JPH07312022A - Audio mixer - Google Patents

Abstract

PURPOSE:To perform a cross fade procession capable of changing freely the characteristic of the time of a cross fade or of the attenuating or increasing of a volume level and also to perform easily and repeatedly the cross fade procession. CONSTITUTION:The positional signal VPGM of a fader 7 and the positional signal VPST of a fader 8 are converted into operational data DPGM, DPST with an A/D converter 9. The data are stored in a memory 10 in prescribed sampling cycles and simultaneously are supplied to a digital signal processor (a DSP) 3. The voltage of the signal VPST is raised by operating the fader 8 while lowering the voltage of the signal VPGM by operating the fader 7. The output signal SOUT of the DSP 3 is changed over from an audio signal SPGM to an audio signal SPST. This cross fade procession is freely processed according to operations of the fader 7 and the fader 8. The starting signal ST of the fade procession is supplied from a switch part 12 to a microcomputer 11. Data of the memry 10 are read out by the microcomputer 11 to be supplied to the DSP 3. The free fade procession mentioned above is repeatedly carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio mixer for mixing input audio signals to obtain a desired output audio signal.

[0002]

2. Description of the Related Art Conventionally, there is known an audio mixer which digitally mixes a plurality of input audio signals and outputs the processed signals. This audio mixer is used for editing work in, for example, a video tape recorder (hereinafter referred to as "VTR"). FIG. 3 shows an example of the configuration of the audio mixer.

In FIG. 3, 1-1 to 1-n are audio signal input terminals. This audio signal input terminal 1-1 ~
The reproduced audio signal from the reproducing VTR supplied to 1-n is supplied to the matrix switcher 2. The matrix switcher 2 selects two audio signals from the supplied reproduced audio signals. These two selected audio signals are processed by a digital signal processing device (hereinafter referred to as "DSP") as a program audio signal SPGM and a preset audio signal SPST as described later.
3), edited by the DSP 3, and output from the audio output terminal 4 as the audio output signal SOUT.

AB roll editing, which is a general method of VTR editing processing, will be described with reference to FIG. It should be noted that description of the image signal will be omitted here, and only the audio signal will be described.

This AB roll editing is an A-VT for reproduction.
R and the B-VTR for reproduction are alternately reproduced, a reproduction signal is selected and recorded in the recording VTR. In the example shown in FIG. 4, the reproduced audio signals of the three reproducing VTRs are supplied to the matrix switcher 2 shown in FIG. 3, and the two reproduced audio signals are selected and edited. FIG. 4B shows a reproduced audio signal of the first VTR, FIG. 4B shows a reproduced audio signal of the second VTR, and FIG. 4C shows a reproduced audio signal of the third VTR. Also,
FIG. 4D shows an audio signal recorded in the recording VTR.

In FIG. 4, the second VT is set at point P1.
The playback audio signals of R and the third VTR are selected by the matrix switcher 2, and the second up to the point P1.
The reproduced audio signal of the VTR is recorded, and the reproduced audio signal of the third VTR is recorded from the point P1. At point P2, the reproduced audio signals of the first VTR and the third VTR are selected, and the reproduced audio signal of the third VTR is recorded up to point P2, and the reproduced audio signal of the first VTR is recorded from point P2. At point P3, the playback audio signals of the first VTR and the third VTR are selected as at point P2, the playback audio signal of the first VTR is recorded up to point P3, and the playback audio signal of the third VTR is played from point P3. The signal is recorded.

In the AB roll editing, the audio mixer causes the reproduced audio signal of the VTR currently being reproduced (hereinafter referred to as "program audio signal SPGM").
Is used to switch to the reproduced audio signal of the VTR to be reproduced next (hereinafter referred to as “preset audio signal SPST”). That is, at point P1,
The reproduced audio signal of the second VTR which is the program audio signal SPGM is switched to the reproduced audio signal of the third VTR which is the preset audio signal SPST by the audio mixer. At point P2, the preset audio signal SPST is changed from the reproduced audio signal of the third VTR which is the program audio signal SPGM.
Is switched to the reproduced audio signal of the first VTR. Similarly, at point P3, the reproduced audio signal of the first VTR is switched to the reproduced audio signal of the third VTR.

By the way, at these points P1, P2 and P3, not only signal cutout / cutin but also fadeout / fadein processing is performed.

Cut-out / cut-in means that the volume levels of the program audio signal SPGM and the preset audio signal SPST are set in advance as shown in FIG.
Upon switching signals, the volume level of the program audio signal SPGM is instantly set to zero level (silent state), and then switched to the preset audio signal SPST and output.

Further, the fade-out / fade-in means the program audio signal SPGM as shown in FIG.
And preset audio signal SPST have the same volume level in advance, and program audio signal S
By gradually attenuating the volume level of PGM and gradually increasing the preset audio signal SPST from a zero level to a prearranged volume level, the program audio signal SPGM to the preset audio signal SP
The signal is switched to ST. Here, the process of increasing the volume level of the preset audio signal SPST and continuously switching the signals before the volume level of the program audio signal SPGM becomes zero level is called a crossfade process. Controlling the attenuation and increase of time and volume level is DS
It is done by P3.

[0011]

By the way, in the above-described audio mixer, the crossfade process is repeated because the attenuation and increase of the crossfade time and the volume level are uniquely controlled by the DSP 3. However, the characteristics of attenuation and increase of crossfade time and volume level could not be changed arbitrarily.

Further, if the characteristics of the attenuation and increase of the crossfade time and the volume level can be freely changed manually, the same crossfade process cannot be easily repeated.

Therefore, the present invention provides an audio mixer that can perform crossfade processing that can freely change the characteristics of attenuation and increase of the crossfade time and volume level, and that can easily repeat the crossfade processing. is there.

[0014]

According to a first aspect of the present invention, there is provided an audio mixer which mixes first and second input audio signals to obtain an output audio signal and a signal mixing means. First and second signal level control means for controlling the levels of the first and second input audio signals, and first and second manually operated for varying the signal levels of the first and second input audio signals. A first operation means, a storage means for storing operation states of the first and second operation means as operation data, and a first operation based on the operation data read from the storage means.
And signal control means for controlling the signal levels of the first and second input audio signals by controlling the second signal level control means.

In the audio mixer according to the second aspect of the present invention, the signal level of one input audio signal is lowered by operating the first operating means, and the second operating means is operated to cross this. Then, the crossfade processing is performed by raising the signal level of the other input audio signal.

In the audio mixer according to the third aspect of the present invention, the storage means stores the operation data at a predetermined sampling cycle, and the storage means has the same cycle as the sampling cycle in which the operation data is stored in the storage means. The operation data is read out.

An audio mixer according to a fourth aspect of the present invention has a switch means for generating a start signal of the control operation of the signal control means.

[0018]

In the present invention, by manually operating the first and second operating means, for example, crossfade processing can be performed, and the manual operation of the first and second operating means is performed as predetermined sampling as operation data. It is stored in the storage means in a cycle. Therefore, the crossfade processing can be performed by freely changing the characteristics of attenuation and increase of the crossfade time and the volume level by the first and second operation means. Also, the first and second
Since the manual operation of the operating means is stored at a predetermined sampling cycle, by supplying a start signal from the switch means to the signal control means, the operation data stored in the storage means can be compared with the sampling cycle at the time of data storage. It is possible to read the data at the same cycle and repeatedly perform the above-mentioned free crossfade processing to easily implement it.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of an embodiment of an audio mixer according to the present invention will be described below with reference to FIG. In FIG. 1, parts corresponding to those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, 7 is a PGM fader. The PGM fader 7 is for manually changing the volume level of the program audio signal SPGM, and is composed of, for example, a variable resistor. This PGM
One terminal of the fader 7 is connected to the power supply terminal VCC and the other terminal is grounded, and the mover is connected to the A / D converter 9. An operation knob 7a is attached to the mover, and a position signal VPGM is supplied to the A / D converter 9 according to the operation position of the operation knob 7a.

Reference numeral 8 is a PST fader. This PST fader 8 is for manually changing the volume level of the preset audio signal SPST.
Like the fader 7, it is composed of a variable resistor. This PS
One terminal of the T fader 8 is connected to the power supply terminal Vcc, the other terminal is grounded, and the mover is connected to the A / D converter 9. An operation knob 8a is attached to the mover, and a position signal VPST is supplied to the A / D converter 9 according to the operation position of the operation knob 8a.

The PGM fader 7 and the PST fader 8 are not limited to the variable resistors, but may be those that magnetically or optically obtain the position signal. Further, it goes without saying that the A / D converter 9 is not necessary and the cost can be reduced if the position signal is obtained as digital data.

A microcomputer 11 (hereinafter referred to as "microcomputer") is connected to the A / D converter 9, and a memory 10 and a DSP 3 are connected to the microcomputer 11. Position signals VPGM and VPST indicating the operation position are
The operation data DPGM and DPST which are digital signals are converted by the A / D converter 9, stored in the memory 10 via the microcomputer 11, and simultaneously supplied to the DSP 3.

In the DSP3, the supplied operation data DPG
Signal processing is performed on the program audio signal SPGM and the preset audio signal SPST based on M and DPST. The audio output signal SOUT from the DSP 3 is output from the audio output terminal 4.

The conversion processing of the A / D converter 9, the data writing processing and the data reading processing of the memory 10, and the DSP 3
The signal processing is controlled by the microcomputer 11.

A switch unit 12 is connected to the microcomputer 11, and a start switch of the switch unit 12 is operated to supply a start signal ST for crossfade processing to the microcomputer 11. Although not shown in the figure, a control signal for starting the crossfade process may be supplied to the microcomputer 11 from an external device or the like.

Next, the operation of the crossfade processing will be described with reference to FIG. FIG. 2A shows a PGM fader 7 and a PST fader 8. The PGM fader 7 and the PST fader 8 are manually operated by the operation knobs 7a and 8a.
The volume level is controlled by sliding. 2A, the position of the operation knob 7a is the maximum position of the volume level, and the position of the operation knob 8a is the minimum position of the volume level. By sliding the operation knob 7a toward the minimum position, the volume level is attenuated and the fade-out operation is performed. In addition, the operation knob 8a
By sliding in the direction of the maximum position, the volume level is increased and the fade-in operation is performed.

FIG. 2B shows the operation knob 7 of the PGM fader 7.
FIG. 6 is a diagram showing changes in the sound of the program audio signal SPGM and the sound of the preset audio signal SPST when the operation knob 8a of the a and PST fader 8 is operated.
In FIG. 2B, the operation knob 7a of the PGM fader 7 is set to the maximum position and the operation knob 8a of the PST fader 8 is set to the minimum position until time t0, and only the sound of the program audio signal SPGM is output.

Here, when the operation knob 7a of the PGM fader 7 is operated toward the minimum position from the time point t0, the voltage of the position signal VPGM supplied to the A / D converter 9 decreases.
This position signal VPGM is converted by the A / D converter 9 into operation data DPGM at a predetermined sampling cycle. This operation data DPGM is stored in the memory 10 via the microcomputer 11.
Is stored in the memory and is supplied to the DSP 3 at the same time. Similarly,
When the operation knob 8a of the PST fader 8 is operated in the maximum position direction, the position signal VPST supplied to the A / D converter 9
Voltage rises, and this position signal VPST is transferred to the A / D converter 9
Is converted into operation data DPST at a predetermined sampling cycle. The operation data DPST is stored in the memory 10 via the microcomputer 11 and simultaneously supplied to the DSP 3.

In the DSP 3, the multiplication coefficient is determined by the supplied operation data. In other words, this multiplication coefficient is D
The output signal level is controlled by being multiplied by the signal input to SP3. For example, when the fader is operated in the maximum position direction, the multiplication coefficient becomes a large coefficient. Therefore, since the input audio signal is multiplied by a large coefficient, the signal level of the audio signal after multiplication is high. Similarly, when the fader is operated toward the minimum position, the multiplication coefficient is set to a small coefficient. Therefore, since the input audio signal is multiplied by a small coefficient, the signal level of the audio signal after multiplication is low.

That is, the operation knob 7a of the PGM fader 7
Is operated toward the minimum position, the signal level of the program audio signal SPGM output from the DSP 3 is reduced and the volume level is reduced. Also, PST
The operation knob 8a of the fader 8 is operated toward the maximum position to increase the signal level of the preset audio signal SPST output from the DSP 3 and increase the volume level.

After that, the operation knob 7a of the PGM fader 7
Is set to the minimum position and the operation knob 8a of the PST fader 8 is set to the maximum position until the time t1.
The operation data DPGM, DPST of the position signals VPGM, VPST converted by is recorded in the memory 10.

After the time t1, the operation knob 7a of the PGM fader 7 is set to the minimum position and the PST fader 8 is set.
Since the operation knob 8a of is set to the maximum position, only the sound of the preset audio signal SPST is output.

In this way, the manual operation from the time point t0 to the time point t1 until the output audio signal is switched from the program audio signal SPGM to the preset audio signal SPST is stored in the memory 10 as the operation data DPGM, DPST. The start and end of data storage in the memory 10 are controlled in relation to the position of the operation knob, for example. In other words, PGM fader 7
The data storage is started when the operation knob 7a is operated from the maximum position to the minimum position, or when the operation knob 8a of the PST fader 8 is operated from the minimum position to the maximum position. After that, PGM fader 7
When the operating knob 7a of is set to the minimum position, or PS
Data storage is stopped when the operation knob 8a of the T fader 8 is set to the maximum position. Note that the data storage may be stopped after a predetermined time has elapsed from the start of the data storage so that the storage capacity of the memory 10 is not exceeded, and the elapsed time from the determination based on the position of the operation knob and the start of the data storage. It goes without saying that the determinations according to (4) may be combined.

The data stored in the memory 10 is supplied with the start signal ST from the switch unit 12 to the microcomputer 11, so that the data is stored at the same cycle as the sampling cycle when the operation data DPGM and DPST are stored in the memory 10. It is read by the microcomputer 11 and supplied to the DSP 3. Therefore, the manual fader operation from the time point t0 to the time point t1 is reproduced, and the program audio signal S
Crossfader processing from PGM to preset audio signal SPST is performed.

As described above, according to this embodiment, the operation knob 7a of the PGM fader 7 and the operation knob 8 of the PST fader 8 are used.
By manually operating a, the crossfade process can be performed by freely controlling the characteristics of the time and signal level attenuation or increase of the crossfader. Further, since this manual operation is stored in the memory 10 at a predetermined sampling cycle, the same crossfade processing as the manual operation is repeated by appropriately reading the data stored in the memory 10 at the same cycle as the sampling cycle of data storage. It can be carried out.

If a plurality of manual operation patterns are stored in the memory 10 and the plurality of manual operation patterns are selected by the switch unit 12 to execute the processing, different processing can be easily performed. It can be carried out.

Further, not only the manual operation pattern stored in the memory 10 but also the data stored in the memory 10 is read at a cycle different from the sampling cycle at the time of data storage, so that the stored fade time of the manual operation is stored. Can be changed, so that more processing can be easily performed.

[0039]

According to the present invention, by manually operating the first and second operating means, for example, crossfade processing can be performed, and the manual operation of the first and second operating means is used as operation data. It is stored in the storage means at a predetermined sampling period. Therefore, the first
Also, the crossfade processing can be performed by freely changing the characteristics of the attenuation and increase of the crossfade time and the volume level by the second operation means. Also, the first and second
Since the manual operation of the operating means is stored at a predetermined sampling cycle, by supplying a start signal from the switch means to the signal control means, the operation data stored in the storage means can be compared with the sampling cycle at the time of data storage. It is possible to read out at the same cycle and repeatedly perform the above-described free crossfade processing easily.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of an audio mixer according to the present invention.

FIG. 2 is a diagram showing an operation of the audio mixer according to the present invention.

FIG. 3 is a diagram showing a configuration of a conventional audio mixer.

FIG. 4 is a diagram showing AB roll editing.

FIG. 5 is a diagram showing a cutout / cutin operation.

FIG. 6 is a diagram showing a fade-out / fade-in operation.

[Explanation of symbols]

 3 Digital Signal Processor (DSP) 7 PGM Fader 7a, 8a Operation Knob 8 PST Fader 9 A / D Converter 10 Memory 11 Microcomputer 12 Switch Section

Claims (4)

[Claims] 1. A signal mixing means for mixing first and second input audio signals to obtain an output audio signal, and controlling levels of the first and second input audio signals mixed by the signal mixing means. First and second signal level control means, first and second operation means that are manually operated to change the signal levels of the first and second input audio signals, and the first and second Storage means for storing the operation state of the operation means as operation data, and the first and second input by controlling the first and second signal level control means based on the operation data read from the storage means. An audio mixer comprising signal control means for controlling a signal level of an audio signal. 2. While lowering the signal level of one input audio signal by operating the first operating means, by operating the second operating means, the signal level of the other input audio signal is crossed with the other input audio signal. The audio mixer according to claim 1, wherein crossfade processing is performed by increasing a signal level. 3. The operation data is stored in the storage means at a predetermined sampling cycle, and the operation data is read from the storage means at the same cycle as the sampling cycle in which the operation data is stored in the storage means. The audio mixer according to claim 1 or 2. 4. The audio mixer according to claim 1, further comprising switch means for generating a start signal of a control operation of the signal control means.