CN103151031A - Camera system for high-fidelity automatic accompanying singing - Google Patents

Abstract

The invention discloses a high-fidelity automatic accompaniment singing camera system. Contains a video camera, accompaniment sound source MP3, microphone, signal processing circuit and playback system. The signal of the accompaniment sound source is mixed with the singing signal from the microphone through the attenuation circuit and then sent to the camera for recording, so that the recorded accompaniment music is high-fidelity stereo, which overcomes the high distortion of the accompaniment music recorded by the camera with the microphone. The signal of the accompaniment sound source is also sent to the sound playback system, and the sound is played through the speaker, so that the singer can sing according to the melody of the accompaniment music, which avoids the unsightly defect of the existing computer equipped with a camera microphone to record singing videos and can only be carried out with headphones. Since the microphone signal isolation circuit from the microphone to the playback system is set, no self-excited howling sound will occur. The invention has the advantages of high-quality performance effect of video camera and high-fidelity accompaniment music filmed by computer and camera microphone. The invention can be used for high-fidelity recording of singing videos with automatic accompaniment.

Description

High-fidelity automatic accompaniment singing camera system

technical field

The invention relates to a camera system, in particular to a high-fidelity automatic accompaniment singing camera system.

Background technique

Nowadays, there are more and more singing lovers at home and abroad, and more and more people record their own singing videos and upload them to major video websites to share with the public, and some people use them in TV talent shows and other activities. When using a video camera for singing video production, if you use pre-recorded accompaniment music instead of a band, it saves time and effort, and you can record on the spot with the camera and accompaniment sound turned on. In addition, there are many accompaniment music on the Internet, which makes it easy to make singing videos. However, since the accompaniment music is played by the speaker and then recorded by the microphone, the distortion of the audio signal becomes significantly larger, and the frequency response is also significantly worse, and the bass and treble in the accompaniment music are lost a lot; The distance between the two microphones is very close, so that the recorded accompaniment music has almost no stereoscopic effect, and the actual effect is similar to that of monophonic accompaniment. The actual accompaniment music effect of the singing video recorded by the above method is very poor. Of course, the automatic accompaniment singing camera system combined with a computer, camera and microphone can also record the singing video of personal high-fidelity accompaniment music, but the accompaniment music must be monitored with headphones when recording, and the sound cannot be played with speakers (even if it can be played with speakers). The sound must be very small, which not only has the above-mentioned defects, but also brings about the phenomenon that the volume of the accompaniment music is much smaller than the singing voice), otherwise it will form a positive feedback of the sound of the accompaniment music and self-excited howling. Therefore, the current personal singing videos on video sites are all recorded by computers, and the singers are singing with headphones (such as the video URL provided by Taobao sellers: http://detail.tmall.com/item.htm?spm= a1z0k.1000775.1.13.Nwhtrt&id=13043610870&_u=81m1lca8657), which greatly reduces the image of the singer and makes people feel that this is not a performance. Moreover, the camera cannot automatically focus, and other camera indicators are far from what the camera can compare, and the clarity and other indicators of the recorded video are far inferior to the camera.

Contents of the invention

The purpose of the present invention is to provide a high-fidelity automatic accompaniment singing camera system. Its accompaniment music is directly played by a loudspeaker at a large volume without self-excited howling due to the positive feedback received by the accompaniment music sound and the microphone, and the recorded accompaniment The music is taken from the electrical signal of the accompaniment source.

In order to achieve the above purpose, the present invention includes a video camera (10), a microphone (11), an accompaniment sound source (9), and a two-channel audio cable (7). One channel connection end of the accompaniment jack (1) is connected with the first resistor (R1) and the input end of the playback system (F), and the other end of the first resistor (R1) is connected with the second resistor (R2) and the first The capacitor (C1) is connected, the other end of the second resistor (R2) is grounded, the other end of the first capacitor (C1) is connected to the third resistor (R3), the other end of the third resistor (R3) is connected to the fourth resistor (R4) ) and one end of the output plug (3), the other end of the fourth resistor (R4) is connected to one input end of the microphone jack (2); the other channel connection end of the accompaniment jack (1) is connected to the sixth resistor (R6) is connected to the other input end of the playback system (11), the other end of the sixth resistor (R6) is connected to the seventh resistor (R7) and the second capacitor (C2), and the other end of the seventh resistor (R7) One end is grounded, the other end of the second capacitor (C2) is connected to the eighth resistor (R8), and the other end of the eighth resistor (R8) is connected to the ninth resistor (R9) and the other end of the output plug (3). The output plug (3) is plugged into the camera microphone jack (4), the microphone plug (12) is plugged into the microphone jack (2), and the plugs at both ends of the two-channel audio cable (7) are respectively connected to the accompaniment jack (1) and the headphone jack (8) of the accompaniment sound source (9).

In order to realize the isolation between the signal of the microphone (11) and the input end of the playback system (F), and prevent self-excited howling due to the positive feedback of the sound of the microphone signal, the present invention also sets the resistance value of the second resistor (R2) much smaller than that of the first resistor. The resistance value of the third resistor (R3), the seventh resistor (R7) is set much smaller than that of the eighth resistor (R8).

In order to adapt to the access of microphones with different types and different signal output strengths, the fifth resistor (R5) is connected in series with the first switch (K1) of the microphone volume adjustment switch (6) and then connected in parallel with the fourth resistor (R4). The ten resistor (R10) is connected in parallel with the ninth resistor (R9) after being connected in series with the second switch (K2) of the microphone volume adjustment switch (6).

Since the present invention sends the accompaniment signal of the accompaniment sound source (9) directly through the circuit of the present invention to the camera microphone socket (4) of the camera (10) for electrical signal recording when shooting a singing video, the recorded accompaniment signal High-fidelity and true stereo, the recording quality is almost the same as the accompaniment signal of the accompaniment sound source (9); in addition, the present invention also sends the accompaniment signal of the accompaniment sound source (9) to the input end of the playback system (F), Pronunciation through the horn (Y) makes the singer directly hear the accompaniment music, eliminating the unsightly and troublesome listening to the accompaniment music with headphones; because the circuit of the present invention includes the second resistor (R2), the third resistor (R3) and the second resistor (R2) The microphone signal isolation circuit composed of seven resistors (R7) and eighth resistor (R8) makes the microphone signal only transmitted to the camera (10) but not to the playback system (F), completely avoiding the microphone signal from passing through the playback system (F ) to amplify, and then return to the microphone to form the positive feedback of the sound and cause the self-excited howling. That is to say, the present invention has the advantages of the high-quality performance effect of camera shooting and the high-fidelity accompaniment filmed by the computer plus camera microphone. The setting of the microphone volume adjusting circuit in the present invention can allow the user to adjust the microphone volume very conveniently to adapt to different types of microphones, so that the recorded singing video has the best sound.

Description of drawings

Fig. 1 is a circuit diagram of Embodiment 1 of the present invention.

Fig. 2 is a circuit diagram of Embodiment 2 of the present invention.

Detailed ways

In Fig. 1, the video camera 10 can be used with an external microphone input jack, the microphone 11 can use a dynamic or condenser binaural microphone (also can use a mono), and the accompaniment sound source 9 can use sound sources such as common MP4 or MP3. The audio channel audio cable 7 can be an ordinary product on the market. A channel connection end of the accompaniment jack 1 is connected with the first resistor R1 and the input end of the sound reproduction system F. The other end of the first resistor R1 is connected to the second resistor R2 and the first capacitor C1, the other end of the second resistor R2 is grounded, the other end of the first capacitor C1 is connected to the third resistor R3, and the other end of the third resistor R3 is connected to the third resistor R3. The fourth resistor R4 is connected to one end of the output plug 3, and the other end of the fourth resistor R4 is connected to an input end of the microphone jack 2; the other channel connection end of the accompaniment jack 1 is connected to the sixth resistor R6 and the playback system The other input terminal of 11 is connected, the other end of the sixth resistor R6 is connected with the seventh resistor R7 and the second capacitor C2, the other end of the seventh resistor R7 is grounded, and the other end of the second capacitor C2 is connected with the eighth resistor R8, The other end of the eighth resistor R8 is connected with the ninth resistor R9 and the other input end of the output plug 3 . The output plug 3 is plugged into the camera microphone jack 4, the microphone plug 12 is plugged into the microphone jack 2, and the plugs at both ends of the two-channel audio line 7 are plugged into the accompaniment jack 1 and the earphone jack 8 of the accompaniment sound source 9 respectively.

In the present invention, the resistance value of the second resistor R2 is set much smaller than that of the third resistor R3, and the resistance value of the seventh resistor R7 is set much smaller than that of the eighth resistor R8. In this way, the signal from the microphone passes through the microphone signal isolation circuit (or a large attenuation circuit) composed of the fourth resistor R4, the third resistor R3, the first capacitor C1, and the second resistor R2 in series, and then from the second resistor R2 The microphone signal taken out is extremely weak (attenuated by thousands of times in this embodiment), and then sent to the playback system F through the first resistor R1, the self-excited howling caused by positive feedback of sound will not be generated. In the same way, the signal from the microphone passes through the microphone signal isolation circuit (or a large attenuation circuit) composed of the ninth resistor R9, the eighth resistor R8, the second capacitor C2, and the seventh resistor R7 in series, and then from the seventh resistor The other microphone signal taken out from R7 is extremely weak, and if it is sent to the other input end of the playback system F through the sixth resistor R6, the self-excited howling caused by positive feedback of sound will not be produced.

The eleventh resistor R11 and the twelfth resistor R12 mix the two-way stereo accompaniment signals and add them to both ends of the resistor R13, send them to the volume potentiometer W through the third capacitor C3, and then send them to the audio amplifier 5 for power amplification. Sent to the loudspeaker Y to emit the sound of the accompaniment music, the singer can sing along with the accompaniment music, which avoids the trouble of wearing earphones to monitor the accompaniment music and defects such as unsightly. Because the resistors R11 and R12 mix the two-way stereo accompaniment signals and then send them to the playback system F, a single-channel playback system can be used, which simplifies the circuit and reduces the cost. And the resistance value of resistors R11, R12 is much larger than that of resistors R1, R2, R6, R7, so it has no effect on the two-way stereo separation of the accompaniment signal sent to output plug 3 through resistors R1, R2, R6, R7, and will not produce Two-channel signals are mixed. The power supply positive input +E of the power supply of the audio amplifier 5 can be a 3-12V DC stabilized power supply, or a rechargeable battery, so that the mobility is better.

The fifth resistor R5 is connected in series with the first switch K1 of the microphone volume adjustment switch 6 and then connected in parallel with the fourth resistor R4, and the tenth resistor R10 is connected in series with the second switch K2 of the microphone volume adjustment switch 6 and then connected with the ninth resistor R9 in parallel. In this way, when the above two switches are turned on, the microphone signal sent to output plug 3 is strengthened (suitable for dynamic microphones with weak output signals); when the switch is turned off, the microphone signal sent to output plug 3 is weakened (suitable for Condenser microphones with strong output signals). This is more convenient and reliable than the volume adjustment of the microphone with potentiometer structure, and it is not easy to cause faults such as poor contact and adjustment errors. The first switch K1 and the second switch K2 are mechanically linked toggle switches, which are turned on or off synchronously.

In Fig. 1, except video camera 10, accompaniment sound source 9, microphone 11, microphone plug 12, two-channel audio line 7, output plug 3, all are installed in a casing, accompaniment jack 1, microphone jack 2, microphone The volume adjustment switch 6 is all fixed on the front panel of the casing, and the other end of the connecting line of the output plug 3 (with a shielded two-core microphone line) is also mechanically fixed on the casing.

Because the output of the accompaniment sound source 9 is that the earphone voltage is more than several hundred millivolts, and the microphone input signal of the video camera 10 is generally several millivolts, so it must be attenuated dozens of times before being sent to the video camera. The resistors R1, R2, R6, and R7 are A two-way attenuation circuit is formed.

In the present invention, circuits other than camera 10, accompaniment sound source 9, microphone 11, microphone plug 12, two-channel audio line 7, output plug 3, and playback system F are collectively referred to as signal processing circuits.

The parameters of each component in this embodiment are as follows:

Resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13 are 0.1, 0.005, 2.4, 3, 1, 0.1, 0.005, 2.4, 3, 1, 2.7, 2.7, 15 kiloohms, capacitors C1, C2, and C3 are all 100 microfarads. The audio amplifier 5 can use various prior art circuit structures, and it is recommended to use an integrated power amplifier (refer to the patent name: three-phase circuit experiment instrument, the amplifier circuit structure in Chinese Patent No. 200910231005.4). The video camera uses a standard-definition video camera with a stereo microphone jack for a few hundred yuan (a Japanese-made Canon SR10 video camera that costs 700 yuan is very good). Accompaniment sound source 9 just can be with common MP3 or MP4, and its accompaniment volume can be adjusted, also band volume display, and MP4 (or MP5) also has subtitle, uses very convenient. All sockets and plugs are available in the market with a diameter of 3.5 mm.

I am a bel canto singing amateur, and I made a sample according to the present invention, and the filming effect is very good. There is no difference between the recorded accompaniment music and the accompaniment sound source, and its frequency response, fidelity, and stereo separation effect all good. Although the microphone also receives the sound signal of part of the accompaniment music, but because its intensity is much smaller than that transmitted directly through the circuit, the accompaniment music released by the playback system cannot be heard in the recorded singing video. In addition, although the camera used is a low-end standard-definition Canon SR10 camera with a few hundred yuan, the image effect is obviously better than the high-definition camera used by the computer, because the camera has automatic focus, the focus is accurate and timely, and the focus can be automatically and quickly changed according to the position of the singer. The recorded video image has a high definition, and other indicators of the lens far exceed those of a computer camera. That is to say, the present invention has the advantages of the high-quality performance effect of the video camera and the high-fidelity accompaniment music produced by the computer plus the camera microphone.

Fig. 2 is the circuit embodiment of changing the present invention into two-channel playback system. The second road playback system is exactly the same as the first road, and the circuit is no longer described. Its advantage is that the accompaniment music is stereo, but the cost increases, and the product volume and weight all increase.

The present invention can have multiple changes, for example, the circuit that the microphone signal is isolated from the playback system can be changed into an active isolation circuit with triode; The other end of the channel audio cable is welded with a dual-channel plug, and it can be directly inserted into the headphone jack of the accompaniment sound source when in use; the output plug 3 can also be replaced with a dual-channel jack (same as the microphone jack) and fixed on the case Go up, get final product with two-channel audio line 7 plugging between two-channel jack and camera microphone socket 4;

Claims (4)

1. a high-fidelity automatic accompaniment is sung camera system, comprise video camera (10), accompaniment source of sound (9), connect with microphone cord (13) between microphone (11) and phono connector (12), dual-channel audio line (7), the sound channel link of jack (1) of it is characterized in that accompanying is connected with the input end of the first resistance (R1) and playback system (F), the other end of the first resistance (R1) is connected with the second resistance (R2) and the first electric capacity (C1), the other end ground connection of the second resistance (R2), the other end of the first electric capacity (C1) is connected with the 3rd resistance (R3), the other end of the 3rd resistance (R3) is connected with an end of the 4th resistance (R4) and output plug (3), the other end of the 4th resistance (R4) is connected with an input end of microphone jack (2), another sound channel link of accompaniment jack (1) is connected with another input end of the 6th resistance (R6) and playback system (11), the other end of the 6th resistance (R6) is connected with the 7th resistance (R7) and the second electric capacity (C2), the other end ground connection of the 7th resistance (R7), the other end of the second electric capacity (C2) is connected with the 8th resistance (R8), the other end of the 8th resistance (R8) is connected with the other end of the 9th resistance (R9) and output plug (3), output plug (3) is pegged graft with video camera microphone socket (4), phono connector (12) is pegged graft with microphone jack (2), the two ends plug of dual-channel audio line (7) is pegged graft with the earphone jack (8) of accompaniment jack (1) and accompaniment source of sound (9) respectively.

2. sing camera system by high-fidelity automatic accompaniment claimed in claim 1, it is characterized in that the resistance of the second resistance (R2) much smaller than the 3rd resistance (R3), the resistance of the 7th resistance (R7) is much smaller than the 8th resistance (R8).

3. sing camera system by high-fidelity automatic accompaniment claimed in claim 1, it is characterized in that the resistance of the 11 resistance R 11 and the 12 resistance R 12 is much larger than the first resistance (R1) and the 6th resistance (R6).

4. sing camera system by high-fidelity automatic accompaniment claimed in claim 1, in parallel with the 4th resistance (R4) again after it is characterized in that the 5th resistance (R5) and the first via switch (K1) of microphone volume adjusting switch (6) being connected, the tenth resistance (R10) is with in parallel with the 9th resistance (R9) again after second way switch (K2) of microphone volume adjusting switch (6) is connected.

Images