JP3070422B2 - Image compression recording medium and image compression recording medium reproducing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image compression recording medium and an image compression recording medium reproducing apparatus, and more particularly to an image compression recording medium on which an image is recorded by an image compression method using an intra-frame coded image (I picture). The present invention relates to an image compression recording medium reproducing apparatus for reproducing a recorded image from an image compression recording medium.

[0002]

2. Description of the Related Art Along with the remarkable progress of the image compression technology, relatively long-time images, particularly moving images recorded on a recording medium such as a compact disk together with sound and character information are becoming widespread. Currently, video CDs are becoming popular as ISO 11172Vi, one of the international standards defined by the MPEG (Moving Picture Experts Group).
The image is compressed according to deo (commonly known as MPEG-1). MPEG-1 employs an image compression and recording method using an I-frame that is an intra-frame encoded image, a P-frame that is an inter-frame encoded image, and a B-frame that is a bidirectional predictive encoded image. Is obtained. A playback device for playing back images and sounds from such a video CD can perform operations such as play, stop, search, and pause, similarly to a normal CD player.

[0003]

In the above-mentioned conventional image compression recording medium and an image compression recording medium reproducing apparatus for reproducing an image or the like from the medium, when performing search or high-speed reproduction,
For example, an intra-frame coded image arranged every 0.5 seconds and an initial image of MPEG image data, I
It is necessary to search for a frame (also referred to as an I-picture) continuously or by skipping a plurality of frames. In the conventional reproducing apparatus, after finding the first I frame, the forward direction (video C)
It is necessary to jump in the outer direction in the case of D) or in the opposite direction (the inner direction in the case of a video CD) by 0.5 seconds or an integral multiple thereof, and search for I frames again in the vicinity, and find I frames one after another. It took some time. For this reason, the waiting time may be long or the reverse search may be reproduced unnaturally. In order to solve such a problem, the address of the I frame may be stored in advance in a memory or the like as an address map so that the required I frame can be accessed at a high speed, and may be read and used. When the method is adopted, an operation for creating an address map is required every time a video CD is exchanged, which not only complicates the operation but also requires a special arrangement for hardware.

Accordingly, the present invention provides an image compression recording medium on which an image is recorded by an image compression method using an intra-frame coded image (I picture) and an image compression recording medium reproducing apparatus for reproducing a recorded image from the image compression recording medium. When performing a search or high-speed reproduction by using an image compression recording medium, it is possible to access desired I frames one after another in a short time, so that the waiting time is short and the reproduction by the reverse search is performed without feeling unnatural. And an image compression recording medium reproducing apparatus.

[0005]

According to the present invention, in order to achieve the above object, a spiral track of a disk-shaped recording medium is provided.
Along with the user's data area of each I frame, the addresses of adjacent I frames in the forward and reverse directions of the I frame and / or the addresses of a plurality of I frames ahead and in the forward and reverse directions of the I frame. It is recorded in advance. Therefore, the image compression recording medium reproducing apparatus according to the present invention is configured to jump the frame to be accessed according to the address of the I frame recorded in the user's data area.

That is, according to the present invention, an image compression and recording system using an I frame which is an intra-frame coded image, a P frame which is an inter-frame coded image, and a B frame which is a bidirectional predictive coded image. Data representing images
The spiral moves from the inner circumference to the outer circumference of the disk-shaped recording medium.
The spa so that the time lapse of the image progresses along the track
Recorded as pits on an ilural track, and
User's area at the beginning of each frame
In the compressed image recording medium, the addresses of adjacent I frames in the forward and backward directions of the I frame and / or a plurality of forward and backward directions of the I frame in each user data area of the I frame. Wherein the address of the I frame is recorded in advance.

Further, according to the present invention, an image compression and recording system using an I frame which is an intra-frame coded image, a P frame which is an inter-frame coded image, and a B frame which is a bidirectional predictive coded image. An image compression recording medium reproducing apparatus for reproducing a recorded image from an image compression recording medium on which an image is recorded, wherein in a search mode, means for searching for an I frame near a currently accessed frame;
Means for reading, from the user's data area of the found I frame, an address of an I frame adjacent to the I frame in the forward or backward direction or an address of a plurality of I frames ahead or in the forward or backward direction of the I frame; Means for decoding the I frame and storing it as one piece of image information; means for reading and outputting image information from the storing means; and jumping to another I frame according to the address of the read I frame Means for reproducing an image compression recording medium.

Further, according to the present invention, an image compression and recording system using an I frame which is an intra-frame coded image, a P frame which is an inter-frame coded image, and a B frame which is a bidirectional predictive coded image. An image compression recording medium reproducing apparatus for reproducing a recorded image from an image compression recording medium on which an image is recorded, wherein in a search mode, means for searching for an I frame near a currently accessed frame;
Means for reading, from the user's data area of the found I frame, an address of an I frame adjacent to the I frame in the forward or backward direction or an address of a plurality of I frames ahead or in the forward or backward direction of the I frame; A first storage unit that decodes the I frame and stores it as one image information; a unit that reads and outputs image information from the first storage unit; and another I / O unit according to the address of the read I frame. Means for jumping to a frame, and second storage means for decoding a plurality of frames subsequent to the I frame and storing as a plurality of pieces of image information until at least the jump to the other I frame is started. Means for reading and outputting image information from the second storage means. Location is provided.

Further, according to the present invention, an image compression and recording system using an I frame which is an intra-frame coded image, a P frame which is an inter-frame coded image, and a B frame which is a bidirectional predictive coded image. In an image compression recording medium reproducing apparatus for reproducing a recorded image from an image compression recording medium on which an image is recorded, a means for searching for an I frame near a currently accessed frame in a forward or reverse search mode; From the user's data area of the I frame, the address of the I frame adjacent to the I frame in the forward or reverse direction or the address of the I frame ahead or in the forward or reverse direction of the I frame in accordance with the search mode is determined. Reading means;
First storage means for decoding a frame and storing it as one piece of image information; means for reading and outputting image information from the first storage means; and transferring to another I frame according to the address of the read I frame. Means for jumping, and only in the case of a forward search, until the jump to the other I-frame is started at least.
A second storage unit for decoding a plurality of frames subsequent to the frame and storing the decoded image information as a plurality of image information; and a unit for reading out and outputting the image information from the second storage unit. An apparatus is provided.

[0010]

The image compression recording medium and the apparatus for reproducing the image compression recording medium according to the present invention have the above-mentioned configuration.
When searching or high-speed reproduction of a recorded image from a recording medium recorded by an image compression method using an I-frame that is an intra-coded image, desired I frames can be accessed one after another in a short period of time. Is short, and the reproduction by the reverse search does not feel unnatural. In the forward search, it is possible to sequentially access only the I frame and reproduce its contents. However, following the reproduction of the I frame, another type of frame (P
(A frame and a B frame) can be sequentially accessed for each of a plurality of frames, and the contents can be reproduced. However, such P
Reproduction of a frame or a B frame is prohibited during a reverse search. This is because in the backward search, the frame reading direction is not normal, so that correct prediction decoding cannot be performed. In addition, if forward playback is incorporated during the backward search, control becomes complicated and the search speed decreases. It is because.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing a relationship between a sector arrangement on one track and a data format in a video CD as an embodiment of an image compression recording medium of the present invention. This video CD is composed of image data (M
PEG video) and audio data (MPEG audio) are recorded, and a synchronization signal (sync), a header, and a subheader are written at the head of each sector.
Next, video or audio data (main data) is written. The lower part in FIG. 1 shows the data format of the MPEG video. The I frame at the left end is an intra-frame coded image (I picture), the next P frame is an inter-frame coded image (P picture), and the next B frame is a bidirectional predictive coded image. (B picture).

The I frames are arranged at a predetermined interval, and a plurality of P frames and B frames are arranged between two consecutive I frames. In addition, the arrangement of the P frame and the B frame can be set as desired at the time of recording. A user data area indicated by hatching in FIG. 1 is provided at the head of the I frame, and MPEG user data is written at the time of recording. The MPEG user's data includes address information in addition to data indicating that the frame is an I frame.
In the example of FIG. 1, the leftmost I frame is I ₀ , and the next I frame in the forward direction (temporally later, that is, from the outer circumference in the case of a video CD).
Let the frame be I ₁ , the next I frame in the reverse direction (time ahead, ie from the inner circumference in a video CD) be I _−1, and similarly in the forward direction I ₂ , I ₃ , I ₄ . . . , The reverse direction is I _-2 , I _-3 , I _-4 . . . When, for example, as the address information of the MPEG User data area of the I-frame I _0, the address indicated in the following table is written.

[0013]

[Table 1]

[0014] As seen from the above table, the address 1, the forward addresses of I ₁ is the next I frame, the address 2, the reverse addresses I _-1 is the next I-frame , the third address, an I frame of the plurality destination forward, for example, an address of the I ₁₀ is the address 4, an I frame in the reverse direction of the plurality destination, for example, an address of the I _-10, respectively Has been recorded. The address at address 1 is for forward search, and the address at address 2 is for reverse search. The address at address 3 is for forward high-speed search, and the address at address 4 is for reverse high-speed search. The search and the high-speed search mentioned here are concepts including high-speed reproduction. As the MPEG user data, 16 bytes are used as the address information, and 4 bytes are used as other information.
About 20 bytes can be used, and about 20 bytes in total.

FIG. 2 is a block diagram of a preferred embodiment of the image compression recording medium reproducing apparatus of the present invention for reproducing images and sounds from the video CD. 2, the CD player unit 1 has a CD decoder / servo control circuit 5, a second CPU 3, an input instruction unit 4, and an indicator 4A, in addition to a disk drive system, an optical pickup and its drive system. The input instruction unit 4 has keys for the user to instruct operations such as play, stop, search, and pause. The signal processing / image reproducing unit 70 is the first CPU 3
0, MPEG decoder 75, video signal processing circuit 76,
NTSC / PAL encoder 78, DRAM 34, RO
M36, crystal oscillators 74, 77 and 79, and SRAM 32 if necessary. Video signal processing circuit 7
Reference numeral 6 includes an interface, a D / A converter, a synchronization signal generator, and the like. The audio signal processing circuit 80 has a digital filter and a D / A converter.

The search in the image compression recording medium reproducing apparatus of the present invention is mainly performed under the control of the first CPU 30. Hereinafter, some search modes will be described with reference to the flowcharts of FIGS. 3 to 5 and the timing chart of FIG. Selection and designation of these search modes are performed by operating the input instruction unit 4 by the user. The second CPU 3 controls according to the selected search mode and sends information of the selected search mode to the first CPU 30. The first CPU 30 executes one of the flows in FIGS. 3 to 5 according to the selected search mode.

The MPEG decoder 75 includes M
An IC for PEG signal processing (for example, 450A manufactured by the company) can be used. This IC includes a decoder and a memory. The MPEG decoder 75 decodes the data of each frame, determines the type of the frame, and
For 0, the information is sent.

(1) Forward Search Mode (I Frame Only) The forward search mode (I frame only) shown in FIG. 3 will be described with reference to FIGS. 6A and 6B. When the forward search mode (I frame only) is started, as shown in FIG. 3, an I frame is first searched, the reproduction data closest to the current address is decoded (step S1), written to the memory, and output. (Step S2). Next, a predetermined outside address in the forward direction is set to jump from the current address to the next I frame (step S3). If the address has not reached the end address (NO in step S4) reproduction is performed (step S5; time t ₁ of the (A) Fig. 6), the picture coding in the pack data following the pack header While checking the type identification code to confirm that the frame is an I frame, a predetermined I frame written in the user's data is detected, read and stored (step S6; same at time t ₁ ), and the I frame image data is read. Decode and store in memory (step S7;
Same at time t ₂ ).

The stored image is output immediately (step S8). Next, the process returns to step S3 to jump to the next I frame. In this case, the next I frame jump is performed in the case of the search at the normal speed, but in the case of the high speed search, for example, the jump is performed to the tenth I frame.
This control is performed depending on whether the address of the user's data shown in Table 1 is set to address 1 or address 3. If the read address has reached the end address (YES in step S4), the routine returns. By such a series of flows, I frames can be accurately taken out at regular intervals,
It can be decoded as a normal image. In FIG. 6B and (D) to be described later, the portion described as “hold” indicates a state in which the image of the I frame read immediately before is displayed as it is. The above-mentioned jump and the following jump are executed when an instruction is sent from the first CPU 30 to the second CPU 3.

(2) Reverse search mode (I frame only) Next, the reverse search mode shown in FIG. 4 will be described with reference to FIGS. 6A and 6D. When the backward search mode is selected, the reproduction data of the nearest I frame not exceeding the current address is decoded while predicting the nearest I frame to the current address (step S1).
1) Write to memory and output it (step S)
12), an inner address which is a return direction is set to jump from the current address to the next I frame (step S13). If not if reached the address to the end address (in the step S14 NO) playback is performed (step S15; time t ₁₁ of FIG. 6 (A)),
The picture coding type identification code in the pack data following the pack header is confirmed to be an I frame. Next detects a predetermined I-frame written to the user's data, and reading stored (step S16; the time t _11), and decodes and stored in the memory (step S17; same, time t _12).

The stored image is output immediately (step S18). Next, the process returns to step S13. If the read address has reached the end address (YES in step S14), the routine returns. By such a series of flows shown in FIG. 4, I frames can be accurately taken out at regular time intervals and decoded as normal images.

(3) Forward search mode (I frame and other several frames following it) The forward search mode shown in FIG. 5 will be described with reference to FIGS. 6A and 6C. . When the forward search mode (I frame and several other frames following it) is started, first, as shown in FIG. 3, an I frame is searched, and the reproduction data nearest to the current address is decoded (step S1). And outputs it (step S2). Next, a predetermined outside address in the forward direction is set to jump from the current address to the next I frame (step S3). If the address has not reached the end address (N in step S4)
O) reproduction is performed; time t ₁ (step S5 in (A Fig 6)), to confirm that an I frame watching the identification code of the picture coding type in the pack data following the pack header while detecting a predetermined I-frame written to the user's data, reading, and stored (step S6; same, time t _1), decodes the I-frame image data is stored in the memory (step S7;
Same at time t ₂ ).

The stored image is output immediately (step S8). Then a predetermined time (for example, 0.2 seconds)
Continue to play a plurality of frames indicated by X in FIG. 6 (A) after (until the time t ₄ in FIG. 6). The frame indicated by X is P
A frame or a B frame, and these frames, that is, several frames other than the I frame, are continuously reproduced. If the address has not reached the end address (NO in step S10), the process returns to step S3. Then, the same flow is repeated. The resulting output is as shown in FIG. By such a series of flows shown in FIG. 5, an I frame and a subsequent frame can be accurately taken out at regular time intervals and decoded as a normal image. In some cases, the final image as shown in (E) of FIG. 6 when the image information to be reproduced by the time t ₄ in FIG. 6 is insufficient is hold. In this case, the jump may be large, but in any case, the flow makes it possible to take out an I-frame at regular time intervals and a subsequent frame.

Although the above embodiment has been described with reference to a case where a video CD is a storage medium, the shape of the storage medium,
The recording method does not matter. Therefore, the present invention is applicable to those using a magnetic tape, a magnetic disk, and other storage media.

[0025]

As described above, according to the image compression recording medium and the image compression recording medium reproducing apparatus of the present invention, the disk
In the user data area of each I-frame along a spiral track of the I- shaped recording medium, addresses of adjacent I-frames in the forward and reverse directions of the I-frame, and / or a plurality of addresses in the forward and reverse directions of the I-frame. The address of the previous I-frame is recorded in advance, and at the time of the search, the image compression recording medium reproducing apparatus jumps the frame to be accessed according to the address of the I-frame recorded in the user's data area. I
The frame can be accessed, so that the waiting time is short and the reproduction by the backward search does not seem unnatural. In the forward search, it is possible to sequentially access only the I frame and reproduce its contents. However, following the reproduction of the I frame, another type of frame (P frame and B frame) following the I frame (Frames) are sequentially accessed for each of a plurality of frames, and the contents thereof are reproduced, whereby a reproduced image with higher quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a relationship between a sector arrangement on one track and a data format in a video CD as an embodiment of an image compression recording medium of the present invention.

FIG. 2 is a block diagram showing an embodiment of an image compression recording medium reproducing apparatus according to the present invention.

FIG. 3 is a flowchart showing an operation of a first CPU in the embodiment of the image compression recording medium reproducing apparatus of the present invention.

FIG. 4 is a flowchart showing an operation of a first CPU in the embodiment of the image compression recording medium reproducing apparatus of the present invention.

FIG. 5 is a flowchart showing an operation of a first CPU in the embodiment of the image compression recording medium reproducing apparatus of the present invention.

FIG. 6 is a timing chart showing an operation of the embodiment of the image compression recording medium reproducing apparatus of the present invention.

[Explanation of symbols]

Reference Signs List 1 player 2 signal processing unit 3 second CPU (constituting jumping means together with player and first CPU) 4 input instructing unit 4A indicator 5 CD decoder / servo circuit 4A indicator 30 first CPU (means for searching I frame together with MPEG decoder, address Means for reading, means for storing,
Output means) 70 signal processing / image reproducing unit 75 MPEG decoder 76 video signal processing circuit 78 NTSC / PAL encoder 80 audio signal processing circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/76-5/956 G11B 20/10-20/12 H04N ^7/ 24-7/68

Claims (4)

(57) [Claims] 1. Data representing an image by an image compression recording method using an I frame that is an intra-frame encoded image, a P frame that is an inter-frame encoded image, and a B frame that is a bidirectional predictive encoded image. Of disk-shaped recording media
Image along spiral track from inner to outer circumference
Time on the spiral track so that the time
At the end of each of the I-frames
In an image compression recording medium in which a user's area is provided at a head portion, the user data area of each of the I frames is
An image compression recording medium in which addresses of adjacent I frames in the forward and reverse directions of a frame and / or addresses of a plurality of I frames in the forward and reverse directions of the I frame are recorded in advance. . 2. An image is recorded by an image compression recording method using an I-frame which is an intra-coded image, a P-frame which is an inter-coded image, and a B-frame which is a bidirectional predictive encoded image. In an image compression recording medium reproducing apparatus for reproducing a recorded image from an image compression recording medium, in a search mode, means for searching for an I frame near a frame currently being accessed, and the I frame from a user data area of the found I frame Means for reading an address of an adjacent I frame in the forward or reverse direction or an address of a plurality of I frames in the forward or reverse direction of the I frame, and decoding the I frame to obtain one image information Means for storing image information; means for reading and outputting image information from the means for storing; According to the address of the I-frame, and means for jumping to another I-frame, image compression recording medium reproducing apparatus characterized by having. 3. An image is recorded by an image compression recording method using an I frame which is an intra-frame encoded image, a P frame which is an inter-frame encoded image, and a B frame which is a bidirectional predictive encoded image. In an image compression recording medium reproducing apparatus for reproducing a recorded image from an image compression recording medium, in a search mode, means for searching for an I frame near a frame currently being accessed, and the I frame from a user data area of the found I frame Means for reading an address of an adjacent I frame in the forward or reverse direction or an address of a plurality of I frames in the forward or reverse direction of the I frame, and decoding the I frame to obtain one image information A first storage unit for storing image information, a unit for reading and outputting image information from the first storage unit, Means for jumping to another I frame in accordance with the address of the issued I frame; and decoding and decoding a plurality of frames following the I frame until at least the jump to the other I frame is started. An image compression recording medium reproducing apparatus, comprising: a second storage unit that stores image information of a sheet; and a unit that reads and outputs image information from the second storage unit. 4. An image is recorded by an image compression recording method using an I frame that is an intra-coded image, a P frame that is an inter-coded image, and a B frame that is a bidirectional predictive encoded image. In an image compression recording medium reproducing apparatus for reproducing a recorded image from an image compression recording medium, in forward or reverse search mode, means for searching for an I frame near a currently accessed frame, and user data of the found I frame Means for reading, from the area, an address of an adjacent I frame in the forward or reverse direction of the I frame or an address of a plurality of I frames ahead or in the forward or reverse direction of the I frame in accordance with the search mode; A first storage unit that decodes the I frame and stores it as one piece of image information; Means for reading and outputting image information; means for jumping to another I frame in accordance with the read address of the I frame; and jumping to the other I frame is started at least only in a forward search. A second storage unit that decodes a plurality of frames subsequent to the I-frame and stores the plurality of image information as a plurality of pieces of image information; and a unit that reads and outputs image information from the second storage unit. An image compression recording medium reproducing apparatus characterized by the above-mentioned.