JP2004140679A - Recording medium and its reproducer and recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly conduct a fast forward reproduction mode as well as normal reproduction and to obtain a good fast forward reproduced video. <P>SOLUTION: A recording medium 1 records video/sound data for normal reproduction on a data recording region 2 for normal reproduction and recording position information for controlling the recording position of the TS (Time Slot) packet of the video/sound data for normal reproduction on a normal reproduction data position recording region 4. The video/sound data for normal reproduction are reproduced from the recording region 2 based on the recording position information in a normal reproduction mode. In addition, a fast forward reproduction data recording region 3 is provided. The recording region 3 records video data for fast forward reproduction for the video/sound data as the normal reproduction independent of the video/sound data for normal reproduction. The video data for fast forward reproduction are reproduced based on the recording position information recorded on the fast forward reproduction data position recording region 5 in a fast forward reproduction mode. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a device for recording and reproducing video and audio information on a recording medium such as a digital video disk, and more particularly to a recording medium for fast-forward reproduction faster than a normal reproduction speed, a reproduction device and a recording device.
[0002]
[Prior art]
Digital video disk devices represented by DVDs have been put to practical use. In such a digital video disk device, image data is digitally compressed and encoded by using a digital image compression technique such as the MPEG2 system, recorded on a recording medium, and reproduced.
[0003]
In the MPEG2 system, images of a plurality of frames are grouped in units called GOPs (Group of Pictures), and each frame image in the GOP is compressed in a frame (I picture), forward predicted compressed image (P picture), bidirectional A compression process is performed on a predicted compressed image (B picture).
[0004]
An I picture is compressed using only one frame image. The P picture is compressed using a difference from a previous (past) image. The B picture is compressed using the difference between the preceding and following (past and future) images. Therefore, the entire frame image can be restored by itself from the I picture, but the P picture or B picture cannot restore the frame image by itself, but requires the preceding and following frame image data. .
[0005]
At the time of fast-forward playback, the pictures in the video data are thinned out and played back, thereby apparently increasing the screen update speed. At this time, the picture to be reproduced and displayed is an I picture (see Patent Document 1).
[0006]
[Patent Document 1]
JP-A-8-235833 (paragraph number [0028])
[0007]
[Problems to be solved by the invention]
When the above-described data reproducing method is performed during fast-forward reproduction, the following problems occur.
[0008]
That is, when performing fast-forward playback, only the I picture in the stream of image data is extracted and displayed on the screen. However, this method has a drawback that smooth image playback cannot be performed.
[0009]
Because, in general, an I picture has a larger data amount than other pictures (P picture, B picture). Therefore, if only I pictures are continuously played back, the number of pictures that can be read from the drive during fast-forward playback and the number of decoders Reduces the number of pictures that can be decoded. As a result, the number of screens displayed per unit time is reduced, and smooth screen reproduction cannot be performed.
[0010]
Further, the data amount of the I picture greatly changes depending on the image. For example, in a fast-moving image, the data amount of an I picture or a P picture tends to be small, and the data amount of a B picture tends to be large. In a fine-grained image, the data amount of the I picture is large. As described above, the data amount greatly varies depending on the content of the image. However, if the data amount of the I-picture greatly varies, the data reading time varies, and the screen display interval is not constant. The screen looks unnatural.
[0011]
Further, in the fast-forward playback as described above, unlike the normal playback, the playback head must be moved to the recording position of the I picture on the disc to play back the I picture data. If there is a variation in the recording position, the recording position is not regular, the access control to the recording position of the I picture on the disk becomes complicated, and the load on the mechanism increases.
[0012]
Furthermore, it is difficult to output audio information during fast-forward playback.
[0013]
SUMMARY OF THE INVENTION An object of the present invention is to provide a recording medium, a reproducing apparatus, and a recording apparatus capable of solving such a problem, performing a fast-forward playback operation smoothly with normal playback, and obtaining a good fast-forward playback image. To provide.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a recording medium for recording digital image-compressed video data, the first video data for normal reproduction generated by performing a digital image compression process on a video, This video is time-axis-compressed and further recorded with fast-forward playback second video data generated by digital image compression processing.
[0015]
The present invention is also a reproducing apparatus for reproducing data from the recording medium, wherein a normal reproducing mode and a fast-forward reproducing mode can be selected, and in the normal reproducing mode, the first video data is reproduced. In the fast forward reproduction mode, the second video data is reproduced.
[0016]
Further, the present invention is a recording apparatus for recording digital image compressed video data on the recording medium, wherein the first video data generating means for generating the first video data, and the second video data Second video data generating means for generating the first video data generated by the first video data generating means and the second video data generated by the second video data generating means on the recording medium. Recording means for recording the information.
[0017]
Further, the present invention is a recording apparatus for recording digital image compressed video data on the recording medium, wherein the video data generating means for generating the first video data and the video data generated by the video data generating means. Video data conversion means for converting one video data into the second video data, and the first video data generated by the video data generation means on the recording medium and the second video generated by the video data conversion means Recording means for recording data.
[0018]
Further, the present invention is a recording apparatus for recording digital image-compressed video data on the above-mentioned recording medium, comprising: an encoder for compressing the video into a digital image; A first block data generator for converting the video data for normal reproduction into video data; a time axis compressing means for compressing the digital image compressed video data from the engorder on a time axis; A second block data generating unit for converting the video data for fast-forward reproduction into TS, the video data for normal reproduction as the first video data, and the video data for fast-forward reproduction as the second video data on the recording medium. And recording means for recording the respective video data.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a view showing an embodiment of a recording medium according to the present invention, wherein 1 is a recording medium, 2 is a normal reproduction data recording area, 3 is a fast-forward reproduction data recording area, 4 is a normal reproduction data position recording area, and 5 is a normal reproduction data position recording area. Is a fast-forward reproduction data position recording area, and 6 is a management information recording area.
[0020]
In FIG. 1, a recording medium 1 is, for example, an optical disk, and a management information recording area 6 for recording file management information in order from the inner diameter side, and a normal playback video including normal playback video data and audio data. / Normal reproduction data position recording area for recording recording position information of audio data 4, Fast-forward reproduction data position recording area for recording recording position information of video data for fast-forward reproduction (which may include audio data) 5, for normal reproduction A normal reproduction data recording area 2 for recording video / audio data and a fast-forward reproduction data recording area 3 for recording video data for fast-forward reproduction are set. Note that the order does not always follow.
[0021]
In the normal reproduction data recording area 2 of the video / audio data for normal reproduction, image / audio information that has been compression-encoded by digital image compression-encoding processing is recorded. Here, the digital image compression / encoding processing method is based on the MPEG2 method, and the compression-encoded data is formed by sequentially forming packets by adding additional information for every 188 bytes of the data and forming a sequence of such packets. It shall be recorded as an MPEG transport stream (hereinafter, MPEG-TS).
[0022]
A stream of video data (ie, video data for normal reproduction) of the video / audio data for normal reproduction is generated by digital image compression encoding of an image of 30 frames per second according to the MPEG2 system. The video stream generated in this way is converted into an MPEG-TS consisting of a series of packets of 188 bytes in sequence and then recorded as a file in the normal reproduction data recording area 2 on the disc 100 together with additional information such as a time stamp. Is done. The packet to which the additional information is added in this manner is hereinafter referred to as a TS packet.
[0023]
FIG. 2 is a diagram showing an image of a block when an MPEG-TS TS packet is recorded on a sector, where 7 is a TS packet, 8 is packet data, and 9 is an MPEG-TS time stamp.
[0024]
In the figure, a 188-byte MPEG-TS TS packet 7 has 188 bytes of digital image compression-encoded video data as packet data 8 and a 4-byte (32-bit) time stamp 9 added thereto. This is a 192 byte packet. The time stamp 9 indicates a timing at which the TS packet 7 is output, and is a time measured by a 27 MHz clock. By controlling the output timing of each packet using the time stamp 9, data can be output at the same interval as the packet interval at the time of input.
[0025]
Each of the 192-byte TS packets 7 to which the time stamp 9 is added is recorded in a predetermined sector on the optical disk 101 in FIG. Since 2048-byte data can be written in a sector on the optical disk 1, data for 64 packets (= 2048 × 6/192) can be recorded in an area of 6 sectors. By using this condition (ie, the TS packet number in each sector is determined), the sector position can be determined from the packet number. For this purpose, on the optical disc 1, a stream of normal reproduction video data is recorded in the normal reproduction data recording area 2, and at the same time, position information (recording of normal reproduction video data) indicating the recording position of each packet of the normal reproduction video data is performed. Recording position information) is recorded in the normal reproduction data position recording area 4 using a packet number or the like.
[0026]
FIG. 3 is a diagram schematically showing a specific example of the recording position information of the normal reproduction video data.
[0027]
In this figure, the normal reproduction video data recording position information associates the display time of each picture with the packet number of the first TS packet of each picture.
[0028]
Each display time of a picture represents a time indicating the start of display of a sequential frame. The display time of the first frame is set to 0, the display time of the next second frame is set to 1/30. Since it is seconds, 1/30 = 0.033 seconds. The display time of the n-th (n = 1, 2, 3,...) frame is determined by the number of frames n of the picture and the frame period T _F , Ie, (n−1) × T _F Can be obtained from For example, the display time of the picture of the 1000th frame from the top is 33.30 seconds based on 999 × 1/30.
[0029]
On the other hand, the packet number as the recording position information of the video data for normal reproduction indicates the packet number of the TS packet at the start of each frame. Here, the first frame starting at 0.000 seconds is an I picture, and its registered packet number is 0. This represents the first TS packet. The second frame starting at 0.033 seconds is a B picture, for which the packet number is 26595. This represents the first TS packet of the second frame. Therefore, the first frame, the I picture, is composed of 26595 TS packets with packet numbers 0 to 26594. The third frame starting at 0.066 seconds is also a B picture, and its packet number is 28811. This represents the first TS packet of the third frame. Therefore, the B-frame, which is the second frame, is composed of 2217 TS packets with packet numbers 26595 to 28811. Similarly, the B frame of the third frame is composed of 2217 TS packets of packet numbers 28811 to 31027, and the fourth frame is a P picture, and is composed of 4433 TS packets of packet numbers 31027 to 35459. Has become.
[0030]
The recording positions of these TS packets can be easily obtained by counting the number of packets from the start of recording the first frame of MPEG-TS.
[0031]
At the time of reproducing the normal reproduction video / audio data (normal reproduction mode), by utilizing the recording position information of the normal reproduction video data recorded in the normal reproduction data position recording area 4, any arbitrary data on the MPEG-TS can be obtained. Reproduction can be performed from the picture at the time. Specifically, a packet number corresponding to the display time at which reproduction is desired to be started is obtained from the recording position information of the video data for normal reproduction, and a sector number in which the TS packet of this packet number is recorded is obtained from the obtained packet number. Then, data is read from the sector of this sector number on the optical disk to perform a reproducing operation.
[0032]
For example, assuming that the TS packet with the packet number 0 is recorded at the beginning of the sector with the sector number 0, 64 TS packets from the packet numbers 0 to 63 are described in the six sectors with the sector numbers 0 to 5. In the same manner, 64 TS packets are sequentially recorded in 6 sectors in the same manner. Then, the packet number of the TS packet recorded in each sector is determined. From this, when the time at which the display is to be started is determined, the sector number and, accordingly, the reproduction start position on the optical disk 1 are determined. Become.
[0033]
As will be described later, in the recording position information of the video / audio data for normal reproduction, a flag may be set for the frame of the I picture so that the recording position of the frame of the I picture can be detected. In this case, when the reproduction start position is specified by the user, and when the frame at the reproduction start position is not an I picture, the position of the I picture closest to the specified reproduction start position is detected from this flag. Reproduction can be started from an I picture.
[0034]
Next, recording of video data for fast-forward playback will be described.
[0035]
In FIG. 1, a fast-forward playback data recording area 3 is provided on a recording medium 1 separately from the above-described normal playback video / audio data, and fast-forward playback video data is recorded in this area.
[0036]
The fast-forward playback video data is data generated by imitating a video displayed when the original video is fast-forwarded. Specifically, the time axis of the video data for normal reproduction is reduced by a ratio corresponding to the magnification of the fast-forward reproduction, and is generated by performing an encoding process. For example, in the case of video data for fast forward reproduction at 30 times speed, video data for every 30 frames of video data for normal reproduction is extracted, and digital video compression encoding is performed on the video data to obtain video data for fast forward reproduction. . In this case, the display interval of the extracted 30 frames is set to 1/30 second, which is the same as that of the video of normal reproduction. As a result, at the time of reproduction, frame images displayed at intervals of 30 × 1/30 = 1 second in normal reproduction are continuously output and displayed at time intervals of 1/30 seconds. The video appears to be updated at 30x speed.
[0037]
Here, the video data for fast-forward playback may have a GOP structure like the MPEG2 stream for normal playback. This facilitates decoding (decompression decoding) processing by the decoder, and does not require special consideration even when an external decoder is used.
[0038]
Such fast-forward playback video data is recorded as a file in the fast-forward playback data recording area 3 of the fast-forward playback video data on the optical disc 1.
[0039]
The video data for fast-forward playback generated by the above-described digital video compression encoding process is sequentially converted into a TS packet structure having a predetermined length of 188 bytes, and a time stamp indicating the output time of the TS packet is added. It is recorded in the corresponding sector in the fast-forward reproduction data recording area 3 above. The recording method of the video data for fast-forward reproduction may be the same as the recording method of the video data for normal reproduction described with reference to FIG.
[0040]
For the fast-forward playback video data, the TS packet of the fast-forward playback video data is recorded, and the recording position information is generated and recorded in the fast-forward playback data position recording area 5 on the disk 100. The recording position information of the video data for fast-forward reproduction has the same configuration as the recording position information of the video data for normal reproduction shown in FIG. 3, and the display time of each picture is also changed at a predetermined cycle from the video data for normal reproduction. The video data for fast-forward reproduction in which the extracted frames are continuous are obtained in the same manner as the video data for normal reproduction. Therefore, if the recording position information in FIG. 3 is described with respect to video data for fast-forward playback, the display time of the first frame is 0.000 seconds, the display time of the next second frame is 0.033 seconds,... …It turns out that. Also, the packet numbers are the packet number of the first TS packet of the first frame, the packet number of the first TS packet of the second frame, and so on, respectively.
[0041]
As described above, the video / audio data for normal reproduction and the video data for fast-forwarding are recorded in the above-mentioned predetermined area of the optical disc 1 together with the recording position information corresponding thereto.
[0042]
Each of the video data and its recording position information is handled as an independent file so that reading from the optical disc 1 is facilitated. For this purpose, a file identifier (file name) is assigned to each file. Further, additional information such as the recording sector position, data length (number of bytes), and recording time of each file on the optical disk 1 is collectively managed. These pieces of information are recorded as file management information in a predetermined position on the optical disk 1, that is, in the management information recording area 6. When reading video data from the optical disk 1, each file (that is, the above-described recording position information) is read with reference to the file management information.
[0043]
In the above description, video data for fast-forward playback is described as data other than video / audio data for normal playback. Of course, the same applies to other playback such as rewind playback (fast-forward playback in the reverse direction). It goes without saying that it is possible.
[0044]
Also, the video data for fast-forward playback can include audio information as needed. In this case, as for the audio information, the audio for normal reproduction is, for example, audio data encoded by a predetermined digital audio compression encoding process by shortening the time axis so as to have a reproduction speed of 30 times, and What is necessary is just to record with data.
[0045]
It should be noted that the above-described video data for fast-forward playback is different from a normal MPEG-TS stream, and can be composed of only I pictures. In the case of a stream consisting of only I pictures, there is an advantage that all pictures can be reproduced regardless of which picture is reproduced. However, if a stream is generated using only I-pictures, the amount of data becomes large. Therefore, it is necessary to reduce the amount of data by increasing the video compression rate.
[0046]
The video data for fast-forward reproduction is different from the video data for normal reproduction, and need not always be video data of 30 frames per second. For example, by setting the display time of one picture to 1/15 second or the like, the number of pictures of the video data for fast-forward playback to be recorded can be reduced, and the capacity of the video data for fast-forward playback can be reduced.
[0047]
Next, a reproducing apparatus for the above recording medium will be described.
[0048]
FIG. 4 is a block diagram showing an embodiment of a reproducing apparatus according to the present invention for reproducing data from the recording medium 1 shown in FIG. 1, wherein 10 is a reproducing apparatus, 11 is a disk drive, 12 is a control microcomputer, and 13 is a packet. An extracting unit, 14 is a decoder, and 15 is a monitor television.
[0049]
First, a normal reproduction operation will be described.
[0050]
In FIG. 1, when an optical disk 1 is inserted into a disk drive 11 by a user, a control microcomputer 12 reads out file management information recorded in a management information recording area 6 (FIG. 1) on the optical disk 1, and Obtain information such as the file type and file size recorded above.
[0051]
On the optical disk 1, as described with reference to FIG. 1, a data file of video / audio data for normal reproduction (video data file for normal reproduction) is stored in a normal reproduction data recording area 2, and a fast forward reproduction data is recorded in a fast forward reproduction data recording area 3. The data file of the video data for fast-forward (data file for fast-forward playback) has a data file of the recording position information of the video / audio data for normal playback (the data-position information file for normal playback) in the normal playback data position recording area 4, and the fast forward playback. A data file (data position information file for fast-forward playback) of the recording position information of the video data for fast-forward playback is recorded in the data position recording area 5, and the data file is read from the management information recording area 6 by a file identifier in the file management information. These files are determined.
[0052]
When a user instructs a normal reproduction mode for reproducing video / audio data for normal reproduction with a remote controller (not shown) or the like, the control microcomputer 12 instructs the disk drive 11 to perform normal reproduction from the normal reproduction data recording area 2. Instruction for reading the video / audio data file. Thereby, the video / audio data for normal reproduction read from the optical disk 1 in the disk drive 11 is supplied to the packet extracting unit 13, and the TS packet 7 of MPEG-TS (FIG. ) Is extracted. Each of the extracted TS packets 7 is supplied to the decoder circuit 14 at a timing corresponding to the time stamp 9 (FIG. 2) added thereto, and the packet data 8 (FIG. 2) is decoded and compression-coded. Video information and audio information can be obtained. These video information and audio information are further decompressed and decoded, converted into analog information, and supplied to the monitor television 15.
[0053]
Here, the TS packet of the MPEG-TS contains information (PCR (Program Clock Reference)) indicating the playback time of the stream, and the playback time of the current stream is obtained by referring to this time information. be able to. Of course, since the packet number of the recording position information 9 (FIG. 2) of the TS packet to be reproduced can be determined, the time of the stream being reproduced can be obtained from the time information and the recording position information.
[0054]
Next, when fast-forward playback is instructed by the remote controller during the normal playback mode, the control microcomputer 12 stops playback in the normal playback data recording area 2 and stops in the fast-forward playback data recording area 3 (FIG. 1). A fast-forward playback mode for playing back is started. This starts the reproduction of the video data for fast-forward playback. At this time, the playback start time of the video data for fast-forward playback is a display corresponding to the display time at the end of the playback operation of the video / audio data for normal playback. Time. This is to allow the normal playback video based on the video data for normal playback that has been played so far to be directly transferred to the fast-forward playback of the video data according to the fast-forward playback instruction. Subsequent to fast-forward playback will be continuous in content.
[0055]
To execute this, the display time at the start of playback of the video data for fast-forward playback is a value obtained by dividing the last display time by the fast-forward playback instruction of the video data for normal playback by the magnification of the video data for fast-forward playback. And For example, if it is assumed that the reproduction of the video data for normal reproduction has been performed for 10 minutes (= 600 seconds) and a fast-forward reproduction instruction has been issued, for example, the fast-forward reproduction is 30 times the normal reproduction (that is, the magnification is 30 times). , 600 seconds / 30 = 20 seconds is the display time at the start of the playback of the video data for fast-forward playback, and the video data for fast-forward playback is played back from the frame at the display time of 20 seconds (ie, the frame 20 seconds after the beginning). That's all we need to do.
[0056]
The position in the fast-forward playback data recording area 3 of the optical disc 1 where the frame 20 seconds after the head of the fast-forward playback data is recorded is determined by the recording of the playback video data recorded in the fast-forward playback data position recording area 5. The position can be detected from the position information, and by referring to the packet number corresponding to the display time 20 seconds of the recording position information, the position of the TS packet in which the 20-second frame is recorded can be determined.
[0057]
In the fast-forward playback mode, the video data for fast-forward playback is sequentially played back from the TS packet recording position in the fast-forward playback data recording area 3 obtained in this manner (in this case, audio information may be included). . At this time, since the time axis of the fast-forward playback video data is already compressed at the time of recording as described above, there is no need to perform special processing for fast-forward playback, and the fast-forward playback video data is played back as usual. Just by doing so, it is possible to display a fast-forward video as if it were playing fast forward.
[0058]
When the normal playback mode is instructed by the remote controller during the fast-forward playback mode, the mode shifts from the fast-forward playback mode to the normal playback mode. At this time, the reproduction time (display time) of the video / audio data for normal reproduction is calculated from the reproduction time (display time) at the time when this instruction of the video data for fast-forward reproduction is given, and the frame of the display time obtained as a result is calculated. Then, the reproduction of the normal reproduction data recording area 2 (FIG. 1) may be started. In this case, the display time at the start of the playback of the video / audio data for normal playback is opposite to the switching from the normal playback mode to the fast-forward playback mode, and is opposite to the display time of the last frame of the video data for fast-forward playback. What is necessary is just to multiply the magnification. For example, if the magnification is 30 and the last frame of the video data for fast-forward playback is 30 seconds, the display time of the frame at the start of the playback of the video data for normal playback is 30 seconds × 30 = 900 seconds ( 15 minutes). As a result, the contents continuously shift from the fast-forward playback mode to the normal playback mode.
[0059]
For the video / audio data for normal reproduction, a recording position information file indicating the relationship between the frame and the packet number is recorded in the normal reproduction data position recording area 4, and from the display time obtained as described above, From this recording position information, it is possible to determine the recording position of the TS packet that starts the reproduction of the normal reproduction video / audio data in the normal reproduction data recording area 2.
[0060]
Accordingly, reproduction is started from the position of the TS packet at the start of reproduction of the video / audio data for normal reproduction obtained in this manner, reproduced, the TS packet is extracted by the packet extraction unit 13, and further decoded, Normal playback can be performed continuously from the scene where fast-forward playback has been completed.
[0061]
As described above, by using the optical disc 1 shown in FIG. 1 for the reproducing apparatus 10 shown in FIG. 4, it is possible to easily and smoothly switch between normal reproduction and fast-forward reproduction. Can be displayed as changing.
[0062]
Here, in the reproducing apparatus 10 shown in FIG. 4, the magnification of the fast forward reproduction is set to 30 times (that is, 30 times speed), but the present invention is not limited to this. For example, even if video data for fast-forward playback with a magnification of 30 is recorded, in the fast-forward playback mode, control is performed so that frames to be played are displayed twice each, resulting in the same as fast-forward playback at 15x speed. An effect can be obtained, and furthermore, a frame to be reproduced is arbitrarily switched two or more times so that it can be repeatedly displayed, whereby a plurality of different double-speed fast-forward reproductions can be performed.
[0063]
Also, by reversing the display order of the frames of the video data for fast-forward playback, it is possible to support rewind playback.
[0064]
In the embodiment shown in FIG. 4, the magnification of the fast-forward reproduction is set to 30 times (that is, 30 times speed). However, this is shown as an example for convenience of explanation, and the present invention is not limited to this. However, it is possible to realize a fast-forward playback mode with an arbitrary playback magnification. For example, fast-forward playback data of different playback magnifications such as 5 ×, 10 ×, and 30 × speeds are separately recorded, and the fast-forward playback data to be played back is switched in accordance with a user's instruction. It is possible to cope with the fast-forward playback mode, and it is possible to smoothly perform mode switching at each magnification of the fast-forward mode. In addition, even when switching the magnification in the fast-forward mode, by calculating the reproduction start position according to each magnification, the magnification of the mode can be switched without interruption of the reproduced video.
[0065]
FIG. 5 is a block diagram showing an embodiment of a recording apparatus according to the present invention for recording data on the recording medium 1 as described with reference to FIG. 1, wherein 16 is a recording apparatus, 17 is an input terminal, and 18 is for normal reproduction. An encoder 19 is an encoder for fast-forward reproduction, 20 and 21 are block data generators, 22 and 23 are buffer memories, 24 is a control microcomputer, and 25 is a disk drive.
[0066]
In the figure, a video signal and an audio signal input from an input terminal 17 are supplied to an encoder 18 for normal reproduction and an encoder 19 for fast-forward reproduction.
[0067]
In the normal reproduction encoder 18, the video signal and the audio signal are digitized, the video data is image-compressed and encoded by a predetermined encoding process, and the audio data is also audio-compressed and encoded by a predetermined encoding process. The compression-encoded video data and audio data are supplied to the block data generation unit 20 and divided into 188-byte blocks, and each block is added with a header such as a time stamp to be converted into a TS packet. Then, these audio and video TS packets are multiplexed, and further multiplexed with other audio and video data TS packets to generate an MPEG-TS of video / audio data for normal reproduction. The video / audio data for normal reproduction is stored in the buffer memory 22.
[0068]
The control microcomputer 24 sequentially checks the capacity of the video / audio data for normal reproduction stored in the buffer memory 22, and when the data exceeds a predetermined capacity, the disk mounted on the disk drive 25. 1 is written. Specifically, the control microcomputer 24 outputs a write command to the disk drive 25, and instructs writing from a predetermined sector in the normal reproduction data recording area 2 of the optical disk 1 shown in FIG. Thus, the MPEG-TS of the video / audio data for normal reproduction read from the buffer memory 22 is supplied to the disk drive 25 as write data, and writing is performed from this predetermined sector.
[0069]
Further, in parallel with the recording processing of the video / audio data for normal reproduction, video data for fast-forward reproduction is also generated.
[0070]
That is, the same video signal as described above input from the input terminal 17 and supplied to the fast-forward playback encoder 19 is extracted and digitized one by one for each of a plurality of frames at a ratio corresponding to the magnification of the fast-forward playback, and is digitized on the time axis. Are compressed into continuous video data, and then subjected to digital compression encoding processing. When an audio signal is also recorded, the audio signal is compressed on the time axis by thinning out the audio signal at a similar magnification, and is subjected to a predetermined digital audio compression encoding process and encoded. In this case, the digital compression encoded video data may have a GOP structure of MPEG2, or may have a structure including only I pictures. However, in the case of a structure composed of only I pictures, the compression rate in the fast-forward playback encoder 19 is increased, and the data amount of the I picture is reduced as compared with the case of the video data for normal playback.
[0071]
When the compression-encoded video data and the audio signal are recorded, the compression-encoded audio data is further supplied to the block data generation unit 21 and is divided into blocks of 188 bytes, and each of the audio data is compressed. A TS packet is generated by adding a header such as a time stamp to the block. When recording audio data, the video data TS packet is multiplexed with the audio data TS packet, and further multiplexed with other video data and audio data TS packets for fast-forward playback. MPEG-TS of the video data for fast-forward playback is generated (for example, when audio data is also recorded, a TS packet of the audio data is included). The video data for fast-forward reproduction is stored in the buffer memory 23.
[0072]
The buffer memories 22 and 23 may be the same buffer memory. In this case, a normal reproduction area for storing normal reproduction video / audio data and a fast-forward reproduction area for storing reproduction video data in this buffer memory. Are provided.
[0073]
As described above, the fast-forward playback video data is a frame in which intermittent frames obtained by extracting the input video signal that is the source of the normal playback video data at a ratio corresponding to the fast-forward playback magnification are continuously arranged. It is generated from a time-domain converted signal of a column of video signals. The time stamp added to the video signal by the block data generation unit 21 for each TS packet represents the real time of the video signal that has been time-axis converted in this way. Therefore, for example, when the above-described time-base compression conversion is to extract one frame at a time for every 30 frames of the input video signal and convert these extracted frames into a video signal that is temporally continuous, The cycle is 1/30 second. Therefore, the time stamp added to the TS packet differs by 1/30 second for each frame.
[0074]
The control microcomputer 24 also sequentially checks the capacity of the video data for fast-forward playback stored in the buffer memory 23, and if the data exceeds a predetermined capacity, the data is transferred to the disk 1 mounted on the disk drive 25. Is written. Specifically, the control microcomputer 24 outputs a write command to the disk drive 25 to instruct writing from a predetermined sector in the fast-forward reproduction data recording area 3 of the optical disk 1 shown in FIG. As a result, the MPEG-TS of the video data for fast-forward playback read from the buffer memory 23 is supplied as write data to the disk drive 25, and writing is performed from this predetermined sector.
[0075]
Here, the control microcomputer 24 writes the video / audio data for normal reproduction in the buffer memory 22 and the video data for fast-forward reproduction in the buffer memory 23 to the optical disc 1. The writing is performed by time division processing. Do.
[0076]
The control microcomputer 24 counts the TS packets of the video data for normal reproduction and the audio data each time the TS packets are recorded on the optical disc 1, and sets the count value in the TS packet at the start of each frame as a packet number. With the time stamp added to the TS packet as the display time, as shown in FIG. 3, the recording position information of the video / audio data for normal reproduction that associates the display time and the packet number at the start of each frame. It is created and recorded in the normal reproduction data position recording area 4 (FIG. 1) of the optical disk 1. The same applies to the video data for fast-forward playback (which may include audio data). Each time the first TS packet of each frame is recorded, the packet number and the display time are obtained. The recording position information as shown is created and recorded in the fast-forward reproduction data position recording area 5 (FIG. 1) of the optical disk 1. Such recording position information may be such that the first TS packet of each frame is recorded and an information portion corresponding to this TS packet is recorded. However, video / audio data for normal reproduction and video for fast-forward reproduction may be recorded. After the data recording is completed, the entire data may be recorded simultaneously.
[0077]
Thus, predetermined information can be recorded in each of the areas 2 to 5 of the optical disk shown in FIG.
[0078]
When the recording position information is created, each time the normal reproduction encoder 18 or the fast-forward reproduction encoder 19 starts to supply the compression-coded video data of a new frame (picture) to the block data generation units 20 and 21, the fact is notified. The indicated information is supplied to the control microcomputer 24, whereby the control microcomputer 24 acquires the time stamp added to the first TS packet of each frame from the block generation units 20 and 21. Further, when the normal reproduction encoders 18 and 19 start supplying the compressed and coded image data of the I picture to the block data generation unit 20, they also supply data indicating the fact to the control microcomputer 24. Thus, the control microcomputer 24 obtains the time stamp added to the first TS packet of each frame of the video data for normal reproduction and the video data for fast-forward reproduction from the block generation unit 20, and when the frame is an I-picture frame, , A flag indicating that the picture is an I picture is set in the time stamp corresponding to the picture. In the case of fast-forward playback data consisting of only I pictures, such a flag is not necessary.
[0079]
When the time stamp is acquired in this manner, the control microcomputer 24 checks the time stamp added thereto and the acquired time stamp for each TS packet read from the buffer memories 22 and 23, and compares the acquired time stamp with the acquired time stamp. When a TS packet to which a matching time stamp is added (this is the first TS packet of the frame) is recorded on the optical disc 1, this time stamp is used as a display time, and the count value of the TS packet at this time is used as a packet number and Create recording position information to be recorded. When an I picture flag is set in the obtained time stamp, the flag is added to the recording position information. Such a flag is not shown in FIG.
[0080]
Thereby, the recording position of the I picture of the normal reproduction video data recorded in the normal reproduction data recording area 2 of the optical disc 1 can be detected, and the I picture closest to the normal reproduction start position specified by the user (that is, the I picture) The reproduction from the closest I-picture before the specified normal reproduction start position or the closest I-picture after the specified normal reproduction start position becomes possible. When the reproduction is started from an arbitrary frame instead of the I picture, the I picture flag is not necessary. The same applies to the case where video data for fast-forward playback is played back from the fast-forward playback data recording area 3.
[0081]
In the above description, the normal reproduction video / audio data and the fast-forward reproduction video data are recorded simultaneously and in real time. However, the present invention is not limited to this. For example, the normal reproduction video / audio data May be recorded in real time, and thereafter, video data for fast-forward reproduction may be created and recorded from the video / audio data for normal reproduction. In this case, the recording of the video / audio data for normal reproduction is the same as described above, but the video data for fast-forward reproduction is, for example, one of the compression-encoded video data output from the normal reproduction encoder 18. The pictures are extracted at a ratio corresponding to the magnification of the fast-forward playback, and are sequentially stored in a memory (not shown). When the recording of the video / audio data for normal playback on the optical disc 1 is completed, the picture is compressed and encoded from an I picture. The read video data may be read out so that each frame is temporally continuous and supplied to the block generation unit 21, and the video data for fast-forward reproduction may be created and recorded on the optical disc as described above. Alternatively, instead of the normal playback encoder 18, only I-picture frames are extracted from the video / audio data for normal playback generated by the block data generator 20 at a ratio corresponding to the magnification of the fast-forward playback and stored in the memory. It may be stored and read out continuously, and the block data generation unit 21 may replace the time stamp of each TS packet with the time stamp for fast-forward playback. According to this, since it is not necessary to mount a plurality of encoders, the cost can be reduced.
[0082]
When the fast-forward playback video data is created from the normal-playback video data, the compression rate is also increased to increase the data amount of the I-picture, which is the fast-forward playback video data. For this purpose, digital video data that has been input is first taken into a memory such as a hard disk device, and is subjected to compression encoding processing for a sufficient time. Of course, when the video data for normal reproduction and the video data for fast-forward reproduction are generated independently, the compression rate of the video data for normal reproduction may be similarly increased to reduce the data amount. This can be used, for example, when ROMizing a video source such as a movie.
[0083]
Of course, there is no problem if the above-described digital video compression encoding process is all performed on a computer and only the finally completed data is recorded on the optical disc 1.
[0084]
Note that the recording format on the optical disc shown in FIG. 1 is an example, and if the normal reproduction data and the fast-forward reproduction data are recorded independently and can be reproduced, the above-described example is used. The recording method is not limited to the above method, and the recording method is not limited to the above method, and another method may be used. For example, the data for normal reproduction and the data for fast-forward reproduction may be multiplexed and recorded in the same recording area of the optical disc 1 by adding a code for identifying them to each TS packet. At the time of reproduction, either the data for normal reproduction or the data for fast-forward reproduction can be reproduced by identifying with such a code.
[0085]
In the above description, the recording medium is an optical disk. However, the present invention is not limited to this, and another type of recording medium such as a magnetic disk or a magneto-optical disk may be used.
[0086]
【The invention's effect】
As described above, according to the present invention, video data for fast-forward playback is also recorded together with video data for normal playback so that playback can be performed independently of the video data. Data can be continuously reproduced, the reproduction operation can be simplified, and processing such as conversion from a video for normal reproduction is not required, and smooth fast-forward reproduction can be performed.
According to the present invention, the video data for fast-forward playback can be generated independently of the video data for normal playback. And fast-forward reproduction at a desired magnification becomes possible.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a recording medium according to the present invention.
FIG. 2 is a diagram showing a structure of a TS packet to be recorded on the recording medium shown in FIG.
FIG. 3 is a diagram schematically showing a specific example of recording position information of a TS packet recorded on the recording medium shown in FIG.
FIG. 4 is a block diagram showing a specific example of a playback device according to the present invention.
FIG. 5 is a block diagram showing a specific example of a recording apparatus according to the present invention.
[Explanation of symbols]
1 Recording medium
2 Normal playback data recording area
3 Fast-forward playback data recording area
4 Normal playback data position recording area
5 Fast forward playback data position recording area
6 Management information recording area
7 TS packet 7
8 packet data
9 time stamp
10 Reproduction device
11 Disk drive
12 Control microcomputer
13 Packet extractor
14 Decoder
15 Monitor TV
16 Recording device
17 Input terminal
18 Normal playback encoder
19 Fast forward playback encoder
20, 21 block data generation unit
22, 23 buffer memory
24 Control microcomputer
25 disk drive

Claims (5)

A recording medium for recording digital image compressed video data,
First video data for normal reproduction generated by performing digital image compression processing on video, and second video data for fast forward reproduction generated by performing time-axis compression on the video and digital image compression processing A recording medium characterized by recording the following. A reproducing apparatus for reproducing data from the recording medium according to claim 1,
Normal playback mode and fast forward playback mode can be selected,
A reproducing apparatus for reproducing the first video data in the normal reproduction mode, and reproducing the second video data in the fast forward reproduction mode. A recording device that records digital image compressed video data on the recording medium according to claim 1,
First video data generating means for generating the first video data;
Second video data generating means for generating the second video data;
Recording means for recording the first video data generated by the first video data generation means and the second video data generated by the second video data generation means on the recording medium. Characteristic recording device. A recording device that records digital image compressed video data on the recording medium according to claim 1,
Video data generation means for generating the first video data;
Video data conversion means for converting the first video data generated by the video data generation means into the second video data;
A recording apparatus comprising: a recording unit that records the first video data generated by the video data generation unit and the second video data generated by the video data conversion unit on the recording medium. A recording device that records digital image compressed video data on the recording medium according to claim 1,
An encoder that compresses video into digital images,
A first block data generation unit that converts the digital image compressed video from the engorder into MPEG-TS normal reproduction video data;
Time axis compression means for time axis compressing the digital image compressed video data from the engorder,
A second block data generating unit for converting the video data from the time axis compression unit into video data for fast-forward playback of MPEG-TS;
Recording means for recording on the recording medium the video data for normal reproduction as the first video data and the video data for fast-forward reproduction as the second video data, respectively. .

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