JPH04267686A - Reproduction device - Google Patents

Abstract

PURPOSE:To observe a still picture of a content for a long time without stopping the reproduction of a reproduction device. CONSTITUTION:A data by four fields of a data sequentially reproduced from a DAT 50 is fed alternately to RAMs 22A, 22B. When one of the RAMs 22A, 22B is in writing state, the other is in reading state. When a reproduction pattern fixing switch 38 is turned on to set a still mode, even when the data write by four fields is finished, the write and read state of the RAMs 22A, 22B are not switched. A repetitive data by 4 fields from the RAMs 22A, 22B is fed to a MUSE decoder 28 and a still picture is displayed on a monitor television receiver 29. In the still mode, one of the RAMs 22A, 22B is read continuously for the same pattern data. Thus, a still picture of a content is observed for a long time without stopping the reproduction in the reproduction device.

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 sequentially reproducing data for a plurality of screens of a MUSE signal from a recording medium to generate still image data.

0002

[Prior Art] As a method for compressing the transmission signal band of television signals, MUSE (Multiple Sub-
nyquist Sampling Encoding
) is known. In the MUSE encoder, band compression is performed by line offset subsampling in the motion system, and by field offset and frame offset subsampling in the stationary system.

On the other hand, in the MUSE decoder, in the motion system, an image is reproduced using only the signal of the current field through intra-field interpolation, and in the stationary system, the image is reproduced using the signals of the current field and the past three fields through inter-frame and inter-field interpolation. be done. As a result, the full resolution is achieved in a stationary system, and blurring of the image is prevented, although the resolution is reduced to 1/4 in a moving system.

[0004] In the MUSE system, a high-definition television signal (video signal bandwidth = 20 MHz) is band-compressed and transmitted. According to the high-definition standard, the number of scanning lines per frame is 1125, the interlace ratio is 2:1, the aspect ratio is 16:9, the field frequency is 60 Hz, and the line frequency is 33,750 Hz.

FIG. 4 shows the format of a television signal (hereinafter referred to as "MUSE signal") transmitted using the MUSE method. The MUSE signal has 480 samples of data on each of 1125 horizontal lines, with a frame pulse added to the beginning of each frame and a horizontal synchronization signal added to the beginning of each line.

[0006]

By the way, it is conceivable to record and reproduce such a MUSE signal as still image data, for example, on a DAT (digital audio tape recorder).

[0007] In order to obtain the full resolution, it is sufficient to extract and record data in units of four fields from the MUSE signal for a moving image, and to reproduce a still image using the four fields' worth of data during playback.

[0008] The MUSE signal is sampled at 16.2 MHz, and in the case of 4 fields (2 frames), 112
5×2×480=1,080,000 samples. If one sample is 8 bits, it becomes 8,640,000 bits (≈8.24 Mbits).

If these four fields of data are recorded and reproduced as still image data on a DAT, the data recording and reproduction speed on the DAT is 1,536,000 bits (4
8kHz x 2 channels x 16 bits)/sec, so
It will take 5.625 seconds. That is, in the video system, 4×1/60≈66.7 msec worth of data becomes 5.625 seconds worth of data in the DAT system.

[0010] Here, if data for one screen is extracted from the MUSE signal at intervals of several seconds and the data is continuously recorded and then simply reproduced, the still image will be updated with new content at intervals of several seconds.

However, there is a desire to continue viewing a still image of a certain content for a long time without stopping the playback operation of the DAT. For example, there is a case where audio is simultaneously recorded on a DAT and the user wants to view a still image of a certain content carefully while listening to the audio continuously.

[0012] Accordingly, the present invention makes it possible to continue viewing a still image of a certain content for a long time without stopping the playback operation on the playback device.

[0013]

[Means for Solving the Problem] The present invention provides a playback screen fixing switch in a playback device that outputs data that is sequentially played back screen by screen via a memory means. This allows the data to be read to be fixed.

[0014]

[Operation] Even if data to be sequentially reproduced screen by screen is supplied to the memory means, by operating the playback screen fixing switch 38, the data of the same screen is repeatedly read out from the memory means. Therefore, it is possible to continuously display still images of a certain content without stopping the playback operation in the playback device.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. This example is an example in which the MUSE signal is recorded and reproduced as still image data using DAT.

FIG. 2 shows the configuration of the recording system. In the figure, a satellite broadcast signal captured by a satellite broadcast (BS) antenna 1 is supplied to a BS tuner 2. B.S.
The MUSE signal output from the tuner 2 is band-limited by a low-pass filter 3, further converted into a digital signal by an A/D converter 4, and then transferred to sides a and b of a changeover switch 5.
It is supplied to RAMs 6A and 6B as buffers via the side.

The output signal of the A/D converter 4 is supplied to a synchronization detection circuit 7, and the frame pulse signal and horizontal synchronization signal detected by the synchronization detection circuit 7 are supplied to a controller 8. The controller 8 has a frequency of 48kHz x 4 = 192kHz from the DAT50 in order to synchronize with the DAT50.
A system clock CLK is supplied.

Writing and reading to and from RAMs 6A and 6B are controlled by a controller 8.
6B, when one is in the write state, the other is in the read state. In other words, M in RAM6A or 6B.
When data for 4 fields of the USE signal is written as still image data, RAM 6B or 6A is written respectively.
to DAT50 data recording speed (1,536,000
Four fields of data are read out in synchronization with the data rate (bits/second). In this case, data for 4 fields (8, 6
40,000 bits) is read out with a time of 5.625 seconds.

Here, while data for four fields is read from one RAM at a recording speed of DAT50, many field signals are supplied as write signals to the other RAM, and the data contents are sequentially updated. Four fields of data are always stored.

After the reading of four fields of data from one RAM is completed, the write and read states of the RAMs 6A and 6B are switched. At this time, data for four fields immediately before switching is stored in the other RAM.

Still image data read from the RAMs 6A and 6B is supplied to the a side of the changeover switch 10 via the a side and b side of the changeover switch 9, respectively. Switching of the changeover switches 5 and 9 is controlled by a controller 8. The selector switch 5 is set to a when the RAM 6A is in the write state.
When connected to the side and RAM6B is in the write state b
connected to the side. The changeover switch 9 is connected to the a side when the RAM 6A is in the read state, and is connected to the b side when the RAM 6B is in the read state.

Reference numeral 11 denotes a synchronization generation circuit, and a synchronization pattern signal PS outputted from this synchronization generation circuit 11 is supplied to a fixed terminal on the b side of the changeover switch 10. The operation of the synchronization generating circuit 11 and the switching of the changeover switch 10 are controlled by the controller 8.

That is, immediately before data for four fields is supplied to the a side of the changeover switch 10, the synchronization generating circuit 1
1 outputs a synchronization pattern signal PS. Although not mentioned above, the reading of four fields of data from the RAMs 6A and 6B is started after the synchronization pattern signal PS is output. In addition, the changeover switch 10 has 4
When data for a field is supplied, it is connected to side a, and when synchronization pattern signal PS is supplied to side b, it is connected to b.
connected to the side.

Therefore, the changeover switch 10 outputs the synchronization pattern signal P at the beginning of each of the four fields of data.
The output with S added is output (shown in Figure 3), which is D
The signal is supplied to the AT 50 and recorded.

Next, FIG. 1 shows the configuration of the reproduction system. In the figure, four fields of data sequentially reproduced from the DAT 50 are alternately supplied to RAMs 22A and 22B as buffers via the a side and b side of the changeover switch 21, and are written therein.

Furthermore, the reproduced signal of the DAT 50 is supplied to the synchronization detection circuit 23. This synchronization detection circuit 23 detects the synchronization pattern signal PS added to the beginning of four fields of data, and the detection signal SD is sent to the controller 2.
4 as a signal (heading signal) indicating the start timing of four fields of data. Further, the controller 24 is supplied with a 192 kHz system clock CLK from the DAT 50.

Writing and reading of the RAMs 22A and 22B is controlled by a controller 24. Switching of the changeover switch 21 is controlled by a controller 24. The switching of the changeover switch 21 is performed by the controller 24.
When the RAM 22A is in the write state, it is connected to the a side, and when the RAM 22B is in the write state, it is connected to the b side.

When one of the RAMs 22A and 22B is in a write state, the other is in a read state. In other words, when data for four fields of the MUSE signal is written to RAM 22A or 22B, each RAM
Four fields of data are repeatedly read from 22B or 22A in synchronization with a 16.2 MHz clock.

A playback screen fixing switch 38 is connected to the controller 24 . Fixed switch 3 in normal mode
8 becomes the still mode, and when the fixed switch 38 is turned on again in this still mode, the mode returns to the normal mode.

In normal mode, 4 to one RAM
After writing the data for the field, the RAM
The write and read states of 22A and 22B are switched. Then, the data to be reproduced from the DAT50 is written to the other RAM, and at the same time
Data for four fields is read out repeatedly.

On the other hand, in the still mode, even if writing of data for four fields to one RAM is completed, the R
The writing and reading states of AM22A and 22B cannot be switched. And again, DAT50 to one RAM
At the same time, the data to be reproduced from the other R is written.
Data for four fields (the same data as the data read last time) is repeatedly read from AM.

Four fields of data (still image data) repeatedly read out from the RAMs 22A and 22B are supplied to the MUSE decoder 28 via the a side and b side of the changeover switch 25.

The switching of the changeover switch 25 is controlled by the controller 24, and when the RAM 22A is in the read state, it is connected to the a side, and when the RAM 22B is in the read state, it is connected to the b side.

The video signals (for example, R, G, and B signals) output from the MUSE decoder 28 are supplied to a monitor television 29, and a still image is displayed on the monitor television 29.

In this example, by turning on the fixed switch 38 to enter the still mode, one of the RAMs is
Even if the writing to the RAMs 22A and 22B is completed, the writing and reading states of the RAMs 22A and 22B cannot be switched. Therefore, the same four fields of data are read out continuously from the RAMs 22A and 22B, and the still image that was displayed when the fixed switch 38 was turned on and the still mode was set is displayed on the monitor TV 29 as it is. continues to be.

According to this example, even in the still mode, D
Since the AT 50 performs a playback operation, if audio, for example music, is simultaneously recorded on the magnetic tape, the audio can be continuously heard and a still image of a certain content can be viewed for a long time.

In the above embodiment, the synchronization pattern signal PS is added to the beginning of four fields of data, but the recording system adds dummy data of a predetermined length (for example, continuous data of 128 levels). , 0 level and 2
It is also possible to add 55 levels of alternating continuous data, etc.), and the reproduction system can detect the end of this dummy data and recognize the start of four fields of data.

Furthermore, in the above-mentioned embodiment, four fields are used as one unit of still image data, but the same applies to cases where two fields or one field are used as one unit of still image data. Can be applied.

Furthermore, in the above embodiment, two RA
Although M22A and 22B (6A, 6B) are used, it is also possible to use one or three or more.

Furthermore, in the above embodiment, the MUSE signal is played back as still image data by the DAT50, but when playing back other television signals (for example, NTSC system), or using other playback equipment. The same can be applied to the case of further reproduction.

[0041]

[Effects of the Invention] According to the present invention, by operating the playback screen fixing switch, data on the same screen can be repeatedly read out from the memory means, and certain content can be read out repeatedly from the memory means without stopping the playback operation in the playback device. Still images can be displayed continuously. As a result, if audio, for example music, is also recorded on the recording medium, it is possible to listen to the audio continuously and to continue viewing a still image of a certain content for a long time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a reproduction system according to an embodiment.

FIG. 2 is a block diagram showing the configuration of a recording system according to an embodiment.

FIG. 3 is a diagram showing the structure of recorded data of DAT.

FIG. 4 is a diagram showing the format of a MUSE signal.

[Explanation of symbols]

2 BS tuner 6A, 6B, 22A, 22B RAM 7, 23 Synchronization detection circuit 8, 24 Controller 11 Synchronization generation circuit 28 MUSE decoder 29 Monitor TV 38 Playback screen fixing switch 50 DAT

Claims (2)

[Claims] 1. A playback device that outputs data that is sequentially played back screen by screen via memory means, wherein a playback screen fixing switch is provided, and data read out from the memory means can be fixed by operating the playback screen fixing switch. playback device. 2. The memory means includes first and second memory sections, and when one of the first and second memory sections is in a write state, the other is in a read state,
The playback data is written in screen units to the first or second memory section, and by operating the playback screen fixing switch, writing to the first and second memory sections is performed after writing of data for one screen is completed. 2. The reproducing apparatus according to claim 1, wherein switching of the reading state can be stopped.