Audio and video transmission device and audio and video transmission system

Abstract

The embodiments of this specification provide an audio and video transmission system and an audio and video transmission device, the system comprising an audio and video transmission device and at least one wireless microphone transmitting device; the wireless microphone transmitting device is used to send the audio signal collected by the wireless microphone to the audio and video transmission device; the audio and video transmission device is used to connect to the video acquisition device and the wireless microphone transmitting device respectively, receive the audio signal and transmit the audio signal to the video acquisition device, and obtain the mixed signal generated by the audio signal and the video signal from the video acquisition device, and output the mixed signal after processing. The audio and video transmission system provided by the embodiments of this specification can realize the collection of audio signals in shooting scenes where the audio signal source is far away from the video acquisition device, and the transmission of audio and video signals and audio and video mixed signals, and ensure the quality of the audio signal.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to an audio and video transmission device and an audio and video transmission system. Background Art

[0002] In scenes such as film and television shooting, commercial video shooting, and personal shooting, when shooting a video of the subject, it is necessary to simultaneously collect the video signal of the subject and the audio signal that needs to be played synchronously with the video signal, and then perform synchronization alignment processing on the video signal and the audio signal to obtain the final audio and video mixed signal and transmit it to the video receiving end. Usually, when a camera device is used to shoot a video, the video signal of the subject can be collected by the camera device, and the audio signal can be collected by the built-in microphone of the camera device at the same time. The audio and video mixed signal generated after synchronization processing is sent to the video receiving end through wireless transmission technology. However, the built-in microphone is only suitable for scenes where the audio signal source is close to the camera device. If the two are far apart, the collection effect of the built-in microphone will be poor. In addition, due to the noise interference generated by the motor, fan, etc. on the camera device, the quality of the collected audio signal cannot be guaranteed. Summary of the invention

[0003] Based on this, the embodiments of this specification provide an audio and video transmission system and an audio and video transmission device.

[0004] According to a first aspect of an embodiment of this specification, there is provided an audio and video transmission system, the system comprising an audio and video transmission device and at least one wireless microphone transmitting device;

[0005] The wireless microphone transmitting device is used to send the audio signal collected by the wireless microphone to the audio and video transmission device;

[0006] The audio and video transmission device is used to connect to the external video acquisition device and the wireless microphone transmitting device respectively, receive the audio signal, transmit the audio signal to the video acquisition device, and obtain the mixed signal generated by the audio signal and the video signal from the video acquisition device, and output the mixed signal after processing.

[0007] According to a second aspect of the embodiments of this specification, an audio and video transmission device is provided, wherein the audio and video transmission device is respectively connected to an external video acquisition device and a wireless microphone transmitting device, and the audio and video transmission device comprises:

[0008] An audio transmission unit, used to receive an audio signal collected by a wireless microphone from the wireless microphone transmitting device, and transmit the audio signal to the video collection device;

[0009] The video transmission unit is used to obtain a mixed signal obtained by mixing the audio signal and the video signal from the video acquisition device, and output the mixed signal.

[0010] The embodiment scheme of this specification is applied, and the audio signal of the audio signal source is collected by using a wireless microphone separated from the video acquisition device in a physical entity. The collected audio signal is not directly transmitted to the video acquisition device by the wireless microphone, but is transmitted by an audio and video transmission system. The audio and video transmission system has a wireless microphone transmitting device and an audio and video transmission device. The audio signal is sent by the wireless microphone transmitting device to the audio and video transmission device, and then transmitted to the video acquisition device by the audio and video transmission device. In order to utilize the existing functions of the video acquisition device, when designing this scheme, the video acquisition device can still complete the synchronous processing of the audio signal and the video signal, generate an audio and video mixed signal, and output the mixed signal to the audio and video transmission device, so that the audio and video transmission device sends the mixed signal to the video receiving end, so there is no need to change the existing functions of the video acquisition device. The scheme of the embodiment of this specification can realize the audio signal collection of the shooting scene where the audio signal source is far away from the video acquisition device, and the transmission of the audio signal and the audio and video mixed signal. By placing the microphone in a position convenient for collecting the audio signal source to collect the audio signal, the quality of the collected audio signal can be improved, and the effect of the final collected audio and video can be guaranteed. Moreover, through the self-designed audio and video transmission device, the transmission of audio signals and audio and video mixed signals can be realized simultaneously, which solves the transmission problem of audio signals and audio and video mixed signals in shooting scenes where the audio signal source and the video acquisition device are far apart. The transmission of two signals is realized by one device, which also simplifies the installation process of the equipment during shooting.

[0011] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the specification and, together with the description, serve to explain the principles of the specification.

[0013] Figure 1 It is a schematic diagram of an audio and video transmission system according to an embodiment of the present specification.

[0014] Figure 2-6 It is a structural diagram of an audio and video transmission device according to an embodiment of this specification.

[0015] Figure 7 It is a structural diagram of an audio transmission unit according to an embodiment of the present specification.

[0016] Figure 8It is a structural diagram of a video transmission unit according to an embodiment of the present specification.

[0017] Fig. 9 It is a schematic diagram of an audio and video transmission system according to an embodiment of the present specification.

[0018] Fig.10 It is a schematic diagram of the structure of a wireless microphone according to an embodiment of the present specification.

[0019] Fig.11 It is a schematic diagram of the structure of an audio and video transmission device according to an embodiment of the present specification.

[0020] Fig.12 It is a schematic diagram of the structure of a wireless video receiving terminal according to an embodiment of the present specification. DETAILED DESCRIPTION

[0021] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with this specification. Instead, they are merely examples of devices and methods consistent with some aspects of this specification as detailed in the appended claims.

[0022] The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this specification. The singular forms "a", "the" and "the" used in this specification and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0023] It should be understood that although the terms first, second, third, etc. may be used in this specification to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this specification, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0024] In film and television shooting, commercial video shooting or personal video shooting scenes, the video signal can be collected from the object being photographed and the audio signal can be collected from the audio signal source at the same time through the camera device, and the audio signal and the video signal are synchronously processed to obtain an audio-video mixed signal, and then output to the video receiving end. In some scenes, the video receiving end is far away from the camera device. Therefore, the audio-video mixed signal collected by the camera device can be sent to the video receiving end through wireless transmission technology so that it can be viewed remotely at the video receiving end. At present, when the camera device collects the audio signal of the object being photographed, it mostly uses the built-in microphone of the camera device to collect it. This method is more suitable when the camera device is close to the audio signal source, but when the camera device is far away from the audio signal source, the quality of the collected audio signal is poor, which affects the playback effect.

[0025] Based on this, the embodiments of this specification provide an audio and video transmission device and an audio and video transmission system for realizing the collection of audio signals and the transmission of audio signals and audio and video mixed signals in a shooting scene where the audio signal source and the video collection device are far apart.

[0026] like Figure 1 As shown, the audio and video transmission system 10 may include an audio and video transmission device 11 and a wireless microphone transmitting device 12. The number of wireless microphone transmitting devices 12 is not limited. Figure 1 Two wireless microphone transmitting devices 12 are shown as examples. Among them, a wireless microphone transmitting device 12 is connected to a wireless microphone 13, and is used to send the audio signal of the audio signal source collected by the wireless microphone 13 to the audio and video transmission device 11. The audio and video transmission device 11 is also connected to a video acquisition device 14, and the video acquisition device 14 is used to collect the video signal of the object being photographed. The audio and video transmission device 11 sends the audio signal received from the wireless microphone transmitting device 12 to the video acquisition device 14, so that the video acquisition device 14 synchronously processes the audio signal and the video signal of the object being photographed, generates an audio and video mixed signal (hereinafter referred to as the mixed signal), and outputs the mixed signal to the audio and video transmission device 11, so that the audio and video transmission device 11 outputs the mixed signal.

[0027] There may be many examples of audio signal sources. For example, the audio signal source may be the subject being filmed, or other sound sources that need to be played synchronously with the video of the subject being filmed (such as the voice of a narrator narrating the video), etc.

[0028] In the long-distance shooting scene, since the audio signal source is far away from the video acquisition device 14, if the built-in microphone of the video acquisition device 14 is used, the sound reception effect is poor. In this application, an external wireless microphone 13 is used. In order to collect clearer audio signals and improve the quality of audio signals, the wireless microphone 13 can be placed close to the audio signal source. For example, if the audio signal source is the narrator of the video, the wireless microphone 13 can be carried on the narrator. In order to facilitate carrying, the wireless microphone transmitting device 12 and the wireless microphone 13 can be designed in an integrated manner, for example, they can be designed as handheld or small integrated clip-on. After the wireless microphone 13 collects the audio signal of the audio signal source, it is sent to the audio and video transmission device 11 through the wireless microphone transmitting device 12. The wireless microphone transmitting device 12 can send the collected audio signal to the audio and video transmission device 11 through various wireless transmission technologies, such as Bluetooth, WIFI, Zigbee and other wireless transmission technologies. Considering the transmission distance and transmission effect, WIFI transmission technology is usually selected in the shooting scene where the audio signal source is far away from the video acquisition device 14. For example, the collected audio signal may be modulated by digital modulation, and the modulated audio signal may be transmitted via a 1.9 GHz DECT (Digital Enhanced Cordless Telecommunications), 2.4 GHz ISM or 5 GHz ISM frequency band.

[0029] Usually, in order to meet the needs of on-site stereo or multi-channel sound collection, an audio and video transmission device 11 can be connected to at least two wireless microphone transmitting devices 12 at the same time, and each wireless microphone transmitting device 12 sends the audio signal collected by the wireless microphone 13 connected thereto to the audio and video transmission device 11. When an audio and video transmission device 11 is connected to multiple wireless microphone transmitting devices 12, a TDMA (Time Division Multiple Access) transmission method can be adopted, and different wireless microphone transmitting devices 12 occupy different time slots. When multiple wireless microphone transmitting devices 12 and the audio and video transmission device 11 perform data transmission, they only occupy one independent wireless channel.

[0030] The audio and video transmission device 11 and the video acquisition device 14 may be connected physically or wirelessly. Usually, the audio and video transmission device 11 may be placed near the video acquisition device 14. For example, the video acquisition device 14 may be provided with a physical interface connected to the audio and video transmission device 11. The two may be connected via the physical interface. Of course, in order to save space and facilitate the movement of the video acquisition device 14 and the audio and video transmission device 11 during shooting, the audio and video transmission device 11 may be fixedly mounted on the video acquisition device 14.

[0031] After receiving the audio signal sent by the wireless microphone transmitter 12, the audio and video transmission device 11 can input the audio signal to the video acquisition device 14. The video acquisition device 14 performs synchronization and alignment processing on the received audio signal and the acquired video signal, generates a mixed signal after the audio signal is accompanied by the video signal, and then outputs the mixed signal to the audio and video transmission device 11. The audio and video transmission device 11 processes the mixed signal and then outputs it. For example, in some embodiments, the audio and video transmission device 11 can have components such as a display screen, and decode the mixed signal and output it to a display interface for users to watch.

[0032] In some embodiments, the audio and video transmission device 11 can also send the mixed signal to other video receiving terminals so that users can watch videos through the video receiving terminals. For example, in many video shooting scenes, the director needs to remotely monitor the shooting effect. At this time, the mixed signal can be sent to the remote monitoring device so that the director can monitor the shooting effect. In order to achieve long-distance transmission without wiring, the audio and video transmission device 11 can also output the mixed signal to the video receiving terminal through wireless transmission technology, such as Bluetooth, WIFI, Zigbee and other wireless transmission technologies. Considering the shooting scene where the audio signal source is far away from the video acquisition device 14, the transmission distance may be far, and the video data volume is large, WIFI transmission can be selected. For example, after the mixed signal is encoded using a general video compression coding technology (such as H.264 / H.265), a general WIFI transmission technology is used, such as 2.4GHz, 5GHz UNII WIFI and 60GHz 802.11d WIFI to transmit the mixed signal to the video receiving terminal. The video receiving end can be an intelligent terminal with general WIFI connection function and general H.264 / H.265 video decoding capability, such as personal terminals such as mobile phones and computers, or it can be an independent device with stronger hardware H.264 / H.265 decoding capability and stronger wireless WIFI performance.

[0033] The audio and video transmission system in the embodiment of this specification collects the audio signal of the audio signal source through the wireless microphone 13, and then sends it to the audio and video transmission device 11 through the wireless microphone transmitting device 12. The audio and video transmission device 11 inputs the audio signal to the video acquisition device 14, and the video acquisition device 14 synchronizes the audio signal and the collected video signal to generate a mixed signal, and then outputs the mixed signal to the audio and video transmission device 11, and the audio and video transmission device 11 outputs the mixed signal. The audio signal of the audio signal source is collected by the external wireless microphone 13, which can improve the quality of the audio signal, and the audio and video signal can be transmitted by the self-designed audio and video transmission device 11, and the audio signal is input to the video acquisition device 14 to synchronize the audio signal and the video signal to generate an audio and video mixed signal. In addition, the audio and video transmission device 11 can also realize the transmission of the mixed signal at the same time, and send the audio and video mixed signal to the video receiving end. Through an audio and video transmission device 11, the transmission of audio signals and audio and video mixed signals is realized at the same time, which is convenient for the installation of equipment during the shooting process, and can solve the audio collection and transmission problems of long-distance shooting scenes, and improve the effect of the final collected audio and video.

[0034] like Figure 2 As shown, the audio and video transmission device 11 provided in the embodiment of this specification may include a video transmission unit 110 and an audio transmission unit 111. The audio transmission unit 111 receives the audio signal transmitted by the wireless microphone transmitting device 12 through a wireless transmission channel and transmits it to the video acquisition device 14. The video transmission unit 110 sends the mixed signal of the audio signal and the video signal output by the video acquisition device 14 synchronized through the wireless transmission channel to the video receiving end 15.

[0035] In some embodiments, the audio and video transmission device 11 can transmit the audio signal and the mixed signal independently, for example, Figure 3As shown, the audio and video transmission device 11 may include a video transmission unit 110, an audio transmission unit 111, an accessory 112 and multiple antennas (113 and 114 in the figure), and the accessory 112 may include a battery, a button, a display screen, a casing, etc. The video transmission unit 110 and the audio transmission unit 111 each use an independent wireless transmission channel and antenna to transmit data through their respective wireless transmission channels. For example, the audio transmission unit 111 can receive the audio signal sent by the wireless microphone transmitting device 12 through the antenna 114, and output it to the video acquisition device 14. The video transmission unit 110 obtains the mixed signal from the video acquisition device 14 and sends the mixed signal to the video receiving end 15 through the antenna 113. In order to avoid mutual interference caused by the transmission of the two signals, the video transmission unit 110 and the audio transmission unit 111 can operate in different frequency bands. For example, the video transmission unit 110 operates on UNII 5GHz WIFI, while the audio transmission unit 111 operates on UHF (Ultra High Frequency) or 2.4GHz. Of course, in some embodiments, such as Figure 4 As shown, in order to reduce the number of antennas, the audio and video transmission device 11 can also include a dual-frequency duplex filter 116 and a dual-frequency antenna 115. The RF combining is realized by the dual-frequency duplex filter 116, and then transmitted by the dual-frequency antenna 115, so as to reduce the number of antennas.

[0036] Of course, since the audio signal and the mixed signal each use an independent transmission channel, they occupy wireless transmission channel resources, for example, at least two wireless channels must be occupied, and the transmission of the two signals will also cause mutual interference. In order to reduce the occupation of wireless transmission channel resources and reduce the interference between the two signal transmissions. In some embodiments, the audio and video transmission device 11 can use the same wireless channel to transmit the audio signal and the mixed signal in a time-division multiplexing manner, that is, the audio signal and the mixed signal can use a unified wireless transmission technology, for example, WIFIIEEE802.11 transmission technology can be uniformly adopted. Since the wireless video signal transmission characteristic is that the code stream bandwidth is high, but a long time delay can be accepted, and the wireless microphone audio signal is characterized by low code stream bandwidth, but the delay requirement is more stringent, so the two signals are transmitted through the same wireless channel, which can take into account the characteristics of small bandwidth occupation, low power consumption, low delay parameters of the wireless microphone audio signal, and can also ensure the high transmission bandwidth requirements of the wireless video signal, each taking what is needed. In addition, audio signals and mixed signals can be transmitted via the 2.4GHz, 5GHz UNII or 60GHz ISM bands, which can ensure the high-speed bandwidth requirements of wireless video transmission, while the 5GHz UNII and 60GHz ISM bands with less interference can also provide more reliable protection for the real-time transmission of audio signals.

[0037] In some embodiments, both the audio signal and the mixed signal are transmitted using WIFI technology, and the two signals can share the WIFI transmission channel. Figure 5 As shown, the audio and video transmission device may also include a WIFI transmission unit 117. The video transmission unit 110 and the audio transmission unit 111 may share the WIFI transmission unit 117. The audio transmission unit 111 receives an audio signal from the wireless microphone transmitting device 12 via the WIFI transmission unit 117, and the video transmission unit 110 sends the mixed signal to the video receiving end 15 via the WIFI transmission unit 117.

[0038] In certain embodiments, such as Figure 6 As shown, the audio and video transmission device 11 also includes a central processing unit 118, which is used to receive a mixed signal from the video transmission unit 110, compress and encode the audio signal and the video signal in the mixed signal, and then output it to the WIFI transmission unit 117, so that the WIFI transmission unit 117 can transmit it to the video receiving end 15, and receive the audio signal sent by the wireless microphone transmitting device 12 from the WIFI transmission unit 117, convert it into a digital compressed audio signal, and then send it to the audio transmission unit 111. When the WIFI transmission unit 117 in the audio and video receiving device 11 receives the audio signal from the wireless microphone transmitting device 12, it can first send the audio signal to the central processing unit 118, and the central processing unit 118 converts the audio signal into a digital compressed audio signal. The format of the converted digital compressed audio signal is the same as the format of the audio signal sent by the wireless microphone transmitting device 12, and can be one encoded by an open source encoding algorithm such as ADPCM, Opus-CELT, etc. The central processing unit 118 then sends the digital compressed audio signal to the audio transmission unit 110, so that the audio transmission unit 110 further processes the analog audio signal and then outputs it to the video acquisition device 14. At the same time, the video acquisition device 14 synchronously processes the audio signal input by the audio transmission unit 111 and the collected video signal to generate an audio-video mixed signal, and outputs the mixed signal to the video transmission unit 110. The video transmission unit 110 sends the mixed signal to the central processing unit 118, so that the central processing unit 118 compresses and encodes the audio signal in the mixed signal and the video signal in the mixed signal to obtain an encoded mixed signal, and then outputs the encoded mixed signal to the WIFI transmission unit 117, which is sent to the video receiving end 15 through the WIFI transmission unit 117. In some implementations, the central processing unit 118 can be a SOC chip with integrated CPU and H.264 / H.265 codec functions.

[0039] In certain embodiments, such as Figure 7As shown, the audio transmission unit 111 may include an audio processing subunit 111a, a sampling subunit 111b and a first interface subunit 111c, wherein the audio processing subunit 111a is used to obtain the digital compressed audio signal converted by the central processing unit 118, and decode the digital compressed audio signal, and at the same time, it can also complete the processing of equalization, sound effect, noise reduction, and volume level adjustment of the digital compressed audio signal. The sampling subunit 111b is used to sample and restore the digital compressed audio signal after decoding to obtain an analog audio signal. In some embodiments, the sampling subunit 111b can be a multi-channel audio sampling DAC (Digital to Analog Converter). The first interface subunit 111c is used to output the analog audio signal obtained by sampling and restoration to the video acquisition device 14, so that the video acquisition device 14 synchronizes the audio signal obtained by sampling and restoration with the collected video signal. Among them, the first interface subunit 111c includes a multi-channel amplification processor, which is used to perform multi-channel audio amplification processing on the analog audio obtained by sampling and restoration, so as to output an analog audio signal whose amplitude meets the level requirements of the external microphone input interface of the video acquisition device 14.

[0040] In certain embodiments, such as Figure 8 As shown, the video transmission unit 110 may include a second interface subunit 110a and a video signal processing subunit 110b. The second interface subunit 110a is used to receive the mixed signal from the video acquisition device 14, separate the audio signal and the video signal in the mixed signal, and transmit the audio signal in the mixed signal to the central processing unit 118 for compression encoding processing. The video signal processing subunit 110b is used to process the video signal and then send it to the central processing unit 118 for compression encoding processing. In some embodiments, the second interface subunit 110a includes an SDI video receiver, an HDMI video receiver, and the video acquisition device 14 outputs an interface signal of the SDI and HDMI standards, which is a mixed signal including an audio signal and a video signal, wherein the video signal in the mixed signal is converted into a standard digital parallel video signal by the SDI video receiver and the HDMI video receiver, and the signal format is BT1120 or MIPI, and then sent to the video processing subunit 110b, which can be an FPGA chip, and the FPGA chip selects a video signal to send to the central processing unit 118, so that the central processing unit 118 can compress and encode the video signal. The audio signal in the mixed signal is directly output to the central processing unit 110, and is compressed and encoded separately from the video signal.

[0041] In some embodiments, the audio and video transmission device 11 also includes a CCU (Camera Control Unit) control interface, and the central processing unit 118 controls the CCU of the video acquisition device 14 through the CCU control interface to complete the adjustment of the lens, image parameters, and auxiliary data of the video acquisition device 14.

[0042] In some embodiments, the audio and video transmission device 11 further includes an expansion interface connected to the central processing unit 118, which is used to connect one or more of the following accessories: LCD screen, button, power supply. For example, the audio and video transmission device 11 may include accessories such as screen, button, power supply, etc. These accessories are connected to the central processing unit 118 through the expansion interface so that the central processing unit 118 can control these accessories.

[0043] In some application scenarios, after receiving the mixed signal output by the video acquisition device 14, the audio and video transmission device 11 can send it to other video receiving terminals 15. For example, in the field of film and television shooting or commercial shooting, the audio and video mixed signal collected by the video acquisition device 14 needs to be sent to the video receiving terminal 15 so that the director, lighting technician and other staff can make corresponding adjustments according to the effect of the video. In order to facilitate these workers to view the filmed video, in some embodiments, the audio and video transmission system 10 can also include an APP installed on the electronic device as the video receiving terminal 15. The audio and video transmission device 11 can send the mixed signal after the audio and video signal is synchronized to the APP so that the user can view the filmed audio and video through the APP. The electronic device can be a user's mobile phone, tablet, computer and other terminal devices. The user pre-installs a specified APP on the electronic device and receives the mixed signal after the audio and video signal is synchronized from the audio and video transmission device 11 through the APP.

[0044] In some embodiments, the audio and video transmission device 11 can be connected to the wireless microphone transmitting device 12 and the electronic device installed with the APP through a WIFI channel, and the working mode of the WIFI transmission unit of the audio and video transmission device 11 is AP mode, and the working mode of the WIFI transmission unit of the wireless microphone transmitting device 12 and the electronic device installed with the APP is Station mode. For example, the audio and video transmission device 11 can turn on the WIFI hotspot, the wireless microphone transmitting device 12 and the electronic device installed with the APP can search for the SSID of the audio and video transmission device 11, and establish a WIFI connection with the audio and video transmission device 11 through a preset password. Then the wireless microphone transmitting device 12 can transmit an audio signal to the audio and video transmission device 11 through the established WIFI connection channel, and the electronic device installed with the APP can receive a mixed signal from the audio and video transmission device 11 through the established WIFI connection channel.

[0045] The wireless microphone audio signal used in the field of video shooting generally requires a very low transmission delay, usually less than 10ms, and has a transmission distance of 50 to hundreds of meters. The transmission of wireless microphone audio signals has strict requirements on the delay because: if the delay is serious, the sound and image will be out of sync, which seriously affects the final video effect. Therefore, it is very important to reduce the delay of the wireless microphone audio signal transmission. The reasons for the delay of the audio signal transmitted by the wireless microphone 13 mainly include the following aspects: First, after the wireless microphone 13 collects the audio signal of the audio signal source, the wireless microphone transmitting device 12 usually needs to compress and encode the audio signal, and then send it to the audio and video transmission device 11 through the wireless channel. Usually, the audio signal can be encoded frame by frame. Therefore, when collecting audio signals, the collected audio data will be cached first, and the encoding will be performed after the length of the cached audio data reaches one frame. The wireless microphone transmitting device 12 will also produce a certain delay in the process of waiting for the collected audio data to reach the length of one frame. This delay is related to the frame length of the audio data. Second, the process of compressing the audio signal takes a certain amount of time, which will cause a part of the delay. Correspondingly, after the audio and video transmission device 11 receives the audio signal, it needs to decode it, and the decoding process will also cause a certain delay. Third, after the encoding is completed, when the audio signal is sent in time slots, a certain air interface time slot delay will be generated between time slots. Fourth, when the audio signal is sent from the wireless microphone transmitting device 12 to the audio and video transmission device 11, a certain sending and receiving delay will be generated.

[0046] In some embodiments, in order to reduce the delay caused by audio signal encoding and decoding, a low-delay and low-loss compression technology can be used to compress and encode the audio signal when compressing and encoding the audio signal. The low-delay and low-loss compression technology can be one of OPUS-CELT, ADPCM (Adaptive Differential Pulse Code Modulation), LC3, and LC3plus.

[0047] Because when low-delay and low-loss compression technologies such as OPUS-CELT, ADPCM, LC3, and LC3plus compress audio signals, the frame length of each frame of the compressed audio signal can be set by itself, and for audio signals with short frame structures, the quality of the compressed audio signal can also be guaranteed. Therefore, in some embodiments, in order to reduce the delay caused by the first aspect mentioned above, the frame length of the audio signal collected by the wireless microphone 13 can be configured to be less than the specified length, and the frame length of the audio signal can use a short frame structure as much as possible, for example, less than 2.5ms, so as to reduce the waiting delay caused by the in-frame cache of the audio signal. Of course, the specified length can be set according to the actual situation, for example, it can be set to the minimum frame length supported by the above-mentioned low-delay and low-loss compression technology.

[0048] In some embodiments, since the audio signal transmission and the mixed signal transmission share a wireless transmission channel, and the audio signal has a higher delay requirement than the audio and video mixed signal, in order to reduce the transmission delay of the audio signal, the priority of the audio signal being transmitted is higher than the priority of the mixed signal being transmitted, ensuring that the wireless microphone audio signal is transmitted first, thereby reducing its sending and receiving delay and improving the reliability of transmission. Of course, in addition to transmitting audio signals, some control instructions are also transmitted between the wireless microphone transmitting device 12 and the audio and video transmission device 11. Among the various data transmitted by the audio and video transmission device 11, the transmission priority of the audio signal can be set to the highest to ensure that the audio signal is transmitted first. For example, the wireless microphone transmitting device 12 and the audio and video transmission device 11 both use WIFI transmission technology, and the WIFI transmission units of the wireless microphone transmitting device 12 and the audio and video transmission device 11 can support the WMM QOS mechanism, and the priority of each transmission signal is set through the WMM QOS mechanism.

[0049] Since both the audio signal and the mixed signal use WIFI transmission technology, compared with Bluetooth technology and Zigbee technology, WIFI technology consumes more power. In the field of video shooting, it is usually necessary to design the wireless microphone 13 and the wireless microphone transmitting device 12 into an integrated form, so that the overall size of the wireless microphone device is smaller and the weight is lighter, which is convenient for the subject to wear and install. This requires the power supply battery to be smaller in size, and thus the battery capacity is also smaller. Therefore, how to reduce the power consumption of the wireless microphone transmitting device 12 is also very critical.

[0050] In some embodiments, the wireless microphone transmitting device 12 transmits an audio signal to the audio and video transmission device 11 using WIFI technology. Both the wireless microphone transmitting device 12 and the audio and video transmission device 11 include a WIFI transmission unit. In order to reduce the power consumption of the wireless microphone transmitting device 12, the WIFI transmission unit of the wireless microphone transmitting device 12 can alternately work in a dormant state and a wake-up state. The dormant state has lower power consumption. The WIFI transmission unit of the wireless microphone transmitting device 12 does not have to be in the wake-up state all the time, which can reduce power consumption. For example, in some embodiments, the WIFI transmission unit of the wireless microphone transmitting device 12 switches from the dormant state to the wake-up state at a preset time interval, and after completing the transmission task in this wake-up state, it switches from the wake-up state to the dormant state. The transmission task may refer to tasks such as sending the audio signal collected by the wireless microphone 13 to the audio and video transmission device 11 and receiving control instructions from the audio and video transmission device 11. For example, the WIFI transmission unit of the wireless microphone transmitting device 12 can wake up from the dormant state every 3ms. After waking up, it first sends the audio signal to the audio and video transmission device 11, and then receives the control instruction sent by the audio and video transmission device 11. After completion, it enters the dormant mode again.

[0051] The key to saving power for the WIFI transmission unit is to reduce the duration of the transmission time slot as much as possible, so the duration of the transmission time slot can be reduced from the following aspects: First, reduce the transmission data rate, for example, the audio signal can be encoded using low-delay compression coding technology, which can reduce the transmission data rate by more than 4 times. Second, increase the air interface transmission rate, such as working at a higher MCS (Modulation and Coding Scheme) rate configuration. Third, reduce the duration of the receiving time slot. For example, since some control instructions sent by the audio and video transmission device 11 to the wireless microphone transmitting device 12 usually do not have high requirements for real-time performance, when the wireless microphone transmitting device 12 is in a dormant state, the audio and video transmission device 11 can cache these control instructions first, wait for the wireless microphone transmitting device 12 to be awakened, and then send them to the wireless microphone transmitting device 12. This can also reduce the receiving time slot time of the wireless microphone transmitting device 12 and achieve the purpose of saving power. For example, the WIFI transmission unit of the audio and video transmission device 11 can adopt the downlink data packet caching technology in the WMM QOS power saving mechanism. The audio and video transmission device 11 can send the control instruction (i.e., downlink data packet) sent to the wireless microphone 13 in a triggering manner. When the audio and video transmission device 11 does not receive the trigger frame sent by the wireless microphone transmitting device 12, the control instruction will be cached. When the trigger frame is received, it means that the wireless microphone transmitting device 12 is in the awake state at this time, and the control instruction can be sent to the wireless microphone transmitting device 12 at this time.

[0052] In general, in order to reduce power consumption as much as possible, the wireless microphone transmitting device 12 can continuously switch between working states such as transmitting-receiving-sleeping-awakening. It can be seen that the wireless microphone transmitting device 12 has the characteristic of being awakened periodically. Since the real-time requirements of the audio signal are higher, the wireless microphone transmitting device 12 can immediately send the audio signal to the audio and video transmission device 11 after waking up. As for the control instructions sent by the audio and video transmission device 11, since the data volume is small and the real-time requirements are not high, when the wireless microphone transmitting device 12 is dormant, the audio and video transmission device 11 can cache the control signal and send it in batches after the wireless microphone transmitting device 12 is awakened. After waking up, the wireless microphone transmitting device 12 will first send the audio signal and then receive the control instruction sent by the audio and video transmission device 11. In this way, the power consumption of the wireless microphone transmitting device 12 can be greatly reduced.

[0053] In some embodiments, in order to further reduce the power consumption of the wireless microphone transmitting device 12, the WIFI transmission unit of the wireless microphone transmitting device 12 is configured as a single-transmit single-receive mode (SISO: single input single out mode), and a single antenna can be used to send and receive data to reduce the number of antenna transmitting and receiving channels, thereby achieving the purpose of saving power consumption.

[0054] In order to further explain the audio and video transmission device and the audio and video transmission system provided in the embodiments of this specification, a specific embodiment is described below.

[0055] In film and television shooting and commercial video shooting scenes, the photographer usually uses a camera to collect the video of the subject, and then sends it to the director and other staff through wireless transmission technology to remotely monitor the shooting effect. During the shooting process, the video signal and audio signal of the subject can be collected at the same time. Usually, the camera has a built-in microphone to receive the audio signal of the subject. However, when the subject is far away from the camera, the sound reception effect of the built-in microphone is poor, which seriously affects the final audio and video effect.

[0056] The embodiments of this specification provide an audio and video transmission system, which can effectively solve the problem of collecting and transmitting audio signals in shooting scenes where the distance between the object being photographed and the camera device is far. Fig. 9As shown, the audio and video transmission system includes a wireless microphone 91, wherein the number of wireless microphones 91 is not limited, and two are taken as an example in the figure. An audio and video transmission device 92 and a wireless video receiving terminal 93, wherein the number of wireless video receiving terminals 93 is also not limited, and the wireless video receiving terminal can be an intelligent terminal with a general WIFI connection function and a general H.264 / H.265 video decoding capability, or an independent device with a stronger hardware H.264 / H.265 decoding capability and a stronger wireless WIFI performance, and the independent device can be connected to a switch or a monitoring station 94. The wireless microphone 91 can adopt an integrated design of a microphone body and a wireless microphone transmitting device in the above embodiment, for example, it can be designed into a miniature collar clip mode and carried by the subject, so that the microphone body can reduce the interference of external noise, clearly collect the audio signal of the subject, improve the effect of the collected audio signal, and send it to the audio and video transmission device 92 through the wireless microphone transmitting device.

[0057] The audio and video transmission device 92 can be installed on the camera device 95 and connected to the camera device 95 through a physical interface. The audio and video transmission device 92 is used to receive the audio signal sent by the wireless microphone 91, and input it to the camera device 95 through the physical interface. The camera device 95 synchronizes and aligns the audio signal and the collected video signal to generate a mixed signal after the audio and video signals are mixed, and outputs the mixed signal to the audio and video transmission device 92. The audio and video transmission device 92 sends the mixed signal to the wireless video receiving terminal 93 so that the director and other staff can view the captured audio and video. Among them, the wireless video receiving terminal 93 can be a device with an APP installed, such as a mobile phone, a tablet, a laptop computer or an independent hardware device, etc. The APP can receive the audio and video signals of the camera device 95 from the audio and video transmission device 92.

[0058] The audio signal and the mixed signal can adopt WIFI transmission technology, for example, WIFI IEEE 802.11 transmission technology can be uniformly adopted, and the WIFI transmission unit for transmitting the audio signal and the mixed signal can operate in 2.4 GHz, 5 GHz UNII or 60 GHz ISM frequency band. The networking mode in the transmission process is that the audio and video transmission device 92 operates in AP mode, and the wireless microphone 91 and the wireless video receiving terminal 93 operate in Station mode.

[0059] In order to save wireless channel resources and reduce mutual interference between the audio signal and the mixed signal during transmission, the audio signal and the mixed signal can be transmitted using the same wireless channel in a time division multiplexing manner.

[0060] The structures and processing procedures of the wireless microphone 91, the audio and video transmission device 92, and the wireless video receiving end 93 are respectively introduced in detail below.

[0061] 1. Wireless microphone

[0062] The following is a schematic diagram of the structure of the wireless microphone 91 Fig.10 To introduce its processing flow.

[0063] The wireless microphone 91 includes a microphone audio drive amplifier circuit 912, which is connected to the microphone body (910 or 911) and is mainly used for analog audio signal generation and audio signal adjustment. The wireless microphone 91 supports the input of the built-in microphone body 910 and the external microphone body 911. When the built-in microphone 910 and the external microphone body 911 are connected at the same time, the external microphone body 911 can be preferentially selected as the main signal input through impedance change detection of the external microphone body 911 or through digital signal detection of the multi-channel audio sampling ADC (Analog to Digital Converter: analog-to-digital converter) 913. When no external microphone body 911 is connected, the system defaults to the built-in microphone body 910 as the audio input signal input.

[0064] After the audio driving amplifier circuit 912 generates an audio analog signal, it is input to the multi-channel audio sampling ADC913. The multi-channel audio sampling ADC913 converts the analog audio signal into a digital original audio signal, and has pre-amplification gain adjustment and digital level gain adjustment functions. The CPU915 can adjust the input volume of the microphone body by controlling the adjustment of the pre-amplification gain or the digital level gain.

[0065] The multi-channel audio sampling ADC 913 sends the digital original audio signal to the audio signal processing and compression coding DSP unit 914, which implements low-delay and low-loss compression coding of the audio signal and implements audio signal enhancement processing functions such as equalization and noise reduction. In order to reduce the transmission delay of the audio signal, the audio signal adopts a low-delay and low-loss compression technology, such as one of OPUS-CELT, ADPCM, LC3, and LC3plus compression coding technologies.

[0066] The audio signal processing and compression coding DSP unit 914 sends the coded and compressed digital audio signal to the CPU 915. The CPU 915 runs the TCP / IP protocol stack to complete the conversion from the digital compressed audio signal to the IP data stream, the wireless transmission parameter configuration management, and the audio parameter configuration. At the same time, the CPU 915 can also realize the control and management functions of the buttons / LCD screen, power supply and other accessories 917. The main control work is completed by the built-in firmware.

[0067] CPU 915 transmits the audio signal to WIFI transmission unit 916, and WIFI transmission unit 916 transmits the audio signal to audio and video transmission device 92 via antenna 918. WIFI transmission unit 916 works in Station mode and maintains wireless communication connection with audio and video transmission device 92 working in AP mode, mainly completing WIFI wireless transmission protocol stack and wireless transmission link functions, and can work alternately in send-receive-sleep-wake mode, and can support WIFI WMM QOS mechanism and WMM power saving function.

[0068] In addition, the wireless microphone 91 also includes other accessories 917, such as buttons, LCD screen, power supply, casing and installation accessories.

[0069] 2. Audio and video transmission device

[0070] The following is a schematic diagram of the structure of the audio and video transmission device 92 Fig.11 To introduce its workflow.

[0071] The audio and video transmission device 92 includes an interface circuit part, which mainly includes an SDI video receiver 920, an HDMI video receiver 921, a CCU control signal interface circuit 922 and a multi-channel audio amplifier processor 923.

[0072] The interface part of the camera device 95 includes an SDI video interface 950, an HDMI video interface 951, a CCU control interface 952 and an external microphone audio interface 953. The camera device 95 outputs SDI and HDMI standard video interface signals through the SDI video interface 950 and the HDMI video interface 951, and converts them into standard digital parallel video signals through the SDI video receiver 920 and the HDMI video receiver 921. The signal format is BT1120 or MIPI, and is sent to the back-end FPGA chip 924. The FPGA chip 924 mainly processes the video signal and selects the bus. The FPGA chip 924 selects the required video and sends it to the system SOC chip 925. The system SOC chip 925 can be a chip that integrates CPU and H.264 / H.265 encoding and decoding functions. The SOC chip 925 compresses and encodes the video. The digital serial video interface signal also includes a dual-channel digital accompanying audio signal, which can be directly sent to the system SOC chip 925 and separately from the video signal for audio compression processing.

[0073] The SOC chip 925 is connected to the WIFI transmission unit 926, and sends the compressed mixed signal to the WIFI transmission unit 926, so that the WIFI transmission unit 926 sends it to the wireless video receiving end 93 through the antenna 9210. At the same time, the WIFI transmission unit 926 receives the audio signal sent by the wireless microphone 91 and transmits it to the SOC chip 925. The WIFI transmission unit 926 of the audio and video transmission device 92 works in AP mode, can set an independent SSID, can connect multiple wireless microphones 91 and wireless video receiving ends 93, and form a BSS (Basic Service Set) network system unit. The WIFI transmission unit 926 supports the WIFI WMM protocol, supports the WMM QOS mechanism and the WMM power saving function.

[0074] After receiving the audio signal collected by the wireless microphone sent by the WIFI transmission unit 926, the SOC chip 925 can convert it into a digital compressed audio signal. The format of the compressed audio signal is the same as the audio signal format sent by the wireless microphone, which is a type of audio signal encoded by ADPCM, Opus-CELT, LC3, and LC3plus low-delay and low-loss audio compression coding algorithms. The SOC chip 925 sends the digital compressed audio signal to the audio signal processing and compression decoding DSP unit 927. The audio signal processing and compression decoding DSP unit 927 completes the decoding and output of the digital compressed audio, and can also complete the processing functions of equalization, sound effects, noise reduction, and volume level adjustment. The audio signal recovered after decoding can be a 48KHz 16-24bit high-definition audio signal, and then the conversion from digital audio to analog audio is completed through the multi-channel audio sampling DAC928. The converted analog audio is processed by the multi-channel audio amplifier processor 923, and the output amplitude meets the analog audio signal level requirement of the external microphone audio interface 953 of the camera device 95.

[0075] In addition, the SOC chip 925 is also connected to the camera device CCU control interface 953 through the CCU control interface circuit 923, and can support the control of the CCU of the camera device 951.

[0076] The SOC chip 925 is also connected to the accessory 929 through the expansion interface to realize the control of the accessory. The accessory 929 includes a button, an LCD screen, a power supply, a housing, and installation accessories.

[0077] 3. Wireless video receiver

[0078] The wireless video receiving end 93 can be a smart terminal with a general WIFI connection function and a general H.264 / H.265 video decoding capability, or it can be an independent device with stronger hardware H.264 / H.265 decoding capability and stronger wireless WIFI performance. If the wireless video receiving end is an independent device, its structural diagram is as follows: Fig.12 As shown, the following describes its workflow in conjunction with its structural diagram.

[0079] The wireless video receiving end 93 includes a WIFI transmission unit 931, which receives the mixed signal sent by the audio and video transmission device 92 through the antenna 930. The WIFI transmission unit 931 works in the Station mode and maintains a wireless communication connection with the audio and video transmission device 92 working in the AP mode, and receives the mixed signal of the audio and video sent by the audio and video transmission device 92.

[0080] After receiving the mixed signal, the WIFI transmission unit 931 sends it to the system SOC chip 932. The system SOC chip 932 can be a chip integrating CPU and H.264 / H.265 encoding and decoding functions. The SOC chip 932 completes the compression and decoding of the video signal in the mixed signal, and completes the decoding of the audio signal at the same time. Then the SOC chip 932 directly sends the audio signal in the mixed signal to the SDI transmitter 934 and the HDMI transmitter 935, and outputs the video signal in the mixed signal to the FPGA chip 933. The format of the video signal is BT1120 or MIPI. The FPGA chip 933 is mainly used to process the video signal in the mixed signal and distribute it on the bus. The FPGA chip 933 completes functions such as digital video signal format conversion, image enhancement, auxiliary data and parallel video bus distribution, and then sends the video signal to the SDI transmitter 934 and the HDMI transmitter 935. The SDI transmitter 934 and the HDMI transmitter 935 transmit the audio signal and the video signal to the monitor or the video switch 94 through the SDI video interface 940 and the HDMI video interface 941 of the monitor or the video switch 94 connected to the wireless video receiving terminal 93.

[0081] The wireless video receiving terminal 93 also includes accessories 936, which are connected to the system SOC chip 932 and controlled by the SOC chip 932. The accessories include buttons, an LCD screen, a power supply, a housing, and installation accessories.

[0082] The audio and video transmission system provided in the embodiments of this specification reduces the transmission delay of the audio signal by adopting low-delay coding compression for the audio signal, setting the priority of audio signal transmission higher than the priority of mixed signal, and adopting a short frame structure for the audio signal. Through the above technology, the delay of the audio signal is as follows:

[0083] T0 is the low-latency audio signal compression encoding delay, which is less than 0.5ms.

[0084] T1 is the buffer delay before the audio signal data frame is encoded, which is related to the data frame length and has a minimum value of 2.5ms.

[0085] T2 is the delay in sending and receiving audio signals during transmission, which is less than 1ms.

[0086] T3 is the length of the air interface transmission time slot, which is less than 0.5ms.

[0087] T4 is the audio signal decoding delay, which is less than 0.5ms.

[0088] The final total transmission delay of the audio signal is T0+T1+T2+T3+T4, which can basically achieve the goal of <5ms.

[0089] In addition, the audio and video transmission system provided in the embodiment of this specification can greatly reduce the power consumption of the wireless microphone 91 by adopting low-delay compression coding technology for audio signals, single-transmit and single-receive mode for wireless microphone 91, transmit-receive-sleep-wake working mode for WIFI transmission unit of wireless microphone, and cache control instructions sent to wireless microphone 91 by audio and video transmission device 92, and send them collectively when it is in wake-up state. When the WIFI transmission unit of wireless microphone 91 is in sleep state, its power consumption current can be as low as about 20uA, and the current gradually increases in wake-up state, and the maximum transmission time slot current can reach 200mA, and then it enters the receiving state, and the current drops to 80mA, and its power consumption is significantly reduced.

[0090] It can be seen from the above description that the audio and video transmission system provided in this embodiment can have the following advantages:

[0091] (1) The audio signal of the subject is collected by the wireless microphone 91 which is physically separated from the camera device 94. Compared with the microphone built into the camera device, the quality of the audio signal can be improved. In addition, the audio signal and the mixed signal can be transmitted simultaneously through the audio and video transmission device 92, which is convenient for installation.

[0092] (2) Both the audio signal and the mixed signal can adopt wireless transmission technology. The audio and video transmission device 92 uses the same wireless transmission channel to transmit the audio signal and the mixed signal in a time-division multiplexing manner, saving channel resources and avoiding interference between the two signal transmissions. This transmission scheme can take into account the characteristics of the audio signal collected by the wireless microphone, such as small bandwidth occupation, low power consumption, and low delay parameters, while ensuring the high transmission bandwidth requirements of the wireless video signal, so that the audio and video transmission services can each take what they need.

[0093] (3) Since audio signals have higher real-time requirements, the WMM QOS mechanism can be used to set the transmission priority of audio signals higher than that of mixed signals to reduce the delay of audio signals.

[0094] (4) Reduce the transmission delay of audio signals by performing low-delay and low-loss compression on audio signals.

[0095] (5) The audio signal can adopt a short frame structure. The WIFI transmission unit of the wireless microphone 91 is configured as a single-transmit and single-receive mode. The wireless microphone transmitting device can continuously switch between multiple working modes of transmitting-receiving-sleeping-awakening. For audio signals with high real-time requirements, they can be transmitted immediately after waking up. For control instructions, the data volume is small and the real-time requirements are not high. When the wireless microphone 91 is dormant, it can be cached by the audio and video transmission device 92 and sent out after it wakes up. Through the above means, the power consumption of the wireless microphone 91 can be greatly reduced.

[0096] The various technical features in the above embodiments can be combined arbitrarily as long as there is no conflict or contradiction between the combinations of features. However, due to space limitations, they are not described one by one. Therefore, any combination of the various technical features in the above embodiments also falls within the scope of this specification.

[0097] Those skilled in the art will readily appreciate other implementations of the embodiments of the present specification after considering the specification and practicing the specifications disclosed herein. The embodiments of the present specification are intended to cover any variations, uses, or adaptations of the embodiments of the present specification, which follow the general principles of the embodiments of the present specification and include common knowledge or customary technical means in the art that are not disclosed in the embodiments of the present specification. The description and embodiments are to be considered merely as exemplary, and the true scope and spirit of the embodiments of the present specification are indicated by the claims below.

[0098] It should be understood that the embodiments of the present specification are not limited to the precise structures described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the embodiments of the present specification is limited only by the appended claims.

[0099] The above description is only a preferred embodiment of the embodiments of this specification and is not intended to limit the embodiments of this specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of this specification should be included in the scope of protection of the embodiments of this specification.

Claims

1. An audio and video transmission system, characterized in that: The system comprises an audio and video transmission device and at least one wireless microphone transmitting device, wherein the audio and video transmission device is respectively connected to the at least one wireless microphone transmitting device and to an external video acquisition device, wherein a physical interface is provided in the audio and video transmission device, and the audio and video transmission device is connected to the video acquisition device via the physical interface; The wireless microphone transmitting device is used to send the audio signal collected by the wireless microphone to the audio and video transmission device; The audio and video transmission device is used to receive the audio signal, transmit the audio signal to the video acquisition device, and obtain a mixed signal generated by the audio signal and the video signal from the video acquisition device, and output the mixed signal after processing; wherein the audio and video transmission device transmits the audio signal and the mixed signal through the same wireless channel in a time division multiplexing manner.

2. The audio and video transmission system according to claim 1, characterized in that: The audio and video transmission device transmits the audio signal and the mixed signal through the same wireless channel in a time division multiplexing manner.

3. The audio and video transmission system according to claim 2, characterized in that: The audio signal is transmitted with a higher priority than the mixed signal.

4. The audio and video transmission system according to claim 1, characterized in that: Before sending the audio signal to the audio and video transmission device, the wireless microphone transmitting device compresses the audio signal using a low-delay and low-loss compression technology, and the low-delay and low-loss compression technology includes one of OPUS-CELT, ADPCM, LC3, and LC3plus.

5. The audio and video transmission system according to claim 4, characterized in that: The frame length of the audio signal is configured to be smaller than a specified length.

6. The audio and video transmission system according to claim 1, characterized in that: The system also includes an APP installed on an external electronic device, and the mixed signal processed by the audio and video transmission device is sent to the APP, so that the APP decodes the processed mixed signal and displays it.

7. The audio and video transmission system according to claim 6, characterized in that: The wireless microphone transmitting device and the audio and video transmission device include a WIFI transmission unit. The audio and video transmission device is connected to the wireless microphone transmitting device and the external electronic device through a WIFI channel. The working mode of the audio and video transmission device is AP mode, and the working mode of the wireless microphone transmitting device and the electronic device is Station mode.

8. The audio and video transmission system according to claim 7, characterized in that: The working state of the WIFI transmission unit of the wireless microphone transmitting device switches alternately between a dormant state and a wake-up state.

9. The audio and video transmission system according to claim 8, characterized in that: The WIFI transmission unit of the wireless microphone transmitting device switches from a sleep state to a wake-up state at a preset time interval, and after completing the transmission task in this wake-up state, switches from the wake-up state to the sleep state; the transmission task includes sending the audio signal to the audio and video transmission device, and receiving control instructions from the audio and video transmission device.

10. The audio and video transmission system according to claim 9, characterized in that: The audio and video transmission device caches the control instruction when the working state of the WIFI transmission unit of the wireless microphone transmitting device is a dormant state.

11. The audio and video transmission system according to claim 7, characterized in that: The WIFI transmission unit of the wireless microphone transmitting device is configured in a single-transmit and single-receive mode.

12. An audio and video transmission device, characterized in that: The audio and video transmission device is connected to an external video acquisition device and a wireless microphone transmitting device respectively, wherein a physical interface is provided in the audio and video transmission device, and the audio and video transmission device is connected to the video acquisition device through the physical interface, and the audio and video transmission device comprises: An audio transmission unit, used to receive an audio signal collected by a wireless microphone from the wireless microphone transmitting device, and transmit the audio signal to the video collection device; A video transmission unit is used to obtain a mixed signal of the audio signal and the video signal from the video acquisition device and output the mixed signal; wherein the audio and video transmission device transmits the audio signal and the mixed signal through the same wireless channel in a time division multiplexing manner.

13. The audio and video transmission device according to claim 12, characterized in that: The audio and video transmission device transmits the audio signal and the mixed signal through the same wireless channel in a time division multiplexing manner.

14. The audio and video transmission device according to claim 13, characterized in that: The audio signal is transmitted with a higher priority than the mixed signal.

15. The audio and video transmission device according to claim 12, characterized in that: The audio signal is compressed by a low-delay and low-loss compression technology and then sent to the audio transmission unit. The low-delay and low-loss compression technology includes one of OPUS-CELT, ADPCM, LC3, and LC3plus.

16. The audio and video transmission device according to claim 15, characterized in that: The frame length of the compressed audio signal is smaller than the specified length.

17. The audio and video transmission device according to claim 12, characterized in that: The audio and video transmission device also includes a WIFI transmission unit, the audio transmission unit receives the audio signal from the wireless microphone transmitting device through the WIFI transmission unit, and the video transmission unit sends the mixed signal through the WIFI transmission unit.

18. The audio and video transmission device according to claim 17, characterized in that: The audio and video transmission device also includes a central processing unit, which is used to receive the audio signal in the mixed signal and the video signal in the mixed signal from the video transmission unit, compress and encode the audio signal in the mixed signal and the video signal in the mixed signal respectively, and output them to the WIFI transmission unit, and receive the audio signal sent by the wireless microphone transmitting device from the WIFI transmission unit, convert it into a digital compressed audio signal, and then send it to the audio transmission unit.

19. The audio and video transmission device according to claim 18, characterized in that: The audio transmission unit includes an audio processing subunit, a sampling subunit and a first interface subunit. The audio processing subunit is used to decode the digital compressed audio signal; The sampling subunit is used to perform sampling and recovery on the decoded digital compressed audio signal to obtain an analog audio signal; The first interface subunit is used to output the analog audio signal to the video acquisition device.

20. The audio and video transmission device according to claim 18, characterized in that: The video transmission unit includes a second interface subunit and a video signal processing subunit; The second interface subunit is used to receive the mixed signal from the video acquisition device, separate the audio signal from the mixed signal and the video signal from the mixed signal, transmit the audio signal from the mixed signal to the central processing unit, and transmit the video signal from the mixed signal to the video signal processing subunit; The video signal processing subunit is used for processing the video signal in the mixed signal and then sending it to the central processing unit for compression coding processing.

21. The audio and video transmission device according to claim 18, characterized in that: The audio and video transmission device also includes a CCU control interface, and the central processing unit controls the CCU of the video acquisition device through the CCU control interface.

22. The audio and video transmission device according to claim 18, characterized in that: The audio and video transmission device also includes an expansion interface connected to the central processing unit, which is used to connect one or more of the following accessories: an LCD screen, a button, and a power supply.

Images