JPH07193780A - Magnetic recording/reproducing device - Google Patents

Abstract

PURPOSE:To attain a specific effect of correspondence between two moving pictures even when only one source for video signals exists. CONSTITUTION:A VTR deck 9 records a 1st video signal outputted from a source 15 through a switching circuit 14, a gain variable amplifier 7 and an adder circuit 8. The the deck 9 rewinds a part of a tape to reproduce the recorded contents and a reproduced signal is digitized by an A/D conversion circuit 1 through the circuit 14 and the digital signal is compressed by a picture compressing circuit 2 and stored in a memory 3. Then a 2nd video signal is inputted from the source 15 to the amplifier 7 through the circuit 14, the 1st video signal is read out from the memory 3, expanded by a picture expanding circuit 4 and converted into an analog signal by the circuit 5 and the analog signal is inputted to a gain variable amplifier 6. Both video signals obtained by turning the gain of the amplifier 7 from '0' to '1' and turning that of the amplifier 6 in reverse are mutually added by the circuit 8 and the added result is video-recorded in the deck 9, so that consecutive recording based upon the dissolution of two moving pictures can be attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus such as a video tape recorder (VTR), and more particularly to a special effect such as dissolve or wipe applied when connecting a plurality of video signals.

[0002]

2. Description of the Related Art In recent years, VTR-integrated video cameras have rapidly become widespread as they have become smaller, and have become more sophisticated. As one of the functions, there is a fader or wipe used for producing a special effect at the time of continuous shooting. These special effects at the time of continuous shooting are often used not only in a VTR-integrated video camera but also in editing work after shooting by a stationary VTR or the like. The special effect that is applied when the screen is switched from the first shooting scene to the second shooting scene is that when the video signal source is one video camera and the recording device is one VTR deck, as in a VTR integrated video camera. , Which are different depending on the case where a plurality of VTR decks are used as video signal sources such as editing work. This will be described below by taking a dissolve using fade-in / fade-out as an example.

When there is only one video signal source (captured by a video camera) as in a VTR integrated video camera, for example, as shown in FIG. 4, the first shooting scene a fades out and the screen becomes solid white. Then, the second shooting scene b fades in, and the screen is simply switched from moving image → white screen → moving image.

On the other hand, a plurality of V
When there are a plurality of video signal sources by using the TR deck, the first shooting scene is reproduced on the first VTR deck and the second shooting scene is reproduced on the second VTR deck, as shown in FIG. In addition, the fade-out of the first shooting scene a and the fade-in of the second shooting scene b can be performed at the same time to realize the dissolve. That is,
The screen can be switched by a special effect (dissolve) of moving picture to moving picture.

By the way, even if there is only one video signal source as in a VTR integrated video camera, one video signal
A memory capable of storing fields or more is prepared, and as shown in FIG. 6, one screen of the end portion t0 of the first shooting scene a is loaded into the memory and the second shooting scene b is acquired. When the still image stored in the memory is read out and faded out at the same time as the start of, the second image capturing scene (moving image) b is faded in at the same time to realize the dissolve of the still image fade-out and the moving image fade-in. it can. In this case, the screens can be switched by the special effect of still image versus moving image.

However, in the case of a single video signal source such as a VTR integrated video camera, the screen can be switched by a special effect of still image to moving image, but the video signal can be obtained by using two or more VTR decks. Since it is not possible to switch the screen due to the special effect of moving image to moving image as in the case where there are two or more sources of, it is said that the switching of the screen between the first shooting scene and the second shooting scene becomes monotonous. There was a flaw. To avoid this drawback, V
The TR integrated video camera is equipped with a large-capacity memory,
The end portion from t0 to t1 of the first shooting scene a shown in FIG. 6 is stored as a moving image in the large-capacity memory, and then stored in the memory at the same time when the recording of the second shooting scene b is started. By dissolving the video of the first shooting scene a and fading it out, and fading in the second shooting scene (video) b at the same time, it is possible to realize the dissolve of the video fade-out and the video fade-in. However, this requires the above-mentioned large-capacity memory, and since the cost of this large-capacity memory is high, the VTR-integrated video camera becomes expensive and has a drawback that it is not practical.

[0007]

When connecting the first and second shooting scenes, special effects such as dissolve and wipe may be applied. At this time, when there is only one video signal source, the still image-to-video special effect (dissolve) is applied to the still image of the first shooting scene and the moving image of the second shooting scene stored in the memory as described above. ), You can switch the screen, but this had the drawback of being monotonous and lacking in fun. Therefore, if a memory with a capacity capable of storing a moving image for the time required for the special effect is prepared, the first shooting scene can be stored as a moving image and the screen can be switched by the special effect (dissolve) of moving image to moving image. However, since the memory capacity becomes very large, the device becomes expensive and impractical. Therefore, when there is only one video signal source as in a VTR-integrated video camera, there is a drawback that the special effect of moving picture-to-motion cannot be realized. .

It is therefore an object of the present invention to eliminate the above-mentioned drawbacks and to provide a magnetic recording / reproducing apparatus capable of performing a special effect of moving picture to moving picture even if there is only one video signal source.

[0009]

SUMMARY OF THE INVENTION The present invention is a magnetic recording / reproducing apparatus which has a single video source and records and reproduces a video signal generated from this video source on a tape. Storage means for compressing and storing one of the video signals obtained by reproducing the tape, reading means for expanding the video signal read from the storage means to the original video signal, and reading means And a special effect control means for creating a video signal having a special effect by using one of the obtained video signal and the video signal generated from the video source or the video signal obtained by reproducing the tape. Have.

[0010]

In the magnetic recording / reproducing apparatus of the present invention, the storage means compresses and stores either the video signal generated from the video source or the video signal obtained by reproducing the tape. The reading means decompresses the video signal read from the storage means to obtain the original video signal. The special effect control means creates a video signal having a special effect using either the video signal obtained from the reading means, the video signal generated from the video source, or the video signal obtained by reproducing the tape. This makes it possible to obtain a moving image-to-moving image special effect even if there is only one video signal source.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a magnetic recording / reproducing apparatus of the present invention. 1 is an A / D conversion circuit for converting a reproduced video signal into a digital signal, 2 is an image compression circuit for compressing the digital video signal, 3 is a memory for storing the compressed video signal, and 4 is read from the memory 3. An image expansion circuit for expanding a video signal, 5 a D / A conversion circuit for converting a digital video signal into an analog video signal, 6 a variable gain amplifier for changing the level of a video signal input from the D / A conversion circuit 5, Reference numeral 7 is a variable gain amplifier for changing the level of the video signal input from the switching circuit 14, 8 is an addition circuit for adding the video signals output from the variable gain amplifiers 6 and 7, and 9 is an image input from the addition circuit 8. A VTR deck 10 for recording a signal on a magnetic tape (not shown) or reproducing this tape controls a compression circuit and a decompression circuit to read / write a video signal from / to the memory 3. Cormorant memory control unit, 11 a gain control unit for controlling a gain of the variable gain amplifier 6, 12 V for controlling the operation of the VTR deck 9
A TR deck control unit, 13 is a special effect control unit for controlling the memory control unit 10, the gain control unit 11 and the VTR deck control unit 12 to apply a special effect to a screen switching unit, and 14 is a source of an input video signal. Is a switching circuit for switching between. Reference numeral 15 is a video signal source such as a video camera.

Next, the operation of this embodiment will be described. The switching circuit 14 is switched to the source 15 side, and a video signal captured by a video camera or the like is input from the source 15 to the variable gain amplifier 7 and the A / D conversion circuit 1 through the switching circuit 14. Initially, the gain of the variable gain amplifier 7 is set to 1 and the gain of the variable gain amplifier 6 is set to 0 by the gain control unit 11. Therefore, the video signal input from the switching circuit 14 is input to the VTR deck 9 via the variable gain amplifier 7 and the adding circuit 8 and recorded on the magnetic tape by the VTR deck 9. At this time, VTR deck 9
Is controlled by the VTR deck controller 12 to operate in the recording mode.

After that, the switching circuit 14 is switched to the VTR deck 9 side, and then the VTR deck controller 12 controls the VRT.
When the tape recorded on the deck 9 is controlled to be rewound a little and reproduced, after the video signal reproduced on the VTR deck 9 is input to the A / D conversion circuit 1 through the switching circuit 14 and converted into a digital signal, It is input to the image compression circuit 2. At this time, the memory control unit 10 controls the image compression circuit 2 and the memory 3, compresses the video signal reproduced by the VTR deck 9 by the image compression circuit 2, and then stores it in the memory 3.

Next, the switching circuit 14 is switched to the source 15 side, the VTR deck 9 is rewound to the position where it was previously rewound, and the video signal from the source 15 is input to the variable gain amplifier 7, and the memory is also stored. The compressed video signal read from the memory 3 by the control unit 10 is expanded by the image expansion circuit 4 to be converted into an original video signal, and this video signal is further converted into an analog signal by the D / A conversion circuit 5. Input to the variable gain amplifier 6. At the same time, the special effect control unit 13 controls the gain control unit 11 to change the gains of the variable gain amplifier 6 and the variable gain amplifier 7 according to a predetermined rule. As a result, the adder circuit 8 inputs the two video signals whose levels are changed by the variable gain amplifiers 6 and 7 and adds them, and outputs the added video signal to the VTR deck 9. At this time, the VTR controller 12
Records the composite video signal input from the adder circuit 8 in order to operate the VTR deck 9 in the recording mode. After that, when the gain of the variable gain amplifier 7 is 1 and the variable gain amplifier 6 is
, The VTR deck 9 continues to record only the video signal of the source 15 on the tape.

The magnetic recording / reproducing apparatus of this example can continuously shoot the first video signal and the second video signal by the special effect described below by the above basic operation. That is,
The special effect of the continuous shooting is a dissolve in which the first video signal fades out and at the same time the second video signal fades in, a wipe that separates the display areas on the screen of the first video signal and the second video signal, After the first video signal becomes a mosaic and the size of the mosaic gradually increases, the second video signal is gradually changed from a large mosaic to a smaller mosaic, and finally a second video signal is connected by a mosaic. There are photographs etc. Here, in order to realize the special effect of moving picture to moving picture, conventionally, a video signal source for the first video signal (VTR deck, video camera, etc.) and a video signal source for the second video signal are required. It was On the other hand, in this example, one video signal source 15 can be used to perform the special effect of moving picture to moving picture.

FIG. 2 is a diagram showing, as an example of the above-mentioned special effect, a procedure for continuous shooting of video signals when the dissolve is applied by the present apparatus. In step 201, the VTR deck 9 records the first video signal photographed by the source 15 such as a video camera, and in step 202, the tape recording the first video signal is rewound in the VTR deck 9. At step 203, the first video signal (used for the special effect portion) of the portion rewound by the VTR deck 9 is reproduced, and the first video signal of this portion is image-compressed by the image compression circuit 2. , In the memory 3. Step 20
After rewinding the tape on the VTR deck 9 at step 4, the levels of the second video signal input from the source 15 and the first video signal read from the memory 3 are respectively set at step 205. The video signals obtained by the addition by the addition circuit 8 after being changed by the variable gain amplifiers 7 and 6 are VTRs.
Record on deck 9 and then VT only the second video signal
Continue recording on R deck 9. At this time, the first
Of the variable gain amplifiers 6 and 7 are controlled so that the video signal of No. 2 fades out and the second video signal fades in, and the first video signal and the second video signal are fed for the first n seconds of step 205. Then it is taken by the dissolve.

Here, the above steps 201 to 205
The procedure will be described in accordance with the operation of the apparatus shown in FIG. The first video signal obtained by the video signal source 15 of the video camera or the like is passed through the switching circuit 14, the variable gain amplifier 7 whose gain is fixed to 1 and the adding circuit 8, and is the same as in the normal photographing by the VTR deck 9. Is recorded on the tape (step 201). At this time, the gain of the variable gain amplifier 6 is zero.

Here, it is assumed that the special effect, that is, the dissolve is performed for n seconds. The VTR deck 9 is controlled to rewind the tape for n seconds required for the special effect (step 202), and the switching circuit 14 is switched to the VTR deck 9 side. Then V
At the same time as playing the tape on the TR deck 9 for n seconds,
In real time, the reproduced video signal is converted into a digital signal by the A / D conversion circuit 1, this is compressed by the image compression circuit 2, and the compressed video signal is stored in the memory 3 (step 2).
03). By playing back the tape for n seconds, a compressed video signal (moving image) is stored in the memory 3 for n seconds. Next, the VTR deck 9 is controlled to rewind the tape again for n seconds (step 204), the switching circuit 14 is set to the source 15 side, and the recording standby state for the next scene is set.

At the same time when the recording of the next scene, that is, the second video signal is started, the memory control unit 10 reads the first video signal stored in the memory 3 in real time, and the first video signal is stored.
The video signal of is restored to its original state by being expanded by the image expansion circuit 4, and is converted into an analog video signal by the D / A conversion circuit 5. At this time, the second video signal is the variable gain amplifier 7
In addition, the first video signals stored in the memory 3 are input to the variable gain amplifier 6 respectively, and n required for the dissolve.
The gain of the variable gain amplifier 7 is 0 to 1 over a period of 2 seconds.
The special effect control unit 13 controls the gain control unit 11 so that the gain of the variable gain amplifier 6 changes from 1 to 0. By this control, as shown in step 205, the first video signal and the second video signal are generated by one video signal source.
It is possible to realize the dissolve between the moving images of the video signal.

According to the present embodiment, the video signal compressed by the image compression circuit 2 is temporarily stored in the memory 3. Therefore, even if the capacity of the memory 3 is not so large, the memory 3 can be used for a special effect. Even in the device shown in FIG. 1 in which a moving image can be stored and the source of the image signal is one using this moving image, the first image signal and the second image signal are connected by the image-to-image dissolve. You can take a picture.
Moreover, as described above, since the capacity of the memory 3 does not need to be so large, the dissolve can be realized without increasing the cost of the device.

In the above embodiment, the operation when the first video signal and the second video signal are connected and shot by using the dissolve has been described, but the first video signal and the second video signal can be taken by the same method.
The display area of the video signal of is divided, and the display area of the first video signal is gradually reduced to 0 at the end, and the display area of the second video signal is gradually increased to the end of this second Wipe only the display area of the video signal, or the first video signal becomes a mosaic, and after the size of this mosaic gradually increases, the second video signal gradually changes from a large mosaic to a small mosaic. Finally, it is also possible to perform joint shooting with a mosaic of only the second video signal.

There are various methods for compressing the video signal by the image compression circuit 2 shown in FIG. 1, but any signal compression method may be used in this example. However, since the compression rate differs depending on the signal compression method, if a method with a low compression rate is used, the capacity of the memory 3 becomes large and it becomes impractical. The image data stored in the memory 3 may be a frame image or a field image,
In the special effect, the field itself is sufficient because the effect itself is more important than the sharpness and sharpness of the image, and the memory 3 is desired to have a small capacity. Further, in the above embodiment, the method of applying the special effect to the analog video signal has been described. However, even if the second video signal is converted into a digital signal and the special effect is applied by the digital signal together with the first video signal. It has the same effect. Also, if the input video signal is a digital signal, the A / D conversion circuit 1 is not necessary, and a special effect is applied to this digital signal and this is output as it is to the VTR deck 9 capable of inputting a digital signal. As an alternative, the D / A conversion circuit 5 can be omitted.

The present invention also includes increasing the compression rate of the video signal with the passage of time in the time required for the special effect. This will be described with reference to the embodiment shown in FIG. The gain of the variable gain amplifier 6 for the first video signal decreases from 1 to 0 as time elapses in n seconds due to dissolve, so that image deterioration due to image compression / expansion is time-consuming for the human eye. It becomes difficult to understand as time passes. For example, when DCT (Discrete Cosine Transform) + Huffman coding is used as the image compression method, it is assumed that when a certain image 301 as shown in FIG. Here, since the high frequency part mainly expresses the sharpness of the image, time elapses due to the dissolve and the variable gain amplifier 6 is passed.
As the gain of 1 approaches 0, the image of the first video signal becomes lighter, and it becomes difficult for the human eye to distinguish. By utilizing this, the data of the high frequency component of the first video signal can be gradually prevented from being used as time passes. Here, FIG. 3 is a conceptual diagram of DCT (discrete cosine transform). Reference numeral 301 is an original image on which DCT is performed, and 302 is an original image 30.
The distribution of the spatial frequency when 1 is converted by DCT is shown.

For example, when each frequency of the first video signal is obtained as 8-bit data by the DCT, 8 bits are fully used for low frequency components, and the effective number of high frequency components is 7 bits, 6 bits, Less than or equal to 0
The total amount of data is reduced by completely truncating the data as a bit. Then, Huffman coding is used for this data. In this case, the image compression rate depends on the number of effective bits at each frequency.
By changing the number of effective bits of each frequency of the first video signal over time in n seconds and gradually reducing the data amount of the high frequency component, the compression rate of the first video signal over time can be reduced. Change can be realized. The effective bit of each frequency
The change of the number, that is, the change of the compression rate is performed in one field period of the image, one frame period, or an integral multiple thereof.

In the case of wipe, the display area on the screen is switched due to the special effect of continuous shooting, and the display area of the first video signal is gradually reduced.
When storing the video signal of 3 in the memory, only the data of the area necessary for display is stored in the memory 3 out of the n seconds required for the special effect, so that the capacity of the memory 3 can be reduced. . Further, when the size of the mosaic of the first video signal increases with the passage of time required for the special effect, the image data stored in the memory 3 decreases with the size of the mosaic, and the capacity of the memory 3 decreases. it can. In the above example, the method of increasing the compression rate by DCT + Huffman coding has been described, but the compression rate can be increased by the same idea in any other compression method. The control for increasing the compression ratio of the video signal is performed by the memory control unit 10 in FIG.

[0026]

As described above, according to the magnetic recording / reproducing apparatus of the present invention, even if there is only one video signal source, a special effect of moving picture to moving picture can be achieved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a magnetic recording / reproducing apparatus of the present invention.

FIG. 2 is a diagram showing a procedure for continuous shooting of video signals when the apparatus shown in FIG. 1 is used for dissolving.

FIG. 3 is a conceptual diagram of DCT (discrete cosine transform).

FIG. 4 is an explanatory diagram when performing continuous shooting using the fade-out and fade-in functions.

FIG. 5 is an explanatory diagram of a case where a plurality of VTR decks are used as video signal sources to perform continuous shooting by dissolve.

FIG. 6 is an explanatory diagram when performing continuous shooting by dissolving still images versus moving images.

[Explanation of symbols]

1 ... A / D conversion circuit 2 ... Image compression circuit 3 ... Memory 4 ... Image expansion circuit 5 ... D / A conversion circuit 6, 7 ... Gain variable amplifier 8 ... Addition circuit 9 ... VTR deck 10 ... Memory control section 11 ... Gain Control unit 12 ... VTR deck control unit 13 ... Special effect control unit 14 ... Switching circuit 15 ... Source

Claims (5)

[Claims] 1. A magnetic recording / reproducing apparatus which has a single video source and records and reproduces a video signal generated from the video source on a tape, and is obtained by reproducing the video signal generated from the video source or the tape. Storage means for compressing and storing one of the video signals, reading means for expanding the video signal read from the storage means to the original video signal, video signal obtained from the reading means and the video A magnetic recording / reproducing apparatus comprising: a special effect control means for creating a video signal having a special effect by using either a video signal generated from a source or a video signal obtained by reproducing the tape. . 2. The special effect control means creates a video signal for connecting the video signal generated from the video source to the video signal obtained from the reading means by dissolve. Magnetic recording / reproducing device. 3. The special effect control means creates a video signal for connecting the video signal obtained from the reading means with the video signal generated from the video source by wipe. Magnetic recording / reproducing device. 4. The special effect control means creates a video signal for connecting the video signal obtained from the reading means with the video signal generated from the video source in a mosaic manner. Magnetic recording / reproducing device. 5. The magnetic recording / reproducing apparatus according to claim 1, wherein said storage means gradually increases the compression ratio of the video signal stored therein with the passage of time.