A real-time high-definition synchronous recording and playing terminal

Abstract

The utility model relates to audio and video recording equipment technical field, and disclose a kind of real-time high-definition synchronous audio and video recording terminal, including main power supply, shell, camera module, recording module and main control board, main control board is integrated with rubidium atomic clock chip, the clock output end of rubidium atomic clock chip is connected the image sensor clock input end of camera module and the ADC clock input end of recording module by coaxial shielded cable;SRAM frame buffer area is provided in main control board.The utility model is integrated with rubidium atomic clock chip by main control board, clock signal is directly connected the image sensor clock end of camera module and the ADC clock end of recording module by coaxial shielded cable, eliminate software time service path, and SRAM frame buffer area stores audio and video frame according to atomic clock timestamp physical stacking, realize hardware level timing alignment;Make audio-visual synchronization error greatly reduce, eliminate lip sync problem.

Description

Technical Field

[0001] This utility model belongs to the technical field of audio and video recording equipment, and specifically relates to a real-time high-definition synchronous audio and video recording terminal. Background Technology

[0002] A synchronous audio and video recording terminal is a device specifically designed for judicial scenarios, interviews, and other similar situations. It is used to achieve synchronous acquisition, recording, and storage of audio and video signals during interviews and other processes, and to ensure the integrity, tamper-proofness, and security of the data.

[0003] Currently, Chinese utility model patent CN204968007U discloses an embedded and ARM platform hybrid synchronous audio and video recording device. This device includes an embedded acquisition module and a data transmission module for acquiring audio and video signals. The device also includes an ARM hardware platform and a fault detection module. The ARM hardware platform is communicatively connected to the embedded acquisition module, which includes a video acquisition module, an audio acquisition module, and a synchronous acquisition module. The synchronous acquisition module is electrically connected to the audio and video acquisition modules. The fault detection module is electrically connected to the embedded acquisition module and the ARM hardware platform, and is also wirelessly and / or wiredly connected to the data transmission module, which is connected to the embedded acquisition module. This utility model has the advantages of small size, low power consumption, and low cost, and can detect internal faults and achieve lip-sync.

[0004] In the aforementioned disclosed technologies, the use of main control chip software to coordinate the sampling timing of the camera and microphone can easily lead to uncontrollable cumulative errors, failing to meet the millisecond-level synchronization requirements for interviews, court recordings, etc., and relying on ARM platform software for time synchronization, the deviation rate increases significantly when used on multiple terminals.

[0005] Furthermore, the microphone array is directly soldered to the circuit board, and the vibration during device operation greatly increases the audio distortion rate, making vibration noise obvious. In addition, there is no filtering structure, making it difficult to meet the requirements for recording clarity.

[0006] Meanwhile, relying on the main control chip to monitor the power supply voltage and switch lithium batteries results in significant switching delays, long software response times, and a high risk of data loss. Furthermore, the false alarm rate increases dramatically as the battery ages, and if the voltage detection fails, the recorded data will be lost. Utility Model Content

[0007] The purpose of this invention is to address the shortcomings of existing technologies by proposing a real-time high-definition synchronous audio and video recording terminal.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a real-time high-definition synchronous audio and video recording terminal, comprising a main power supply, a shell, a camera module, an audio recording module, and a main control board. The main control board integrates a rubidium atomic clock chip, and the clock output terminal of the rubidium atomic clock chip is connected to the image sensor clock input terminal of the camera module and the ADC clock input terminal of the audio recording module through a coaxial shielded cable. An SRAM frame buffer is provided inside the main control board.

[0009] Preferably, the clock signal output frequency of the rubidium atomic clock chip is 10MHz, and the rubidium atomic clock chip synchronously drives the sampling clock of the image sensor and the ADC through a frequency divider circuit.

[0010] Preferably, both ends of the coaxial shielded cable are provided with impedance matching circuits, and the matching impedance of the impedance matching circuits is 50 ohms.

[0011] Preferably, the SRAM frame buffer adopts a FIFO physical stacking architecture.

[0012] Preferably, the recording module includes a microphone, which is isolated from the housing by a silicone hose. The microphone is covered by an acoustic waveguide with an aperture of 0.5 mm and a honeycomb shape.

[0013] Preferably, the side wall of the housing is provided with a multi-protocol interface module, which includes switchable HDMI, SDI and USB-C physical interfaces, and the interface contacts of the multi-protocol interface module all use flexible pins.

[0014] Preferably, the back of the main control board is provided with a hot-swappable SSD expansion slot, and the slot of the hot-swappable SSD expansion slot is provided with a physical write protection switch.

[0015] Preferably, a lithium battery compartment is provided at the bottom of the outer casing, and the main power supply is connected to the lithium battery in the lithium battery compartment through a physical relay switching circuit.

[0016] In summary, this utility model has the following beneficial effects:

[0017] 1. This utility model integrates a rubidium atomic clock chip on the main control board. The clock signal is directly connected to the clock end of the image sensor of the camera module and the clock end of the ADC of the recording module through a coaxial shielded cable, eliminating the software timing path. Furthermore, the SRAM frame buffer physically stacks and stores audio and video frames according to the atomic clock timestamps, achieving hardware-level timing alignment. This greatly reduces the audio-visual synchronization error, eliminates the problem of lip-sync asynchrony, and ensures that the clock signal transmission distortion rate is low by using a coaxial shielded cable and impedance matching circuit. It avoids timing drift caused by electromagnetic interference, and the physical stacked storage architecture avoids the risk of CPU scheduling delay, greatly reducing the frame loss rate.

[0018] 2. The microphone of this utility model is physically isolated from the outer shell by a silicone tube, which blocks the transmission of device vibration. The silicone tube attenuates most of the mechanical vibration noise, greatly reducing the distortion rate. Through the external nested 0.5mm diameter honeycomb acoustic waveguide, the honeycomb structure filters low-frequency noise in the environment, focuses the energy of key audio bands, and directionally enhances the 20kHz human voice frequency band.

[0019] 3. The lithium battery compartment of this utility model is connected to the main power supply through a physical relay switching circuit. The pure hardware switching mechanism without software intervention greatly reduces the response delay and the data loss rate during power switching. In addition, it automatically switches to battery power supply in the event of a sudden power outage. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the module of this utility model;

[0021] Figure 2 This is a schematic diagram showing the module positions of this utility model;

[0022] Figure 3 This is a flowchart of the present invention.

[0023] Figure label:

[0024] 1. Housing; 101. Multi-protocol interface module; 102. Flexible pins; 103. Lithium battery compartment; 104. Physical relay switching circuit;

[0025] 2. Camera module;

[0026] 3. Recording module; 301. Microphone; 302. Silicone tubing; 303. Acoustic waveguide;

[0027] 4. Main control board; 401. Rubidium atomic clock chip; 402. Coaxial shielded cable; 403. SRAM frame buffer; 404. Frequency divider circuit; 405. Impedance matching circuit; 406. Hot-swappable SSD expansion slot; 407. Physical write protection switch. Detailed Implementation

[0028] To make the technical means, creative features, and achieved objectives and effects of this utility model easier to understand, the present utility model is further described below with reference to specific embodiments and accompanying drawings. However, the following embodiments are merely preferred embodiments of this utility model and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments described in the implementation plan without creative effort are all within the protection scope of this utility model.

[0029] The specific embodiments of this utility model are described below with reference to the accompanying drawings:

[0030] Example 1:

[0031] refer to Figures 1-3 A real-time high-definition synchronous audio and video recording terminal includes a main power supply, a housing 1, a camera module 2, an audio recording module 3, and a main control board 4. The main control board 4 integrates a rubidium atomic clock chip 401. The clock output terminal of the rubidium atomic clock chip 401 is connected to the image sensor clock input terminal of the camera module 2 and the ADC clock input terminal of the audio recording module 3 through a coaxial shielded cable 402. An SRAM frame buffer 403 is provided inside the main control board 4.

[0032] Specifically, the main control board 4 integrates a rubidium atomic clock chip 401. The clock signal is directly connected to the clock end of the image sensor of the camera module 2 and the clock end of the ADC of the recording module 3 through a coaxial shielded cable 402. The SRAM frame buffer 403 physically stacks and stores audio and video frames according to the atomic clock timestamps. The rubidium atomic clock chip 401 provides a μs-level clock source, eliminating software time synchronization delay and greatly reducing audio-visual synchronization error, solving the problem of lip-sync issues in recording scenarios. The coaxial shielded cable 402 blocks electromagnetic interference, reduces clock signal distortion, and ensures a small deviation rate in multi-device collaboration. The physical stacked storage architecture avoids CPU scheduling risks, resulting in a small frame loss rate and meeting the data integrity requirements for interviews and judicial evidence collection.

[0033] The rubidium atomic clock chip 401 outputs a clock signal at a frequency of 10MHz. The rubidium atomic clock chip 401, via a frequency divider circuit 404, synchronously drives the sampling clocks of the image sensor and the ADC. Impedance matching circuits 405 are provided at both ends of the coaxial shielded cable 402, with a matching impedance of 50 ohms.

[0034] Specifically, the frequency divider circuit 404 divides the 10MHz signal from the rubidium atomic clock to drive the image sensor and ADC. The impedance matching circuit 405 is integrated into the coaxial cable terminal. The frequency divider circuit 404 ensures that the sampling clock frequency is physically matched with the sensor chip, reducing timing jitter and avoiding video ghosting. The impedance matching circuit 405 reduces the signal reflectivity, so that the signal-to-noise ratio is maintained even during long-distance transmission.

[0035] The SRAM frame buffer 403 uses a FIFO physical stacking architecture.

[0036] Specifically, the SRAM frame buffer 403 uses a continuous address space to sequentially store frame data. The hardware-level FIFO structure avoids the risk of memory fragmentation, ensures the integrity of continuous recording frames, and the sequential storage reduces addressing latency, greatly improving the data throughput rate.

[0037] The recording module 3 includes a microphone 301, which is isolated from the housing 1 by a silicone hose 302. The microphone 301 is covered by an acoustic waveguide 303 with an aperture of 0.5 mm and a honeycomb shape.

[0038] Specifically, the honeycomb duct filters ambient noise above 20kHz, the silicone tubing 302 attenuates equipment operation vibrations, and the audio distortion rate is reduced.

[0039] The side wall of the casing 1 is equipped with a multi-protocol interface module 101, which includes switchable HDMI, SDI, and USB-C physical interfaces. The interface contacts of the multi-protocol interface module 101 all use flexible pins 102. The back of the main control board 4 is equipped with a hot-swappable SSD expansion slot 406, and the slot of the hot-swappable SSD expansion slot 406 is equipped with a physical write-protection switch 407.

[0040] Specifically, the main control board 4 has a hot-swappable SSD expansion slot 406 on the back, which supports changing the storage medium during recording, extending the device's battery life. The physical write protection switch 407 reduces the risk of accidental deletion and meets the video recording anti-tampering standard. The hot-swappable design supports changing the SSD during recording, which increases the battery life of a single device.

[0041] A lithium battery compartment 103 is provided at the bottom of the outer casing 1. The main power supply is connected to the lithium battery in the lithium battery compartment 103 through a physical relay switching circuit 104.

[0042] Specifically, hardware switching reduces latency, avoids data loss due to power outages, withstands current surges, adapts to unstable voltage scenarios such as automotive applications, and improves the equipment's applicable environment.

[0043] Example 2:

[0044] refer to Figures 1-3 Staff members used the structure disclosed in this utility model in the news department of a provincial television station. Reporters carried this real-time high-definition synchronous audio and video recording terminal to a location for on-site reporting. The equipment configuration is as follows: the outer casing 1 is made of aviation aluminum CNC unibody molding; the main control board 4 is equipped with a Microsemi SA.45s rubidium atomic clock chip 401, which is directly connected to the clock end of the Sony IMX585 image sensor in the camera module 2 and the clock end of the TIPCM4222 ADC in the recording module 3 via an RG316 type coaxial shielded cable 402. The SRAM frame buffer 403 uses an ISSIIS61WV51216BLL chip to construct a FIFO physical stacking architecture.

[0045] At 9:30 AM, the reporter pressed the recording button outdoors, and the equipment loaded the preset parameters of 1080P resolution and 30 frames per second. The rubidium atomic clock chip 401 immediately output a 10MHz reference clock, which, after being divided by the frequency divider circuit 404, drives the image sensor and ADC to sample synchronously. The impedance matching circuit 405 stabilizes the impedance of the coaxial cable termination at 50 ohms, eliminating signal reflection. At this time, strong winds caused the equipment stand to sway, but the microphone 301 was flexibly connected to the outer shell 1 through the 8mm diameter silicone hose 302, effectively attenuating mechanical vibrations; the externally nested 6061 aluminum alloy honeycomb acoustic waveguide 303 with a 0.5mm aperture directionally filtered low-frequency noise from wind and rain, allowing the reporter's voice to maintain a signal-to-noise ratio of 85dB even in an ambient noise environment of 90dB.

[0046] During a power outage, the physical relay switching circuit 104 switched power to the CATL 10000mAh ternary lithium battery in the lithium battery compartment 103 within 8 milliseconds, ensuring smooth and uninterrupted video recording. At 11:00 AM, the device indicated that storage was nearly full. While recording continuously, the reporter removed the Kingston A20001 TBSSD from the hot-swappable SSD expansion slot 406. The physical write-protect switch 407 automatically locked the old drive's data to prevent tampering the moment the new drive was inserted. At 2:00 PM, after the interview concluded, the reporter activated the write-protect switch to generate AES256 encrypted data packets. An oscilloscope confirmed an audio-visual synchronization error of 3.2 milliseconds, far below the industry standard of 20 milliseconds. Throughout the process, the device was directly connected to the satellite broadcast van via the HDMI interface of the multi-protocol interface module 101. The flexible pins 102 maintained a contact resistance of less than 0.1 ohms after 27 insertions and removals. The device achieved 9 hours of uninterrupted high-definition recording in extreme conditions, and the raw data was certified by a testing center to meet broadcast-grade audio-visual synchronization standards.

[0047] The working principle of this utility model is as follows: When the staff starts the audio and video recording equipment and presses the record button, the system automatically loads the preset parameters, starts the rubidium atomic clock hardware clock source, and directly connects the clock end of the camera module 2 and the microphone module through the coaxial shielded cable 402 to achieve μs-level hardware timing synchronization of audio and video acquisition, eliminating software timing delay; the time code generated by the atomic clock is superimposed on the bottom of the recorded first frame; if the recording is interrupted due to insufficient storage space or equipment failure, the hot-swappable SSD expansion slot 406 medium is replaced in an emergency. During the replacement process, the physical relay switches to lithium battery power within 10ms to ensure zero frame loss during recording; the microphone 301 isolates the equipment vibration through the silicone hose 302 and the nested honeycomb acoustic waveguide 303 directionally filters the environmental noise below 20kHz to ensure that the signal-to-noise ratio of the human voice frequency band is ≥30dB; after the recording ends, the staff immediately activates the physical write protection switch 407 to cut off the SSD write channel, generates an AES-256 encrypted data copy, and after three parties verify the integrity of the image and the lip-sync, it is handed over for sealing.

[0048] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A real-time high-definition synchronous audio and video recording terminal, comprising a main power supply, a casing (1), a camera module (2), an audio recording module (3), and a main control board (4), characterized in that: The main control board (4) integrates a rubidium atomic clock chip (401). The clock output terminal of the rubidium atomic clock chip (401) is connected to the image sensor clock input terminal of the camera module (2) and the ADC clock input terminal of the recording module (3) through a coaxial shielded cable (402). The main control board (4) is equipped with an SRAM frame buffer (403).

2. The real-time high-definition synchronous audio and video recording terminal according to claim 1, characterized in that: The clock signal output frequency of the rubidium atomic clock chip (401) is 10MHz. The rubidium atomic clock chip (401) synchronously drives the sampling clock of the image sensor and the ADC through the frequency divider circuit (404).

3. The real-time high-definition synchronous audio and video recording terminal according to claim 1, characterized in that: Both ends of the coaxial shielded cable (402) are provided with impedance matching circuits (405), and the matching impedance of the impedance matching circuits (405) is 50 ohms.

4. A real-time high-definition synchronous audio and video recording terminal according to claim 1, characterized in that: The SRAM frame buffer (403) adopts a FIFO physical stacking architecture.

5. A real-time high-definition synchronous audio and video recording terminal according to claim 1, characterized in that: The recording module (3) includes a microphone (301), which is isolated from the outer shell (1) by a silicone tube (302). The microphone (301) is covered by an acoustic waveguide (303), which has an aperture of 0.5 mm and is honeycomb-shaped.

6. A real-time high-definition synchronous audio and video recording terminal according to claim 1, characterized in that: The outer casing (1) has a multi-protocol interface module (101) on its side wall. The multi-protocol interface module (101) includes switchable HDMI, SDI and USB-C physical interfaces. The interface contacts of the multi-protocol interface module (101) all use elastic pins (102).

7. A real-time high-definition synchronous audio and video recording terminal according to claim 1, characterized in that: The main control board (4) has a hot-swappable SSD expansion slot (406) on the back, and the slot of the hot-swappable SSD expansion slot (406) is equipped with a physical write protection switch (407).

8. A real-time high-definition synchronous audio and video recording terminal according to claim 1, characterized in that: The bottom of the outer casing (1) is provided with a lithium battery compartment (103), and the main power supply is connected to the lithium battery in the lithium battery compartment (103) through a physical relay switching circuit (104).

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