JPH11195268A - Sound recording method specifying copied source recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To specify a source recording medium copied from a duplicate recording medium by disabling an illegal copying trader to take a copy except a source display digital signal. SOLUTION: In this sound recording method which specifies the copied source recording medium, a sound image digital signal is inputted to and recorded on the duplicate recording medium 2 from the source recording medium 1 stored with the sound image digital signal that becomes a sound image analog signal when D/A-converted. At this time, only when the sound image digital signal meets specific conditions, the source display digital signal specifying the source recording medium 1 is inputted to the duplicate recording medium 2 together with the sound image digital signal and both the sound image digital signal and presence display digital signal are recorded on the duplicate recording medium 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to, for example, a CD,
The present invention relates to a recording method for specifying a source from a recording medium recording an audio / video digital signal, such as a laser disk or a recording tape.

[0002] In the present specification, the term "audio / video digital signal" means that a digital signal is converted into an analog signal.
It means a signal that becomes a music signal or an image signal.

[0003]

2. Description of the Related Art An illegally copied music CD, music tape, laser disk, or the like, commonly called a "pirate board", is commercially available. A pirated CD or laser disk cannot identify the source recording medium from the recorded digital signal. This is because the signal for specifying the source, which has been recorded on the recording medium serving as the source, is not recorded on an illegally copied pirated CD or the like.

[0004]

SUMMARY OF THE INVENTION A pirated C that copies all digital signals recorded on a source recording medium
D and the like can specify the source recording medium from the digital signal recorded on the pirate board. However, since the illegal copy trader cuts the source indication digital signal for identifying the source and copies only the audio-video signal, the source indication digital signal cannot be reproduced from the pirated CD, and becomes the source. The recording medium, that is, the source recording medium cannot be specified.

SUMMARY OF THE INVENTION The present invention has been developed to solve such a drawback, and an important object of the present invention is to provide a source copy digital signal for an illegal copy trader to specify a source recording medium. It is another object of the present invention to provide a recording method in which only the audio / video signal cannot be copied, except that the source indication digital signal can be reproduced from the duplicate recording medium and the copied source recording medium can be specified.

[0006]

According to the recording method for specifying a copied source recording medium according to the present invention, when D / A conversion is performed,
An audio / video signal of a digital signal is input to a duplicate recording medium 2 from a source recording medium 1 stored as a digital signal which is an audio / video signal of an analog signal, and an audio / video signal of a digital signal is recorded on the duplicate recording medium 2 This is an improved recording method.

According to the recording method of the first aspect of the present invention, when an audio / video digital signal is input from the source recording medium 1 to the duplicate recording medium 2, the audio / video digital signal satisfies a specific condition. A source indication digital signal for specifying the recording medium 1 is input to the duplicate recording medium 2 together with the audio / video digital signal, and both the audio / video digital signal and the source indication digital signal are recorded on the duplicate recording medium 2.

According to the recording method of the present invention, the digital signal of the duplicate recording medium 2 storing both the audio-video digital signal and the source indication digital signal is compared with the digital signal of the source recording medium 1. , A difference signal between the source recording medium 1 and the duplicate recording medium 2 is obtained. A source indication digital signal is detected from the difference signal, and the source recording medium 1 is specified.

According to a third aspect of the present invention, there is provided a recording method for specifying a copied source recording medium.
In the state where the analog signal is converted into the analog signal by the A / A conversion, only when the level of the analog signal is higher than the set level and is higher than the set rate of change, the source display digital signal and the audio / visual digital signal are copied to the copy recording medium. Record in 2.

According to a fourth aspect of the present invention, there is provided a recording method for specifying a copied source recording medium, comprising the steps of:
It is characterized in that the set level of the audio / video digital signal input to the duplicate recording medium 2 is changed by calculating from the average value of the analog signal level obtained by D / A conversion of the audio / video digital signal.

According to a fifth aspect of the present invention, there is provided a recording method for specifying a copied source recording medium, wherein a digital audio signal is input from the source recording medium to the duplicate recording medium.
At a random timing, a source indication digital signal specifying the source recording medium 1 is input to the duplicate recording medium 2 together with the audio / video digital signal, and both the audio / video digital signal and the source indication digital signal are recorded on the duplicate recording medium 2.

According to a sixth aspect of the present invention, there is provided a recording method for identifying a copied source recording medium, wherein a source indication digital signal recorded on a duplicate recording medium 2 is detected by the same method as the second aspect. I do.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below illustrate a recording method for embodying the technical idea of the present invention, and the present invention does not specify the recording method as follows.

Further, in this specification, in order to make it easy to understand the claims, the numbers corresponding to the members shown in the embodiments will be referred to as “claims” and “ In the column of “means”. However, the members described in the claims are not limited to the members of the embodiments.

The recording method for specifying a copied source recording medium according to the present invention, as shown in FIG.
Is input to the duplicate recording medium 2 and the audio / video digital signal of the source recording medium 1 is recorded on the duplicate recording medium 2.

When an audio / video digital signal is input from the source recording medium 1 to the duplicate recording medium 2, a source display digital for specifying the source recording medium 1 only when the audio / video digital signal satisfies a specific condition. The signal is input to the duplicate recording medium 2 together with the audio / video digital signal, and both the audio / video digital signal and the source indication digital signal are recorded on the duplicate recording medium 2.

The audio / video digital signal recorded on the source recording medium 1 is a digital signal that becomes an audio signal such as music or vocal music or a signal that becomes an image when D / A converted. The audio signal is a signal having a frequency lower than the audible frequency, for example, 20 kHz or less. Compared with audio signals, image signals have considerably higher frequencies, ranging from several MHz to several tens of MHz.

The sampling frequency of the audio / video digital signal is, for example, 44.1 MHz or 90 MHz.
z. The frequency of the audio signal is extremely lower than the sampling frequency of the audio / video digital signal. Therefore, the origin display digital signal is recorded on the duplicate recording medium 2 together with the audio signal, and the audio signal of the duplicate recording medium 2 can be reproduced with almost no distortion. This is because the origin display digital signal is recorded at an extremely high frequency as compared with the audio signal, so that the audio signal can be reproduced by completely removing the source display digital signal with a filter that passes only the audio signal.

The origin display digital signal can be recorded on the duplicate recording medium 2 together with the image signal. Duplicate recording medium 2 recording a source display digital signal together with an image signal
, The difference in the image due to the origin display digital signal is hardly recognized. This is because the image reproduced from the duplicate recording medium 2 differs from the image reproduced from the source recording medium 1 only in an extremely narrow spot.

The source indication digital signal recorded together with the audio / video digital signal on the duplicate recording medium 2 is, for example, numbers or characters for specifying a source, as shown in FIG. The source display digital signal of FIG.
It is a number consisting of 190. The numbers 0 to 9 can be specified by a 4-bit digital signal.

The apparatus shown in FIG. 1 includes a reproducing apparatus 3 for reproducing a source recording medium 1, a mixer 4 for adding a source indication digital signal to an audio / video digital signal output from the reproducing apparatus 3 and outputting the digital signal, and a mixer. 4 includes an input device 5 for outputting a source indication digital signal, and a recording device 6 for recording the audio / video digital signal and the source indication digital signal output from the mixer 4 on the duplicate recording medium 2.

The reproducing device 3 reproduces an audio / video digital signal recorded on the source recording medium 1 and inputs the audio / video digital signal to the mixer 4 in the form of a digital signal.

The input device 5 has a keyboard for inputting numbers and characters specifying the source recording medium 1. The numbers and characters input from the keyboard are converted into digital signals and output to the mixer 4.

The mixer 4 has a memory 7 for storing a source display digital signal input from the input device 5, and stores the source display digital signal in the memory 7. The memory 7 is a RAM. Further, the mixer 4 calculates an audio / video digital signal output from the playback device 3 and determines a timing for adding the source display digital signal to the audio / video digital signal, and is controlled by the arithmetic circuit 8. And an addition circuit 9 for adding the source display digital signal to the audio / video digital signal and outputting the digital signal.

The arithmetic circuit 8 converts the audio / video digital signal
Only when the analog signal level is higher than the set level and larger than the set change rate in the state where the analog signal is converted into an analog signal, the mixing signal is output to the adding circuit 9.

The arithmetic circuit can output a mixing signal at random timing. This arithmetic circuit is
For example, a mixing signal is output at random times several times a minute. This arithmetic circuit includes, for example, a random number generation circuit, and is designed to output a mixing signal when a specific random number is output.

FIG. 2 shows a state in which the source indication digital signal is added to the audio / video digital signal. However, for the sake of simplicity, FIG.
A state in which a source display digital signal is added to the A-converted signal is shown. The amplitude of the quantized signal obtained by D / A conversion of the audio / video digital signal is changed in synchronization with a clock having a sampling frequency. When the level of the quantized signal is higher than the set level and higher than the set change rate, the origin display digital signal is added to the audio-visual digital signal.

In FIG. 2, first, the gradient of the quantized signal, that is, the rate of change of the audio / video digital signal is α, β.
The source display digital signal is added to the audio-visual digital signal at two places where the change rate is larger than the set change rate and the quantized signal level is higher than the set level. The source indication digital signal adds the source indication digital signal to the audio / video digital signal at the next clock when it is determined that the quantized signal is larger than the set level and larger than the set change rate. The arithmetic circuit 8 detects the level of the quantized signal and whether the rate of change is greater than the set value. When the level and the rate of change of the quantized signal are larger than the set values, the arithmetic circuit 8 adds the mixed signal to the adder 9
Output to The adding circuit 9 adds the origination display digital signal to the audio / video digital signal in synchronization with the next clock with the input mixing signal.

The source display digital signal, the numeral "4" in FIG. 2, is repeated a plurality of times, added to the audio / video digital signal, and output to the recording device 6. For example, the source display digital signal is repeatedly added 5 to 20 times to the audio / video digital signal and output. Duplicate recording medium 2
This is for accurately detecting the source display digital signal by comparing the source display medium 1 with the source recording medium 1.

The source display digital signal repeatedly outputs the same number a predetermined number of times to the recording device 6, and then repeatedly outputs the next number. For example, as shown in FIG.
.., 222 ..., 888 ..., 111 ..., 9
When the audio-video digital signal satisfies the set conditions in the order of 99... 000, the audio-video digital signal is added to the audio-video digital signal and output to the recording device 6.

The level of the quantized signal from which the arithmetic circuit 8 outputs the mixing signal is not specified to a constant value. This is to output the source display digital signal at predetermined time intervals even when the level of the quantized signal is continuously low. For example, when a small sound is continuously recorded on the source recording medium 1, the level of the quantized signal decreases for a certain period of time and does not increase. If the arithmetic circuit 8 is designed to output the mixing signal only when the level of the quantized signal is higher than the specified level that does not fluctuate, in this state, the mixing signal is not output for a long time. For this reason, when small sounds continue,
The source display digital signal cannot be added to the audio / video digital signal and output.

In order to solve this drawback, the level of the output of the mixing signal from the arithmetic circuit 8 is adjusted by the level of the analog signal converted from the audio / video digital signal, in other words, by the average value of the signal levels of the quantized signals. I do. The arithmetic circuit 8 for realizing this adjusts the level at which the mixing signal is output low when the signal level of the quantized signal is continuously low, and when the signal level of the quantized signal is continuously high, Adjust the output level of the mixing signal higher.

The recording device 6 records both the audio-visual digital signal output from the mixing signal and the origination display digital signal on the duplicate recording medium 2. In this state, in the duplicate recording medium 2 on which the audio-video digital signal is recorded, a source indication digital signal is recorded in addition to the audio-video digital signal.

The duplicate recording medium 2 and the source recording medium 1 are compared by the apparatus shown in FIG. 4, and a digital signal indicating the origin is detected. The comparison device 10 synchronously compares the digital signal of the duplicate recording medium 2 that stores both the audio-video digital signal and the source indication digital signal with the audio-video digital signal of the source recording medium 1. When a difference signal between digital signals of the source recording medium 1 and the duplicate recording medium 2 is detected,
An origin display digital signal is detected from the detected difference signal.

The comparison device 10 compares the digital signals output from the duplicate recording medium 2 and the digital signal output from the source recording medium 1 synchronously at a sampling frequency. From the difference between the two digital signals to be compared, a source indication digital signal is obtained. When the digital signal on the duplicate recording medium 2 is compared with the digital signal on the source recording medium 1, a source indication digital signal indicated by a chain line in FIG. 2 is obtained. The source display digital signal is 444
, 333, 222, 888,
.., 000, 000... From this signal, a source indication digital signal consisting of “4328190” can be detected.

FIG. 5 shows that the reproducing apparatus 3 outputs three types of audio / video digital signals including a clock signal, an L / R timer signal, and a source data signal, and adds a source indication digital signal to this output. FIG. 2 is a block diagram of a device that outputs the data to a recording device 6.

This device includes an input buffer 11 to which a clock signal, an L / R timer signal, and a source data signal are input, and a clock signal from the input buffer 11 which is input to a
A clock timer circuit 12 for outputting to U17 and an output of input buffer 11 for calculating a mixing signal
17, a delay circuit 15 that delays and outputs a source data signal of the input buffer 11, and a source data signal output from the delay circuit 15 that is output from the CPU 17. And an output buffer 18 for outputting an output signal of the mixing circuit 16, an L / R timer signal and a clock signal. The CPU 17 includes an input keyboard 19 for inputting a source display digital signal, and a memory 20 storing software for processing by the CPU 17.

The average value detection circuit 13 is provided with the input buffer 1
An average value of the source data signal output from 1 is detected, and a mixing signal is output when the average value of the signal is larger than a set value. The average value detection circuit 13 detects a peak of the source data signal input from the input buffer 11, and detects an average value of the source data signal from the peak value.

The change rate detecting circuit 14 is provided with the input buffer 1
The change rate of the source data signal output from 1 is detected, and when the change rate of the signal is greater than a set value, a mixing signal is output. The change rate detection circuit 14 also detects a peak of the source data signal input from the input buffer 11, and detects a change rate of the source data signal from the peak value.

The delay circuit 15 delays the source data signal and inputs it to the mixing circuit 16. Delay circuit 15
The time for delaying the source data signal is set to the time until the average value detection circuit 13, the change rate detection circuit 14, and the CPU 17 calculate the source data signal and output it to the mixing circuit 16. In other words, the source data signal is transmitted from the delay circuit 15 to the mixing circuit 16 at the timing of the change rate detection circuit 14 and the CPU 1.
7 and the timing of input to the mixing circuit 16 is adjusted to the same time.

The mixing circuit 16 adds the source indication digital signal output from the CPU 17 to the source data signal input from the delay circuit 15 and outputs the signal. CPU
The signal output from 17 is output from the output buffer 18 to the recording device 6. The output buffer 18 outputs an L / R timer signal and a clock signal in addition to the source data signal input from the mixing circuit 16. L
Although not shown, the / R timer signal and the clock signal are delayed by the delay circuit 15 and input to the output buffer 18 at the same timing as the source data signal. The L / R timer signal and the clock signal can be input to the CPU 17 from the input buffer 18 and can be input to the output buffer 18 in synchronization with the CPU 17.

The CPU 17 uses the flowchart of FIG.
A source display digital signal is output from the source data signal. This flowchart shows a state in which a three-digit source display digital signal consisting of 432 is output.

[Step N1] In this step, the CP
U17 determines whether a mixing signal has been input from both the average value detection circuit 13 and the change rate detection circuit 14. This step is looped until a mixing signal is input from both circuits.

[Step N2] When a mixing signal is input from both the average value detection circuit 13 and the change rate detection circuit 14, whether or not the first digit source display digital signal "4" has been output a predetermined number of times is determined. Is determined.

[Step N3] If the first digit source indication digital signal "4" has not been output a predetermined number of times, the first digit source indication digital signal "4" is output.
Thereafter, the process jumps to the step N1.

[Step N4] When the first digit source indication digital signal “4” is output a predetermined number of times,
It is determined whether or not the digitized source display digital signal “3” has been output a predetermined number of times.

[Step N5] If the second digit source indication digital signal "3" has not been output a predetermined number of times, the second digit source indication digital signal "3" is output.
Thereafter, the process jumps to the step N1.

[Step N6] When the second digit source indication digital signal "3" is output a predetermined number of times, 3
It is determined whether or not the digitized source display digital signal “2” has been output a predetermined number of times.

[Step N7] If the third digit source indication digital signal "2" has not been output a predetermined number of times, the third digit source indication digital signal "2" is output.
Thereafter, the process jumps to the step N1.

[Step N8] The third digit source display digital signal "2" is output a predetermined number of times, and the process ends.

Thereafter, the CPU 17 executes the above N1 to N7
Is repeated to output a source display digital signal to the mixing circuit 16 as an audio / video digital signal.

[0052]

According to the recording method of the present invention for specifying a copied source recording medium, since the audio-visual digital signal and the source indication digital signal are recorded on the duplicate recording medium, the duplicate recording medium is compared with the source recording medium. By doing so, it is possible to detect the source indication digital signal recorded on the duplicate recording medium. For this reason, the recording method of the present invention has an advantage that the source recording medium can be easily and reliably specified from a pirated CD or the like obtained by copying the duplicate recording medium. In particular, the recording method of the present invention prevents an illegal copying company from copying only an audio-visual digital signal except for a source indication digital signal for identifying a source recording medium, and ensures that an illegally copied duplication recording medium cannot be copied. Has a feature that a source recording medium can be specified.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of an apparatus used for a recording method according to the present invention.

FIG. 2 is a graph showing a state in which a source indication digital signal is added to an audio / video digital signal recorded by the recording method of the present invention.

FIG. 3 is a graph showing a state in which a source display digital signal is recorded.

FIG. 4 is a block diagram showing an apparatus for comparing a duplicate recording medium with a source recording medium.

FIG. 5 is a block diagram showing an example of an apparatus used for the recording method of the present invention.

FIG. 6 is a flowchart for outputting a source indication digital signal by the device shown in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Source recording medium 2 ... Duplicate recording medium 3 ... Reproduction device 4 ... Mixer 5 ... Input device 6 ... Recording device 7 ... Memory 8 ... Operation circuit 9 ... Addition circuit 10 ... Comparison device 11 ... Input buffer 12 ... Clock timer circuit 13 ... Average value detection circuit 14 ... Change rate detection circuit 15 ... Delay circuit 16 ... Mixing circuit 17 ... CPU 18 ... Output buffer 19 ... Input keyboard 20 ... Memory

Claims (6)

[Claims] An audio / video digital signal is input from a source recording medium (1) storing an audio / video digital signal which becomes an analog audio / video signal when D / A converted to a duplicate recording medium (2). In a recording method for recording an audio / video digital signal on the duplicate recording medium (2), when the audio / video digital signal is input from the source recording medium (1) to the duplicate recording medium (2), the audio / video digital signal is Only when the condition is met, the source indication digital signal identifying the source recording medium (1) is input to the duplicate recording medium (2) together with the audio / video digital signal, and both the audio / video digital signal and the source indication digital signal are duplicated. A recording method for specifying a copied source recording medium, characterized by recording on a recording medium (2). 2. A digital audio / video signal is input to a duplicate recording medium (2) from a source recording medium (1) storing an audio / video digital signal that becomes an analog audio / video signal after D / A conversion. In a recording method for recording an audio / video digital signal on the duplicate recording medium (2), when the audio / video digital signal is input from the source recording medium (1) to the duplicate recording medium (2), the audio / video digital signal is Only when the condition is met, the source indication digital signal identifying the source recording medium (1) is input to the duplicate recording medium (2) together with the audio / video digital signal, and both the audio / video digital signal and the source indication digital signal are duplicated. The digital signal of the duplicate recording medium (2), which is recorded on the recording medium (2) and stores both the audio-video digital signal and the source indication digital signal, is synchronized with the audio-video digital signal of the source recording medium (1). The source recording medium (1) by detecting a difference signal between the digital signals of the source recording medium (1) and the duplicate recording medium (2), and detecting a source indication digital signal from the detected difference signal. A recording method for specifying a copied source recording medium, comprising: 3. In a state where an audio / video digital signal is converted into an analog signal by D / A conversion, only when the level of the analog signal is higher than a set level and is higher than a set change rate, the audio / video 2. The recording method for specifying a copied source recording medium according to claim 1, wherein the origination indicating digital signal is recorded together with the digital signal on the duplicate recording medium. 4. A source recording digital signal is copied to a duplication recording medium.
Set the set level of the audio / video digital signal input to (2)
4. The recording method for specifying a copied source recording medium according to claim 3, wherein the audio / video digital signal is calculated and changed from an average value of D / A converted analog signal levels. 5. An audio / video digital signal is input from a source recording medium (1) storing an audio / video digital signal which becomes an analog audio / video signal when D / A converted to a duplicate recording medium (2). In a recording method for recording an audio-visual digital signal on the duplicate recording medium (2), when inputting the audio-visual digital signal from the source recording medium (1) to the duplicate recording medium (2), at random timing,
The source indication digital signal specifying the source recording medium (1) is input to the duplicate recording medium (2) together with the audio / video digital signal, and both the audio / video digital signal and the source indication digital signal are recorded on the duplicate recording medium (2). A recording method for identifying a copied source recording medium. 6. An audio / video digital signal is input from a source recording medium (1) storing an audio / video digital signal which becomes an analog audio / video signal after D / A conversion to a duplicate recording medium (2). In a recording method for recording an audio-visual digital signal on the duplicate recording medium (2), when inputting the audio-visual digital signal from the source recording medium (1) to the duplicate recording medium (2), at random timing,
A source indication digital signal specifying the source recording medium (1) is input to the duplicate recording medium (2) together with the audio / video digital signal, and both the audio / video digital signal and the source indication digital signal are recorded on the duplicate recording medium (2). The digital signal of the duplicate recording medium (2) storing both the audio-video digital signal and the source display digital signal is compared with the audio-video digital signal of the source recording medium (1) synchronously, and the source recording medium ( Detecting the difference signal between the digital signal of the recording medium (1) and the duplicate recording medium (2), detecting the source indication digital signal from the detected difference signal and identifying the source recording medium (1) A recording method that specifies the source recording medium.