JPH08125968A - Digital television signal recording and reproducing device and digital television signal reproducing device - Google Patents

Abstract

PURPOSE: To provide a high-speed reproduced image easy to see by optimally deciding a picture updating period corresponding to double-speed at the time of high-speed reproduction. CONSTITUTION: On the recording side, data for high-speed reproduction to output an image at the time of high-speed reproduction are generated from inputted digital television signals by a data generator 1 for high-speed reproduction, the format of the data is transformed corresponding to updating period information 22 for deciding the optimum picture updating period corresponding to double-speed at the time of high-speed reproduction, and these transformed data for high-speed reproduction are recorded on a recording medium. At the time of high-speed reproduction, the format of regenerative signals is transformed by a deformatter 10 and the data for high-speed reproduction are recomposed into the data format the same as that at the time of input by a data recomposer 11 for high-speed reproduction, so that the high-speed reproduced image can be outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing device and a reproducing device for a compressed digital television signal.

[0002]

2. Description of the Related Art Currently, the development of package media for recording image, voice, and other data as digital signals is in progress. Since an image signal has a very large amount of information, if it is recorded on a recording medium as it is, the amount of medium used becomes very large, which is not suitable for consumer use. Therefore, the data compression is performed to reduce the consumption of the recording medium to the extent that it can be used for consumer use. MPE used in the video / audio signal coding method of digital television signals, which is being put to practical use in the United States and Europe.
The method called G (Moving Picture Expert Group) is the one that most meets this demand at present. In MPEG, inter-picture predictive coding technology is used for time-axis compression of image signals. For package media, fast forward, rewind,
Since reverse playback and playback from the middle are basically required, M
In order to satisfy these requirements, the PEG is provided with a function called GOP (Group Of Pictures) in which some moving images of a certain unit are put together so that independent reproduction can be performed in that unit. The GOP usually has three screens, an intra-picture coded screen called an I picture, a forward inter-picture predictive coded screen called a P picture, and a bidirectional predictive coded screen called a B picture. Exists. At the time of high-speed reproduction, the data of the I picture or P picture in it is usually output.

In high speed reproduction of an image recorded on a disc such as a CD-I, I picture data is sequentially output. For example, if one GOP is composed of nine screens, one out of nine becomes an I picture. At 9x speed, I picture data for every 9th screen is output, and at 18x speed, 18 pictures are output.
Outputs I-picture data for every screen. FIG. 14 shows the relationship between the double speed and the update cycle at this time. However, in FIG. 14, “x” indicates “double speed”. In the case of FIG. 14, the screen update cycle is always constant at any speed.

[0004]

The problems to be solved by the present invention will be described. When recording and reproducing a digital television signal encoded by inter-picture coding such as MPEG, I picture data or P picture data is outputted in order to output an image whose content can be understood even at high speed reproduction. Even at double speed, the screen update cycle becomes the same, and there is a problem that the viewer does not know how many times the data is being reproduced.

Further, there is no display for displaying the double speed at the time of high speed reproduction, so that there is a problem that it is difficult to know how many times the screen is currently fast forwarded.

[0006]

A first aspect of the present invention.
In the digital television signal recording / reproducing apparatus described above, the recording side inputs a digital television signal and generates high-speed reproduction data for outputting an image from the digital television signal during high-speed reproduction. Means, an update cycle information storage means for storing information for determining an update cycle of the high-speed playback screen, and the update cycle information storage means for arranging the high-speed playback data at a predetermined position on a recording medium. And a recording means for performing a predetermined recording signal processing on the high-speed reproduction data to record a recording signal on a recording medium.
The reproduction side has a reproduction signal processing means for obtaining a reproduction signal from the recording medium and performing a predetermined reproduction signal processing, and a high-speed reproduction image signal reconstructing means for reconstructing and outputting a high-speed reproduction image signal during high-speed reproduction. It is characterized by having.

According to a third aspect of the present invention, there is provided a digital television signal reproducing apparatus which reproduces a reproduction signal from a recording medium and performs a predetermined reproduction signal processing, and a high-speed reproduction image signal when reproducing at a high speed. The present invention is characterized by including high-speed reproduced image signal reconstructing means for constructing and outputting, and double speed recognizing means for recognizing double speed during reproduction.

[0008]

According to the digital television signal recording / reproducing apparatus of the present invention, the recording side generates high-speed reproduction data for outputting an image during high-speed reproduction, and optimizes the update cycle of the high-speed reproduction screen. The location of the high-speed playback data on the tape is determined and recorded according to the memory that stores the information, and the playback side reads the high-speed playback data recorded on the tape during high-speed playback, and Reconstruct to stream format and then output.

According to a third aspect of the present invention, there is provided a digital television signal reproducing apparatus which reads high-speed reproduction data recorded on a tape during high-speed reproduction, reconstructs it into a stream format at the time of input, and then outputs it. It is displayed in such a way that double speed of can be recognized.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, a digital VTR for recording and reproducing a digital broadcast coded by MPEG or the like as a digital signal on a magnetic tape will be described.

FIG. 1 shows a block diagram of a first embodiment of the recording apparatus of the present invention. In the digital television signal recording / reproducing apparatus of the present embodiment, 1 is a high-speed reproduction data generator, 2 is a formatter, 3 is an error correction encoder, 4
Is a modulator, 5 is a recording head, 6 is a magnetic tape, 7 is a reproducing head, 8 is a demodulator, 9 is an error correction decoder, 10 is a deformatter, 11 is a data reconstructor for high-speed reproduction, and 12 is a switch. , 21 is a system controller, and 22 is update period information, which is configured by these.

The input digital television signal is input to the formatter 2 and the high speed reproduction data generator 1. The data for normal playback that is output during normal playback is
Input data is recorded in the same data format. On the other hand, the input signal input to the high-speed reproduction data generator 1 generates high-speed reproduction data for outputting a screen whose recorded contents can be understood even during high-speed reproduction. In this case, first, the intra-coded screen data is extracted from the input signal, and the data amount is further compressed to extract only the low frequency component of the orthogonal transform coefficient when the recording capacity is increased. At the same time, the header part of the MPEG data stream is also extracted to generate high speed reproduction data and output to the formatter 2.

At the same time, the update cycle information 22 stores information for recording the high-speed reproduction data on the tape so that the reproduction screen at the time of high-speed reproduction is updated at the optimum time cycle. There is. For example, the update cycle information 22
Is information relating to the optimum recording position of the high-speed reproduction data on the tape for each double speed. Then, the information is output to the system controller 21. The system controller 21 outputs to the formatter 2 a control signal for arranging the high-speed reproduction data on the tape so that the update cycle is optimum for the set double speed. The formatter 2 converts the normal reproduction data and the high-speed reproduction data into recording packets for recording on the tape, and outputs the recording packets to the error correction encoder 3. At this time, the high-speed reproduction data is rearranged in response to the control signal from the system controller 21 so as to be arranged on the tape so as to have an optimum screen update cycle during high-speed reproduction. The signal error-correction coded by the error-correction encoder 3 is the modulator 4
Is output to The modulator 4 modulates a signal suitable for recording, and the recording head 5 records the signal on the magnetic tape 6.

Next, at the time of reproducing, the signal recorded on the magnetic tape 6 is read by the reproducing head 7, the reproduced signal is demodulated by the demodulator 8 and output to the error correction decoder 9. The error correction decoder 9 performs error correction and outputs it to the deformatter 10. The deformatter 10 restores the signal in the recording packet unit and divides it into normal reproduction data and high-speed reproduction data.
2. Data for high-speed reproduction is reconstructed for high-speed reproduction 1
Output to 1. The high-speed reproduction data reconstructor 11 converts the high-speed reproduction data into a data format that can be decoded by the MPEG decoder, and outputs the data to the switching unit 12. Switch 1
In No. 2, during normal reproduction, the terminal a and the terminal b are connected to output the normal reproduction data. During high speed reproduction, the terminals a and c are connected to output reconstructed high speed reproduction data.

Here, an example of arrangement of high-speed reproduction data on the tape will be described. On the recording side, special reproduction data is obtained by dividing a high-speed reproduction image output during high-speed reproduction into several super blocks for each screen. The super block includes a number of pixels, which is called a macro block in MPEG, corresponding to an amount that can be accommodated in the capacity of a recording packet which is a recording unit on the tape. When the bit length of each orthogonal transform coefficient is fixed and the number of macroblocks in the recording packet is fixed,
It is divided into i super blocks as shown in (a). In addition, when the bit length of each orthogonal transform coefficient is variable and the number of macroblocks in the recording packet is also variable,
It is divided into j super blocks as shown in (b). Assuming that the maximum speed set for this high-speed reproduction data area is N times speed, recording is repeatedly performed on (2 × N) tracks as shown in FIG. Here, high-speed reproduction data repeatedly recorded on (2 × N) tracks will be referred to as one segment. As a result, on the reproducing side, for example, in the case of two heads mounted on the rotary cylinder opposite to each other by 180 °, one segment of special reproduction data in the high-speed reproduction data area is reproduced as shown in FIG. It is possible to read complementarily. As a result, it is possible to obtain a high-speed playback image that is free from mixing, omission, and erroneous decoding even during special playback.

FIG. 4 shows the relationship between the double speed and the update period. By arranging the high-speed reproduction data as described above, the update cycle becomes shorter as the double speed becomes faster. Further, the relationship between the data rate and the double speed at this time is shown in FIG.
This time, conversely, the data rate increases as the double speed increases. This increase in the data rate means an increase in the rate of the special reproduction data, and the screen update cycle becomes shorter accordingly.

Next, a method of generating and recording a plurality of high-speed reproduction data and reading and outputting each high-speed reproduction data according to the double speed during high-speed reproduction will be described. Here, a case where two types of high-speed reproduction data for low-speed and high-speed reproduction are generated and recorded is taken as an example.

The relationship between the screen update cycle and the double speed at this time is shown in FIG.
Shown in As a result, the update cycle at a low double speed becomes shorter than when one type of high-speed reproduction data is used. Further, FIG. 7 shows the relationship between the data rate and the double speed at this time. This time, the data rate at high speed increases in two steps. FIG. 8 shows the data arrangement for high speed reproduction on the tape.

Further, high-speed reproduction data limited to each double speed tape is generated and recorded on the locus of the head, and data corresponding to the double speed is read during high speed reproduction. Here, the case where three types of high-speed reproduction data of low speed, medium speed, and high speed are generated and recorded is taken as an example. FIG. 9 shows the relationship between the data rate and the double speed at this time. This time the overall data rate will increase and data efficiency will improve.

In order to further shorten the update cycle at high speed, there is a method of lowering the resolution of reproduced image quality each time the speed increases. This utilizes the property that deterioration of resolution becomes less noticeable as the speed becomes faster. For example, at low speed, the DC component of the orthogonal transformation coefficient is set to the fifth to fifth data of the AC component, and at the medium speed, the data from the low component of the AC component to 2
Up to the first data, at high speed, only the DC component is used as high-speed reproduction data. FIG. 10 shows the data arrangement for high speed reproduction on the tape. However, the control is complicated because the head has to scan a fixed position on the tape during high-speed reproduction.

With the above configuration, the screen can be updated at a time cycle most suitable for the double speed during high-speed reproduction, and the update cycle becomes shorter as the double speed becomes faster. This makes the image easier to see, makes it easier to understand the recorded contents, and improves the search efficiency.

FIG. 11 is a block diagram of a digital signal reproducing apparatus according to the second embodiment of the present invention. In the digital television signal reproducing apparatus of the present embodiment, 6 is a magnetic tape, 7 is a reproducing head and 8 is a demodulator. , 9 is an error correction decoder, 10 is a deformatter, 11 is a high speed reproduction data reconstructor, 12 is a switch, 31 is a system controller, 32 is a speed data generator, and 33 is a switch. To be done.

First, the signal recorded on the magnetic tape 6 by a predetermined recording device is read by the reproducing head 7,
The demodulator 8 demodulates the reproduced signal and outputs it to the error correction decoder 9. The error correction decoder 9 performs error correction and outputs it to the deformatter 10. In the deformatter 10, the signal in the recording packet unit is restored to be divided into the normal reproduction data and the high speed reproduction data, and the normal reproduction signal is reconfigured to the switching unit 12, and the high speed reproduction data is reconstructed for the high speed reproduction. Output to the container 11. The high-speed reproduction data reconstructor 11 converts the high-speed reproduction data into a data format that can be decoded by the MPEG decoder, and outputs the data to the switching unit 12. From the system controller 31, a signal indicating the tape speed selected in the high speed reproduction mode is input to the speed indicator 32. The speed indicator 32 generates a signal indicating the ratio of the tape speed in the high speed reproduction mode to the speed during normal reproduction, and outputs the signal to the switch 33. The switching device 33 displays the double speed on the high-speed playback screen by turning the terminal on, and does not display it when it is turned off. The switch 12 outputs the normal reproduction data by connecting the terminal a and the terminal b during the normal reproduction. Also, at the time of high speed reproduction, by connecting the terminal a and the terminal c,
Output the reconstructed high-speed playback data.

Next, an example of displaying the double speed on the reproduction screen will be described. As a method of displaying, a method of indicating the double speed by a numeral as shown in FIG.
A method of displaying a meter as in (b), or FIG.
As shown in (c), there is a method in which the figure rotates in proportion to the double speed.

Next, an example in which the double speed is displayed on the VTR main body other than the screen will be described. For example, as shown in FIG.
Like the screen display on the display unit on the main body of R, a method of showing a double speed by a number, a method of displaying a meter, a method of rotating a figure in proportion to the double speed, or the like can be considered.

With the above configuration, the current double speed can be known at the time of high speed reproduction, and as auxiliary information of the high speed reproduction image,
The search effect can be enhanced.

Although the digital VTR has been described as an example in the description of this embodiment, the same effect can be obtained with another recording medium such as a disk.

Further, in the description of this embodiment, the output data at the time of reproduction is described by taking as an example the device which decodes the MPEG data stream and restores the image signal, but it is not a decoder as an input means but another device. Even when a circuit for outputting an MPEG data stream as a digital signal is provided, the same effect can be obtained by using the digital television signal recording / reproducing apparatus of the present invention.

Although the MPEG data stream has been described as an example in the description of this embodiment, a data stream compressed by another method can be recorded and reproduced by using the digital television signal recording / reproducing apparatus of the present invention. it can.

The arrangement method of the high-speed reproduction data on the tape in the digital television signal recording / reproducing apparatus of the present invention may be another arrangement method, and the head structure may be any structure.

Further, in the description of this embodiment, the example of the double speed in the forward direction has been described, but it goes without saying that the same effect can be obtained even with the double speed in the reverse direction.

Further, the means for displaying the double speed may be any display format, and the display place is on the screen and the VTR main body, but it may be on another external device.

[0033]

As described above, according to the digital television signal recording / reproducing apparatus of the present invention, the screen of the optimum update cycle is output according to the double speed at the time of high speed reproduction, so that the high speed reproduction image which is easy to see is displayed. Can be realized,
This makes it easy to understand the recorded contents and improves search efficiency.

Further, according to the digital television signal reproducing apparatus of the present invention, by displaying the double speed at the time of high speed reproduction, the double speed of the screen currently being output can be known, and the auxiliary information of the high speed reproduced image is searched. The effect can be enhanced.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment according to a digital television signal recording / reproducing apparatus of the present invention.

FIG. 2 is a diagram showing an example of a method for dividing one screen of a high-speed playback image.

FIG. 3 is a diagram showing an example of a track arrangement for repeatedly recording (2 × N) tracks of high-speed reproduction data.

FIG. 4 is a diagram showing a relationship between a double speed and an update cycle.

FIG. 5 is a diagram showing a relationship between a double speed and a data rate.

FIG. 6 is a diagram showing a relationship between a double speed and an update cycle when recording two kinds of high-speed reproduction data for low speed and high speed.

FIG. 7 is a diagram showing a relationship between a double speed and a data rate when recording two kinds of high speed reproduction data for low speed and high speed.

FIG. 8 is a diagram showing a track arrangement on a tape when two types of high-speed reproduction data for low speed and high speed are recorded.

FIG. 9 is a diagram showing a relationship between a double speed and a data rate when recording data for high speed reproduction on a head locus.

FIG. 10 is a diagram showing a track arrangement on a tape when high-speed reproduction data is recorded on a head locus.

FIG. 11 is a block diagram of a first embodiment according to the digital television signal reproducing device of the present invention.

FIG. 12 is a diagram showing a display example when double speed is displayed on a playback screen.

FIG. 13 is a diagram showing a display example when a double speed is displayed on a VTR main body.

FIG. 14 is a diagram showing a relationship between a double speed and an update cycle in a conventional example.

[Explanation of symbols]

 1 data generator for high speed reproduction 2 formatter 3 error correction encoder 4 modulator 5 recording head 6 magnetic tape 7 reproducing head 8 demodulator 9 error correction decoder 10 deformatter 11 high speed reproduction data reconstructor 12 switcher 21 system Controller 22 Update cycle information 31 System controller 32 Speed data generator 33 Switching device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H04N 7/24 (72) Inventor Nagashiro Yamamitsu 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. In the company

Claims (5)

[Claims] 1. A high-speed reproduction data generating means for generating a high-speed reproduction data for inputting a digital television signal and outputting an image during the high-speed reproduction from the digital television signal on a recording side, and a high-speed reproduction screen. Update cycle information storage means for storing information for determining the update cycle of, and control means for controlling the update cycle information storage means to arrange the high-speed reproduction data at a predetermined position on a recording medium, Recording means for performing a predetermined recording signal processing on the high-speed reproduction data to record the recording signal on a recording medium, and the reproducing side obtains a reproduction signal from the recording medium and performs a predetermined reproduction signal processing. A digital television comprising a processing means and a high speed reproduction image signal reconstructing means for reconstructing and outputting a high speed reproduction image signal during high speed reproduction. John signal recording / reproducing apparatus. 2. The digital television signal recording / reproducing apparatus according to claim 1, wherein the update cycle information storage means stores information for determining such that the update cycle of the high-speed playback screen becomes shorter as the double speed becomes faster. . 3. A reproduction signal processing means for obtaining a reproduction signal from a recording medium to perform a predetermined reproduction signal processing, and a high speed reproduction image signal reconstructing means for reconstructing and outputting a high speed reproduction image signal during high speed reproduction. A digital television signal reproducing apparatus comprising a double speed recognizing means for recognizing a double speed during reproduction. 4. A digital television signal reproducing apparatus, wherein the double speed recognizing means changes a part of a reproduction display screen so that the double speed can be recognized. 5. A digital television signal reproducing apparatus characterized in that the double speed recognizing means displays on the device so that the double speed can be recognized.