JP2006085843A - Recording apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of dubbing from a first recording medium into a second recording medium at high speed while applying adjustment processing such as equalization. <P>SOLUTION: A high-speed adjusting recording apparatus is provided with: a reproducing means 1 for reproducing digital audio data recorded in the first recording medium at specified speed higher than normal speed and outputting a high-speed digital sound signal; a digital signal processing means 4 capable of applying the specified adjustment processing to the high-speed digital sound signal at corresponding speed to output an adjusted high-speed digital sound signal; and a recording means 2 capable of recording the adjusted high-speed digital sound signal to the second recording medium at the specified high speed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a recording apparatus and method capable of performing dubbing at high speed while performing adjustment processing such as equalizing processing.

  Conventionally, it has a function of recording and playing back a compact disc (hereinafter referred to as “CD”) and a mini disc (hereinafter referred to as “MD”), and at double speed or quadruple speed from CD to MD. There is known an audio system having a dubbing function and a function of performing an adjusting process such as an equalizing process on an analog audio signal obtained by reproduction.

  FIG. 2 is a block diagram showing an example of such a conventional audio system. In the figure, 21 is a CD playback unit that plays back information recorded on a CD and outputs it as an audio signal, and 22 is an MD recording / playback that performs recording on the MD and playback of the signal recorded on the MD. Part. The CD reproducing unit 21 outputs the digital audio signal obtained by reproduction as it is or outputs it after performing D / A conversion.

  Reference numeral 23 denotes an AD conversion unit that converts an analog audio signal from the CD reproduction unit 21 or the MD recording / reproduction unit 22 into a digital audio signal. Reference numeral 24 denotes an adjustment process such as equalizing for the digital audio signal from the AD conversion unit 23. It is a digital signal processor (hereinafter referred to as “DSP”). The DSP 24 constitutes a digital filter that boosts or cuts a band centered on each predetermined frequency, and performs equalization by changing the characteristics of each filter as required.

  Reference numeral 25 denotes a DA converter that converts a digital audio signal from the DSP 24 into an analog audio signal. Reference numeral 26 denotes an audio output unit that amplifies the analog audio signal from the DA converter 25, converts it into an audio signal by a speaker or the like, and outputs it. It is.

  Reference numeral 27 denotes a microcomputer (hereinafter referred to as “microcomputer”) that controls the CD playback unit 21, MD recording / playback unit 22, DSP 24, and the like. Reference numeral 28 denotes an operation unit that functions as an interface between the microcomputer 27 and the user. . The user can give instructions to the microcomputer 27 via the operation unit 28 regarding the operation of the CD playback unit 21, the MD recording / playback unit 22, the contents of equalizing processing in the DSP 24, and the like.

  In this configuration, when the user instructs dubbing from CD to MD at 4 × speed, the microcomputer 27 instructs the CD playback unit 21 to perform playback at 4 × speed. Further, the MD recording / reproducing unit 22 is instructed to record the digital audio signal from the CD reproducing unit 21 at a quadruple speed. The digital audio signal obtained by the reproduction is sent to the MD recording / reproducing unit 22 as it is, and is recorded at a quadruple speed on the MD in the MD recording / reproducing unit 22. As a result, dubbing is performed at a quadruple speed.

  On the other hand, when instructed to perform dubbing with an adjustment process such as equalizing, the microcomputer 27 instructs the CD playback unit 21 to perform playback at the normal speed of 1 × speed. In addition, the MD recording / reproducing unit 22 is instructed to record the digital audio signal from the DSP 24 at a single speed. An analog audio signal obtained by reproduction is sent to the AD converter 23. The AD converter 23 converts this analog audio signal into a digital audio signal and sends it to the DSP 24. The DSP 24 performs adjustment processing such as equalizing on the digital audio signal.

  The characteristics of the digital filter in the DSP 24 at the time of the adjustment process are determined by parameters sent from the microcomputer 27 based on settings made in advance via the operation unit 28. The digital audio signal that has been subjected to the adjustment process is recorded on the MD at the normal single speed in the MD recording / reproducing unit 22.

A technique related to equalizing using a DSP is known from Patent Document 1 and the like. Further, a technique relating to 4 × speed dubbing from CD to MD is known from Patent Document 2 and the like.
Japanese Patent Laid-Open No. 11-1222056 Japanese Patent Laid-Open No. 2001-210009

  However, according to the above-described prior art, when dubbing is performed while performing equalizing processing or the like, there is a problem that dubbing takes a long time because dubbing is performed at a single speed.

  An object of the present invention is to provide a technique capable of performing dubbing from a CD or the like to an MD or the like at high speed while performing adjustment processing such as equalizing in view of the problems of the prior art.

  In order to achieve the above object, a recording apparatus according to a first invention reproduces digital audio data recorded on a first recording medium at a second speed higher than the first speed, and performs high-speed digital audio. A reproduction means capable of outputting a signal, and a digital signal capable of performing a predetermined adjustment process at a second speed corresponding to the high-speed digital voice signal corresponding to the second speed and outputting the adjusted high-speed digital voice signal. It is characterized by comprising signal processing means and recording means capable of recording the adjusted high-speed digital audio signal on the second recording medium at a speed corresponding to the second speed.

  The recording apparatus according to a second aspect of the present invention is the recording apparatus according to the first aspect, wherein the digital signal processing means is used for the adjustment process applied to the digital audio signal reproduced at the first speed when the adjustment process is performed. Instead of the program, a program having a smaller number of steps corresponding to the second speed adjustment process is executed.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the digital signal processing means reproduces the bit clock accompanying the normal speed digital audio signal that is reproduced by the reproducing means at the first speed. A PLL circuit that generates a digital signal processing operation clock as a reference signal is provided, and when performing adjustment processing on the high-speed digital audio signal, a digital signal processing operation clock having the same frequency as the digital signal processing operation clock is obtained. It is characterized by switching the multiplication factor in the PLL circuit.

  According to a fourth aspect of the present invention, there is provided a recording method for reproducing digital audio data recorded on a first recording medium at a second speed higher than the first speed and outputting a high-speed digital audio signal. A digital signal processing step of applying a predetermined adjustment process to the digital audio signal at the second speed at a corresponding high speed and outputting the adjusted high-speed digital audio signal; and the adjusted high-speed digital audio signal A recording step of recording on the second recording medium at a speed corresponding to the second speed.

  According to the present invention, it is possible to perform dubbing at a high speed higher than the normal speed while accompanying an adjustment process such as equalizing.

  The first recording medium and the second recording medium described above are digital recording media such as music CD (CD-DA), DVD-Audio, DAT, MD, and the like. As the first speed, for example, 1 × speed corresponds. Examples of the second high speed include double speed and quadruple speed. Examples of the predetermined adjustment process include an equalizing process and a sound field control process. As the digital signal processing means, for example, a DSP that forms an IIR type digital filter based on a given filter coefficient and performs equalizing processing or the like is applicable.

  In the configuration of the present invention described above, when dubbing from the first recording medium to the second recording medium, the high-speed digital audio signal output from the reproducing means is used at a corresponding high speed by the digital signal processing means. Adjustment processing is performed. The adjusted high-speed digital audio signal is recorded on the second recording medium at a high speed by the recording means. There is no need to convert to an analog audio signal in the middle of the dubbing path. Therefore, as compared with the conventional case, analog audio signals reproduced at normal speed and D / A converted are converted to A / D converted and then subjected to adjustment processing and recorded on the second recording medium. Dubbing is performed.

  FIG. 1 is a block diagram showing the configuration of an audio system according to an embodiment of the present invention. As shown in the figure, this apparatus reproduces digital audio data recorded on a CD at a quadruple speed and outputs a quadruple speed digital audio signal. The DSP 4 that outputs the adjusted quadruple-speed digital audio signal and the adjusted quadruple-speed digital audio signal are recorded at the quadruple speed with respect to the MD. An MD recording / reproducing unit 2 is provided. The CD playback unit 1, DSP 4, and MD recording / playback unit 2 also support playback, processing, and recording at normal speed or double speed.

  This system also converts an analog audio signal from the CD reproduction unit 1, MD recording / reproduction unit 2, line input terminal 9 and the like into a digital audio signal and supplies it to the DSP 4, and a digital audio signal from the DSP 4 Is converted to an analog audio signal, an analog audio signal from the DA converter 5 is amplified and converted into an audio signal by a speaker or the like, a microcomputer 7 for controlling each unit, and a microcomputer 7 And an operation unit 8 functioning as an interface between the users.

  The CD playback unit 1 causes the optical pickup to follow the recorded CD track, obtains an RF signal through the optical pickup, performs EFM demodulation on the RF signal, and accompanies the reproduced digital audio signal and this. Get the bit clock. The digital audio signal is also D / A converted to output an analog audio signal. Reproduction can be performed at 1 × speed, 2 × speed, and 4 × speed.

  The MD recording / reproducing unit 2 causes the optical pickup to follow the recorded MD track, acquires the RF signal through the optical pickup, performs EFM demodulation on the RF signal, and further performs compression decoding by ATRAC, The reproduced digital audio signal and the bit clock accompanying it are acquired. In addition, it has a function of compressing the input digital audio signal by the ATRAC method, performing EFM modulation, and recording it on the MD via the optical pickup. Recording can be performed at 1 × speed, 2 × speed, and 4 × speed.

  The DSP 4 constitutes a digital filter that boosts or cuts a band centered on each predetermined frequency, and has a function of performing equalization by changing the characteristics of each filter in response to a request from the microcomputer 7. Further, it has a function of performing predetermined sound field control in response to a request from the microcomputer 7. As the DSP 4, one capable of performing adjustment processing such as equalizing processing corresponding to a sampling frequency of 192 [kHz] is used. By using the setting of the sampling frequency of 192 [kHz], the DSP 4 allows the DSP 4 to output the digital sound at the quadruple speed sampling frequency (4 × 44.1 [kHz] = 176.4 [kHz]). Processing can be performed on the signal.

  In the DSP 4, a bit clock (2.822 [MHz] at a normal reproduction speed) from the CD reproduction signal is input as a reference clock to the internal PLL, and has a frequency 24 times that of the bit clock, for example. A DSP operation clock is generated. Further, the upper limit of the frequency that can be processed in the internal PLL is limited to, for example, about 76 [MHz].

  For this reason, when processing a quadruple-speed digital audio signal from the CD playback unit 1, the bit clock frequency is also quadrupled, and if this is multiplied by 24, the above upper limit value will be exceeded. In addition, the frequency of the DSP operation clock is quadrupled. Therefore, in this case, the multiplication rate of the internal PLL is switched to 6 times so that a clock having a frequency 6 times that of the bit clock can be obtained as the master clock.

  Further, the program length of the program executed by the DSP 4 for performing adjustment processing such as equalizing is made different between the normal speed and the quadruple speed. That is, the upper limit of the number of instruction steps of a program that can be executed during one sampling in the DSP 4 is, for example, 1536 steps when the sampling frequency is 44.1 [kHz], 768 steps when the sampling frequency is 88.2 [kHz], and In the case of 176.4 [kHz], it is determined as 384 steps. For this reason, in the case of double speed or quadruple speed, the number of instruction steps of an executable program is limited to 1/2 or 1/4 of the normal speed. If the number of steps is not limited to 384 steps at quadruple speed, the DSP 4 process will overflow.

  Therefore, when processing a normal speed digital audio signal, a program for controlling other sound fields is executed in addition to a program for equalizing processing, but a digital audio signal at double speed or quadruple speed is processed. In some cases, a program for recording the equalized data on the MD is mainly executed, and a program for obtaining other sound field effects (for example, tone control) or a program related to a process with a delay is executed. It will be omitted if necessary.

  The operation unit 8 forms an appropriate graphic user interface so that the user can easily instruct the microcomputer 7 of the contents of adjustment processing such as equalizing processing. As this interface, for example, a graphic equalizer that adjusts the gain for each predetermined frequency band or a parametric equalizer that can also set a center frequency and a bandwidth that has an operation screen in a form often used is adopted. Can do. Moreover, the thing of the form which can designate the characteristic of each frequency band set beforehand by one touch is also employable.

  In this configuration, when the user gives an instruction regarding the contents of the equalizing process or the like through the operation unit 8 and then receives an instruction to perform dubbing at 4 × speed by pressing a one-touch key on the operation unit 8, the microcomputer 7 issues a command to each unit in order to start the dubbing process at 4 × speed. That is, the DSP 4 is supplied with parameters such as filter coefficients necessary for executing the equalizing process, and is instructed to start the process at quadruple speed. The MD recording / playback unit 2 is instructed to start recording at 4 × speed, and the CD playback unit 1 is instructed to start playback at 4 × speed.

  In response to this, the MD recording / reproducing unit 2 starts recording at 4 × speed. The CD playback unit 1 rotates the CD at 4 × speed and starts playback. The DSP 4 loads a 4 × speed program, switches the multiplication rate of the internal PLL to 4 × speed, and starts equalizing processing. Thereby, the digital audio signal of 4 × speed sequentially reproduced in the CD playback unit 1 is subjected to equalizing processing in the DSP 4 at a normal 4 × speed, and the MD recording / playback unit 2 performs quadruple speed with respect to the MD. Will be recorded sequentially.

  When the recording speed is set to quadruple speed, the number of processing steps (program length) performed by the DSP 4 is limited and reduced, so that the voice signal inputted at high speed can be processed and the voice can be played at a speed corresponding to quadruple speed. A signal can be output. For this reason, in the present embodiment, the processing of the DSP 4 is limited only to the processing to be reflected in the recording signal, and other processing, for example, tone control (processing such as bus and treble) is omitted from the instruction to be executed. .

  In this way, dubbing from CD to MD can be performed at a quadruple speed with an equalizing process by the DSP 4. Note that double-speed dubbing can be performed in the same manner while performing equalizing processing by the DSP 4. When dubbing at a normal speed, the digital audio signal that has been subjected to the equalizing process is also supplied to the D / A converter 5 and converted into an acoustic signal via the acoustic output unit 6, thereby allowing the user to monitor. Can be made possible.

  Note that the recording on the MD is performed by compressing the data to 1/5 by the ATRAC method. For this reason, in the case of dubbing at a normal speed, the reproduction of the CD is performed by a continuous reproduction operation, while the recording on the MD is performed by intermittently repeating the recording operation for a predetermined period. . In the case of dubbing at 4 × speed, playback of a CD is performed by rotating the CD at 4 × speed and continuous playback operation, whereas recording to MD is performed by rotating MD at 2 × speed. The recording speed in each recording operation may be doubled as usual, and the number of recording operations per unit time may be increased by four times.

  Further, dubbing at the normal speed is performed by converting the analog audio signal reproduced at the normal speed from the CD reproducing unit 1 into a digital audio signal by the A / D conversion unit 3 and performing an equalizing process on the DSP 4 as in the prior art. The recording / reproducing unit 2 can perform recording at a normal speed while performing the above.

1 is a block diagram showing an audio system according to an embodiment of the present invention. It is a block diagram which shows the audio system which concerns on a prior art example.

Explanation of symbols

1, 2: 1: CD playback unit, 2, 22: MD recording / playback unit, 3, 23: A / D conversion unit, 4, 24: DSP, 5, 25: D / A conversion unit, 6, 26: sound output Part, 27, 27: microcomputer, 8, 28: operation part, 9, 29: terminal.

Claims (4)

Reproduction means capable of reproducing digital audio data recorded on the first recording medium at a second speed higher than the first speed and outputting a high-speed digital audio signal;
A digital signal processing means capable of performing a predetermined adjustment process at a second speed corresponding to the high-speed digital audio signal corresponding to the second speed and outputting the adjusted high-speed digital audio signal;
A recording apparatus comprising: recording means capable of recording the adjusted high-speed digital audio signal on a second recording medium at a speed corresponding to the second speed.   The digital signal processing means performs the second speed adjustment process in place of the program used for the adjustment process applied to the digital audio signal reproduced at the first speed when the adjustment process is performed. The recording apparatus according to claim 1, wherein the recording apparatus executes a program having a corresponding smaller number of steps.   The digital signal processing means includes a PLL circuit that reproduces the reproduction means at a first speed and generates a digital signal processing operation clock using a bit clock accompanying the normal speed digital audio signal to be output as a reference signal, When performing adjustment processing on the high-speed digital audio signal, the multiplication factor in the PLL circuit is switched so that a digital signal processing operation clock having the same frequency as the digital signal processing operation clock is obtained. The recording apparatus according to claim 1 or 2. A reproduction step of reproducing digital audio data recorded on the first recording medium at a second speed higher than the first speed, and outputting a high-speed digital audio signal;
A digital signal processing step of performing predetermined adjustment processing at a corresponding high speed on the digital audio signal at the second speed and outputting the adjusted high-speed digital audio signal;
And a recording step of recording the adjusted high-speed digital audio signal on a second recording medium at a speed corresponding to the second speed.

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