Video acquisition circuit and law enforcement recorder

Abstract

The application provides a video acquisition circuit and a law enforcement recorder. The video acquisition circuit comprises an encoding chip, a switching circuit and a processing chip. The encoding chip is used for being connected with a camera module, receiving video data collected by the camera module and encoding the video data to obtain encoded video data. The switching circuit has a control end, a first end, a second end and a third end. The first end is connected with a memory card slot, and the second end is connected with the encoding chip. The processing chip is connected with the control end and the third end of the switching circuit respectively. When a memory card is detected to be inserted into the memory card slot, the processing chip controls the switching circuit to connect the first end and the second end, so that the encoded video data can be saved in the memory card. In the case of inserting the memory card, the processing chip controls the switching circuit to connect the memory card and the encoding chip. When recording the video, only the encoding chip consumes power, and the processing chip is in a low-power suspension state, so that the power consumption of the law enforcement recorder is reduced, and the circuit heating is reduced.

Description

Technical Field

[0001] This application relates to the field of video acquisition technology, and more specifically, to a video acquisition circuit and a law enforcement recorder. Background Technology

[0002] Law enforcement agencies need to use body cameras to capture video during law enforcement operations to record the entire process. With the improvement of network technology and the processing power of video encoding chips, the highly intensive data poses a huge challenge to bandwidth and storage. Most body cameras on the market use mobile phone chips produced by specific companies and use ARM for software compression encoding, resulting in high power consumption and serious heat generation. Summary of the Invention

[0003] The purpose of this application is to provide a video acquisition circuit and a law enforcement recorder to improve the above-mentioned technical problems.

[0004] In a first aspect, embodiments of this application provide a video acquisition circuit for use in a law enforcement recorder, the law enforcement recorder further including a camera module and a memory card slot, the circuit comprising:

[0005] An encoding chip is used to connect to the camera module, receive video data collected by the camera module, and encode it to obtain encoded video data;

[0006] A switching circuit has a control terminal, a first terminal, a second terminal, and a third terminal, used to selectively connect one of the second terminal and the third terminal to the first terminal, wherein the first terminal is connected to the memory card slot and the second terminal is connected to the encoding chip;

[0007] The processing chip is connected to the control terminal and the third terminal respectively, and is used to control the switching circuit to connect the first terminal and the second terminal when a memory card is detected inserted in the memory card slot, so that the encoded video data can be stored in the memory card.

[0008] In the circuit described above, when a memory card is inserted into the memory card slot, the processing chip controls the switching circuit to connect the memory card and the encoding chip. As a result, the video recorded by the camera module can be directly stored in the memory card after encoding. No other operations can be performed during the video recording process. At this time, the processing chip is in a low-power suspended state, that is, only the encoding chip consumes power when recording video. The power consumption of the encoding chip during operation is very low, thereby reducing the overall power consumption of the law enforcement recorder and reducing circuit heat generation.

[0009] In an optional implementation, the circuit further includes a network communication module connected to the processing chip. The processing chip is also used to control the switching circuit to connect the first terminal to the third terminal when it receives a video recording end signal, so that the processing chip can access the encoded video data in the memory card and upload the encoded video data to the backend server through the network communication module.

[0010] After recording ends, the processing chip controls the switching circuit to connect the memory card and the processing chip, allowing the processing chip to access and upload the encoded video data on the memory card. Through the switching circuit, the processing chip and the encoding chip can share the same memory card's storage resources.

[0011] In one optional embodiment, the processing chip includes a memory; the processing chip is connected to the encoding chip and is used to receive encoded video data sent by the encoding chip and store it in the memory when no memory card is detected inserted in the memory card slot.

[0012] The processing chip has a built-in memory of a certain capacity. For law enforcement recorders, they do not need to rely on memory cards. Even without a memory card inserted, the law enforcement recorder can still store encoded video data through the memory in the processing chip, meaning that the law enforcement recorder continues to work.

[0013] In one optional embodiment, the circuit further includes a brightness sensor and an infrared lamp, both of which are connected to the encoding chip; the brightness sensor is used to detect ambient brightness; and the encoding chip is used to control the infrared lamp to emit infrared light when the ambient brightness is lower than a preset value.

[0014] When recording video at night, the infrared lights are turned on, emitting infrared light to illuminate the object. The infrared light is diffusely reflected and received by the camera module to form video data, thus enabling the law enforcement recorder to have good night video acquisition capabilities.

[0015] In one optional embodiment, the circuit further includes a first isolation circuit; the first isolation circuit includes: a first resistor, a second resistor, a first capacitor, a first field-effect transistor (FET), and a first diode. A first terminal of the first resistor is connected to the enable control terminal of the encoding chip for receiving a power enable signal from the encoding chip. A second terminal of the first resistor is connected to the gate of the first FET. The source of the first FET is connected to the power output terminal of the encoding chip, the first terminal of the second resistor, and the first terminal of the first capacitor, respectively. The second terminal of the second resistor and the second terminal of the first capacitor are connected to the gate of the first FET. The drain of the first FET is connected to the anode of the first diode, and the cathode of the first diode is connected to the power input terminal of the memory card slot.

[0016] In one optional embodiment, the circuit further includes a second isolation circuit; the second isolation circuit includes a second diode and a second capacitor, the anode of the second diode is connected to the power output terminal of the processing chip, the cathode of the second diode and the first terminal of the second capacitor are connected to the power input terminal of the memory card slot, and the second terminal of the second capacitor is grounded.

[0017] In both of the above implementations, by setting a first diode, the power supply voltage of the processing chip is isolated by the first diode in the first isolation circuit and cannot reach the encoding chip; by setting a second diode, the power supply voltage of the encoding chip is isolated by the second diode in the second isolation circuit and cannot reach the processing chip. Therefore, while ensuring power supply to the memory card, a good power isolation effect is achieved.

[0018] In one optional embodiment, the circuit further includes a battery unit and a power conversion unit. The battery unit is connected to the processing chip, and the power conversion unit is connected to both the battery unit and the encoding chip. The battery unit supplies power to the processing chip, and the power conversion unit converts the power supply voltage of the battery unit into the operating voltage of the encoding chip and supplies power to the encoding chip.

[0019] In one optional implementation, the circuit further includes a button assembly connected to the processing chip, used to control the camera module to acquire or stop acquiring the video data.

[0020] In one alternative implementation, the encoding chip uses the H.265 encoding standard to encode the video data.

[0021] In the above scheme, the use of H.265 encoding technology can save half the storage space compared to H.264 encoding technology at the same image quality. This is beneficial for storing videos for a longer period of time with the same storage capacity. As a result, the weekly backup cycle of the acquisition station can be extended to several months. Moreover, the hardware expenses of storage devices can be reduced by several times.

[0022] Secondly, embodiments of this application provide a law enforcement recorder, including: an instrument housing; a camera module; a memory card slot for inserting a memory card; and a video acquisition circuit as described in the first aspect, disposed within the instrument housing. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the video acquisition circuit provided in an embodiment of this application;

[0025] Figure 2 This is a specific circuit diagram of the camera module in an embodiment of this application;

[0026] Figure 3 This is a specific circuit diagram of the switching circuit in an embodiment of this application;

[0027] Figure 4 Another schematic diagram of the video acquisition circuit provided in the embodiments of this application;

[0028] Figure 5 A circuit diagram of the first isolation circuit provided in the embodiments of this application;

[0029] Figure 6 A circuit diagram of the second isolation circuit provided in an embodiment of this application.

[0030] Icons: 110 - Encoding chip; 120 - Switching circuit; 130 - Processing chip; 140 - Camera module; 150 - Memory card slot; 160 - Brightness sensor; 170 - Infrared light; 180 - Button assembly. Detailed Implementation

[0031] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0032] This application provides a video acquisition circuit for use in a law enforcement recorder, which also includes a camera module and a memory card slot. Figure 1 A schematic diagram of the video acquisition circuit is shown. The circuit includes an encoding chip 110, a switching circuit 120, and a processing chip 130. The encoding chip 110 is connected to the camera module 140 and is used to receive and encode the video data acquired by the camera module 140 to obtain encoded video data. The switching circuit 120 has a control terminal, a first terminal, a second terminal, and a third terminal. The switching circuit 120 is used to selectively connect one of the second terminal and the third terminal to the first terminal. The first terminal is connected to the memory card slot 150, and the second terminal is connected to the encoding chip 110. The processing chip 130 is connected to the control terminal and the third terminal of the switching circuit 120, respectively. When a memory card is detected inserted in the memory card slot 150, the processing chip 130 controls the switching circuit 120 to connect the first terminal and the second terminal, so that the encoded video data can be stored in the memory card.

[0033] When the law enforcement recorder is powered on, the processing chip 130 detects whether a memory card is inserted in the memory card slot 150. If a memory card is inserted, it sends a first control level signal (e.g., a high level signal) to the control terminal of the switching circuit 120. After receiving the first control level signal, the control terminal of the switching circuit 120 connects the first terminal and the second terminal, so that the data channel of the memory card is connected to the encoding chip 110. After the video acquisition is started, the encoding chip 110 receives the video data acquired by the camera module 140 in real time and encodes it. The encoded video data is stored in the memory card.

[0034] Furthermore, the processing chip 130 can also send a second control level signal (e.g., a low-level signal) to the control terminal of the switching circuit 120. Upon receiving this second control level signal, the control terminal of the switching circuit 120 connects the first and third terminals of the switching circuit 120, enabling the data channel of the memory card to connect with the processing chip 130. Thus, the processing chip 130 can access the memory card and obtain the encoded video data therein. Based on this embodiment, the video acquisition circuit also includes a network communication module. The network communication module is connected to the processing chip and communicates with the backend server. The network communication module can be a part of the processing chip or independent of it. The processing chip receives a recording end signal and sends a second control level signal to the control terminal of the switching circuit, connecting the first and third terminals of the switching circuit. The processing chip then accesses the encoded video data in the memory card and uploads the encoded video data to the backend server via the network communication module.

[0035] Figure 2 A specific circuit diagram of a camera module according to an embodiment of this application is shown. For example... Figure 2As shown, pins A3 to A6 on the left side of chip U1201 in the camera module are connected to the encoding chip and are used to read the camera module address and transmit the start and stop signals for video acquisition, thereby controlling the camera module. Pins D2 to D5, C4, and E5 on the left side of chip U1201 are connected to the encoding chip and are used to transmit the acquired video data to the encoding chip. The power input terminal on the right side of chip U1201 is connected to the processing chip. Specifically, the processing chip supplies power to the camera module through pins VCAMIO_PMU, VCAMA_PMU, and VCAMD_PMU.

[0036] Figure 3 A specific circuit diagram of the switching circuit in an embodiment of this application is shown. For example... Figure 3 As shown, the switching circuit includes a switching chip U1401. Pins COM1 to COM6 of the switching chip U1401 are the first terminals. COM1 to COM4 are connected to the data pins (TF_DAT0 to TF_DAT3) on the memory card slot, respectively. COM5 is connected to the command and response multiplexing pin (TF_CMD) on the memory card slot, and COM6 is connected to the clock pin (TF_CLK) on the memory card slot. Pins NC1 to NC6 of the switching chip U1401 are the third terminals. NC1 to NC4 are connected to the data pins (MSDC1_DAT0 to MSDC1_DAT3) on the processing chip, respectively. NC5 is connected to the command and response multiplexing pin (MSDC1_CMD) on the processing chip, and NC6 is connected to the clock pin (MSDC1_CLK) on the processing chip. Pins NO1-NO6 of the switching chip U1401 are the second terminals. NO1-NO4 are connected to the data pins (SDIO0_DAT0-SDIO0_DAT3) on the encoding chip, NO5 is connected to the command and response multiplexing pin (SDIO0_CMD) on the encoding chip, and NO6 is connected to the clock pin (SDIO0_CLK) on the encoding chip. Pins IN1 and IN2 of the switching chip U1401 are control terminals used to connect to the processing chip. The power supply terminal (VCC) of the switching chip is connected to the battery cell (VBAT) for power.

[0037] The working principle of the switching circuit is as follows:

[0038] In its default state, the switching chip connects COM1 to NC1, COM2 to NC2, COM3 to NC3, COM4 to NC4, COM5 to NC5, and COM6 to NC6, meaning the memory card slot is connected to the processing chip. When the processing chip detects a memory card inserted in the memory card slot, GPIO152_TF_SW goes high. Under this high-level signal, the switching chip connects COM1 to NO1, COM2 to NO2, COM3 to NO3, COM4 to NO4, COM5 to NO5, and COM6 to NO6, meaning the memory card slot is connected to the encoding chip. After video acquisition ends, GPIO152_TF_SW goes low. Under this low-level signal, the switching chip switches back to connecting COM1 to NC1, COM2 to NC2, COM3 to NC3, COM4 to NC4, COM5 to NC5, and COM6 to NC6.

[0039] Optionally, the processing chip includes a memory and is connected to the encoding chip (e.g., via a USB interface or other data communication bus) to receive encoded video data sent by the encoding chip and store it in the memory when no memory card is detected in the memory card slot.

[0040] In this embodiment, when no memory card is inserted in the memory card slot of the law enforcement recorder, the encoding chip acquires the video data collected by the camera module, encodes it to obtain encoded video data, and sends the encoded video data to the connected processing chip. The processing chip stores the encoded video data in its internal memory. Therefore, the law enforcement recorder does not need to rely on a memory card and can still operate even without a memory card inserted.

[0041] In one embodiment, the processing chip can be a mobile phone chip, running an operating system (such as Android or other operating systems), and possessing a certain amount of RAM and a large storage capacity, such as 2GB of RAM and 16GB of storage. Through its operating system, the law enforcement recorder's touch and user interface resemble a mobile phone interface. The recorder can be equipped with multiple button components, such as a power button, a recording button, an SOS button, and volume control buttons, allowing users to quickly select and configure settings. This makes the recorder easy for staff to use and has a low barrier to entry. Specifically, the processing chip can be any model of mobile phone chip manufactured by companies such as MediaTek and Qualcomm.

[0042] Optional, such as Figure 4As shown, the video acquisition circuit also includes a brightness sensor 160 and an infrared lamp 170, both of which are connected to the encoding chip 110. The brightness sensor 160 is used to detect ambient brightness. The encoding chip 110 is used to control the infrared lamp 170 to emit infrared light when the ambient brightness is lower than a preset value.

[0043] A brightness sensor detects ambient light, converts the light signal into an electrical signal, and transmits the electrical signal to an encoding chip. The encoding chip then determines whether to turn on the infrared light based on this signal. During daytime video recording, the infrared light does not need to be turned on. At night, when recording video, the infrared light is turned on, emitting infrared light that illuminates objects. This diffuse reflection of the infrared light is then received by the camera module, forming video data, thus enabling the law enforcement recorder to have excellent nighttime video capture capabilities.

[0044] exist Figure 4 The video acquisition circuit also includes a button assembly 180, which is connected to the processing chip 130 and used to control the camera module to acquire or stop acquiring video data. This button assembly is a recording button. When the button assembly is pressed, the processing chip receives the electrical signal from the button assembly, generates a video acquisition start signal, and transmits the start signal to the encoding chip. The encoding chip then transmits the start signal to the camera module, causing the camera module to start video acquisition. When the button assembly is pressed again (or released), the processing chip receives the electrical signal from the button assembly (i.e., the previously mentioned video recording end signal), generates a video acquisition stop signal, and transmits the stop signal to the encoding chip. The encoding chip then transmits the stop signal to the camera module, causing the camera module to stop video acquisition. Simultaneously, the processing chip sends a second control level signal to the control terminal of the switching circuit, connecting the first and third terminals of the switching circuit.

[0045] In addition to the aforementioned button components, the video acquisition circuit includes other button components such as a power button, an SOS button, and volume control buttons. These buttons are connected to the processing chip. Furthermore, the processing chip is also connected to a display screen that shows the system interface, allowing staff to configure the body camera and display the video currently being captured by the camera module or playback of videos stored on the memory card. This display screen can be a touchscreen, providing both display and touch functionality, allowing staff to set the body camera's parameters via icons or options on the touchscreen. Alternatively, the display screen can be non-touchscreen, with the processing chip connected to a separate touch device for parameter settings.

[0046] In this embodiment, the processing chip is powered by a battery unit and is connected to the battery unit. The power supply voltage requirements for the encoding chip and other components are lower than those for the processing chip. Therefore, the video acquisition circuit also includes a first power conversion unit and a second power conversion unit. The first power conversion unit is connected to both the battery unit and the encoding chip, converting the battery unit's power supply voltage to the encoding chip's operating voltage and supplying power to the encoding chip. For example, the first power conversion unit converts the battery unit's 4V voltage to 3.3V. The second power conversion unit is connected to both the battery unit and the infrared lamp, converting the battery unit's power supply voltage to the infrared lamp's operating voltage and supplying power to the infrared lamp.

[0047] Furthermore, since the memory card slot can selectively connect to either the encoding chip or the processing chip, in this embodiment, the power supply to the memory card can also be switched between the encoding chip and the processing chip. For example, when the memory card slot is connected to the encoding chip, the memory card is powered by the encoding chip; when the memory card slot is connected to the processing chip, the memory card is powered by the processing chip. To prevent the power supply voltage of the encoding chip from reaching the processing chip and vice versa during operation, which could cause system leakage and chip damage, this embodiment provides a first isolation circuit and a second isolation circuit.

[0048] Among them, such as Figure 5 As shown, the first isolation circuit includes: a first resistor R1408, a second resistor R1407, a first capacitor C1404, a first field-effect transistor Q1401, and a first diode D1803. The first terminal of the first resistor R1408 is connected to the enable control terminal of the encoding chip. The enable control terminal (SDIO0_CARD_POWER_EN) of the encoding chip can output a power enable signal, and the first terminal of the first resistor R1408 is used to receive this power enable signal. The second terminal of the first resistor R1408 is connected to the first field-effect transistor Q1403. The gate of transistor Q1401 is connected to the power output terminal of the encoding chip, the first terminal of the second resistor R1407, and the first terminal of the first capacitor C1404. The second terminal of the second resistor R1407 and the second terminal of the first capacitor C1404 are connected to the gate of transistor Q1401. The drain of transistor Q1401 is connected to the anode of diode D1803. The cathode of diode D1803 is connected to the power input terminal of the memory card slot.

[0049] exist Figure 5In the example, the first resistor R1408 has a resistance of 100 ohms, the second resistor R1407 has a resistance of 47 kΩ, the first capacitor C1404 has a capacitance of 100 nanofarads, and the first field-effect transistor Q1401 is a P-channel field-effect transistor. These values ​​are merely examples; actual circuit designs are not limited to these. Furthermore, an N-channel field-effect transistor can also be used as the first field-effect transistor. Based on this device selection, the connection relationships of the components in the first isolation circuit need to be adjusted accordingly.

[0050] like Figure 6 As shown, the second isolation circuit includes a second diode D1804 and a second capacitor C1402. The anode of the second diode D1804 is connected to the power output terminal VMCH_PMU of the processing chip. The cathode of the second diode D1804 and the first terminal of the second capacitor C1402 are connected to the power input terminal VDD of the memory card slot J1402. The second terminal of the second capacitor C1402 is grounded. Figure 5 and Figure 6 In the first isolation circuit, the cathode of the first diode D1803 and the cathode of the second diode D1804 in the second isolation circuit are connected together to the power input terminal VDD of the memory card slot J1402.

[0051] exist Figure 6 In the example, the capacitance of the second capacitor C1402 is 4.7 microfarads. Of course, this value is just an example, and the circuit design in actual applications is not limited to this.

[0052] The working principles of the first isolation circuit and the second isolation circuit are as follows:

[0053] The enable control terminal (SDIO0_CARD_POWER_EN) of the encoding chip outputs a power enable signal. The level of this signal changes the gate voltage of the field-effect transistor, thereby controlling the conduction and cutoff between the source and drain. The first isolation circuit is enabled when the enable control terminal (SDIO0_CARD_POWER_EN) outputs a low level. When the enable control terminal outputs a low level, a low level is applied to the gate of the first field-effect transistor Q1401, forming a source-drain current. The 3.3V voltage output from the encoding chip's power output terminal reaches the power input terminal VDD of the memory card slot J1403 through the first field-effect transistor Q1401 and the first diode D1803, thus supplying power to the memory card.

[0054] The first isolation circuit is disabled when the enable control terminal SDIO0_CARD_POWER_EN outputs a high level. When the enable control terminal outputs a high level, a high level is applied to the gate of the first field-effect transistor Q1401, cutting off the connection between the source and drain. Therefore, the 3.3V voltage output from the encoder chip's power output terminal cannot power the memory card. At this time, the power output terminal VMCH_PMU of the processing chip in the second isolation circuit provides power to the memory card slot's power input terminal VDD through the second diode D1804, thereby powering the memory card.

[0055] Since both the first isolation circuit and the second isolation circuit are connected to the power input terminal of the memory card slot to supply power to the memory card, by setting the first diode and the second diode, the power supply voltage of the encoding chip is isolated by the second diode in the second isolation circuit and cannot reach the processing chip. At the same time, the power supply voltage of the processing chip is isolated by the first diode in the first isolation circuit and cannot reach the encoding chip, thus achieving a good power isolation effect while supplying power.

[0056] Furthermore, the encoding chip in this embodiment uses the H.265 encoding standard to encode video data. Most law enforcement recorders on the market use the H.264 encoding standard, which has a low compression rate. However, using H.265 audio and video encoding technology can save half the storage space compared to H.264 encoding technology at the same image quality. This allows for storing video for a longer period of time with the same storage capacity. As a result, the weekly backup cycle of the acquisition station can be extended to several months, and the hardware expenses of storage devices can also be reduced several times.

[0057] It should also be noted that the video acquisition circuit provided in this embodiment, through the setting of a switching circuit, automatically connects the memory card and the encoding chip after the processing chip is powered on. Therefore, the video recorded by the camera module can be directly stored in the memory card after encoding. During video recording, no other operations can be performed. At this time, the processing chip is in a low-power suspended state, requiring only 4-5 mA of current. That is, only the encoding chip consumes power during video recording, and this power consumption is very low, effectively reducing circuit heat generation. The entire law enforcement recorder operates in a low-power state. Furthermore, when not acquiring video, such as when viewing videos on the memory card, uploading videos to a backend server, or setting parameters, the encoding chip can be turned off, i.e., power to the encoding chip can be stopped, to further save power.

[0058] Furthermore, this application provides a law enforcement recorder, including: an instrument housing, a camera module, a memory card slot, and a video acquisition circuit. The camera module is used to acquire video data, the memory card slot is used to insert a memory card, and the video acquisition circuit is the circuit provided in the previous embodiment, which is disposed within the instrument housing. The video acquisition circuit includes an encoding chip, a switching circuit, and a processing chip. The camera module is connected to the encoding chip in the video acquisition circuit, and the memory card slot is connected to the switching circuit in the video acquisition circuit. The switching circuit can selectively connect the memory card slot to the processing chip, or connect the memory card slot to the encoding chip.

[0059] Optionally, the video acquisition circuit includes multiple button components connected to the processing chip, and these button components are located on the surface of the instrument housing.

[0060] It is understood that the video acquisition circuit provided in the previous embodiment is used in the law enforcement recorder. Therefore, the law enforcement recorder can have the same technical effect as the video acquisition circuit, which will not be elaborated here. The law enforcement recorder can be implemented with reference to the video acquisition circuit in the previous embodiment.

[0061] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0062] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A video capture circuit, comprising: Used in a law enforcement recorder, the law enforcement recorder also includes a camera module and a memory card slot, and the video acquisition circuit includes: An encoding chip is used to connect to the camera module, receive video data collected by the camera module, and encode it to obtain encoded video data; A switching circuit has a control terminal, a first terminal, a second terminal, and a third terminal, used to selectively connect one of the second terminal and the third terminal to the first terminal, wherein the first terminal is connected to the memory card slot and the second terminal is connected to the encoding chip; A processing chip, which is connected to the control terminal and the third terminal respectively, is used to control the switching circuit to connect the first terminal and the second terminal when a memory card is detected inserted in the memory card slot, so that the encoded video data is stored in the memory card; When a memory card is inserted into the memory card slot, the processing chip controls the switching circuit to connect the memory card and the encoding chip. As a result, the video recorded by the camera module is directly stored in the memory card after being encoded. The processing chip can not perform any other operations during the video recording process. At this time, the processing chip is in a low-power suspension state. That is, when recording video, only the encoding chip consumes power, and the power consumption of the encoding chip is low, thereby reducing the overall power consumption of the law enforcement recorder. The video acquisition circuit also includes a network communication module, which is connected to the processing chip. The processing chip is also used to control the switching circuit to connect the first terminal and the third terminal when it receives the end-of-video signal, so that the processing chip can access the encoded video data in the memory card and upload the encoded video data to the background server through the network communication module. After the recording ends, the processing chip controls the switching circuit to connect the memory card and the processing chip, enabling the processing chip to access and upload the encoded video data in the memory card; through the switching circuit, the processing chip and the encoding chip share the storage resources of the same memory card; The processing chip includes a memory; the processing chip is connected to the encoding chip and is used to receive encoded video data sent by the encoding chip and store it in the memory when no memory card is detected inserted in the memory card slot; For law enforcement recorders, they do not need to rely on memory cards. Even without a memory card inserted, the law enforcement recorder can still store encoded video data through the memory inside the processing chip, meaning that the law enforcement recorder continues to work. The video acquisition circuit also includes a brightness sensor and an infrared lamp, both of which are connected to the encoding chip. The brightness sensor is used to detect ambient brightness. The encoding chip is used to control the infrared lamp to emit infrared light when the ambient brightness is lower than a preset value. When shooting video at night, the infrared light is turned on, and the infrared light emits infrared light to illuminate the object. The infrared light is diffusely reflected and received by the camera module to form video data, thus enabling the law enforcement recorder to have the ability to collect video at night. The video acquisition circuit further includes a first isolation circuit; the first isolation circuit includes: a first resistor, a second resistor, a first capacitor, a first field-effect transistor, and a first diode. The first end of the first resistor is connected to the enable control terminal of the encoding chip for receiving the power enable signal of the encoding chip. The second end of the first resistor is connected to the gate of the first field-effect transistor. The source of the first field-effect transistor is connected to the power output terminal of the encoding chip, the first end of the second resistor, and the first end of the first capacitor, respectively. The second end of the second resistor and the second end of the first capacitor are connected to the gate of the first field-effect transistor. The drain of the first field-effect transistor is connected to the anode of the first diode. The cathode of the first diode is connected to the power input terminal of the memory card slot. The video acquisition circuit further includes a second isolation circuit; the second isolation circuit includes a second diode and a second capacitor, the anode of the second diode is connected to the power output terminal of the processing chip, the cathode of the second diode and the first terminal of the second capacitor are connected to the power input terminal of the memory card slot, and the second terminal of the second capacitor is grounded; By setting the first diode, the power supply voltage of the processing chip is isolated by the first diode in the first isolation circuit, preventing it from reaching the encoding chip; by setting the second diode, the power supply voltage of the encoding chip is isolated by the second diode in the second isolation circuit, preventing it from reaching the processing chip. Therefore, while ensuring power supply to the memory card, a power isolation effect is achieved. The video acquisition circuit further includes a battery unit and a power conversion unit. The battery unit is connected to the processing chip, and the power conversion unit is connected to both the battery unit and the encoding chip. The battery unit supplies power to the processing chip, and the power conversion unit converts the power supply voltage of the battery unit into the operating voltage of the encoding chip and supplies power to the encoding chip. The video acquisition circuit also includes a button assembly, which is connected to the processing chip and is used to control the camera module to acquire or stop acquiring the video data. The encoding chip uses the H.265 encoding standard to encode the video data.

2. A body camera, comprising: include: Instrument casing; Camera module; Memory card slot for inserting a memory card; The video acquisition circuit as described in claim 1 is disposed within the housing of the instrument.

Images