CN112995591A - External pickup system and pickup method of camera - Google Patents
External pickup system and pickup method of camera Download PDFInfo
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- CN112995591A CN112995591A CN202110149176.3A CN202110149176A CN112995591A CN 112995591 A CN112995591 A CN 112995591A CN 202110149176 A CN202110149176 A CN 202110149176A CN 112995591 A CN112995591 A CN 112995591A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/18—Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R1/00—Details of transducers, loudspeakers or microphones
- H04R1/08—Mouthpieces; Microphones; Attachments therefor
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R3/00—Circuits for transducers, loudspeakers or microphones
Abstract
The invention relates to an external sound pick-up system and a sound pick-up method of a camera, wherein the external sound pick-up system of the camera comprises a single sound source circuit and a second level adjusting circuit which is used for connecting an audio acquisition device of the camera; the single-tone source circuit is connected with the second level adjusting circuit through a transmission line, and is used for collecting and amplifying original audio signals to obtain amplified audio signals and sending the amplified audio signals to the second level adjusting circuit; the second level adjusting circuit is used for compressing and amplifying the audio signal to obtain an audio signal and sending the audio signal to an audio acquisition device of the camera. The single-tone source circuit is used for collecting and amplifying the audio signals, and the second level adjusting circuit is used for compressing the amplified audio signals, so that the problems that the video camera and the audio collecting device of the video camera are far away from people and the collecting scene is too large, and the sound collection and recording are unclear are solved.
Description
Technical Field
The invention relates to the technical field of pickup, in particular to an external pickup system of a camera and a pickup method.
Background
At present, a monitoring system is one of the most applied systems in a security system, and video monitoring is the mainstream in the market at present, wherein a panoramic camera is an important component of video monitoring. The panoramic camera is a camera capable of independently realizing monitoring without dead angles in a large range, the monitoring effect of 360 degrees and 180 degrees can be respectively achieved when the mainstream panoramic camera is hoisted and mounted on the wall, the monitoring appeal of a client to a wider area can be achieved, and the panoramic camera is widely applied to enable sampling and recording of panoramic image information to be possible.
However, the panoramic camera is installed at a higher position, so that a sound pick-up carried by the camera is far away from people, and thus, sound collection and recording are unclear; in addition, the scene of panoramic camera video acquisition is great, makes the various sound in the scene mix together easily, and is not heard clearly.
Disclosure of Invention
The invention provides an external sound pickup system and a sound pickup method of a video camera, aiming at solving the problems that the existing video camera is far away from people and the collection scene is too large, so that the sound collection and recording are unclear.
In a first aspect, to solve the above technical problem, the present invention provides an external microphone system of a camera, which includes a single-tone source circuit and a second level adjustment circuit for connecting to an audio acquisition device of the camera;
the single sound source circuit is used for originally acquiring and amplifying an audio signal to obtain an amplified audio signal, and sending the amplified audio signal to the second level adjusting circuit;
the second level adjusting circuit is used for compressing the amplified audio signal to obtain an audio signal and sending the audio signal to an audio acquisition device of the camera.
The external adapter system provided by the invention has the beneficial effects that: the problem that the camera and the audio acquisition device of the camera are far away from people and the acquisition scene is too large, so that sound acquisition and recording are unclear is solved, the single-tone source circuit is used for acquiring and amplifying audio signals, the second level adjustment circuit is used for compressing the amplified audio signals, the original audio signals are firstly amplified and then compressed to obtain final audio signals, the effect of reducing noise of the audio signals can be achieved, and therefore the sound received by the camera is clearer.
On the basis of the technical scheme, the external sound pick-up system can be further improved as follows.
Furthermore, the external sound pickup system also comprises a control platform, an analog electronic switch, a camera communication module used for communicating with the control platform and a counter used for connecting the camera communication module, at least two single sound source circuits are provided,
the counter is also connected with an address terminal of an analog electronic switch, a common input/output terminal of the analog electronic switch is connected with the second level adjustment circuit, a plurality of input/output terminals of the analog electronic switch are respectively connected with each single-tone source circuit,
the counter is used for generating a gating address of each single-tone source circuit;
the control platform is used for selecting one of the at least two single sound source circuits to be connected according to user requirements, generating a first signal and sending the first signal to the camera communication module;
the camera communication module is used for receiving and processing the first signal to obtain a gating pulse signal and sending the gating pulse signal to the counter;
the counter is also used for processing the gating pulse signal to obtain a first address and sending the first address to the analog electronic switch;
the analog electronic switch is used for processing the first address and selecting a corresponding single-tone source circuit to be switched on according to the processed first address.
The beneficial effect of adopting the further scheme is that: the single-tone source circuits are at least two and can be arranged at different positions to receive multi-channel audio signals, so that the situation that sound collection and recording are unclear and collected sound is unclear due to the fact that a pickup carried by the camera is far away from people due to the fact that the installation position of the camera is high can be avoided; in addition, through control platform, camera communication module, analog switch and counter, can realize that the user realizes selecting one of many single source circuits to put through according to its demand through operation control platform to it is great to avoid the scene of panorama camera video acquisition, makes the various sound in the scene mix together easily, leads to gathering the unclear condition of sound.
Further, the single sound source circuit and the second level adjusting circuit are connected through the transmission line;
the transmission line is used for transmitting the amplified audio signal to the second level adjustment circuit.
The beneficial effect of adopting the further scheme is that: when traditional adapter returns audio signal, in order to avoid receiving too much interference in transmission process, need adopt the shielded wire to transmit, because single sound source circuit and second level adjustment circuit carried out amplification recompression to the original audio signal who gathers earlier, so the interference that receives in transmission process is compressed back by second level adjustment circuit, can not audio signal cause serious influence, lead to sound unclear etc. so can adopt ordinary transmission line to transmit the amplified audio signal that single sound source circuit obtained to second level adjustment circuit, thereby make this adapter system can adapt to more scenes, have universal applicability.
Furthermore, the single sound source circuit comprises a microphone, a microphone automatic gain amplifier, a preceding stage amplifying circuit, a frequency selecting circuit and a first level adjusting circuit,
the output end of the microphone is connected with the input end of the microphone automatic gain amplifier, the output end of the microphone automatic gain amplifier is connected with the input end of the pre-stage amplifying circuit, the output end of the pre-stage amplifying circuit is connected with the input end of the frequency selecting circuit, the output end of the frequency selecting circuit is connected with the input end of the first level adjusting circuit, and the output end of the first level adjusting circuit is connected with the transmission line;
the microphone is used for collecting an original audio signal and sending the original audio signal to the microphone automatic gain amplifier;
the microphone automatic gain amplifier is used for processing the original audio signal to obtain a first amplified audio signal and sending the first amplified audio signal to the preceding stage amplifying circuit;
the preceding stage amplifying circuit is used for amplifying the first amplified audio signal to obtain a second amplified audio signal and sending the second amplified audio signal to the frequency selecting circuit;
the frequency selection circuit is used for selecting the second amplified audio signal to obtain a third amplified audio signal and sending the third amplified audio signal to the first level adjustment circuit;
the first level adjusting circuit is used for processing the third amplified audio signal to obtain an amplified audio signal and transmitting the amplified audio signal to the second level adjusting circuit by using the transmission line.
The beneficial effect of adopting the further scheme is that: the microphone can collect original audio signals, and the microphone automatic gain amplifier can adjust different signal gains according to the length of a signal line of the field sound pickup and the difference of field electromagnetic environments, so that the subsequent received sound effect is better; the pre-stage amplifying circuit can further amplify the first audio signal, so that the signal can be conveniently compressed subsequently to realize noise reduction; the frequency selection circuit only passes through the frequency band of voice by selecting frequency of the signal, so that the interference in the signal is reduced; the first level adjusting circuit can amplify the third amplified audio signal again, so that the levels of the plurality of single sound source circuits are adjusted to be balanced and consistent.
Further, the noise-reducing circuit also comprises a filter circuit used for filtering noise, and the filter circuit is connected with the second level adjusting circuit in parallel.
By connecting the filter circuit to the second level adjustment circuit, some noise waves generated on the line can be filtered, interference is reduced, and therefore the audio signal is clearer.
Furthermore, each single sound source circuit adopts a switch power supply or a linear power supply to supply power.
The single-tone source circuit adopts a switching power supply or a linear power supply to supply power, so that current noise can be reduced, and interference can be reduced.
In a second aspect, the present invention provides an external pickup method for a camera, which employs the external pickup system for a camera according to the above-mentioned scheme, and includes the following steps:
the single-tone source circuit collects and amplifies audio signals to obtain amplified audio signals, and sends the amplified audio signals to the second level adjusting circuit;
and the second level adjusting circuit compresses the amplified audio signal to obtain an audio signal of an audio acquisition device for sending to the camera.
The method for externally connecting the pickup has the advantages that: the problem that the camera and the audio acquisition device of the camera are far away from people and the acquisition scene is too large, so that sound acquisition and recording are unclear is solved, the single-tone source circuit is used for acquiring and amplifying audio signals, the second level adjustment circuit is used for compressing the amplified audio signals, the original audio signals are firstly amplified and then compressed to obtain final audio signals, the effect of reducing noise of the audio signals can be achieved, and therefore the sound received by the camera is clearer.
On the basis of the technical scheme, the method for externally connecting the pickup with the camera can be further improved as follows.
Furthermore, the external sound pickup system also comprises a control platform, an analog electronic switch, a camera communication module used for communicating with the control platform, a counter used for connecting the camera communication module, and at least two single-tone source circuits,
the counter generates a strobe address of each of the single-tone source circuits;
the control platform selects one of the at least two single sound source circuits to be connected according to user requirements, generates a first signal and sends the first signal to the camera communication module;
the camera communication module processes the first signal to obtain a gating pulse signal;
the counter processes the gating pulse signal to obtain a first address, and sends the first address to the analog electronic switch;
and the analog electronic switch processes the first address and selects a corresponding single-tone source circuit to be switched on according to the processed first address.
The beneficial effect of adopting the further scheme is that: the single-tone source circuits are at least two and can be arranged at different positions to receive multi-channel audio signals, so that the situation that sound collection and recording are unclear and collected sound is unclear due to the fact that a pickup carried by the camera is far away from people due to the fact that the installation position of the camera is high can be avoided; in addition, through control platform, camera communication module, analog switch and counter, can realize that the user realizes selecting one of many single source circuits to put through according to its demand through operation control platform to it is great to avoid the scene of panorama camera video acquisition, makes the various sound in the scene mix together easily, leads to gathering the unclear condition of sound.
Further, the external adapter system further comprises a transmission line, and the transmission line transmits the amplified audio signal to the second level adjustment circuit.
The beneficial effect of adopting the further scheme is that: when traditional adapter returns audio signal, in order to avoid receiving too much interference in transmission process, need adopt the shielded wire to transmit, because single sound source circuit and second level adjustment circuit carried out amplification recompression to the original audio signal who gathers earlier, so the interference that receives in transmission process is compressed back by second level adjustment circuit, can not audio signal cause serious influence, lead to sound unclear etc. so can adopt ordinary transmission line to transmit the amplified audio signal that single sound source circuit obtained to second level adjustment circuit, thereby make this adapter system can adapt to more scenes, have universal applicability. .
Furthermore, the single sound source circuit comprises a microphone, a microphone automatic gain amplifier, a preceding stage amplifying circuit, a frequency selecting circuit and a first level adjusting circuit,
the microphone collects audio signals and sends the audio signals to the microphone automatic gain amplifier;
the microphone automatic gain amplifier processes the audio signal to obtain a first amplified audio signal and sends the first amplified audio signal to the preceding stage amplifying circuit;
the preceding stage amplifying circuit amplifies the first amplified audio signal to obtain a second amplified audio signal and sends the second amplified audio signal to the frequency selecting circuit;
the frequency selection circuit selects the second amplified audio signal to obtain a third amplified audio signal and sends the third amplified audio signal to the level adjustment circuit;
and the level adjusting circuit processes the third amplified audio signal to obtain an amplified audio signal and transmits the amplified audio signal to the second level adjusting circuit by using the transmission line.
The beneficial effect of adopting the further scheme is that: the microphone can collect original audio signals, and the microphone automatic gain amplifier can adjust different signal gains according to the length of a signal line of the field sound pickup and the difference of field electromagnetic environments, so that the subsequent received sound effect is better; the pre-stage amplifying circuit can further amplify the first audio signal, so that the signal can be conveniently compressed subsequently to realize noise reduction; the frequency selection circuit only passes through the frequency band of voice by selecting frequency of the signal, so that the interference in the signal is reduced; the first level adjusting circuit can amplify the third amplified audio signal again, so that the levels of the plurality of single sound source circuits are adjusted to be balanced and consistent.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention is further described below with reference to the accompanying drawings and embodiments.
Fig. 1 is a block diagram of an external pickup system of a video camera according to an embodiment of the present invention;
fig. 2 is a circuit diagram of a microphone amplification booster according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of an equivalent circuit of an audio signal processing process according to an embodiment of the present invention;
FIG. 4 is a circuit diagram of single-tone source circuit gating according to an embodiment of the present invention;
fig. 5 is a flowchart illustrating a method for externally connecting a pickup to a camera according to an embodiment of the present invention.
Detailed Description
The following examples are further illustrative and supplementary to the present invention and do not limit the present invention in any way.
Example one
An external microphone system of a camera according to an embodiment of the present invention will be described below with reference to the accompanying drawings.
As shown in fig. 1, an external microphone system of a camera according to an embodiment of the present invention includes a single sound source circuit 100, a second level adjustment circuit 201 for connecting to an audio acquisition device 205 of the camera, and a transmission line 300;
the single-tone source circuit 100 is configured to originally acquire and amplify an audio signal to obtain an amplified audio signal, and send the amplified audio signal to the second level adjustment circuit 201;
the second level adjustment circuit 201 is configured to compress the amplified audio signal to obtain an audio signal, and send the audio signal to an audio acquisition device 205 of the camera;
as shown in fig. 1, the single tone source circuit 100 and the second level adjustment circuit 201 are connected by a transmission line 300, the transmission line 300 is indicated by a black bold straight line, and the transmission line 300 transmits the amplified audio signal to the second level adjustment circuit 201.
The single-tone source circuit 100 is used for collecting and amplifying audio signals, the second level adjusting circuit 201 is used for compressing the amplified audio signals, the original audio signals are firstly amplified and then compressed to obtain final audio signals, the effect of reducing noise of the audio signals can be achieved, and therefore the sound received by the camera is clearer.
The single-tone source circuits 100 are at least two and can be installed at different positions to receive multi-channel audio signals, so that the situation that sound collection and recording are unclear due to the fact that the installation position of the camera is high and a sound pick-up of the camera is far away from people can be avoided.
In addition, when the traditional sound pick-up returns an audio signal, in order to avoid excessive interference in the transmission process, a shielded wire is needed for transmission, and since the single-tone source circuit 100 and the second level adjustment circuit 201 amplify and compress the acquired original audio signal first, after the interference in the transmission process is compressed by the second level adjustment circuit 201, the audio signal cannot be seriously affected, and the sound is unclear, and the like, the amplified audio signal obtained by the single-tone source circuit 100 can be transmitted to the second level adjustment circuit 201 by using the common transmission line 300, so that the sound pick-up system can adapt to more scenes and has general applicability.
Preferably, the single-tone source circuit 100 includes a microphone 101, a microphone automatic gain amplifier 102, a pre-amplifier circuit 103, a frequency-selecting circuit 104 and a first level adjustment circuit 105,
the output end of the microphone 101 is connected with the input end of the microphone automatic gain amplifier 102, the output end of the microphone automatic gain amplifier 102 is connected with the input end of the pre-stage amplifying circuit 103, the output end of the pre-stage amplifying circuit 103 is connected with the input end of the frequency selecting circuit 104, the output end of the frequency selecting circuit 104 is connected with the input end of the first level adjusting circuit 105, and the output end of the first level adjusting circuit 105 is connected with the transmission line 300;
the microphone 101 is used for collecting an original audio signal and sending the original audio signal to the microphone automatic gain amplifier 102;
the microphone automatic gain amplifier 102 is configured to process an original audio signal to obtain a first amplified audio signal and send the first amplified audio signal to the pre-stage amplifying circuit 103;
the pre-stage amplifying circuit 103 is configured to amplify the first amplified audio signal to obtain a second amplified audio signal, and send the second amplified audio signal to the frequency selecting circuit 104;
the frequency selection circuit 104 is configured to select the second amplified audio signal to obtain a third amplified audio signal, and send the third amplified audio signal to the first level adjustment circuit 105;
the first level adjustment circuit 105 is configured to process the third amplified audio signal to obtain an amplified audio signal, and transmit the amplified audio signal to the second level adjustment circuit 201 through the transmission line 300.
Specifically, the microphone AGC amplifier 102 is a MAX9814 microphone AGC amplifier, which is a low cost, high quality microphone amplifier, with built-in Automatic Gain Control (AGC) and low noise microphone bias, and integrates a low noise preamplifier, a Variable Gain Amplifier (VGA), an output amplifier, a microphone bias generator, and an AGC control circuit.
The circuit connection of the MAX9814 microphone AGC amplifier is shown in figure 2, a resistor R1 and a resistor R2 form an AGC threshold circuit, an A/R pin is used for selecting the three-state starting and releasing proportion of the AGC circuit, the starting and releasing time ratio of the AGC circuit is controlled, a CT pin is connected with a timing capacitor, the AGC control and releasing time is controlled, and the automatic gain of the AGC circuit from 0dB to 20dB is completed. The GAIN pin is a GAIN control pin of the amplifier, and the GAIN control of the three-state amplifier is as follows:
the signal output GAIN is 40dB when GAIN is equal to VDD;
the GAIN is GND, and the signal output GAIN is 50 dB;
thirdly, the GAIN is suspended, and the signal output GAIN is 60 dB;
in addition, the CG pin is connected with a 0.22uF capacitor to the ground, the output amplifier is subjected to direct current offset adjustment, zero offset of an output end is ensured, and the capacitor and the resistor which are respectively connected with BIAS and MIBIAS are BIAS circuits of the amplifier.
After the microphone 101 collects an original audio signal and the microphone automatic gain amplifier 102 amplifies a gain to obtain a first amplified audio signal, a circuit diagram as shown in fig. 3 is accessed:
1) the first amplified audio signal enters the pre-stage amplification circuit 103: as shown in fig. 3, the pre-amplifier circuit 103 includes an operational amplifier Y1, a switch K, and resistors R12, R13, R5, R6, and R7. Wherein, R5, R6 and R7 are connected in parallel, and the connecting end is connected with the non-inverting input end of the operational amplifier Y1; the switch K is connected to any one of the circuits R5, R6, and R7, and the amplification factors of the pre-stage amplification circuit 103 are different.
As shown in fig. 3, the resistors R12 and R13 are both 1K, the resistor R5 is 10K, the resistor R6 is 100K, the resistor R7 is 300K, and the amplification factor formula is:
V2＝V1*Rm/R13 m∈[5，7]
wherein, V2The first amplified audio signal is amplified by the pre-amplifier circuit 103 to obtain the output voltage V of the second amplified audio signal1An input voltage at which the first amplified audio signal is input to the pre-stage amplification circuit 103. When m is 5, V2＝V 110, i.e. 10 times larger; when m is 6, V2＝V 1100, i.e., 100 times larger; when m is 7, V2＝V 1300, i.e. 300 times larger;
suppose that an input voltage V of the first amplified audio signal is input1Is 100V, and m is 5, the output voltage V of the second amplified audio signal is2Is 1000V.
2) The second amplified audio signal enters the frequency selection circuit 104: as shown in fig. 3, the capacitors C11, C12 and the resistor R14 form an RC frequency-selecting circuit, the capacitor C11 and the resistor R14 are connected to filter out dc current, and the capacitor C12 filters out the frequency band of the voice signal, which is about 300Hz-3400Hz, so as to obtain a third amplified audio signal.
Since the voltage of the frequency selecting circuit 104 does not change, the output voltage V of the third amplified audio signal3＝V2And thus the output voltage V of the second amplified audio signal2At 1000V, V3Also 1000V.
3) The third amplified audio signal enters the first level adjustment circuit 105: as shown in fig. 3, the first level adjustment circuit 105 includes an operational amplifier Y2, a sliding resistor W1, a capacitor C13, and resistors R8 and R9.
In fig. 3, the sliding resistance W1 ranges from 0K to 200K, and the resistance R9 ranges from 10K; therefore, as can be seen from the amplification factor formula in 1), the amplification factor of the first level adjustment circuit 105 can be varied between 1 and 20 times by adjusting the sliding resistance W1.
Suppose, thirdOutput voltage V of amplified audio signal31000V, and the sliding resistance W1 is 20K, the output voltage V of the amplified audio signal4Is 2000V.
It can be seen that the output voltage of the amplified audio signal output by the first level adjustment circuit 105 can be flexibly changed. In order to facilitate the subsequent second level adjustment circuit 201 to perform unified compression and amplification on the audio signals, the amplification factor of the first level adjustment circuit 105 may be adjusted artificially so that the output voltages of the amplified audio signals output by the plurality of single-tone source circuits 100 are balanced and consistent.
4) The amplified audio signal is transmitted through the transmission line 300: as shown in fig. 3, the amplified audio signal is transmitted through a transmission line 300, wherein the transmission line 300 may use a shielded wire or a normal signal line, and as shown in fig. 3, the length of the signal line L is about 30 meters, and the signal line is also subjected to an interference voltage U during transmission.
Suppose that the output voltage V of the audio signal is amplified42000V, the interference voltage U is 2V, and the input voltage V of the second level adjustment circuit 201 is then5Is 2002V.
5) The amplified audio signal enters the second level adjustment circuit 201: as shown in fig. 3, the second level adjustment circuit 201 includes a sliding resistor W2, resistors R10, R11, and the compression factor formula is:
V6＝V5*R11/(R10+W2)
wherein, the value range of the sliding resistance W2 is 0-100K, the resistance R10 and R11 are 2K and 5.1K respectively, and V is5Is the input voltage, V, of the second level adjustment circuit 2016The output voltage of the second level adjustment circuit 201 is also the voltage of the audio signal.
Suppose that the input voltage V of the second level adjustment circuit 2015The voltage is 2002V, 2V is interference voltage U, the sliding resistance W2 is 100K, and V can be obtained after calculation of a compression multiple formula6Is 100.1V, wherein 100V is the voltage of the audio signal and 0.1V is the interference voltage, therefore, the collected original audio signal is continuously amplifiedAnd then, the audio signal is transmitted, an interference signal is received in the transmission process, finally, the amplified original audio signal and the interference signal are compressed together, at the moment, the amplified original audio signal returns to the normal range, and the interference signal is reduced, so that the influence of the interference signal on the audio signal is reduced.
Therefore, the microphone 101 can collect the original audio signal, and the microphone automatic gain amplifier 102 can adjust different signal gains according to the length of the signal line of the field sound pickup and the difference of the field electromagnetic environment, so that the subsequent received sound effect is better; the pre-stage amplifying circuit 103 can further amplify the first audio signal, so that the signal can be conveniently compressed subsequently to realize noise reduction; the frequency selection circuit 104 reduces interference in the signal by selecting the frequency of the signal so that only the frequency band of the voice is passed; the first level adjustment circuit 105 amplifies the third amplified audio signal again, so as to adjust the levels of the plurality of single-tone source circuits 100 to be balanced.
Preferably, the single tone source circuit further comprises a control platform 400, an analog electronic switch 204, a camera communication module 202 for communicating with the control platform 400, and a counter 203 for connecting the camera communication module 202, at least two of the single tone source circuits 100,
the counter 203 is further connected to an address terminal of an analog electronic switch 204, a common input/output terminal of the analog electronic switch 204 is connected to the second level adjustment circuit 201, a plurality of input/output terminals of the analog electronic switch 204 are respectively connected to each of the single-tone source circuits 100,
the counter 203 is used for generating a gating address of each single-tone source circuit 100;
the control platform 400 is configured to select one of the at least two single-tone source circuits 100 to be turned on according to a user requirement, generate a first signal, and send the first signal to the camera communication module 202;
the camera communication module 202 is configured to receive and process the first signal, obtain a strobe signal, and send the strobe signal to the counter 203;
the counter 203 is further configured to process the strobe signal to obtain a first address and send the first address to the analog electronic switch 204;
the analog electronic switch 204 is used for processing the first address and selecting the corresponding single-tone source circuit 100 to be switched on according to the processed first address.
Specifically, the control platform 400 is an operation interface, and an operator can select the single-tone source circuit 100 to be turned on the control platform 400, at this time, the control platform 400 sends a first signal to the camera communication module 202, and the camera communication module 202 receives and analyzes the first signal to obtain a strobe signal, where the strobe signal is a digital signal.
Specifically, assuming that there are 8 single-tone source circuits 100, as shown in fig. 4, the counter 203 is a CD4024BCM chip, the analog electronic switch 204 is a CD4051BC chip, the strobe signal is input from the CLK pin of the CD4024BCM chip, the Q1, Q2, and Q3 pins of the CD4024BCM chip are connected to the a, B, and C pins of the address terminal of the CD4051BC chip, the X0-X7 pins, i.e., the input/output terminals of the CD4051BC chip are respectively connected to the 8-channel single-tone source circuit 100, and the X pin, i.e., the common input/output terminal of the CD4051BC chip is connected to the second level adjustment circuit 201.
1) The CD4024BCM chip generates a strobe address for each of the single-tone source circuits 100: the original Q1, Q2 and Q3 of the CD4024BCM chip are 000. The number of pulses after the strobe signal is input is recorded as Q1, Q2 and Q3 of the CD4024BCM chip;
the strobe addresses for the 8 single-tone source circuits 100 may be in order as follows:
the 2 nd single-tone source circuit 100: the strobe addresses Q1, Q2, Q3 are 010;
item 3 single-tone source circuit 100: the strobe addresses Q1, Q2, Q3 are 011;
the 4 th single-tone source circuit 100: the strobe addresses Q1, Q2, Q3 are 100;
the 5 th single-tone source circuit 100: the strobe addresses Q1, Q2, Q3 are 101;
the 6 th single-tone source circuit 100: the strobe addresses Q1, Q2, Q3 are 110;
the 7 th single-tone source circuit 100: the strobe addresses Q1, Q2, Q3 are 111;
the 8 th single-tone source circuit 100: the strobe addresses Q1, Q2, Q3 are 000;
the Q1, Q2 and Q3 of the CD4024BCM chip restart counting from 000, so that the generation work of 8 MIC gating addresses from 000 to 111 is completed, and the generation of 8 remote MIC addresses is realized.
2) The CD4024BCM chip receives the gating pulse signal and processes the gating pulse signal to obtain a first address; and outputs the first address to the CD4051BC chip through pins Q1, Q2, and Q3, assuming that the first addresses Q1, Q2, and Q3 are 011.
3) The address terminals a, B and C of the CD4051BC chip receive and decode the first address, and then select one of the X0-X7 pins of the CD4051BC chip to turn on according to the decoded first address, at which time 1 single tone source circuit 100 can be selected from the 8-way single tone source circuit 100 to turn on.
According to 2), since the first addresses Q1, Q2 and Q3 are 011, the X2 pin is selected to turn on, that is, the 3 rd tone source circuit 100 in the 8 tone source circuits 100 is selected to turn on after the CD4051BC chip decodes the first address.
Through the control platform 400, the camera communication module 202, the analog switch and the counter 203, a user can select one of the multiple single-tone source circuits 100 to be switched on according to the requirement of the user through operating the control platform 400, so that the situation that the collected sound is unclear due to the fact that a scene of video collection of the panoramic camera is large and various sounds in the scene are easily mixed together is avoided.
Preferably, a filter circuit for filtering noise is further included, and the filter circuit is connected in parallel with the second level adjustment circuit 201.
By connecting the filter circuit to the second level adjustment circuit 201, some noise generated on the line can be filtered out, and interference can be reduced, so that the audio signal can be clearer.
Preferably, each of the single-tone source circuits 100 is powered by a switching power supply or a linear power supply.
The single-tone source circuit 100 can reduce current noise and interference by adopting a switching power supply or a linear power supply for power supply.
Example two
The following describes an external pickup method of a camera according to an embodiment of the present invention with reference to the drawings.
As shown in fig. 5, with the external sound pickup system of the camera according to the first embodiment, an external sound pickup method of a camera includes the following steps:
s1, the single-tone source circuit 100 collects and amplifies an audio signal to obtain an amplified audio signal, and sends the amplified audio signal to the second level adjustment circuit 201;
s2, the second level adjustment circuit 201 compresses the amplified audio signal to obtain an audio signal for sending to the audio capture device 205 of the camera.
The single-tone source circuit 100 is used for collecting and amplifying audio signals, the second level adjusting circuit 201 is used for compressing the amplified audio signals, the original audio signals are firstly amplified and then compressed to obtain final audio signals, the effect of reducing noise of the audio signals can be achieved, and therefore the sound received by the camera is clearer.
The single-tone source circuits 100 are at least two and can be installed at different positions to receive multi-channel audio signals, so that the situation that the collected sound is unclear and the situation that the collected sound is unclear due to the fact that the sound pick-up of the camera is far away from people can be avoided.
Preferably, the external microphone system further includes a control platform 400, an analog electronic switch 204, a camera communication module 202 for communicating with the control platform 400, and a counter 203 for connecting the camera communication module 202, and selecting one of the at least two single-tone source circuits 100 to be turned on by the control platform 400 specifically includes:
s01, the counter 203 generates a strobe address of each of the single-tone source circuits 100;
s02, the control platform 400 selects one of the at least two single-tone source circuits 100 to be turned on according to the user' S requirement, generates a first signal and sends the first signal to the camera communication module 202;
s03, the camera communication module 202 processes the first signal to obtain a strobe signal;
s04, the counter 203 processes the strobe signal to obtain a first address, and sends the first address to the analog electronic switch 204;
and S05, processing the first address by the analog electronic switch 204, and selecting the corresponding single-tone source circuit 100 to be switched on according to the processed first address.
Through the control platform 400, the camera communication module 202, the analog switch and the counter 203, a user can select one of the multiple single-tone source circuits 100 to be switched on according to the requirement of the user through operating the control platform 400, so that the situation that the collected sound is unclear due to the fact that a scene of video collection of the panoramic camera is large and various sounds in the scene are easily mixed together is avoided.
Preferably, S1 specifically includes:
s11, collecting an audio signal by a microphone 101 and sending the audio signal to an automatic gain amplifier 102 of the microphone;
s12, the microphone automatic gain amplifier 102 processes the audio signal to obtain a first amplified audio signal, and sends the first amplified audio signal to the pre-stage amplifying circuit 103;
s13, the pre-stage amplifying circuit 103 amplifies the first amplified audio signal to obtain a second amplified audio signal, and sends the second amplified audio signal to the frequency selecting circuit 104;
s14, the frequency selecting circuit 104 selects the second amplified audio signal to obtain a third amplified audio signal and sends the third amplified audio signal to the level adjusting circuit;
s15, the level adjustment circuit processes the third amplified audio signal to obtain an amplified audio signal, and the amplified audio signal is transmitted to the second level adjustment circuit 201 through the transmission line 300.
The microphone 101 can collect original audio signals, and the microphone automatic gain amplifier 102 can adjust different signal gains according to the length of a signal line of a field sound pickup and the difference of field electromagnetic environments, so that the subsequent received sound effect is better; the pre-stage amplifying circuit 103 can further amplify the first audio signal, so that the signal can be conveniently compressed subsequently to realize noise reduction; the frequency selection circuit 104 reduces interference in the signal by selecting the frequency of the signal so that only the frequency band of the voice is passed; the first level adjustment circuit 105 amplifies the third amplified audio signal again, so as to adjust the levels of the plurality of single-tone source circuits 100 to be balanced.
In the above embodiments, although the steps are numbered as S1, S2, etc., but only the specific embodiments are given in this application, a person skilled in the art may adjust the execution sequence of S1, S2, etc. according to the actual situation, and this is within the scope of the present invention, and it is understood that some embodiments may include some or all of the above embodiments.
In the above embodiments of the method for externally connecting a pickup to a camera according to the present invention, reference may be made to the above steps for implementing corresponding functions of the parameters and the unit modules in the externally connected pickup system of the camera, which are not described herein again.
As will be appreciated by one skilled in the art, the present invention may be embodied as a system, method or computer program product. Accordingly, the present disclosure may be embodied in the form of: may be embodied entirely in hardware, entirely in software (including firmware, resident software, micro-code, etc.) or in a combination of hardware and software, and may be referred to herein generally as a "circuit," module "or" system. Furthermore, in some embodiments, the invention may also be embodied in the form of a computer program product in one or more computer-readable media having computer-readable program code embodied in the medium.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (10)
1. An external adapter system of a camera is characterized by comprising a single-tone source circuit and a second level adjusting circuit which is connected with an audio acquisition device of the camera;
the single sound source circuit is used for collecting and amplifying an original audio signal to obtain an amplified audio signal, and sending the amplified audio signal to the second level adjusting circuit;
the second level adjusting circuit is used for compressing the amplified audio signal to obtain an audio signal and sending the audio signal to an audio acquisition device of the camera.
2. The microphone system of claim 1 further comprising a control platform, an analog electronic switch, a camera communication module for communicating with the control platform, and a counter for connecting the camera communication module, the single tone source circuit having at least two,
the counter is also connected with an address terminal of an analog electronic switch, a common input/output terminal of the analog electronic switch is connected with the second level adjustment circuit, a plurality of input/output terminals of the analog electronic switch are respectively connected with each single-tone source circuit,
the counter is used for generating a gating address of each single-tone source circuit;
the control platform is used for selecting one of the at least two single sound source circuits to be connected according to user requirements, generating a first signal and sending the first signal to the camera communication module;
the camera communication module is used for receiving and processing the first signal to obtain a gating pulse signal and sending the gating pulse signal to the counter;
the counter is also used for processing the gating pulse signal to obtain a first address and sending the first address to the analog electronic switch;
the analog electronic switch is used for processing the first address and selecting a corresponding single-tone source circuit to be switched on according to the processed first address.
3. The pickup system as set forth in claim 1, further comprising a transmission line through which said single sound source circuit and said second level adjustment circuit are connected;
the transmission line is used for transmitting the amplified audio signal to the second level adjustment circuit.
4. The sound pickup system as claimed in claim 3, wherein the single sound source circuit includes a microphone, a microphone automatic gain amplifier, a pre-amplifier circuit, a frequency selecting circuit and a first level adjustment circuit,
the output end of the microphone is connected with the input end of the microphone automatic gain amplifier, the output end of the microphone automatic gain amplifier is connected with the input end of the pre-stage amplifying circuit, the output end of the pre-stage amplifying circuit is connected with the input end of the frequency selecting circuit, the output end of the frequency selecting circuit is connected with the input end of the first level adjusting circuit, and the output end of the first level adjusting circuit is connected with the transmission line;
the microphone is used for collecting an original audio signal and sending the original audio signal to the microphone automatic gain amplifier;
the microphone automatic gain amplifier is used for processing the original audio signal to obtain a first amplified audio signal and sending the first amplified audio signal to the preceding stage amplifying circuit;
the preceding stage amplifying circuit is used for amplifying the first amplified audio signal to obtain a second amplified audio signal and sending the second amplified audio signal to the frequency selecting circuit;
the frequency selection circuit is used for selecting the second amplified audio signal to obtain a third amplified audio signal and sending the third amplified audio signal to the first level adjustment circuit;
the first level adjusting circuit is used for processing the third amplified audio signal to obtain an amplified audio signal and transmitting the amplified audio signal to the second level adjusting circuit by using the transmission line.
5. The pickup system as claimed in any one of claims 1 to 4, further comprising a filter circuit for filtering out noise, the filter circuit being connected in parallel with the second level adjustment circuit.
6. The pickup system as claimed in any one of claims 1 to 4, further comprising each of said single tone source circuits being supplied with a switching power supply or a linear power supply.
7. An external pickup method of a video camera, characterized in that the external pickup system of the video camera according to any one of claims 1 to 6 is adopted, comprising the steps of:
the single-tone source circuit collects and amplifies audio signals to obtain amplified audio signals, and sends the amplified audio signals to the second level adjusting circuit;
and the second level adjusting circuit compresses the amplified audio signal to obtain an audio signal of an audio acquisition device for sending to the camera.
8. The method of claim 7, wherein the external microphone system further comprises a control platform, an analog electronic switch, a camera communication module for communicating with the control platform, and a counter for connecting the camera communication module, and wherein at least two of the single-tone source circuits,
the counter generates a strobe address of each of the single-tone source circuits;
the control platform selects one of the at least two single sound source circuits to be connected according to user requirements, generates a first signal and sends the first signal to the camera communication module;
the camera communication module processes the first signal to obtain a gating pulse signal;
the counter processes the gating pulse signal to obtain a first address, and sends the first address to the analog electronic switch;
and the analog electronic switch processes the first address and selects a corresponding single-tone source circuit to be switched on according to the processed first address.
9. The method of claim 7, wherein the external microphone system further comprises a transmission line, and the transmission line transmits the amplified audio signal to the second level adjustment circuit.
10. The sound pickup method according to claim 9, wherein the single sound source circuit comprises a microphone, an automatic gain amplifier, a pre-amplifier circuit, a frequency selection circuit, and a first level adjustment circuit,
the microphone collects audio signals and sends the audio signals to the microphone automatic gain amplifier;
the microphone automatic gain amplifier processes the audio signal to obtain a first amplified audio signal and sends the first amplified audio signal to the preceding stage amplifying circuit;
the preceding stage amplifying circuit amplifies the first amplified audio signal to obtain a second amplified audio signal and sends the second amplified audio signal to the frequency selecting circuit;
the frequency selection circuit selects the second amplified audio signal to obtain a third amplified audio signal and sends the third amplified audio signal to the level adjustment circuit;
and the level adjusting circuit processes the third amplified audio signal to obtain an amplified audio signal and transmits the amplified audio signal to the second level adjusting circuit by using the transmission line.
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| CN202110149176.3A CN112995591A (en) | 2021-02-03 | 2021-02-03 | External pickup system and pickup method of camera |
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| CN202110149176.3A CN112995591A (en) | 2021-02-03 | 2021-02-03 | External pickup system and pickup method of camera |
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