JPH01272385A - Digital static image recording system - Google Patents

Abstract

PURPOSE:To record high vision static image data by a DAT with a simple constitution by storing the 1st and 2nd digital data in an image memory and a sound memory and then outputting the stored contents through a data switching circuit. CONSTITUTION:The 1st and 2nd digital data supplied at the 1st transmission rate are respectively temporarily stored in the image memory 5 and the sound memory 6. When a header detecting circuit 7 detects a sound header from the 1st digital data read out from the image memory 5, a clock signal switching circuit switches the supply of a clock signal with frequency corresponding to the 2nd transmission rate from the image memory 5 to the sound memory 6 and the 2nd digital data are read out from the sound memory 6 at the 2nd transmission rate and supplied to a data switching circuit 8. The circuit 8 outputs the 3rd digital data obtained by time-dividedly multiplexing the static image data and the sound data.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a digital still image recording system, and more particularly to a digital still image recording system in which high-definition still image data can be recorded by a digital audio tape recorder (DAT).

Prior Art The present applicant previously filed Japanese Patent Application No. 1981-281615 (title of the invention [Digital Video Signal Recording/Reproducing Method and Reproducing Apparatus J)] and Japanese Patent Application No. 110136/1982 (title of the invention "Digital Video Signal Recording Method and Reproducing Apparatus J"). We proposed a method for recording high-definition television (high-definition) signals as digital still image data on a digital audio disk (DAD).

7(A) and (B) respectively show block diagrams of a recording device and a reproducing device for recording and reproducing the above-mentioned still image data in the DAD. In FIG. 7(A), the video signal obtained by the high-definition camera 35 is , Δ/D converter 36 converts the still image data into digital data, which is then recorded on a magnetic tape 37.The still image data recorded on the magnetic tape 37 is converted into a predetermined format and time-edited in an editing tube 38. Furthermore, a header signal in which necessary information regarding the data is recorded is added to create a master chip 139 for cutting.

The zero image data recorded on the master tape 39 is supplied to the encoder 40 together with the audio data recorded on another master tape 141, where the error data is processed according to a predetermined method (for example, the AHD (registered trademark) method). 5.73 M as 4-channel data (2 channels each for still image data and audio data) with correction code added
The data is recorded on the master disk 42a at a transmission rate of bps. Thereafter, a disk (AH0 disk) 4 on which still image data is recorded based on this master disk 42a
2b is produced.

In the reproducing apparatus shown in FIG. 7(B), a 4-channel digital signal is obtained from the disc 42b by the reproducing decoder 43, and error correction using a predetermined method is performed here. Of these, two channels of audio data are converted into analog signals by a D/A converter 46, and output from a speaker 48 via an amplifier 47. On the other hand, still image data for the other two channels is supplied to the high-definition processor 44, and after predetermined operations are performed, it is displayed on the display 45.
Regarding the playback system, refer to the Technical Report of the Television Society of Japan VR'88-3LIan, 198B) ``Digital Hi-Vision Disc System'' (Nobuaki Takahashi).

Problems to be Solved by the Invention On the other hand, in recent years, digital audio tape recorders (DATs) have been put into practical use that can easily record and reproduce high-quality digital audio data with high quality. Since this DAT is capable of recording digital signals at high density, it has attracted attention from the beginning of its development as a recording medium for digital data other than audio data, and is also used, for example, as a data streamer for backing up computer digital data. ing. However, so far it has not been put to practical use as a recording medium for digital image data.

Digital audio disks (DADs) can simultaneously record and play back not only digital audio but also high-definition still image data, and because they provide high-quality images, they are opening up a new field of image retrieval systems. However, although this DAD can be easily reproduced, recording is not as easy as with magnetic tape.
Another drawback was that re-recording was impossible. Therefore, there has been a desire for a means for recording high-vision digital still image data using DAT, which allows easy recording and reproduction of digital data and has a high recording density.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a digital still image recording method that can record high-definition digital still image data using DAT by adding only a few means to a digital audio disk device. purpose.

Means for Solving the Problems The system of the present invention provides a first method that includes still image data, an image header in which information regarding the still image data is recorded, and an audio header in which an identification number of audio data and a word length of the audio data are recorded. an image memory that temporarily stores digital data at a first transmission rate; an audio memory that temporarily stores second digital data consisting of audio data and an audio header at a first transmission rate; header detection means for detecting an audio header from first digital data read at a second transmission rate and generating a detection signal indicating the detection result; Switch li! ii @ When the clock signal switching means to be supplied to the memory or the audio memory and the header detection means detect the audio header, the audio data corresponding to the audio data of the second digital data read from the audio memory is converted into the audio header. When the recorded word length is output and reading of the audio data is completed, the output data is switched to output the first digital data read from the image memory, and the identification number of the audio header in the first digital data and the first digital data are output. data switching means for outputting the audio data and the image data as third digital data at a second transmission rate by time-division multiplexing such that the identification numbers of the audio headers in the second digital data match; It consists of an existing recording and reproducing device that records or reproduces digital data on a recording medium at a second transmission rate, and records or reproduces still image data and audio data supplied at the first transmission rate at the second transmission rate. The configuration is such that recording is performed using an existing recording and reproducing device that generates σ1.

It is also possible to use compressed data as the audio data, in which case the compression rate is recorded in the audio header.

Operation The first digital data and the second digital data supplied at the first transmission rate are temporarily stored in the image memory and the audio memory, respectively.

When the header detection means detects an audio header from the first digital data read from the image memory, the clock signal switching means switches the supply of the clock signal of the frequency corresponding to the second transmission rate from the image memory to the audio memory, Second digital data is read from the image memory at a second transmission rate and supplied to the data switching means.

The data switching means switches the data so that the audio data in the second digital data is output at a temporal position where the identification numbers of the audio data recorded in the audio headers in the first and second digital data match. When the word-length reading of audio data from the audio memory is completed, the data is switched to output still image data, and the still image data and audio data are output as third digital data that is time-division multiplexed.

Embodiment FIG. 1 shows a block diagram of an embodiment of the present invention, and FIG. 2 shows a block diagram of the entire recording/reproducing system including the apparatus shown in FIG.

As shown in FIG. 3(A), the videotape played by the VTRII in FIG. A 6-word image header 31a1, as shown in the same figure (B), a 12-word display command 32 that defines the display method of the m* data 31, and a compressed audio data 33 as shown in the same figure (C). A four-word audio header 33a containing information is recorded. For example, 1 in the same figure (C)
The compressed audio data 33 consisting of 80 words (the number of words varies depending on the compression rate) is not recorded on the video tape in the VTR 1, but is recorded on the video tape in the VTR 14 together with the audio header 33a, and the word length is Varies depending on rate changes, etc. Each word of these digital data is 16 bits.

The videotape played by the VTRs 11 and 14 is
For example, it can be manufactured in the same manner as the process of manufacturing a master tape for recording high-definition still image data and audio data on a digital audio recording device (DAD). That is, in the case of DAD, the audio header 33a relating to audio data is unnecessary and is not recorded on the video tape played by the VTR 11, but in the case of this embodiment, the image data 31 and display commands 32 are not recorded at the editing stage. An audio header 33a regarding the compressed audio data 33 is recorded at a predetermined position between (,
Regarding the recording method of high-definition still image data using DAD, see Japanese Patent Application No. 60-281615 ``Digital Video Signal Recording and Reproducing Method and Reproducing Apparatus'' or Technical Report VR' 88-3 (Jan, 1989) of the Television Society of Japan.
88) "Digital Hi-Vision Disc System"
It is explained in detail in. ).

In this example, an average of 60 4-word audio headers of 338
Transmitted every 1/2 second, this increases the image data transmission rate from 1.411M bps to 1.407M bps
This causes a slight delay in the time it takes for one image to be transmitted. However, this delay is such that, for example, what is transmitted in 15 seconds becomes 15.04 seconds, and even if the audio header 338 is recorded between the compressed audio data 31 and the display command 32 and transmitted, There is no practical problem.

As mentioned above, the sampling frequency of digital data reproduced by the VTRs 11 and 14 is the same as that of DAD, and for example, AHD (registered trademark f[), which is a type of OA[).
In this case, the sampling frequency is 44.1 kHz, and 32 bits (16 bits x 2 channels) of data are transmitted for each sample.

The image header 31a shown in FIG. 3(A) consists of 6 words, and this first word has all bits set to 1, which serves as a synchronization signal and indicates that a header signal will follow next. . The second word is a word for identifying the format of image data. Especially the MSB and the second
The method shown specifically in FIG. 4 is identified using two bits. Therefore, in the case of this embodiment, it is either folJ or "11J.In the case of I'o1J, there is a possibility that further display commands are recorded successively, but the information after the third bit is The address value of the memory brain in which the image data should be stored is written in the third and subsequent words.

FIG. 5 shows a specific configuration of the audio header 33a in FIG. 3(C). The first word is a synchronization code similar to the image header 31a, and all 16 bits are 1. The upper two bits of the second word are a system code, which is "11" to indicate that this header is an audio header 33a, as shown in FIG. Furthermore, the third. The fourth bit indicates compressed audio data when it is "00".

The fifth to eighth bits are an identification code of the compressed audio data 33, and identification numbers relating to the compression method, compression rate, sampling frequency, number of quantization bits, etc. are recorded. The image data 31 is a still image, and a relatively small number of images need to be transmitted per unit time. can. In particular, in the case where image data such as background video (BGV) is transmitted mainly to li-fi audio, it is preferable that the compression ratio of the audio data is low. On the other hand, explanatory audio added to image files for image searches and the like does not need to be of very high quality, so the compression ratio can be increased. In order to change the compression rate in this way, data regarding the compression rate is recorded in the identification code. The compression ratio of these audio data and the number of images to be transmitted per unit time are determined at the editing stage when creating the master tape.

The 8 bits after the 9th bit of the second word and the third word are called a packet number, and a series of numbers are assigned to each packet of compressed audio data 33 shown in FIG. 3(C).

In this packet number, the second word is on the LSB side, and the third word is on the LSB side.
The word is on the MSB side, and the lower 8 bits of the second word are assigned the same packet number every 256 packets. By assigning packet numbers in this way, even if the synchronization between the audio header 33a recorded together with the image data 31 and the audio header 338 recorded together with the compressed audio data 33 is disrupted to some extent,
By specifying a packet number, compressed audio data can be time-division multiplexed at a predetermined position of image data, as will be described later.

The first to fourth bits of the fourth word are reserved for future use, and the fifth and subsequent 12 bits specify the word length of compressed audio data up to 4096 words. By specifying the word length of the compressed audio data 33 in this way, the number of words of the compressed audio data 33 to be read from the compressed audio memory 6 (FIG. 1), which will be described later, is specified, and the compressed audio data of the specified number of words is When the data is read out, the clock signal from the clock signal switching circuit 9 is switched from the compressed audio memory to the image memory 5, and the operation shifts to reading image data, etc.

The recording system interface circuit 13 shown in FIG. 2 is the main part of the present invention, and its specific configuration is shown in FIG. 1 together with the compressed audio memory 6. In FIG. 1, from terminal 2 there are 44.
1 kHz or an integral multiple of this frequency (44.1 kl-(z if the signal supplied to terminal 1 is parallel data such as 32 bits, 44.1 kHz (32+α) in the case of serial bit data) ) Double FM wave number.i
A clock signal of 44.1 kHz, 48 kHz, etc. is also representative of frequencies that are integer multiples thereof) is supplied to the digital audio processor 12 (FIG. 2), Playback data (image data 31) from the VTRII is synchronized with this clock signal.
, image header 31a1, audio header 33a1, including display command 32) are supplied to terminal 1 and temporarily stored in image memory 5.

Similarly, a 44.1 kHz clock signal is supplied from terminal 4 to digital audio processor 15.
Playback data (including compressed audio data 33 and audio header 33a) from the VTR 14 in synchronization with the Ock signal
is supplied to the terminal 3 and temporarily stored in the compressed audio memory 6. The above 44□1kHz output from terminal 2.4
The clock signal is obtained by converting the frequency of a 48 kHz clock signal supplied from a digital audio tape recorder (DAT>16) in the clock generation circuit 10.

When a predetermined amount of data is input to the image memory 5, a 48kHz signal from the clock signal switching circuit 9 is output from the image memory 5.
The data is read out in synchronization with the clock signal and supplied to the hengoo detection height 7 and the data switching circuit 8. The header detector 7 detects the audio header 338 shown in FIG. 3 from the data read from the image memory 5, generates a detection signal indicating the detection result, and outputs a detection signal to the data switching circuit 8 and the clock signal switching circuit. Supply to 9.

When the ladder detector 7 detects the audio header 338, the clock signal switching circuit 9 switches the supply of the 48k)-1z clock signal from the image memory 5 to the compressed audio memory 6. After the word branch data of the compressed audio data written in the audio header 33a is read out from the compressed audio memory 6 and supplied to the data switching circuit, the clock signal switching circuit 9 switches the clock signal supply again to the image data. The data is switched to the memory 5 and read out from the image memory 5 and supplied to the header detector 7 and data switching circuit 8.

The data switching circuit 8 switches the data read out from the image memory 5 and the compressed audio memory 6 according to the detection signal from the header detector 7 in the same way as the output signal switching circuit, and the image data 31 read out from the image memory 5 and the display command 32 The compressed audio data 33 having the same packet number is inserted into a predetermined position between them (the position where the audio header 33a is stored), is time-division multiplexed, and is output at a sampling frequency of 48kl-1z.

The data output from the data switching circuit 8 is 48kHz.
It is supplied to DΔT16 in Figure 2 at a sampling frequency of Record on tape. As described above, image data, compressed audio data, and display commands are transferred to the DAD using the DAD image recording device.
Recorded by Tl 6.

The image data and compressed audio data reproduced by the DAT16 are supplied to the reproduction system interface circuit 18 as digital data with a sampling frequency of 4.8 kHz, 32 bits. The interface circuit 18 determines whether it is image data 31 or compressed audio data 33 based on the header signal added to the beginning of each data.
or display command 32.

The image data 31 is sampled at a sampling frequency of 44.1 kHz by the reproduction system interface circuit 18.

The data is converted into 32-bit data and sent to one high-definition processor. Therefore, as the high-definition processor 19, for example, the high-definition processor (high-definition decoder) for DAD proposed by the present applicant in Japanese Patent Application No. 110136/1988 can be used as is.

FIG. 6 shows a concrete block diagram of the reproduction system interface circuit 18 provided on the reproduction side. In the same figure, DA
From Tl 6, data is serially supplied bit by bit to the input circuit 20 along with a clock signal a of 32 times (or more) 48 kHz. This data is delayed by two words in the shift register 21, and is supplied to the header detection circuit 22-, where the type of data is identified.

A detection signal indicating the identification result is sent to the data selector 23, which switches the signals supplied from the shift register 21 so that the image data is input to the image buffer memory 24, and the compressed audio data is input to the audio buffer memory 25. .

Further, the clock signal a that has passed through the input circuit 27 is converted into a clock signal of an integral multiple (for example, 70 times) of 44.1 kHz in the frequency multiplier circuit 26, and is sent to the image buffer memory 2.
4 and the audio buffer memory 25. Based on this clock signal bt, image data is output from the image buffer memory 24, and compressed audio data is output from the audio buffer memory 25, respectively.

The image data reproduced and extracted in this way is CA
Since the signal format is exactly the same as that of D, a high-definition still image can be obtained from this image data via the high-definition processor 9.

On the other hand, the compressed audio data is applied to a well-known compressed audio decoder 20 and decompressed in a manner opposite to compression to obtain the original audio signal, which is output in synchronization with the high-definition still image signal. Ru.

As described above, compressed audio data is inserted between 1.411 Mbps high-definition still image data, and 1.53 Mbps
It becomes possible to record on DAT as 6M bps digital data.

A ladder is recorded to the same audio on the videotape played back by the VTRII and 14, and the same Jll in the audio memory is used to specify the position where the audio data should be inserted by the consecutive identification numbers indicating the audio data in the audio header.
] The memory size for error absorption can be reduced, and synchronization errors of relatively long video tapes can be absorbed.

Effects of the Invention As described above, according to the present invention, conventional methods such as digital
It is now possible to record high-definition still image data and audio data that were previously recorded on audio discs (CAD), for example, on digital audio tape recorders (DAT), and it is also a great help when building image recording and playback systems. As for the photographing equipment or editing equipment, which are already in practical use, those for digital audio discs can be used as they are, and in the different systems of digital audio disc and digital audio tape recorder, master tape It has features such as being able to share the same information.

[Brief explanation of the drawing]

1 and 2 are block diagrams of an embodiment of the present invention, FIG. 3 is a configuration diagram of digital data, FIG. 4 is a diagram showing the meaning of digital data signals, and FIG. 5 is a diagram showing the meaning of digital data signals. FIG. 6 is a block diagram of a reproduction system interface circuit, and FIG. 7 is a block diagram of an example of a conventional device. 5... Image memory, 6... Compressed audio memory, 7...
・Header detection circuit, 8...Data switching circuit, 9...
- Clock signal switching circuit, 10... Clock generation circuit, 13... Recording system interface, 16... Digital audio tape recorder (DAT), 18
... playback system interface, 19... high-definition processor, 20... compressed audio decoder, 31.
... (still) image data, 31a... image header,
32... Display command, 33... Compressed audio data,
33a...Audio header. Patent applicant: Victor Japan Co., Ltd. I・・ -E, No: 1. Junk ω 0 0 Figure 4 Figure 5 1 beat.

Claims (1)

[Scope of Claims] A first digital file including still image data, an image header in which information regarding the still image data is recorded, and an audio header in which an identification number of audio data and a word length of the audio data are recorded. an image memory that temporarily stores data at a first transmission rate; an audio memory that temporarily stores second digital data including the audio data and the audio header at the first transmission rate; and an audio memory that temporarily stores the audio data and the audio header at the first transmission rate. header detection means for detecting the audio header from the first digital data read from the memory at a second transmission rate and generating a detection signal indicating the detection result; when the header detection means detects the audio header; Outputs the audio data corresponding to the audio header of the second digital data read from the audio memory for the word length recorded in the audio header, and when the reading of the audio data is finished, outputs the audio data corresponding to the audio header. The output data is switched to output the first digital data read from the memory, and the identification number of the audio header in the first digital data and the identification number of the audio header in the second digital data are changed. data switching means for outputting the audio data and the image data as third digital data by time division multiplexing at the second transmission rate so as to match the audio data and the image data at the second transmission rate; an existing recording and reproducing device that records or reproduces data on a recording medium at a second transmission rate; A digital still image recording method characterized by recording using a recording and reproducing device.