JPH08242426A - Disc playback device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a disk reproducing device which is excellent in performance and advantageous in cost without performing complicated memory control even when performing special reproduction. [Structure] During special reproduction, the read start address of the disk medium 21 is increased / decreased every several fields according to the special reproduction mode, and the write operation of the image output memory means 26 is performed in synchronization with the read timing of the buffer memory means 23. By carrying out intermittently, the control of the buffer memory means 23 can be kept the same as the control during the normal reproduction even during the special reproduction such as the slow reproduction, and the special reproduction can be performed without performing the complicated address control. The image can be easily obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention simplifies buffer memory control when special reproduction such as forward / reverse slow play or forward / reverse skip play is performed on image data compressed and recorded on a disk medium. Disc playback apparatus capable of playing

[0002]

2. Description of the Related Art Conventionally, in the field of tapeless non-linear editing equipment and the like, due to its high accessibility, a disk recording / reproducing apparatus for handling information such as digital moving images and digital audio using a hard disk as a recording medium. The applied device is drawing attention.

In devices handling such disk media, a bus interface such as SCSI or PC / AT is adopted as a hard interface for data input / output between the disk drive device and an external controller.

Therefore, a control command for the rotation state of the disk medium and reading / writing of data on the disk medium are performed.
Designation of a write (hereinafter referred to as R / W) address and actual communication of R / W data are all performed via this bus interface.

By the way, the specified addressing is
It does not complete in an instant, and there is an average wait time (time until the target data moves to the position of the head) that depends on the disk rotation speed, and seek time until the head moves to the desired track. To do. Therefore, in order to record and reproduce a moving image in real time, it is necessary to transfer data while absorbing the time required for controlling the rotation state, the seek time, and the like. In order to absorb this time, it is necessary to compress the image and gain a time margin.

FIG. 7 shows the timing of the image input data and the bus data when the image input data is compressed and recorded on the disk medium via the bus interface. Figure 7 (a) is the image input data before compression, Figure 7 (b)
Is the compressed bus data transferred to the disk medium. Further, FIG. 8 shows the timing of the bus data and the image output data when the image data compressed and recorded on the disk medium is read out through the bus interface and expanded and reproduced. FIG. 8A shows compressed bus data transferred from the disk medium, and FIG. 8B shows output image data after decompression. 7 and 8 show, as an example, a case where data is transferred in units of 8 fields.

Generally, since the data transfer timing on the disk medium side is different from the transferable timing by the compression / expansion means, a buffer memory for timing and transfer rate conversion is required.

FIG. 9 shows an example of a disk recording / reproducing apparatus for performing compression recording and expansion reproduction.

At the time of recording, a video signal is input to the input terminal 1 and stored in the image input memory 2. The image input memory 2 includes an A / D converter, converts an input video signal into a digital signal and stores it. The digital video signal from the image input memory 2 is compressed by the compression processing unit 3 and then supplied to the buffer memory 4, where the data transfer rate is converted and stored in the disk medium 7 via the bus interface 5. In the bus interface 5,
At the time of recording / reproducing, the disc address is designated by the disc address control unit 6.

At the time of reproduction, the image compression data is read from the disk medium 7 through the bus interface 5 and temporarily stored in the buffer memory 8, where the data transfer rate is converted and expanded by the expansion processing unit 9. After that, it is stored in the image output memory 10. The image output memory 10 includes a D / A converter, stores the decompressed data, converts the decompressed data into an analog signal, and outputs the analog signal from the output terminal 11. The reason why the image input memory 2 and the image output memory 10 are required is to absorb the difference in the data transfer timing between the compression processing unit 3 and the expansion processing unit 9. Of course,
The image input memory 2 and the image output memory 10 may be combined.

Now, here, the compressed image data is
Consider the case where data is recorded sequentially on the disk medium. A hard disk will be described as an example of the disk medium.

FIG. 10 shows a conceptual diagram of a recording format on the hard disk. Tracks are formed in a ring shape from the outermost circumference on the hard disk toward the center, and the track numbers are assigned so that the numbers increase from the outermost circumference toward the center. Fields of odd number (ODD) and even number (EVEN) of the compressed video signal are sequentially recorded with a track length required in order. ODD1 and EVEN1 are the first and second odd and even fields,
ODD2 and EVEN2 are each the second of the odd and even fields
Refers to the second field. ODD2 (1) and ODD2 (2) are divided into two, the outermost track and the next inner track, because the second odd field ODD2 is insufficient for the recording area on one track only. It is indicated that it is recorded.

In the case of normal reproduction of the disk medium recorded in this way, it is sufficient to perform sequential addressing just as at the time of recording.

During reproduction, the data read from the disk medium 7 as shown in FIG.
And the access rate of the decompression processing unit 9 (that is,
It is read from the buffer memory 8 according to the decoding rate).

FIG. 11 shows the buffer memory 8 during normal reproduction.
An example of the contents of FIG. 11 shows a case where compressed image data is written to and read from the disk medium 7 in units of 8 fields in the buffer memory 8 during reproduction. 1 from disk media 7 to buffer memory 8
If the transfer unit of times is called a packet, 1 packet = 8 fields in the example of FIG. During normal playback,
From the reset state, fields 1 to 1 as packet 1
Field 8 is written and read, fields 9 to 16 are written and read as packet 2, and fields 17 to 24 are written and read as packet 3. The same applies to packet 4 and thereafter. In this example, one packet has eight fields, but one packet is not limited to eight fields.

The reason why several fields are collectively made into a packet and read from the disk medium for each packet in this way is to increase the sequential addressing period and absorb the seek time and the overhead time such as command communication.

Next, as an example of special reproduction, normal rotation slow reproduction and reverse rotation slow reproduction will be described. Here, the normal rotation and the reverse rotation do not mean the rotation direction of the disk medium 7 itself, but whether the motion of the reproduced image is positive or negative in the time axis direction. To do. Normal reproduction is normal rotation.

Also during the normal slow reproduction, as described above, writing is performed in the buffer memory 8 in units of packets, and after writing, new writing is not performed until all 8 fields have been read. That is, writing to the buffer memory 8 is performed intermittently in time. The timing of reading from the buffer memory 8 changes according to the slow speed, and if it is, for example, 1/4 slow, the contents of the field 1 are 1 → 1 → 1 → 1 and 4
The data in field 2 is read 2 times
It is read 4 times in succession from 2 → 2 → 2. In the same manner, the fields 3, 3, 4, ... Are successively read four times for each field.

FIG. 12 is a diagram showing an operation sequence during 1/8 normal slow motion reproduction. FIG. 12 (a) shows the contents of the buffer memory 8 at the time of normal slow reproduction, and the contents of the buffer memory 8 at the time of normal reproduction are written to the buffer memory 8 only once per packet 1-8. Is. Then, the reading from the buffer memory 8 is 1/8 slow as shown in FIG.
In the real time of 8 = 64 fields, the contents of each field are continuously read eight times, expanded by the expansion processor 9, and continuously expanded as they are in the image output memory 10 as shown in FIG. 12 (c). Will be written. Image data is output from the image output memory 10 to a display device (not shown) at the timing shown in FIG. Since reading is performed from the image output memory 10 on a field-by-field basis, the reading shown in FIG. 12D is performed at a timing delayed by one field with respect to the writing timing shown in FIG. 12C.

In this way, for example, in the 1/8 forward slow reproduction, the write address control (that is, disk address control) to the buffer memory 8 is intermittently performed in time, and the read address of the buffer memory 8 is also controlled. Control is also different from that during normal reproduction, and address control for reading the same address eight times is performed.

Next, the reverse slow reproduction will be described.

Here, it is assumed that the fields 9 to 16 are totally 8 in total.
It is assumed that the field data is transferred from the disk medium 7 and written in the buffer memory 8. During reverse slow reproduction, the read start address of the buffer memory 8 is decremented for each field, for example, the field 1
The access address of the buffer memory 8 is controlled such that the field 15 is read 8 times after reading 6 6 times.

FIG. 13 is a diagram showing an operation sequence during 1/8 reverse slow reproduction. FIG. 13 (a) shows the contents of the buffer memory 8 at the time of reverse slow reproduction, and the contents of the buffer memory 8 at the time of normal reproduction need only be written to the buffer memory 8 once for each packet 1-8. is there. Then, since the reading from the buffer memory 8 is 1/8 slow, as shown in FIG.
In the real time of 8 = 64 fields, the contents of each field are continuously read eight times, expanded by the expansion processor 9, and continuously expanded as they are in the image output memory 10 as shown in FIG. 13 (c). Will be written. Image data is output from the image output memory 10 to a display device (not shown) at the timing shown in FIG. 13 (d). Since the image output memory 10 reads out in units of fields, in this case also, the reading of FIG. 13 (d) is performed at a timing delayed by one field with respect to the writing timing of FIG. 13 (c). .

In this way, the fields 16 to 9 are read from the buffer memory 8 eight times for each field,
Disk media 7 if field 9 is read 8 times
Performs a new address seek, the data of fields 1 to 8 is transferred to the buffer memory 8 as the next packet, and the data written in the buffer memory 8 is read from the field 8 in the same sequence.

In this case as well, the data read from the buffer memory 8 and decompressed is continuously written to the image output memory 10 as it is, which is the same as in the normal slow reproduction. The address must be incremented during reading of the field data while decrementing the read start address for each field.

The control of each circuit block at the time of special reproduction in the above-mentioned conventional disk recording / reproducing apparatus is summarized as follows.
As shown in FIG. Regarding the write operation from the disk medium 7 to the buffer memory 8, an intermittent write operation (W) is performed corresponding to the access address based on the disk address control of the disk medium 7, and a read operation from the buffer memory 8 is performed. As for (R), it is necessary to finely control the memory read address according to the special reproduction mode, which requires complicated address control. For example, in the slow reproduction, unlike the normal reproduction, it has been necessary to perform control to repeat the same read address a predetermined number of times (for example, 8 times). Therefore, as the buffer memory 8, it is necessary to use a RAM capable of address control, for example, a dual port type DRAM (dynamic RAM), which results in high cost and slow speed, and also for address control. There is a problem that the configuration of the external control circuit is complicated. Regarding the write (W) and read (R) operations of the image output memory 10, the same constant R / W control as in normal reproduction may be performed even in the special reproduction mode.

[0027]

As described above, in the conventional disc recording / reproducing apparatus, when special reproduction such as slow reproduction is performed, the address controllable RAM is required as the data transfer buffer memory, and the cost is reduced. There has been a problem that the speed becomes slow, the speed becomes slow, and the address control circuit becomes complicated.

Therefore, in view of the above problems, the present invention provides a disc reproducing apparatus which is advantageous in terms of speed and cost, without complicated memory control even when performing special reproduction. It is intended.

[0029]

According to a first aspect of the present invention, there is provided a disk reproducing apparatus in which a disk medium in which digital image data is compressed and recorded and data compressed and recorded in the disk medium are stored in a predetermined number of field images. A read address control means for performing read control in packet transfer units, and for regularly increasing or decreasing the read start address of the disk medium for each packet in a unit of a predetermined number of fields or a number of frames according to the special reproduction mode; From the buffer memory means, buffer memory means for writing the compressed image data transferred from the medium in packet units, rate conversion and outputting to the next stage, buffer memory control means for controlling writing and reading of this buffer memory means, Decompress the read compressed image data Image decompressing means for writing and reading the image data decompressed by the compressing and decompressing means in units of fields or frames, and the image output memory means for synchronizing with the read timing of the buffer memory means. And an image output memory control means for intermittently performing the write enable operation.

According to a second aspect of the present invention, the buffer memory means in the disc reproducing apparatus according to the first aspect is F
It is an IFO memory.

According to a third aspect of the present invention, when the read address control means in the disc reproducing apparatus according to the first or second aspect specifies the normal slow reproduction mode as the special reproduction mode, the disc for each packet is recorded. It is characterized in that the read start address of the medium is increased in units of one field or one frame.

According to a fourth aspect of the invention, when the read address control means in the disc reproducing apparatus according to the first or second aspect specifies the reverse slow reproduction mode as the special reproduction mode, the disc medium for each packet. It is characterized in that the read start address of is reduced in units of one field or one frame.

According to a fifth aspect of the invention, when the normal address skip reproduction mode is designated as the special reproduction mode by the read address control means in the disk reproduction apparatus according to the first or second aspect, the disk for each packet is discriminated. It is characterized in that the read start address of the medium is increased in units of a predetermined number of fields or frames according to the skip interval.

According to a sixth aspect of the present invention, when the read address control means in the disc reproducing apparatus according to the first or second aspect specifies the reverse skip reproducing mode as the special reproducing mode, the disc medium for each packet. The read start address of is reduced by a predetermined number of fields or frames in accordance with the skip interval.

According to a seventh aspect of the present invention, the buffer memory control means in the disk reproducing apparatus according to any one of the first to fourth aspects is configured as a special reproduction mode which is a normal slow motion reproduction mode or a reverse slow motion reproduction mode. When specified, the same packet content is controlled to be read n times (n is an integer) from the state in which the packet data is written in the buffer memory means.

According to an eighth aspect of the present invention, the read address control means in the disc reproducing apparatus according to the first aspect temporarily sets the amount of compressed 1-field image data written in the disc medium to S [LBU]. If the number of access fields in a packet is F [field], the start address (unit is LBU) of the packet currently being reproduced is A [NOW], and the start address to be accessed in the next packet is A [NEXT]. A [NEXT] = A [NOW] ± F × S × N is controlled so that the relational expression is satisfied. Here, “+” is the normal direction reproduction and “−” is the reverse direction reproduction. Applied, N is a value that changes in each playback mode, N = 0
Still playback when is N, slow playback when N = 1 / (F × n) [n is an integer], normal playback when N = 1 [However, only “+” in the above formula], skipping when N = 2 It is characterized by being reproduction.

[0037]

According to the first aspect of the invention, when the trick play is performed, the read address control means increases or decreases the read start address of the disk medium for every several fields according to the trick play mode, and the buffer memory means operates. By intermittently performing the write operation of the image output memory means in synchronism with the read timing, it is not necessary to perform complicated address control for the buffer memory means even during special reproduction, and the same control as in normal reproduction is performed. The special reproduction image can be easily obtained. Therefore, the structure of the buffer memory control unit can be simplified, and as the buffer memory unit, it is not necessary to use an expensive memory such as a DRAM capable of address control, and the cost of the disk device can be reduced. . As described in claim 2, a low-cost FIFO memory, for example, can be used as the buffer memory means.

According to the third and fourth aspects of the present invention, the normal slow reproduction and the reverse slow reproduction are possible.

According to the fifth and sixth aspects of the present invention, it is possible to perform forward rotation skip reproduction and reverse rotation skip reproduction.

According to the seventh aspect of the invention, it is possible to control the slow speed by changing the numerical value of n during the forward slow reproduction and the reverse slow reproduction.

According to the invention of claim 8, the relational expression N
By specifying the value of, the reproduction mode can be specified and the start address of the packet to be read next from the disk medium in the reproduction mode can be easily set.

[0042]

EXAMPLES Examples will be described with reference to the drawings. FIG. 1 is a block diagram showing a disc reproducing apparatus according to an embodiment of the present invention.

In FIG. 1, the disk medium 21 stores compressed image data. Here, it is assumed that this image data is moving image data. At the time of reproduction, the compressed image data stored in the disk medium 21 is read out from the disk medium 21 as a single packet for a predetermined number of fields (for example, 8 fields) using the read address from the read address control means 22. And is stored in the buffer memory 23 via a bus interface (not shown) such as SCSI. The buffer memory 23 may have a capacity of at least one packet. The read address control means 22 includes
From the mode input terminal 28, normal playback, normal slow playback,
A mode signal corresponding to a reproduction mode such as reverse slow reproduction, forward skip reproduction, or reverse skip reproduction is supplied. The forward skip reproduction is high-speed reproduction by skipping frames in the forward direction, and the reverse skip reproduction is high-speed reproduction by skipping frames in the reverse direction. Further, as the buffer memory means 23, for example, a FIFO (First In First Out) memory is used. The buffer memory control means 24 controls the writing and reading of the buffer memory means 23, and the data transfer rate is converted and supplied to the image decompression means 25. The data expanded by the image expansion means 25 is stored in the image output memory means 26. Image output memory means 2
6, the writing and reading are controlled by the output control means 27. The output control means 27, like the read address control means 22, receives from the mode input terminal 28,
A mode signal corresponding to a reproduction mode such as normal reproduction, forward slow reproduction, reverse slow reproduction, forward skip reproduction, or reverse skip reproduction is supplied. The control of the buffer memory control means 24 and the control of the output memory control means 27 are executed at timing. The image output memory means 26 includes a D / A converter, stores the expanded data, converts the expanded data into an analog signal, and outputs the analog signal from the output terminal 29.

A unit of data transfer (packet) from the disk medium 21 to the buffer memory means 23 is, for example, 8 fields. By transferring in packets in this way, the overhead time related to communication can be reduced, and the margin time that can be created by this is the time for specifying the next disk access address and the actual head seek time after transferring one packet of data. Can be applied to.

The number of fields in one packet depends on the image compression rate and the transfer rate of the disk medium, but if it is too small, it will increase the overhead time involved in communication, and if it is too large, the overhead time will decrease.
Since it becomes necessary to increase the capacity of the buffer memory means 23, it is necessary to select an appropriate value.

Next, the operation of FIG. 1 will be described with reference to FIG.

FIG. 2 is a diagram for explaining the control state of each circuit block in FIG. 1 during special reproduction.

During special reproduction, the read start address of the disk medium 21 is controlled by the read address control means 22 to increase / decrease every several fields according to the special reproduction mode, and the output memory control means 27 is used. The writing operation of the image output memory means 26 is controlled to be intermittently performed in synchronization with the read timing of the buffer memory means 23. As a result, the control of the buffer memory means 23 may be kept at the same control as during normal reproduction even during special reproduction such as slow reproduction, and the special reproduction image can be easily displayed without performing complicated address control. It becomes possible to obtain. Also, the buffer memory means 23
Since the address control of is always constant regardless of the trick play mode, a low cost and high speed FIFO memory can be used.

First, the case where a normal reproduction mode signal is input as the mode input will be described. During normal reproduction, the contents of the buffer memory means 23 are sequentially rewritten as shown in FIG. That is, in the writing period, the write reset is only applied in units of 8 fields. On the other hand, the buffer memory means 23
In order to prevent data read / write outpacing, read reset is applied in synchronism with writing, and in succession to each field in synchronization with the expansion processing timing of the image expansion means 25. The data is read. The decompressed field data is written in the image output memory means 26 and then read out, added with a synchronizing signal and the like, and output from the output terminal 29 to a display device as a display device. At this time, it goes without saying that reading / writing from / to the image output memory means 26 is always continuously performed.

Next, the case where a normal slow-motion reproduction mode signal is input as the mode input will be described.
FIG. 3 shows an operation sequence at the time of normal slow reproduction, in which the disk access contents in each packet unit, the sequence in which the disk access contents are written in the buffer memory means 23, and then the image is output from the image output memory means 26. Is shown.

FIG. 3 (a) shows the contents of the buffer memory means 23 at the time of normal slow reproduction, and unlike the buffer memory contents at the time of normal reproduction, the writing from the disk medium 21 to the buffer memory means 23 is a packet. 1, 2,
3, the read start address from the disk medium 21 is set to 1 for each packet.
Increase by the field. This disk read control is performed by the read address control means 22.
Therefore, as shown in FIG. 3A, the fields 1 to 8 are read from the disk medium 21 as the packet 1 and written in the buffer memory means 23, and then the fields 2 to 9 are read as the packet 2 from the disk medium 21. It is output and written in the buffer memory means 23. Next, the fields 3 to 10 are read out from the disk medium 21 as the packet 3 and written in the buffer memory means 23. The same applies to packets 4 and later.

Then, the reading from the buffer memory means 23 is performed in the same manner as in the normal reproduction, as shown in FIG. 3 (b). Therefore, the fields 1 to 8, 2 to 9, 3 to 10, ... Are sequentially read from the buffer memory means 23. In this way, first, the buffer memory means 23
, Fields 1 to 8 are continuously written and read, and are output as they are through the image expansion means 25.
For example, according to the read timing of field 8,
As shown in FIG. 3C, the decompressed data is written to the image output memory means 26 only once (one field). That is, the writing to the image output memory means 26 is performed by intermittently writing the field data continuously read from the buffer memory means 23. Here, the output memory control means 27 controls the field 8, which is the final field of each packet,
Field 9, field 10, ... Are sequentially written in the image output memory means 26 in an intermittent manner. Then, since the reading from the image output memory means 26 is carried out continuously as shown in FIG. 3 (d), the contents of the field 8 are read continuously 8 times, then The content of the field 9 is read eight times in succession, and then the content of the field 10 is read eight times in succession, ...
A slow playback image is output like this. The normal slow motion reproduction can be performed by the above operation sequence.

In this embodiment, the last field of each packet is written in the image output memory means 26, but the present invention does not limit which field is fetched. Of course.

In the present embodiment, although the 1/8 normal slow motion reproduction is performed, the same packet contents are reproduced by the control of the buffer memory control means 24 from the write state of the buffer memory means 23 of FIG. When the control is performed so that the image output memory 26 is read once (n is an integer) and the writing to the image output memory 26 is intermittently written and continuously read as in the above example, 1 / (8 × n) is thrown. Speed control is possible. Similarly, if the number of fields in one packet is 4, it goes without saying that slow speed control at 1 / (4 × n) is possible.

Next, a case where a mode signal for reverse slow reproduction is input as the mode input will be described.
FIG. 4 shows an operation sequence at the time of reverse slow-motion reproduction. It shows the disk access contents in units of packets and the sequence in which the image is output from the image output memory means 26 after being written in the buffer memory means 23. Shows.

FIG. 4 (a) shows the contents of the buffer memory means 23 at the time of reverse slow reproduction, and unlike the buffer memory contents at the time of normal reproduction, the writing from the disk medium 21 to the buffer memory means 23 is packet 1 , 2,
3, the read start address from the disk medium 21 is set to 1 for each packet.
Decrease by the field. This read control of the disk medium is performed by the read address control means 22. Therefore, if the fields 3 to 10 are read from the disk medium 21 as the packet 1 and written into the buffer memory means 23 as shown in FIG. 4A, then the packet 2 from the disk medium 21 to the fields 2 to 9 is written. Is read out and the buffer memory means 23
Is written to. Next, fields 1 to 8 are read from the disk medium 21 as a packet 3 and written in the buffer memory means 23. The same applies to packets 4 and later.

Then, the reading from the buffer memory means 23 is performed in the same manner as in the normal reproduction, as shown in FIG. 4 (b). Therefore, the fields 3 to 10, 2 to 9, 1 to 8, ... Are sequentially read from the buffer memory means 23. In this way, first, the buffer memory means 23
Fields 3 to 10 are continuously written and read in and are output as they are through the image decompression means 25. For example, the decompressed data as shown in FIG. Writing to the image output memory means 26 will be performed only once (1 field). That is, the writing to the image output memory means 26 is performed by intermittently writing the field data continuously read from the buffer memory means 23. Here, under the control of the output memory control means 27, the final fields of each packet, namely, the field 10, the field 9, the field 8, ... Are intermittently and sequentially written in the image output memory means 26. Then
Since the reading from the image output memory means 26 is performed continuously as shown in FIG. 4 (d), the contents of the field 10 are read continuously 8 times, and then the field 9 is read. Content is read out eight times in succession, then the content in field 8 is read out eight times in succession, and a slow reproduction image is output as .... Reverse rotation slow reproduction is possible with the above operation sequence.

In the present embodiment, the last field of each packet is written in the image output memory means 26, but the present invention does not limit which field is fetched. Of course.

In this embodiment, although the 1/8 reverse slow reproduction is performed, the same packet contents are reproduced n times from the writing state of the buffer memory means 23 of FIG. 4A by the control of the buffer memory control means 24. (N is an integer) When controlling to read, and writing to the image output memory 26 is controlled to be intermittently written and continuously read as in the above example, a slow speed of 1 / (8 × n) It can be controlled. Similarly, if the number of fields in one packet is 4, it goes without saying that slow speed control at 1 / (4 × n) is possible.

The following describes skip reproduction in the forward rotation direction (skipping a predetermined number of fields to fast forward) and skip reproduction in the reverse rotation direction (skipping a predetermined number of fields to reverse fast forward).

A case will be described in which a mode signal for normal rotation skip reproduction is input as the mode input. Figure 5
Shows an operation sequence at the time of forward skip reproduction, and shows a disk access content in each packet unit and a sequence in which the image is output from the image output memory means 26 after it is written in the buffer memory means 23. ing.

FIG. 5A shows the contents of the buffer memory means 23 at the time of normal skip reproduction, and unlike the buffer memory contents at the time of normal reproduction, the writing from the disk medium 21 to the buffer memory means 23 is a packet. 1,
In response to the rewriting of 2, 3, ..., The read start address from the disk medium 21 is skipped in the forward direction by the predetermined number of fields corresponding to the double speed number for each packet. For example, when one packet has 8 fields and the normal rotation skip 4 × speed reproduction is performed, 8 × (4
The number of fields is skipped by -1) = 24. This read control of the disk medium is performed by the read address control means 22. Therefore, as shown in FIG. 5A, the fields 1 to 8 are read from the disk medium 21 as the packet 1 and written into the buffer memory means 23, and then the disk medium 2 as the packet 2.
The fields 33 to 40 are read from 1 and written in the buffer memory means 23. Similarly, the fields 65 to 72 are read from the disk medium 21 as the packet 3 and written in the buffer memory means 23.

Then, the reading from the buffer memory means 23 is performed in the same manner as in the normal reproduction, as shown in FIG. 5 (b). Therefore, the fields 1 to 8, 33 to 40, 65 to 72, ... Are sequentially read from the buffer memory means 23. As described above, first, the fields 1 to 8 are continuously written and read in the buffer memory means 23, and are output as they are through the image expansion means 25. For example, according to the read timing of the field 8, FIG. As shown in (c), the decompressed data is written in the image output memory means 26 only once (one field). That is, the writing to the image output memory means 26 is performed by intermittently writing the field data continuously read from the buffer memory means 23. Here, the final field of each packet, that is, the field 8, the field 40, the field 72, ... Is intermittently and sequentially written in the image output memory means 26 under the control of the output memory control means 27. Then, the reading from the image output memory means 26 is performed as shown in FIG.
As shown in (d), the contents of field 8 are read continuously 8 times, and then the contents of field 40 are read 8 times continuously. Further, next, the contents of the field 72 are read out eight times in succession, and a skip reproduction image is output like ... The forward rotation skip reproduction can be performed by the above operation sequence.

In this embodiment, the last field of each packet is written in the image output memory means 26, but the present invention does not limit which field is fetched. Of course.

In this embodiment, the normal 4 × normal skip reproduction is carried out. However, by controlling the read address control means 22 to appropriately set the read address skip interval of the disk medium 21, an arbitrary double speed number can be obtained. Can be set. However, the upper limit of the double speed depends on the performance of the disk device body.

Next, the case where a reverse skip reproduction mode signal is input as the mode input will be described. FIG. 6 shows an operation sequence at the time of reverse skip reproduction. The disk access contents in each packet unit and after the contents are written in the buffer memory means 23,
The sequence in which an image is output from the image output memory means 26 is shown.

FIG. 6A shows the contents of the buffer memory means 23 at the time of reverse skip reproduction, and unlike the buffer memory contents at the time of normal reproduction, the writing from the disk medium 21 to the buffer memory means 23 is packet 1 ，
2, 3, ... The reading start address from the disk medium 21 is skipped in the reverse direction by a predetermined number of fields corresponding to the double speed number for each packet. For example, when one packet has 8 fields and reverse skip quadruple speed reproduction is performed, 8 × (4
The number of fields is skipped by -1) = 24. This read control of the disk medium is performed by the read address control means 22. Therefore, as shown in FIG. 6A, for example, fields 65 to 72 are read from the disk medium 21 as a packet 1 and written into the buffer memory means 23, and then, as a packet 2, fields 33 to 40 from the disk medium 21 are read. It is read and written in the buffer memory means 23. Similarly, fields 1 to 1 from the disk medium 21 as packet 3
8 is read and written in the buffer memory means 23.

Then, the reading from the buffer memory means 23 is performed in the same manner as in the normal reproduction, as shown in FIG. 6 (b). Therefore, the fields 65 to 72, 33 to 40, 1 to 8, ... Are sequentially read from the buffer memory means 23. As described above, the fields 65 to 72 are continuously written and read in the buffer memory means 23, and are output as they are through the image decompression means 25. For example, in accordance with the read timing of the field 72, as shown in FIG. As shown in (c), the decompressed data is written to the image output memory means 26 once (1 field).
Just decide to do it. That is, the image output memory means 26
Is written by intermittently writing field data continuously read from the buffer memory means 23. Here, by the control of the output memory control means 27, the final field of each packet, that is, the field 72, the field 40, the field 8, ...
It is sequentially written into the image output memory means 26 intermittently.
Then, since the reading from the image output memory means 26 is performed continuously as shown in FIG. 6D, the contents of the field 72 are read continuously eight times, and then The contents of the field 40 are continuously read eight times, and then the contents of the field 8 are continuously read eight times, and a skip reproduction image is output as .... The reverse skip reproduction can be performed by the above operation sequence.

In this embodiment, the last field of each packet is written in the image output memory means 26, but the present invention does not limit which field is fetched. Of course.

In the present embodiment, the 4-fold reverse skip reproduction is performed. However, by controlling the read address control means 22 to appropriately set the read address skip interval of the disk medium 21, an arbitrary double speed number can be obtained. It can be set. However, the upper limit of the double speed depends on the performance of the disk device body.

As described above, according to the embodiment of the present invention, in any of the special reproductions of the forward slow reproduction, the reverse slow reproduction, the forward skip reproduction, and the reverse skip reproduction,
The control of the buffer memory means 23 is exactly the same as that at the time of normal reproduction, and it is not necessary to perform special address control as in the conventional case, and a high speed and low cost memory such as a FIFO memory can be used as the buffer memory means 23. . At the time of special reproduction, it is only necessary to control the read address of the disk medium 21 and the intermittent write control of the image output memory means 26. These controls may be simple controls. To control the read address of the disk medium 21, it is only necessary to change the contents of the command for the disk medium 21 according to the contents of the special reproduction mode during the special reproduction. The intermittent writing control of the image output memory means 26 may be a simple control synchronized with the read timing of the buffer memory means 21, which is completely common to the above-mentioned four special reproduction modes.

Next, the read address control of the disk medium 21 will be described. This control is performed by the read address control means 22. The read address control means 22 is configured in the CPU in the disk device. On the other hand, in a hard disk or the like, one logical block unit (hereinafter referred to as LBU) is configured in units of 512 bytes, for example, and addressing from the CPU is often designated by this LBU.

For the sake of simplicity, the amount of compressed 1-field image data written on the disk medium is assumed to be S [L
BU] and the number of access fields in one packet is F
In the case of [field], the following relational expression is established, where the head address (unit is LBU) of the packet currently being reproduced is A [NOW] and the head address to be accessed in the next packet is A [NEXT].

A [NEXT] = A [NOW] ± F × S × N (1) However, in the above formula, “+” is applied in the normal direction reproduction, and “−” is applied in the reverse direction reproduction. N is a value that changes in each reproduction mode described below.

Still reproduction ... N = 0. Slow reproduction ... N = 1 / (F × n) where n is an integer. Normal reproduction ... N = 1 However, equation (1)
"+" Is only "+"-Skip playback ... N = 2 Note that frame advance can be performed by still-slow (one time) -still control.

Therefore, the read address control in the CPU may be performed by changing N in the equation (1) according to each reproduction mode. That is, by designating the value of N in the relational expression (1), the playback mode can be designated and the start address of the packet to be read next from the disk medium in the playback mode can be easily set.

In the embodiments described above, the hard disk for magnetic recording / reproducing is described as the disk medium, but the present invention is not limited to this, and can be applied to an optical disk device using a laser beam or the like. You can

Further, it is needless to say that the present invention may be a disc device capable of recording and reproducing, or may be a disc device dedicated to reproduction.

[0079]

As described above, according to the present invention, special reproduction can be performed without performing complicated memory control as the buffer memory means, and a high-speed and cost-effective buffer such as a FIFO memory. It is possible to use a memory means, and it is possible to realize a cost-effective disk reproducing apparatus.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a disc reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a control operation of each circuit block during special reproduction in the apparatus of FIG.

FIG. 3 is a diagram showing an operation sequence of the apparatus of FIG. 1 during normal rotation slow reproduction.

FIG. 4 is a diagram showing an operation sequence during reverse slow motion reproduction of the apparatus of FIG.

5 is a diagram showing an operation sequence of the apparatus of FIG. 1 at the time of forward skip reproduction.

FIG. 6 is a diagram showing an operation sequence during reverse skip reproduction of the apparatus of FIG.

FIG. 7 is a diagram showing data transfer and addressing timing during compressed recording.

FIG. 8 is a diagram showing data transfer and addressing timing during decompression reproduction.

FIG. 9 is a block diagram showing a schematic configuration of a conventional disc recording / reproducing apparatus.

10 is a diagram showing an example of a recording format on a disc medium in the apparatus of FIG.

11 is a diagram showing the contents of a buffer memory during normal reproduction in the device shown in FIG.

FIG. 12 is a diagram showing an operation sequence during normal slow motion reproduction in the apparatus of FIG. 9;

13 is a diagram showing an operation sequence during reverse slow motion reproduction in the apparatus of FIG.

FIG. 14 is a diagram illustrating a control operation of each circuit block during special reproduction in the apparatus of FIG.

[Explanation of symbols]

 21 ... Disk medium 22 ... Read-out address control means 23 ... Buffer memory means 24 ... Buffer memory control means 25 ... Image decompression means 26 ... Image output memory means 27 ... Output memory control means 28 ... Mode input terminal 29 ... Video signal output terminal

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kuniaki Takahashi 3-3-9 Shimbashi, Minato-ku, Tokyo Toshiba Abu E. Co., Ltd.

Claims (8)

[Claims] 1. A disk medium on which digital image data is compressed and recorded, and control for reading out the data compressed and recorded on this disk medium in packet transfer units for a predetermined number of field images, and a disk medium for each packet. Read address control means for regularly increasing / decreasing the read start address of a predetermined field number or frame number unit according to the special reproduction mode, and writing compressed image data transferred in packet units from the disk medium, and rate conversion Buffer memory means for outputting to the next stage, buffer memory control means for controlling writing and reading of the buffer memory means, image decompressing means for decompressing and reproducing compressed image data read from the buffer memory means, Image expanded by this compression / expansion means Image output memory means for writing and reading data in field or frame units, and image output memory control means for intermittently performing write enable operation of the image output memory means in synchronization with the read timing of the buffer memory means. A disc reproducing apparatus characterized by being provided. 2. The disc reproducing apparatus according to claim 1, wherein the buffer memory means is a FIFO memory. 3. The read address control means increases the read start address of the disk medium for each packet in units of one field or one frame when the normal slow reproduction mode is specified as the special reproduction mode. The disc reproducing apparatus according to claim 1 or 2, characterized in that: 4. The read address control means reduces the read start address of the disk medium for each packet in units of one field or one frame when the reverse slow reproduction mode is specified as the special reproduction mode. The disc reproducing apparatus according to claim 1 or 2, characterized in that 5. The read address control means sets the read start address of the disk medium for each packet to a predetermined number of fields or a predetermined number of fields according to the skip interval when the normal rotation skip reproduction mode is designated as the special reproduction mode. The disk reproducing apparatus according to claim 1 or 2, wherein the number of frames is increased. 6. The read address control means, when the reverse skip reproduction mode is designated as the special reproduction mode, sets the read start address of the disk medium for each packet to a predetermined number of fields or frames according to the skip interval. The disk reproducing apparatus according to claim 1 or 2, wherein the disk reproducing apparatus reduces the value by several units. 7. The buffer memory control means, when the normal slow play mode or the reverse slow play mode is designated as the special play mode, from the state in which the packet data is written in the buffer memory means,
5. The disc reproducing apparatus according to claim 1, wherein the same packet content is controlled to be read n times (n is an integer). 8. The read address control means, if the amount of compressed 1-field image data written to the disk medium is S [LBU] and the number of access fields in one packet is F [field], Start address of the packet currently being reproduced (unit is LB
U) is A [NOW], the start address to be accessed in the next packet is A [NEXT], and control is performed so that the relational expression of A [NEXT] = A [NOW] ± F × S × N holds. Therefore, "+" is applied in the normal direction reproduction, "-" is applied in the reverse direction reproduction, N is a value that changes in each reproduction mode, and N = 0.
Still playback when is N, slow playback when N = 1 / (F × n) [n is an integer], normal playback when N = 1 [However, only “+” in the above formula], skipping when N = 2 The disc reproducing apparatus according to claim 1, wherein the disc reproducing apparatus is a reproducing apparatus.