JPH09261591A - Digital video signal reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize smooth slow reproduction similarly entirely to the case with a VTR processed in the unit of fields in the case of slow-reproduction of a digital video signal recorded onto a medium while being high efficiency coded in the unit of a plurality of fields (group). SOLUTION: An output section of a high efficiency decoding circuit 32 is provided with two field memories 33, 34, in which data in the unit of groups reproduced from the high efficiency decoding circuit 32 are stored once to reproduce the data in the unit of fields in the case of slow reproduction repetitively, one frame is generated from two fields belonging to two groups reproduced continuously to realize the field output method in which the processing in the unit of fields is implemented and observed in the slow reproduction of the VTR.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video signal reproducing apparatus for slow reproduction of a video signal digitized and recorded on a medium such as a VTR or a disc.

[0002]

2. Description of the Related Art In order to record and reproduce a digital video signal having a large amount of information, a high efficiency coding technique for compressing the amount of data has become indispensable. For example, in consumer digital VTRs and digital video discs, the adoption of high-efficiency coding has become common because of the demand for smaller and longer media and the improvement in digital signal processing capability. Typical high efficiency encoding standards include the JPEG standard for compressing in units of 1 frame (2 fields) and the MPEG standard for compressing in more units of multiple fields, both of which are found in conventional devices. This is different from a recording / reproducing system such as a VTR in which recording / reproducing is performed in field units. However, even a VTR recorded by using such a high-efficiency coding is naturally required to have a slow reproduction function.

Before describing a slow reproduction system in a VTR or the like for highly efficient encoding and recording / reproduction in a unit of a plurality of fields, first of all, a general conventional method of recording / reproducing in a helical scan system by a rotary head with one field as one processing unit. An example of slow playback will be described for the VTR. In a rotary head type VTR, the reproducing head on the cylinder traces all tracks in sequence during normal reproduction, but during slow reproduction, the tape running speed becomes slower than during normal reproduction, so the reproducing head travels over multiple tracks. It will be traced repeatedly. But,
Since many current VCRs for broadcasting and business use have a movable head, the reproducing head can correctly scan the track not only during normal reproduction but also during slow reproduction. The movable head is, for example, a head attached to a cylinder via a piezo element, and the head can be displaced in the track width direction by applying a drive voltage to the element, so the head can be moved even during slow reproduction. You can surely trace on the track.

In a helical scan type VTR equipped with a movable head, it is possible to correct the deviation between the track formed on the tape and the reproduction scanning locus of the head, and reproduce them in a state in which both are in sync. In addition, it is possible to obtain a reproduced image without noise even during variable speed variable reproduction such as still or reverse reproduction. The following is a detailed description of the output during slow reproduction in the conventional VTR, which performs processing on a field-by-field basis with the above configuration.
However, the VTR shown below is a conventional VTR having a movable head and recording a video signal for one field on one track. First, FIG. 7 shows a schematic diagram showing a state of video output during normal reproduction. It is assumed that video output is performed from the left to the right in the figure as time passes. In FIG. 7, fields 1 and 2 are names of two fields forming one frame during normal reproduction, and frames A, B, C, and D are names added for convenience of distinguishing each frame. . The fields 1 and 2 and the frames A, B, C and D are information recorded on the tape. A frame on the video signal output by adding the sync signal to the information is referred to as a frame section. The frame section represents a unit that is treated as one frame in video output, and is a broadcast / commercial VTR.
Then, it is necessary to be continuous in all operation modes as well as during normal playback and slow playback. At the time of normal reproduction, the frames A, B, C, and D are coincident with the frame section, and the first half of the frame section is field 1 and the second half is field 2.

During reproduction at normal speed, each frame (each field) is sequentially output once, as shown in FIG.
That is, the field 1 of frame A, the field 2 of frame A, the field 1 of frame B, the field 2 of frame B, and so on are output. Next, FIG. 8 and FIG. 9 are schematic diagrams showing the state of video output during slow reproduction. FIG. 8 shows a 1/4 speed reproduction in the forward direction and FIG.
The figure shows the state during double speed reproduction. In the case of a VTR, at 1/4 speed or 1/2 speed, the tape speed itself becomes 1/4 or 1/2 of that in normal reproduction. However, even in slow reproduction, the rotation of the cylinder is the same as in normal reproduction, so the reproduction head traces the track a plurality of times, but each track is completely traced by the movable head. As shown in FIG. 8, at the 1/4 speed, the reproducing head traces the same track four times, so that the same field is repeatedly output four times. As shown in the figure, after the field 1 of the frame A is output four times, the field 2 of the frame A is output four times. That is, by outputting a video for one frame over a four-frame period,
Achieve double speed. The same applies to 1/2 speed shown in FIG.
By outputting the video for one frame over the two-frame section, 1/2 speed is realized.

As described above, in the case of 1/4 speed or 1/2 speed, the field output method is relatively easy to understand.
There are various slow speeds in R. The VTR achieves all slow speeds by tracing the track with a movable head and running the tape speed at a set slow speed. For example, 4 /
Consider the situation of video output at 5x speed (0.8x speed).

FIG. 10 is a schematic diagram showing the state of video output during 4/5 × slow speed reproduction. In the same manner as 1/4 × speed or 1/2 × speed, at 4/5 × speed, images for 4 frames are output in 5 frame intervals. As shown in the example of FIG. 10, 4 frames of the frames A to D are output in the 5 frame section. As an actual VTR state, the tape running speed is set to 4/5 times, and the movable head traces a track. 4/5 times speed is 1 of normal playback
Since the speed is close to the double speed, a state in which data for one frame is output only in one frame section as shown in FIG. 7 may occur.

For example, the frame A in FIG. 10 corresponds to this, which is the same as that in the normal reproduction. However, some fields will be traced twice because the tape speed is slightly slower than the normal playback speed. For example, the field 2 of the frame B and the field 2 of the frame D shown in FIG. As a result, 4/5 times speed is realized by inserting a total of 2 fields, one for each 1 field, into 5 frame intervals (the fields are repeated).

Considering the video output in the above state as a frame section, as can be seen from the state of the third frame section shown in FIG. 10 by repeating the field 2 of the frame B twice, for example, One frame section is formed and output by the field 2 of B and the field 1 of the following frame C. That is, in normal reproduction, data of two fields belonging to different frames are output in one frame section in slow reproduction. Such a state also occurs at the slow reproduction speed in many other cases, and by repeating a certain field, in the case of the forward direction, field 2 belonging to different continuous frames and field 1 following it form one frame section. To do. Similarly, in the case of reverse slow reproduction, a similar state occurs.

The slow output form described above is a common output form for VTRs that output video data every time one field worth of data is read and consequently form a frame section by external output, and is generally common. This is a slow output method common to VTRs. That is, the slow reproduction is performed by outputting the data one field at a time a plurality of times.

In the above example, the VTR having a movable head and recording one field on one track is taken as an example, but data for one field is recorded on one track or more tracks, but the internal processing is performed on a field-by-field basis. The same applies to the non-compressed digital VTR which is performed in step S1 and the digital VTR which performs high-efficiency encoding in one field unit and performs recording and reproduction. Further, in the case of the digital VTR, the movable head may not be used by using the memory. They implement slow playback by writing playback data that is traced a plurality of times during slow playback sequentially into the memory and outputting the data when one field of data is written into the memory.

What can be said in common with the conventional VTR as described above is that the slow reproduction is realized by reading data from the tape on the basis of the concept of field and repeating it in units of field. Next, let us consider a slow reproduction method in a VTR or a disk recorder that performs high-efficiency encoding and recording / reproduction in units of a plurality of fields (hereinafter, a plurality of fields which are units for performing high-efficiency encoding are referred to as a group).

From the beginning, these devices perform data processing with the group unit as the minimum unit. Therefore, when the slow unit is repeatedly played back in group units according to the slow playback speed, the result is repeated playback of multiple fields. However, it was pointed out that smooth slow playback cannot be performed on a moving screen. That is, in order to perform smooth slow playback, the conventional VT
As with R, processing in units of one field is indispensable instead of in units of a plurality of fields.

Therefore, in order to solve these problems, as described in JP-A-5-344472, JP-A-7-46528 and JP-A-7-203375, a high efficiency code is provided in units of a plurality of fields. There has been proposed a digital VTR, a disc player, or the like, which is capable of slow-playing a digitized digital video signal in field units.

The common point of the above-mentioned proposed techniques is that when the data recorded with high efficiency coding in units of groups (plural fields) is reproduced from the medium again in units of groups, the data is decoded with high efficiency and the slow reproduction is performed. By temporarily loading the group data into the memory, the group is decomposed into fields and repeatedly played back in field units, rather than being repeatedly played back in group units according to the slow speed, and smooth slow playback is realized. .

FIG. 11 shows an example of a block diagram of a digital video signal reproducing apparatus using the high efficiency encoding for slow reproduction of the conventional proposed technique. In FIG. 11, 90 is a reproduction circuit for processing a reproduction signal from a medium, 91 is an error correction circuit for error correction of reproduction data, 92 is a high-efficiency decoding circuit for decoding reproduction signals in group units, and 93 is a high-performance decoding circuit. A memory that can store the output from the efficiency decoding circuit 92 and can output the data for each field, and 94 is a memory control circuit that controls the memory 93. It is assumed that the conventional digital video signal reproducing device described below performs high-efficiency decoding with two fields as one group.

At the time of reproduction, the reproduction group data is supplied to the high-efficiency decoding circuit 92 after being subjected to error correction by the error correction circuit 91 via the reproduction circuit 90. The high-efficiency compounding circuit 92 decodes the data in units of groups, and the output is written in the memory 93. Decoded data is written to the memory 93 at one time, but output is performed by the memory control circuit 94 in units of fields. Memory 9 during slow playback
For example, when the output from 3 is repeated 4 times (1/4 speed), the memory is controlled so that the first field is repeated 4 times and then the other field is repeated 4 times (video output is the same as in FIG. 8). .

The state of video output during normal reproduction and slow reproduction of the conventional digital video signal reproducing apparatus of FIG. 11 will be described below. During normal reproduction, the output shown in FIG. 7 is naturally performed as in the conventional case. Next, considering slow playback at 1/2 speed in a state where slow playback in field units cannot be performed without using the above-mentioned proposed technique, images read out from the tape in units of groups (2 fields). The signal is repeated twice, resulting in an output as shown in FIG. As can be seen from FIG. 12, since two fields are repeatedly output as one unit, the output becomes fields 1.2.1 / 2 as in the case of frame A, and a moving image becomes unsightly.

Therefore, in the conventional proposed technique, after the video data for the group (2 fields) obtained as a result of the high efficiency decoding is once stored in the memory, the group is repeatedly output (FIG. 12), but instead the first half of the reproduction period. And in the second half 2
By repeating reproduction of one field (FIGS. 8 and 9), the same output as in the conventional VTR shown in FIGS. 8 and 9 is output.

There are four methods of reading the fields 1 and 2 which are one group once in the memory and then reading them in field units in the frame section instead of outputting the groups. Field 1 in one frame section
To read fields twice in one frame section • To read field 2 twice in one frame section • To read field 2 twice in one frame section
It is a method of continuously reading 1 and 1. Since the fourth reading method has a reversed time order of the fields and is used for backward reproduction, the first to third reading methods are used in the forward direction. In that case, it can be understood that the outputs of FIGS. 8 and 9 can be easily realized.

Next, consider the case of 4/5 times speed. Using 3 patterns from 1 to 3, 5 data of 4 frames
It can be considered that the output as shown in FIG. 13 is most smoothly output when output in the frame section.

[0022]

However, the above-mentioned conventional structure has the following problems. As described above, in the conventional broadcast / commercial VTR that was recorded in the field unit, in the slow reproduction, it was repeated in the field unit depending on the tape reproduction speed and the head trace position. In a VTR that performs high-efficiency encoding in units of a plurality of fields, a technique has been proposed in which slow reproduction is performed by reading from a tape in units of a plurality of fields and then reading from the memory in units of a field in order to perform smooth slow reproduction.

Comparing the slow reproduction methods of the above two devices, there is no difference in slow speed such as 1/4 speed or 1/2 speed, but as shown in the conventional example, it is close to 1 speed such as 4/5 speed. At a speed such as a speed at which a field is irregularly repeated, a big difference occurs in the output form. For example,
Comparing FIG. 10 and FIG. 13, it can be seen that the slower reproduced image in FIG. 10 is smoother. In the case of FIG. 10, the repetition in the field unit is 2 in 5 frame sections.
This is because, in the case of FIG. 13, both fields in the same frame are continuously repeated, so that it seems that the whole frame has stopped. That is,
In FIG. 10, the repeated portions are dispersed as shown in the figure, whereas in FIG. 13, they are concentrated. In FIG.
Since the frames A to C are the same as those in the normal reproduction, it seems that reproduction and still are repeatedly output, which gives a jerky impression. This difference is clearly visible and impairs the smooth motion of slow-motion images.

Such a difference between the two occurs at many slow reproduction speeds. In other words, it can be said that there are less cases in which the slow reproduction methods of both, such as ½ speed and ¼ speed, are the same among all the slow speeds. In slow reproduction of a VTR that performs high-efficiency encoding in units of multiple fields using the conventional proposed technique, instead of repeatedly writing multiple fields in a memory and then repeatedly reproducing the multiple fields, the fields are decomposed and repeatedly reproduced. Therefore, at one switching point of one group, which is also the switching point of reading from the memory, and at the switching point of the group to be reproduced next, the processing is always completed and the frame section delimiter and the group delimiter are the same. Occurs.

The present invention is to solve the above-mentioned problems, and when slow-reproducing a digital video signal which is highly efficient encoded in a unit of a plurality of fields and recorded on a medium, the last and the first of two groups to be continuously reproduced. It is an object of the present invention to realize slow reproduction that is smooth and has no unnatural appearance just like a conventional VTR that is processed in units of fields, by making a field into one frame.

[0026]

SUMMARY OF THE INVENTION To solve this problem, the present invention provides two high-efficiency digital video signals recorded in a medium, which are high-efficiency coded in units of groups each including a plurality of fields. The configuration is such that one frame is generated from two fields belonging to a group that is continuously reproduced.

As a result, the slow reproduction in the digital signal reproducing apparatus which is highly efficient coded in the unit of a plurality of fields can be obtained exactly like the conventional VTR which processes in the unit of a field.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is a medium in which m (m is an integer of 2 or more) fields is set as one group and high efficiency coded data is recorded in group units. In a digital video signal reproducing apparatus for reproducing the following, when the last field in one group which is reproduced from the medium and is highly efficient decoded and the first field of the next group which is subsequently reproduced / decoded are output as one frame This has the effect that the smooth slow reproduction exactly like the conventional VTR processed in the field unit can be realized.

According to a second aspect of the present invention, after the high-efficiency decoding, the slow reproduction is realized by writing once in the first memory in the group unit and repeatedly reading from the first memory in the field unit. In the digital video signal reproducing apparatus, by including the second memory for storing the field read from the first memory and delaying it by one field, the last field in one group reproduced from the medium and decoded efficiently And the first field of the next group to be played / decoded subsequently is set to 1
By providing a means for outputting as one frame, by adding a second field memory in the device of the conventional proposal technology capable of performing the slow reproduction in the field unit in the memory while performing the high efficiency decoding in the group unit, This has the effect of outputting two fields belonging to two groups as one frame.

According to the third aspect of the present invention, after high-efficiency decoding, by having a memory of a size equal to or larger than m fields for storing the decoded data, two fields belonging to two groups are output as one frame. By using a memory, it has an effect of outputting two fields belonging to two groups as one frame.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In the embodiment described below, 2
It is assumed that one field (m = 2) is used for one field and high-efficiency coding is performed, and that it is recorded on the medium. (Embodiment 1) FIG. 1 is a block diagram of a digital video signal reproducing apparatus according to claims 1 and 2 of the present invention. FIG.
In the figure, 90 is a reproducing circuit for processing a reproduced signal from the medium, 91 is an error correction circuit for correcting an error in the reproduced data, 92 is a high-efficiency decoding circuit for decoding the reproduced signal in units of groups, and 93 is a high-efficiency decoding circuit. A memory for storing the output from the digitizing circuit 92 and performing the output for each field, 94
Is a memory control circuit for controlling the memory 93, 10 is a field memory for recording the fields output from the memory 93, 11 is a switch for switching between using the output of the field memory 10 or the output of the memory 93, Reference numeral 12 is a frame section generation circuit that adds a sync or the like to the output and generates a frame section. Since 90 to 94 have the same configuration as the conventional example of FIG. 11, description thereof will be omitted.

The reproduction data output from the memory 93 during reproduction is supplied to the field memory 10. Memory 9
Before the group is switched at the output of 3, the data stored in the field memory 10 is the last field data in the memory 93. At that time, the switch 11 is switched to the side of the field memory 10 and the output from the field memory 10 is continued, so that the last field of the group and the first field of the following group output from the memory 93 are separated by the frame section. Generation circuit 1
Can be linked at 2.

FIG. 2 shows an example of FIG. 1 at 4/5 times speed.
The output (A) of the conventional digital video signal reproducing apparatus having the configuration shown in FIG. 1 and the output (B) of the digital video signal reproducing apparatus of the present invention are shown respectively. In FIG. 1, the output of the memory 93 is the same as that in FIG. The arrow drawn from (A) of FIG. 2 to (B) of FIG. 2 uses the output of the field memory 10 (indicated as “memory” in the figure) or the output of the memory 93 by switching the switch 11. Indicates that (displayed as path in the figure) is selected.

By using the field memory 10, (A) can be transformed into (B) output by giving one field delay to a specific field. FIG. 2B shows the same output as the conventional VTR shown in FIG. Thus, by adding the field memory 10 as the second memory, two fields belonging to two groups (for example, field 2 of frame B and field 1 of frame C in this embodiment) are output in one frame section. Therefore, it is possible to compensate for the drawbacks of the conventional digital video signal reproducing apparatus that performs high-efficiency decoding in a plurality of fields, and it is possible to perform smooth slow reproduction.

(Embodiment 2) FIG. 3 shows claim 1 of the present invention.
3 is a block diagram of the digital video signal reproducing device shown in FIGS. In FIG. 3, reference numeral 30 is a reproduction circuit for processing a reproduction signal from a medium, 31 is an error correction circuit for performing error correction on reproduction data, 32 is a high-efficiency decoding circuit for decoding reproduction signals in group units, and 33 is a reproduction circuit. Sometimes a first field memory for storing the output from the high efficiency decoding circuit 32 for one field, 34 is a field memory 33.
A second field memory similar to the above, 35 is a memory input changeover switch for distributing the data output from the high-efficiency decoding circuit 32 to the field memories 33 and 34, and 36 is an output of the field memories 33 and 34. A memory control circuit for controlling the input / output of the field memories 33 and 34, the memory input selection switch 35 and the memory output selection switch 36, and 38 a field memory 3
3 is a frame section generation circuit that adds a sync or the like to the outputs of 3 and 34 to generate a frame section.

First, the operation will be described using the case of normal reproduction. FIG. 4 shows a high-efficiency decoding circuit 32 during normal speed reproduction.
Group data input (Fig. 4 (A)) and output (Fig. 4 (B)), and subsequent field memory input (Fig. 4 (C)) and output (Fig. 4) It is explanatory drawing which shows the relationship of (D). 4, groups A, B, C, D, E, and F shown in FIG. 4A are data of groups reproduced from the media and output from the error correction circuit 31, and memories 33 and 34 are field memories of FIG. 33,
34 respectively. Input to the high-efficiency decoding circuit 32 is performed in units of groups, and is input continuously during normal reproduction. Each time the input of data for one group is completed, the high-efficiency decoding circuit 32 performs decoding, and as shown in (B), it is decoded into two fields in this example. FIG. 4 shows that group A is decoded into fields 1 and 2 of frame A after decoding, group B is decoded into frame B, and so on. As shown in (C), the output of the high efficiency decoding circuit 32 is sequentially written in the field memories 33 and 34 by the memory control circuit 37.

The memories 33 and 34 shown in (C) indicate memories in which data is written, and the displays of frames A and B and fields 1 and 2 indicate the contents of data written in the respective memories. The data written in the memory is again stored in the field memories 33 and 34 as shown in (D).
Is read from the frame section, and the frame section generation circuit 38 adds a sync to form a frame section in the video output.

Next, the slow reproduction will be described. Similarly during slow reproduction, reproduction data is supplied to the high efficiency decoding circuit 32 via the reproduction circuit 30 and the error correction circuit 31.
In the slow reproduction, the reproduction data is output over a long time, for example, in order to trace the same track a plurality of times, as compared with the normal reproduction, but in the high efficiency decoding circuit 32, one group of data which is a processing unit is output. If you do not have them, you cannot start decryption.

The processing unit for assembling the group data from the data repeatedly input a plurality of times is in the high-efficiency decoding circuit 32 in the present embodiment. It is a configuration that efficiently decodes and outputs. The timing at which the group data is input can be easily considered from the frame reading timing of the slow playback of the conventional VTR. The reading timing of data at the time of 1/2 × slow reproduction in the conventional VTR will be considered again with reference to FIG. Although the recorded contents are different, the tape speed control at the time of slow reproduction and the head tracing method are the same both in the past and in the present embodiment.

In the present embodiment, the data compressed in units of one frame (two fields) is treated as one group. Therefore, considering the case where one group is divided into two tracks and recorded, frame A in FIG. The frame unit such as or B can be simply replaced with the group unit in the present invention. In the normal reproduction, although the frame unit and the group unit have different data sizes, they are the units that are sequentially read out in accordance with the reproduction speed. It can be seen from FIG. 9 that it takes twice as much time to read each frame from the tape completely at 1/2 speed as compared with the normal reproduction speed. That is, it can be considered that it takes twice as long as the time required for normal reproduction to complete one group.

In FIG. 5, group data is input ((A) in FIG. 5) and output ((B) in FIG. 5) to the high-efficiency decoding circuit 32 at the time of 1/2 speed reproduction, and is followed by this. Input ((C) in Figure 5) and output ((D) in Figure 5) to the field memory
It is explanatory drawing which shows the relationship. 1 / as shown in FIG.
At the time of double speed reproduction, it is inputted to the high efficiency decoding circuit 32 in a time twice as long as the normal speed. In the high-efficiency decoding circuit 32, the decoding process is started at the same time when the data of the group are prepared, and the output is written in the field memories 33 and 34. The written data is read twice, but if it is read twice in a frame, the unnatural movement as shown in FIG. 12 will occur.
Smooth slow output is realized by reading the same field data from the field memory twice each as shown in FIG.

Next, with reference to FIG. 6, a state at the time of 4/5 × speed reproduction is shown. FIG. 6 shows input of group data ((A) of FIG. 6) and output (B of FIG. 6) to the high-efficiency decoding circuit 32 during 4/5 × speed reproduction, and subsequent field memory operation. FIG. 7 is an explanatory diagram showing the relationship between the input ((C) of FIG. 6) and the output ((D) of FIG. 6). As can be understood from the frame reproduction timing of FIG. 10, group data is input to the high-efficiency decoding circuit 32 as shown in FIG. In the high-efficiency decoding circuit 32, the decoding process is started at the same time when the data of the group are prepared, and the output thereof is sent to the field memories 33 and 34 in (C) of FIG.
Is written as follows. The written field data is read out a plurality of times, but by reading from the memories 33 and 34 as shown in FIG. 6D, smooth slow playback similar to that of a conventional VTR that processes in units of one field is performed. It can be performed.

Although the two field memories 33 and 34 are used in the present embodiment, any configuration can be used as long as the last field of the group and the first field of the next group can be continuously output. Such a memory configuration may be used. For example, one dual-port memory having a group size capable of writing and reading at the same time may be used.

In the digital video signal reproducing apparatus of the present embodiment, one frame (2 fields) is one group which is a unit of high efficiency coding, but a plurality of more fields may be one group. The digital video signal reproducing device of the present invention may be a digital disc player as well as a VTR.

[0045]

As described above, according to the present invention, even in a digital video signal reproducing apparatus which reproduces a medium in which a plurality of fields are grouped and high efficiency coded data is recorded on a group unit basis, the unit is one field unit. It is possible to obtain the advantageous effect that the smooth slow reproduction similar to that of the VTR which is processed in step 1 can be performed at any slow speed.

Further, there is an advantageous effect that a defect in the field slow of the conventional proposed technique in the conventional digital video signal reproducing apparatus using the high-efficiency coding is compensated and a complete slow reproduction can be performed. To be

[Brief description of drawings]

FIG. 1 is a first block diagram of a digital video signal reproducing device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing the output states of the conventional digital video signal reproducing apparatus of FIG. 11 and the digital video signal reproducing apparatus of the present invention of FIG. 1 during 4/5 × speed reproduction.

FIG. 3 is a second block diagram of a digital video signal reproducing device according to an embodiment of the present invention.

4 is an explanatory diagram showing the relationship between input / output to / from a high-efficiency decoding circuit and input / output to / from a field memory during normal speed reproduction in the digital video signal reproducing device of FIG.

5 is a block diagram of the digital video signal reproducing device of FIG.
Explanatory diagram showing the relationship between the input / output to the high-efficiency decoding circuit and the input / output to the field memory during the 2 × speed reproduction

6 is a block diagram of the digital video signal reproducing device of FIG.
Explanatory diagram showing the relationship between input / output to a high-efficiency decoding circuit and input / output to / from a field memory at / 5 × speed reproduction

FIG. 7 is a schematic diagram showing a state of video output during normal reproduction of a conventional VTR that records and reproduces in units of one field.

FIG. 8 is a schematic diagram showing the state of video output during 1/4 speed reproduction of a conventional VTR that records and reproduces in units of one field.

FIG. 9 is a schematic diagram showing a state of video output during 1 / 2-speed reproduction of a conventional VTR that records and reproduces in units of one field.

FIG. 10: Conventional VTR for recording / reproducing in 1-field units
Schematic diagram showing the state of video output during 4/5 speed playback

FIG. 11 is a block diagram of a conventional digital video signal reproducing apparatus which reproduces a signal recorded with high efficiency encoding in units of two fields.

[FIG. 12] 1 / of a conventional digital video signal reproducing apparatus for reproducing a signal recorded with high efficiency encoding in units of two fields
Schematic diagram showing the state of video output during double speed playback

FIG. 13 shows 4 / of a conventional digital video signal reproducing apparatus which reproduces a signal recorded with high efficiency encoding in units of 2 fields.
Schematic diagram showing the state of video output during 5x speed playback

[Explanation of symbols]

 10 field memory 11 switch 12 frame section generation circuit 30 reproduction circuit 31 error correction circuit 32 high efficiency decoding circuit 33 first field memory 34 second field memory 35 memory input changeover switch 36 memory output changeover switch 37 memory control circuit 38 Frame section generation circuit 90 Reproduction circuit 91 Error correction circuit 92 High efficiency decoding circuit 93 Memory 94 Memory control circuit

Claims (3)

[Claims] 1. A digital video signal reproducing apparatus for reproducing a medium in which high efficiency coded data is recorded in units of m fields (m is an integer of 2 or more) as one group and reproduced from the medium. A digital video signal reproducing apparatus configured to output, as one frame, the last field in one group that has been decoded with high efficiency and the first field of the next group that is subsequently reproduced and decoded. 2. A digital video signal reproducing apparatus configured to realize slow reproduction by performing high-efficiency decoding, then once writing to the first memory in group units, and repeatedly reading from the first memory in field units,
By having a second memory that stores the fields read from the first memory and delays them by one field,
2. The means according to claim 1, further comprising means for outputting, as one frame, the last field in one group reproduced from the medium and highly efficiently decoded and the first field of the next group reproduced / decoded subsequently. Digital video signal playback device. 3. A means for outputting two fields belonging to two groups as one frame by having a memory having a size of m fields or more for storing the decoded data after highly efficient decoding. 1. The digital video signal reproducing device according to 1.