KR19990050081A - Reverse playback device for optical disc players - Google Patents

Abstract

The present invention is a reverse playback apparatus of an optical disc player for reversely reproducing a video signal stored in a unit of a GOP (Gropu Of Picture) composed of one reference picture and a plurality of prediction pictures on an optical disc, and reads the video signal from the optical disc. The program reading unit; A first storage unit sequentially storing the image signals read by the program reader and outputting the image signals in the reverse order of the stored order; A digital signal processor configured to demodulate and error correct the video signal output from the first storage unit; An MPEG decoder for decoding the video signal output from the digital signal processor; A second storage unit for sequentially storing the video signals output from the MPEG decoder and outputting them in the reverse order of the stored order; A display unit which displays an image signal output from the second storage unit as a predetermined image; In response to a reverse play key signal applied from the outside, the program reading unit is controlled to read the video signal recorded on the optical disc in a reverse direction and provide the first storage unit, and provide the decoded image data to the second storage unit. By providing a reverse playback apparatus for an optical disc player comprising a system control unit for controlling the MPEG decoder so that the predetermined video information recorded on the optical disc can be played in the reverse direction, the usability of the optical disc player can be improved.

Description

Reverse playback device for optical disc players

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc player, and more particularly, to an apparatus for reversing an optical disc player configured to reversely play predetermined video information recorded in GOP units on an optical disc.

In general, an optical disc player is a device that reads data from an optical disc on which several gigabytes (GB) of video and audio data are recorded, for example, by MPEG-2 moving picture compression technology. Compared to the playback device, it provides high quality and high sound quality, and provides useful functions such as random access, and is a widely used electronic device, including a compact disk player (CDP) and a laser disk player (LDP: laser disk). player and compact disk graphic player (CDGP), video compact disk player (VCDP), and digital video disk (DVD).

The above-described optical disc is used in the player to store a larger amount of data on an optical disc of limited data storage capacity, such as MPEG-1 using information compression techniques such as a hybrid encoding technique combining probabilistic encoding techniques and temporal and spatial compression techniques. MPEG-2 compression scheme is used.

In the above-described method of compressing data using MPEG-1 and MPEG-2, since the screen is constructed using the correlation with the neighboring screen, since the information on only one screen is not completely configured, the GOP The Group Of Pictures structure is used to group data for several prediction pictures (inter picture), including one reference picture (intra picture), which consists of information about one complete picture.

That is, referring to FIG. 1, which shows an example of an arrangement of picture types in a GOP, one GOP includes a picture of I picture including information about one complete picture, and a B / P including a prediction picture for an I picture. You can see it consists of 14 pictures.

Here, an I picture (Intra Picture) is an intra picture encoded with only one piece of picture information without using inter-frame prediction in order to secure independence of the GOP, and P picture (Predictive-Picture) and B picture (Bidirectionally Predictive). A picture) is an inter picture generated by performing prediction from an I picture that is an intra picture.

Therefore, in the optical disc player, when reading image information stored on the optical disc, the B / P picture is read out as a series of bit streams following the B / P picture based on the I picture, and the B / P picture based on the I picture is read from the read bit stream. The predetermined image corresponding to the image information was reproduced by stretching to one screen.

On the other hand, conventionally, since image information is applied in the order of I picture and B / P picture, normal playback in the forward direction is possible but reverse playback is not possible. That is, in reverse playback, since a B / P picture as a prediction picture is first applied and then an I picture as a reference picture is applied next, data of a full frame cannot be reproduced only by data for the B / P picture.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a reverse playback apparatus for an optical disc player configured to reproduce in a reverse direction after demodulating predetermined video information recorded in a GOP unit on an optical disc in a GOP unit. To provide.

In order to achieve the above object, according to the present invention, there is provided a reverse playback apparatus of an optical disc player for reversing a video signal stored in a unit of a GOP (Gropu Of Picture) consisting of one reference picture and a plurality of prediction pictures. A program reading unit which reads out an image signal from an optical disc; A first storage unit sequentially storing the image signals read by the program reader and outputting the image signals in the reverse order of the stored order; A digital signal processor configured to demodulate and error correct the video signal output from the first storage unit; An MPEG decoder for decoding the video signal output from the digital signal processor; A second storage unit for sequentially storing the video signals output from the MPEG decoder and outputting them in the reverse order of the stored order; A display unit which displays an image signal output from the second storage unit as a predetermined image; In response to a reverse play key signal applied from the outside, the program reading unit is controlled to read the video signal recorded on the optical disc in a reverse direction and provide the first storage unit, and provide the decoded image data to the second storage unit. An apparatus for reproducing an optical disc player comprising a system control unit for controlling an MPEG decoder so as to provide the same.

1 is an exemplary diagram illustrating an example of a screen type arrangement in a general GOP;

Fig. 2 is a block diagram showing a reproduction system of an optical disc player having a reverse playback device of an optical disc player according to the present invention.

<Description of the symbols for the main parts of the drawings>

100: key input unit 200: system control unit

300: program reading unit 400: digital signal processing unit

450: first storage unit 500: MPEG decoder

550: second storage unit 600: display unit

The above and other objects and advantages of the present invention will be apparent from the following description with reference to the accompanying FIG. 2.

Hereinafter, a configuration and an operation process of an apparatus for reverse playback of an optical disc player according to the present invention will be described in detail with reference to FIG. 2.

Fig. 2 is a block diagram showing a playback system of an optical disc player having a reverse playback device of an optical disc player according to the present invention.

Referring to FIG. 2, a reproduction system of an optical disc player having a reverse playback apparatus of an optical disc player according to the present invention includes a key input unit 100, a system control unit 200, a program reading unit 300, and a digital signal processing unit 400. In addition, the first storage unit 450, the MPEG decoder 500, the second storage unit 550, and the display unit 600 are included. The function of each component is as follows.

First, the key input unit 100 includes a plurality of function keys including a play key, a reverse play key, and the like, and generate and provide a key signal corresponding to a user's key operation to the system controller 200.

The system controller 200 controls the overall optical disc player 300 in response to an input signal applied from each of the constituent members of the key input unit 100 and the optical disc player 300, and in particular, the key input unit 100. When the reverse playback key signal is applied, the program reading unit 300 is read-controlled to reversely reproduce the video signal stored on the optical disc from the time when the key input unit is applied, and is applied upside down from the program reading unit 300. The program reading unit 3000 is output-controlled to provide an image signal to the first storage unit 450 in a GOP unit. In addition, when the reverse playback key signal is applied from the key input unit 100, the system decoder 200 receives an MPEG decoder. The MPEG decoder 500 outputs the control to provide the data decoded at 500 to the second storage unit 550.

The program reader 300 reads a predetermined video signal recorded on an optical disc in the forward or reverse direction under the control of the system controller 200, and reads the read video signal from the first storage 450 or the digital signal processor 400. To provide.

The first storage unit 450 is configured as a FIFO memory (First-In Last-Out Memory), and sequentially stores the image signals provided from the program reader 300, and stores the image signals corresponding to one GOP. When the storing is completed, the image signal stored in the reverse order provided from the program reading unit 3000 is provided to the digital signal processing unit 400.

The digital signal processing unit 400 controls the system control unit 200, and the original digital signal recorded on the optical disc through demodulation and error correction of the image signal provided from the program reading unit 300 or the first storage unit 450. After conversion to, the converted digital signal is provided to the MPEG decoder 500.

The MPEG decoder 500 decodes the digital signal provided from the digital signal processing unit 400 and provides the decoded digital signal to the display unit 600 or the second storage unit 550.

Like the first storage unit 450, the second storage unit 550 is composed of a FILO memory, and sequentially stores the image data decoded and provided by the MPEG decoder and then stores the stored image data in the reverse order. 600).

The display unit 600 reconstructs the decoded image data provided from the MPEG decoder 500 or the second storage unit 550 into an image signal of NTSC (National Television System Committee) or PAL (Phase Alternation by Line) scheme. The reconstructed video signal is converted into an analog video signal and displayed on a monitor (not shown).

Hereinafter, an operation process of an apparatus for reverse playback of an optical disc player according to the present invention, which is composed of the respective members for performing the above-described functions, will be described in detail with reference to FIG. 1.

If the user operates the reverse play key provided in the key input unit 100 to rescan the previously passed image in the play or stop state of the video signal recorded on the optical disc, the key input unit 100 performs the reverse play key of the user. A reverse playback key signal corresponding to the operation is generated, and the generated key signal is applied to the system control unit 200.

The system control unit 200 receiving the reverse play key signal from the key input unit 100 switches the playback system of the optical disc player to the reverse play mode.

That is, the program reading unit 300 is controlled to read the video signal recorded on the optical disk while rotating the optical disk in the reverse direction during normal playback, and to provide the read video signal to the first storage unit 450.

In addition, the MPEG decoder 500 may decode demodulated and error-corrected video signals provided from the digital signal processor 400 into original video data before compression encoding, and provide the decoded video signals to the second storage unit 550. ).

Under the control of the system control unit 200, the program reading unit 300 rotates the optical disc in the reverse direction of the rotation direction during normal playback, and performs a focus servo and a tracking servo corresponding thereto, and at a predetermined level on the signal surface of the optical disc. By irradiating a laser beam, the predetermined video signal recorded on the optical disc is read out.

In addition, the program reader 300 amplifies the read image signal, equalizes the amplified image signal to remove noise and distortion included in the image signal, and waveforms the waveform equalized image signal. After shaping and converting the rectangular pulse, the image signal converted into the rectangular pulse is provided to the first storage unit 450. In this case, since the image signal provided to the first storage unit 450 is reproduced in the reverse direction by the program reader 300, data about a prediction frame (B / P picture) is first provided to the image signal in a GOP unit. Finally, data will be provided for a reference frame (I picture) consisting of a complete picture.

On the other hand, the image signal provided from the program reader 300 is sequentially stored in the first storage unit 450, and when the image signal corresponding to one GOP is completed, the first storage unit 450 stores the stored image signal. Is provided to the digital signal processor 400 in the reverse order of the stored order. In this case, since the first storage unit 450 is composed of a FILO memory which outputs the data input first, the data for the I picture is first outputted as in the case of normal reproduction of the video signal recorded on the optical disc. Data for the B / P frame will be output sequentially.

Thereafter, since the video signals sequentially provided from the first storage unit 450 are modulated, the digital signal processor 400 demodulates the video signals sequentially provided from the first storage unit 450 into original image data. If the demodulated signal contains an error, the error is corrected and the demodulated and error corrected signal is provided to the MPEG decoder 500. In this case, the original image data is a signal obtained by converting an image signal applied in an analog form from the outside into a digital form by an A / D converter (not shown). The image is output from the digital signal processor 400. Will be the same as the data.

On the other hand, the MPEG decoder 500 is first applied with data for a reference frame consisting of data for one complete screen of image data demodulated and error-corrected by the digital signal processor 400, and then data for a prediction frame is sequentially applied. Since the MPEG decoder 500 is controlled by the system control unit 200, the MPEG decoder 500 decodes the data of the prediction frame into the image data of one complete screen before compression encoding by referring to the data of the reference frame. The decoded video data is sequentially provided to the second storage unit 550.

On the other hand, image data provided from the MPEG decoder 500 is sequentially stored in the second storage unit 550, and when the image data corresponding to one GOP is completed, the second storage unit 550 stores the stored image data. The display unit 600 is provided in the reverse order of the stored order. In this case, since the second storage unit 450 is composed of a FILO memory that outputs the first input image data last, the second storage unit 450 may perform the reverse playback of the video signal recorded on the optical disc.

That is, if the GOP unit included in the optical disc is composed of 1 I picture and 14 B / P pictures, and consists of 1 frame to 15 frames, the display unit 600 displays 15 frames → 14 frames → 13 times. Frame → ....... → Frame 2 → Frame 1 will be provided.

The display unit 600 reconstructs the image data provided from the second storage unit 550 into an NTSC or PAL image signal, converts the image data, which is a data signal, into an analog signal, and converts the converted signal into an analog signal. Display via a monitor (not shown).

According to the present invention described above, the predetermined video information recorded on the optical disc can be reproduced in the reverse direction, thereby improving the usability of the optical disc player.

Claims (1)

An apparatus for reversing an optical disc player for reversely reproducing a video signal stored in a unit of a GOP (Gropu Of Picture) consisting of one reference picture and a plurality of prediction pictures on an optical disc, A program reader for reading an image signal from the optical disc; A first storage unit sequentially storing the image signals read by the program reader and outputting the image signals in the reverse order of the stored order; A digital signal processor configured to demodulate and error correct the video signal output from the first storage unit; An MPEG decoder for decoding the video signal output from the digital signal processor; A second storage unit for sequentially storing the video signals output from the MPEG decoder and outputting them in the reverse order of the stored order; A display unit which displays an image signal output from the second storage unit as a predetermined image; In response to a reverse play key signal applied from the outside, the program reading unit is controlled to read the video signal recorded on the optical disc in a reverse direction and provide the first storage unit, and provide the decoded image data to the second storage unit. And a system controller for controlling the MPEG decoder so as to control the MPEG decoder.