JPS5975777A - Recording and reproducing system for video format signal - Google Patents

Abstract

PURPOSE:To expand a system application range and to obtain an optimum system particularly suited to an educational system by controlling to substitute a part corresponding to a sound-information inserted part by another picture obtained from a computer, etc., on a reproduction side. CONSTITUTION:A block part where the sound information is inserted is substitued with another video signal obtained from the computer, etc., by a video synthesize (or masking) circuit 15, or clamped to a constant level such as a pedestal level and a mean video level (APL) and outputted. An external sound signal is selected as an output voice signal when no sound information is outputted or when a switch 16 is operated forcibly. A part shown by a dotted line in a figure is necessary to provide this decoder with an LL (Language Laboratory) function, and a leaner's microphone input voice is digitized by an A/D converter 18 and written in a time-axis expansion memory 10. This memory 10 serves as a tape recorder.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording and reproducing method for a video format signal, and more particularly to a method for recording and reproducing image information and audio information as a video format signal on the same recording track of a recording medium.

When audio information corresponding to image information is recorded on the same trunk on a recording medium together with image information, the audio information is compressed in time and inserted into one part of the video format signal, and the image information is inserted into the remaining part. There is a way. In the conventional method, the insertion pattern of audio and image information on a video format in one recording medium is fixed and fixed, making it impossible to obtain various playback operations during playback. .

Therefore, an object of the present invention is to provide a video format signal recording and reproducing system that enables various reproducing operations when reproducing image information.

The video format signal recording/reproducing method according to the present invention divides a two-dimensional screen obtained by a signal equivalent to one field (l frame) of the video format signal into a plurality of blocks, inserts audio information into a predetermined block, and inserts image information into the remaining blocks. The audio information is inserted and recorded, and the audio information insertion block portion is replaced with other image information from a computer or the like during playback.

Audio information is recorded with time axis compression, and when playing back, this time axis compressed audio information is extracted using a memory or the like to expand the time axis so that it becomes real time. The signals reproduced in this way can be used for videos of reproduced images or trick plays (
Steal, slow.

Steps, etc.) Since the audio information is recorded as a program, the length of the audio information per field read, that is, the audio time in real time, can be arbitrarily set in units of blocks.

This will become clear in the explanation below, but on the playback screen that includes audio information, while playing the audio, the audio is played back sequentially at a time equal to the length of the audio information for each field (frame). This means that the speed at which the playback screen is sent when outputting data can be set arbitrarily. Furthermore, since audio information can be inserted into any part of the screen, it is convenient to select and insert a less important part of the reproduced image.

In particular, the playback side [
By controlling the image to be replaced with another image obtained from a computer or the like, the range of system applications can be expanded, making it especially suitable as an educational system.

Furthermore, if control information for controlling the operation of the playback device is inserted and recorded together with the audio information, and a decoder is provided to read the control information, the decoder can control various operations of the playback device. In other words, by pre-embedding software for controlling the operation of the playback device in the recording medium, it is possible to control various playback operations simply by using a decoder and without installing any special circuit in the playback device. It will be possible.

The present invention will be explained below using the drawings.

FIG. 1 is a diagram showing the principle of the present invention without further explanation,
1 field of video format signal during recording: (1
Frame) A two-dimensional screen obtained by the Osho signal is shown. The upper edge, lower edge, and both side edge portions are vertical and horizontal blanking portions, and the portion surrounded by one-dot chain lines is the portion that appears on the actual screen of the monitor television. Of the two-dimensional screen excluding the vertical and horizontal blanking portions, the first number H (H means a horizontal scanning period) following the vertical blanking portion at the upper edge is used as a control signal insertion block.

It is indicated by diagonal lines in the figure. The rest of the screen is
The blocks are divided into m blocks in the horizontal direction and n blocks in the vertical direction to form m×n blocks. The block location where the time-axis compressed audio information is inserted is specified by the control signal, and the audio information insertion position on the screen is determined.

On the other hand, it is of course equivalent to specifying the inserting position and thickness of one piece of image information to determine the inserting block of audio information.

FIG. 2 is a diagram showing an example of inserting audio information. Audio information is inserted into the diagonally shaded block at the bottom right, and image information is inserted into the central area surrounded by the audio information insertion block. This means that A part of the audio information insertion block appears in the actual monitor screen surrounded by a dashed line, and this part is clamped to a certain level on the playback side or replaced with other image information from the outside. so that

Figure 3 shows the video format signal waveform during recording.
Although shown based on the C format, other formats such as the PAL format are also possible. Figure (5) shows the waveform before audio information is inserted.
Figure 2) shows a waveform with audio information inserted. A and b are test signals such as color pars, C is control information, and d is audio information, respectively.

In the figure, one screen planking (V-BLK) (
Although neither control information nor audio information is inserted in this example, it goes without saying that they may be inserted. Among the control information, at least those related to the audio information insertion position and the image processing method must be inserted at a predetermined portion at a position preceding the corresponding image. In some cases, audio information is recorded over several frames. In this case, it is sufficient to insert control information in a predetermined part of the first frame, but there is no problem in inserting it in other frames as well. is playing.

FIG. 4 is a block diagram of an encoder for obtaining a video format signal according to the recording method of the present invention. Analog audio signals are processed using ADM (Adaptive Delta
Modulation ) and ADPCM (Adapt
The signal is digitized in an analog-to-digital (A/D) converter l using a modulation method with a high compression effect, such as differential differential PCM. This digital signal is input to the error correction encoding circuit 2, where it is rearranged on the time axis, that is, interleaved, and then redundant bits are added so that an error correction code is completed for each block. The purpose of interleaving is to disperse errors in the digital signal on the time axis when signal dropouts occur due to scratches, dust, etc. on the video disk, which is the recording medium. The signal thus subjected to error correction encoding processing is written to the time axis compression memory 3 at the sampling frequency f1. The reading from this memory 3 is performed at a frequency f2 higher than the frequency f1.
0 Control signals, which are control information, include those that are extremely important to the system and require error detection and correction, and those that are less important and require error detection and correction. It can be classified as unnecessary. The former control signal includes a block number indicating the audio information insertion block, the aforementioned sampling frequency designation, audio information channel number designation (monaural, stereo, etc.), VDP (video disc player) playback operation designation, There are designations for continuous and discontinuous reproduction of audio information, group numbers for dividing audio information insertion blocks into groups, and these important control signals are input to the error correction encoding circuit 4.

This control signal is also encoded using a block-based error correction coding system, like the audio information, but unlike the audio information, it is preferable that it be a powerful correction code. This is because control information is extremely important to system operation.

On the other hand, flags indicating the presence or absence of cell audio information in individual fields (frames) are less important control messages and Philips codes (stop codes).When this code is played, VDP automatically Signals such as still playback) are directly input to the switching circuit 5, and are processed by the switching circuit 5 together with the output of the time axis compression memory 3, the output of the error correction encoding circuit 4, and the image signal (including the synchronization signal). It will be selected and output.

The selection operation of the switching circuit 5 is controlled by a timing signal generation circuit 6, and the writing and reading of the memory 3 are also controlled by the timing signal generation circuit 6. In the timing signal generation circuit 6, an internal oscillator is synchronized with the synchronization signal of the input image signal, and various timing signals are generated in accordance with external control signals and the like. From the output of the switching circuit 5, a video format signal is obtained in which time-axis compressed audio information is inserted into the desired block and image information is inserted into the remaining blocks.

FIG. 5 is a block diagram of a decoder for reproducing a video disc on which the video format signal obtained in this way is recorded. The Q7 audio information and control information separated from the reproduced signal in the signal separation circuit 7 are error corrected by error correction circuits 8 and 9, respectively. After that, the audio information is transferred to the time axis expansion memo 'J 1 (
1 is written to 1. The readout is performed using a low-speed clock equal to the sampling frequency, and the time axis is expanded to become real-time audio data. Thereafter, the signal is demodulated into the original analog signal by the D/A converter 11. Note that error correction is performed using the memory 10.
It may also be configured to perform time axis expansion at the time of reading from the data.

Both the error-corrected control signal and the control signal that does not require error correction are input to the system control circuit 12. This circuit 12 controls the entire decoder system and further controls the VDP using control No. 1 separated from the reproduction signal and an external control signal.

cormorant. Since the reading of audio information from the memory 10 is not necessarily performed immediately after writing, it is necessary to store the control signal 4e necessary for the reading, and therefore the memory 13 for control signals is It is set up for that purpose. The timing signal generation circuit 14 has an internal oscillator synchronized with the synchronization signal separated in the signal separation circuit 7, and generates various timing signals according to the control signal and supplies them to each block in the decoder. do.

The block portion into which audio information has been inserted is processed by video synthesis (or
is replaced with another video signal obtained from a computer or the like in the masking circuit 15, or output after being clamped to a constant level such as a pedestal level or an average video level (APL).

The external audio signal is selected as the output audio signal when audio information is not being output or when the switch 16 is forcibly switched. This external audio signal is, for example, an FM-processed two-channel audio signal obtained within a VDP (not shown). Note that the system control circuit 12 outputs the V included in the regenerated control signal.
A control signal for the reproduction operation of the DP is generated and outputted to the VDP (not shown) via the player controller 17.

The part indicated by the dotted line in the figure is the so-called LL in this decoder.
(Language Laboratory) This is necessary when providing a function, and the learner's microphone input voice is digitized by the A/D converter 18 and written into the time axis expansion memory 10. This memo IJ 10 will serve as a tape recorder, and if the output of this memory 1o is read out at the reading frequency f1, the voice information of the model pronunciation and the own microphone input will be recorded. It becomes possible to compare the pronunciation with the original pronunciation.

It is necessary to switch the sampling frequency f1 for writing to the memory 3 and reading from the memory 3 in FIG. 4.5 depending on the content of the audio information in order to efficiently utilize the information transmission medium. Now, according to the sampling theorem, the sampling frequency must be at least twice the signal frequency band, but if the audio information is music, it has a wide frequency band, and therefore a high sampling frequency is required. On the other hand, if it is a human voice, a low sampling frequency is sufficient. Therefore, in order to switch and use the sampling frequency according to the audio information, it is preferable to include the designation of this sampling frequency in the control information. Further, since music information is stereo (two channels) and human voice is generally monaural (one channel), it is also useful to include the designation of the number of channels in the control information. Therefore, the designation of the sampling frequency and the number of audio channels are included in the control information as described above.0 Figure 6 shows an example of the processing of the reproduced image. is a reproduced image with audio information inserted (indicated by diagonal lines),
This reproduced image is sent to the video synthesis (or masking) circuit 15 in the decoder shown in FIG.

(8) or (C). Figure (B
), the audio information insertion block is replaced by an image from an external source such as a computer, and in FIG. 3(C), for example, the pedestal level is replaced. Figure 1
Method 3) is useful when used as an educational device,
This allows interaction between the user and the computer. For example, a certain problem appears in an image and the corresponding audio information is output, and then the image, that is, the problem remains as it is, and the answer is output from the computer as text or an image, and the
]). It is also possible to display characters that instruct the next operation.

A control signal (or flag) indicating the insertion of audio information in every frame (field) where audio information is inserted.
Image processing can be performed easily and reliably by inserting the cursor and referring to this control signal. That is,
By detecting this 'control signal, it becomes possible to input necessary images from the outside into the audio information insertion section independently of the state of the video signal and system operation.

FIG. 7 is a diagram showing the relationship between the audio information insertion mode and the reproduced image, and the cases of A, 2 and O are shown in (5) and (B). First, referring to the fourth time, when the audio information of each frame (field) is continuously played back while transmitting the playback image, the audio information (shown as 8wS data, 5t
ill p'1ture with 5o-und) is an abbreviation for each frame (can also be a field)
It is inserted and recorded in each block at the upper and lower edges of. To reproduce such a signal, the SWS data in the first frame is written to the first area of the time axis expansion memory (memo IJ and 10 in Figure 5, and the same shall apply hereinafter), and this writing is performed at the start of reproduction of the second frame. Read data while expanding the time axis. At this time, all SWS data in the second frame is simultaneously written to the second area of the time axis expansion memory, and following the completion of reading the 8wS data in the first frame, this written data is read out while expanding the time axis, and Playback of 3 frames is started and all of this SWS data is written in the first area. This operation is then repeated in sequence, and the audio information is successively output on the real time axis and the corresponding image is reproduced. In this case, the mode of the reproduced image is that only the first frame is a moving image, and from the second frame onwards, images are sent in a time equal to the length of 8wS data of each frame, so normal playback (moving image) is performed according to the length of the data.

Slow motion, step motion (so-called frame advance), etc. are possible. In this example, the two areas of the time axis expansion memory 10 are read and written to each other, and the two areas may overlap slightly, so the memory capacity is less than 2 frames of 8wS data. It can be done.

If you refer to FIG.
This is an example in which WS data is inserted and only image information is recorded in each of the remaining frames. To reproduce this signal, while performing normal reproduction on VDP', the 8wS data of these six preceding frames are sequentially written to the time axis expansion memory.
Audio information is read out from the memory in real time from the start of reproduction of the seventh frame image. In this case, the mode of the reproduced image can be a moving image, slow motion, step, still, etc. In this example, since it is necessary to store all 8wS data within six frames, a memory capacity larger than that in the four-time example is required.

On the other hand, in the four-time example, if we were to play stills, the audio time per frame is short, so it would be necessary to send many identical screens in steps, which would reduce the number of still images that can be recorded. be.

However, in the example of FIG. fBl, there is an advantage that the number of still images that can be recorded increases by cB, although the memory capacity increases.

Incidentally, even if all 8wS data is stored in the memory as shown in Figure (Bl), data may be inserted only at the upper and lower edges of the image, as shown four times.

In this way, various VDP operations are possible depending on the relationship between the insertion mode of 8wS data and the image. Since the control of writing and reading of the memory is different in these various operations, that is, the seventh operation and the operation (B), it is necessary to appropriately switch and instruct these based on the control information. Also, in VDP, different actions such as slow, step, steal, etc. may be required depending on the image content, so
All of these operation switching instructions are performed by signals included in the control information.

Figure 8 is a diagram showing another relationship between the audio information insertion mode and the reproduced video signal, and is an example of the seventh position method.The first frame (field) is transmitted during normal playback, and the next frame Then, depending on how many frames the 8wS data per frame corresponds to, VDP' is controlled to transmit frames for each frame number. In the example shown in the figure, frames are advanced every four frames. First, SwS data α is written to the memory, and from the start of reproduction of the next frame, this data α is expanded on the time axis and read out, and during that time, SwS data b is written to the memory. When the reading of data α is completed, data b is subsequently read out with time axis expansion in the same way, and the next data C is written into the memory portion where data cL was stored during this time. Thus, the data αl b I
' l d l . . . are written once each and read out continuously, making it possible to reproduce continuous sound.

Since each data of a-cZ corresponds to the length of an integer frame, if the capacity of the time axis expansion memory 10 is two frames of data, each data α in each frame in the figure
The insertion positions of data α to d can be inserted arbitrarily, but the reading start and end positions of each data α to d can be kept constant regardless of the data insertion positions to produce continuous audio. The images during this time are still played back every 4 frames, resulting in a frame-by-frame playback image. Here, it is impossible to distinguish between normal playback and frame-by-frame playback with only the playback signal from the vDP. In the case of Figure 8, if the decoder determines that normal playback has continued, the S
The wS data h, C, or df readability will also be written to the memory. In order to prevent such a situation, it is necessary to determine whether the contents of the 8wS data are the same in the previous frame and the subsequent frame, and control information is also used for this determination. In the case of multiple channels, multiplexing is performed within one block so that the number of 8wS data for each channel is equivalent to an integer frame (field). If this is expressed as a formula, ND=Nc-NF-fl/fF. ND is the number of 8wS sampling data in one block, Nc is the number of audio channels, NF is the corresponding frame (number of fields) of 8wS data in one block, f
l is the sampling frequency and fF is the frame (field) frequency.

FIG. 9 is a diagram showing still another relationship between the audio information insertion mode and the reproduced image, and shows an audio information insertion block? Furthermore, the information is grouped and a group number is assigned to each group, so that a series of focused audio information differs for each group. - For example, S inserted into all blocks of the first and second frames (fields) as shown
The WS data group is set to group number 0, and Japanese audio is inserted into this group. Set the SWS data group inserted in all the third and fourth frames as group number 1, and insert English audio into this group δ
Similarly, the SWS data groups of the fifth and sixth frames are set to number 2 and are made into French audio. It is assumed that only image information is inserted into subsequent frames. Then, these group numbers are included in one piece of control information, and this group number is designated by a command signal from an external switch, computer, etc., and selective reading is performed.

For example, the figure shows a state in which the French audio of group number 3 is specified and read. This will be written to the 7th frame, expanded on the time axis, and read out from the 7th frame. Of course, it is also possible to perform data filling for all groups and perform selective operation only during reading, but this is not preferable if the memory capacity is limited.

In addition to selecting this language, this example can also be used to ask a question and select and output different responses or comments depending on the user's response, making it ideal for educational purposes. . This is particularly effective when this SWS/stem is incorporated into an interactive video system combined with a computer.

FIG. 10 is a diagram explaining the relationship between the insertion mode of audio information and control information and the reproduced audio output mode, and is an application example in which the group number of the SWS data shown in FIG. 9 is included in the control information. In Figures (A)' and (B), 8.
-8i is the SWS data group number, C is a control signal indicating that selective writing to memory is possible, C
2 is a control signal for performing continuous audio output operation, C
Reference numerals 5 and 5 designate control signals for starting reading from the memory.

In the example shown in FIG. 7 (A), voice information of group number S1 among the SWS data is selectively stored in the memory.
), it operates as continuous audio output. VI) P is in normal playback mode at first, and 2
By performing still playback on the group numbers that appear after the first time, and performing normal playback when the read content is switched, continuous audio output without skipping frame-by-frame is possible. 1
If the readout time exactly corresponds to the length of i + l frames, continuous sound may be output for the image feed moving image in group S, instead of still playback.

FIG. 10(B) shows the same operation as in FIG. 9, in which the audio information of the group number S is selectively written into the memory, the reading is started after the writing is completed, and the next step is performed after the reading is completed. The data of number 7<S is stored in the memory.

In addition, the symbol (↑) in Figure (B) means that player control is not necessary when outputting audio to a moving image.

In both the examples in Figures (A) and (B), the start of reading is S. ~
No matter which one of S is selected, reading ends at the end of S, but reading may be started immediately after writing is completed, and in this case, control signal C8 is not required. Note that the insertion block position of the SWS data in the video format signal is an arbitrary position specified by the control signal.

Selection of loading or reading of SWS data is possible by control information as described above, but it is also possible by external control. In other words, it is possible to provide a flexible and expandable system that can be controlled by a computer. For example, depending on the group number, SWS
If the time axis expansion memory area in which data is written is differentiated, the group number of the input SWS data is changed according to predetermined conditions and written to a different storage area, and the previously written SW
It is possible to prevent S data from being deleted. By using control signals such as those shown above, various advanced functions become possible.

The above-mentioned system is a versatile and multifunctional type, but as a result, it has a complicated configuration and costs are high, so in order to put it into practical use, it is necessary to have somewhat limited functions, simplify the configuration, and lower costs. There are cases where For example, if the number of audio channels and sampling frequency are fixed,
The control signals used for this are no longer required, and the SWS
If the timing for reading data from the time axis expansion memory is determined to start immediately after the data is read out, a control signal for starting reading becomes unnecessary. Furthermore, if the player's actions are also limited, it will be simplified. For example, in an optical video disc player, if it is set such that the continuous playback is performed at the filter node and the normal playback is started when the reading of data from the 5WS4 memory is completed, there is no need to add these control signals.

As an example, human voice is used as audio information and this is used as ADPCM.
If expressed as a digital signal, if an image is to be sent in bits per second, that is, as a moving image, a transmission rate of about 9666 bits per field is sufficient. This is recorded on two horizontal short straight lines that do not appear on the motor television screen at or near the vertical blanking. That is, the first
As shown in Figure 1, 333-bit data may be superimposed on the IH. In Figure (A), a is a test signal, b is audio information, and Figure (B) is an enlarged view thereof. If the audio channel output is 2 channels, it is sufficient to record in 4H. If music is also transmitted as audio information, the transmission rate must be increased, so the number of H's to superimpose the data is increased.0 Also, if an attack bit is also added as an error correction code, the number of H's is increased. Increase the number or I
The number of bits in H may be increased. In this way, audio information can be added to a moving image without substantially reducing images.

An example in which the capacity of the time axis expansion memory can be significantly reduced in the case of continuous audio output will be described with reference to FIG. ``It is assumed that the amount of audio information inserted into one frame (field) is constant and corresponds to the image information of multiple frames (fields), and the audio information insertion position within the frame is constant. Now, the writing speed to memory is faster than the reading speed, so if you start reading immediately after starting writing as shown in 4 in the figure, the information that has been written will always be read.α , b, c, d... is equivalent to 3 frames, so albI
The start time of each readout of the information "l'Z..." is always constant within each frame. Therefore, the end position of each readout is used as the write line of the last data of the next audio information, and at the switching point of the audio information If read at the same timing, it is possible to output continuous audio and at the same time, the memory capacity is a + b r ' l
The amount of information read out until the end of writing of each audio information is subtracted from the amount of one audio information of d..., which results in an extremely small capacity. In reality, it is necessary to provide a margin for distortion, distortion, etc. of the reproduced signal, and in order to facilitate control, the capacity may be set to be the same as each piece of audio information in one frame. The number of frames to which each piece of audio information corresponds is arbitrary as long as it is an integer value, and one frame constitutes a moving image.

As shown above, according to the present invention, professionalized audio information can be inserted at any location on the screen generated by the video format signal, so that various functions can be added to the playback operation during playback. be able to. In particular, since an image from a computer or the like is inserted at the location where audio information is inserted, there is an advantage that it can be applied as an educational device.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the basic principle of the present invention, Fig. 2 is a diagram showing a playback screen pattern of an embodiment of the invention, and Fig. 3 is a diagram illustrating a video format signal waveform of an embodiment of the invention. , FIG. 4 is a block diagram of an encoder for implementing the recording method of the present invention, FIG. 5 is a block diagram of a decoder for implementing the reproducing method of the present invention, and FIG. 6 is a block diagram of an embodiment of the present invention. FIGS. 7 to 9 are diagrams illustrating reproduction operations according to each embodiment of the present invention;
FIG. 10 is a diagram explaining the relationship between SWS data, control information, and reproduction operation, FIG. 11 is a signal waveform diagram showing another embodiment of the present invention, and FIG. 12 is a reproduction of another embodiment of the present invention. It is a figure which shows operation|movement. Explanation of symbols of main parts 1.18 ...A/D converter

Claims (2)

[Claims] (1) A two-dimensional screen obtained by a video formant signal is divided into multiple blocks, audio information is inserted into a predetermined block, image information is inserted into the remaining blocks, and recorded on a recording medium, and upon playback, the audio information is A recording/playback method that replaces the inserted block portion with other image information. (2) A control signal for identifying the insertion of the audio information is inserted into each field (frame) having a block in which the audio information is inserted and recorded. recording and playback method.