JPH0522702A - Reproducer for muse signal - Google Patents

Abstract

PURPOSE:To obtain the reproduction picture with appropriate picture quality even in slow reproduction. CONSTITUTION:A reproducing circuit 14 reproduces a MUSE signal to be recorded in a recording medium. A control signal detecting circuit 16 detects a control signal from the output of the reproducing circuit 14 and a control signal rewriting circuit 18 rewrites the specified part of the detected control signal into content corresponding to slow reproduction. A still picture mode, for example, is adopted. A switch 22 replaces the control signal part of the reproduced MUSE signal by the output of the control signal rewriting circuit 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus for sub-sample time base compression multiplexed high-definition television signals.

[0002]

2. Description of the Related Art As a band compression method for high-definition television signals, a MUSE method ("MU") for subsampling a high-definition television signal so as to make a cycle of four fields.
SE method development ", NHK technology research, Vol. 39, No. 2, 1987) is known. Fig. 2 shows a sampling pattern of the MUSE method. The MUSE method is used for transmission by a broadcasting satellite. ..

Further, if a high-definition television signal is recorded on a magnetic tape like a conventional television signal,
Since it is difficult to obtain a practical recording time, a high-definition television signal band-compressed by the MUSE system (hereinafter referred to as MUS
It is called E signal. ) Has also been proposed for recording and reproducing a) on a magnetic tape. In such a MUSE signal recording / reproducing apparatus, the reproduction output during standard reproduction (that is, during reproduction at the same speed as during recording) is the MUSE signal itself. To get the original high definition television signal, the replayed MU
The SE signal must be decoded by the MUSE decoder. In order for the MUSE decoder to decode the MUSE signal, the sub-sampling information is necessary, which is the MU.
It is included as a control signal in the SE signal.

As is well known, the control signal of the MUSE signal is 32 bits of bits # 1 to 32, the bit # 9 indicates the sub-sampling phase of the luminance signal in each field, and the bit # 10 is the sub-channel of the chroma signal. Define the sample phase. In addition, bits # 16, 17, and 18 are motion information, where 0 is normal, 1 is a completely still image, 2 is a quasi-still image, 3 is a scene change, and 44 to 7 indicate the degree of motion. For other details, refer to the above document.

[0005]

However, for example, MUS
When the E recording / reproducing apparatus is reproduced at a speed different from that at the time of recording, the reproduction output is not a signal which makes a complete high-definition television signal by going through four fields. Generally, 1-field MUS for slow playback at 1 / k speed
The E signal is repeatedly output over k fields. Figure 4
2 shows an example of a sampling pattern of reproduction output when slow reproduction of the signal shown in FIG. 2 is performed at 1/2 speed. Data of field # 4n is repeatedly output over two fields, and thereafter, fields # (4n + 1), # are similarly output.
The data of (4n + 2), ... Is output.

That is, in the 1/2 × slow reproduction, only data for 2 fields is output in any 4 field period. Therefore, the MUSE decoder restores a high-definition television signal from the data of two fields by still image processing or moving image processing. In the still image processing, the MUSE decoder uses an odd field (line 4
7, 48, ..., 562: luminance signal), the data of the upper line is used for each sample, and the data originally located in the diagonal direction is located next to the horizontal direction. Deteriorates. Further, in the case of moving image processing, a blurred image results, which is noticeable in slow playback.

The present invention is a MUS that overcomes these drawbacks.
It is intended to present an E signal reproduction device.

[0008]

A MUSE signal reproducing apparatus according to the present invention comprises a reproducing means for reproducing a MUSE signal recorded on a recording medium, and a reproducing M output from the reproducing means.
Control signal detecting means for detecting a control signal of the USE signal, rewriting means for rewriting a predetermined portion of the control signal detected by the control signal detecting means, and control of the reproduced MUSE signal during reproduction at a speed different from that during recording. It is characterized by comprising switching means for replacing the signal with the control signal rewritten by the rewriting means.

[0009]

By the above means, the control signal is rewritten to the content corresponding to the reproduced MUSE signal and output when reproducing at a speed different from that at the time of recording. As a result, it is possible to obtain a high-definition television signal with good image quality from the MUSE decoder by using the reproduced MUSE signal.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. Reference numeral 10 is a MUSE signal reproducing apparatus which is an embodiment of the present invention, and 12 is a MUSE decoder. In the MUSE signal reproducing apparatus 10, 14 is a reproducing circuit for reproducing and outputting the MUSE signal recorded on the magnetic tape T by using the rotary head, and 16 is the MUS output from the reproducing circuit 14.
A control signal detection circuit for detecting the control signal from the E signal, and 18 is a control signal rewriting circuit for rewriting and outputting the control signal detected by the control signal detection circuit 16 as described later.

Reference numeral 20 is a delay circuit for delaying the output of the reproduction circuit 14 by a time corresponding to the signal delay by the control signal detection circuit 16 and the control signal rewriting circuit 18, and 22 is normally connected to the a contact, which will be described later. A predetermined period b according to a switching control signal from the system control circuit 24
It is a switch connected to the contact. Specifically, the switch 22 always selects the output of the delay circuit 20 during standard reproduction, and the MU of the output of the delay circuit 20 during predetermined special reproduction.
Connect to the b contact at the control signal part of the SE signal,
The output of the control signal rewriting circuit 18 is substituted. The output of the switch 22 becomes the output of the reproducing device 10.

When standard reproduction is instructed by operating the operation key 30, the system control circuit 24 causes the capstan control circuit 28 to rotate the capstan C at the same rotation speed as that at the time of recording. At the time of standard reproduction, the reproduced MUSE signal output from the reproducing circuit 14 is directly applied to the MUSE decoder 12 via the delay circuit 20 and the switch 22. That is, the system control circuit 24 always connects the switch 22 to the a contact. As a result, the reproduced signal from the switch 22 becomes the original MUSE signal itself, and the MUSE decoder 12 decodes the MUSE signal and outputs a high quality television signal.

Next, special reproduction in the VTR of this embodiment will be described.

When a special reproduction command is input by the operation keys 30, the system control circuit 24 controls the capstan control circuit 28 so as to drive the capstan C at a designated speed. As a result, the tape T runs at the desired speed.

In this embodiment, the rotary head in the reproducing circuit 14 is driven by an actuator such as a bimorph element or a voice coil so that the rotary head is traced in parallel with the helical track, and a good reproduced signal can be obtained. .. The DTF control circuit 26 controls the operation of the actuator according to the reproduction speed by the system control circuit 24.

Further, in the present embodiment, it is assumed that one field of MUSE signal is recorded for one helical track on the tape, and the MUSE signal is good for each field by the actuator at any reproduction speed. The signal shall be reproduced.

The operation during slow reproduction at ¼ speed or less will be described. At this time, the control signal detecting circuit 16 detects the control signal inserted in each field in the reproduced MUSE signal output from the reproducing circuit 14 and supplies it to the control signal rewriting circuit 18. The control signal rewriting circuit 18 uses the bit # 9 of the control signal.
, The C sub-sample phase of bit # 10, and the motion information of bits # 16, 17, and 18 are rewritten. Specifically, the Y sub-sample phase and the C sub-sample phase are inverted by "0" and "1" for each frame.
The motion information is a completely static image in mode 1. Since the control signal has check bits for error detection and correction in addition to these information bits, these check bits are also rewritten according to the rewritten information bits.

The delay circuit 20 outputs the reproduction MUSE output from the reproduction circuit 14 for a time corresponding to the operating time of the control signal detection circuit 16 and the control signal rewriting circuit.
Delay the signal. Therefore, the control signal rewriting circuit 18 has the same timing as the timing when the control signal of the reproduced MUSE signal is input to the a contact of the switch 22.
Is the rewritten control signal to the switch 22b.
Output to the contact. The system control circuit 22 switches the switch 22 to the b contact at the timing when the control signal is input to the a and b contacts of the switch 22 according to the detection timing of the control signal by the control signal detection circuit 16. As a result, the control signal of the reproduced MUSE signal is replaced by the control signal rewritten by the control signal rewriting circuit 18.

For example, when the MUSE signal having the pattern shown in FIG. 2 is slowly reproduced, the reproduced signal becomes a pattern shown in FIG. That is, when the data of the field recorded on the magnetic tape with the Y sub-sampling phase of "0" is played back in slow motion, as shown in FIG. 3, the sampling data at the horizontal position a of the 47th line is in the first field. It is fitted in the horizontal position a of the 47th line and in the horizontal position a of the 609th line in the second field. Here, the Y sub-sample phase is rewritten to "1", and in the third field, it is fitted in the horizontal position b of the 47th line, and in the fourth field it is fitted in the horizontal position b of the 609th line. The same applies to the other data, and this is repeated thereafter.

The MUSE decoder 12 processes a moving image / still image according to a control signal included in the MUSE signal from the switch 22. In the case of slow reproduction, since the motion information in the control signal has been rewritten to the complete still image mode, the MUSE decoder 12 performs still image processing. Therefore, the MUSE decoder 12 can obtain a high-definition television signal having a sharpness and no blur.

In slow reproduction of ⅓ times or more, the control signal rewriting circuit 18 sets the motion information of bits # 16, 17, 18 of the control signal to the extent of motion 4 to 7.
Rewrite one of the above. As a result, a moving image with less blur can be obtained.

Although the case of the slow reproduction has been described, it goes without saying that the same effect can be obtained for the frame advance reproduction and the high speed search reproduction.

[0024]

As can be easily understood from the above description, according to the present invention, it is possible to obtain a reproduced image with little image quality deterioration from the MUSE signal reproduced at a speed different from that at the time of recording.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a sampling pattern of a MUSE signal.

FIG. 3 is a sample pattern of a reproduced MUSE signal during slow reproduction.

FIG. 4 is a sample pattern during slow playback in a conventional example.

[Explanation of symbols]

10: MUSE signal reproducing device 12: MUSE decoder 14: reproducing circuit 16: control signal detecting circuit
18: Control signal rewriting circuit 20: Delay circuit
22: Switch 24: System control circuit 26: DT
F control circuit 28: Capstan control circuit 30: Operation key C: Capstan T: Magnetic tape

Claims (1)

Claim: What is claimed is: 1. A reproducing means for reproducing a MUSE signal recorded on a recording medium, and a reproducing M outputted from the reproducing means.
Control signal detecting means for detecting a control signal of the USE signal, rewriting means for rewriting a predetermined portion of the control signal detected by the control signal detecting means, and control of the reproduced MUSE signal during reproduction at a speed different from that during recording. A MUSE signal reproducing apparatus comprising a switching means for replacing a signal with a control signal rewritten by the rewriting means.