KR100266371B1 - High speed reproduction method and data structure therefor - Google Patents

Abstract

PURPOSE: Data structure of a DVD(Digital Video Disk) is provided to obtain regular temporal resolution in fast reproducing and to supply high definition of screen to a consumer. CONSTITUTION: An optical pickup(25) reads data out of a disk(15) having audio, caption and video data. An analog signal processor(35) compensates the reproducing data of the optical pickup and outputs the data through analog signal processing including filtering. A digital signal processor(45) outputs reproducing control signals of video, audio and caption data after digital signal processing of demodulation and forward error correction. An audio/video signal decoder(55) outputs reproducing signals for a TV by decoding the video, audio and caption data from the digital signal processor. A microcontroller(65) controls the optical pickup, the analog signal processor, the digital signal processor and the audio/video signal decoder. Therefore, the data structure of a DVD obtains regular temporal resolution in fast playback.

Description

High speed playback device, method and data structure

The present invention relates to a high speed playback apparatus, a method and a data structure thereof, and more particularly, to a high speed playback apparatus, a method and a data structure thereof capable of providing a viewer with high image quality at high speed playback.

Until now, recording media for storing image data include a video tape of a magnetic recording method, a laser disk as an optical disk, and a video CD (compact disk). Among them, the most common at this stage is video tape. This is because the video tape has more storage capacity than the other recording media, so that the video tape has sufficient storage capacity. However, since video tape uses an analog recording method, recording capacity per unit area is small, and analog recording method has a disadvantage in that image quality is poor during repeated playback, and storage problems are many.

Laser disks are relatively widely used as optical disks, but because they use an analog recording method, the size of the disk having a diameter of 30 centimeters and the amount of information storage of the cross section are only one hour. In addition, video CD has a small size of 12 centimeters in diameter and uses a digital recording method, but has a problem in terms of capacity because the information storage amount is only about 74 minutes.

Therefore, users want a recording medium that has enough storage capacity to play about two hours of movies without sacrificing image quality even after repeated playback, and according to this demand, the recording medium appeared as a digital video disc (DVD). Is called).

A DVD has a size of 12 centimeters in diameter, similar to a video CD, and has a recording capacity of about 5 gigabytes (5G bytes: about 135 minutes of video data reproduction), and employs a digital recording method. Therefore, many industries are calling DVD as the next generation information storage medium and watching the development, and especially in the video industry, the situation is directly involved in the development of DVD.

Therefore, DVD allows various angle screen data to be saved, 8 audio, 32 language subtitles, and a plurality of programs can be selected for selection. system specifications such as parental lock).

A DVD having such a system specification will be sold or rented to a consumer by storing image data, such as a movie or a music video, that has been performed on a previous videotape. After purchasing or renting a DVD containing a desired program, consumers can watch the desired program by mounting and playing the DVD in the DVD player.

By the way, conventional audio / video equipment such as a video cassette recorder has a high speed playback function. The high speed playback function is a function of playing a disc faster than the normal speed (1x speed) when the consumer wants to find a desired screen or when the user wants to watch the playback speed faster.

Accordingly, the DVD player has to be able to reproduce data recorded on a DVD as well as a high speed playback function for consumers who are familiar with audio / video equipment such as a conventional video cassette recorder. Moreover, the high speed playback function is more necessary in a recording medium having a plurality of programs and the like due to various system specifications such as DVD.

Next, a high speed playback method supported by a conventional DVD player will be described with reference to the accompanying drawings.

Fig. 1 is a block diagram showing the structure of a conventional DVD player, and Fig. 2 is a data structure diagram of a DVD for supporting high speed reproduction.

Conventional DVD playback apparatuses include a disk 10 storing audio, subtitle and video data, an optical pickup device 20 for reading data from the disk 10, and the optical pickup device 20. And an analog signal processing device 30 for compensating for the reproduction data read from the digital signal and for digitizing and outputting an analog signal such as filtering. In addition, the analog signal processing device 30 analyzes the analog signal applied from the optical pickup device 20, and adjusts the optical pickup device 20 to read an accurate optical signal from the disk 10. Perform.

The DVD player inputs a digital signal output from the analog signal processing device 30, performs digital signal processing such as a demodulation operation and a forward error corrention, and then executes a video and audio signal. And a digital signal processing device 40 for extracting and outputting a sub picture and a reproduction control signal.

The DVD player includes an audio / video signal decoder 50 that decodes video, audio, and sub picture data input from the digital signal processing device 40 to generate a signal that can be reproduced on an actual television.

In addition, the DVD playback apparatus controls the optical pickup apparatus 2, the analog signal processing apparatus 30, the digital signal processing apparatus 40, and the audio / video signal decoder 50 to operate normally according to the playback control signal. It includes a microcontroller 60. In the above configuration, the optical pickup device 20, the analog signal processing device 30, and the digital signal processing device 40 have the capability of processing only data input at a normal speed (1x speed).

That is, in the conventional DVD playback apparatus, data is played back at 1x speed, and when high speed playback is required, only part of the picture data is reproduced in a group of picture (GOP) stored on the disc 10.

2 is a data structure diagram of a DVD for supporting conventional high speed playback.

In the illustrated data structure, each data is recorded in units of a continuous Video Object Unit (geometric VOBU), and reproduction is also adjusted in units of the VOBU.

Each VOBU includes PCI (Presentation Control Iuformation), data detection information (hereinafter referred to as DSI), a group of pictures (hereinafter referred to as GOP), voice data, and sub picture data. In the description of the present invention, however, only the DSI and the GOP used in the high-speed playback are selected and shown, and each VOBU is assumed to be composed of only one GOP.

Each GOP is composed of 15 picture frames including an I-picture (I), a P-picture (P), and a B-picture (B) (DI = 15), and I- within the GOP. The distance between the picture and the P-picture or the distance between the P-picture and the P-picture is generally three images (DP = 3).

Here, briefly looking at each picture, I-picture means an intra picture (Intra Picture). An I-picture is a picture having image information capable of representing a single picture independently of the preceding and subsequent pictures, and its code allocation is about 40 kilobytes.

P-picture (Predictive Picture) means image information containing a forward predictive coded picture of the I-picture. The P-picture cannot constitute an image by itself, but is image information that can represent a changed image after the I-picture in combination with the image information of the I-picture. The code quota for P-pictures is about 10 kilobytes.

A B-picture (Bidrectionally predictive Picture) means image information containing a bidirectional predictive coded picture. Like a P-picture, a B-picture cannot compose an image by itself, and can be combined with a previous I-picture and a subsequent P-picture, thereby displaying image information between an I-picture and a P-picture. to be. The code allocation of such a B-picture is about 5 kilobytes.

As shown in Fig. 2, each DSI includes three pieces of video recording position information P1, P2, and P3.

P1 represents the end address at which the first I-picture was recorded, P2 represents the last position at which the first P-picture or the second I-picture was recorded, and P3 is the I-picture or P immediately following P2. Indicates the final position at which the picture was recorded.

Next, a description will be given of the process of the playback in the conventional DVD player.

The servo unit (not shown) controls the rotational speed of the disk 10 at 1x speed under the control of the microcontroller 60 at the time of data reproduction at the normal speed. The optical pickup device 20 is moved to the position of VOBU1 to be reproduced under the control of the servo unit (not shown), and sequentially reads all 15 picture data included in each GOP1 of VOBU1 currently located and converts it into an electrical signal. And print it out.

At this time, the read I, P, B picture data is output from the analog signal processing device 30 to the digital signal processing device 40 after analog signal processing such as signal compensation and filtering, and the digital signal processing device 40 is The input I, P, and B picture data are digitized such as demodulation and error correction and output. The digital signal is input to the audio / video decoder 50, separated into video, audio, subtitle data, and the like, and then decoded. The output data of the audio / video decoder 50 is displayed after being encoded to be displayed on a display device such as a television or a monitor.

The encoding light guide forms a first frame from image information of an I picture included in GOP1 of each VOBU1. Then, the fourth frame is formed by combining the image information of the first P picture with the image information of the first frame, and the second frame is formed by combining the image information of the first B picture and the image information of the first B picture. do. The third frame is formed by combining the second frame image information with the image information of the second B picture. The frames continuously constructed also synthesize the frames while accumulating and adding one piece of picture image information.

Therefore, in 1x playback, 15 frames can be configured for each VOBU composed of 15 video pictures.

That is, in 1x reproduction, decoding is performed in which all I, P, and B pictures of the GOP included in the respective VOBUs are read from the optical pickup device 20. Then the process of encoding into a frame output to a television or monitor is performed. The encoded frames are temporarily stored in a storage means such as a buffer, and each frame is sequentially displayed in 1/30 second units. Thus, the user has a visual effect of watching the video.

The following describes the video data reproduction method when the double speed reproduction is performed.

The microcontroller 60 recognizes the double-speed playback request of the disk by external key input, controls the servo unit (not shown), and controls the rotation speed of the disk 10 to be faster than the normal speed. The servo unit (not shown) receives the movement position information of the optical pickup device 20 from the microcontroller 60 and controls the position of the optical pickup device 20.

The optical pickup device 20 reproduces seven picture data included from the I-picture located at the beginning of the GOP1 to the position of P3 among the pictures included in the GOP1 in the VOBU1. That is, the optical pickup device 20 reproduces the first I-picture, two P-pictures, and four B-pictures. At this time, each picture up to the position of P3 read by the optical pickup device 2 is input to the digital signal processing device 40 after demodulating and error after the signal compensation and filtering process is performed in the analog signal processing device 30. Digital signal processing such as correction is performed.

Then, it is input from the audio / video signal decoder 50, separated into video, audio, subtitle data, and the like, and decoded and output. The output data is encoded and displayed on a display device such as a television or a monitor and then displayed.

On the other hand, while the frame synthesized by the seven pictures of the first VOBU1 (pictures up to the position of P3) is displayed, the microcontroller 60 controls the servo unit (not shown) to display the optical pickup device 20. Control for moving to the track on which the second VOBU2 is recorded. Therefore, during double-speed playback, video data between the position after P3 in GOP1 of VOBU1 and the start position in GOP2 of next VOBU2 is skipped. That is, all P pictures and B pictures after the second P-picture are discarded.

Then, the optical pickup device 20 reads the DSI information which is the data search information of VOBU2, and based on the DSI information, the microprocessor 60 causes the optical pickup device 20 to start in the GOP of the second VOBU2. Control to read picture data from the I picture at the position to the position of P3. Signal processing of the read picture data is performed in the same manner as the above-mentioned process.

In other words, the conventional double-speed high-speed playback method reproduces seven pictures from the first picture among the 15 picture data of each GOP, and discards eight picture data between the position after P3 in the GOP and the start position of the next VOBU. As a result, playback at 15 / 7x speed is achieved. Therefore, the conventional double speed high speed reproducing method is not accurate double speed, but there is a problem that 15/7 times reproduction is performed as compared with the normal regeneration by 1x speed.

Moreover, in the case of the conventional double speed reproduction, there is a problem that the resolution in the time axis direction is nonuniform. In the case of a general video, 30 frames per second are provided. In the case of the conventional double-speed playback, up to P3 of the GOP of every VOBU is sampled at 1/30 second intervals. As all pictures are deleted after P3 in the GOP and before the first I-picture of the next GOP, the interval is widened to 1/4 second until the I-picture of the next GOP is sampled.

Therefore, in the conventional double-speed playback picture, the sampled picture is reproduced at 1/30 second intervals from the first frame to the seventh frame, but the sampled picture is reproduced at 1/4 second intervals in eight frames. . This phenomenon is called jekiness, and when the sampling interval is changed as described above, the user feels that the movement of the screen unnaturally runs, resulting in image quality deterioration.

The following describes the 4X playback process by the conventional high speed playback method. Since the signal processing process of the configuration shown in FIG. 1 according to each speed will be omitted in the same manner as the previous process, and will be described in detail with respect to which picture is reproduced at each speed with reference to FIG. 2. do.

In 4X playback, I-pictures, P-pictures, and B-pictures up to P2 are played back for all VOBU GOPs. That is, in each GOP, only an I-picture, two B-pictures, and one P-picture are reproduced. In other words, reproduction of up to four pictures is performed at the position of the I-picture which is the start picture among the fifteen pictures.

The decoded four picture data is decoded in the decoder 50 and then encoded into a displayable signal. In this case, the encoding process forms a first frame from the image information of the I picture, combines the image information of the first P picture with the image information of the first frame, and forms a fourth frame, and the image information of the fourth frame. The second frame is formed by combining the image information of the first B picture. The frame synthesis process for each VOBU is completed by combining the second frame image information with the image information of the second B picture to form a third frame. That is, each VOBU is displayed on the display by combining only four frames. Therefore, the actual playback speed in 4x speed playback is not a precise 4x speed, but a high speed playback system having a speed of 15/4 times.

Also in 4x playback, as in the case of 2x playback, sampled images are played back at intervals of 1/30 sec. Up to 4 frames, but between 4 and 5 frames and between 8 and 9 frames, 12 and 13 frames. Sampling interval of must be different from 1/30 seconds, after all, such a high-speed playback method of the prior art caused a deterioration of image quality.

The conventional high speed playback method described above has a problem of causing image quality deterioration such as jekyness phenomena due to the problem that the temporal resolution of the image is uneven. This deterioration of image quality is further exacerbated in the case of a data format in which multiple GOPs are included in one VOBU.

In addition, the conventional high speed playback method also has the disadvantage that the correct speed playback is not made. In other words, it is impossible to achieve accurate 2x and 4x speeds, because the 2x speed is 15 / 7x speed, and the 4x speed is reproduced at 15 / 4x speed.

It is therefore an object of the present invention to provide a high speed playback apparatus, a method and a data structure thereof capable of making the resolution in the time axis direction uniform during high speed playback.

Another object of the present invention is to provide a high speed playback apparatus, a method and a data structure thereof capable of supplying a high quality screen to a consumer using the proposed data structure.

1 is a block diagram showing the structure of a conventional DVD player.

2 is a data structure diagram of a DVD for supporting conventional high speed playback.

3 is a block diagram showing the structure of a DVD player for high speed playback according to the present invention;

4 is a structural diagram of the speed speed controller shown in FIG.

5 is a data structure diagram recorded on a general disc.

6 is an illustration of a fast playback method according to the present invention.

7 is a first embodiment of a data structure for fast reproduction according to the present invention.

8 is a second embodiment of a data structure for fast reproduction according to the present invention.

A high speed reproducing apparatus according to the present invention for achieving the above object comprises: reading means for reading I-picture, P-picture, and B-picture data from a recording medium; Data selecting means for selecting data of a desired component from the picture data read out from the reading means; And control means for controlling the data output means in the required double speed reproduction.

A high speed reproduction method according to the present invention for achieving the above object is a reproduction method of a frame formed by the combination of I-picture, P-picture, B-picture; At normal speed, all pictures are reproduced to output N frames per unit time; Outputting n frames per unit time by reproducing the I-picture and the P-picture or reproducing only the I-picture when N times speed; In the case of N / 2 times, N / 2 frames are output per unit time by reproducing I-picture and P-picture or reproducing only I-picture.

In addition, according to the high-speed playback method of the present invention, in the image data forming a frame by a combination of I-picture, P-picture, and B-picture, each picture is composed of a plurality of pack data having a predetermined size. In the data structure having the header information for the data and the user data consisting of one piece of picture data or two pieces of contiguous picture data, in the case of double speed playback, it is determined which component data is from the header information, It is characterized by reproducing only data.

In addition, according to the high-speed playback method of the present invention, in the image data forming a frame by a combination of I-picture, P-picture, and B-picture, each picture is composed of a plurality of pack data having a predetermined size. The data is a data structure having header information about data and user data consisting of one piece of picture data or two pieces of picture data that are contiguous, where the preceding picture and padding data are included when the contiguous picture data includes a B-picture. And the user data, and in the case of double speed playback, it is judged which component data is from the header information, and reproduces only the data of the desired component.

The data structure according to the present invention for achieving the above object is, in the image data forming a frame with a combination of I-picture, P-picture, B-picture, each picture is composed of a plurality of pack data having a predetermined size In addition, the pack data is characterized by having the hair information on the data and the user data consisting of one picture data or two picture data consecutively.

Further, in the data structure of the present invention, in the image data forming a frame with a combination of an I-picture, a P-picture, and a B-picture, each picture consists of a plurality of pack data having a predetermined size. In a data structure having header information about data and user data consisting of one piece of picture data or two pieces of picture data contiguous, when the continuous picture data includes a B-picture, only the preceding picture contains user data. It is characterized by the configuration.

DETAILED DESCRIPTION Hereinafter, a high speed reproducing apparatus, a method, and a data structure thereof according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a block diagram showing the configuration of a DVD player for high speed playback according to the present invention.

The DVD player apparatus according to the present invention includes a disc 15 storing audio, subtitle and video data, an optical pickup device 25 for reading data from the disc 15, and the optical pickup device 25. And an analog signal processing device (35) for signal compensation of the reproduction data read from the digital signal, and for outputting the analog signal processing such as filtering. In addition, the analog signal processing device 35 analyzes an analog signal applied from the optical pickup device 25 and controls the optical pickup device 25 to read an accurate optical signal from the disk 15. Perform.

The DVD player of the present invention inputs an output signal from the analog signal processor 35, performs digital signal processing such as a demodulation operation and a forward error corrention, and then outputs an image, And a digital signal processing device 45 for extracting and outputting a reproduction control signal of audio and sub picture. In addition, the DVD player of the present invention includes an audio / video signal decoder 55 for decoding a video, audio, and sub picture data input from the digital signal processor 45 to generate a signal that can be reproduced on an actual television. .

In addition, the DVD playback apparatus of the present invention allows the optical pickup apparatus 25, the analog signal processing apparatus 35, the digital signal processing apparatus 45, and the audio / video signal decoder 55 to operate normally in accordance with the playback control signal. It includes a microcontroller 65 for controlling so that.

The DVD player of the present invention is located between the digital signal processor 45 and the audio / video signal decoder 55, inputs the pack data supplied from the digital signal processor 45, and the microcontroller 65 And a speed controller 75 for controlling the double speed mode on the basis of the double speed mode information from ") and the double speed flag information from the sector head field.

Each of the components included in the DVD playback apparatus of the present invention is characterized in that the data inputted from the disk 15 at N-speed can be processed normally. Therefore, in the present invention, the components having the above functions can only process data input at the normal speed (1x speed), but in the present invention, these components can normally process the data input at the Nx speed from the disk. Difference appears.

4 is a simplified block diagram of the function of the speed controller 75 according to the input / output signal.

Next, a DVD playback method for high speed playback according to the present invention will be described in detail with reference to the accompanying drawings.

5 shows a general data format recorded on the disc.

The data structure recorded on a general DVD has a sector unit as shown in FIG. Therefore, the optical pickup apparatus reads data from the disk 15 in sector units and transfers the read data to the signal processing apparatus. The sector input to each signal processing device is signal processed in units required by each signal processing device, for example, a sector or a plurality of sectors.

The sector includes header data and user data, which are management information, and user data includes data that a user wants to reproduce, such as a video, audio, and a sub-screen. Therefore, the pack data described in the present invention is used in the same sense as a sector used in a general disc data recording format. The I, P, and B pictures described in the present invention are composed of a plurality of pack data as shown in Figs. Each pack data includes header information and user data having double speed flag information according to the type of pack.

6 is an exemplary view for explaining a fast playback method proposed in the present invention.

In the configuration illustrated in FIG. 6, as in the conventional case, the GOP of each VOBU is composed of 15 pictures, and the distance between the I-picture and the P-picture included in each GOP or between the P-picture and the P-picture. The distance of is represented by three pictures (DP = 3).

First, the case of normal speed, i.e., 1x speed reproduction will be described.

The optical pickup device (2%) is moved to the position of the VOBU to be reproduced under the control of the servo unit (not shown), sequentially reads all 15 picture data included in the GOP of the VOBU currently located, and converts it into an electrical signal. Output

At this time, the read I, P, B picture data is output from the analog signal processing device 35 to the digital signal processing device 45 after analog signal processing such as signal compensation and filtering, and the digital signal processing device 45 is The input I, P, and B picture data are digitized such as demodulation and error correction and output.

The digital signal is input to the speed controller 75, and the speed controller 75 passes all of the input I, P, and B data unconditionally. Therefore, in the case of 1x speed, the microcontroller 65 does not perform special control for the data output control of the speed controller 75, and only outputs all the input data.

Therefore, the output data of the speed controller 75 is input to the audio / video decoder 50, separated into video, audio, subtitle data, and the like, and then decoded. The output data of the audio / video decoder 55 is encoded in order of being inputted so as to be displayed on a display device such as a television or a monitor, and then one image is displayed every 1/30 seconds. An output form of 1x speed shown in FIG. 6 represents image data output from the speed controller 75.

The following describes a high speed playback method according to 3 times speed.

When the user selects the triple speed playback by an external key input, the microcontroller 65 recognizes the triple speed playback request and performs control according to triple speed playback in each circuit section. The microcontroller 65 applies the triple speed mode to the speed controller 75. In this way, when controlled at 3x speed, the speed controller 75 checks the speed flag of the input picture data according to the speed mode applied by the microcontroller 65, and outputs only I picture and P picture as output terminals, and B. The picture data is set to be discarded.

In this manner, after the signal processing according to the user's selected speed mode is performed, the optical pickup device 25 reads the picture data from the disk 15 that is rotated at three times the speed. The picture data read from the optical pickup device 25 is applied to the analog signal processing device 35 and the digital signal processing device 45 to perform signal processing.

At this time, the analog signal processing device 35 and the digital signal processing device 45 are controlled to perform data processing at a triple speed under the control of the microcontroller 65, and the speed control by the high speed reproducing is a signal of the input data. By adjusting the reference clock signal for processing, signal processing at a desired speed may be achieved.

Each picture data decoded at three times the speed of the digital signal processor 45 is input to the speed controller 75. The speed controller 75 checks the double speed flag of the picture data input by the triple speed mode applied by the microcontroller 65, and outputs data when the input data is an I picture and a P picture, and then decodes the decoder 55. ), And the input data is discarded when the input data is B-picture data. Therefore, the data input to the decoder 55 consists only of I-picture data and P-picture data, and the decoder 55 decodes the two types of picture data and then displays each image every 1/30 second. Play on

Therefore, the 3x speed output form shown in FIG. 6 shows picture data output from the speed controller 75. FIG. That is, the I picture located at the beginning of the GOP and the P picture data located at the fourth, seventh, tenth, and thirteenth positions are reproduced. Then, the optical pickup device 25 is moved to the position of the next GOP, indicating that the I picture and the P picture located in the above order are reproduced.

That is, according to the triple-speed reproduction of the present invention, I and P picture data located at three video intervals are reproduced among 15 pictures included in the GOP of each VOBU. Therefore, in the case of 3x reproduction, the I picture and the P picture are reproduced at regular intervals by three image intervals, and the reproduced data becomes five images among 15 image data. That is, the accurate three times speed by 15/5 times speed can be achieved.

The following describes the operation at 1.5 times the speed of the present invention.

The operation of the fast playback which will be described later will be described with reference to FIG. 6, and the operation of the player that performs the fast playback is the same as the above process and thus will be omitted.

At 1.5 times speed, only I and P pictures are reproduced and decoded as in the above 3 times speed, and then each frame is repeatedly displayed twice. In this case, picture data at positions 1, 4, 7, 7, 10, and 13 are reproduced to form a frame signal in each GOP, but since the configured frame is displayed twice, the image of twice the speed is displayed. Therefore, the screen is newly converted once every 1/20.

Next, the 15 times speed operation of this invention is demonstrated.

For the 15x speed and 7.5x speed to be described later of the present invention, the microcontroller 65 does not control the selection operation of the picture data to be output by the roasting flag of the pack data input to the speed controller 75, but each VOBU. Picture data to be output is recognized by the DSI information included in the.

Since the operation of the player is also performed at a high speed of 15 times, it is not possible to individually check the header information for all input pack data, and in the 15 times playback of the present invention, the reference frame is used for the GOP of each VOBU. This is because only I pictures that form a signal are reproduced.

That is, the 15x reproduction reproduces the position P1 of the I picture from the DSI information of each VOBU in the microcontroller 65, moves the optical pickup device 25 to that position, and then reads out the I picture. The read I picture data is input to the speed controller 75 after the predetermined signal processing in the signal processing apparatus, and the speed controller 75 outputs the input I picture under the control of the microcontroller 65. At this time, the P picture or the B picture reproduced together during the reproduction of the I picture is discarded by the speed controller 75 under the control of the microcontroller 65.

Therefore, the output speed of 15 times shown in FIG. 6 indicates that only one I picture is reproduced among the 15 image data included in the GOP of each VOBU. The I pictures output from the speed controller 75 are displayed after being decoded by the decoder 55. Therefore, by reproducing 15/1 image data, the image is reproduced at a high speed of accurate 15x speed. (B-pack) is unconditionally passed (bvpass). Therefore, all necessary images can be reproduced at normal speed (i.e., 1x speed).

For 1.5x and 3x speeds, the speed controller operates according to the double speed flag value, selectively passing only packs containing I-picture and P-picture components. Therefore, in this double speed mode, the data of the B-pack is not passed, and image information is synthesized using only the I-picture and the P-picture.

For 7.5x and 15x speeds, the speed controller does not respond to the value of the double speed flag, only the DSI information. Thus, as in Table 1, only packs containing I-picture components in each GOP are selectively passed.

In the high speed reproduction operation of the present invention described above, in the case of the 1.5x and 3x speeds, only the I picture and the P picture are reproduced by removing all the B pictures, and the picture data sampling interval at this time is always a constant 3 picture. As a result, the sampling interval in the time axis direction is always constant.

In the case of 7.5x and 15x speeds of the present invention, since only the I picture is reproduced by removing both the P picture and the B picture, the output image is always sampled at 14 intervals at all times. Thus, the sampling interval in the time axis direction is always constant.

For the above-described double speed playback, when the specific gravity of the B picture among the I, P, and B pictures included in any GOP is R%, the following value should be given for the corresponding GOP.

The following describes the high speed reproduction operation at 7.5 times speed.

The 7.5x reproduction of the present invention is performed in such a manner that only the I picture is reproduced or is repeatedly displayed twice on the screen as in the case of the previous 15x. As a result, the screen will refresh once every 1/4 second. That is, the 7.5x output state shown in FIG. 6 indicates that the I picture of the first GOP is reproduced twice, and the I picture of the next GOP is reproduced twice.

Next, Table 1 shown below summarizes the functions of the speed controller 75 shown in Fig. 4 and shows picture data reproduced in any high speed reproduction according to the present invention.

Table 1-Function summary of the speed controller. DI = 15, DP = 3

That is, the speed controller 75 inputs the double speed mode signal K and the double speed flag value as a function selection input to selectively output data among the output data of the digital signal processing apparatus 45.

In the case of 1x speed, the speed controller 75 passes all input pack data (I-pack, P-pack, B-pack) unconditionally (bvpass). Therefore, all necessary images can be reproduced at normal speed (i.e., 1x speed).

For 1.5x and 3x speeds, the speed controller operates according to the double speed flag value, selectively passing only packs containing I-picture and P-picture components. Therefore, in this double speed mode, the data of the B-pack is not passed, and image information is synthesized using only the I-picture and the P-picture.

For 7.5x and 15x speeds, the speed controller does not respond to the value of the double speed flag, only the DSI information. Thus, as in Table 1, only packs containing I-picture components in each GOP are selectively passed.

In the high speed reproduction operation of the present invention described above, in the case of 1.5x speed and 3x speed, only I picture and P picture are reproduced by removing both B pictures, and the picture data sampling interval at this time is always a constant 3 picture. As a result, the sampling interval in the time axis direction is always constant.

In the case of 7.5x and 15x speeds of the present invention, since only the P picture and the B picture are removed and only the I picture is reproduced, the output image is always sampled at 14 intervals. Thus, the sampling interval in the time axis direction is always constant.

For the above-described double speed playback, when the specific gravity of the B picture among the I, P, and B pictures included in any GOP is R%, the following value should be given for the corresponding GOP.

N (the number of picture data included in the GOP) ≥ [100 / R]

Where [X] is the value of X rounded up. For the whole disk, the maximum value among N of each GOP should be used. Therefore, high quality high-speed playback will be possible when N≥3 for most video data.

Next, Fig. 7 shows a data structure after packing the encoded picture data suitable for recording on a disc.

The encoded picture data is divided into a plurality of packs of 2048 bytes and recorded on a disc. As shown, a pure pack (I pack, P pack, and B pack) containing only one image component and two image components Mixed hybrid packs exist (IP packs, PB packs, BP packs, BI packs).

Therefore, Table 2 summarizes the packs that are played in connection with the fast playback in the case of using the pack format shown in FIG.

When the speed flag is used in the speed controller 75, it is the case of 1.5 times speed and 3 times speed. As shown in Table 1, the speed controller 75 blocks the packs including the B-picture in the case of 1.5x or 3x speed.

Table 2-Summary of functions during fast playback for pack format of FIG.

Thus, packs (I pack, P pack, I-P pack) that do not contain a B-picture have the same double speed flag value (00) as shown in Table 2. On the other hand, the pack (B pack) including only the B-picture also has an independent flag value (11). In addition, among the mixed packs, the independent flag value (01) is also applied to the mixed pack (BP pack, BI pack) and the remaining mixed pack (PB pack) mixed with B-picture immediately following P-picture or I-picture data. And 10).

Each operation according to the double speed flag value is as follows.

When a pack with a flag value of 00 is input to the speed controller 75, data is unconditionally transmitted at 1.5 times and 3 times speed.

When a pack having a flag value 01 is input, the speed controller 75 transmits the input pack data, and the audio / video signal decoder E inputting the transmitted data is an I-picture header or a P-. The data until the picture header is found is deleted, and only data after the I and P picture headers are detected.

When a pack having a flag value of 10 is input, the speed controller 75 transmits the input pack data, and the audio / video signal decoder E that inputs the transmitted data finds a B-picture header among the pad data. Deletes the data afterwards.

When a pack with a flag value of 11 is input, data transmission is prohibited in the 1.5x or 3x mode.

Such a high-speed control method is superior to the pack format as shown in FIG. 8 to be described later, but the data recording efficiency is excellent, but there are disadvantages in supporting various functions according to the pack type.

Since the use of the double speed flag is unnecessary at 7.5 times and 15 times speed of the present invention, description thereof is omitted.

Next, high-speed playback of the packed format as in FIG. 8 will be described.

FIG. 8 illustrates a packing method in which all packs in contact with the B picture are configured only with pure packs when the image data is packed.

As shown in FIG. 8, there is a case where a full-pack of 2048 bytes cannot be formed with only one image component in a portion where a B picture and a P picture contact each other, and an area where the B picture and I picture contact each other as shown in FIG. .

Such packs are classified as incomplete packs in FIG. The pack shown in Fig. (B) represents a complete pack that forms a 2048 byte pack with only one image component. The incomplete pack is configured as a complete pack after filling the padding packet as shown in (c), the padding packet data is automatically deleted from the A / V decoder.

Therefore, according to the packing method of FIG. 8, the B picture is not mixed with other types of image components to form a pack. However, the I picture and the B picture may form a pack by mixing two image components. This is because high-speed reproduction is performed by the double speed flag only in the case of 1.5 times and 3 times speed, and only the B-picture is deleted.

Table 3 summarizes the matters related to the fast playback in the case of using the pack format as shown in FIG.

According to the packing method shown in FIG. 8, since a B-picture constitutes a pure pack independently of other types of image components, there is no pack of a type that impedes high-speed playback such as a BP pack, a BI pack, and a PB pack. .

Therefore, as shown in Table 3, it is divided into a pack containing pure B-picture, other pure packs (I, P packs), and mixed packs (packs of mixed I, P).

Table 3-Summary of Functions at High Speed for the Pack Format of Figure 4

At this time, the operation according to each double speed flag value is as follows.

The speed controller 75 causes data to be unconditionally transmitted in the case of 1.5 times speed and 3 times speed when a pack having a speed flag value of 0 is input. When the pack with the flag value 1 is input, the speed controller 75 is prohibited from transmitting data in the 1.5x and 3x modes.

This method is disadvantageous in that the data recording efficiency is lower than that in the pack format as shown in FIG. 3 described above, whereas the adjustment according to the pack type is simple.

As described above, the DVD data structure according to the present invention can eliminate the resolution imbalance in the time axis direction generated at the time of high-speed playback, thereby making it possible to feel the screen configuration naturally and to prevent the deterioration phenomenon.

In addition, the DVD data reproducing apparatus according to the present invention includes a high speed processing function other than the standard functions suggested by the current DVD reproducing apparatus as an extension function, thereby achieving an advanced DVD player.

Claims (2)

In the image data forming a frame with a combination of an I-picture, a P-picture, and a B-picture, each picture is composed of a plurality of pack data having a predetermined size, and each of the pictures in the pack data at the boundary between the pictures. And a double speed flag indicating whether or not the picture data is mixed. A high speed reproduction method characterized by performing double speed reproduction using the data structure of claim 1.

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