JP2000032396A - Picture compression recording medium reproducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to reproduce a picture and a voice which do not cause unnaturalness in performing forward twice speed reproduction from a medium by composing a device with a means for reproducing video information from a high speed reading means at a signal speed twice as fast as normal one and a means for thinning data while reproducing voice information at a normal signal speed. SOLUTION: This device is composed of a high speed read-out means for reading a signal by rotating a picture compression recording medium of a disk shape at a rotation speed twice as high as a normal one, a video processing means for reproducing video information from the high speed read-out means at a signal speed twice as fast as the normal one, and a voice processing means for thinning data while reproducing voice information from the high speed read-out means at a normal signal speed. Search in this device is performed mainly by control by a first CPU 30. Selection and specification of search mode is performed by a user operating an input indicating part 4. A second CPU 3 controls according to the selected search mode and, at the same time, transmits information of the selected search mode to a first CPU 30.

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 reproducing apparatus, for example, an image compression recording medium for reproducing a recorded image from an image compression recording medium on which an image is recorded by an image compression method using an intra-frame coded image. It relates to a playback device.

[0002]

2. Description of the Related Art With the rapid progress of the image compression technology as described above, relatively long-time images, particularly moving images, which are recorded on a recording medium such as a compact disk together with audio and text information, are becoming popular. is there. Currently, video CDs that are becoming widespread perform image compression according to ISO 11172 Video (commonly known as MPEG-1), which is one of the international standards defined by MPEG (moving picture coding expert group). 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,
Like a normal CD player, operations such as play, stop, search, and pause can be performed.

[0003]

By the way, in the conventional image compression recording medium reproducing apparatus for reproducing an image or the like from the above-mentioned image compression recording medium, when performing search or high-speed reproduction, for example, at the time of normal reproduction, 0 on the time axis.
Intra-frame coded images arranged every 5 seconds,
It is necessary to search for I frames (also referred to as I pictures), which are initial images of PEG image data, either continuously or by jumping a plurality of frames. To do this in a conventional playback device, after finding the first I-frame, from there it can be either forward (outer direction in the case of a video CD) or backward (video CD).
It is conceivable that an I-frame address is stored in advance in a memory or the like as an address map and read out and used so that an I-frame required in the inner peripheral direction (in the case of (1)) can be accessed at a high speed. However, if such a method is adopted, an operation for creating an address map is required every time a video CD is exchanged, which is not only complicated but also complicated.
You also have to pay for the hardware, such as the need for dedicated memory.

Further, when performing a high-speed search or high-speed reproduction,
It is conceivable to rotate the spindle for driving the disk at high speed, but if the signal processing speed of the circuit part that performs the MPEG data processing is not considered, the video will not be synchronized,
Also, audio is sampled at high speed, making normal reproduction difficult or at least raising the audio pitch.
That is, if the spindle is rotated at twice the normal speed, the frame becomes half the length, the image is disturbed, and the voice pitch is doubled.

In the invention described in claim 1 of the present application, among the above-mentioned problems, in particular, in the case of high-speed reproduction, when the spindle for driving the disk is rotated at high speed,
It is an object of the present invention to provide an image compression recording medium reproducing apparatus capable of reproducing a video signal and an audio signal correctly and reproducing without disturbance or unnaturalness.

[0006]

According to the first aspect of the present invention, in order to solve the above-mentioned problems, a high-speed readout for reading a signal by rotating a disk-shaped image compression recording medium at twice the rotation speed of a normal rotation. Means, video processing means for reproducing video information from the high-speed reading means at twice the normal signal speed, and audio processing means for thinning data while reproducing audio information from the high-speed reading means at a normal signal speed. When,
Is provided.

[0007]

According to one aspect of the image compression recording medium reproducing apparatus of the present invention, not only the I frame but also the P frame and the B frame are reproduced in the double speed reproduction in the forward direction. Reproduction can be performed without pod disturbance.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION
A preferred embodiment will be described with reference to the drawings. The image compression recording medium used in the image compression recording medium reproducing apparatus according to the present embodiment is, for example, a video CD.
An apparatus for reproducing image and audio information from a device will be described. The video CD has image data (MPEG video) and audio data (MPEG audio #) recorded according to MPEG-1, and a synchronizing signal (sync), a header, and a subheader are provided at the beginning of each sector. Is written, and then video or audio data (main data) is written. As an MPEG video data format, an I frame, a P frame and a B frame are arranged in a predetermined pattern as shown in FIG. The I frame is an intra-frame coded image (I picture), the P frame is an inter-frame coded image (P picture), and the B frame is a bidirectional predictive coded image (B picture). is there.

The I frames are arranged at predetermined intervals, 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. In FIG. 1A, the leftmost I frame is represented by I ₀ ,
The forward (after the time, namely video from the outer in CD) to the next I frame of the I _1, the next I frame in the reverse direction (temporally previous, ie the inner circumferential In the video CD) was a I _-1, likewise, the forward direction I _2, I _3,
I ₄ . . . , The reverse direction is I _-2 , I _-3 , I _-4 . . . And

FIG. 2 is a schematic block diagram of an image compression recording medium reproducing apparatus common to each embodiment for reproducing images and sounds from the video CD. In FIG. 1, a CD player unit 1 includes a CD decoder / servo control circuit 5, a second drive unit, an optical pickup, and a drive system therefor.
It has a CPU 3, an input instruction unit 4, and an indicator 4A. The input instructing unit 4 allows the user to play, stop,
It has keys for instructing operations such as search and pause. The signal processing / image reproducing unit 70 includes the first CPU 30, M
PEG decoder 75, video signal processing circuit 76, NTS
C / PAL encoder 78, DRAM 34, ROM3
6. It has crystal oscillators 74, 77 and 79, and further has an SRAM 32 if necessary. The video signal processing circuit 76 has 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 according to this embodiment 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 the operation according to the selected search mode.
Send the information of the selected search mode to 0. 1st CPU
30 executes one of the flows of FIGS. 3 to 5 according to the selected search mode.

The MPEG decoder 75 includes M
An PEG signal processing IC (for example, CL480 manufactured by Kubota C-CUBE) can be used. This IC includes a decoder and a memory. MPEG decoder 75
Decodes the data of each frame, determines the type of the frame, and sends the information to the first CPU 30.

(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. 1A and 1B. When the forward search mode (I frame only) starts, as shown in FIG. 3, first, the reproduction data of the frame (current address) currently being accessed by the optical pickup is decoded (step S1) and written into the memory. And outputs it (step S2). Next, an outer address (jump destination address) in the forward direction is set to jump to a frame at an address advanced by a predetermined address from the current address (step S3). Here, proceeding by a predetermined address corresponds to a time N slightly shorter than the integral multiple of the time interval between adjacent I frames in the reproduction time during normal reproduction. If the time interval of the I frame is 0.5 seconds, N is set to 0.5, 1.0, 1.5, 2.0, and so on. That is, the jump destination address can be obtained by adding the address address corresponding to the time N to the current address. If the jump destination address has not reached the end address (NO in step S4), reproduction is performed (step S5; time t0 in FIG. 1A), and picture coding in the pack data following the pack header is performed.・ Continue playback while watching the type identification code. By this reproduction, the first I frame is detected (step S6; same time t ₁ ), and the I frame image data is decoded and stored in the memory (step S7; same time t).
₂ ).

The stored image is outputted at a timing t3 of a control signal (FIG. 1E) at regular intervals, for example, at intervals of 0.25 seconds (step S8). After waiting for this control signal, the flow returns to step S3, and the same jump as the previous time is performed. In this case, a normal speed search jumps to the position immediately before the next I frame, while a high speed search jumps to every other, every second or third I frame. In this control, the time N to jump in the search mode selected by the user of the image compression recording medium reproducing apparatus is set to 0.5, 1.0, 1.5,
The address is set by selecting from among 2.0. If the read address has reached the end address (YES in step S4), the routine returns. Through such a series of flows, I frames can be accurately taken out at regular time intervals and decoded as normal images. In FIG. 1B, 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 jump and the following jump are performed from the first CPU 30 to the second CPU
The instruction is sent to 3 and executed.

(2) Reverse search mode (I frame only) Next, the reverse search mode shown in FIG. 4 will be described with reference to FIGS. 1A and 1D. When the reverse search mode is selected, first, the reproduced data of the frame (current address) currently being accessed by the optical pickup is decoded (step S11), written into the memory, and output (step S12). From the current address, the number of frames corresponding to the time N slightly shorter than the integral multiple of the time interval between adjacent I frames in the normal reproduction time described in the forward search mode (I frame only) is jumped. To this end, an inner address that is the return direction is set (step S13). If the address has not reached the end address (in the step S14 NO) playback is performed (step S15; time t ₁ 0 in (A) in FIG. 1), the picture coding in the pack data following the pack header・ Continue playback while watching the type identification code. By this reproduction, the first I
Detecting the frame (step S16; the time t _11),
Decode and store in 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. 1A and 1C. . When the forward search mode (I frame and several other frames following it) starts, first, as shown in FIG. 5, the reproduction data of the frame (current address) currently being accessed by the optical pickup is decoded (step S1). The data is written to the memory from S1) and output (step S2). Next, an outer address (jump destination address) in the forward direction is set to jump to a frame at an address advanced by a predetermined address from the current address (step S).
3). If the jump destination address has not reached the end address (NO in step S4), reproduction is performed (step S5; time t0 in FIG. 1A), and picture coding in the pack data following the pack header is performed.・ Continue playback while watching the type identification code. By this reproduction, the first I frame is detected (step S
6; at time t ₁ ), the I-frame image data is decoded and stored in the memory (step S 7; at time t ₂ ).

The stored image is outputted at a timing t3 of a control signal (FIG. 1 (E)) at regular intervals, for example, at intervals of 0.25 seconds (step S8). Thereafter, the reproduction of the frame X (X indicates a P frame or a B frame) shown in FIG. 1A is continued for a predetermined time, for example, 0.2 seconds (step S9; t1 in FIG. 1). If the jump destination address has not reached the end address (NO in step S10), the process returns to step S3, and the same jump as the previous time is performed. The mode of the jump is the same as described above. By such a series of flows in FIG. 5, I frames can be accurately taken out at regular time intervals and decoded as normal images. Note that, in FIG. 1C, a portion described as “hold” indicates a state in which the image of the X frame read immediately before is displayed as it is. That is, a part of the output is held until the timing t5 of the control signal (FIG. 1 (E)) at the constant interval comes. By such a series of flows in FIG. 5, an I frame and a plurality of subsequent P frames or B frames can be accurately taken out at regular time intervals and decoded as a normal image.

Next, a method of selecting a search mode in the image compression recording medium reproducing apparatus according to this embodiment will be described. FIG. 6 shows a part of the operation panel included in the input instruction unit 4 in the block diagram shown in FIG. The operation panel 90 can be provided on the main body of the image compression recording medium reproducing apparatus, or can be provided on a remote control unit.
The reverse search button 9 is displayed on the operation panel 90 from the left side in the figure.
1, a stop button 92, a play button 93, and a forward search button 94 are provided. Note that a pause button may be provided. The second CPU 3 has a function of monitoring the operation states of these buttons. FIG. 7 shows such a second
9 is a flowchart showing a process related to two buttons of a backward search button 91 and a forward search button 94 in the monitoring function of the button operation state of the CPU 3. Steps S21 to S26 are steps for determining whether only one of the corresponding buttons 91 or 93 has been pressed once to three times or more. Steps S27 to S31 are for normal search in the forward or reverse direction according to the determination result. This is a step for setting a double speed search and a triple speed search. In order to realize each of the search modes, the time N to be jumped is set to 0.5, 1.0, or 1.5. In the case of the reverse direction, N is a negative value. The following table shows the relationship between each search mode and the time N to jump. In this embodiment, the maximum speed is 3 times, but the speed can be further increased.

[0020]

[Table 1]

As can be seen from Table 1, for example, when the forward search button 93 is pressed once, the normal forward search mode is set (steps S22 and S28), and the button 93 is pressed once again during execution of this search. Then, the number of operations becomes a total of two times, and the forward double speed search mode is set (steps S24 and S29). If the reverse direction search button 91 is pressed three times in this state, step S24 is executed.
Is NO, and the process proceeds to the step S31 through the step S25.
Is executed. Thus, any of the search buttons 9
It is possible to detect that 1 or 93 has been operated, count the number of operations, and determine the forward or reverse search speed according to the count value.

In the above embodiment, only the I frame or the I frame and other frames (P frame and B frame) following the I frame are reproduced in the search and the high-speed reproduction.
The rotation speed of the disk itself is a normal CLV (constant linear velocity)
The normal rotation speed is such that In the second embodiment described below, the disk is rotated at twice the normal CLV speed in order to reduce the difficulty in reproducing intermittent frames in high-speed reproduction due to the handling of MPEG data. I have. That is, the drive amplifier 2 in the block diagram of FIG. 2 is controlled by the CD decoder / servo control circuit 5, and the number of revolutions of the spindle 10 for rotating and driving the disk is set to twice the normal CLV.

In a conventional image compression recording medium reproducing apparatus, simply rotating the spindle at a high speed may cause no synchronization with the image signal or an unnaturally high pitch of the sound. As the MPEG decoder 75, a circuit having high-speed signal processing capability is employed. By the way, M
The above-mentioned CL480 IC used in the first embodiment as the PEG decoder 75 has a signal processing (transfer) capability of 3 Mbps, that is, a frame reproduction capability. Therefore, when the rotation speed of the spindle 10 is a normal C
When the LV is doubled, each frame to be reproduced has a half of the original time length, but the interval of the vertical synchronizing signal is normally output in the same manner.

FIG. 8 is a timing chart for explaining the operation of the embodiment in another search mode. (A) in FIG. 8 is C
D decoder / servo control circuit 5 to MPEG decoder 7
5 shows a reproduction frame signal given to the reference numeral 5. Also,
(B) is a vertical synchronization signal, and (C) and (D) are MP signals.
The video signal and the audio signal output from the EG decoder 75. In the signal shown in (A), only the hatched portion is latched by the vertical synchronization signal. In other words, the portion between the hatched portion and the next hatched portion is not latched because there is no synchronization signal, so that the data in the portion without hatching is discarded without being reproduced. in this way,
The reproduced frame signal supplied to the MPEG decoder 75 is supplied at a transfer speed twice as fast as when the spindle is rotating at a normal rotation speed, and the time length of each frame is reduced to half of the original time length. , About 1/2 of the data is discarded.

The audio data is also latched by the vertical synchronizing signal (B), similarly to the video data. That is, L
The frequency of RCK (clock of each channel), audio data, and BCK (bit clock) do not change, and are not changed.
Approximately half of the data is discarded as shown in FIG. As described above, the audio signal output from the MPEG decoder 75 has a normal frame length similarly to the video signal, and the pitch of the reproduced audio does not change, and is generated so as to be sufficiently understood as a normal sound.

In this alternative embodiment, in which the rotation speed of the spindle 10 is twice the normal CLV, the forward search mode (I frame only) and the reverse search mode (I When the same mode as that of (frame only) is executed, a high-speed search can be performed as follows. FIG. 9 is a diagram showing the relationship between various modes in this embodiment in relation to buttons on the operation panel. The operation panel here is different from the operation panel shown in FIG. 6, and in addition to the reverse search (RF) button, the stop (STOP) button, the play (PLAY) button, the forward search (FF) button, and the forward scan. Button, reverse scan button,
A pause button is provided. In the figure, (F) shows the forward direction and (B) shows the reverse direction. In FIG. 9, the 5 × speed forward search mode (I) indicated by “5 × speed scan (F)”
The case where (frame only) is executed will be described. First
As in the embodiment, while rotating the spindle at a normal speed, 5
In order to realize the double speed forward search mode (I frame only), in normal playback, if I frames arranged at 0.5 second intervals are jumped every 5 seconds and played, the jump (head kick) and the next Due to the waiting time between jumps, etc., the speed is not actually 5 × speed but about 3 × speed. In FIG. 9, the mode indicated by “3 × speed scan (F)” is of such a mode. On the other hand, in the “5 × scan (F)”, the spindle is rotated at twice the normal rotation speed, and the I frame is jumped and reproduced every 5 seconds. In this case, the reproduction frame signal supplied to the MPEG decoder 75 is supplied at a transfer speed twice as high as the transfer speed when the spindle is at a normal rotation speed, and there is little waiting time during jumping. F) ”, the data at 2.5 intervals is reproduced twice, so that the frequency of the video is doubled, and a more natural motion on the screen is obtained. Although the description has been given of the 5 × speed in the forward search mode (I frame only), the same applies to the reverse search mode (I frame only).

Each frame signal processed by the MPEG decoder 75 is temporarily stored in a DRAM 34 used as a buffer.
However, as described above, the output from the MPEG decoder 75 cannot exceed 30 frames per second, and in this alternative embodiment, about 1/2 of the data is discarded. Are not stored in the DRAM 34 in sequence. Therefore, the decoding is performed at twice the normal speed, similarly to the transfer speed of the reproduced frame signal supplied to the MPEG decoder 75. However, for frames that are not output, DRA
There is no need to store it in M34. Therefore, as a variation of this other embodiment, a flag is generated when the decoding process is completed,
34. By such data erasure, decoding can be performed at a normal speed without performing the decoding speed at twice the normal speed.

Next, an embodiment in the double speed reproduction mode will be described. This embodiment is an embodiment corresponding to the invention described in claim 1 of the present application. Like the above-described embodiment at the time of another search, the rotation speed of the spindle 10 is twice the normal CLV, and each frame to be reproduced is reproduced. Becomes 1/2 of the original time length, and the interval of the vertical synchronizing signal is output at an ordinary interval. However, in the above another search embodiment, only the I frame is sequentially jumped and reproduced, but in this embodiment,
Other frames, that is, B frames and P frames are also reproduced following the I frames. Therefore, high-speed reproduction only in the forward direction is possible. It is to be noted that about half of the video data and the audio data is discarded as in the second embodiment. Further, a flag is generated when the decoding process is completed, and the frame data not to be decoded is stored in the DRAM 3.
As in the above-described embodiment, the data is erased from the data No. 4 and the data can be erased at the normal speed without performing the decoding speed at twice the normal speed.

In another embodiment of the present invention, the search mode can be determined based on the number of times the search button is operated as described in FIG. 7 as a variation of the first embodiment.

Although the above embodiments have been described for the case where the video CD is the storage medium, the first embodiment is an
If it is made using the image compression method according to 1,
The shape of the storage medium and the recording method are not limited. Therefore, the first embodiment is also applicable to those using a magnetic tape, a magnetic disk, or another storage medium. On the other hand, in the embodiment corresponding to claim 1, the spindle needs to rotate at twice the normal rotation speed, and is limited to reproducing data recorded on a rotating disk.

[0031]

As described above, one embodiment of the image compression recording medium reproducing apparatus according to the present invention has the above-described configuration. In particular, in double speed reproduction in the forward direction, not only the I frame but also the P frame and the B frame are used. Can be reproduced at high speed, and in either case, reproduction can be performed in a state where there is no unnaturalness or disturbance in both images and sounds.

[Brief description of the drawings]

FIG. 1 is a timing chart showing an operation in a search mode of an image compression recording medium reproducing apparatus according to an embodiment of the present invention.

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

FIG. 3 is a flowchart illustrating an operation of a first CPU in a search mode of the image compression recording medium reproducing apparatus according to the embodiment of the present invention.

FIG. 4 is a flowchart illustrating an operation of a first CPU in a search mode of the image compression recording medium reproducing apparatus according to the embodiment of the present invention.

FIG. 5 is a flowchart showing an operation of a first CPU in a search mode of the image compression recording medium reproducing device according to the embodiment of the present invention.

FIG. 6 is a plan view showing a part of an operation panel in a variation of the image compression recording medium reproducing device according to the embodiment of the present invention.

FIG. 7 is a flowchart illustrating an operation of a second CPU of the image compression recording medium reproducing apparatus according to the embodiment of the present invention.

FIG. 8 is a timing chart for explaining the operation of another embodiment of the image compression recording medium reproducing apparatus according to the embodiment of the present invention.

FIG. 9 is a diagram showing a relationship between various modes in another embodiment by a relationship with buttons on an operation panel.

[Explanation of symbols]

Reference Signs List 1 player 2 drive amplifier 3 second CPU (constituting jumping means and high-speed reading means together with player and first CPU) 4 input indicator 4A indicator 5 CD decoder / servo circuit 4A indicator 10 spindle 30 first CPU (I frame together with MPEG decoder) Detecting means, address reading means, storing means, outputting means, flag generating means, control means) 34 DRAM (storage means) 70 signal processing / image reproducing section 75 MPEG decoder (video processing means) , Audio processing means) 76 video signal processing circuit 78 NTSC / PAL encoder 80 audio signal processing circuit 90 operation panel (operation means)

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Claims (1)

[Claims] 1. A high-speed reading means for reading a signal by rotating a disk-shaped image compression recording medium at twice the normal rotation speed, and reproducing video information from the high-speed reading means at a double signal speed. An image compression recording medium reproducing apparatus, comprising: a video processing unit that performs audio processing; and an audio processing unit that thins out data while reproducing audio information from the high-speed reading unit at a normal signal speed.