JP2574405B2 - Video signal recording and playback device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording and reproducing a MUSE signal.

Conventional technology The MUSE system is a band compression system developed by NHK for transmitting high-definition television via broadcasting satellites. Its contents are NHK Giken Monthly Report Vol.27 (1985), IEICE Research Institute IE86-69 (1986), TV
Zendai 12-6 (1987), NHK Technical Research Vol. 39, No. 2, pp. 76
−111 (1987).

This is a band compression technology based on offset sub-sampling, which converts baseband HDTV signals to 8.1M.
Band compression to Hz. FIG. 2 shows a sampling pattern indicating the sample phase of each field of the MUSE system signal. As shown in FIG. 2, the sample phase makes one cycle in four fields.

FIG. 3 shows a basic configuration of a decoder for the MUSE system signal. In FIG. 3, 6 is an input terminal, 7 is a moving image processing circuit, 8 is a still image processing circuit, 9 is a motion detection circuit, 10 is a control signal detection circuit, 11 is a mixing circuit, and 12 is an output terminal.

In the MUSE signal decoder configured as described above, when the MUSE signal is input to the input terminal 6, the moving image processing circuit 7 generates a moving image signal by performing only interpolation within the field, and outputs the moving image signal to the mixing circuit 11. I do. Still image processing circuit 8
Uses a four-field signal, interpolates between frames, and then interpolates between fields. That is, a still image signal is created using all four types of sample points shown in FIG. I do. The motion detecting circuit 9 detects a moving region of the image by generating a difference between one frame and two frames of the input MUSE signal, generates a motion signal, and outputs the motion signal to the mixing circuit 11. The control signal detection circuit 10 detects the control signal in the MUSE system signal, and controls the data processing content and the output signal content of the still image processing circuit 8 and the motion detection circuit 9 according to the content of the control signal. Table 1 shows the contents of the control signals. Mixing circuit
An output terminal 12 mixes or switches the moving image signal and the still image signal for each pixel according to the motion signal.
Output to

As described above, the still image processing circuit 8 performs the interpolation process using all the sample points of the four fields to generate a still image signal. However, for the interpolation process, the sample phase of the sample points, that is, You need to know the positional relationship. Since the data indicating the sample phase is written in Bit Nos. 1, 9, and 10 of the control signals shown in the table, the content is detected by the control signal detection circuit 10 and the current value for the previous frame and the previous field is detected. The phase of the sample point in the field of is determined.

Problems to be Solved by the Invention After recording the above-mentioned MUSE signal on a VTR or the like, when further performing assemble editing or insert editing,
By simply combining the frame synchronization timing and the horizontal synchronization timing as in the prior art, the sampling pattern shown in FIG. 2 becomes four fields between three fields after the editing start point and three fields after the editing end point. The phase relationship of making a round in the circle is not satisfied.

When the assemble-edited or insert-edited MUSE signal is input to the MUSE signal decoder shown in FIG. 3, the sample phase between the current field sample point and the previous frame and the previous field sample point is determined. Even though the relationship is broken, the still image processing circuit 9 always performs the interpolation processing based on the contents of the control signal of the current field. . The still image processing image obtained at this time is deteriorated from the current image quality of the NTSC signal.

In the worst case, for example, when the image content is a still image, the motion information in the control signal shown in the table is 1 complete still image mode, and at this time, the MU shown in FIG.
The SE system signal decoder ignores the detection result of the motion detection circuit 9 and determines that the entire screen is a still image, and outputs the output from the still image processing circuit 8 to the output terminal 12 as it is. As a result, in the three fields after the editing start point and in the three fields after the editing end point, serious image quality deterioration over the entire screen occurs.

Using servo control or memory, it is conceivable to perform editing after adjusting the timing of the signal already recorded and the signal to be edited and recorded so that the sampling phase is the same as before editing, Already recorded It is necessary to inspect the content of the control signal for each signal and the signal to be edited and recorded, and a complicated servo control circuit for adjusting the timing and a frame memory are required. It gets bigger.

In view of the foregoing, an object of the present invention is to provide a video signal recording / reproducing apparatus capable of performing assemble editing and insert editing without considering the inter-frame and inter-field sample phases of a MUSE signal.

Means for Solving the Problems The present invention is a video signal recording / reproducing apparatus for recording / reproducing a MUSE system signal, comprising at least a recording / reproducing circuit and a control signal changing circuit, and performing assemble recording when performing assemble editing. A video signal recording / reproducing apparatus and a MUSE system signal, wherein a control signal content of a MUSE system signal in three fields after an assembling start point is changed by the control signal changing circuit and recorded by the recording / reproducing circuit. A video signal recording / reproducing apparatus for recording / reproducing a MUSE signal, which includes at least a recording / reproducing circuit and a control signal changing circuit, and performs three fields after the insertion start point of the MUSE signal to be insert-recorded when performing insert editing. The control signal content during the recording and reproduction by changing the control signal content by the control signal change circuit. The control signal content of the already recorded MUSE system signal during the next three fields from the end point of the insert is changed by the control signal change circuit and re-recorded by the recording / reproducing circuit. It is a video signal recording / reproducing apparatus characterized by the following.

Operation The present invention prevents the deterioration of the image quality of the reproduced image occurring during the next three fields from the assembling start point when the MUSE signal is reproduced after assembling and editing by the above configuration.
Further, when the MUSE signal is reproduced after insert editing, the deterioration of the image quality of the reproduced image occurring between the last three fields from the insert start point and the last three fields from the insert end point is prevented.

Embodiment 1 FIG. 1 shows a block diagram of a video signal recording / reproducing apparatus according to a first embodiment of the present invention. In FIG. 1, 1 is a MUSE signal input terminal, 2 is a recording / reproducing circuit, 3
Is a recording medium, 4 is a control signal changing circuit, and 5 is an output terminal.

In a MUSE signal decoder that decodes a reproduction MUSE signal into a baseband Hi-Vision signal, in addition to the basic functions described in the related art, Bit Nos. 16, 17, and 18 indicating motion information in a control signal of the MUSE signal. If the result of the detection by the control signal detection circuit 10 is all 1, that is, 7 in decimal, it is determined that the moving image mode is the perfect moving image mode, the motion detection circuit 9 operates the mixing circuit 11, and the moving image signal from the moving image processing circuit 7 Only to the output terminal 12. Hereinafter, the operation of the video signal recording / reproducing apparatus of this embodiment will be described.

First, a case of assembling and editing a MUSE signal will be described.

It is assumed that a MUSE system signal is recorded in the recording medium 3 in advance, and a MUSE system signal to be assembled is input to the MUSE system signal input terminal 1. When the assemble editing is started, the control signal changing circuit 4 changes the contents of the motion information in the control signal of the MUSE system signal input to the recording / reproducing circuit 2 to 7 or 3 The mode is changed to the moving image mode, and the recording / reproduction circuit 2 records the data on the recording medium 3.

At the time of reproduction, a reproduction MUSE signal reproduced from the recording medium 3 by the recording / reproduction circuit 2 is output to the output terminal 5. The playback MUSE signal output to the output terminal 5
When input to the SE signal decoder, the MUSE signal decoder normally performs the original decoding operation as described in the related art. However, the content of the motion information in the control signal may be 7 or the complete moving image mode. When detected by the control signal detection circuit 10, the mixing circuit 11 is operated by the motion detection circuit 9, and only the moving image signal from the moving image processing circuit 7 is output to the output terminal 12.

As described above, according to the present embodiment, when assembling and editing the MUSE signal, the content of the control signal for three fields after the assembling start point is changed and recorded, so that the MUSE signal decoder at the time of reproduction is The MU between the three fields is changed by the changed control signal.
By performing the moving image processing and outputting the SE system signal as the previous screen moving image, it is possible to prevent a large image quality deterioration occurring between the three fields due to the collapse of the sample phase relationship.

Next, the case of performing insert editing will be described. It is assumed that a MUSE signal is recorded in the recording medium 3 in advance, and a MUSE signal to be inserted is input to the MUSE signal input terminal 1. When insert editing is started, the control signal change circuit 4
Changes the content of the motion information in the control signal of the MUSE system signal input to the recording / reproducing circuit 2 to 7, that is, the complete moving image mode, during the last three fields from the insert editing start point. Record in 3.

When the insert editing is completed, the control signal change circuit 4 reads the contents of the motion information in the control signal of the MUSE system signal recorded in the recording medium 3 in advance for three fields from the end point of the insert editing, and records the data in the recording / reproducing circuit 2. To change to 7, ie, the complete moving image mode, and re-record. The re-recording method is, for example, to reproduce a target field on a recording medium with a preceding reproducing head and store it in a memory or the like, change the content of the control signal, and then record the data at the original position on the recording medium. Alternatively, the position where the motion information is recorded may be found by making the position of the synchronization signal or the like a guide, and overwriting may be performed.

At the time of reproduction, a reproduction MUSE signal reproduced from the recording medium 3 by the recording / reproduction circuit 2 is output to the output terminal 5. The playback MUSE signal output to the output terminal 5
When input to the system signal decoder, the MUSE system signal decoder normally performs the original decoding operation as described in the related art, but the content of the motion information in the control signal is
When the control signal detecting circuit 10 detects that the mode is 7, that is, the complete moving image mode, the motion detecting circuit 9 operates the mixing circuit 11 and outputs only the moving image signal from the moving image processing circuit 7 to the output terminal 12.

As described above, according to the present embodiment, when insert-editing the MUSE system signal, the contents of the control signal between three fields after the insert start point and between three fields after the insert end point are changed and recorded, During playback, the MU between the above 6 fields is
By performing the moving image processing as the previous screen moving image and outputting the SE system signal, it is possible to prevent a large image quality deterioration occurring between the six fields due to the collapse of the sample phase relationship.

In the first embodiment, when the content of the motion information in the control signal is 7, the MUSE signal decoder determines that the mode is the complete moving image mode. Either of 6 and 7 may be used as the index of the complete video mode. (0: normal mode,
1: perfect still image mode, 2: semi-still image mode, 3: scene change mode) Also, Bit No. 19, 21 to 32 may be used instead of the motion information part.

Next, a video signal recording / reproducing apparatus according to a second embodiment of the present invention will be described. The video signal recording / reproducing apparatus according to the second embodiment has the same configuration as that shown in FIG.

When the content of the motion information in the control signal is 0, that is, in the normal mode, the MUSE decoder uses the motion signal from the motion detection circuit 9 to output the pixel-by-pixel output from the moving image processing circuit 7 as described in the related art. A certain moving image signal and a still image signal output from the still image processing circuit 8 are mixed or switched and output. Therefore, in the case of a general moving image in which the content of the motion information in the control signal is 0, that is, in the normal mode, even if the editing is performed ignoring the sample phase, the motion detecting circuit remains in the next four fields from the editing point. 9 determines that many portions on the screen are motions, and outputs a large amount of moving image signals generated by the moving image processing circuit 7 from the mixing circuit 11, so that the image quality degradation is relatively small.

However, when editing is performed, the content of the motion information in the control signal for at least three fields after the assemble editing start point and for at least three fields after the insert editing start point and end point is 1, that is, completely stationary. When a situation such as the image mode occurs, that is, for example, when the general moving image and the still image whose motion information content in the control signal is 1 are insert-edited, three times after the editing point During the field, the motion detection circuit 9 determines that the entire screen is still because the motion information is 1, and forcibly outputs the still image signal generated by the still image processing circuit 8 from the mixing circuit 11. As a result, large image quality degradation occurs.

Therefore, in this embodiment, the same device as in the first embodiment is used.
The content of the motion information in the control signal in the next three fields from the editing start point and the end point is changed to 0, and the recording medium 3
To record.

During playback, the playback MUSE signal output to the output terminal 5 is
When the signal is input to the MUSE signal decoder, the MUSE signal decoder forcibly processes the image data in the next three fields from the edit point as the normal mode because the motion information content is 0. The situation where the still image signal due to the insertion is output to the entire screen and the image quality is greatly deteriorated is avoided.

As described above, according to the present embodiment, when editing the MUSE signal, the content of the control signal in the three fields after the edit point is changed and recorded, so that the MUSE signal decoder at the time of reproduction By processing and outputting the MUSE signal between the three fields as the previous screen normal mode, it is possible to prevent a large image quality deterioration occurring between the three fields due to the collapse of the sample phase relationship.

In the first and second embodiments, the recording medium 3 may be any type such as a magnetic tape, an optical disk, and a solid-state memory.

The recording format on the recording medium 3 may be any format as long as only assemble editing is performed.
When performing insert editing, the recorded MUSE
What is necessary is just to be able to change the content of the control signal part in the system signal later.

Also, the content of the control signal in the three fields after the edit point is changed at the time of recording. However, at the time of recording, an index signal is recorded at the edit point, for example, on a control track or the like. When detected, the content of the control signal for three fields of the reproduced MUSE signal after the detected point may be changed.

Effects of the Invention As set forth above, according to the present invention, it is possible to prevent a large deterioration in reproduction image quality that occurs at the start point of assemble editing of a MUSE signal and at the start and end points of insert editing. In addition, it is only necessary to partially change the content of the control signal of the existing MUSE system signal, and since a complicated servo control circuit and frame memory are not required, the circuit scale is not increased, and the practical effect is large.

[Brief description of the drawings]

FIG. 1 is a block diagram of a video signal recording / reproducing apparatus according to the first and second embodiments of the present invention, FIG. 2 is a waveform diagram of a sampling pattern showing a sample phase of a video portion of a MUSE signal, and FIG. FIG. 2 is a block diagram showing a basic configuration of a decoder for a MUSE signal. 1. MUSE signal input terminal 2. Recording / reproducing circuit 3.
…… Recording medium, 4 …… Control signal change circuit, 5…
... output terminal, 6 ... input terminal, 7 ... video processing circuit, 8
... Still image processing circuit, 9 ... Motion detection circuit, 10 ... Control signal detection circuit, 11 ... Mixing circuit, 12 ... Output terminal.

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kiyoshi Sasaki 1006 Kazuma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-60-191591 (JP, A) JP-A-61- 105985 (JP, A)

Claims (4)

(57) [Claims] 1. An apparatus comprising at least a recording / reproducing circuit and a control signal changing circuit.
A video signal recording / reproducing apparatus, characterized in that the control signal content of a MUSE signal to be assembled and recorded in three fields after an assembling start point is changed by the control signal changing circuit and recorded by the recording / reproducing circuit. 2. The video signal recording / reproducing apparatus according to claim 1, wherein the control signal changing circuit changes the content of the motion information in the control signal to a normal mode. 3. A system comprising at least a recording / reproducing circuit and a control signal changing circuit.
The control signal contents of the MUSE signal to be inserted and recorded in the last three fields from the insertion start point are changed by the control signal change circuit and recorded by the recording / reproducing circuit. A video signal recording / reproducing apparatus characterized in that the control signal content of the already recorded MUSE system signal is changed by the control signal changing circuit and re-recorded by the recording / reproducing circuit. 4. The video signal recording / reproducing apparatus according to claim 3, wherein the content of the motion information in the control signal is changed to a normal mode by a control signal changing circuit.