JP3598540B2 - Magnetic recording / reproducing device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to, for example, a magnetic recording / reproducing apparatus used for image retrieval for retrieving recorded images.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a VTR, an image search for searching what kind of image is recorded on one tape is performed. In this case, unless a memo is recorded or a user manually inputs the data into an external storage device such as a database, a high-speed picture search for checking while viewing the reproduced image during fast-forwarding of the tape is performed. There was no other way but to do it.
[0003]
This is true for analog VTRs for home use, analog and digital VTRs for business use. Hereinafter, mainly a digital VTR for business use will be described. Although most VTRs already use a cassette tape, the term tape is used as a generic term to distinguish it from a disk medium.
[0004]
FIG. 9 is a block diagram showing a configuration of a digital VTR as a conventional magnetic recording / reproducing apparatus. In FIG. 9, at the time of recording, the analog input image signal supplied to the A / D converter 90 is converted into digital image data. The digital image data is supplied to the recording encoder 91, where necessary signal processing such as addition of an error correction code and shuffling is performed. The recording data subjected to the signal processing is supplied to a recording system circuit 92 of a recording / reproducing unit 99, amplified in a high frequency, and recorded on a tape 94 by a recording head 93.
[0005]
At the time of reproduction, reproduction data reproduced from the recorded tape 94 by the reproduction head and demodulated by the reproduction system circuit 96 are supplied to the reproduction decoder 97. In the reproduction decoder 97, the reproduction data undergoes necessary signal processing such as deshuffling and error correction, and is returned to the original image data. This image data is supplied to the D / A converter 98, converted into an analog output image signal, and output. The electrical and mechanical control of the entire digital VTR is performed by a system controller (not shown).
[0006]
In the case of a digital VTR that records such image data as it is, in a high-speed picture search for searching for an image, the pixel at a corresponding position on the display is updated based on the extracted data. It was possible to display a complete but identifiable image.
[0007]
In recent years, image compression technology using high-efficiency coding technology has remarkably advanced, and it has become possible to record at a data rate of 1/10 or less without significantly deteriorating image quality. The configuration of a digital VTR for compressing and recording an image is the same as that shown in FIG. 9. In FIG. 9, a function of compressing an image is added to a recording encoder 91, and image compression is decompressed by a reproduction decoder 97. The only difference is that an additional function is added.
[0008]
However, in the case of such a digital VTR using image compression, much of the data that can be extracted by a high-speed picture search does not correspond to independent pixels by itself, but has meaning when combined with data of peripheral pixels. It is data that you have. Therefore, it is difficult to display pixels that can be identified by a high-speed picture search unless the compression method and the data arrangement on the tape are devised.
[0009]
In such a conventional digital VTR, a high-speed picture search accompanied by image display has been regarded as an indispensable function. To realize this, restrictions are imposed on the tape format, the compression method or the compression ratio, and a necessary and sufficient Compression to the data rate was not allowed, and effective use of tapes was difficult.
[0010]
On the other hand, the most inconvenient point in a digital VTR used for program production in the field is that it takes too much time to fast-forward to a tape position where necessary pixels are recorded. In order to overcome this drawback, as a recent trend, development of an image editing machine using a hard disk or a workstation using a magneto-optical disk as a recording medium, which is characterized by good operability by random access, is progressing.
[0011]
FIG. 10 is a block diagram showing the configuration of an image recording apparatus using this workstation. In FIG. 10, necessary image data is accumulated on a hard disk of a hard disk drive circuit 102 via a digital VTR 101 with several tapes 100 recorded as sources. A magneto-optical disk may be used instead of the hard disk. Accordingly, necessary minimum data such as image data and indexes are stored in the semiconductor memory 103 in the workstation 106.
[0012]
When the program is edited using this, the editor displays the data in the semiconductor memory 103 on the display 105 of the workstation 106 and determines the editing procedure based on the data. According to the editing procedure, the image data is read from the hard disk of the hard disk drive circuit 102 and displayed on the display 105.
[0013]
By repeating such operations, the editing operation can be performed efficiently. The image recording apparatus using the workstation can take advantage of the feature of random access not only for editing but also for sending out programs such as news and commercials as programs of a relatively short time.
[0014]
However, it is considered that a digital VTR is used for the storage of the completed program for the time being. The reason is that, to date, there is no recording medium that is cheaper than a magnetic tape in consideration of the medium unit price per information. Accordingly, as shown in FIG. 10, the result of editing is recorded and stored on another tape again via the digital VTR.
[0015]
By the way, a helical scan VTR can realize recording and reproduction at a data rate of several hundred Mbps, while a hard disk and a magneto-optical disk can record and reproduce at a data rate of several tens Mbps at least at this stage. Can not be realized. Therefore, even if it is assumed that an image of the current NTSC system is handled, a digital VTR of a 4: 2: 2 D-1 format has a DMbps of 200 Mbps and a sampling frequency of 4fsc (14.31818 MHz) in a D-2 or D-3 format. Recording and reproduction at a data rate of 100 Mbps cannot be realized with a digital VTR.
[0016]
For this reason, an image compression technique is indispensable, and image data compressed in an allowable range in image quality is handled. However, even if the result of editing using the compressed image data is recorded and stored in a conventional high data rate digital VTR, the image quality cannot be obtained at the original data rate of the digital VTR. Degradation due to the compression performed at the time remains.
[0017]
Therefore, when a digital VTR intended for storage is considered on the premise of the presence of an editing machine using a workstation, it is considered that there is no need to record and reproduce at a high data rate as in the past. Conversely, considering that the data rate of a digital VTR that can be realized with current technology is several times higher than the data rate of a hard disk or a magneto-optical disk, image data having a data rate equivalent to that of a hard disk or a magneto-optical disk can be obtained. It is considered that a digital VTR in which the recording and reproduction time of one tape is remarkably lengthened by parallel recording is more desirable.
[0018]
In a digital VTR that records image data encoded at a high compression rate as described above, a high-speed picture search function for searching for an image is, as described above, large for a compression system and a signal processing circuit of a reproduction system. It is clear that it will be a burden. In addition, in the case of performing parallel recording by making the most of the capability of the digital VTR, a discriminable image is displayed by a high-speed picture search unless special arrangements are made on the arrangement of data on the tape or the special reproduction function of the VTR. It is considered very difficult.
[0019]
[Problems to be solved by the invention]
As described above, in a conventional magnetic recording / reproducing apparatus, in a digital VTR in which image data encoded at a high compression rate is recorded, a high-speed picture search for searching an image is performed by a compression method or a signal processing circuit of a reproduction system. There is an inconvenience that it becomes a heavy burden on the public. Further, in the case of parallel recording by a digital VTR, there is a disadvantage that it is extremely difficult to display a discriminable image by a high-speed picture search.
[0020]
The present invention has been made in view of the above point, and in a digital VTR that records compressed image data, an image is searched without displaying an image by a high-speed picture search, and a tape is quickly moved to a necessary tape position. An object of the present invention is to provide a magnetic recording / reproducing apparatus which can easily obtain a reproduced image by transmitting the same.
[0021]
[Means for Solving the Problems]
[0027]
Also, as shown in FIGS. 1 to 8, the magnetic recording / reproducing apparatus of the present invention converts data supplied from a data supply source into a predetermined tape format, records the data on a tape by the recording / reproducing means 5, and converts the data into a tape format. In a magnetic recording / reproducing apparatus for retrieving data recorded on a tape by the recording / reproducing means 5 based on the recording / reproducing means 5 and searching for an image recorded on the tape, at the time of reproduction, the data recorded in the header area 24 provided at the head of the tape is Display means 170 for displaying image data as search data and tape position information 177, and designation means 189 for designating a desired tape reproduction position based on the image data displayed on the display means 170, When the position information 177 of the tape on the display means 170 indicates the vicinity of the desired reproduction position, the image data as the search data is doubled. Play, is obtained so as to display on the display unit 170 as a moving image.
[0028]
Further, as shown in FIGS. 1 to 8, the magnetic recording / reproducing apparatus according to the present invention has a search function for storing image data 82, 84 as search data and tape position information 86 corresponding to the image data 82, 84 in the above description. The data storage means 9 is provided. When the tape is mounted, the tape is rewound to the beginning of the tape, and the recording / reproducing means 5 reproduces the header area 24 provided at the beginning of the tape. The search data is stored in the search data storage means 9, and the search data stored in the search data storage means 9 is displayed on the display means 170.
[0029]
As shown in FIGS. 1 to 8, the magnetic recording / reproducing apparatus of the present invention fast-forwards the tape when the tape position information 177 of the display means 170 indicates a position distant from the desired reproduction position. The image data as search data is sequentially displayed on the display means 170.
[0030]
[Action]
[0036]
Further, according to the present invention, at the time of reproduction, display means 170 for displaying image data as search data recorded in header area 24 provided at the head of the tape and position information 177 of the tape, and display means And a designation unit 189 for designating a desired tape reproduction position based on the image data displayed on the display 170. When the position information 177 of the tape on the display unit 170 indicates that the vicinity of the desired reproduction position is displayed, it is used as search data. Is reproduced at double speed and displayed as a moving image on the display means 170. Therefore, the image data can be easily restored with a clear moving image, and a high-speed picture search is not required. The necessary images can be searched for and reproduced.
[0037]
Further, according to the present invention, in the above, there is provided a search data storage means 9 for storing image data as search data and tape position information corresponding to the image data. Then, the header area 24 provided at the head of the tape is reproduced by the recording / reproducing means 5, the search data recorded in the header area 24 is stored in the search data storage means, and the data is stored in the search data storage means. Since the search data is displayed on the display means 170, an image search is performed based on the image data included in the search data displayed on the display means 170, so that the partially reproduced signal is obtained. The desired image can be located at the beginning without performing the high-speed picture search described above.
[0038]
Further, according to the present invention, when the tape position information 177 of the display means 170 indicates a position distant from the desired reproduction position, the tape is fast-forwarded and image data as search data is displayed on the display means 170. Are sequentially displayed, so that the image is searched for based on the image data included in the search data displayed on the display means 170 so as to approach the desired reproduction position, and the partial reproduction is performed. The desired image can be located at the beginning without performing a high-speed picture search based on the signal.
[0039]
【Example】
FIG. 1 is a block diagram showing a schematic configuration of an embodiment of a magnetic recording / reproducing apparatus according to the present invention. In this example, the magnetic recording / reproducing apparatus of the present invention includes a search data extractor 3 having a function of extracting tape position information and image information necessary for image search and storing the extracted information in an internal semiconductor memory 9. It is characterized by the point provided.
[0040]
As shown in FIG. 1, during recording, the analog input image signal supplied to the A / D converter 1 is converted into digital image data. The image data is supplied to the recording encoder 2, where the image is compressed as necessary, and then necessary signal processing such as addition of an error correction code and shuffling is performed. The recording data processed by the recording encoder 2 is supplied to a recording / reproducing unit 5 via a switch 4 and recorded on a tape (not shown).
[0041]
At the time of reproduction, reproduction data reproduced from a recorded tape (not shown) of the recording / reproduction unit 5 is supplied to a reproduction decoder 6. The reproduction decoder 6 performs necessary signal processing such as deshuffling and error correction, and expands the compressed image as necessary. The image data that has been subjected to the signal processing by the reproduction decoder 6 is supplied to a D / A converter 7 and converted into an analog output image signal. The analog output image signal is displayed on the display 8. In FIG. 1, electrical and mechanical control of the entire magnetic recording / reproducing apparatus is performed by a system controller (not shown).
[0042]
Up to this point, it corresponds to the conventional magnetic recording / reproducing apparatus shown in FIG. 9 except that the recording encoder 2 is provided with the search data extractor 3 and the semiconductor memory 9 incorporated therein in parallel with the switch. 4 in that the recording encoder 2 is switched. The search data extractor 3 has a function of extracting tape position information and image information necessary for image search and storing the extracted information in the internal semiconductor memory 9.
[0043]
FIG. 2 is a diagram showing a tape format of an embodiment of the magnetic recording / reproducing apparatus according to the present invention. A header area 24 is reserved in the tape head portion 20 in advance. The header area 24 is so small as to be negligible in view of the recording / reproducing time of the entire tape, and the time required for formatting is desirably, for example, within one minute.
[0044]
It is also effective to preliminarily perform only formatting. In the first tape identification data area 21 of the header area 24, the serial number of the VTR that has formatted this tape and the number indicating the number of the tape that has been formatted are recorded. In the next search data recording areas 22 and 23, tape position information and image information extracted during recording of the image are recorded. In the last image recording area 27, image data similar to a normal VTR is recorded. The header area 24 includes a recorded search data recording area 22 and an unrecorded search data recording area 23. The image recording area 27 includes a recorded image recording area 25 and an unrecorded image recording area 26 up to the tape rear end portion 28.
[0045]
FIG. 3 is a block diagram showing a detailed configuration of a recording system of one embodiment of the magnetic recording / reproducing apparatus according to the present invention. In FIG. 3, an analog or digital video signal supplied to an analog / digital video signal input section 30 is converted into parallel video data. The parallel video data is supplied to a DCT blocking circuit 31, and after a predetermined DCT blocking, is supplied to an intra-field shuffling circuit 32. The intra-field shuffling circuit 32 rearranges the parallel video data within the field. This is because the compression process is completed within one field without using the redundancy in the time axis direction in order to enable editing and variable-speed reproduction in field units.
[0046]
The parallel video data rearranged by the intra-field shuffling circuit 32 is supplied to the bit rate reduction unit 71. The parallel video data supplied to the bit rate reduction unit 71 is converted from a time axis component to a frequency component by the DCT converter 33, quantized by the quantizer 34, and subjected to variable length encoding by the variable length encoder 35. . The bit rate reduction unit 71 employs DCT, and in combination with a variable length code, efficiently reduces the bit rate and controls the quantization to reduce the data amount to half. The quantization control is to perform fixed-length processing such that the data amount becomes constant after variable-length coding in quantization.
[0047]
The video data supplied from the bit rate reduction unit 71 is added with an outer error correction code by an outer code ECC encoder 36 for a video signal, and track interleaved.
[0048]
The search data extracted by the search data extractor 3 from the parallel video data rearranged by the intra-field shuffling circuit 32 is stored in the built-in semiconductor memory 9 and required by the bit rate reduction circuit 38. The data is compressed to a sufficient data rate, the outer error correction code is added by the outer code ECC encoder 39 for the video signal, and track interleaving is performed.
[0049]
The analog or digital audio signal supplied to the analog / digital audio signal input unit 40 is converted into serial audio data. After the serial audio data is shuffled by the shuffling circuit 41, an outer error correction code is added by the audio signal outer code ECC encoder 42, and is field shuffled by the intra-field shuffling circuit 43.
[0050]
Here, the video data and the audio data are supplied to a video / audio / search data multiplex circuit 44 and multiplexed. The multiplexed data is added with ID data by an ID adding circuit 45, scrambled by a scrambling circuit 46, supplied to an inner code ECC encoder 47, subjected to inner ECC encoding, and supplied to a synchronous signal adding circuit 48. Then, sync data is added.
[0051]
The recording data to which the sync data has been added is supplied to the partial response class 4 encoder 49 and channel-coded. Here, channel coding by the partial response class 4 is performed. As a result, low-frequency and high-frequency components are suppressed, and more energy is used in the midrange. The recording data thus channel-coded is recorded on the tape 51 by the recording head 50.
[0052]
FIG. 4 is a block diagram showing a detailed configuration of a reproducing system of one embodiment of the magnetic recording / reproducing apparatus according to the present invention. In the reproduction system, the processing is performed in the reverse flow to the recording system. In FIG. 4, recorded data recorded on a tape 51 is reproduced by a reproducing head, and the reproduced data is supplied to a Vidabi decoder 53 for decoding. By using the Viterbi decoding method, the C / N and, consequently, the error rate are improved. The Vidabi decoding method is a method of determining whether the value of the current data is 0 or 1 based on past data. There is a possibility that the 0/1 determination is erroneous as compared with a method of simply determining 0/1. Is significantly reduced.
[0053]
The reproduction data decoded by the Viterbi decoder 53 is supplied to a synchronization signal detection circuit 54, where sync data is detected. The reproduced data from which the sync data has been detected is supplied to the inner code error decoder 55, and the inner error is corrected based on the inner ECC coding. The reproduced data subjected to the inner ECC decoding is supplied to the ID detection circuit 56, where the ID data is detected. The reproduction data from which the ID data has been detected is descrambled by a descramble circuit 57, supplied to a video / audio / data demultiplex circuit 58, and demultiplexed.
[0054]
The demultiplexed video data is supplied to a video signal outer code error decoder 64, and outer error correction is performed based on outer ECC coding. The video data with the outer error corrected is supplied to the variable length code decoder 65 of the inverse bit rate reduction unit 72, is subjected to variable length code decoding, is supplied to the inverse quantizer 66, is inversely quantized, and is inversely DCT transformed. The signal is supplied to the converter 67 and subjected to inverse DCT. The reproduction data that has been processed by the inverse bit rate reduction unit 72 is supplied to the intra-field deshuffling circuit 68 and is subjected to field deshuffling.
[0055]
The reproduction data subjected to the field deshuffling is supplied to an error concealment circuit 69 so that an error which cannot be corrected by error correction is not output. Tape and head errors can usually be corrected by an error decoder, but if the error is not corrected due to deterioration of the condition, effective concealment is required. In this case, it is desirable that there be no tripping in the worst case such as a head clog. The error-concealed reproduction data is supplied to the analog / digital video signal output unit 70 and displayed on the display 8.
[0056]
The demultiplexed audio data is supplied to an intra-field deshuffling circuit 59, and is subjected to field deshuffling. The audio data subjected to the field deshuffling is supplied to the outer code error decoder 60 for the audio signal, and the outer error is corrected based on the outer ECC coding. The reproduced audio data in which the outer error has been corrected is supplied to the deshuffling circuit 61 and deshuffled. The deshuffled playback audio data is supplied to an error concealment circuit 62, and errors in the audio data that cannot be corrected by the inner and outer parts are error concealed. The error-concealed reproduced audio data is supplied to an analog / digital audio signal output unit 63.
[0057]
FIG. 5 is a diagram showing a helical track of one embodiment of the magnetic recording / reproducing apparatus according to the present invention. Here, video data and audio data for one field are recorded by six tracks. In FIG. 5, tracks 73 to 78 are recorded diagonally. The tracks 73 to 78 are provided with a video sector 79, an audio sector 80, and a video sector 81. In the video sector 79, search image data (video) 82 is recorded, and in the video sector 81, search image data (video) 84 is recorded. In the unnecessary audio sector 80, for example, a tape ID 85, a tape position 86, frame information 87, a program name 88 and the like are recorded. These search image data (video) 82 and 84, a tape ID 85, a tape position 86, frame information 87, a search data 83 including a program name 88 and the like are recorded.
[0058]
The embodiment of the magnetic recording / reproducing apparatus according to the present invention operates as follows with such a configuration. FIG. 6 is a flowchart showing the operation of one embodiment of the magnetic recording / reproducing apparatus according to the present invention. After starting, when the tape is mounted, the tape is rewound to the beginning of the tape in step S1, and the header area is reproduced. In step S2, it is determined whether the header area has been formatted. If the header area has not been formatted in step S2, the header area is formatted in step S3. If the header area has been formatted in step S2, a recording or reproducing command is received, and in step S4, it is determined whether the command is a recording command or a reproducing command.
[0059]
That is, when the tape is mounted on the digital VTR as the magnetic recording / reproducing apparatus of this example, first, the tape is rewound to the head by a driving unit (not shown), and the recording / reproducing unit 5 reproduces the header area. If the header area 24 has not been formatted, the header area at the head of the tape is secured and formatting is performed to record the tape identification data. During playback or formatting of the header area, a recording or playback command is input.
[0060]
If it is a recording command in step S4, the image data is fast-forwarded to the image recordable area and stopped in step S5. Upon receiving the recording command, image recording is started in step S6, and search data is extracted. Upon receiving the end command, the image recording ends in step S7. In step S8, rewind to the header area. In step S9, the search data is written, and the process ends.
[0061]
That is, when a recording command is input, the image is automatically fast-forwarded to the head of the area where image recording is possible and stopped. If it is a tape to be recorded for the first time, it will go to the head of the image recording area, and if it is a recorded tape, it will go to the head of an unrecorded area of the image recording area.
[0062]
After that, recording is performed by connecting the input signal. While recording is being performed, image data is also input to the search data extractor 3 to extract and accumulate image data necessary for image search, and to execute tape position information sent from a system controller (not shown). To accumulate.
[0063]
When the continuous recording is completed, a command to return to the header area at the head of the tape is issued from a system controller (not shown), and the data stored in the search data extractor 3 is automatically written to the point where it is written. .
[0064]
If the recorded image has a program name or the like, the program name may be input during recording, and may be written to the header area after the recording is completed. Also, in the case where recording is frequently performed next to continuous recording, it is inefficient to return to the header area and write the search data every time. Alternatively, the setting may be made changeable so that the header area is recorded in anticipation of tape replacement or the like.
[0065]
Further, in the actual operation of the digital VTR, it is necessary to switch the input source, rewind or exchange the source tape, and so on. Even when recording is continued, there is a sufficient time to return to the header area and write the search data. is there.
[0066]
If it is a reproduction command in step S4, search data is displayed in step S10. In response to the designation of the tape position, the search image is displayed by fast-forwarding in step S11. In step S12, double speed reproduction is performed. Upon receiving the reproduction command, normal reproduction is performed in step S13, and the process ends upon receiving the end command.
[0067]
That is, when a reproduction command is input, a representative screen, position data, and the like are displayed on the display 8. The user searches for an image based on the image data of the search data displayed on the display 8, roughly knows the tape position where the desired image is located, and specifies the tape position.
[0068]
As a result, the tape of the digital VTR is fast-forwarded by drive means (not shown). During fast forward, the digital VTR only feeds the tape quickly, and does not display an image based on the reproduced data. Instead, the image data of the stored search data is sequentially displayed.
[0069]
Then, when it comes near the designated tape position, double-speed playback is performed at a specified tape feed speed, which is 2 to 4 times faster than normal playback, and a moving image as clear as possible is displayed. This double-speed playback may be performed at a fixed tape feed speed at which data can be easily restored, and it is necessary to display a moving image at an arbitrary or any number of tape feed speeds as in a normal VTR. There is no. When the required image is obtained by the fixed-speed high-speed reproduction, a reproduction command is input again to switch to normal reproduction.
[0070]
In this way, it is possible to quickly and easily find and reproduce a necessary image without requiring a high-speed picture search.
[0071]
If it is difficult to realize double-speed playback due to the compression method or the like, this function may be omitted and normal playback may be started when the tape position is reached. .
[0072]
Further, by providing a function of automatically sending a tape in advance to a position near a tape position estimated from a search operation before the tape position is designated, the time required for fast-forwarding to the designated tape position can be reduced. It may be.
[0073]
Although the description so far has been only for a general type of VTR that records one input signal, the present invention can be applied to a case of a type of VTR that records several types of input signals in parallel. The configuration and operation of the example magnetic recording / reproducing apparatus can be basically applied in the same manner.
[0074]
However, in the above-described search data extractor 3, it is necessary to perform a process of extracting and storing search data for each input signal, arranging the search data, and recording the data in the header area 24. At the time of reproduction, a function of displaying image data of search data for each input signal is required.
[0075]
Although all of the description so far has been limited to digital VTRs for business use, analog VTRs of the conventional format are considered to be the mainstream for home use VTRs for some time. The basic part of the present invention, the automatic recording by extracting the search data during recording and rewinding the tape after the end of continuous recording, can be applied to a home analog VTR. This is extremely easy.
[0076]
Further, in a stationary VTR used for long-time recording, the embodiment of the present invention can be applied as it is. In a VTR such as a video movie used for fragmented recording, search data is extracted and stored during recording, and the data is rewound and held without recording as long as the storage capacity of the internal memory allows. When the memory becomes full, a warning may be issued and then writing may be performed. If writing of search data is not performed even when the internal memory is full, old search data may be thinned out and new search data may be written.
[0077]
Next, a method of extracting search data and an image search method will be described. A method of extracting search data, a method of displaying the data, and a method of searching for an image will be described below, but it goes without saying that the description given here is merely an example.
[0078]
As a method of extracting search data during recording, the search data extractor 3 samples images at a time interval of about 30 seconds, compresses the images, and compresses the images together with additional data such as tape position information. 9 is stored.
[0079]
In this case, it is examined how much time interval should be taken to replace the high-speed picture search when the tape is fast-forwarded. Assuming that the tape speed when fast-forwarding the tape can be up to 120 times the speed at the time of playback, if one image is captured and displayed every 30 seconds, when fast-forwarding at 120 times, Four images can be sequentially displayed in one second. If images are switched during fast forward at such a frequency, high-speed picture search can be substituted.
[0080]
Next, consider how much data this will be. In the NTSC system, 30 images are switched per second, so if this is compared with the total number of images, it is only 1/1800, and assuming that a tape with a recording and reproduction time of 120 minutes is used. This corresponds to an image for 4 seconds. Since it is not a continuous image, it is difficult to compress using correlation in the time axis direction.However, since it is not intended for high-quality reproduction, it is used as a substitute for high-speed picture search, additional data such as tape position information is used. There is no problem even if the data is compressed to a data rate of about 10 Mbps including the above. This is a total of 40 Mbits in 4 seconds, and therefore data can be accumulated if the semiconductor memory has 5 Mbytes or more.
[0081]
FIG. 7 is a diagram showing a display screen of search data of the magnetic recording and reproducing apparatus according to one embodiment of the present invention. In FIG. 7, the display 170 of the search data is divided into a search window 171, a representative screen window 172, and an operation window 173. The search window 171 displays four types of information: time axis information (TIME SCALE) 174, video index (VIDEO INDEX) 175, display position (VIEW) 176, and tape position (TAPE) 177.
[0082]
The video index (VIDEO INDEX) 175 is for grasping the outline of the image recorded on the entire tape, and the image captured for search by the search data extractor 3 shown in FIG. In this example, one slit is selected per image and displayed along the time axis. This is a so-called video browser (VIDEO) independently developed by the applicant of the present invention.
BROWSER). A video browser (VIDEO BROWSER) is an image in which sample images of images recorded on a tape are arranged in a strip shape in the time axis direction.
[0083]
In the representative screen window 172, some images of the portion designated by the arrow indicating the display position 176 in the search window 171 are reduced and displayed. This is to supplement image information that is difficult to understand with the video index 175. After selecting one of the small screens, the display range of the search window 171 and the operation of the magnetic recording / reproducing device are operated.
[0084]
The operation window 173 is a section where switches for displaying search data and operating the magnetic recording / reproducing apparatus are arranged. The display method of the representative screen window 172 is selected by "MODE", and "TIME" is displayed at substantially equal intervals in time, and a portion where a scene change has occurred is selected and displayed at appropriate intervals. “SCENE” and the like are prepared.
[0085]
The display range of the search window 171 is specified by “SCALE”, “FULL” for displaying the entire display, “ZOOM UP” for enlarging the display around the selected representative screen, and the currently displayed range. A command such as “ZOOM DOWN” for performing a reduced display for displaying a twice as large range as is provided.
[0086]
When these commands are selected, the display range of the search window 171 changes and the display of the representative screen window 172 also changes. The operation of the VTR as the recording / reproducing unit 5 of the magnetic recording / reproducing apparatus shown in FIG. 1 is performed in the "VTR" part, where the tape is fast-forwarded to the tape position where the selected screen is recorded. Alternatively, a search command “SEARCH” for rewinding, “PLAY” for reproducing from the current tape position, “REC” for recording, and “STOP” for stopping tape feeding are provided.
[0087]
Since the search is basically performed by selecting the representative screen window 172, the command of "FF" for fast-forwarding the tape and the command of "REW" for rewinding the tape prepared in a general VTR are not necessarily required. Further, a function of changing the speed during the search and a function of performing the slow reproduction may be added as needed.
[0088]
Image search is performed in the following procedure. First, by looking at the search window 171 and the representative screen window 172, an outline of the image recorded on the entire tape is grasped. Next, by changing the display range, the vicinity of the screen to be searched for is grasped in more detail. When a representative screen close to the desired image is obtained, the user selects this and inputs a search command. FIG. 8 is a diagram showing a display screen during a search of one embodiment of the magnetic recording / reproducing apparatus according to the present invention. In FIG. 8, during the search, the tape position 177 of the search window 171 moves and the screen of the representative screen window 172 becomes one, and the image data included in the search data is synchronized with the actual tape position 177. , Display as large as possible.
[0089]
Then, when the tape reaches the designated tape position, the VTR automatically starts reproduction. If a part you want to watch appears on the way, you can switch to playback by inputting a playback command.
[0090]
In the case of the VTR, it is not necessary to feed the tape until a search command is input. However, when the user starts to limit the display range, the tape is quickly forwarded to a nearby position in advance and the function waits. May be provided. As a result, the time required to fast-forward the tape to the designated position can be reduced.
[0091]
Also, as shown in FIG. 8, a desired position (SELECT) 189 indicating information of a time position at which the tape is to be fed is displayed, and when any of the representative screens is selected, this display is also displayed at the time position. You may make it move. In this case, referring to only the time axis information 174 and the video index 175, by directly moving the display of the desired position (SELECT) 189 and then inputting a search command, it is possible to quickly search the representative screen without having to search the representative screen. May be realized.
[0092]
In this case, when the desired position (SELECT) 189 coincides with the tape position (TAPE) 177, it is desirable that the display of the desired position (SELECT) 189 be turned off. Then, when the tape position (TAPE) 177 is selected, or when a certain representative screen is selected, this is separated into two and the display of the desired position (SELECT) 189 is generated.
[0093]
Also, as a search method when a number of types of programs are recorded on one tape, in the first display, the representative screen window 172 is omitted, and a search window 171 for only programs is displayed. If the title of each program has already been input, it is displayed simultaneously. Then, after grasping the outline of each program, when a search window 171 displaying a program to be searched is selected, the screen shifts to a screen as shown in FIG. 7 so that an actual search can be performed. May be.
[0094]
By doing so, the most efficient compression method and recording format can be adopted by removing the constraint of the high-speed picture search function accompanied by image display, and the amount of tape used in a digital VTR can be significantly reduced. It becomes possible to reduce.
[0095]
Further, only by reproducing the header portion in which the search data is recorded, necessary and sufficient image information of the image recorded on one tape is obtained, so that the image retrieval becomes easy. Further, the header area 24 may be provided at the rear end of the tape.
[0096]
Further, since the search data and the image data always exist on one tape, only the tape can be handled independently, and the management becomes easy.
[0097]
In addition, by storing only the header area portion in the database of the external storage device, even if the number of tapes becomes large, it becomes easy to centrally manage and use the tapes.
[0098]
According to the above example, the tape format is such that the header area 24 is provided in advance at the beginning of the tape, and at least the tape ID 85 as the tape identification data for identifying the tape and the tape ID 85 are extracted from the image recorded on the tape. The recorded image data 82 and 84 and the search data 83 including the tape position information 86 corresponding to the image data 82 and 84 are recorded, so that the image data 82 and 84 and the tape are stored in the header area 24 based on the tape format. The position information 86 can be recorded and completed as the search data 83.
[0099]
Further, according to the above example, in the above description, the tape ID 85 as the tape identification data records the serial number of the magnetic recording / reproducing apparatus and the number indicating the number of the tape. Thus, the magnetic recording / reproducing device used for the tape recording can be specified.
[0100]
Further, according to the above example, in the above description, the image data is recorded in the part after the header area 24 as the image recording area 27. Therefore, based on the tape format, the image recording area is searched by the search data in the header area 24. 27 image data can be searched.
[0101]
Further, according to the above example, at the time of recording, the search data extractor 3 as image data extraction means for extracting image data to be recorded on the tape at predetermined time intervals, and the image data 82 and 84 as search data 83. And a semiconductor memory 9 as search data storage means for storing tape data 86 corresponding to the image data 82 and 84, and the image data 82 and 84 are extracted by the search data extractor 3 as image data extraction means. Since the image data 82 and 84 as the search data 83 and the tape position information 86 corresponding to the image data 82 and 84 are stored by the semiconductor memory 9 as the search data storage means, the image used for the search at the time of recording is stored. By accumulating the data 82 and 84 and the tape position information 86, the search data 83 can be easily created.
[0102]
Further, according to the above example, when the tape is mounted, the tape is rewound to the beginning of the tape, and the recording / reproducing unit 5 as recording / reproducing means reproduces the header area 24 provided at the beginning of the tape. Since the search data 83 recorded in the header area 24 is stored in the search data storage means, the search data 83 of the recorded part of the header area 24 provided in advance is further compared with the search data 83 of the unrecorded part. 83 can be stored and added.
[0103]
In the above description, when the tape is mounted, when the header area 24 is not formatted by the tape format, the tape is rewound to the beginning of the tape to secure the header area 24, Formatting of a tape for recording identification data may be performed.
[0104]
In the above description, if the tape has been formatted or the formatting has been completed, the head of the unrecorded area 26 of the image recording area 27 is moved to the head of the image recording area 27 if the tape is to be recorded for the first time. Then, the tape may be automatically sent and then stopped.
[0105]
Further, according to the above example, in the above, when the continuous recording is completed, the tape is rewound to the beginning of the tape, and the search data stored in the semiconductor memory 9 as the search data storage means is recorded in the header area 24. Therefore, the recording of the header area 24 can be efficiently performed when the operation of the magnetic recording / reproducing apparatus is not performed without returning to the header area 24 and writing the search data 83 each time recording is performed.
[0106]
In the above description, when a number of types of signals are input and recorded in parallel, search data is extracted and stored for each input signal, and these are arranged and recorded in the header area 24. You may do so.
[0107]
Further, according to the above example, at the time of reproduction, the display 170 as display means for displaying the image data as the search data recorded in the header area 24 provided at the head of the tape and the position information 177 of the tape. Designation means 189 for designating a desired tape playback position based on image data displayed on the display 170 as a display means, and the tape position information 177 of the display 170 as a display means is provided near the desired playback position. Is displayed, the image data as the search data is reproduced at double speed and displayed as a moving image on the display 170 as a display means, so that the image data can be easily restored with a clear moving image. Quick and easy picture search without the need for high-speed picture search. Kill.
[0108]
Further, in the above example, when the tape comes to the designated desired reproduction position, normal reproduction may be performed.
[0109]
In the above description, when several types of signals are input and recorded in parallel, the search data may be arranged and displayed, and the image search may be performed independently. .
[0110]
Further, according to the above example, in the above, the semiconductor memory 9 is provided as search data storage means for storing image data as search data and tape position information corresponding to the image data, and when a tape is mounted, The tape is rewound to the beginning of the tape, the header area 24 provided at the beginning of the tape is reproduced by the recording / reproducing unit 5 as recording / reproducing means, and the search data recorded in the header area 24 is stored in the retrieval data storage means. Since the search data stored in the semiconductor memory 9 as the search data storage means is displayed on the display 170 as the display means, the image data included in the search data displayed on the display 170 as the display means is based on the search data. Searching for images in this way makes it possible to perform high-speed picture searches based on partially reproduced signals. No, it is possible to carry out the beginning of the seek image.
[0111]
According to the above example, in the above description, when the tape position information 177 on the display 170 as the display means indicates a position distant from the desired reproduction position, the tape is fast-forwarded, and the image data as search data is changed. Since the images are sequentially displayed on the display 170 as the display means, an image search is performed based on the image data included in the search data displayed on the display 170 as the display means so as to approach the desired reproduction position. This makes it possible to find a desired image without performing a high-speed picture search based on a partially reproduced signal.
[0112]
Also, in the above example, the time required for fast-forwarding to the specified tape position is provided by having a function for automatically sending the tape in advance to the vicinity of the tape position estimated from the search operation before the tape position is specified. May be shortened.
[0113]
【The invention's effect】
[0119]
Further, according to the present invention, at the time of reproduction, display means for displaying image data as search data recorded in a header area provided at the head portion of the tape and position information of the tape, and display means for displaying on the display means Means for designating a desired playback position of the tape based on the reproduced image data, and when the position information of the tape on the display means indicates the vicinity of the desired playback position, the image data as search data is played back at double speed. Since the moving image is displayed on the display means, the image data can be easily restored with a clear moving image, and the necessary image can be quickly and easily located without the need for a high-speed picture search. Can be played.
[0120]
Further, according to the present invention, in the above, there is provided search data storage means for storing image data as search data and tape position information corresponding to the image data, and when the tape is mounted, rewinds to the head of the tape. Then, the header area provided at the beginning of the tape is reproduced by the recording / reproducing means, the search data recorded in the header area is stored in the search data storage means, and the search data stored in the search data storage means is displayed. Means, the image is searched based on the image data included in the search data displayed on the display means, thereby performing a high-speed picture search based on the partially reproduced signal. Without this, it is possible to find the desired image.
[0121]
According to the invention, when the position information of the tape on the display means indicates a position distant from the desired reproduction position, the tape is fast-forwarded and the image data as search data is sequentially displayed on the display means. Therefore, based on the image data included in the search data displayed on the display means, an image search is performed so as to approach the desired playback position, and based on the partially reproduced signal, The desired image can be located at the beginning without performing the high-speed picture search described above.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an embodiment of a magnetic recording / reproducing apparatus according to the present invention.
FIG. 2 is a diagram showing a tape format of an embodiment of a magnetic recording / reproducing apparatus according to the present invention.
FIG. 3 is a block diagram showing a detailed configuration of a recording system of one embodiment of the magnetic recording / reproducing apparatus of the present invention.
FIG. 4 is a block diagram showing a detailed configuration of a reproducing system of an embodiment of the magnetic recording / reproducing apparatus of the present invention.
FIG. 5 is a diagram showing a helical track of one embodiment of the magnetic recording / reproducing apparatus of the present invention.
FIG. 6 is a flowchart showing the operation of one embodiment of the magnetic recording / reproducing apparatus of the present invention.
FIG. 7 is a diagram showing a display screen of search data in one embodiment of the magnetic recording / reproducing apparatus of the present invention.
FIG. 8 is a diagram showing a display screen during a search of one embodiment of the magnetic recording / reproducing apparatus of the present invention.
FIG. 9 is a block diagram showing a configuration of a conventional magnetic recording / reproducing apparatus.
FIG. 10 is a block diagram showing a configuration of an image recording apparatus using a conventional workstation.
[Explanation of symbols]
1 A / D converter
2 Record encoder
3 Search data extractor
4 switch
5 Recording and playback unit
6 playback decoder
7 D / A converter
8 Display
9 Semiconductor memory
20 Tape head
21 Tape identification data area
22 Search data recording area (recorded)
23 Search data recording area (unrecorded)
24 Header area
25 Image recording area (recorded)
26 Image recording area (unrecorded)
27 Image recording area
28 Tape rear end
82 Image data for search (video)
84 Image data for search (video)
83 search data
85 Tape ID
86 Tape position
87 Frame information
88 Program name
170 Display
177 Tape position
189 desired position

Claims (3)

The data supplied from the data supply source is converted into a predetermined tape format and recorded on the tape by the recording / reproducing means, and the data recorded on the tape is reproduced by the recording / reproducing means based on the tape format and the tape is reproduced. A magnetic recording / reproducing apparatus that searches for an image recorded in
During playback,
Display means for displaying image data as search data recorded in a header area provided at the beginning of the tape and position information of the tape,
Designating means for designating a desired playback position of the tape based on the image data displayed on the display means,
A magnetic recording / reproducing apparatus characterized in that when the position information of the tape on the display means displays near the desired reproduction position, the image data is reproduced at a double speed and displayed on the display means as a moving image. . The magnetic recording / reproducing apparatus according to claim 1 ,
Search data storage means for storing the image data as the search data and tape position information corresponding to the image data,
When the tape is mounted, the tape is rewound to the beginning, and the recording / reproducing means reproduces the header area provided at the beginning of the tape,
Storing the search data recorded in the header area in the search data storage means,
A magnetic recording / reproducing apparatus, wherein the search data stored in the search data storage means is displayed on the display means. The magnetic recording / reproducing apparatus according to claim 1 ,
When the position information of the tape on the display means indicates a position distant from the desired reproduction position, the tape is fast-forwarded, and the image data as the search data is sequentially displayed on the display means. A magnetic recording / reproducing apparatus characterized by the above-mentioned.

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