each character (average value of colors in the character) is calculated, and each character is assumed to be composed of the representative color.
(2) Vector quantization is performed to quantize all characters in one frame into eight colors. That is, since the number of characters is 768, the maximum representative color of the character is 768 colors, which are quantized into 8 color characters.
(3) Characters having the same label (representative color) are combined into one palette.
The three steps are performed.
[0023]
It should be noted that the groups of characters that make up this pallet do not have to be in the continuous character area, but the skipping characters may form a single pallet group.
[0024]
Eight palette data P (0) to P (7) are temporarily stored in the register 26, supplied to the second vector quantization means 27, and processed in parallel.
[0025]
In the second vector quantization means 27, representative colors of 16 pixels are determined for each palette. At this time, if there are more than 16 colors of pixels in one palette, vector quantization is performed in the same manner as in the character, and the colors in the palette are rounded to 16 colors. The resulting 16 colors are used as pixel representative colors.
[0026]
In this way, the image data P (0) to P (7) for each of the eight palettes rounded to 16 colors is supplied to the labeling means 28 and processed in parallel. In each labeling means 28, color conversion tables COL (0) to COL (7) of 16 color data or less than 16 color data selected as the representative colors of the pixels for each palette are created and temporarily stored in the register 29 ( (See FIG. 7). The data of the color conversion tables COL (0) to COL (7) from the register 29 is supplied to the recording processing means 38 as recording data.
[0027]
Each labeling means 28 refers to each color conversion table COL (0) to COL (7), and for each character included in each palette, pixel data rounded to 16 colors is converted into the color conversion of that palette. On the table, the color of the pixel is converted into label image data LAB (0) to LAB (7) expressed by the corresponding color number (see FIG. 8). The label image data LAB (0) to LAB (7) are temporarily stored in the register 30.
[0028]
In this case, as described above, there are characters having four or three colors (FIG. 8A), characters having two colors (FIG. 8B), and characters having only one color (FIG. 8C). When the character has 4 or 3 colors, if there is a table indicating the color numbers of the 4 or 3 colors, each pixel data can be expressed by 2-bit data indicating which of the color number tables. it can. Therefore, each pixel data of a character composed of 4 or 3 colors can be expressed by 2 bits. Similarly, if a character has two colors, it can be represented by a two-color color number table for the character and 1-bit pixel data. Further, if there is only one color, only that color data can be used as will be described later.
[0029]
Characters that can be expressed in 2 bits are hereinafter referred to as 2-bit mode characters, characters that can be expressed in 1 bit are referred to as 1-bit mode characters, and characters of only one color are referred to as single-color characters.
[0030]
In consideration of the decoding process, a 2-bit mode character, a 1-bit mode character, and a single color character can be processed at a high speed by handling them together. However, in 768 characters in one frame, generally, as shown in FIG. 9A, the mode characters are mixed and mixed. In FIG. 9, (1) indicates a 1-bit mode character, (2) indicates a 2-bit mode character, and (circle) indicates a single color character.
[0031]
Therefore, the label image data LAB (0) to LAB (7) of each palette from the register 30 is supplied to the sorting means 31, and as shown in FIG. 9B, the 2-bit mode character, the 1-bit mode character, and the monochromatic character are displayed. One frame of character data is rearranged in order.
[0032]
The sorting means 31 forms a table (hereinafter referred to as a screen table) scr for rearranging characters in one frame into the original order. As shown in FIG. 10, the screen table scr is configured such that when an image of one frame is divided into small areas having the same size as the character, a character number CNo. And a palette number PNo. Are determined for each small area. Is done. The character number CNo. Is the character rank in one frame after sorting the characters to be displayed at the position of the small area. The pallet number PNo. Indicates in which pallet the character displayed in the small area is included in the eight pallets. That is, it indicates which color conversion table is used for decoding. In this case, the character number CNo. And pallet number PNo. Of one small area are composed of, for example, 2-byte data.
[0033]
In the case of this example, 0 to 15 of the character numbers CNo. Are assigned only to the monochromatic characters. That is, in the table scr, when the character displayed at the position of a certain small area is a single color character, the palette number PNo. Is assigned to the small area in the same manner as in the 2-bit mode or 1-bit mode character. Instead of the character number CNo., The color number of the color of the character among the color numbers 0 to 15 of the color conversion table of the palette is assigned. Thereby, the color (single color) of the small area is determined. Therefore, 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.
[0034]
Because of the single color character as described above, the character numbers for characters in the 2-bit mode and the 1-bit mode start from number 16. Originally, 10 bits are assigned to the character number, so there is a sufficient margin for shifting the number.
[0035]
The data of the screen table scr is supplied to the recording processing means 38 as recording data.
[0036]
Of the character unit image data sorted and rearranged by the sorting means 31 as described above, character data C2 (0) to C2 of N pieces (N is an integer of 768 or less) of each 2-bit mode. (N−1) is supplied to the labeling means 33 via the register 32. In the labeling means 33, as shown in FIG. 11A, the character data C2 (0) to C2 (N-1) of each 2-bit mode character, and the color number table of the character's four colors or three colors, Compressed image data dat2 (0) to dat2 (N-1) composed of 2-bit index number data indicating each color number position on the color number table is formed. These compressed image data dat2 (0) to dat2 (N-1) are temporarily stored in the register 34.
[0037]
Similarly, character data C1 (0) to C1 (M-1) of M 1-bit mode characters (M is an integer of 768 or less) are supplied from the sorting means 31 to the labeling means 36 via the register 35. The In this labeling means 36, as shown in FIG. 11B, for each of the character data C1 (0) to C1 (M-1) in the 1-bit mode, a two-color color number table of the character and its color number table Compressed image data dat1 (0) to dat1 (M-1) composed of 1-bit index number data indicating each color number position is formed. These compressed image data dat1 (0) to dat1 (M-1) are temporarily stored in the register 37.
[0038]
All the compressed image data in the 2-bit mode from the register 34 and all the compressed image data in the 1-bit mode from the register 37 are supplied to the recording processing unit 38 as recording data.
[0039]
Further, data such as a resident character and a game condition change are supplied to the recording processing means 38 through the terminal 39.
[0040]
[Generation of Recording Data] The recording processing means 38 creates data to be recorded on the CD-ROM. In this example, this recording data is processed as one block of one frame, but the data recording mode on the CD-ROM is of course according to the data format of the CD-ROM.
[0041]
For example, the sector when the recording mode of the CD-ROM is mode 1 is as shown in FIG. That is, a sync (synchronization) pattern is arranged at the head of the sector, followed by a header including a sector number and a track number. The header is followed by 2 Kbytes of user data, and the last is auxiliary data including user data error detection and error correction codes.
[0042]
In the case of this example, the above-described moving image data and other data are recorded in the user data area of the sector. The first 32 bytes of the 2K user data are used as identification information ID. This identification information ID is information indicating what kind of data is recorded in the user data area and how many sectors the same content data continues. Of course, other information can be included.
[0043]
The contents of the data indicated by the identification information ID include, as will be described later, user data in the sector includes: (1) moving image image data, (2) color conversion table and screen table scr information, (3) Image data of a background still image, (4) resident character data, (5) game condition change data, etc. are prepared.
[0044]
By the way, the above-mentioned data related to the image for one frame is the compressed image data related to the pixel of each character in the 2-bit mode and the 1-bit mode, and the figure for the eight palettes of that frame which is data other than the image data. 7 includes the color conversion tables COL (0) to COL (7) shown in FIG. 7 and the screen table scr shown in FIG.
[0045]
In the case of this example, as shown in FIG. 12, the compressed image data for one frame to be recorded has mode number information indicating the number of characters N in the 2-bit mode and the number of characters M in the 1-bit mode, as shown in FIG. , Compressed image data dat2 (n) (n = 0, 1, 2... N−1) of N 2-bit mode characters and compressed image data dat1 (m) (m) of M 1-bit mode characters = 0,1,2 ... M-1). As described above, the monochrome character is not recorded as pixel data by registering its color information in the screen table scr.
[0046]
As shown on the lower side of FIG. 12, the information for one character includes information of a color number table and index number data for 64 pixels. As shown in FIG. 11, the index number data corresponding to each pixel is 2 bits in the 2-bit mode and 1 bit in the 1-bit mode. In this case, since the number of characters N in the 2-bit mode and the number of characters M in the 1-bit mode change according to the contents of the pixels, the data length of the data related to the character pixels for one frame is variable.
[0047]
In this example, the number of characters in each mode is recorded as mode number information, but instead of this mode number information, between the last character in the 2-bit mode and the first character in the 1-bit mode, Bit pattern mode delimiter information that does not occur as character data may be recorded.
[0048]
In the case of this example, the data amount related to the moving image compressed as described above is as follows per frame.
[0049]
Since there are 8 palettes per frame, the total color conversion table is 16 (colors) × 8 (palettes) × 2 (bytes) = 256 (bytes).
It becomes. Since the screen table scr is 2 bytes per character, 768 × 2 (bytes) = 1536 (bytes)
It becomes.
[0050]
Therefore, the total data amount of the color conversion table and the screen table scr is 2 Kbytes or less and fits in one sector.
[0051]
Further, since the image data of the moving image has 4 types of color numbers expressed in 4 bits in the character of the 2-bit mode, the color number table has 4 (bits) × 4 = 16 (bits) = 2 ( Part-Time Job)
It becomes. Since the index number data is 2 bits, 2 (bits) × 64 = 128 (bits) = 16 (bytes)
It becomes. Therefore, the data amount per character of the 2-bit mode character is 18 bytes.
[0052]
In addition, since the color number of a 1-bit mode character may be two colors, the color number table is 4 (bits) × 2 = 8 (bits) = 1 (bytes)
It becomes. Since the index number data is 1 bit, 1 (bit) × 64 = 64 (bit) = 8 (byte)
It becomes. Therefore, the data amount per character of the 1-bit mode character is 9 bytes.
[0053]
Since each pixel data of a character is not transmitted for a monochromatic character, the compression rate of image data for one frame is determined by the number of 2-bit mode and 1-bit mode characters in one frame and the ratio of the number of monochromatic characters. For example, in the case of 2 bit mode: 1 bit mode: single color = 2: 1: 1 = 384: 192: 192 Character pixel data 2 bit mode 384 × 18 = 6912 bytes 1 bit mode 192 × 9 = 1728 bytes Total 7640 Since it is a byte and is 8 Kbytes or less, it fits within 4 sectors.
[0054]
From the above, in this example, as shown in FIG. 14A, data relating to a moving image can be recorded as 5 sectors for each frame. In other words, 2-bit mode and 1-bit mode character data (mode number information is included in the first sector) is recorded as user data of the first 4 sectors out of 5 sectors. The screen table scr and the color conversion table data are recorded in the fifth sector indicated by hatching in FIG. 14A.
[0055]
As the 32-byte identification information ID of the user data area of each sector, the first four sectors include information indicating that it is moving image data and the number of sectors (the first sector) In this case, 4) is recorded. In the last fifth sector, information indicating the screen table scr and the color conversion table data and the number of sectors (1 in this case) following the information are recorded.
[0056]
In this way, data related to one frame of moving image is repeatedly recorded every five sectors. In this case, the sum of the data for one frame including the screen table scr, the color conversion table, and the image data is 10432 bytes. Therefore, considering that the transmission rate of the CD-ROM is 150 Kbytes / second, In the case of the example, a moving image of 15 frames (frames) / second can be recorded or reproduced.
[0057]
In the case of this example, the resident character and other data input from the terminal 39 are also recorded in the user data area of this sector on the CD-ROM. Furthermore, in the game machine of this example, as will be described later, in the decoder, a background image of a moving image can be separately created as a still image, and a composite image of both can be displayed on a CRT display. ing. For this reason, still image data is also recorded in the CD-ROM. In this case, for example, still image data is recorded by compressing data of 16 bits per pixel into 4 bits. In addition, the resident character is similarly compressed to 4 bits and recorded.
[0058]
These data are inserted and recorded between the data of one frame related to the above-mentioned moving image, as shown by hatching in FIG. 14B. Then, as the first identification ID in the user data area of each sector, the data content and the number of sectors following it are recorded.
[0059]
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. As a program for decoding, a decode program for 2-bit mode and a decode program for 1-bit mode are recorded respectively. A character rearrangement program is also recorded. These program data are recorded separately from the data as described above, and can be read in a batch prior to reproduction of a moving image or the like at the time of decoding. These program data can also be recorded in the middle of the moving image data as data other than the moving image data of the above example.
[0060]
Thus, according to the data compression method described above, the image is hierarchically divided into small areas in units of one frame, and vector quantization is performed on the image data of each layer. You can raise the rate.
[0061]
In this case, a group (palette) is formed by grouping together characters having similar colors, and a plurality of them are formed for one screen, and the image data is divided into palettes (groups). Since the vector quantization process is performed in a palette composed of image parts of similar colors, the quantization error is reduced.
[0062]
Further, since the decoding process can be performed only by referring to the table at the time of decoding, the configuration of the decoder is simplified. Furthermore, 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.
[0063]
In addition, since compression processing is performed without using frame correlation, even if an error occurs during decoding, the error is completed within one frame and does not affect subsequent frames.
[0064]
Furthermore, since the decoder circuit can be provided at low cost and a CD-ROM can be used as a recording medium, it is effective when applied to software for a computer game machine.
[0065]
In the above example, the vector quantization in the vector quantization means 24 is performed so that the S / N in each frame is kept constant so that the quantization error maximum value Emax in the character is maintained in all frames. To be constant. For this reason, the data size after quantization changes according to the information amount of the frame (complexity of the image content).
[0066]
However, by quantizing each character as follows, the data amount (data transmission rate) for each frame can be made constant.
[0067]
That is, first, an initial value of a distance threshold value Eθ for grouping pixels of similar colors in a character is set, and vector quantization is performed for each character based on the threshold value. That is, the vector quantization is performed on the image data in each character until just before the quantization error exceeds Eθ. By this quantization, data compression is performed so that a character having a large color change has four colors. Further, in a character with a flat color change, the number of colors is reduced, and a character having three colors, two colors, or one color is also generated.
[0068]
When the vector quantization process is completed for all characters in one frame, the maximum value Emax of the quantization error in all characters in one frame is calculated. Next, the number N of characters in the 2-bit mode, the number M of characters in the 1-bit mode, and the number L of single-color characters in one frame are counted. Next, the amount of image data per frame is calculated from these numerical values N, M, and L. The calculation of the pixel data amount is as follows.
[0069]
Data amount of one frame = N × 18 (bytes) + M × 9 (bytes) + L × 0 Whether or not the data amount of one frame as a result is equal to or less than a predetermined value, and thus the compression rate becomes a predetermined value. If the data amount is still greater than or equal to the predetermined value, the threshold value Eθ is set to the maximum value Emax of the quantization error, and the above vector quantization process is repeated.
[0070]
As described above, the vector quantization is repeated by changing the threshold value Eθ until the data amount per frame reaches a predetermined data amount. In this case, although the S / N is different for each frame, the transmission data amount is constant. That is, in the case of a moving image to be described later, the number of frames (frames) per second can be made constant.
[0071]
In the above example, the character data having one color is registered in the screen table scr and only the color data is transmitted, and the pixel unit data is not transmitted. Therefore, the traffic on the data transmission path is reduced. be able to.
[0072]
It should be noted that the processing unit when dividing the palette may be divided into three-dimensional palettes as a plurality of frames instead of one frame.
[0073]
[Description of Decoding Device]
Next, a case where an example of an apparatus for decoding image data compressed as described above and recorded on a CD-ROM is applied to a game machine will be described.
[0074]
FIG. 1 shows an example in which the present invention is applied to a game machine using a microcomputer. 1 is the game machine body, 4 is a sub-processing unit, 5 is a CD-ROM, 6 is a program cartridge, and 7 is a sound. This is a data processing unit.
[0075]
The game machine main body 1 is constituted by a microcomputer, 11 is its CPU, 12 is a DMAC (DMA controller), 13 is a RAM for work area, 14 is a PPU (picture processing unit), 15 is Video RAM. The CPU 11, DMAC 12 and RAM 13 are connected to the first system bus 18, the DMAC 12 and PPU 14 are connected to the second system bus 19, and the video RAM 15 and the CRT display 6 are connected to the PPU 14. The second system bus 19 is connected to the sub processor 4 and the audio data main processor 7.
[0076]
In this case, the CPU 11 and the second system bus 19 are connected via the port 16, and the devices connected to the CPU 11 and the second system bus 19 can be accessed via the port 16. .
[0077]
In this example, the video RAM 15 is divided into a plurality of, for example, four memory areas M1 to M4, as shown in FIG. In this example, the memory area M1 is an area for reproducing a moving image, the memory area M2 is an area for a background still image, and the memory area M3 is an area such as a resident character. Each of these memory areas M1 to M3 has a screen area of two frames (two screens), and image data of one of the screen areas is read by the PPU 14 in synchronization with the vertical and horizontal scanning of the CRT display 8. The image is displayed and displayed as an image on the display 8, and while the display is being performed, the image data of the next image to be displayed is written in the other screen area.
[0078]
The memory area M4 is a work area of the PPU 14, and is used as an area for a screen table scr, a color conversion table, and other data.
[0079]
Furthermore, in the main processing unit 7 of the audio data of the game machine body 1, 71 is an APU (audio processing unit), 72 is a D / A converter, 73 is an audio output terminal, and the APU 71 is connected to the bus 19. And connected to the D / A converter 72. When the audio data and its decoding program are loaded into the APU 71, the audio data is decoded into a digital audio signal, and this digital audio signal is D / A converted into an analog audio signal by the converter 72 before being output. 73 is output.
[0080]
The sub-processing unit 4 has a CD player to enable the use of the CD-ROM 5, 41 is the CD player, 42 is a DSP, 43 is a CD-ROM decoder, and 44 is its work area. A RAM 45 is a controller. Audio data and image data are recorded on the CD-ROM 5, and these audio data and image data, particularly image data, are recorded after being compressed as image data by the method described above.
[0081]
The DSP 42 performs error correction on the reproduction signal of the player 41 and separates user data such as image data and control data such as a track number from the reproduction signal. The player 41 is controlled based on the control data and the instruction data from the CPU 11 to reproduce the target data. The decoder 43 is for performing processing such as error correction for the CD-ROM when the reproduction signal of the player 41 is the reproduction signal of the CD-ROM 5.
[0082]
Furthermore, in the sub-processing unit 4, 50 is a DSP, which is a general-purpose DSP, but the sub-processing unit 4 processes image data. The sub processing unit 4 is integrated with the game machine main body 1 in this example, but may be an adapter type with respect to the game machine main body 1. Although not shown, the DSP 50 includes a program RAM and a buffer RAM (which can be configured with one RAM).
[0083]
The program cartridge 6 is used by being inserted into the slot 2 of the game machine body 1 when the game machine is used. When the CD-ROM 5 is not used, the program cartridge 6 is inserted for general game software, and when the CD-ROM 5 is used, a dedicated cartridge is inserted.
[0084]
The cartridge 6 includes a ROM 61 and a RAM 62. In the case of a cartridge for the CD-ROM 5, the game machine main body 1 loads the recorded data of the CD-ROM 5 into the ROM 61 to execute the game. A program for the so-called initialization process is written. The RAM 62 is used, for example, to hold various data relating to the state at that time until the game is resumed when the game is temporarily interrupted, and is backed up by a battery 63.
[0085]
When this cartridge 6 is inserted into the slot 2 of the game machine body 1, the ROM 61 and RAM 62 are connected to the bus 18 through a connector (not shown).
[0086]
Then, the program in the ROM 61 of the cartridge 6 is executed by the CPU 11, and data from the CD-ROM 5 is taken into the RAM 13 of the game machine body 1, and each user data is stored based on the identification information ID in the user data of each sector. Decode processing is performed. As a result, a moving image is displayed, and a background still image and a resident character are displayed without stopping the moving image.
[0087]
That is, when data is reproduced from the CD-ROM 5 by the CD player 41, the reproduced data is supplied in order from the player 41 to the DSP 42 and the decoder 43, and processing such as error correction is performed, and the error correction is performed. Data is DMA-transferred from the decoder 43 to the first buffer area of the RAM 13 by the DMAC 12.
[0088]
Next, the CPU 11 checks the identification information ID of each sector of the data fetched into the RAM 13. Based on this check result, the CPU 11 executes a decoding process procedure corresponding to the reproduction data having the contents indicated by each ID.
[0089]
From the CD-ROM 5, the above-described decoding processing program and game program are loaded into the RAM 13 prior to reproduction of image data or the like.
[0090]
[Decoding processing of video image data]
As a result of checking the identification information ID in the CPU 11, when it is determined that the content of the user data in the sector is moving image data, moving image decoding and display processing is performed as follows.
[0091]
That is, the decoding process is performed on the data of 5 sectors including the compressed image data for one frame as follows. This moving image image data decoding process basically comprises the following three steps.
[0092]
A. For each character, a primary table that converts 2-bit or 1-bit index number data into 4-bit color number data of color conversion tables COL (0) to COL (7) with reference to the color number table. Reference Step B. For each pixel of each pallet character, referring to the color conversion table of that pallet, the color table data decoded in item A is converted into actual color data. Step of rearranging the sorted characters, that is, step of rearranging the pixel data decoded in the item B with reference to the screen table scr to the original character position, and among the steps of the items A to C, A The DSP 50 performs the step of the term, and the PPU 14 performs the steps of the B term and the C term.
[0093]
[1. Step A]
First, the DSP 50 decodes the 4-sector user data including one frame of compressed image data into color number data as follows, and writes the decoded data into the memory area M1 of the video RAM 15. The procedure up to will be described. That is, (1) A program for decoding a character in the 2-bit mode is loaded from the RAM 13 to the DSP 50.
[0094]
(2) Of the character data in the 2-bit mode of the image data DMA-transferred to the first buffer area of the RAM 13, data for 8 characters from the head is DMA-transferred to the DSP 50 by the DMAC 12.
[0095]
(3) In the DSP 50, the step of item A is executed by the program of (1), and the index number data transferred by DMA is converted into color number data (FIG. 11A) by the color number table. By this conversion, index number data (= 18 bytes × 8) for 8 characters is decoded into data with color numbers of 4 bits × 8 pixels × 8 pixels (= 256 bytes).
[0096]
(4) The decoded color number is DMA-transferred by the DMAC 12 to the second buffer area of the RAM 13.
[0097]
(5) Thereafter, the processes (2) to (4) are repeated, and all of the index number data of the characters in the 2-bit mode are decoded into color numbers and DMA-transferred to the second buffer area of the RAM 13.
[0098]
(6) Data of all color numbers in the 2-bit mode DMA-transferred to the second buffer area of the RAM 13 are DMA-transferred by the DMAC 12 to the video RAM 15 via the PPU 14 during the vertical blanking period of the CRT display 8, and the memory It is written in the area M1.
[0099]
(7) When the processes up to (6) are completed, a program for decoding the 1-bit mode character is loaded from the RAM 13 into the DSP 50.
[0100]
(8) Of the character data in the 1-bit mode of the image data DMA-transferred to the first buffer area of the RAM 13, data for 8 characters from the head is DMA-transferred to the DSP 50 by the DMAC 12.
[0101]
(9) In the DSP 50, the step of item A is executed by the program of (7), and the index number data transferred by DMA is converted into color number data (FIG. 11B) by the color number table. By this conversion, index number data (= 9 bytes × 8) for 8 characters is decoded into data of color numbers of 4 bits × 8 pixels × 8 pixels (= 256 bytes).
[0102]
(10) The decoded color number is DMA-transferred by the DMAC 12 to the second buffer area of the RAM 13.
[0103]
(11) Thereafter, the processes of (8) to (10) are repeated, and all the index number data of the 1-bit mode character are decoded into the color number data and DMA-transferred to the second buffer area of the RAM 13 .
[0104]
(12) Data of all color numbers in the 1-bit mode DMA-transferred to the second buffer area of the RAM 13 are DMA-transferred by the DMAC 12 to the video RAM 15 through the PPU 14 during the vertical blanking period of the CRT display 8, and the memory It is written in the area M1.
[0105]
Note that the DMA transfer of the color number of the 2-bit mode in (6) can also be performed immediately before (12) and (11).
[0106]
[2. Steps B and C]
(13) When the processing up to (12) is completed, processing for the fifth sector of one frame of image data starts. That is, the CPU 11 detects that the fifth sector is a sector of data of the screen table scr and the color conversion table based on the identification information ID. Therefore, the CPU 11 DMA-transfers the screen table scr and the color conversion table data DMA-transferred to the first buffer area of the RAM 13 to the video RAM 15 via the PPU 14 by the DMAC 12 without passing through the DSP 50. In this case, the data of the screen table scr and the color conversion table are written in the memory area M4 of the video RAM 15.
[0107]
(14) When the above transfer processing is performed, the PPU 14 executes the steps of the B term and the C term described above in real time. That is, by referring to the color conversion table COL (j), the data of the color number in the memory area M1 processed by (2) to (5) and (8) to (11) is the pixel data of the actual color. By referring to the screen table scr, the pixel data of each character is written at an address corresponding to the original character position.
[0108]
(15) When pixel data for one frame is written in one screen area of the memory area M1 of the video RAM 15 as described above, the display area of the video RAM 15 is switched to the screen area, and the area where the pixel data is written is changed. The screen is activated and the screen is displayed on the display 8.
[0109]
(16) The processing returns to (1), and thereafter the processing of (1) to (16) is repeated for each frame.
[0110]
Thus, the image data reproduced from the CD-ROM 5 is sent to the video RAM 15 one after another while being processed in a pipeline manner between the RAM 13, DSP 50 and PPU 14 as described above. Accordingly, an image based on the image data of the CD-ROM 5 is displayed on the display 8 as a moving image. This moving image display can be performed at a rate of 15 frames / second as described above.
[0111]
[Other data processing]
As described above, the data sector of the screen table scr and the color conversion table is written into the video RAM 15 as a sector other than the moving image by a process different from that of the moving image data sector. Similarly, still image data, resident character data, and other data sectors are also written to the video RAM 13 and other memories by a process different from that of moving images based on the identification information ID.
[0112]
That is, the reproduction data from the CD-ROM 5 is as shown in FIG. 3, and as shown by hatching in the drawing, the other data is stored during one frame (5 sectors) of the moving image data. When a sector is inserted, at the beginning of the inserted other data, the start pointer PS for the processing of the other data is set up, the processing of the other data is started, and the above-described video decoding process is stopped. The moving image remains the previous screen.
[0113]
For other data, the identification information ID of the sector is checked by the CPU 11, the content of the other data and the number of continuous sectors are detected from the identification information ID, and the other data is stored in an appropriate memory area or another data The data is written into the memory, and other processes according to the contents of the data are performed. When the other data sector ends, the end pointer PE is set and the other data processing ends. If the subsequent sector is a moving image sector, the decoding process of moving image data is resumed. Therefore, the moving image continues from the previous screen. In this case, since 5 sectors = 1/15 seconds and the insertion interval of other data is a short period, the moving image appears almost continuous visually.
[0114]
For example, in the case of a still image, other data is processed as follows and written in the memory area M2 of the video RAM 15.
[0115]
(1) First, the CPU 11 checks the identification information ID of user data of a sector to determine that the sector is that of a still image, and the sector that follows the still image is, for example, as shown in FIG. When it is determined that there are 5 sectors, the start sector PS and end pointer PE indicate the interval between the 5 sectors, and the process proceeds from the above-described moving image decoding process to the temporary and still image processing process. Then, the instruction is given from the CPU 11 to the PPU 14.
[0116]
(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 without passing through the DSP 50.
[0117]
(3) The PPU 14 performs a decoding process for returning the still image data from 4 bits to the original 16 bits, and rewrites the decoded still image data in the memory area M2. This data decompression process is executed when a general program cartridge is used as the program cartridge, and the program is prepared for the PPU 14 in advance.
[0118]
The still image decoded as described above is combined with the moving image and used as the background of the moving image.
[0119]
In this way, the CD-ROM records the identification information ID indicating the data content and the number of sectors followed by the same data for each sector. Therefore, the decoding apparatus monitors the identification information ID. Thus, the decoding process for each sector can be performed. Therefore, it is possible to insert and record other data sectors between moving image data in which one frame is composed of a plurality of sectors. A large amount can be inserted into the video data.
[0120]
As for the moving image, if the previous screen is held during the other data period, the moving image continues after the other data period, so that the moving image can be reproduced without stopping visually.
[0121]
Further, according to the example shown in the figure, since the CPU 11 manages the flow of all data, the CPU 11 absorbs the asynchronousness between the reading of the image data of the CD-ROM 5 and the processing of the CPU 11. The image data can be read out continuously. Moreover, the configuration for this is simple as is apparent from FIG.
[0122]
In addition, the DSP 50 performs the first decoding and the PPU 14 performs the second decoding on the compressed image data of the moving image. Therefore, a general-purpose DSP 50 is used. Can reduce costs.
[0123]
Furthermore, since the compressed image data is decoded by the DSP 50 and the PPU 14 separately, the image data can be decoded at a sufficient speed, and a sufficiently moving moving image can be displayed. .
[0124]
In addition, since the DMAC 12 performs data transfer between the RAM 13, the DSP 50, and the PPU 14, it does not become a load on the CPU 11. Further, while the DSP 50 is performing decoding, the CPU 11 is free, so that it is possible to instruct other data processing as described above. As other data, audio data can be inserted. In this case, user data in the sector of the audio data is transferred to the RAM of the APU 71.
[0125]
As a recording medium, not only a disc such as a CD-ROM but also a tape can be used.
[0126]
【The invention's effect】
As described above, according to the present invention, since the identification information ID indicating at least the content of the recording data is recorded on the recording medium for each unit recording area, the decoding apparatus uses this identification information. By monitoring the ID, the decoding process for each unit recording area can be performed. Accordingly, other data can be inserted and recorded between one and a plurality of unit recording areas between moving image data, and a large amount of data other than moving images can be transmitted at a time.
[0127]
As for the moving image, during the period of other data, it is only necessary to hold the previous screen and continue the moving image after the period of other data, so that the moving image is displayed without stopping visually.
[Brief description of the drawings]
FIG. 1 is a block diagram of an embodiment of a decoding device according to the present invention.
FIG. 2 is a diagram for explaining divided storage areas of a memory.
FIG. 3 is a diagram for explaining other data inserted in moving image data.
FIG. 4 is a block diagram of a part of an example of an encoding apparatus that implements an embodiment of a method for compressing image data to be recorded on a recording medium according to the present invention.
FIG. 5 is a block diagram of the remaining portion of an example of an encoding apparatus that implements an embodiment of a method for compressing image data to be recorded on a recording medium according to the present invention.
6 is a diagram for explaining an example of an image data dividing method according to an embodiment of the image data compression method of the examples of FIGS. 4 and 5. FIG.
7 is a diagram for explaining a table used in an embodiment of the image data compression method of the example of FIGS. 4 and 5. FIG.
FIG. 8 is a diagram for explaining an example of compressed data according to an embodiment of the image data compression method of the example of FIGS. 4 and 5;
FIG. 9 is a diagram for explaining an embodiment of the image data compression method of the example of FIGS. 4 and 5;
10 is a diagram for explaining an example of a table used in an embodiment of the image data compression method of the example of FIGS. 4 and 5. FIG.
FIG. 11 is a diagram for explaining an example of recorded compressed image data on a recording medium according to the present invention.
FIG. 12 is a diagram showing an example of a format of data recorded on a recording medium according to the present invention.
FIG. 13 is a diagram for explaining a sector format of CD and identification information ID for each sector recorded on the recording medium according to the present invention.
FIG. 14 is a diagram showing an example of reproduction data from an example of a recording medium according to the present invention. .
[Explanation of symbols]
1 Game console
5 CD-ROM
6 Program cartridge
8 CRT display
11 CPU
12 DMA controller
13 RAM
14 PPU (Picture Processing Unit)
15 Video RAM
22 Character division means
24. First stage vector quantization means
25 Pallet dividing means
27 Second-stage vector quantization means
38 Recording processing means
39 Other data input terminals
41 CD-ROM player
50 General-purpose DSP

Claims (9)

Data is sequentially read from a recording medium in which moving image data including compressed image data constituting the moving image and data for decoding the image data and data other than the moving image data are continuously recorded in units of recording areas. However, a video playback device that plays back video based on video data,
Read means for sequentially reading data from the recording medium in units of recording areas;
Storage means for processing the read data;
Read identification information for identifying the data included in the read data,
When the identification information indicates moving image data, the read data is decoded using the first area of the storage means in units constituting a screen,
Control means for processing the read data based on the identification information using an area other than the first area of the storage means when the identification information indicates other than moving image data;
An apparatus for reproducing a moving picture, comprising: output means for reading out data of a unit constituting a screen decoded in the first area of the storage means and outputting the data as a moving picture.   The video playback device according to claim 1,
  The moving image reproducing apparatus characterized in that the control means interrupts the decoding process for the data whose identification information indicates moving image data while the data indicating the identification information indicates other than moving image data.   The video playback device according to claim 2,
  The output means holds the output state of the data of the unit constituting the screen output immediately before the control means interrupts the decoding process for the data whose identification information indicates moving image data. A video playback device.   The video playback device according to claim 1,
  When the identification information indicates a still image, the control unit synthesizes an image based on the data with unit data constituting a screen decoded in the first area of the storage unit. A video playback apparatus characterized by the above.   It is a moving image reproducing device according to any one of claims 1 to 4,
  The moving image reproducing apparatus according to claim 1, wherein the first area of the storage means is configured on a video RAM.   It is the moving image reproducing device according to any one of claims 1 to 5,
  The moving picture reproducing apparatus, wherein the recording medium is a CD-ROM.   Data is sequentially read from a recording medium in which moving image data including compressed image data constituting the moving image and data for decoding the image data and data other than the moving image data are continuously recorded in units of recording areas. However, a video playback method for playing a video based on video data,
  Read data sequentially from the recording medium in units of recording areas,
  Determine whether the identification information for identifying the data included in the read data indicates video data,
  When the identification information indicates moving image data, the read data is decoded using the first area of the storage means in units constituting the screen, and reproduced as a moving image,
  When the identification information indicates other than moving image data, the read data is processed based on the identification information using an area other than the first area of the storage means. Method.   The moving image playback method according to claim 7,
  A moving image reproducing method characterized in that decoding processing for data whose identification information indicates moving image data is interrupted while data indicating identification data other than moving image data is processed.   Movie playback method for playing a movie based on movie data while continuously reading movie data including compressed image data constituting the movie and data for decoding the image data and data other than the movie data Because
  The data divided into units is read sequentially through the medium,
  Determine whether the identification information for identifying the data included in the read data indicates video data,
  When the identification information indicates moving image data, the read data is decoded using the first area of the storage means in units constituting the screen, and reproduced as a moving image,
  When the identification information indicates other than moving image data, the read data is processed based on the identification information using an area other than the first area of the storage means. Method.

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