JP3269715B2 - Disc playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk reproducing apparatus for independently reproducing a plurality of disks such as a compact disk.

[0002]

2. Description of the Related Art Generally, in a recording medium on which music such as an analog record or a magnetic tape is recorded, a silent portion is formed between the music recorded on the recording medium and the next music. In addition, the tempo of one song and the tempo of the following song are often different from each other. In particular, when the songs recorded on different recording media are continuously reproduced, the switching of the song is recognized due to the difference in tempo. It is easy and the breaks between songs are noticeable.

[0003] In order to make the break between songs caused by this difference in tempo inconspicuous, a broadcast station, a disco,
There is a switching method used in aerobics studios and the like.

In this switching method, two playback devices such as an analog player and a cassette deck are prepared in advance, and one of the playback devices starts playback of a preceding song, and another playback device during playback of the preceding song. While monitoring the next song played on the headphones with the headphone, adjust the playback speed of the other playback device so that the tempo of this next song matches the tempo of the preceding song,
At the same time when the reproduction of the preceding music by one reproduction device is completed, the reproduction is switched to another reproduction device, and the reproduction of the next music is started based on the reproduction speed adjusted by the other reproduction device.

Therefore, when switching from the preceding music piece to the next music piece, the tempo of the next music piece matches the tempo of the preceding music piece, so that the switching of the music piece caused by the difference between the tempo of the next music piece and the tempo of the preceding music piece becomes inconspicuous. Become smooth.

However, since the operation of adjusting the playback speed of another playback device is performed manually, this speed adjustment requires a high level of skill and intuition of the operator, and many people use the above switching method. It cannot be done easily.

[0007]

As described above, in the conventional switching method for making the switching of the music due to the difference in tempo inconspicuous, the conventional method for matching the tempo of the preceding music with the tempo of the next music is performed. The adjustment work requires advanced technology and intuition, and this adjustment work cannot be easily performed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a disk reproducing apparatus capable of easily realizing a switching method for making the switching of music pieces having different tempos inconspicuous.

[0009]

According to the present invention, there is provided a disk reproducing apparatus comprising: a plurality of reproducing means for independently reproducing a disk such as a compact disk; and a reproducing signal level from a music piece of the disk reproduced by each reproducing means. The beat portion detecting means for detecting a portion having a large reproduction signal and the cycle of a portion having a large reproduction signal level of each of the discs detected by the beat portion detection means are calculated, and the periods of the portions having a large reproduction signal level of each disc match. Playback speed adjusting means for adjusting the playback speed of the disc for each of the playback means, and instructing another one of the playback means to start playback of the disc before the end of the playback of the disc by one of the playback means. Thereby, the music of the disk reproduced by one of the reproducing means is converted to the music of the disk reproduced by the other one of the reproducing means. And a editing means each song during row is edited to a continuous track.

[0010]

The disc reproducing apparatus according to the present invention detects a portion having a high reproduction signal level for each disk and reproduces each of the detected discs such that the periods of the portions having the high reproduction signal level coincide with each other. Adjust the playback speed of the means.

When music recorded on different disks is continuously reproduced, a plurality of disks recording music to be reproduced are prepared, and each disk can be reproduced by a corresponding reproducing means. Will be installed.

Next, a portion where the reproduction signal level of the music to be reproduced first is high and a portion where the reproduction signal level of the music to be reproduced next is high are detected. From the result of this detection, the cycle of the portion where the playback signal level of each song is large is calculated, and the cycle of the portion where the playback signal level of the first song is large matches the cycle of the portion where the playback signal level of the next song is large. The playback speed of each disc is adjusted. After the adjustment of the reproduction speed, the disk is switched.

Therefore, when the disc is switched, the playback speed is adjusted by the playback speed adjusting means so as to match the tempo of the preceding song with the tempo of the next song. Is not required, and a method for making the switching of music pieces having different tempos inconspicuous can be easily realized.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a disk reproducing apparatus according to the present invention.

[0016] As shown in FIG.
It has two reproducing units 2 for reproducing signals recorded on a compact disc 1. Each reproducing unit 2 irradiates the recording surface of the compact disk 1 with a laser beam and reads a signal recorded on the recording surface from the reflected light, and a spindle motor for rotating the compact disk 1. And 4.

The output signal of the optical pickup 3 is given to a signal processor 5. The signal processor 5 converts the output signal of the optical pickup 3 into pulse-coded and modulated data (hereinafter referred to as PCM data), and outputs PCM data at a read speed determined according to the clock from the clock generator 6. At the same time, it outputs subcode data Q recorded in the subcode area and time data indicating the maximum inversion interval.

The subcode data Q is provided to the microcomputer 7 and a main microcomputer 18 described later. The microcomputer 7 controls the frequency of the clock generated from the clock generator 6 based on the subcode data Q, and generates a control signal for moving the optical pickup 3 to the recording position of the signal to be reproduced on the compact disc 1. I do.

The time data indicating the maximum inversion interval is given to the CLV servo mechanism 8. The CLV servo mechanism 8 controls the rotation speed of the spindle motor 4 based on the time data indicating the maximum reversal interval so that the relative speed (linear speed) between the optical pickup 3 and the recording track of the compact disc 1 becomes constant.

The PCM data is provided to a D / A converter 9. The D / A converter 9 converts the PCM data into an analog signal and outputs this analog signal as a reproduction signal.

The reproduction signal from each reproduction unit 2 is a corresponding VC
A10 and to switch 11. Each VCA 10 attenuates the level of the reproduced signal input thereto at an attenuation rate specified by the main microcomputer 18, and outputs the attenuated reproduced signal to the synthesizer 12. The synthesizer 12 adds the reproduced signals from the respective VCAs 10 and outputs the added signal via a terminal 13.

The switch 11 selects one of the reproduction signals from the reproduction units 2. The selection operation of the switch 11 is controlled by a control signal from the main microcomputer 18.

The reproduced signal selected by the switch 11 is supplied to bandpass filters (hereinafter, referred to as BPFs) 14 and 15, respectively. The BPF 14 is a filter whose bandwidth is set to f1, and the BPF 15 is a filter whose bandwidth is set to f2. F1 set in the BPF 14 is larger than f2 set in the BPF 15, and this f2 is set so as to separate a beat component of a kick drum of about 100 Hz.

The output signal from each of the BPFs 14 and 15 is given to a switch 16, and the switch 16
One of the five output signals is selected. The selection operation of the switch 16 is controlled by a control signal from the main microcomputer 18.

The signal selected by the switch 16 is provided to an envelope detector 17. Envelope detector 17
Detects the envelope of the signal from the switch 16 and converts this signal into a DC voltage signal having strength information.

The DC voltage signal from the envelope detector 17 is supplied to the main microcomputer 18 together with the subcode data Q from each reproducing unit 2. The main microcomputer 18 controls the switches 11 and 16 based on the sub-code data Q and the DC voltage signal from the envelope detector 17 and controls each VCA 10
The setting of the decay rate and the operation timing thereof, and the adjustment of the reproduction speed for each reproduction unit 2 when switching from one reproduction unit 2 to the other reproduction unit 2 are performed.

Next, the operation of the compact disc reproducing apparatus will be described with reference to the drawings. FIG. 2 is a flowchart for explaining the beat detection operation of the disc reproducing apparatus of FIG. 1, FIG. 3 is a diagram showing waveforms before and after a subtraction process performed at the time of detecting a beat of the disc reproducing apparatus of FIG. 1, and FIG. FIG. 5 is a flowchart for explaining the switching operation of the compact disk of the disk reproducing device of FIG. 1, and FIG. 5 is a diagram for explaining the operation of the VCA of the disk reproducing device of FIG.

First, a predetermined compact disc 1 is placed in a state in which each of the reproducing sections 2 can reproduce each of them. Then
Playback music is designated for each playback unit 2. When the designation of the music to be played is completed, a cross point is detected through a beat detection process for detecting a portion of the music to be played, which has a high playback signal level, and a base pattern determination process for determining a base pattern from the result of the detection process. Cross point determination processing to be determined is performed.

First, a sampling process for extracting a candidate for a cross point for a preceding tune reproduced by one reproducing unit 2 is started. With the start of this sampling process, the attenuation rate of each VCA 10 is
8 sets the level of the output signal to 0, and the main microcomputer 18 switches each switch 1
A control signal for the first and the second 16 is generated. A switch 11 selects a reproduction signal from one of the reproduction units 2 based on the control signal, and a switch 16 selects a BPF 1 based on the control signal.
4 is selected.

The main microcomputer 18 receives the reproduced signal from the period from 10 seconds before the end of the preceding music to the end thereof via the envelope detector 17. The main microcomputer 18 samples the DC voltage signal from the envelope detector 17 and extracts a sampling point as a cross point candidate.

Next, a sampling process for extracting a cross point candidate for the next music piece reproduced by the other reproduction section 2 is started. The switch 11 selects a reproduction signal from the other reproduction unit 2 based on a control signal from the main microcomputer 18, and the switch 16 selects an output signal of the BPF 14 based on the control signal.

A reproduction signal from the start of the next music is taken into the main microcomputer 18 via the envelope detector 17. The main microcomputer 18 starts a sampling operation from the start of the next music piece, and extracts sampling points that are candidates for cross points.

When the extraction of the cross point candidates is completed, beat detection processing is performed, and this beat detection processing is performed for each music reproduced by each reproduction unit 2.

First, the beat detection processing for the music reproduced by one of the reproducing units 2 is started. With the start of the beat detection processing, the attenuation rate of each VCA 10 is set so that the level of the output signal becomes 0, and the main microcomputer 18 generates a control signal for each of the switches 11 and 16. The switch 11 selects a reproduction signal from one reproduction unit 2 based on the control signal, and the switch 16 selects an output signal of the BPF 15 based on the control signal.

The signal selected by the switch 16 is a reproduction signal corresponding to 6 seconds immediately before the end of the music reproduced by one reproduction unit 2. The signal from the switch 16 is taken into the envelope detector 17. Envelope detector 17
As shown in FIG. 3A, detects an envelope of a signal captured therein, and generates a DC voltage signal indicating strength information of the captured signal based on the detected envelope.

The DC voltage signal generated by the envelope detector 17 is supplied to the main microcomputer 18 together with the subcode data Q from one of the reproducing sections 2, and the main microcomputer 18 performs beat detection processing.

In the beat detection processing, as shown in FIG.
The DC voltage signal for 6 seconds from the envelope detector 17 is taken into the main microcomputer 18 (step 101). In addition, 6 from the envelope detector 17
The DC voltage signal for the second is a signal corresponding to the reproduction signal for 6 seconds before the end of the music from one reproduction unit 2.

Next, from the taken DC voltage signal,
A process of subtracting a DC voltage signal having a time difference of about 0.1 second from the DC voltage signal is performed (step 10).
2). By this subtraction processing, the waveform of the DC voltage signal is converted into a waveform from which a value directly representing the peak amount is obtained, as shown in FIG.

After the subtraction process, a process for detecting the peak from the waveform generated by the subtraction process is performed.
This peak detection processing is sequentially performed from the head of the waveform obtained by the subtraction processing, and the first peak is detected.
The level and address of the first peak are stored in a predetermined storage area, and 1 is added to the first peak as its appearance number (step 103). Next, it is determined whether or not the peak appearance number is smaller than 16 (step 105). When the peak appearance number is smaller than 16, processing for detecting the next peak is performed.

When the next peak is detected, the level and address of the next peak are held in a predetermined storage area, and the next peak is given 2 as its appearance number (step 103). . The level of the next peak is compared to the first peak level (step 104). When the level of the next peak is higher than the first peak level by -12 db or more, it is determined whether or not the peak appearance number is smaller than 16 (step 105). When the peak appearance number is smaller than 16, processing for detecting the next peak is performed.

When the level of the detected peak is lower than the level of the first peak by -12 dB, or when the peak appearance number indicating the number of detected peaks is smaller than 16, the peak detection process ends.

After the peak detection processing, the times different from each other 2
The process of selecting one peak is performed (step 10).
6). In this peak selection process, each detected peak is divided into a first half and a second half, and a first peak indicating the maximum level is extracted from among the peaks in the first half, and 2 seconds from the first peak. A second peak which is farther away and indicates the maximum level is extracted from the latter half.

Next, the number of steps n (integer) is set to 1 (step 107). A base pattern is generated by dividing a time between two peaks (including the first peak and the second peak) between the first peak and the second peak into n equal parts (step 108). After the generation of the base pattern, evaluation is performed on the matching between the base pattern and each sample point sampled as a cross point candidate in advance (step 109). When each sample point rides on each step of the base pattern, an evaluation is made that the base pattern is compatible.

Next, the number of steps n is set to 2 to generate a base pattern (step 108) and evaluate the matching between the base pattern and the sample points (step 10).
9) is performed. Similarly, generation of a base pattern (step 108) and evaluation of matching between the base pattern and the sample points (step 109) are performed until the number of steps n becomes 8.

After the generation of the base pattern with the number of steps n = 8 (step 108) and the evaluation of the matching between the base pattern and the sample points (step 109), the base pattern obtained for each number of steps n is completed. Based on the evaluation of the matching, it is determined whether or not there is a suitable base pattern (step 11).
2).

When it is determined that there is a compatible base pattern, a base pattern including a maximum peak is extracted from the compatible base pattern, and a cross point is determined based on the extracted base pattern. (Step 113). The determined cross point is registered (step 114).

If it is determined that there is no compatible base pattern, the cross point is determined by resetting the number of steps n (step 115). , A process of determining a cross point (step 116) or a manual input process (step 117) is selected.

In the process of step 115, the number of steps n is set again to twice the above value, and
The cross point is determined by performing the same processing as in steps # 112.

In step 116, the crossing point is determined by changing the position of the sampling location to a position several seconds away and performing the same processing as in steps 101 to 112 described above.

In the process at step 117, the operator directly listens to the music reproduced by each reproduction unit 2, extracts candidate cross points, inputs the extracted cross points, and then re-enters the main point. The microcomputer 18 evaluates the matching with the beat pattern, and determines and registers the cross point based on the result of the evaluation.

Next, the operation after the completion of the registration of the cross point will be described with reference to FIGS.

First, when the address of the preceding tune being reproduced by one reproducing unit 2 is 10 seconds before the cross point, as shown in FIGS. 4 and 5, the next reproduction by the other reproducing unit 2 is performed. The song is on standby. Next, the time Tp at which the preceding song reaches the cross point is monitored (step 20).
2). When the time Tp becomes 10 seconds or less, the other reproducing unit 2
Is released from the standby state for the next song (step 20).
3).

After the standby state of the next music piece is released from the other reproduction section 2, the time until the cross point of the next music piece is detected (step 204). The reproduction speed of the next music piece is adjusted by the difference between the time to the cross point of the preceding music piece and the time to the cross point of the next music piece (step 205). The adjustment of the reproduction speed is performed by changing the clock frequency for reading the reproduction signal. For example, as shown in FIG. 5, when the difference between the time to the crossing point of the preceding music piece and the time to the crossing point of the next music piece is 0.5 seconds, the clock frequency becomes 10%.
It is incremented by one minute and a difference of 0.5 seconds is absorbed in about 5 seconds.

Next, the time Tn to the crossing point of the next music piece is monitored (step 206), and when the time Tn to the crossing point of the next music piece becomes 1 second or less, a fade-in operation for the next music piece is performed (step 207). ). In the fade-in operation for the next song, as shown in FIG.
0 is gradually reduced, and as the attenuation rate decreases, the signal passing amount in the other VCA 10 gradually increases until it reaches 100%.

After fade-in of the next song, the time Tp until the cross-fade point of the preceding song is monitored (step 2).
08) When the time Tp becomes 0 second or less, the fade-out operation for the preceding music is started (step 209).
In the fade-out operation for the preceding tune, as shown in FIG. 5, an instruction is issued to one of the VCAs 10 to gradually increase the attenuation rate. Is 100
% To 0%.

After fade-out of the preceding song, a reproduced sound of only the next song is obtained, and it is difficult to recognize switching of songs having different tempos.

[0057]

As described above, according to the disk reproducing apparatus of the present invention, it is possible to easily realize a method for making the switching of music pieces having different tempos inconspicuous.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a disk reproducing apparatus according to the present invention.

FIG. 2 is a flowchart for explaining a beat detection operation of the disc reproducing apparatus of FIG. 1;

3 is a diagram showing waveforms before and after a subtraction process performed when a beat is detected by the disc reproducing apparatus in FIG. 1, respectively.

FIG. 4 is a flowchart for explaining a disc switching operation of the disc reproducing apparatus of FIG. 1;

FIG. 5 is a diagram for explaining an operation of the VCA of the disc reproducing apparatus of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compact disk 2 Reproduction part 3 Optical pickup 4 Motor 5 Signal processor 6 Clock generator 7 Microcomputer 8 CLV servo mechanism 10 VCA 11, 16 Switch 12 Adder 14, 15 BPF 17 Envelope detector 18 Main microcomputer

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 27/034 G11B 19/02 501

Claims (2)

(57) [Claims] A plurality of reproducing means for independently reproducing a disc such as a compact disc; a beat detecting means for detecting a portion having a high reproduction signal level from music on the disc reproduced by each reproducing means; Calculate the cycle of each portion of the disk where the reproduction signal level detected by the beat portion detection unit is large, and adjust the reproduction speed of the disk with respect to each reproduction unit so that the period of the portion where the reproduction signal level of each disk is large matches. A reproducing speed adjusting means for adjusting; and before the reproduction of the disc is completed by one of the reproducing means, by instructing the other one of the reproducing means to start reproducing the disc, the reproduction is performed by one of the reproducing means. When transitioning from the music on the disc to the music on the disc reproduced by the other one of the reproduction means, each music is a continuous music. Disk reproducing apparatus, characterized in that it comprises a editing means collecting for. 2. The image processing apparatus according to claim 1, wherein said editing means includes: synthesizing means for synthesizing reproduction signals from the respective discs at a corresponding ratio; The disk playback device according to claim 1.