JP2005025875A - Reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reproducing apparatus with which an always optimum higher harmonics addition effect can be obtained by easily specifying the upper limit frequency of reproduction of an original signal subjected to band limitation at the time of adding higher harmonics to the original signal. <P>SOLUTION: A sound source mode detecting means 8 of a control means 3 acquires sound source mode information of a musical piece from a sound source 1. A higher harmonics addition parameter selection means 11 selects the parameter to be set according to the sound source mode of the musical piece from the inside of a higher harmonics addition parameter holding means 10 and transmits the same to a higher harmonics addition means 6. The higher harmonics are added to the original signal by using the parameter received by the higher harmonics addition means 6, by which the always optimum higher harmonics addition effect is obtained according to the sound source mode. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a music playback apparatus represented by a compact disc (hereinafter referred to as CD) player, a mini disc (hereinafter referred to as MD) recorder, and the like.
[0002]
[Prior art]
In general, a digital audio signal has a high sound reproducible band limited by a sampling frequency and a bit rate. As a technique for adding a harmonic to the band-limited signal to extend the reproduction band, there is one described in Japanese Patent Laid-Open No. 7-93900. This is because an oversampling low-pass filter extracts only the read original signal component of 1/2 or less of the sampling frequency fs of the PCM digital audio signal obtained by reading from the recording medium, and this extracted audio signal and its absolute value component A harmonic component is generated by multiplying the signal including the signal, and a harmonic component of fs / 2 or more is extracted from the harmonic component and is superimposed on the read original signal component.
[0003]
On the other hand, in order to add harmonics, it is necessary to specify the upper limit frequency of reproduction of a band-limited signal. In CD, the upper limit frequency is fixed at about 20 kHz, but as a means for specifying the upper limit frequency when the reproduction upper limit frequency cannot be fixed as in MD, it is described in Japanese Patent Application Laid-Open No. 2001-356788. There is.
[0004]
[Patent Document 1]
JP-A-7-93900 (full text)
[Patent Document 2]
JP 2001-356788 A (full text)
[0005]
[Problems to be solved by the invention]
The means for specifying the reproduction upper limit frequency described in Patent Document 2 requires a spectrum calculation process in real time during reproduction. However, this method requires a CPU with a high processing speed, increases the cost, and is inevitable. In addition, power consumption increases.
[0006]
The present invention provides means for specifying a reproduction upper limit frequency for adding harmonics without performing real-time arithmetic processing during reproduction in a reproduction apparatus with limited processing speed and power consumption, such as a portable audio device. It was made for the purpose of providing.
[0007]
[Means for Solving the Problems]
In order to solve this problem, the playback device of the present invention has a plurality of sound source modes having different frequency bands as a basic configuration, and generates harmonics so that a high frequency playback signal does not become unnatural when the sound source is played back. A reproduction apparatus configured to add a harmonic addition parameter holding means for holding a parameter for adding harmonics optimum for a frequency band of each reproduction signal in the plurality of sound source modes; and a reproduction signal of the sound source. Sound source mode detection means for detecting a sound source mode, and parameter selection means for selecting the harmonic addition parameter held in the harmonic addition parameter holding means in correspondence with the sound source mode being reproduced detected by the sound source mode detection means And harmonics corresponding to the harmonic addition parameters selected by the parameter selection means and added to the sound source signal being played back And an optimum parameter for adding harmonics only by the sound source mode information of the music without performing arithmetic processing on the audio signal. It has the effect of being able to.
[0008]
In addition, the playback apparatus of the present invention can be configured so that a plurality of harmonic parameters can be set in each sound source mode in the above basic configuration, whereby the intensity of the harmonic addition effect can be changed at any time by a user operation. Has an effect.
[0009]
The playback apparatus of the present invention is characterized in that, in the basic configuration described above, the track mode of the music recorded on the MD is set as the sound source mode. According to this configuration, recording is performed in a different track mode. In addition, even when a plurality of music pieces are continuously played back, it is possible to easily set optimal harmonic addition parameters.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings when applied to MD.
[0011]
(Embodiment 1)
1 is a block diagram of a reproduction apparatus according to Embodiment 1 of the present invention, FIG. 2 is a schematic diagram of frequency characteristics of a reproduction signal in the SP mode and the MONO mode, FIG. 3 is a schematic diagram of frequency characteristics of the reproduction signal in the LP2 mode, and FIG. Is a schematic diagram of frequency characteristics of a reproduction signal in the LP4 mode, and FIG. 5 is a flowchart of harmonic addition parameter selection and setting by the control means during reproduction.
[0012]
In the reproducing apparatus of FIG. 1, a sound source 1 using a storage medium such as an MD disk, a reproducing unit 2 that reproduces a signal from the sound source 1 using a pickup (not shown), a control unit 3 that controls at least the reproducing unit 2, and an audio of the reproducing unit 2 Audio output means 4 such as a speaker or headphones for converting the output into audio is provided.
[0013]
The reproduction means 2 obtains a reproduction signal from the sound source 1 by a pickup (not shown), digitizes it, performs EFM demodulation, error correction, etc. and outputs a digital audio signal, and outputs the digital audio signal from the demodulation decoding means 5 Harmonic adding means 6 for adding harmonics to the audio signal, and amplifying means 7 for converting the digital audio signal added with the harmonics by the harmonic adding means 6 into an analog digital audio signal and amplifying it to output to the audio output means 4 Have
[0014]
Since the configuration and principle of the harmonic wave adding means 6 are already known techniques disclosed in Patent Document 1 and the like, description thereof will be omitted.
[0015]
The control means 3 detects the track mode which is the sound source mode corresponding to the music from the TOC / UTC data obtained from the reproduction signal of the sound source 1, and stores the detected track mode in correspondence with the music. Corresponding to each track mode, the harmonics stored in a non-volatile memory such as a ROM are combined with the cutoff frequency and cutoff characteristics of the high-pass filter that limits the band of harmonics, the harmonic addition level for the original signal, etc. Wave addition parameter holding means 10 and parameter addition means 11 for selecting a harmonic addition parameter corresponding to the music to be reproduced from the harmonic addition parameter holding means 10. The harmonic addition characteristic switching input key 12 is used by the user for switching the harmonic addition characteristic in the second embodiment.
[0016]
The operation of the playback apparatus of the present invention configured as described above will be described below. The MD standard has four track modes SP, MONO, LP2, and LP4 as sound source modes. In FIG. 2 showing the frequency characteristics of the reproduction signal in the SP mode and the MONO mode, the solid line 13 shows the frequency characteristics of the original signal before adding the harmonics, and the solid line 14 shows the frequency characteristics of the harmonics to be added. In FIG. 3 showing the frequency characteristic of the reproduction signal in the LP2 mode, the solid line 15 shows the frequency characteristic of the original signal before adding the harmonic wave, and the solid line 16 shows the frequency characteristic of the harmonic wave to be added. In FIG. 4 showing the frequency characteristics of the reproduction signal in the LP4 mode, the frequency characteristics of the original signal before adding the harmonic are shown by a solid line 17 and the frequency characteristics of the harmonic to be added are shown by a solid line 18.
[0017]
As shown in FIGS. 2 to 4, the upper limit frequency of the MD reproduction signal is generally limited to about 16 kHz for SP · MONO, about 14 kHz for LP2, and about 12 kHz for LP4. Therefore, when adding a harmonic, it is necessary to limit the harmonic to a band equal to or higher than these upper limit frequencies and add it to the original signal. In the present embodiment, the harmonic addition parameter for each track mode is held in advance in the harmonic addition parameter holding means 10 of the control means 3.
[0018]
2 to 4, the frequency characteristics of the original signal before adding the harmonics and the frequency characteristics of the harmonics to be added are expressed as crossing over, but the two should not be superimposed. There is no problem.
[0019]
When the MD disk is inserted into a disk reading means (not shown), the reproducing means reads the TOC / UTC data recorded on the disk using a pickup (not shown), and the read TOC / UTC data is demodulated according to an instruction from the control means 3. The data is stored in the RAM 9 in the control means 3 from the decoding means 5. By saving the TOC / UTC data in the RAM 9, it becomes possible to always refer to the track mode of all the songs recorded on the disc, and the track mode can be detected without accessing the TOC / UTC area of the disc even during playback of the song. It can be carried out.
[0020]
In FIG. 5, when the reproduction of an arbitrary music recorded on the disk is started in step 51, the control means 3 uses the sound source mode detection means 8 in step 52, and the control means 3 reads the music from the TOC / UTC data held in the RAM 9. Read the track mode. Next, the harmonic addition parameter corresponding to the read track mode is selected from the harmonic addition parameter holding means 10 set and held in advance using the harmonic addition parameter selection means 11. In step 53, it is examined whether or not the sound source mode is SP. If it is SP, an SP parameter is selected in step 54. If the sound source mode is not SP in step 53, it is examined whether or not it is MONO in step 55. If it is MONO, a parameter for MONO is selected in step 56. If the sound source mode is not MONO in step 55, it is examined in step 57 whether it is LP2, and if it is LP2, a parameter for LP2 is selected in step 58. If the sound source mode is not LP2 in step 57, it is examined in step 59 whether or not it is LP4. If LP4, LP4 parameters are selected in step 60. If not LP4 in step 59, the process returns to step 53. If the parameter is set in steps 54, 56, 58, 60, the parameter is set in the harmonic adding means 6 of the reproducing means 2 in step 61. The harmonic addition means 6 of the reproduction means 2 sets, as the harmonic addition parameters set by the control means 3, the cutoff frequency and cutoff characteristics of the high-pass filter that limits the band of the harmonics, and the harmonic addition level for the original signal. Then, the reproduction signal obtained by adding the harmonic to the original signal by the harmonic adding means 6 is converted into an analog signal by the amplifying means 7, amplified and output to the audio output means 4. When the tune being played is finished or the user switches to playback of another tune, the control means 3 uses the sound source mode detection means 8 to read the track mode of the tune again from the RAM 9 and perform the same procedure as above. The harmonic addition parameter is set in the harmonic addition means 6 of the reproducing means 2.
[0021]
As described above, according to the present embodiment, the harmonic addition parameters are automatically switched according to the track mode of the music to set the cutoff frequency and cutoff characteristics of the high-pass filter and the harmonic addition volume level for the original signal. Therefore, it is possible to always obtain the optimum harmonic addition effect.
[0022]
(Embodiment 2)
Next, FIG. 6 shows a schematic diagram of switching of harmonic addition characteristics in the second embodiment. In FIG. 6, the frequency characteristic of the original signal before addition of harmonics in a certain track mode is added by a solid line 19. The frequency characteristics of the harmonics are indicated by solid lines 20a, 20b, and 20c. The playback apparatus uses the configuration of FIG. 1 as in the first embodiment.
[0023]
In the present embodiment, several harmonic addition parameters are prepared in advance in the control means 1 for each track mode. When the user performs an operation of switching the harmonic addition characteristic by using the harmonic addition characteristic switching input key 12 during reproduction or stop, the control means 3 adds the harmonic addition parameter having the corresponding characteristic to each track mode. Select from parameter holding means 10.
[0024]
Thereafter, the harmonic selection parameter is selected by the parameter selection unit 11 according to the track mode of the music to be reproduced or reproduced, and the harmonic addition parameter is set in the harmonic addition unit 6 of the reproduction unit 2 The characteristics of adding harmonics can be switched.
[0025]
In the present embodiment, the harmonic addition parameter is selected by the user from several patterns prepared in advance. However, in order to further increase the degree of freedom of characteristic selection, the user selects the harmonic parameter itself. The configuration to specify is also conceivable.
[0026]
Further, in each of the above embodiments, the harmonic addition parameter changes not only the cutoff frequency and cutoff characteristics of the exemplified high-pass filter and the harmonic addition volume level with respect to the original signal, but also, for example, the harmonic addition volume level for each frequency band. Etc. may be added.
[0027]
Further, in each of the above embodiments, the case of MD has been described as an example. However, the present invention can also be applied to a CD, and can also be applied to a playback device that can obtain a sound source mode from a sound source in the same manner as each of the above embodiments. It is.
[0028]
【The invention's effect】
As described above, according to the playback device of the present invention, the sound source mode of the music is detected from the sound source, the harmonic parameter is selected according to the sound source mode, and the sound source signal being played back is corresponding to the harmonic parameter. Therefore, an advantageous effect that an optimum harmonic addition effect can always be obtained is obtained, and the user can select a harmonic parameter.
[Brief description of the drawings]
FIG. 1 is a block diagram of a playback apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram of frequency characteristics of a playback signal when the MD track mode is SP mode or MONO mode. Reproduction signal frequency characteristic schematic diagram when the mode is LP2 mode [FIG. 4] Reproduction signal frequency characteristic schematic diagram when MD track mode is LP4 mode [FIG. Flow chart of parameter selection and setting [FIG. 6] Schematic diagram of switching harmonic addition characteristics in Embodiment 2 of the present invention [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sound source 2 Reproduction | regeneration means 3 Control means 4 Audio | voice output apparatus 5 Demodulation decoding means 6 Harmonic addition means 7 Amplification means 8 Sound source mode detection means 9 RAM
10 Harmonic addition parameter holding means 11 Parameter selection means 12 Input key for switching harmonic addition characteristics

Claims (3)

It has multiple sound source modes with different frequency bands,
A reproduction apparatus configured to add harmonics so that a high frequency reproduction signal does not become unnatural when reproducing a sound source,
Harmonic addition parameter holding means for holding harmonic addition parameters optimal for the frequency band of each reproduction signal of the plurality of sound source modes;
Sound source mode detecting means for detecting a sound source mode from the reproduction signal of the sound source;
Parameter selection means for selecting the harmonic addition parameter held in the harmonic addition parameter holding means in accordance with the sound source mode being reproduced detected by the sound source mode detection means;
A reproduction apparatus comprising: harmonic addition means for generating a harmonic corresponding to the harmonic addition parameter selected by the parameter selection means and adding the harmonic to a sound source signal being reproduced. The reproduction apparatus according to claim 1, wherein the harmonic parameter holding means can further set a plurality of harmonic addition parameters in each sound source mode. 2. The reproducing apparatus according to claim 1, wherein the sound source mode detecting means sets the track mode of the music recorded on the MD as a sound source mode.

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