JP2004007819A - Method for recording signal on disk-shaped recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for recording signals on a disk-shaped recording medium by which a prescribed video-recording time is easily secured even when a video-recordable area becomes insufficient under a variable rate. <P>SOLUTION: An I picture is two-dimensional compressed video data which have been subjected to information compression inside a frame. A P picture is a three-dimensional compressed video data which have been subjected to information compression by adding movement compensation by the I picture in a temporally forward direction. A B picture is three-dimensional compression video data which have been subjected to information compression by adding movement compensation by the I or P picture in a temporally forward and backward directions. Digital data consisting of a video information block including a mixture of the I, P and B pictures are recorded in the recording area of the disk-shaped recording medium. Part of or the whole of the B picture of the video information block is reduced for recording. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to an optical disk and a method of recording a compressed moving image on the optical disk.

As the compression technology of digital video information advances, by recording the compressed information on a disk-shaped recording medium such as an optical disk, information searchability is improved compared to a tape-shaped recording medium such as a conventional VTR. It has become possible to realize an extremely convenient video filing device. In addition, since such a disk file device handles digital information, there is no deterioration of information due to dubbing as compared with the case where an analog signal is recorded, and since it is optical recording / reproduction, it is contactless and has high reliability. It is a very good thing because it can build a system.

In, a conventional optical disk device will be described below with reference to the drawings. FIG. 18 is a circuit block diagram of a conventional optical disk device that records a compressed moving image on an optical disk or the like or reproduces a compressed moving image from the optical disk.

In the figure, 1 is an A / D converter for converting an analog signal such as an input audio signal or video signal into a digital signal, 2 is an information compressor for compressing the signal digitally converted by the A / D converter 1, Reference numeral 3 denotes an encoder (encoding unit) that encodes the signal compressed by the information compression unit 2, and 4 denotes a modulation unit that converts the encoded signal into a predetermined modulation code in order to reduce intersymbol interference in a recording medium. 5 is a laser driving means for driving a laser according to the modulation code, 6 is an optical head for emitting a light beam corresponding to a modulation signal from the laser driving means and recording information on an optical disk 7, and 8 is a light from the optical head 6. A tracking actuator 9 for tracking the light beam; a traverse motor 10 for reciprocating the optical head 6 in the radial direction of the optical disk 7; Disk motor for rotating the optical disk 7 at a predetermined frequency, 11 is a motor driving means for controlling the tracking actuator 8, traverse motor 9 and the disk motor 10.

Reference numeral 12 denotes a reproduction amplifier for amplifying a reproduction signal from the optical head 6, 13 a demodulation unit for demodulating the reproduction signal modulated by the modulation unit 4, and 14 a decoding signal reproduced by the encoder 3. A decoder (decoding means) 15 is information decompression means for decompressing the reproduction signal information-compressed by the information compression means 2, and 16 is a digital signal converted to an analog signal to convert the original video signal, audio signal, etc. D / A conversion means for obtaining

FIG. 19 shows a simplified data array structure (layer structure) of the MPEG system, which is currently being standardized for compressing digital video information for transmission and storage. In the figure, reference numeral 17 denotes a GOP (Group of Picture) composed of predetermined pieces of frame information. In this example, one GOP is composed of 15 pieces of frame information.

# 18 is a GOP layer representing one piece of frame information and is composed of several picture layers. A picture layer 19 has a slice structure in which one picture is divided into several blocks. Here, Y represents luminance information, and Cb and Cr represent color information.

{Circle around (2)} 20 is a slice layer composed of several macroblocks (MB), 21 is a macroblock layer composing a macroblock, and 22 is a block layer composed of 8 × 8 pixels.

FIG. 20 shows an encoding structure when one GOP is configured from ten pieces of frame information. In the figure, reference numeral 23 denotes an I picture which is video information compressed by intra-frame DCT (discrete cosine transform); Reference numeral 24 denotes a P picture, which is video information in which information compression of the I picture 23 or more is performed in addition to DCT coding with motion compensation using the I picture 23 located in a temporally forward direction as a reference screen, and 25 denotes a temporal This is a B picture, which is video information that has undergone information compression of P pictures 24 or more in addition to DCT coding with motion compensation using the I picture 23 and P picture 24 located before and after as reference screens.

採用 By adopting such an encoding structure, it is possible to increase the encoding efficiency and increase the data recording capacity on the optical disc 7.

However, since the I-picture 23 performs intra-frame DCT, it is possible to reproduce image information by itself, but the P-picture 24 performs forward motion compensation in addition to the intra-frame DCT. Therefore, the image cannot be reproduced unless the I picture 23 has been reproduced. Further, the B picture 25 is a prediction screen using motion compensation in both the forward and backward directions, so that the I picture 23 and the P picture 24 There is a drawback that reproduction is impossible only after reproducing both pictures. For this reason, if the number of B pictures 25 is increased, the amount of buffer memory in the processing circuit is increased, and the delay time from data input to video reproduction is increased. While an encoding method with good compression efficiency is desired for recording, the delay time of video reproduction processing does not cause much problem, and thus such an encoding structure is suitable.

FIG. 21 shows that when the compressed information is recorded on the optical disc 7 with the data length being variable according to the picture so that the image quality of all the images is constant, the data amount per GOP occupies the recording area of the optical disc 7. It is the schematic diagram which showed the ratio. In the figure, 26 indicates the data amount per GOP.

FIG. 22 shows a comparison between the case where the compressed image is recorded at the same variable rate as in FIG. 21 (a) and the case where the compressed image is recorded at the fixed rate in the recording area of the optical disk 7 (b). In the figure, reference numeral 27 denotes the entire recording area of the optical disk 7, reference numeral 28 denotes the innermost circumference of the disk which is the start point of the above-mentioned entire recording area 27, and reference numeral 29 denotes the outermost circumference of the disk which is the end point of the above-mentioned recording area 27.

FIG. 23 is a plot of the amount of data per GOP required to keep the quality of the reproduced image constant regardless of the image, with the horizontal axis representing time. In the figure, a indicates the maximum value of the data amount per GOP, and b indicates the average data amount of each GOP.

In FIG. 24, the image S / N indicating the image quality is plotted on the horizontal axis, and the data amount per GOP required to realize a predetermined image S / N for each type of image is plotted on the vertical axis. .

Next, the operation of the conventional optical disk device will be described.
Conventionally, in order to record compressed moving image information on an optical disk, a method of recording digital compressed moving image information such as the MPEG system shown in FIG. 19 on an optical disk recorder as shown in the block diagram of FIG. 18 has been adopted. . At this time, the video information digitized by the A / D conversion means 1 is converted by the information compression means 2 into a standard compressed moving image system such as MPEG. The compressed information is encoded by the encoder 3, and is subjected to a predetermined modulation by the modulating means 4 in order to reduce the influence of intersymbol interference on the optical disk 7, and thereafter, the optical head 6 driven by the laser driving means 5. It is recorded on the optical disc 7.

At this time, if the recording is performed at a fixed rate where the data amount in each GOP unit is substantially the same, information is distributed to sectors equal to an integral multiple of the frame period, thereby making the recording time per optical disk 7 constant. Can be kept.

On the other hand, at the time of reproduction, the video information recorded on the optical disk 7 is amplified by the reproduction amplifier 12, restored to the original video information by the demodulation means 13 and the decoder 14, further expanded by the information expansion means 15, and The original analog video information signal can be displayed on a monitor (not shown) or the like by the A conversion means 16.

When the MPEG method is used as a digital moving image compression method in such an optical disk device, as shown in FIG. 20, an I picture 23 which is compressed video information by intra-frame DCT and an I picture 23 which is temporally located in the forward direction. Is a compressed picture information obtained by adding motion compensation using DCT coding to the reference picture as a reference picture, and motion compensation using the I picture 23 and P picture 24 located before and after in the reference picture is used as the DCT coding. An encoding structure in which the added compressed picture information and the B picture 25 are combined as shown in FIG.

However, when the recording method using the fixed rate is adopted, the recording time per optical disc 7 can be kept constant as described above, but as shown in FIG. Compared to a recording method using a variable rate in which the data amount is variable (FIG. 22A), generally, a larger data recording area is required to record image information of the same number of frames. In other words, there is a problem that a predetermined recording time (for example, 2 hours) cannot be secured depending on the type of data to be recorded and the selection of the recording rate.

This is clearer from FIGS. 23 and 24. That is, since a general video file differs in the fineness and the amount of motion of each image depending on the picture, as shown in FIG. 24, if the same image S / N is obtained for all the images, one GOP per GOP is obtained. The data amount differs greatly for each image.

Therefore, in order to keep the image quality of all pictures below a certain level, the recording rate should be fixed to the maximum value of the amount of data per GOP as shown in FIG. Is required. As a result, there is a useless GOP having a large data amount, and a large data recording area is required.

On the other hand, in the recording at the variable rate, the recording rate according to the type of each image is selected, so that the recording rate b in FIG. 23 can be recorded as the average recording rate. Therefore, the problem of the fixed rate described above does not occur, and as a result, the recording time can be extended by the difference from the maximum recording rate a.

By taking advantage of such a variable rate, in a read-only type optical disc apparatus capable of pre-evaluating an entire video file, the average recording rate of the entire video file is adjusted by repeating encoding. In, the recording time of one optical disk 7 is increased while maintaining the image quality constant, and a predetermined recording time is obtained.

However, when the recording at the variable rate as described above is applied to a recordable optical disk, unlike the case of manufacturing a read-only optical disk, the following problems occur.
In other words, in the case of producing a read-only optical disk, when recording an image, information such as the fineness of the picture and the speed of movement of the video file to be recorded is already known. Therefore, it is possible to predict in advance the average recording rate for recording information for a predetermined time on a single optical disc with a constant image quality. However, in a recordable optical disc for recording, for example, a TV movie, etc. Usually, it is not possible to know in advance information such as the fineness of the picture and the speed of movement of the picture file to be recorded, and it is not possible to predict the average recording rate in advance.
Therefore, the recording time of an optical disk having a limited disk capacity becomes variable due to the fineness of the pattern of the video to be recorded and the speed of movement, and the recording time of the optical disk cannot be determined in advance. This causes a problem.

The present invention has been made in order to solve the above-described problem, and in a recording apparatus that employs a variable rate in which a recording rate changes in accordance with the movement of an image, the fineness of a picture of a video file to be recorded and the like. Even in the case of recording image information on a disc for which information such as the speed of movement cannot be known in advance, it is possible to increase the recordable time while minimizing the deterioration of image quality, thereby making it possible to record one image. It is an object of the present invention to obtain an optical disc and a recording method that can ensure a predetermined recording time on an optical disc.

The recording method for a disk-shaped recording medium according to the present invention is characterized in that an I picture which is two-dimensional compressed video data information-compressed in a frame and a three-dimensional The video information block includes a P picture which is compressed video data and a B picture which is a three-dimensional compressed video data which is information-compressed by adding motion compensation by an I picture or a P picture in a temporally forward and backward direction. A recording method for recording digital video data in a recording area of a disk-shaped recording medium, wherein a part or all of the B picture of the video information block is reduced and recorded.

In another optical disc according to the present invention, digital video data recorded in a recording area of a disc-shaped recording medium is different from an I picture, which is two-dimensional compressed video data in which information is compressed in a frame, in a temporally forward direction. A P-picture, which is three-dimensional compressed video data that is information-compressed by adding motion compensation by an I-picture, and a three-dimensional compressed video data that is information-compressed by adding motion compensation by an I-picture or a P-picture in a temporally forward and backward direction. Digital video data composed of video information blocks each having several frames to several tens of frames as a unit, in which a certain B picture is mixed. The header of the video information block contains the address of the video information block, Is characterized by recording a time code describing an elapsed time from the start time.

In another optical disc according to the present invention, digital video data recorded in a recording area of a disc-shaped recording medium is different from an I picture, which is two-dimensional compressed video data in which information is compressed in a frame, in a temporally forward direction. A P-picture, which is three-dimensional compressed video data that is information-compressed by adding motion compensation by an I-picture, and a three-dimensional compressed video data that is information-compressed by adding motion compensation by an I-picture or a P-picture in a temporally forward and backward direction. Digital video data composed of video information blocks each having several frames to several tens of frames as a unit in which a certain B picture is mixed, and I, P, B pictures in the video information block are added to the header of the video information block. And an overwriting flag indicating whether or not overwriting is possible is recorded.

According to another recording method of the present invention, digital video data recorded in a recording area of a disc-shaped recording medium is temporally different from an I picture which is two-dimensional compressed video data information-compressed in a frame. P-picture, which is three-dimensional compressed video data that is information-compressed by adding motion compensation by a forward I-picture, and 3-dimensional compression that is information-compressed by adding motion compensation by temporally forward-backward I-pictures or P-pictures When recording data on an optical disc, which is digital video data composed of video information blocks having a unit of several frames to several tens of frames in which a B picture, which is video data, is mixed, the last recorded video on the optical disc to be recorded is Calculates the recordable free space on the optical disk based on the address of the last video information block, and displays the remaining time on the screen. It was carried out, in which to select whether to overwrite recording according to the selection of the user.

Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a configuration of a recording system of an optical disc device according to Embodiment 1 of the present invention.

In the figure, 101 is A / D conversion means for converting an input analog video signal into a digital signal, 102 is motion detection means for detecting a motion vector of a digitized video signal, and 103 is data compression. Discrete cosine transform means (DCT coding means), which is one of band compression techniques for converting a digital video signal into a spatial frequency in a vertical / horizontal direction; 104, an adaptive quantization means for quantizing the converted digital video signal; 105 is an inverse quantization means, 106 is an inverse discrete cosine transform means (IDCT decoding means) for restoring the original digital video signal from the spatial frequency component, and 107 is a reference image based on the motion vector from the motion detection means 102. Is a variable length encoding means for encoding a quantized digital video signal. Reference numeral 109 denotes a buffer memory, and 110 denotes a hierarchy of upper and lower two-layer data by rearranging the data arrangement of the encoded digital video signal on the buffer memory 109, and address information and attribute data are added to the hierarchized signal. A format encoder 111 for formatting by adding header information such as header information, a modulation unit 111 for applying a modulation to the formatted and hierarchized digital video signal to prevent intersymbol interference on the optical disk, and a modulation unit 111 Laser modulation means for modulating a recording laser based on information from the optical disc; 113, an optical disc on which information is recorded by a method such as magneto-optical recording or phase change recording; 114, an optical disc based on the recording laser modulated by the laser modulation means 112 Optical head for recording information on 113, 11 Is a feed motor for moving the optical head 114 in the radial direction of the optical disk 113; 116 is a disk motor for rotating the optical disk 113 at a predetermined frequency; 117 is focus / tracking control of the optical head 114; control of the feed motor 115; Circuit controller 118 generates a control signal for the servo circuit 117, the format encoder 110, and the like, and a system controller for controlling the entire apparatus by controlling the apparatus. 119 reproduces header information of video data recorded on the optical disk 113. The reproducing amplifier 120 is a header recognizing means for recognizing an overwritable area from the reproduced header information.

FIG. 2 is a schematic configuration diagram showing a configuration of a reproduction system for reproducing information from the optical disk 113 on which the digital video signal is recorded as described above.
In the figure, 121 is a reproduction amplifier for reading information recorded on the optical disk 113, 122 is a data detection and PLL circuit for extracting data from the signal read by the reproduction amplifier 121, and 123 is for detecting an error in the extracted data. An error correction means for correcting, 124 is a header detection / data division means for reproducing header information from the error-corrected data to separate and output data for each layered data, and 125 and 126 are for each divided data. This is a decoder for decoding hierarchical data.

FIG. 3 is a block diagram showing a specific configuration of the decoder 125. Although not shown, the decoder 126 has a similar configuration.
In the figure, 127 is a variable length decoding means for decoding by using the upper layer data divided by the header detection / data division means 124 as input, 128 is an inverse quantization means, 129 is an inverse discrete cosine transform means, and 130 is a variable length This is a motion compensation unit that performs motion compensation on digital data decoded by the decoding unit based on the reference image stored in the frame memory 107.

FIG. 4 shows a data arrangement structure of a digital video signal, which is basically the same as that described in FIG. 19 of the conventional example.
Here, in the figures, (a) to (g) show new file blocks obtained by dividing a macroblock layer of a digital video signal subjected to DCT encoding into vertical / horizontal spatial frequencies. I have. Here, the closer to (a), the closer to the DC component, while the closer to (g), the closer to the high frequency region.
In addition, 131 is a slice, 132 is a slice layer, and 133 is a macroblock layer.

FIGS. 5A to 5C are conceptual diagrams for explaining the concept of data overwriting, which is a feature of the present invention, in chronological order. Here, a case where, for example, 120 minutes of video data is recorded at a variable rate on the optical disc 113 is described as an example.
In the figure, S indicates the start time of video data recording, E indicates the end time of video data recording, I indicates the innermost circumference of the recording area of the optical disc 113, and O indicates the outermost circumference of the recording area of the optical disc 113.

FIGS. 6A and 6B are diagrams showing a specific procedure of the data overwriting method of the present invention described with reference to FIG. 5 on the recording area of the optical disk 113, wherein FIG. (B) is a state in which the fact that the recording time has run short due to the adoption of the variable rate is recognized based on the information from the header recognition means 120, and the recorded area is overwritten (shaded area). Is shown.
Here, the GOP structure of the present invention has the same configuration as that shown in FIG. 20 of the conventional example, and the lower part in the figure indicates the lower layer of the hierarchical data divided into two parts. For example, it represents video data having a small number of pixels and lines (for example, 360 pixels × 240 lines) or low-frequency data in DCT encoded data, and the upper part indicates the upper layer of the divided hierarchical data. This represents video information having a large number of pixels and lines (for example, 720 pixels × 480 lines) or high frequency data in DCT encoded data.

GOPm represents the m-th GOP, and each GOP has a GOP header 134, I-picture lower data 135, I-picture upper data 136, P-picture lower data 137, P-picture upper data 138, B-picture lower data 139, The B picture upper data 140 is recorded in the order.
Here, when performing overwriting, according to the present invention, the overwriting is performed not only on the lower data, which is essential information on video data reproduction, but only on the upper data, which is detailed data on video reproduction, The recording is performed by overwriting only the lower data of the picture. Here, reference numerals 141 to 146 denote a GOP header, I picture lower data, P picture lower data, and B picture lower data of the nth GOP to be overwritten.
The data to be overwritten is divided and overwritten on the data to be overwritten as necessary for the information amount of each data.

Next, the operation of the present embodiment will be described.
At present, in the MPEG system, which is being adopted as an international standard, recording is performed by a combination of the encoding system and the optical disk drive device described with reference to FIG.

The video signal digitized by the A / D converter 101 is detected by the motion detector 102 in the form of a motion vector in the form of a motion vector for each screen (frame). , And is adaptively quantized by the adaptive quantization means 104.

In the present invention, video information is recorded in a GOP that forms one video information unit in several to several tens of frames. However, as described in the conventional example, the compression operation is performed by one video itself. A two-dimensional compressed video (I picture) and a three-dimensional compressed video (P picture, B picture) to be compressed by adding a prediction screen using a motion vector from a temporally forward or backward video. It is composed in a mixed form. The purpose is to mix the two-dimensional compressed image that is effective at the time of retrieval because it can be reproduced with one image, and the three-dimensional compressed image with excellent compression efficiency instead of being able to reproduce with one image. The object is to achieve both searchability and compression efficiency.
Therefore, as shown in FIG. 1, the prediction screen necessary for obtaining the three-dimensional compressed image is restored by decoding the video data from the adaptive quantization means 104 by the inverse quantization means 105 and the inverse discrete cosine transform means 106. , On the frame memory 107 using the motion vector from the motion detecting means 102.

Next, the adaptively quantized compressed digital video data is subjected to variable-length encoding according to the amount of motion vector by the variable-length encoding means 108, and is temporarily stored in the buffer memory 109.
The compressed digital video data stored in the buffer memory 109 is rearranged by the format encoder 110 instructed by the system controller 118 to rearrange the data arrangement and the like in each GOP, hierarchized, and information such as a header is added. After that, it is output from the format encoder 110.

The digital video information thus formatted / hierarchized is modulated by the modulation means 111 so as to eliminate intersymbol interference on the optical disk 113, and is recorded on the optical disk 113 by the optical head 114 via the laser modulation means 112. Is done.

As the recording progresses sequentially, the system controller 118 detects that the recordable area of the optical disk 113 decreases (FIGS. 5A and 5B) and that the recordable area is exhausted through the output of the reproduction amplifier 119 and the header recognition means 120. Then (FIG. 5 (b)), the header of the previously recorded video data is read out by the header recognizing means, and based on the header, the lower layer of the video data input to the next stage is compared with the upper layer data of the recorded video data. The data overwriting is sequentially performed from the innermost circumference of the recording area of the optical disk (FIG. 6). By doing so, the recordable time can be lengthened, and even if the predetermined recording time is insufficient under the variable rate, the insufficient time can be supplemented by overwriting to reliably obtain the predetermined recording time ( FIG. 5 (c)). In this case, it is necessary that the read data rate and the recording data rate be faster than the data rate of a normal video signal.

Next, a description will be given of the hierarchical structure of the video data and the operation of the reproduction system for implementing the overwriting operation.
At present, the MPEG standard, which is being adopted as an international standard, employs a hierarchical structure called a scalable structure. This is a method of dividing the video data into video data of a lower layer of 360 pixels × 240 lines and video data of an upper layer from which video data of 780 pixels × 480 lines can be obtained by combining the data. In the video data divided in this way, the video data of the upper layer and the video data of the lower layer are combined by the decoding method shown in FIGS. 2 and 3, and 780 pixels × 480 lines as digital video information of the upper layer are combined. Can be obtained.

That is, the video signal read out by the reproduction amplifier 121 is reproduced by the data detection / PLL means 122, and after error detection / correction is performed by the error correction means 123, 780 pixels × 480 lines are output by the header detection / data division means 124. Are divided into lower layer video data of 360 pixels × 240 lines. The divided lower layer video data is decoded by the decoder 126 to obtain a lower layer decoded picture. The upper layer video data is decoded by the decoder 125 and then added to the lower layer video data. By doing so, it is possible to obtain an upper layer decoding screen.

As another data hierarchization method, for example, as shown in FIG. 4, a method of dividing data into low and high frequency DCT coefficients and hierarchizing the data can be considered. This division method is a method called data partitioning in the MPEG standard.
In the standard digital moving picture video compression system represented by MPEG, JPEG, etc., as shown in FIG. 4, an I picture is composed of a picture layer 131 obtained by dividing one screen into several slices, and the number of one slice among these. It is composed of a slice layer 132 divided into such macroblocks (MB), and a macroblock layer 133 divided from one macroblock in the slice layer. Here, the macroblock layer 133 is composed of image data corresponding to DCT coefficients of 8 × 8 pixels. The spatial frequency when the macroblock is subjected to DCT coding is divided in the vertical / horizontal direction, and data obtained by zigzag scanning is obtained. It has an array structure.
Here, 63 DCT encoded data in the figure are decomposed into seven blocks (a) to (g) in units of nine.

In the recording using data partitioning, data is not recorded, for example, by sequentially recording I-picture data in units of slices, but is recorded in units of (a) to (g), and in units of frequency ranges. Header information, a parity signal, and the like are added to the head of the divided block. By recording in this way, even for data having a relatively large amount of information, such as an I picture, the low frequency component of DCT encoded data, that is, a relatively close DC component, without reproducing all of the I picture data. An image can be obtained by reproducing only data. In the present invention, video data is hierarchized into two layers, upper and lower layers, by this data partitioning, and data is overwritten on the upper layer, that is, data that is relatively close to high frequency components, thereby increasing the recordable time, The required recording time can be reliably obtained even under a variable rate.

In the video data hierarchized by the above-described method, for example, only the data of the lower layer composed of the data of the low frequency component of the DCT coefficient and the number of lines of a small number of pixels is acceptable if a certain degree of image quality deterioration is allowed. Reproduction is possible. By utilizing this point, the present invention can secure a predetermined recording time by overwriting the upper layer data of the video data of the previously recorded area when the recording time is insufficient due to the recording at the variable rate. It was made.
Embodiment 2 FIG.

Next, a second embodiment of the present invention will be described with reference to the drawings.
In the first embodiment described above, data in the upper layer of all screens (frames) is overwritten, but this has the following disadvantages.
That is, the video data can be roughly classified into video data of fast movement and video data of slow movement based on the movement of the image, but the video data of fast movement is lost by overwriting. Since the upper layer data greatly affects the image quality of the reproduced image, if this is deleted, the viewer can easily recognize the deterioration of the image quality.

In view of this, the present embodiment aims to eliminate the drawbacks of the first embodiment by discriminating whether or not to perform overwriting with fast-moving video data and slow-moving video data. And

FIG. 7 is a schematic configuration diagram showing a configuration of a recording system of the optical disc recording / reproducing apparatus according to the present embodiment.
In the figure, the same or corresponding components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Reference numeral 142 denotes a motion vector amount determining unit that outputs a signal when detecting that the motion vector amount from the motion detecting unit 102 is equal to or smaller than a predetermined value, which is a characteristic configuration of the present embodiment.

FIG. 8 shows a data recording structure of video data recorded by the recording apparatus of FIG. 7, particularly a header portion provided at the beginning of a GOP and at the beginning of each hierarchical data.

In the figure, 143 is a GOP header including an I picture lower header, 144 is I picture lower layer data, 145 is I picture upper layer data, 146 is P picture lower layer data, 147 is P picture upper layer data, 148 is I picture An upper header, 149 is a P picture lower header, and 150 is a P picture upper header.
Reference numerals 151 to 160 denote the configuration of the GOP header 143 excluding the I-picture lower header, 151 denotes a video GOP address for storing the current address, 152 denotes an I-picture data amount and the like. Video attribute data 153, which is data for determining the required buffer memory amount, indicates whether or not a hierarchical structure corresponding to the number of pixels or lines of a screen is provided by providing an area in which attributes in a digital moving image are described. The scalability mode, 154 is the number of frames for recording the number of frames constituting the GOP, 155 is the GOP structure indicating the arrangement structure of I pictures, P pictures, and B pictures in the GOP, and 156 is a predetermined A flag is recorded when it is determined that the value is less than the motion vector amount. The possible flag 157 is detailed attribute data that records whether the video in the GOP is pan, zoom, or data including a scene change. 158 describes the elapsed time from the start of recording or the start of the movie. This is a time code, which is data obtained, and is used, for example, for display on a screen by a character generator or the like. 159 is a jump destination address where the next overwritable address is recorded, and 160 is a spare area for recording other information.

FIG. 9 shows an operation sequence from recording standby to recording start in the optical disk recording apparatus according to the present embodiment. FIG. 10 shows an operation sequence of the recording apparatus when the user selects the overwrite mode in the process of the operation sequence shown in FIG. 9, and FIG. 11 shows a case where the user does not overwrite, contrary to FIG. 9 shows an operation sequence of the recording device when the normal recording mode is selected.

FIG. 12 is a conceptual diagram showing the concept of overwrite recording by the recording apparatus of the present embodiment. In the figure, S indicates the start time of video data recording, E indicates the end time of video data recording, I indicates the innermost circumference of the recording area of the optical disc 113, and O indicates the outermost circumference of the recording area of the optical disc 113.

FIGS. 13A and 13B are diagrams showing a specific procedure of the data overwriting method described in FIG. 12 on the recording area of the optical disk 113, and FIG. 13A shows a case where overwriting is not performed. (B) shows that the recording time is short due to the adoption of the variable rate. Based on the information from the header recognizing means 120 and the presence or absence of the flag recorded in the header of each GOP, the data is already recorded. This shows a state in which the area has been overwritten (shaded area). FIG. 4 shows a state in which, when the overwrite possible flag is set to GOPm, GOPm + 3, GOPm + 4, GOPm + 7, the upper layer data of the GOP is overwritten with the lower layer data of GOPn and GOPn + 1.

Next, the operation of the present embodiment will be described.
Also in the present embodiment, the digital video data has a GOP structure composed of a plurality of screens, and as shown in FIG. 20 of the conventional example, a two-dimensional compressed screen of an I picture, a B picture, and a P picture. , And three-dimensional compressed screens.

First, the video signal digitized by the A / D conversion means 101 is detected by the motion detection means 102 for each screen (frame) in the form of a motion vector in the form of a motion vector. It is converted to a spatial frequency in the horizontal direction, and is adaptively quantized by the adaptive quantization means 104. At this time, in the present embodiment, the motion vector detected by the motion detecting means 102 is also sent to the motion vector amount determining means 142, where the motion vector amount of each video screen is compared with a predetermined value. When it is detected that the motion vector amount is equal to or smaller than a predetermined value (that is, when the video has a slow motion), an output signal is sent to the system controller 118.

On the other hand, the compressed digital video data quantized by the adaptive quantization means 104 is subjected to variable-length coding according to the amount of motion vector by the variable-length coding means 108, and is temporarily stored in the buffer memory 109.
The compressed digital video data stored in the buffer memory 109 is rearranged by the format encoder 110 instructed by the system controller 118 to rearrange the data arrangement and the like in each GOP, hierarchized, and information such as a header is added. However, if there is an output of the motion vector amount determining means 142, an overwrite possible flag is added to the header information.

The digital video information thus formatted / hierarchized is modulated by the modulation means 111 so as to eliminate intersymbol interference on the optical disk 113, and is recorded on the optical disk 113 by the optical head 114 via the laser modulation means 112. Is done.

When the system controller 118 detects that the recordable area of the optical disk 113 decreases and the recordable area disappears as the recording proceeds, the system controller 118 detects through the output of the reproduction amplifier 119 and the header recognizing means 120 that the header of the previously recorded video data is header. It is read from the recognition means, and overwrites a part of the recorded video data based on the header, that is, the upper data with the overwritable flag set, overwriting the data in the lower layer of the video data input to the next stage on the optical disc. It is performed sequentially from the innermost circumference of the recording area. By doing so, even if the predetermined recording time is insufficient under a variable rate, the insufficient time can be supplemented by overwriting and the predetermined recording time can be reliably obtained. It is possible to overwrite only a video screen with a small motion vector amount with little image quality degradation due to overwriting without overwriting a video screen with a large vector amount, so that it is possible to obtain video information with excellent image quality as a whole. In this case, it is necessary to set the read data rate and the recording data rate faster than the data rate of the normal video signal, as in the first embodiment.

Further, in this embodiment, since it is necessary to perform overwriting depending on the presence or absence of the overwritable flag, as shown in FIG. 8, due to the data structure, the header 148 for indicating the top data position of the upper and lower layers of each picture, Since 149 and 150 are provided, it is possible to take out I picture data alone or take out P picture alone. As a result, there is also an effect that dubbing and editing can be easily performed in GOP units. In this case, it is preferable to arrange the audio data in GOP units in accordance with the video information.

Further, in the present embodiment, the scalability mode 153, the number of frames 154, and the GOP structure 155 in which the attributes of the data are described in the digital video data are provided in the GOP header 143, so that it is possible to support a plurality of signal processing systems. It becomes possible. Further, since the current address, the next overwrite address, and the time information are recorded in the video GOP address 151 and the time code 158, continuous reproduction of the overwrite data and special reproduction / search can be easily performed.

In the above description, the overwriting is performed only on the upper layer data of the GOP for which the overwriting enabled flag has been set, but the motion vector amount exceeds the predetermined value by the motion vector amount determining means 142. By setting an overwrite enable flag for data that moves fast, the same effect can be obtained even if the GOP with the overwrite enable flag set is prohibited from being overwritten.

Next, the specific operation of the above-described optical disk recording apparatus will be described with reference to the flowcharts of FIGS.

First, when the apparatus is turned on or in a recording standby state, for example, as shown in FIG. The number of sectors in the recordable open area is calculated. In this case, even if it is calculated by storing the recording end GOP address at the end of the previous recording in the TOC (Table of content) area in advance, or the optical head 114 is actually searched for the open area, The recording start GOP address may be read.

Next, when recording is performed as it is, the extent to which the recording area of the optical disk 113 is full is displayed on the screen as a remaining time by a character generator or the like, and the recording is performed even if the user overwrites the image and a little image quality deterioration is prepared. The user is allowed to select whether to give priority to time or to give priority to image quality and not to overwrite, and then start recording.
Hereinafter, the case where the overwrite is selected and the case where the overwrite is not selected will be described.

FIG. 10 is a flowchart when the overwrite mode is selected.
As shown in the figure, first, when recording is started, it is determined whether or not the overwrite mode is necessary from the relationship between the blank area of the data on the optical disk 113 and the predetermined recording time. Here, when the overwrite mode is selected by the user and it is detected that the blank area has disappeared, the video encoder constituted by the discrete cosine transform means 103, the adaptive quantization means 104, and the variable length coding means 108 Only the lower layer data of the video data is written to the buffer memory 109, formatted, and added with header information and the like. Further, the next overwriteable GOP address is written in the header of the buffer memory 109.

Next, the header portion of the GOP of the already recorded area to be overwritten is reproduced by the reproducing amplifier 119 and the header recognizing means 120, and it is confirmed whether or not the overwriting possible flag is set in the header portion. For example, the lower layer data written in the buffer memory 109 is written in the upper layer data area of the GOP. Conversely, if overwriting is impossible, the next GOP address is accessed, and the presence or absence of an overwriting enable flag is checked in the same manner as described above. If overwriting is possible, data is overwritten. By repeating this operation, it is possible to easily secure a predetermined recording time even under a variable rate, and it is possible to minimize image quality deterioration.
When performing the overwriting operation, it is necessary to set the data rate for recording and reproducing data from the optical disk 113 higher (for example, about twice) than the data rate required for reproducing the video information. is there. This is because the portion to be overwritten is not continuously arranged on the optical disk 113 but is distant, so that it is necessary to consider a search time and a rotation waiting time for a track jump or the like.

Also, in this embodiment, the presence or absence of the overwrite flag is directly confirmed by sequentially reproducing the header of the previously recorded GOP as described above. At the end of the second recording, it is also possible to write all the addresses of the flagged GOP in the TOC area, and reproduce and store this address before performing the overwrite recording.

Further, in the present embodiment, the data to be overwritten is only the lower layer data as in the first embodiment, but the magnitude of the motion vector amount is also determined for the data to be overwritten, and It is effective to overwrite not only the lower layer data but also the upper layer data of the video information in order to equalize the image quality of the reproduced image.

FIG. 11 is a flowchart in the case of normal recording in which overwriting is not selected.
In this case, the format encoder 110 performs hierarchization and formatting of the upper and lower layers, and determines whether or not the GOP is overwritable by the motion vector amount determination means 142, and the motion vector amount is smaller than a predetermined value and can be overwritten. When it is determined that the GOP header 143 and the picture headers 148, 149, and 150 are set, the overwrite enable flag is set by the buffer memory 109 for performing format conversion and the format encoder 110. By repeating the above operation until the end of recording, a normal recording operation is performed. Here, if the remaining recording area is insufficient for the predetermined scheduled recording time during the recording, the mode is changed to the overwrite mode from the middle only when the overwrite permission is obtained from the user. Recording is performed, but otherwise, the recording ends at that point.

As a result, the overwritten data becomes as shown in FIG. 13B, and the data is overwritten only on the upper layer data portion of the GOP for which the overwrite enabled flag is set.
Embodiment 3 FIG.

Next, a third embodiment of the present invention will be described.
In the first and second embodiments, video data is first divided into an upper layer and a lower layer for each of an I picture, a P picture, and a B picture, and the pictures are recorded on an optical disc in the order of lower and higher for each picture. However, in this method, the continuity of the data is interrupted by overwriting, and the reproduction must be performed in consideration of the track jump of the optical head and the rotation waiting time of the optical disk at the time of reproduction. Will be burdened.
The present embodiment solves the problem of such an apparatus, and will be described below with reference to the drawings.

14A and 14B are diagrams showing a data arrangement on a recording area of an optical disk recorded according to the present embodiment, wherein FIG. 14A shows a data arrangement state before overwriting, and FIG. 14B shows a data arrangement state after data overwriting. Is shown.

In the figure, 161 is the header information of the m-th GOP, and includes the picture header of the I picture lower layer data 162. 162 is the I picture lower layer data of the mth GOP, 163 is the P picture lower layer data, 164 is the B picture lower layer data, 165 is the upper layer data of I, P, B pictures, 166 is the P picture lower layer header, 167 is a B picture lower layer header, 168 is an I, P, B picture upper layer header, 169 is header information of the (m + 1) th GOP, and includes a picture header of I picture lower layer data 170. Reference numeral 170 denotes I-picture lower layer data of the (m + 1) th GOP, 171 denotes P picture lower layer data, 172 denotes B picture lower layer data, 173 denotes P picture lower layer header, and 174 denotes B picture lower layer header. Reference numeral 175 denotes header information of the n-th GOP overwritten in the present embodiment, and includes a picture header of I-picture lower layer data 176. 176 is the I picture lower layer data of the nth GOP to be overwritten, 177 is the P picture lower layer data of the nth GOP to be overwritten, 178 is the P picture lower layer header, 179 is the mth GOP information is the mth Is a sub-header of an overwrite GOP having header information for remaining data that cannot be completely recorded in the upper layer data area of the GOP information and is overwritten on the upper layer data area of the (m + 1) th GOP information. The picture header of the P picture lower layer data 180 is included. Reference numeral 180 denotes P picture lower layer data of the nth GOP to be overwritten, 181 denotes B picture lower layer data of the nth GOP to be overwritten, and 182 denotes a B picture lower layer header.

In the present embodiment, as shown in the figure, each picture divided into upper layer data and lower layer data is arranged after the upper layer data to be overwritten and the lower layer data not to be overwritten are fixed in one GOP. It is characterized in that it is configured to perform With this configuration, even if overwriting is performed, the continuity of data in each GOP can be maintained, the operation of searching the overwriting area at the time of recording is simplified, and the optical The number of track jumps of the head can be reduced, and the necessity of performing reproduction in consideration of the rotation waiting time of the optical disk also decreases.
Embodiment 4 FIG.

Next, a fourth embodiment of the present invention will be described.
In the above-described third embodiment, the upper layer data and the lower layer data of each picture in one GOP are arranged after being fixed, but in the present embodiment, a plurality of GOPs Is characterized in that upper layer data and lower layer data of each picture are fixedly arranged in units of.
FIGS. 15A and 15B are diagrams showing a data array on a recording area of an optical disk recorded according to the present embodiment, wherein FIG. 15A shows a data array state before overwriting, and FIG. 15B shows a data array state after data overwriting. Is shown. Also, for the sake of explanation, the present embodiment will be described using two GOPs as a unit.

In the figure, reference numeral 183 denotes header information of the m-th GOP, which includes a picture header of the first I picture lower layer data 184. 184 is the first I picture lower layer data of the mth GOP, 185 is the second I picture lower layer data, 186 is the first P picture lower layer data, 187 is the second P picture lower layer data, 188 Is lower layer data of the first B picture, 189 is lower layer data of the second B picture, 190 is upper layer data of the first I, P, B picture, and 191 is upper layer data of the second I, P, B picture. Layer data, 192 is a second I picture lower layer header, 193 is a first P picture lower layer header, 194 is a second P picture lower layer header, 195 is a first B picture lower layer header, 196 is a first 2 B picture lower layer header, 197 is a first I, P, B picture upper layer header, and 198 is a second I, P, B picture upper layer header. Reference numeral 199 denotes the header information of the n-th GOP overwritten in the present embodiment, including the picture header of the first I-picture lower layer data 200. 200 is the first I picture lower layer data of the overwritten nth GOP, 201 is the second I picture lower layer data of the overwritten nth GOP, and 202 is the first I picture lower layer data of the overwritten nth GOP. P-picture lower layer data 203, the second P picture lower layer data of the n-th GOP overwritten, 204 a part of the first B picture lower layer data of the n-th GOP overwritten, 205 A second I picture lower layer header, 206 is a first P picture lower layer header, 207 is a second P picture lower layer header, and 208 is a first B picture lower layer header.

In the present embodiment, as shown in the figure, each picture divided into upper layer data and lower layer data is arranged after solidifying upper layer data to be overwritten and lower layer data not to be overwritten in two GOPs. It is configured to With this configuration, even if overwriting is performed, the continuity of data in each GOP can be maintained, and the number of track jumps of the optical head during reproduction can be reduced. The necessity of performing the reproduction in consideration of the waiting time is reduced. Furthermore, since two GOPs are set as a new unit GOP, data continuity in a larger data area can be provided, so that the rotation waiting time of the optical disc during overwriting or reproduction of overwritten data can be reduced. The number of track jumps and the number of data searches of the optical head can be reduced to half of that in the third embodiment using one GOP as a unit. However, in the present embodiment, format conversion and inverse conversion are performed using a plurality of GOPs as one unit, so that a large-capacity buffer memory for storing data is required. Therefore, it is appropriate to set about several GOPs as one unit.
Embodiment 5 FIG.

Next, a fifth embodiment of the present invention will be described.
The present embodiment is characterized in that a B picture in a slow-moving GOP is overwritten and partially rewritten. This is based on the fact that in a slow-moving GOP, even if the B-picture is partially deleted, the viewer does not notice much deterioration in the image quality of the reproduced image. Here, the reason why the screen to be deleted is a B picture is that when an I picture or a P picture is deleted, some B pictures become unplayable. This is because such a case does not occur when the B picture is deleted.

FIG. 16 shows an arrangement of each picture data according to this embodiment.
In the figure, I indicates an I picture, B indicates a B picture, P indicates a P picture, and the suffix number indicates the number of pictures in one GOP. Also, in the present embodiment, the data arrangement of each picture in one GOP is, as shown in FIG. 20 of the conventional example, like I, B1, B2, P1, B3, B4, P2, B5, B6, P3. Are located in (FIG. 16 (a))
Here, 209 is a B picture overwrite header, 210 is a P picture header, and 211 is a B picture header.

In the present embodiment, such a data array is rearranged as I, P1, P2, P3, B1, B3, B5, B2, B4, B6 on the recording area of the optical disk 113 by the format encoder 110 and the buffer memory 109. (FIG. 16B), and a B picture overwrite header 209 is further provided. Then, based on the overwrite header 209, B2, B4 and B6 in the GOP data are overwritten. In this case, since one of the three playback screens is deleted, the image quality is degraded. However, since this screen is a GOP with little movement, the viewer is not worried. In this manner, in the present embodiment, a predetermined recording time can be easily secured even if the recordable area is insufficient under the variable rate. If the GOP is data with almost no motion such as a still image, even if all the B pictures of the GOP are deleted, the viewer may feel a slight deterioration in reproduction image quality. There is no problem because is a still image.
Embodiment 6 FIG.

FIG. 17 shows a data arrangement of the configuration of the fifth embodiment on a recording area of an optical disc in which a plurality of GOPs are set as new units in the same manner as in the fourth embodiment. Indicates the data array state before overwriting. Also, for the sake of explanation, the present embodiment will be described using two GOPs as a unit.

In the figure, reference numeral 212 denotes GOP header information, which includes the picture header of the I picture data 213 of the first GOP. 213 is the I picture data of the first GOP, 214 is the P picture data of the first GOP, 215 is the I picture data of the second GOP, 216 is the P picture data of the second GOP, and 217 is the first GOP B1 picture data 218, B3 picture data of the first GOP, 219 B5 picture data of the first GOP, 220 B1 picture data of the second GOP, 221 B3 picture data of the second GOP, 222 Is B5 picture data of the second GOP, 223 is B2 picture data of the first GOP, 224 is B4 picture data of the first GOP, 225 is B6 picture data of the first GOP, and 226 is B2 picture data of the first GOP. B2 picture data 227 is B4 picture data of the second GOP, and 228 is B6 picture data of the second GOP. 229 is a P picture header of the first GOP, 230 is an I picture header of the second GOP, 231 is a P picture header of the second GOP, 232 and 234 are B picture headers of the first GOP, 233 and Reference numeral 235 denotes a B picture header of the second GOP. The range from the B picture header 234 of the first GOP to the B6 picture data 228 of the second GOP is set as the overwriting range.

In the present embodiment, such a data array is configured by rearrangement by the format encoder 110 and the buffer memory 109 as in the fifth embodiment. Then, B2, B4 and B6 in the first and second GOP data are overwritten based on the headers 234 and 235. In this case as well, one of the three playback screens is deleted, so that the image quality is degraded. However, since this screen is a GOP with little movement, the viewer is not bothered. It will be. In this manner, in the present embodiment, a predetermined recording time can be easily secured even if the recordable area is insufficient under the variable rate.

Further, in the present embodiment, since two GOPs are set as a new one-unit GOP, data continuity can be provided in a larger data area. It is possible to reduce the rotation waiting time of the optical disc, the number of track jumps of the optical head, and the number of data searches to half that in the fifth embodiment in units of 1 GOP. However, in the present embodiment, format conversion and inverse conversion are performed using a plurality of GOPs as one unit, so that a large-capacity buffer memory for storing data is required. Therefore, it is similar to the fourth embodiment that it is appropriate to set about several GOPs as one unit.

In the present invention described above, when the recordable area is insufficient due to the use of the variable rate and the predetermined recording time is insufficient, the predetermined recording time is reduced by overwriting the already recorded area. It is intended to secure the recording time, but by applying such a configuration of the present invention to an optical disk recording / reproducing apparatus employing a fixed rate, the recording time can be extended correspondingly.

According to the present invention, it is possible to easily secure a predetermined recording time even if the recordable area is insufficient at a variable rate.

According to another optical disc of the present invention, the header of the video information block has the address of the video information block, the time code describing the elapsed time from the start of recording or the start of the movie, or the time in the video information block. The I / P / B picture arrangement structure and the overwritable flag indicating whether or not overwriting is possible are recorded, so that long-time recording can be performed by overwriting and continuous playback of overwritten data and special playback / search are easy. Can be done.

According to another recording method of the present invention, when recording data on an optical disc, a recordable empty area on the optical disc is recorded based on the address of the last recorded last video information block on the optical disc to be recorded. Calculate, display on the screen as the remaining time, and allow the user to select whether or not to overwrite recording according to the user's selection, so overwriting the user himself and giving priority to the recording time even if a little image quality deterioration is prepared, or It is possible to have the user select whether to overwrite with priority given to image quality.

FIG. 2 is a block diagram illustrating a configuration of a recording system of the optical disc device according to the first embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of a reproduction system of the optical disc device according to the first embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of a decoder of the optical disc device according to the first embodiment of the present invention. FIG. 3 is a diagram showing a data structure of a digital video signal according to the first embodiment of the present invention. FIG. 3 is a conceptual diagram showing a concept of data overwriting by the optical disc device according to the first embodiment of the present invention in a time-series manner. FIG. 3 is a diagram showing a data recording state overwritten by the optical disc device according to the first embodiment of the present invention. FIG. 9 is a block diagram illustrating a configuration of a recording system of the optical disc device according to the second embodiment of the present invention. FIG. 9 is a diagram showing a data arrangement structure of a digital video signal according to a second embodiment of the present invention. 9 is a flowchart illustrating an operation sequence of the optical disc device according to the second embodiment of the present invention. 13 is a flowchart illustrating an operation sequence when an overwrite mode is selected in the optical disc device according to the second embodiment of the present invention. 13 is a flowchart illustrating an operation sequence when the normal recording mode is selected in the optical disc device according to the second embodiment of the present invention. FIG. 7 is a conceptual diagram showing a concept of overwriting by an optical disc device according to a second embodiment of the present invention. FIG. 9 is a diagram illustrating a recording state of data overwritten by the optical disc device according to the second embodiment of the present invention. FIG. 9 is a diagram showing a data arrangement structure of the optical disc device according to the third embodiment of the present invention and a recording state of overwritten data. FIG. 14 is a diagram illustrating a data arrangement structure of an optical disc device according to a fourth embodiment of the present invention and a recording state of overwritten data. FIG. 14 is a diagram showing a data arrangement structure of the optical disc device according to the fifth embodiment of the present invention. FIG. 17 is a diagram showing a data arrangement structure by the optical disc device according to the sixth embodiment of the present invention. FIG. 11 is a block diagram illustrating a configuration of a conventional optical disc device. FIG. 3 is a diagram illustrating a data structure of a conventional digital video signal. FIG. 3 is a diagram illustrating a concept of a GOP structure of a video signal to be recorded. FIG. 3 is a schematic diagram showing a ratio of a data amount per GOP to a recording area of an optical disc when performing recording at a variable rate. FIG. 4 is a comparison diagram comparing a case where recording is performed at a variable rate and a case where recording is performed at a fixed rate in a recording area of an optical disc. FIG. 14 is a diagram illustrating a data amount per GOP necessary to keep the image quality of a reproduced image constant regardless of the image. FIG. 4 is a diagram illustrating a data amount per GOP necessary to obtain a predetermined image quality, according to an image type.

Explanation of reference numerals

101: A / D converter, 102: motion detector, 103: DCT encoder, 104: adaptive quantizer, 105: inverse quantizer, 106: IDCT decoder, 107: frame memory, 108: variable Long encoding means, 109: buffer memory, 110: format encoder, 111: modulation means, 112: laser modulation means, 113: optical disk, 114: optical head, 115: feed motor, 116: disk motor, 117: servo circuit, 118: system controller, 119: reproduction amplifier, 120: header recognition means, 121: reproduction amplifier, 122: data detection and PLL circuit, 123: error correction means, 124: header detection / data division means, 125, 126: decoder, 127: variable length decoding means, 128: inverse quantization means, 129: I CT decoding means, 130: motion compensation means, 142: motion vector amount determining means.

Claims (3)

An I picture, which is two-dimensional compressed video data information compressed in a frame, a P picture, which is three-dimensional compressed video data information compressed by adding motion compensation by a temporally forward I picture, and Digital video data consisting of video information blocks containing mixed B-pictures, which are three-dimensional compressed video data information-compressed by adding motion compensation by forward or backward I-pictures or P-pictures, is recorded on a recording area of a disk-shaped recording medium. A recording method for recording in
A recording method for a disk-shaped recording medium, wherein a part or all of the B picture of the video information block is recorded. In the video information block, a time code indicating a recording time is recorded at a head side of the I, P, and B pictures,
2. The disk-shaped recording medium according to claim 1, wherein a part or all of the B picture of the video information block is reduced based on a remaining recording time calculated based on the time code information. Recording method. 3. The recording method according to claim 1, wherein the reduction of part or all of the B picture of the video information block is performed based on a motion amount of the video information block.

Images