CN104506798A - Portable video capture device - Google Patents

Abstract

The invention discloses a portable video capture device, and aims at solving the problem that as traditional limited video transmission needs a transmission cable, important information, namely a video signal cannot be easily applied to battlefield command control. The portable video capture device comprises video capture equipment and a wireless local area network command system, wherein the video capture equipment comprises a video capture module and a video encoding module; the wireless local area network command system comprises a handheld table and a vehicular-locating set; the video collection module is used for collecting an analogue video signal of an original scene image, and transforming into a digital signal; the video encoding module is used for carrying out encoding compression on the digital signal output by the video capture module, and transforming into an H.264 video code stream, and transmitting the encoded H.264 video code stream to a wireless local area network handheld table through a network interface; the handheld table is used for wirelessly transferring the H/264 video code stream to the remote vehicular-locating set. The portable video capture device is relatively small in size and relatively light in weight, is powered by virtue of a built-in battery, and is free of limitation of a data transmission cable, so that the portable video capture device can be used as a man-portable video capture device.

Description

A kind of portable video harvester

Technical field

The present invention relates to Video coding transmission and wireless telecommunications research field, be specifically related to a kind of portable video harvester.

Background technology

Modern war changes from the mechanization operation of industrial age to the informationization operation of information age.The overall command system of army little by little tends to flattening, the mode that the order command of changing over is assigned layer by layer, but settle at one go order command is delivered to foremost.This just proposes new requirement to modern communication systems, enables the forefront that the fight instruction of officers and men is safe, clear, be delivered to position quickly.

Multimedia dispatching system is important means and the instrument that order command is passed on by army.Video information, as most important multimedia messages, in multimedia dispatching system, has very important effect.How video information fast and effeciently to be transmitted is the key determining that command of armed force operation and the anti-dangerous process of the disaster relief are effectively run fast.

Current Video transmission system mainly contains Analogvideotransmission mode and digital video transmission mode.Analog video gathers vision signal with analog video camera, and the analog video of output is transferred out by coaxial cable, is shown by the analog video display terminal of far-end.Digital video transmission mode, be the head end video direct coding compression that will collect, become digital signal, the mode directly transmitted by ethernet network is transmitted.No matter be Analogvideotransmission or the digital video transmission mode by Ethernet, all transmitted by corresponding cable, this can meet the demands under fixed scene.But video acquisition front end and aobvious control terminal are in for motor-driven carrier (such as vehicle, individual soldier hand-held)---video acquisition front end and aobvious control terminal all may change position at any time in such cases, substantially can not go frequently to lay the communications cable, thus wire transmission just becomes the obstacle of an application.

Because cost is low, WLAN (wireless local area network) develops rapidly in the decades after appearance, particularly along with introducing several cipher mode such as wired equivalent protocol (WEP), Temporal Key Integrirty Protocol (TKIP) sum counter pattern cypher block chaining message integrity code agreement (CCMP), fail safe improves, it enters Rapid development stage, obtains extensive use at civil area.The current whole world is total is using WLAN (wireless local area network) more than 500,000,000 people.

Summary of the invention

For the deficiencies in the prior art, the invention provides a kind of portable video harvester, solving traditional Limited Video transmission needs transmission cable, thus is difficult to the problem this important information of vision signal being used for battleficld command control.

In order to solve the problems of the technologies described above, the object of the invention is to be achieved through the following technical solutions,

The invention provides a kind of portable video harvester, this device is made up of following two parts:

(1) video capture device

Video capture device comprises video acquisition module and video encoding module.Video acquisition module comprises camera lens, cmos sensor and digitizer.Video encoding module comprises video encoding unit.Camera lens and cmos sensor, in conjunction with work, gather original image information, obtain PAL analog video.Digital signal is converted to afterwards by digitizer.Video encoding unit carries out compressed encoding to this digital signal.In order to obtain better compression effectiveness, video compression coding adopts the H.264 coded format of current extensive use.

The decoding digital video chip TVP5147 that digitizer is produced by TI company and peripheral circuit are formed.After the pal mode analog video input TVP5147 that video camera exports, change digital signal into, output format is ITU-R BT.656.

Leonardo da Vinci's dsp chip TMS320DM6437 that video encoding module is produced with TI company, for core, builds necessary peripheral circuit and forms.The ITU-R BT.656 formatted data that Video processing front end VPFE on TMS320DM6437 receives TVP5147 output carries out preliminary treatment, effective image data is put into the assigned address of DDR2.Run H.264 encryption algorithm in TMS320DM6437, each frame image data left in DDR2 is encoded.TMS320DM6437 accesses external flash Flash chip by external memory interface EMIF, and Flash chip is the memory carrier of application program and initial-configuration data; Ethernet MAC controller EMAC peripheral hardware integrated in TMS320DM6437 and PHY chip form a perfect Ethernet interface, the H.264 code stream that obtains of encoding is transferred to command post's WLAN (wireless local area network) hand-held station by this Ethernet interface, hand-held station and then carry out wireless forwarding to the back-end.

(2) command post's wireless local area network (WLAN) system

Command post's WLAN (wireless local area network) is made up of Vehicle mounted station and hand-held station, possesses good mobility, and belonging to group army, command posts at different levels fast reserve provides communication support; Can the broadband high-speed transmission platform of fast construction command post overlay area, for each key element of command post and commander at different levels provide reliably, stablize, the safe Integrated Services Transmission such as data, speech, video; By access Tactical Internet, interconnecting of command posts at different levels data and voice service can be ensured, realize information sharing, improve command ability.

Vehicle mounted station, as the signal centre of WLAN (wireless local area network), is generally positioned at command centre, supports starlike networking and chain networking.Hand-held station, as communication end node, can be distributed in the anywhere in Vehicle mounted station signal cover.

In the present invention, Vehicle mounted station is positioned at command car, and hand-held station, with video capture device, is carried into investigation, operation field by individual soldier.

Vision signal, by utilizing the WLAN (wireless local area network) transfer function of high-speed radio data radio station, is gone out by wireless transmission by the present invention.Because equipment volume is less, lighter in weight, uses internal battery power and there is not the restriction of data transmission cable, therefore can be used as the portable video harvester that a kind of individual soldier carries.This device can Real-time Collection investigation, operation front scene video information, and to be wirelessly transmitted in neighbouring command centre, to be convenient to commanding and to make along with the progress of task or the change of environment and commanding flexibly.When broad view, wireless transmission distance is maximum reaches 3 kilometers.

Accompanying drawing explanation

Fig. 1 is video capture device composition frame chart of the present invention;

Fig. 2 is video capture device embedded software flow chart of the present invention.

Embodiment

Below in conjunction with drawings and Examples, the present invention will be further described.

Embodiment 1

(1) video capture device real-time proposals

A kind of portable video harvester, first, in conjunction with actual needs, selects a suitable camera lens and cmos sensor.According to the needs that operation, investigation scene video gather, in order to ensure certain angle of visual field, select 8mm to focus the camera lens of focal length, cmos sensor selects 1/2.7 〞, and now the angle of visual field is 34.5 ° × 25.7 °, can meet general application demand.

Secondly, according to the explanation in technical scheme, the hardware circuit of acquisition module and coding module in design video capture device.

The circuit part design of acquisition module and coding module is on one piece of circuit board.As shown in Figure 1, the decoding digital video chip TVP5147 that produced by TI company of analog video digitizer and peripheral circuit are formed.After the pal mode analog video input TVP5147 that video camera exports, change digital signal into, output format is ITU-R BT.656.

TMS320DM6437 is a good digital media processor chips that TIX issues.This equipment mainly applies the following resource on chip: 1) Video processing front end (Video Processing Front End, VPFE) the BT.656 Digital video protocols signal for exporting TVP5147 carries out preliminary treatment, every frame image data is put in double data rate Synchronous Dynamic Random Access Memory (Double-Data-Rate Two Synchronous Dynamic Random Access Memory, DDR2 SDRAM) and carry out buffer memory; 2) central processing unit (Central Processing Unit, CPU) of chip is subsequently by built-in DDR2 controller, reads the compression of each frame coding video data; 3) chip accesses external flash (Flash Memory) chip by external memory interface (External Memory Interface, EMIF).The latter is the memory carrier of application program and initial-configuration data; 4) Ethernet MAC controller (Ethernet Media Access Controller, and physical layer (Ethernet Physical Layer EMAC), PHY) chip forms a perfect Ethernet interface, for externally being transferred out by Ethernet by the video flowing after compression coding.

Again, according to the explanation in technical scheme, TI Code Composer Studio development platform is write the embedded software of Video coding, transmission.

As shown in Figure 2, the workflow of software is: after device power work, first software start to carry out initialization to DSP kernel and On-Chip peripheral, then to the machine Mac address of reading pre-stored from I2C interface Flash, starts afterwards to configure digital video words chip TVP5147.Then initialization network, and wait for that client connects.Once after client connects, to H.264 encoding service initialization, distribute necessary resource.Open VPFE again to interrupt.In VPFE break in service function, preliminary treatment is carried out to one-frame video data after TVP5147 digitlization: the interleaved signal making PAL, buffer memory is data of lining by line scan, can only the restriction of encoded progressive scan video signal to meet H.264 encoder that TI provides.After completing with process, by the semaphore code in DSP/BIOS embedded OS, trigger thread of H.264 encoding, start to encode to these frame data.After having encoded, then believed by another semaphore, trigger network service thread, externally send the data after this frame coding.

Meanwhile, according to the physical dimension of each parts in video capture device inside, design, process equipment shell mechanism.

Finally, Denso and the machine dress of video capture device is completed.

(2) command post's wireless local area network (WLAN) system

The equipment that command post's wireless local area network (WLAN) system can select miscellaneous equipment manufacturer to produce, system comprises Vehicle mounted station and each one of hand-held station.In order to make the effective operation scope of portable video harvester larger, mobility is better, should ensure that the communication distance between Vehicle mounted station and hand-held station should be not less than 1 kilometer.In order to make the video of transmission have certain quality, reducing frame loss rate, should ensure that between hand-held station and Vehicle mounted station, transmitted data rates is not less than 250kbps.

Claims (5)

1. a portable video harvester, is characterized in that, comprises video capture device and command post's wireless local area network (WLAN) system; Described video capture device comprises video acquisition module and video encoding module; Described command post wireless local area network (WLAN) system comprises hand-held station and Vehicle mounted station; Described video acquisition module, gathers the analog video signal of original scene image, and is converted to digital signal; Described video encoding module, the encoding digital signals compression that video acquisition module is exported, be converted to H.264 video code flow, the H.264 code stream obtained of encoding is transferred to command post's WLAN (wireless local area network) hand-held station by network interface, and hand-held station and then distally Vehicle mounted station carry out wireless forwarding.

2. portable video harvester according to claim 1, is characterized in that, described video capture device comprises camera lens, cmos sensor, digitizer and video encoding unit; Camera lens and cmos sensor, in conjunction with work, gather original image information, obtain PAL analog video.

3. portable video harvester according to claim 2, it is characterized in that, described digitizer comprises decoding digital video chip TVP5147 and peripheral circuit, after described PAL analog video input TVP5147, change digital signal into, output format is ITU-R BT.656.

4. portable video harvester according to claim 2, is characterized in that, described video encoding module comprises TMS320DM6437 and peripheral circuit; The ITU-R BT.656 formatted data that Video processing front end VPFE on TMS320DM6437 receives TVP5147 output carries out preliminary treatment, effective image data is put into the assigned address of DDR2; Run H.264 encryption algorithm in TMS320DM6437, each frame image data left in DDR2 is encoded; TMS320DM6437 accesses external flash Flash chip by external memory interface EMIF, and Flash chip is the memory carrier of application program and initial-configuration data; Ethernet MAC controller EMAC peripheral hardware integrated in TMS320DM6437 and PHY chip form a perfect Ethernet interface, and the H.264 code stream obtained of encoding is transferred to command post's WLAN (wireless local area network) hand-held station by this Ethernet interface.

5. portable video harvester according to claim 1, is characterized in that, described Vehicle mounted station, as the signal centre of WLAN (wireless local area network), is positioned at command centre, supports starlike networking and chain networking; Hand-held station, as communication end node, is distributed in the anywhere in Vehicle mounted station signal cover.