阅读说明：本技术 一种用于测试数字摄像机视音频失步时间的系统 (System for testing video and audio out-of-step time of digital camera ) 是由 宋明 李鹍 王俊飞 张天宇 姚珍富 张强 李苏雯 乔静怡 侯克冰 张俊凯 张利飞 于 2019-09-18 设计创作，主要内容包括：本发明提出了一种用于测试数字摄像机视音频失步时间的系统,由显示终端、数字条码显示模块、高速拍摄模块、智能分析模块和音频信号发生模块、音频采集分析模块等部分组成。数字条码显示模块、高速拍摄模块和智能分析模块组成视频时延测试单元,音频信号发生模块和音频采集分析模块组成音频时延测试单元,智能分析模块计算视频时延和音频时延之间的差值,即被测摄像机的视音频失步时间；视频时延测试单元和音频时延测试单元,通过视频时延测试单元形成独立视频通路,进行视频时延测试；音频时延测试单元形成独立的音频通路,进行音频时延测试。本发明系统能实时、快速地计算数字摄像机视音频失步时间,有很好的重复性。(The invention provides a system for testing video and audio step-out time of a digital camera, which comprises a display terminal, a digital bar code display module, a high-speed shooting module, an intelligent analysis module, an audio signal generation module, an audio acquisition and analysis module and the like. The digital bar code display module, the high-speed shooting module and the intelligent analysis module form a video time delay test unit, the audio signal generation module and the audio acquisition and analysis module form an audio time delay test unit, and the intelligent analysis module calculates the difference value between the video time delay and the audio time delay, namely the video and audio step-out time of the tested camera; the video time delay testing unit and the audio time delay testing unit form an independent video channel through the video time delay testing unit to carry out video time delay testing; the audio time delay test unit forms an independent audio channel to carry out audio time delay test. The system of the invention can calculate the video and audio out-of-step time of the digital camera in real time and rapidly, and has good repeatability.)

1. A system for testing video and audio out-of-sync times of a digital camera, comprising:

the display terminal is connected with a tested camera;

the video time delay testing unit comprises a digital bar code display module, a high-speed shooting module and an intelligent analysis module, wherein the digital bar code display module is used for providing a first time mark, the camera to be tested shoots the first time mark on the digital bar code display module and outputs the first time mark to the display terminal to be used as a second time mark for displaying; the high-speed shooting module shoots the first time mark and the second time mark at the same time and outputs a time mark image to the intelligent analysis module; the intelligent analysis module is used for outputting the time difference between the first time mark and the second time mark as video time delay;

the audio time delay testing unit comprises an audio signal generating module and an audio collecting and analyzing module, wherein the audio signal generating module is respectively connected with the audio collecting and analyzing module, the tested camera and the intelligent analyzing module, and the audio signal generating module is used for outputting a first audio signal and respectively outputting the first audio signal to the audio collecting and analyzing module and the tested camera; the audio acquisition and analysis module receives the first audio signal and a second audio signal output by the tested camera and outputs audio time delay, and the audio acquisition and analysis module is also used for outputting the audio time delay to the intelligent analysis module;

and the intelligent analysis module is also used for outputting the difference value between the video time delay and the audio time delay as the video and audio out-of-step time of the tested camera.

2. The system for testing the video and audio step-out time of a digital camera as claimed in claim 1, wherein the digital bar code display module comprises a stepping motor, two rotating wheels, a belt and a bar code, the two rotating wheels are spaced by a preset distance; the belt is sleeved on the two rotating wheels so that the two rotating wheels rotate synchronously; the bar codes are arranged on the belt uniformly; the stepping motor is connected with one rotating wheel and used for driving the rotating wheel to rotate.

3. The system for testing the audio-visual step-out time of a digital camera as claimed in claim 2, wherein the bar codes are provided with codes, and the codes on a plurality of the bar codes are arranged in an equal difference mode.

4. The system for testing the audio-visual step-out time of a digital camera as claimed in claim 3, wherein the bar code is provided with a code range of 0-999.

5. The system for testing audio and video out-of-step time of a digital video camera of claim 2, wherein the stepper motor is a speed adjustable motor.

6. The system for testing audio and video out-of-sync time of a digital video camera of claim 1, wherein the audio capture analysis module outputs the audio delay based on a time difference between the first audio signal and the second audio signal.

7. The system for testing the video and audio out-of-step time of a digital camera according to any one of claims 1 to 6, wherein the intelligent analysis module comprises an image capture unit, a bar code recognizer, a main controller and a processor, the image capture unit is used for capturing the time mark image captured by the high-speed capture module and outputting the captured time mark image to the bar code recognizer, and the bar code recognizer is used for recognizing the first time mark and the second time mark in the time mark image; the main controller is used for controlling the audio signal generator and controlling the time interval when the image capturing unit captures the time mark image; the processor is configured to output a time difference between the audio delay and the video delay.

8. The system for testing audio-visual step-out time of a digital video camera of claim 7, wherein the audio signal generator comprises a controller and a sinusoidal signal generator.

9. The system for testing the video and audio out-of-step time of a digital video camera as claimed in claim 6, wherein the controller is connected to the intelligent analysis module, receives the control command from the intelligent analysis module, and controls the frequency and amplitude of the sinusoidal signal generator according to the control command.

10. The system for testing video and audio step-out time of a digital video camera of claim 8, wherein the main controller is connected to the controller, and the main controller is configured to control the controller to provide the audio signal generator with a random sound signal template and adjust the transmission time interval of the first audio signal.

Technical Field

The invention relates to the technical field of video monitoring, in particular to a system for testing video and audio out-of-step time of a digital camera.

Background

At present, in the field of video monitoring systems, the quality of video images and the fluency of videos are the most important technical indexes, but digital video monitoring cameras have an audio coding function at the same time, and audio and video have the same importance in certain specific occasions, and audio is also used as important monitoring data, and sound and images need to be recorded at the same time. This is necessary to ensure the synchronization of sound and image. Because the audio and the video adopt different coding technologies and packaging formats, the final presentation of the video and the audio is asynchronous, and therefore, the video and the audio synchronism of the digital camera is judged by accurately testing the out-of-step time of the video and the audio. It is obvious to see if the audio signal leads the video signal by 90ms or if the audio signal lags the video signal by 185 ms.

The video and audio desynchronization of the existing test digital video monitoring camera mainly comprises the steps of marking an audio label on a video stream and calculating the time delay of audio through a video frame rate, and the test method has two problems: 1) the time delay of the audio depends on the frame rate of the video, and the time delay of the audio is integral multiple of the time interval of each frame of the video; 2) the audio and video sequence with audio label in the video stream has the risk of desynchronization when transmitting to the digital video monitoring camera to be tested.

Disclosure of Invention

In view of this, the present invention provides a system for testing video and audio out-of-step time of a digital video camera, which aims to solve the problem of how to test the video and audio out-of-step time of the digital video surveillance camera with high precision.

In one aspect, the present invention provides a system for testing video and audio out-of-sync time of a digital camera, comprising:

the display terminal is connected with a tested camera;

the video time delay testing unit comprises a digital bar code display module, a high-speed shooting module and an intelligent analysis module, wherein the digital bar code display module is used for providing a first time mark, the camera to be tested shoots the first time mark on the digital bar code display module and outputs the first time mark to the display terminal to be used as a second time mark for displaying; the high-speed shooting module shoots the first time mark and the second time mark at the same time and outputs a time mark image to the intelligent analysis module; the intelligent analysis module is used for outputting the time difference between the first time mark and the second time mark as video time delay;

the audio time delay testing unit comprises an audio signal generating module and an audio collecting and analyzing module, wherein the audio signal generating module is respectively connected with the audio collecting and analyzing module, the tested camera and the intelligent analyzing module, and the audio signal generating module is used for outputting a first audio signal and respectively outputting the first audio signal to the audio collecting and analyzing module and the tested camera; the audio acquisition and analysis module receives the first audio signal and a second audio signal output by the tested camera and outputs audio time delay, and the audio acquisition and analysis module is also used for outputting the audio time delay to the intelligent analysis module;

and the intelligent analysis module is also used for outputting the difference value between the video time delay and the audio time delay as the video and audio out-of-step time of the tested camera.

Furthermore, the digital bar code display module comprises a stepping motor, two rotating wheels, a belt and a bar code, wherein the two rotating wheels are arranged at a preset interval; the belt is sleeved on the two rotating wheels so that the two rotating wheels rotate synchronously; the bar codes are arranged on the belt uniformly; the stepping motor is connected with one rotating wheel and used for driving the rotating wheel to rotate.

Furthermore, the bar codes are provided with codes, and the codes on the bar codes are arranged in an equal difference mode.

Furthermore, the code range of the bar code is 0-999.

Further, the stepping motor is a rotating speed adjustable motor.

Further, the audio acquisition and analysis module outputs the audio time delay according to the time difference between the first audio signal and the second audio signal.

Further, the intelligent analysis module comprises an image capture unit, a barcode recognizer, a main controller and a processor, wherein the image capture unit is used for capturing the time stamp image captured by the high-speed shooting module and outputting the captured time stamp image to the barcode recognizer, and the barcode recognizer is used for recognizing the first time stamp and the second time stamp in the time stamp image; the main controller is used for controlling the audio signal generator and controlling the time interval when the image capturing unit captures the time mark image; the processor is configured to output a time difference between the audio delay and the video delay.

Further, the audio signal generator includes a controller and a sinusoidal signal generator.

Further, the controller is connected with the intelligent analysis module, receives a control instruction of the intelligent analysis module, and controls the frequency and the amplitude of the sinusoidal signal generator according to the control instruction.

Further, the main controller is connected with the controller, and the main controller is configured to control the controller to provide a random sound signal template for the audio signal generator, and adjust a sending time interval of the first audio signal.

Compared with the prior art, the video time delay testing unit and the audio time delay testing unit are arranged, the video time delay testing unit and the audio time delay testing unit are respectively used for forming the independent video channel so as to perform video time delay testing, the audio time delay testing unit is used for forming the independent audio channel so as to perform audio time delay testing, and the time difference between the video time delay testing result and the audio time delay testing result is calculated so as to obtain the final video and audio step-out time.

Furthermore, the system for testing the video and audio step-out time of the digital camera of the invention enables the video and audio step-out test to be simple and accurate, and simultaneously can independently test the time delay of video and audio. The system can control the video and audio out-of-step error to be in millisecond level at most according to the error requirement.

Furthermore, by arranging the digital bar code display module, the accuracy of the video delay and audio delay results is greatly improved by taking the digital bar code display module as a reference for calculating time.

Furthermore, the audio time delay test method adopts a controllable random signal as the output of the audio signal generator, an analog audio signal as the input of the test and double analog signal tests, so that the audio time delay measurement is more accurate, and the error can be controlled within 1% millisecond.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 is a functional block diagram of a system for testing video and audio out-of-sync time of a digital video camera according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a digital barcode display module according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an audio signal generator according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of an audio signal provided by an embodiment of the present invention;

fig. 5 is a schematic structural diagram of an intelligent analysis module according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

Referring to fig. 1, an embodiment of the present invention provides a system for testing video and audio out-of-step time of a digital camera, including: the device comprises a display terminal 1, a video time delay testing unit and an audio time delay testing unit, wherein the display terminal 1 is connected with a tested camera 2, data transmission is carried out between the display terminal 1 and the tested camera 2, namely, the tested camera 2 outputs image data shot by the tested camera to the mobile terminal for displaying.

Specifically, the video time delay testing unit comprises a digital barcode 31 display module 3, a high-speed shooting module 7 and an intelligent analysis module 6, wherein the digital barcode 31 display module 3 is used for providing a first time mark, and the camera 2 to be tested shoots the first time mark on the digital barcode 31 display module 3 and outputs the first time mark to the display terminal 1 to be displayed as a second time mark; the high-speed shooting module 7 shoots the first time mark and the second time mark simultaneously and outputs a time mark image to the intelligent analysis module 6; the intelligent analysis module 6 is configured to output a time difference between the first time stamp and the second time stamp as a video time delay.

Specifically, the audio time delay testing unit comprises an audio signal generating module 4 and an audio collecting and analyzing module 5, wherein the audio signal generating module 4 is respectively connected with the audio collecting and analyzing module 5, the tested camera 2 and the intelligent analyzing module 6, and the audio signal generating module 4 is used for outputting a first audio signal and respectively outputting the first audio signal to the audio collecting and analyzing module 5 and the tested camera 2; the audio acquisition and analysis module 5 receives the first audio signal and the second audio signal output by the tested camera 2, and outputs an audio time delay, and the audio acquisition and analysis module 5 is further configured to output the audio time delay to the intelligent analysis module 6.

Specifically, the intelligent analysis module 6 is further configured to output a difference between the video delay and the audio delay as the video and audio out-of-step time of the tested camera 2.

In particular, the audio signal generation module 4 is preferably an audio signal generator

It can be seen that, by arranging the video time delay test unit and the audio time delay test unit, independent video channels are formed through the video time delay test unit respectively to perform video time delay test, independent audio channels are formed through the audio time delay test unit to perform audio time delay test, and the time difference between the test results of the video time delay and the audio time delay is calculated to obtain the final video and audio step-out time.

Specifically, the display terminal 1 and the camera 2 to be tested are connected and communicated in a wired or wireless manner, and those skilled in the art should know the wired or wireless connection manner between the two, which is not described herein again.

Specifically, the display terminal 1 may be a display, a PC, a notebook, or the like.

Referring to fig. 2, the digital barcode 31 display module 3 includes a stepping motor 34, two rotating wheels 33, a belt 32, and a barcode 31, where the two rotating wheels 33 are spaced by a preset distance; the belt 32 is sleeved on the two rotating wheels 33, so that the two rotating wheels 33 rotate synchronously; the bar codes 31 are arranged on the belt 32 in a uniform arrangement manner; the stepping motor 34 is connected with one of the rotating wheels 33 and is used for driving the rotating wheel 33 to rotate.

Specifically, the bar code 31 is provided with codes, and the codes on the bar codes 31 are arranged in an equal difference. The bar code 31 is provided with a code range of 0-999.

Specifically, the stepping motor 34 is a rotational speed adjustable motor.

It can be seen that the accuracy of the video delay and audio delay results is greatly improved by arranging the digital barcode 31 display module 3 and taking the digital barcode 31 display module 3 as a reference for calculating time.

In specific implementation, the digital barcode 31 display module 3 includes a stepping motor 34, a rotating wheel 33, a belt 32, and a barcode 31, where the barcode 31 is numbered according to 0 to 999 and is uniformly adhered to the belt 32, the stepping motor 34 drives the rotating wheel 33 to rotate, and the belt 32 is pulled to move so that the barcode 31 moves at a constant speed. The digital bar code 31 display module 3 provides the original time mark, namely the first time mark, for the tested camera 2.

Specifically, the imaging of the camera 2 to be tested is adjusted, so that the barcode 31 clearly displays the photographed image of the barcode 31 on the display terminal 1, that is, the second time stamp.

Specifically, the audio signal generating module 4 generates an audio signal, that is, a first audio signal, the frequency is between 300kHz and 3.4kHz, one path of the audio signal generated by the audio signal generating module 4 is input to the tested camera 2, the other path of the audio signal is input to the audio collecting and analyzing module 5, the audio signal output by the tested camera 2 is sent to the audio collecting and analyzing module 5, that is, the audio signal output by the tested camera 2 is a second audio signal, and the time difference between the two audio input signals, that is, the audio time delay, is calculated by the first audio signal and the second audio signal in the audio collecting and analyzing module 5.

Specifically, the high-speed shooting module 7 shoots the barcode 31 on the digital barcode 31 display module 3 and the barcode 31 displayed on the display terminal 1 at the same time, transmits the shot images to the intelligent analysis module 6, calculates the time difference between the barcode 31 on the display terminal 1 and the barcode 31 on the digital barcode 31 display module 3, namely the video time delay, and finally calculates the difference between the video time delay and the audio time delay, namely the video and audio step-out time.

As shown in connection with fig. 3, in particular, the audio signal generation module 4 includes a controller 41 and a sinusoidal signal generator 42. The controller 41 is connected to the intelligent analysis module 6, and the controller 41 receives a control instruction of the intelligent analysis module 6 and controls the frequency and amplitude of the sinusoidal signal generator 42 according to the control instruction. Specifically, the controller 41 is controlled by the intelligent analysis module 6, and the controller 41 can adjust the frequency and amplitude of the sinusoidal signal and the transmission of the signal.

In detail, as shown in fig. 4, the audio acquisition and analysis module 5 outputs the audio delay according to the time difference between the first audio signal and the second audio signal. Specifically, the audio acquisition and analysis module 5 receives the original signal and the processed signal at the same time, and calculates a time difference between the two signals, which is a time delay of the audio. The audio acquisition and analysis module 5 receives the original signal and the processed signal, i.e. the first audio signal and the second audio signal, and calculates a difference Δ t between the two signals, where Δ t is the audio delay.

It can be seen that the audio time delay test method adopts controllable random signals as the output of the audio signal generation module 4, analog audio signals as the input of the test, and double analog signal tests, so that the audio time delay measurement is more accurate, and the error can be controlled within 1% millisecond.

Particularly, after the whole system is operated, the video and audio distortion of the camera can be detected in real time, and the system operation efficiency and the accuracy of a test result are greatly improved.

Specifically, as shown in fig. 5, the intelligent analysis module 6 includes an image capture unit 62, a barcode recognizer 64, a main controller 61 and a processor 63, the image capture unit 62 is configured to capture the time stamp image captured by the high-speed capture module 7 and output the captured time stamp image to the barcode recognizer 64, and the barcode recognizer 64 is configured to recognize the first time stamp and the second time stamp in the time stamp image; the main controller 61 is configured to control the audio signal generating module 4, and control a time interval when the image capturing unit 62 captures the time stamp image; the processor 63 is configured to output the time difference between the audio delay and the video delay.

Specifically, the main controller 61 is connected to the controller 41, and the main controller 61 is configured to control the controller 41 to provide a random sound signal template for the audio signal generating module 4 and adjust the sending time interval of the first audio signal.

It can be seen that the audio time delay test method adopts controllable random signals as the output of the audio signal generation module 4, analog audio signals as the input of the test, and double analog signal tests, so that the audio time delay measurement is more accurate, and the error can be controlled within 1% millisecond.

Specifically, the image capture unit 62 captures an image captured by the high-speed capture module 7. The barcode recognizer 64 recognizes the two barcodes 31 photographed by the high-speed photographing module 7, and calculates a time difference between the two barcodes 31 according to the moving speed of the barcodes 31, that is, a time delay of the video. The main controller 61 provides a random sound signal template for the audio signal generation module 4 by controlling the controller 41 in the audio signal generation module 4, and adjusts the time interval of sending the audio signal; while also controlling the image grabbing unit 62 to grab the time interval. The processor 63 collects the difference between the audio delay calculated by the audio acquisition and analysis module 5 and the video delay, i.e. the video and audio out-of-step time.

Specifically, after the system normally operates, the high-speed shooting module shoots the bar codes on the display terminal and the digital bar code display module at the same time, the bar code on the terminal is 500, the bar code on the digital bar code display module is 800, and the difference value between the bar codes is 200. The intelligent analysis module calculates the difference value of two barcodes on the digital barcode display module which is shot twice continuously by the high-speed shooting module, the difference value of the two barcodes on the digital barcode display module which is shot continuously is 2, the frame rate of the high-speed shooting module is assumed to be 2000 frames, the time interval of the two barcodes is (1/2000) × 2 ═ 0.001s, the barcode time interval is known, and the time delay of a video is 200 × 0.001 ═ 0.200 s. The audio signal generating module sets the frequency of the audio signal to be 3kHz, the amplitude to be 500mv, the sending interval to be 1s, and the audio signal generator starts to send signals. The audio acquisition and analysis module receives a signal sent by the audio signal generator, records the starting time of 0.000s, receives an audio signal output by the tested camera, and also records the time of 0.100s, and the time is 0.100s which is the audio time delay after the time of 0.100-0.000 s is subtracted from the time of the starting time. Video and audio step-out time delay-video time delay-audio time delay-0.200-0.100 s.

Therefore, the invention makes the video and audio step-out test simple and accurate, and simultaneously can test the time delay of the video and the audio independently. The system can control the video and audio out-of-step error to be in millisecond level at most according to the error requirement.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.