CN1917622A - Sound and image transmission system and method of broadband videoconference in broadcast level - Google Patents

Abstract

The system thereof comprises: a broadcast wideband video session unit, a video and audio transmission unit and a network management unit. The method thereof comprises: 1) the audio and video signals are compressed into the MPEG-2 data stream; 2) making video and audio collection, switch and remote switch in broadcast level; 3) implementing the broadcast level wideband video session; 4) making inverse multiplexing for the communication line; 5) with TCP/IP, the network management messages are transmitted through packet switch network or PSTN network; 6) using Visual C++ programming language to edit the application software used in video session, video and audio transmission and network management.

Description

A kind of acoustic image transmission system and method for broadband videoconference in broadcast level

Technical field

The present invention relates to the acoustic image transmission system and the method for acoustic image processing and transmission technique field, particularly a kind of broadband videoconference in broadcast level.

Background technology

Video conference is called video conferencing or video conference again, and it is one and melts network, TV, compunication and data sharing technology etc. and be the system of one.System builds up the back requirement can be at meeting room by simple operations, can hold the whole network video conference in trans-city across a network limit, and image or computer information are watched in the limit, and the limit is carried out very important decision and disposed, and the parties concerned are listened to the reflection of making a strategic decision etc. in the limit.

Sixties beginning, world developed country begin one's study analog video meeting and commercialization gradually.At the end of the sixties, under compression coding technology promotes, turn to digital system by analogue system.At the initial stage eighties, develop 2Mb/s colorful digital video conferencing system.The mid-80, the develop rapidly of large scale integrated circuit technology, image encoding and decoding technique makes a breakthrough.The channel expense reduces, for the practical good development condition that provides is provided in video conference.The end of the eighties, International Telecommunications Union's (being present ITU-T) stipulated the mode switch standard of unified video input and output, algorithm, error checking and a plurality of intercommunications, has greatly promoted the development of video conference so far.

Since the mid-90, the develop rapidly of Internet has produced huge and deep effect to telecommunications industry, becomes one of focus that researcher and telecommunications, network and computer vendors pay close attention to gradually based on the video conferencing system of packet network.

Video conferencing system has truly, efficiently reaches characteristics of real time, be a kind ofly simple and effectively be used to manage, the technological means of commander and Coordination Decision.

The acoustic image transmission has also obtained development rapidly in recent years as the basis of video conferencing system.The acoustic image transmission relates to a plurality of technical fields such as video flow processing (comprising collection, compression, transmission, decompression, broadcast and management etc.) and compunication.

In the holding video conference process, need show the picture of required sub-venue in the main meeting-place, show the picture of main meeting-place or other sub-venues at sub-venue.If directly the video-voice frequency flow by IP network remote transmission broadcast level quality is inconceivable, this is because required bandwidth is excessive.For example, the image of TSC-system is with 640 * 480 resolution, and 24/pixel, the Mass Calculation of per second 30 frames, then required bandwidth are 28MB/s.And if with the speed rates of 28MB/s, the not compressed image in 15 seconds will take the disk space of 420MB, per minute then needs 1680MB (1.68GB), per hour needs 100.8GB.

Want remote transmission broadcast level quality video-voice frequency flow, must before transmission, compress it.The basic demand of compression is:

(1) after receiving terminal received compressed file and decompression, the picture quality of broadcast still can reach broadcast level, i.e. the file loss that compression causes does not influence the quality of broadcast.

(2) bandwidth of compression back file can be reduced to the admissible scope of general ip network.

Because it all is base unit with the frame that tv edit, stunt are made, so to being that the M-JPEG form that the unit compresses (compression in the frame) is successfully used to Digital Video System with the frame, particularly digital non-linear editing saving system.China's nonlinear editing system mostly adopts the M-JPEG compression of 4:1 at present, is considered to acceptable broadcast level level.When the 4:2:2 of Phase Alternation Line system digital signal adopted the 4:1 compression, its data transfer rate was 5MB/s (40Mb/s), and video frequency program hourly need take the 18GB disk space.In fact, unless use the circuit of enough bandwidth; Otherwise this compressed format also is that the user is unacceptable.

Can guarantee best video image quality, can improve compression ratio significantly again, to reduce data volume better, MPEG-2 is the optimality criterion that is used for the broadcast level video compression.

Moving Picture Experts Group-2 is used for the image of wideband transmit, and picture quality reaches the television broadcasting level, even the standard of HDTV.Compression is according to the principle that certain similitude is arranged between the moving image consecutive frame, by the similar situation of motion prediction with reference to former frame image and this two field picture.Remove the redundant data similar then, and only write down this frame data different with previous frame to former frame.Thereby improved compression of video data efficient greatly, this compression method is also referred to as the relevant compression of frame.The MPEG-2 compression is a unit with image sets (GOP), is made of I frame, B frame and P frame.Generally speaking, an image sets is made up of 15 frames.The 1st frame is an I frame, is followed successively by 1 P frame, and 2 B frames constitute IPBBPBB PBB thus ... structure.The I frame is called reference frame, is all start frames of reference of other frames.So the I frame is the frame that can put down in writing these frame all images data fully, also is called full frame.The P frame is a forward predicted frame, be according to the former frame image relatively remove the frame that constitutes to the similar data of preceding frame.The B frame is a bi-directional predicted frames, is the frame that obtains according to the comparison with front and back one two field picture.P frame and B frame are incomplete frames, and needs rely on the I frame and set up.

Because adopt motion prediction frame compress mode, so at video compression, Moving Picture Experts Group-2 has good effect.Under the prerequisite that obtains the broadcast level digital video-frequency quality, can realize the compression efficiency of 20:1, data transfer rate can be reduced to 1MB/s (8M b/s), and one hour video frequency program need take the 3.6GB space.Data space utilance height, network transmission efficiency are more than 5 times of M-JPEG system.

The compress mode that realizes Moving Picture Experts Group-2 has several different methods, relies on the hardware difficulty very big merely, and then speed is slow excessively to rely on software separately, and the best approach is hard soft combination.

Summary of the invention

The object of the present invention is to provide a kind of acoustic image transmission system and method for broadband videoconference in broadcast level.

A kind of acoustic image transmission system of broadband videoconference in broadcast level, comprise broadband videoconference in broadcast level device, acoustic image transmitting device and three devices of network administration apparatus, all devices and application software, broadband videoconference in broadcast level device, acoustic image transmitting device and network administration apparatus are by communication network and realize that the system integration technology of systemic-function is interconnected.

The capital equipment that the broadband videoconference in broadcast level device comprises is codec, ATM switch, inverse multiplexer, video/audio matrix, digital special effect cut bank, film titler, and the server and the terminal of operation application software.

Encoder is high-quality MPEG-2 video-voice frequency flow with the video/audio signal Real Time Compression, video output/output can be selected serial digital interface or PAL/NTSC composite signal, support the main profile at main level of MPEG-2 and the 4:2:2MP@ML (form of 1.5Mb～50Mb), Audio Processing is non-compression of SMPTE 302M and MPEG-1 Layer II form, is provided for the output interface and the atm network interface that is used to be connected ATM of the DVB/ASI of satellite transmission.Decoder decompression MPEG-2 video-voice frequency flow, transmit high-quality and real-time MPEG-2 digital video signal to provide, coded format and video bitrate comprise MPEG-1 (reaching 1.5Mb/s), MPEG-2MP@ML (reaching 15Mb/s) and MPEG-2 4:2:2P@ML (reaching 50Mb/s).

ATM switch, 2.5Gb/s the unblock exchange capacity of～10Gb/s, the LAN of complete series and wan interface, port type from T1/E1 to OC-12/STM-4c, atm forum pnni 1.0 versions, virtual UNI, per-vc basis queueing form, greater than 1,000,000 cell buffer memory, call setup are less than 2ms, maximum port speed 622Mb/s (OC-12c/STM-4c), Ethernet interface compatibility 802.3, and the RJ-45 connector.

Inverse multiplexer with N*E1 (N=1～4) inverse multiplexing to 1 an E2 interface, can detect channel quality automatically, carries out the speed adjustment automatically.When N (N=1～3) bar E1 circuit was blocked, the service integration that will be blocked circuit automatically was to unbroken circuit.

Video/audio matrix, be supported in the signal of the multiple form in the same rack, digital video, AES/BEU digital audio as analogue audio frequency and video, standard and high definition, be supported in the route between digital audio and analogue audio frequency under the same rank, maximum can be configured to 128 * 128 tunnel independently video or audio unit, or two 64 * 64 road independent videos and audio frequency combination, or the combination of 4 kind of 32 * 32 different-format device.The analog video device comprises 32 road video I/O, and stereo analog audio device provides the processing of stereo audio signal and the output of broadcasting-quality.System's input bandwidth is 100MHz, and input/output interface is 75 Ω BNC, return loss＞40dB DC to10MHz, and analog audio device is the input and output of balance mode, maximum I/O is+24dBu.

The digital special effect cut bank as a multifunctional digital stunt system, can provide the complicated special effects of broadcast level quality, and realization two-channel digital special effects, support SDI, analog component signal and analog mixed-signal, the YUV color correction functions can be provided, adjust white balance and full color.Can select the ratio of width to height of 4:3 or 16:9 picture as required, black synchronizing signal output can be provided, with realize with external equipment synchronously, can carry out frame to picture deposits, and freeze picture in the frame mode, can carry out various special effects processing to prospect or background frame, the technical indicator of signal processing sees the following form:

Sample frequency	Y is 13.5MHz, and R-Y/B-Y is 6.75MHz, and KEY is 13.5MHz
		Quantize	Y/R-Y/B-Y is 8 bits, and KEY is 8 bits
The differential gain	Be less than 3.5% (analog composite input), be less than 2.5% (analogue component input)
		The differential phase	Be less than 2.50 (analog composite outputs), be less than 1.00 (analogue components)
Frequency response	0～5MHz+0.5dB/-1Db
		S/N	Greater than 50dB (analog composite), greater than 55dB (analogue component)
System delay	1 frame

Film titler, PCI32 position bus, high speed picture and text accelerator, 10 digital bits coding, digital 4:2:2 digital processing mode, the output of 32 bitmap literal curtains, 256 grades of transparency settings.Support interface, the built-in time base corrector of integrated circuit board such as compound, Y/C, have the output of compound keys signal.The real-time broadcast all over the screen of three-dimensional animation, a plurality of local animations broadcast simultaneously in real time with screen.Captions broadcast to adopt the possible table mode, can be regularly, manually, time-delay, circulation broadcast animation, captions and the picture and text stunt of any-mode.Standard TrueType character library adopts the anti-aliasing algorithm in captions edge to guarantee that big word is stable level and smooth, and small character is clear not to glimmer.Multiple captions stunt is provided, comprises that wave, scrolling, flag waft, zoom, upset and handwritten word etc., support from wound portrait, portraiture.Bitmap advanced processes device is provided, and built-in multiple filter effect provides the editor and the Chinese WindowsNT operating platform synthetic and specialty of multilayer bitmap.ATL comprises gradual change template, object template, literal template, Materials Library, texture storehouse, light efficiency storehouse, shape library, icon library and context vault etc.

The server of operation application software, CPU is Pentium 42.4G, in save as 512MB, hard disk is 240GB, CD-ROM drive is 54X, operation VCCC (Video Conference Center Control, video conference center control) software.

The terminal of operation application software, CPU is Pentium 42.4G, in save as 512MB, hard disk is 80GB, CD-ROM drive is 54X, operation VCT (Video Conference Terminal, video conference terminal) software.

Application software, it further comprises VCCC and VCT.

The acoustic image transmitting device comprises codec, ATM switch, the inverse multiplexer shared with the broadband videoconference in broadcast level device, and equipment connecting relation is seen Figure 11.

Network administration apparatus comprises codec, ATM switch, the inverse multiplexer shared with acoustic image transmission system device, and the PC terminal of operation VCT (Video Conference Terminal, video conference terminal).Equipment connecting relation is seen Figure 15.

Above system satisfies following the requirement:

(1) the grid center control that forever conducts a meeting;

(2) main meeting-place is different from control centre, and promptly it is not necessarily in the control centre meeting-place;

(3) the various functions of meeting are passed through the manual control realization at center, and easy and simple to handle, step is few, participates in the control personnel and is limited in 2～3 people;

(4) end-to-end time-delay is looked audio sync in 400ms, no relative time delay;

(5) the conference audio service channel is independent of the conference audio system, and Master Control Center can be got in touch with any point, realizes intercommunication, also can send instruction.

With VMCU (Virtual Multiple Control Unit, virtual multipoint control unit) system is that the network configuration of core has realized functions such as conference dispatching and conference control equipment management, and VMCU only operates and control signaling, and does not handle video and voice data.When system will realize certain conference actions, terminal was sent a request to VMCU.Make response by VMCU according to request, and send different instruction control corresponding terminal and initiate a meeting.Because VMCU only carries out the meeting instruction manipulation, therefore shared bandwidth is very little, the problem of nonexistent code stream bottleneck.Figure 9 shows that video conference device composition logic and basic functional principle thereof.

When codec A looked audio frequency for the speech meeting-place and to all the other 4 codecs transmission, the meeting agency who passes through A sent a request to VMCU.VMCU receives reprocessing should request, comprises authentication and could utilize the retrieval etc. of conferencing resource." meeting proxy terminal " given in response of feedback after inquiring about, and whether decision can carry out meeting/look audio transmission.If allow, VMCU returns an information, comprises address, the available resources of other 4 codecs, and when initiates meeting/look audio transmission, and " meeting proxy terminal " initiates action according to these information Control codecs.

When calling out other codecs, VMCU can understand its whole calling procedure at " meeting proxy terminal ".After confirming the accurately punctual foundation of these callings, VMCU will no longer interfere and handle the work between each codec, and remaining work is exactly the carrying out of controlling meeting.Conference process can be carried out the control script in advance, is finished automatically by VMCU.Also can change the process of meeting as required at any time, as B point request floor, the B point becomes key frame and speech etc. after the VMCU permission.

Conference flow under VMCU (Virtual Multiple Control Unit, the virtual multipoint control unit) control mode as shown in figure 10.

The control of meeting process has following two kinds of patterns:

1. chairman's pattern

(1) selects the sub-venue picture

For example, control with chairman's pattern at A meeting-place meeting.The sub-venue seen is wanted in selection, as D, E.Click the icon of D, E, VCT sends an instruction to VCCC.VCCC control video/audio matrix switches to the output in the corresponding A Room with the input of D, E, this moment the A Room large-screen on show the picture of D, E.Available as also having other meeting-place this moment, chairman can click " poll " button, and a time is set, and VCCC regularly can control video/audio matrix switching meeting constantly meeting-place picture,

(2) participant meeting-place request floor

Chairman VCT withdraws from sub-venue request window, if " agreement " button is then clicked in approval.Chairman VCT sends instructions to VCCC, and gating matrix is exported to the meeting-place of request floor the key frame in A meeting-place.Send effect machine to do the synthetic and audio mixing of picture in Chair site and speech meeting-place and the meeting-place of making a speech simultaneously, be broadcast to other sub-venues then,

2. instructor in broadcasting's pattern

(1) beginning meeting

The instructor in broadcasting is gating matrix on VCCC, selects the picture of sub-venue to give A and B, and the picture that control sub-venue picture wheel is inquired about the main meeting-place sends sub-venue to,

(2) participant meeting-place request floor

If " agreements " button is then clicked in approval, key frame to the A/B meeting-place is switched in instructor in broadcasting's gating matrix on VCCC meeting-place of will make a speech, and in maybe will make a speech meeting-place and other sub-venues one synthesizes the key frame of switching to A/B through stunt.The meeting-place of making a speech sees this moment being the main meeting-place picture, and other sub-venues are seen the synthetic picture in main meeting-place and speech meeting-place.

(3) inverse multiplexing of communication line;

(4) by network management information being attached on the acoustic image transport stream or selecting Internet (TCP/IP), the packet switching network (X.25) or switched telephone network communication network transmission network management information such as (SLIP/PPP) for use.

Broadcast level acoustic image transmitting device utilizes existing fiber and SDH/PDH communication network, mainly finishes the broadcast level transfer function of acoustic image, and implementation is illustrated as shown in figure 11.

Wherein each JQ (JQ1～JQ7 is the tier-2 sub-committee field, and JQa is three grades of sub-venues) point is installed row decoder and 1 tunnel up encoding and decoding under 1 tunnel, and compression coding mode is MPEG-2 4:2:2.Codec modules all is contained in the same cabinet, and the atm module in the cabinet is multiplexed into the MPEG-2 code stream of input and output on the multimode fiber light mouth of STM-1 of cabinet.Be access to inverse multiplexer then, be fitted to the G.703 standard interface of 4 E1.Pass through the interface of 4 E1 transmission channels of SDH/PDH like this on the network, and, divide to be clipped to A, B 2 points, thereby realize the transmitted in both directions and the video/audio encoding and decoding function of acoustic image through the switching of C point to C point inverse multiplexer correspondence.The equipment disposition annexation of JQ each point such as Figure 12 and shown in Figure 13.

Aspect clock synchronization, C point and each JQ point can adopt inverse multiplexer based on clock operation itself, also can operational lock in its arbitrarily on E1 circuit.

Aspect the video/audio signal access, the equal timing base of the signal input part adjuster of A, B and JQ1～7 encoders, base function when realizing relatively poor, the off-gauge video of correction quality.The codec aspect is equipped with simulation on request and looks audio interface.A, B and JQ1～7 each points are all joined 10 on request and are selected 1 video switcher and simulation AV distributer, finish the switching in video/audio signal source and select with distribution.

2 of A, B install row decoder and 1 tunnel downlink coding device (compress mode is MPEG-2 4:2:2) on 1 tunnel, and codec modules all is contained in the same cabinet.Atm module in the cabinet is multiplexed into the STM-1 single-mode optics interface of cabinet to the MPEG-2 code stream of input and output, is access to ATM switch then, thereby transfers to the C point by monomode fiber.The ATM switch that process C is ordered exports under the specific inverse multiplexing equipment and passes to each JQ, and the equipment disposition that A, B are ordered connects as shown in figure 14.

The major function that the acoustic image transmitting device is finished is that broadcast type transmission and special project are transmitted two kinds.

Broadcast type transmission promptly from the signal of A, 2 outputs of B respectively timesharing be transferred to all JQ with broadcast mode; Special project is transmitted as from the signal of A, 2 outputs of B can downlink to N JQ (N=1～7) selectively, from the up signal of JQ selectively transmitted in packets to A or B point or be transferred to A, B 2 points simultaneously.

Above equipment constitutes the acoustic image transmitting device, satisfies following system requirements:

(1) the acoustic image transmission quality can satisfy repeatedly editor's needs, and 4:2:2 can be issued to the broadcast level quality 4 editor's situations; 4:2:0 is issued to broadcast level quality (8MB compression) 2 editor's situations;

(2) A, B two places have webmaster minute control function by master control C point;

What (3) each point all possessed expansion looks the audio frequency input/output interface, and concrete number is 10 to go into 8 and go out (simulation);

(4) interface of each JQ point transmission channel all adopts the inverse multiplexing interface equipment to adapt to the SDH/PDH channel requirement that the user proposes;

(5) transmission of 2 of A, B is transferred to the ATM switch that C is ordered by monomode fiber;

(6) inverse multiplexing equipment has the adaptive ability to channel-failures;

(7) end-to-end propagation delay time is less than 400ms;

(8) external standard network interface equipment provides and adds the descrambling interface;

(9) the E3/DS3 interface is all arranged is the interface capability of SDH/PDH to adapt at these 2 to C point channel to 2 atm devices of A, B.

Uploading audio and video information with sub-venue to the main meeting-place is example, and step is as follows:

(1) sub-venue uses the equipment of gathering and editing, and as collection and editing video streams such as video cameras, produces numeral or analog video stream and send codec;

(2) codec send ATM switch with the file of numeral or analog video stream boil down to MPEG-2 form;

(3) ATM switch produces the ATM code stream and send ATM transmission network;

(4) ATM switch of main meeting-place receives the ATM code stream, send codec with its file that reverts to the MPEG-2 form;

(5) file of codec decompression MPEG-2 form is that numeral or analog video stream send the equipment of editing and interviewing;

(6) device processes of editing and interviewing.

The signal of network management device implementation as shown in figure 15.

This device can only be respectively by independent network element such as class timesharing management codec, ATM switch and inverse multiplexers, and equipment control all is through IP tunnel, and the transmission of network management information can be passed through dual mode, and the one, additional mesh tube information on the transport stream of acoustic image net; The 2nd, select Internet (TCP/IP), the packet switching network (X.25) or the switched telephone network special transport network information of communication network such as (SLIP/PPP) for use.The codec of each point all has the function of IP over ATM, can pass through video transmission lines communicating control information.Briefly, pass through a computer, the i.e. all codecs of may command the whole network at the C point.Also can pass through private network, realize the whole network inverse multiplexer such as telephone network etc., even the supervision of ATM switch and control.

From Figure 15 as seen, each point all is furnished with PC terminal and the hub of operation VCT.The controlled device of each point all links to each other with the PC terminal by hub, realizes local control.Can control codec, inverse multiplexer and ATM switch etc. respectively by this system.Connect the PC terminal that each point moves VCT by data communication networks such as telephone network or packet switchinges with dialing or private-line mode simultaneously, form whole webmaster network, realize management and monitoring whole each equipment of transmission system.

Codec is by IP over atm feature, and the management information that superposes on professional transport stream is finished management and monitoring to the codec of far-end by service transmission channels.

For the ease of monitoring the remote equipment in a plurality of places, at master control and branch control center, promptly A, B and C point has disposed router, can realize monitoring and control to the equipment of a plurality of remote location simultaneously on a control terminal.

The network management configuration that A, B are ordered connects as shown in figure 16.

The network management configuration that C is ordered connects as shown in figure 17.

The network management configuration of JQ each point connects as shown in figure 18.

The control PC of each point is installed MS Windows NT Server or Workstation operating system and dialup server software, to respond external dialing.Utilize Modem and telephone network to come transmitting data information.When remote dial, after the dialup server response dialing, long-range user can be under permission browse network, with control and monitor network.

Process based on inverse multiplexing has certain expense, adds that the traffic administration of ATM also needs certain overhead-bits.So when utilizing the inverse multiplexer transmission, the available MPEG-2 code check of codec must be followed following scope.

The E1 number of lines	ATM information source flow	The ATM code check	The highest available MPEG code check
				1	4640	1967360	1700000
2	9280	3934720	3500000
				3	13921	5902504	5300000
4	18561	7869864	7100000
				5	23202	9837648	8900000
6	27842	11805008	10700000
				7	32482	13772368	12500000
8	37123	15740152	14300000

System index is as follows:

(1) coding requirement

Sequence number	Index name	Index request
			(a)	Compression standard	MPEG-2MP@ML4:2:2
(b)	The MPEG-2 code stream	Meet ITU-TH.222 and ISO/IEC13818-1
			(c)	Video coding	Meet ITU-TH.262 and ISO/IEC 13818-2
(d)	Audio coding	Meet ISO/IEC13818-3

(2) look the audio interface requirement

Sequence number	Index name	Index request
			(a)	Input interface
Video	Analog mixed-signal NTSC/PAL 75 Europe BNC
		Audio frequency		Simulation, 600 Europe impedance balances/non-equilibrium
(b)	Output interface
		Video	Analog mixed-signal NTSC/PAL 75 Europe BNC
	Audio frequency			Simulation, 600 Europe impedance balances/non-equilibrium

(3) transmission network index

Sequence number	Index name	Index request
			(a)	Communication interface	G.703、E1、E2、E3、DS3、OC3c/STM-1
(b)	The passage error rate	≤ 10E-7 error rate operate as normal

(4) transmission quality (simulation)

Sequence number	Index name	Index request
			(a)	The output of PAL-D video
The video output amplitude	700mvp-p±20mv
		Synchronous amplitude		300mvp-p±9mv
Band is outer to be disturbed	-40dBm
		Amplitude-frequency characteristic		During≤4.8MHz ± 0.5dB 4.8MHz～5.0MHz, ≤ 0.5dB, 〉=-1.0dB 5.5MHz time-4dB ,+0.5dB

	The K factor	≤3％
			Luminance non-linearity	±5％
	DG	≤5％p-p
			DP	≤5°p-p
	The light tone gain does not wait	±5％
			The light tone time-delay does not wait	≤30ns
	S/N weighted value (5M bandwidth measurement value)	〉=56dB (50% flat field)
			Row synchronous forward position shake	≤20nsp-p
	The transport stream error rate	≤1.0E-11
			(b)	Audio frequency output
Maximum Output Level	+9dBu
		Amplitude-frequency response		20Hz～20kHz±2dB 60Hz～18kHz±0.5dB
Harmonic distortion	≤1％
		Not weighting S/N		≥70dB
Interchannel crosstalk	≤-70dB
		The left and right acoustic channels level difference		60Hz～18kHz≤0.5dB
Interchannel phase difference	60Hz～18kHz≤5°

(8) video conference

Can realize the real time bidirectional transmission;

Can realize satisfying the switching image of teleconference, the function of morbid sound;

Subjective image switching non-jitter, sound and image do not have relative time delay, and end-to-end absolute time delay is within 0.4S.

Other of system require as follows:

(1) index is by the detection of radio and television metering inspection center of State Administration of Radio Film and Television.

(2) can adapt to the development of communication network, the whole network adopts the special line transmission means substantially at present.With the development of communication, native system can adapt to the demand for development of IP and ATM exchange broadband transmission network.

(3) have that total digitalization is switched and the switching disposal ability, can realize that by appropriate reconstruction the whole network looks the Audio Processing digitlization.

(4) network interface available reverse multiplexer or ATM make it have the function of transmitted in both directions multichannel code stream.

(5) have the interface capability of video request program (VOD), implementation method is carried out scrambler for adding conditional access information in the encoder encodes process.The output code flow of encoder is converted to QAM modulation output through interface conversion equipment, sends to the user through transmission network.The user receives by set-top box, finishes descrambling and MPEG-2 decoding, realizes the VOD function.

A kind of acoustic image transmission method of broadband videoconference in broadcast level, the implementation of broadcast level acoustic image transmission is as follows:

Utilize existing fiber and SDH/PDH communication network, finish the broadcast level transfer function of acoustic image, each JQ (JQ1～JQ7 is the tier-2 sub-committee field, and JQa is three grades of sub-venues) point is installed row decoder and 1 tunnel up encoding and decoding under 1 tunnel, and compression coding mode is MPEG-2 4:2:2.Codec modules all is contained in the same cabinet, and the atm module in the cabinet is multiplexed into the MPEG-2 code stream of input and output on the multimode fiber light mouth of STM-1 of cabinet.Be access to inverse multiplexer then, be fitted to the G.703 standard interface of 4 E1.Pass through the interface of 4 E1 transmission channels of SDH/PDH like this on the network, and, divide to be clipped to A, B 2 points, thereby realize the transmitted in both directions and the video/audio encoding and decoding function of acoustic image through the switching of C point to C point inverse multiplexer correspondence,

Aspect clock synchronization, C point and each JQ point can adopt inverse multiplexer based on clock operation itself, also can operational lock in its arbitrarily on E1 circuit,

Aspect the video/audio signal access, the equal timing base of the signal input part adjuster of A, B and JQ1～7 encoders, base function when realizing relatively poor, the off-gauge video of correction quality.Aspect codec, be equipped with simulation on request and look audio interface.A, B and JQ1～7 each points are all joined 10 on request and are selected 1 video switcher and simulation AV distributer, and finish the switching in video/audio signal source and select with distribution,

2 of A, B install row decoder and 1 tunnel downlink coding device (compress mode is MPEG-2 4:2:2) on 1 tunnel.Codec modules all is contained in the same cabinet, and the atm module in the cabinet is multiplexed into the STM-1 single-mode optics interface of cabinet to the MPEG-2 code stream of input and output, is access to ATM switch then, thereby transfers to the C point by monomode fiber.The ATM switch that process C is ordered exports under the specific inverse multiplexing equipment and passes to each JQ, and the equipment disposition that A, B are ordered connects as shown in figure 14.

Broadcast type transmission and two kinds of transmission meanss of special transmission are arranged, the broadcast type transmission promptly from the signal of A, 2 outputs of B respectively timesharing be transferred to all JQ with broadcast mode; Special project is transmitted as from the signal of A, 2 outputs of B can downlink to N JQ (N=1～7) selectively, from the up signal of JQ selectively transmitted in packets to A or B point or be transferred to A, B 2 points simultaneously,

The implementation of network management is as follows: select Internet (TCP/IP), the packet switching network or switched telephone network transmission for use, can transmit or receive network management information through the video transmission lines.Is all codecs of may command the whole network at C o'clock by a computer, also can monitor and control the inverse multiplexer of the whole network by telephone network, or ATM switch;

Each point all is furnished with control with PC and hub, and the controlled device of each point all links to each other with PC by hub and realizes local control, can control codec, inverse multiplexer and ATM switch respectively by this system.Form whole webmaster network by telephone network or packet switched data communication networks with the PC that dialing or private-line mode connect each point simultaneously, realize management and monitoring whole each equipment of transmission system;

Codec is by IP over atm feature, and the management information that superposes on video transmission stream is finished management and monitoring to the codec of far-end by service transmission channels;

For the ease of monitoring the remote equipment in a plurality of places, at master control and branch control center, promptly A, B and C point has disposed router, can realize monitoring and control to the equipment of a plurality of remote location simultaneously on a control terminal.

The acoustic image transmission method of broadband videoconference in broadcast level, its concrete steps are as follows:

(1) with the video/audio signal Real Time Compression is high-quality MPEG-2 video-voice frequency flow;

(2) broadcast level is looked the realization of audio collection, switching and remote switch;

(3) realization of broadband videoconference in broadcast level;

(4) inverse multiplexing of communication line;

(5) by network management information being attached on the acoustic image transport stream or selecting Internet (TCP/IP), the packet switching network (X.25) or switched telephone network communication network transmission network management information such as (SLIP/PPP) for use;

(6) under the Windows system, use Visual C++ high-level language exploitation broadband videoconference in broadcast level and the required all functions of acoustic image transmission.

The acoustic image transmission method of broadband videoconference in broadcast level comprises that also step is as follows:

(1) relies on ATM, SDH and FR/PSTN transmission network;

(2) exploitation VCCC that wants required for the present invention and VCT under Windows operating system;

(3) all functions of realization video conference are looked audio quality and are reached broadcast level;

(4) the realization remote transmission is looked audio frequency, and quality reaches broadcast level.

Description of drawings

Figure 1 shows that system organization schematic diagram of the present invention.

Figure 2 shows that three devices forming system by communication network.

Figure 3 shows that the system equipment connection layout.

Figure 4 shows that video conference device implementation schematic diagram.

Figure 5 shows that ATM switch and coding/decoding apparatus configuration connection diagram that C is ordered.

Figure 6 shows that video and audio equipment configuration connection diagram.

Figure 7 shows that the main meeting-place switches the schematic diagram watch a sub-venue picture by matrix.

Figure 8 shows that the main meeting-place is switched by matrix watches the schematic diagram that participates in dialogue sub-venue picture.

Figure 9 shows that the schematic diagram of video conference device composition logic and basic functional principle thereof.

Figure 10 shows that the conference flow schematic diagram under the VMCU control mode.

Figure 11 shows that broadcast level acoustic image transmitting device implementation schematic diagram.

Figure 12 shows that the schematic diagram of JQ each point equipment disposition annexation.

Figure 13 shows that the schematic diagram of JQ each point equipment disposition annexation.

Figure 14 shows that the schematic diagram that A, the configuration of B point device connect.

Figure 15 shows that the schematic diagram of network administration apparatus implementation.

Figure 16 shows that the network management configuration connection diagram that A, B are ordered.

Figure 17 shows that the network management configuration connection diagram that C is ordered.

Figure 18 shows that the network management configuration connection diagram of JQ each point.

Figure 19 shows that acoustic image transmitting device workflow schematic diagram.

Embodiment

Figure 1 shows that the acoustic image transmission system figure of broadband videoconference in broadcast level of the present invention.

The acoustic image transmission system of broadband videoconference in broadcast level, comprise broadband videoconference in broadcast level device, acoustic image transmitting device and three devices of network administration apparatus, communication network, and the system integration technology, all devices and the application software that realize systemic-function, broadband videoconference in broadcast level device, acoustic image transmitting device and network administration apparatus are realized interconnected by communication network.

Figure 2 shows that the tissue signal of DELTA broadband videoconference in broadcast level of the present invention and acoustic image transmission system, wherein utilize the existing communication network, with the control centre of C point as video conference and acoustic image transmission, with other places 7 points (JQ1～7), local 11 point (A～B, D～G, G1～G4) are example, and the present invention is the main function that realizes broadcast level video conference and acoustic image transmission on the basis of network management.A, B, D, E, F, G point (tier-2 sub-committee field), C point (meeting-place, center).

Figure 3 shows that equipment of the present invention connects signal.Main meeting-place (main meeting-place during holding video conference) comprising: film titler 1, effect machine 2, monitor 3, video source 4, video/audio matrix 5, video tape recorder 6, codec 7, HUB (hub) 8, webmaster main meeting-place 9, ATM switch 10, router one 1 and inverse multiplexer 12.The equipment that sub-venue (sub-venue during holding video conference) comprises has lacked film titler, effect machine, video/audio matrix and ATM switch than the main meeting-place, and the webmaster main meeting-place becomes the webmaster sub-venue.

Film titler and effect machine are used to the monitor content displayed to add captions and stunt, and monitor is used to show the image of main meeting-place (main meeting-place), and video/audio matrix control I/O is which video information, and video tape recorder is used to provide or recording video information.Codec is used for compression (passing down) and decompress (the uploaded videos information of reception), the equipment needed thereby that HUB is used to connect main meeting-place (main meeting-place) is a local area network (LAN), the webmaster main meeting-place is used to control the relevant devices of sub-venue (sub-venue), ATM switch is used for the video file after the compression become behind the ATM code stream and passes down, perhaps receives the video file that becomes behind the ATM code stream of uploading after the compression and send codec to decompress.Router is used for the webmaster main meeting-place and selects route, and inverse multiplexer receives the ATM code stream and also is multiplexed into 4 E1 circuits, and perhaps the information that 4 E1 circuits are uploaded becomes an ATM code stream and send ATM switch.

Figure 4 shows that the signal of video conference device implementation.

The C point can minute two parts be resolved, and promptly atm line controlling equipment and meeting are used looks the audio frequency switched system, and meeting line arrangement equipment is mainly realized with ATM switch.

The local code stream that C is ordered is adjustable spends each JQ, and PDH/SDH coffret equipment adopts the inverse multiplexer of 4 road E1 (2Mb/s).This scheduling can be a broadcast type, and promptly all JQ watch the situation that the C point is local simultaneously, and perhaps only some JQ can watch.The Control Software of ATM switch has a routing table, and the user can correctly be dispatched to C point code stream on the JQ point of appointment in this table on request.

7 road code streams of coming from each JQ passback can all be sent to the decoder that C is ordered, thereby decode video/audio signal, send into matrix and sound console and dispatch with stunt and handle.

On the other hand, the code stream that JQ1～7 biography is come becomes SDI video and analogue audio frequency through behind the decoder.This 7 tunnel vision signal is sent to 7 cover frame synchronization module, then the supervision sub-module is delivered in its output synchronously.This module can be distributed SDI, and 4 road SDI are provided output, to satisfy the requirement of data monitor from now on, can provide 4 road analog mixed-signals to monitor and the input of analog video switching matrix simultaneously.This 7 road JQ image adds that 3 tunnel local signal sources of C point all lead to 32 * 16 matrixes, and this matrix can expand to 64 * 64.Effect machine is led in wherein 4 tunnel outputs of matrix, sends matrix back to through loop then.No. 2 encoders are led in other 2 tunnel outputs.The standard sync signal of synchronous generator output produces 15 the road through 8801 video distribution amplifiers and exports synchronously, is used for the synchronously external decoded signal of C point, video matrix, effect machine and local program source, reaches the effect that matrix switches non-jitter.

The configuration of the ATM switch that Fig. 5 and C respectively shown in Figure 6 are ordered and coding/decoding apparatus is connected and looks audio configuration and be connected signal.

Operator scheme only need can realize whole meeting with two encoders, and wherein No. one encoder is arranged to the main meeting-place, and arrange to all sub-venues on another road.When make a speech in the main meeting-place, all sub-venues are watched the picture of main meeting-place.

Figure 7 shows that the main meeting-place switches the picture watch any sub-venue by matrix.

Codec #1 mainly act as when main meeting-place during not at the C point, and the ATM switch that needs utilize codec #1 and C to order under the help that C is ordered is dispatched appropriate signals for the main meeting-place.At the C point,, and directly utilize the matrix scheduling signals as the main meeting-place then without codec #1.

Figure 8 shows that the main meeting-place switches the stunt picture watch these two sub-venues dialogues by matrix.

The position of main meeting-place is unimportant, because picture and operation are simplified, but the permanent the driver's seat that C is ordered is constant.

With the VMCU system is that the network configuration of core has realized functions such as conference dispatching and conference control equipment management, and VMCU only operates and control signaling, and does not handle video and voice data.When system will realize certain conference actions, terminal was sent a request to VMCU.Make corresponding reaction by VMCU according to request, and send different instruction control relevant terminal and initiate a meeting.Because VMCU only carries out the meeting instruction manipulation, therefore shared bandwidth is very little, the problem of nonexistent code stream bottleneck.

Figure 9 shows that video conference device composition logic and basic functional principle thereof.

When codec A looked audio frequency for the speech meeting-place and to all the other 4 codecs transmission, the meeting agency who passes through A sent a request to VMCU.VMCU receives reprocessing should request, comprises authentication and could utilize the retrieval etc. of conferencing resource." meeting proxy terminal " given in response of feedback after inquiring about, and whether decision can be transmitted and look audio frequency.If allow, VMCU returns an information, comprises address, the available resources of other 4 codecs, and when initiates meeting or look audio transmission, and " meeting proxy terminal " initiates action according to these information Control codecs.

When calling out other codecs, VMCU can understand its whole calling procedure at " meeting proxy terminal ".After confirming the accurately punctual foundation of these callings, VMCU will no longer interfere and handle the work between each codec, and remaining work is exactly the carrying out of controlling meeting.Conference process can be carried out the control script in advance, is finished automatically by VMCU.Also can change the process of meeting as required at any time, as B point request floor, the B point becomes key frame and speech etc. after the VMCU permission.

Conferencing streams under the VMCU control mode shown in Figure 10, its step is as follows:

S10-1: main meeting-place operation VCCC, initialization relevant devices;

S10-2: sub-venue operation VCT, initialization relevant devices;

S10-3: the main meeting-place issues notice of meeting or sub-venue preset conference, issues notice of meeting after the VCCC audit;

S10-4:VCT judges whether to receive notice of meeting message;

S10-5: do not receive, then can click the inquiry of " obtaining inquiry " button and have or not meeting;

S10-6: receive notice of meeting message, click " login " button and connect main meeting-place VCCC, send logging request;

S10-7:, click " beginning meeting " button response meeting-place logging request and carry out authentication to the meeting time;

S10-8: connect normally, VCT shows current topo graph, connection status and Session Topic;

S10-9: connect normally, VCCC shows current topo graph, connection status and Session Topic;

S10-10: enter the control of meeting process, distinguish main meeting-place and sub-venue; Chairman has the authority in control meeting-place, as handling speech application etc.

Figure 11 shows that broadcast level acoustic image transmitting device comprises codec, ATM switch, the inverse multiplexer shared with the broadband videoconference in broadcast level device, broadcast level acoustic image transmitting device utilizes existing fiber and SDH/PDH communication network to finish the implementation signal of acoustic image broadcast level transfer function.Wherein, codec is connected with the ATM switch of A, B, D, E, F, G point (tier-2 sub-committee field), the ATM switch that A, B, D, E, F, G are ordered is connected with inverse multiplexer by the ATM switch of optical fiber with C point (meeting-place, center), and the uplink and downlink circuit by the SDH/PDH communication network is connected with the codec and the inverse multiplexer of each sub-venue then.

Figure 12 and the equipment disposition that is respectively the JQ each point shown in Figure 13 connect signal, and each JQ point is installed row decoder and 1 tunnel up encoding and decoding under 1 tunnel, and compression coding mode is MPEG-2 4:2:2.Codec modules all is contained in the same cabinet, and atm module wherein is multiplexed into the MPEG-2 code stream of input and output on the multimode fiber light mouth of STM-1 of cabinet.Be access to inverse multiplexer then, be fitted to the G.703 standard interface of 4 E1.Pass through the interface of 4 E1 transmission channels of SDH/PDH like this on the network to C point inverse multiplexer correspondence.And, divide to be clipped to A, B 2 points, thereby realize the transmitted in both directions and the video/audio encoding and decoding function of acoustic image through the switching of C point.

Aspect clock synchronization, C point and each JQ point can adopt inverse multiplexer based on clock operation itself, also can operational lock in its arbitrarily on E1 circuit.

Aspect the video/audio signal access, the equal timing base of the signal input part adjuster of A, B and JQ1～7 encoders, base function when realizing relatively poor, the off-gauge video of correction quality.The codec aspect is equipped with simulation on request and looks audio interface.A, B and JQ1～7 each points are all joined 10 on request and are selected 1 video switcher and simulation AV distributer, finish the switching in video/audio signal source and select with distribution.

Figure 14 shows that the equipment disposition that A, B are ordered connects signal, two points are all installed row decoder and 1 tunnel downlink coding device (compress mode is MPEG-2 4:2:2) on 1 tunnel.Codec modules all is contained in the same cabinet.Atm module in the cabinet is multiplexed into the STM-1 single-mode optics interface of cabinet to the MPEG-2 code stream of input and output, is access to ATM switch then, thereby transfers to the C point by monomode fiber.The ATM switch of ordering through C at the C point exports under the specific inverse multiplexing equipment and passes to each JQ.

The major function that the acoustic image transmitting device is finished is that broadcast type transmission and special project are transmitted two kinds.

Broadcast type transmission promptly from the signal of A, 2 outputs of B respectively timesharing be transferred to all JQ with broadcast mode, special project is transmitted as from the signal of A, 2 outputs of B can selectively downlink to N JQ (N=1～7).From the up signal of JQ selectively transmitted in packets to A or B point or be transferred to A, B 2 points simultaneously.

Figure 15 shows that the signal of network management device implementation.

This device can only be respectively by independent network element such as class timesharing management codec, ATM switch and inverse multiplexers, and equipment control all is through IP tunnel, and the transmission of network management information can be passed through dual mode, and the one, additional mesh tube information on the transport stream of acoustic image net; The 2nd, select Internet (TCP/IP), the packet switching network (X.25) or the switched telephone network special transport network information of communication network such as (SLIP/PPP) for use.The codec of each point all has the function of IP over ATM, can pass through video transmission lines communicating control information.Briefly, pass through a computer, the i.e. all codecs of may command the whole network at the C point.Also can realize the whole network inverse multiplexer by private network such as telephone network etc., even the supervision of ATM switch and control.

From Figure 15 as seen, each point all is furnished with control with PC and hub.The controlled device of each point all links to each other with PC by hub, realizes local control.Can control codec, inverse multiplexer and ATM switch etc. respectively by this system.By the PC of data communication networks such as telephone network or packet switching, form whole webmaster network simultaneously, realize management and monitoring whole each equipment of transmission system with dialing or private-line mode connection each point.

Codec is by IP over atm feature, and the management information that superposes on professional transport stream is finished management and monitoring to the codec of far-end by service transmission channels.

For the ease of monitoring the remote equipment in a plurality of places, at master control and branch control center, promptly A, B and C point has disposed router, can realize monitoring and control to the equipment of a plurality of remote location simultaneously on a control terminal.

Figure 16 shows that the network management configuration that A, B are ordered connects signal.

Figure 17 shows that the network management configuration that C is ordered connects signal.

The network management configuration that Figure 19 shows that the JQ each point connects signal.

The control PC of each point is installed MS Windows NT Server or Workstation operating system and dialup server software, to respond external dialing.Utilize Modem and telephone network to come transmitting data information.When remote dial, after the dialup server response dialing, long-range user can be under permission browse network, with control and monitor network.

Figure 19 shows that the workflow signal of acoustic image transmitting device, its step following (is example with transaudient picture under the main meeting-place):

Transaudient picture concrete steps are as follows under the main meeting-place:

S19-1: the equipment of gathering and editing is used in the main meeting-place, as collection and editing video streams such as video cameras, produces numeral or analog video stream and send codec;

S19-2: codec send ATM switch with the file of numeral or analog video stream boil down to MPEG-2 form;

The S19-3:ATM switch produces the ATM code stream and send ATM transmission network;

S19-4: the ATM switch of sub-venue receives the ATM code stream, send codec with its file that reverts to the MPEG-2 form;

S19-5: the file of codec decompression MPEG-2 form is that numeral or analog video stream send the equipment of editing and interviewing;

S19-6: the device processes of editing and interviewing.

Claims (18)

1. the acoustic image transmission system of a broadband videoconference in broadcast level, it is characterized in that, comprise broadband videoconference in broadcast level device, acoustic image transmitting device and three devices of network administration apparatus, all devices and application software, broadband videoconference in broadcast level device, acoustic image transmitting device and network administration apparatus are by communication network and realize that the system integration technology of systemic-function realizes interconnected.

2. according to the acoustic image transmission system of the broadband videoconference in broadcast level of claim 1, it is characterized in that, the capital equipment that the broadband video conference device comprises is codec, ATM switch, inverse multiplexer, video/audio matrix, digital special effect cut bank, film titler, and the server and the terminal of operation application software.

3. according to the acoustic image transmission system of the broadband videoconference in broadcast level of claim 2, it is characterized in that, the encoder of codec is the MPEG-2 video-voice frequency flow with the video/audio signal Real Time Compression, the video I/O can be selected serial digital interface or PAL/NTSC composite signal, support main profile at main level and the 4:2:2MP@MLM form of MPEG-2, Audio Processing is non-compression of SMPTE 302M and MPEG-1 Layer II form, be provided for the output interface and the atm network interface that is used to be connected ATM of the DVB/ASI of satellite transmission, decoder decompression MPEG-2 video-voice frequency flow, transmit high-quality and real-time MPEG-2 digital video signal to provide, coded format and video bitrate comprise MPEG-1, MPEG-2MP@ML and MPEG-2 4:2:2P@ML.

4. according to the acoustic image transmission system of the broadband videoconference in broadcast level of claim 2, it is characterized in that, ATM switch, 2.5Gb/s the unblock exchange capacity of～10Gb/s, the LAN of complete series and wan interface, port type from T1/E1 to OC-12/STM-4c, atm forum pnni 1.0 versions, virtual UNI, per-vc basis queueing form, greater than 1,000,000 cell buffer memory, call setup are less than 2ms, maximum port speed 622Mb/s, Ethernet interface compatibility 802.3, and the RJ-45 connector.

5. according to the acoustic image transmission system of the broadband videoconference in broadcast level of claim 2, it is characterized in that, inverse multiplexer, with N*E1 inverse multiplexing to 1 an E2 interface, can detect channel quality automatically, automatically carry out the speed adjustment, when N bar E1 circuit was blocked, the service integration that will be blocked circuit automatically was to unbroken circuit.

6. according to the acoustic image transmission system of the broadband videoconference in broadcast level of claim 2, it is characterized in that, video/audio matrix is supported in the signal of the multiple form in the same rack, as analogue audio frequency and video, the digital video of standard and high definition, the AES/BEU digital audio, be supported in the route between digital audio and analogue audio frequency under the same rank, maximum can be configured to 128 * 128 tunnel independently video or audio units, or two 64 * 64 road independent videos and audio frequency combination, or the combination of 4 kind of 32 * 32 different-format device, the analog video device comprises 32 road video I/O, stereo analog audio device provides the processing of stereo audio signal and the output of broadcasting-quality, system's input bandwidth is 100MHz, input/output interface is 75 Ω BNC, return loss＞40dB DC to10MHz, analog audio device is the I/O of balance mode, and maximum I/O is+24dBu.

7. according to the acoustic image transmission system of the broadband videoconference in broadcast level of claim 2, it is characterized in that, the digital special effect cut bank, as a multifunctional digital stunt system, support SDI, analog component signal and analog mixed-signal, the YUV color correction functions can be provided, adjust white balance and full color, can select as required 4: 3 or the ratio of width to height of 16: 9 pictures, black synchronizing signal output can be provided, with realize with external equipment synchronously, can carry out frame to picture and deposit, and freeze picture in the frame mode.

8. according to the acoustic image transmission system of the broadband videoconference in broadcast level of claim 2, it is characterized in that, film titler is a PCI32 position bus, high speed picture and text accelerator, 10 digital bits coding, digital 4:2:2 digital processing mode, the output of 32 bitmap literal curtains, 256 grades of transparency settings, support compound, interfaces such as Y/C, the built-in time base corrector of integrated circuit board, has the output of compound keys signal, the real-time broadcast all over the screen of three-dimensional animation, a plurality of local animations broadcast simultaneously in real time with screen, captions broadcast the possible table mode that adopts, can be regularly, manually, time-delay, the animation of any-mode is broadcasted in circulation, captions and picture and text stunt, standard TrueType character library, adopt the anti-aliasing algorithm in captions edge to guarantee that big word is stable level and smooth, small character is clear not to glimmer, multiple captions stunt is provided, comprise wave, scrolling, flag wafts, zoom, upset and handwritten word, support from the wound portrait, portraiture, bitmap advanced processes device is provided, built-in multiple filter effect, the editor and the Chinese Windows NT operating platform synthetic and specialty of multilayer bitmap are provided, and ATL comprises the gradual change template, object template, the literal template, Materials Library, the texture storehouse, the light efficiency storehouse, shape library, icon library and context vault.

9. according to the acoustic image transmission system of the broadband videoconference in broadcast level of claim 2, it is characterized in that, the server of operation application software, CPU is Pentium 4 2.4GMHz, in save as 512MB, hard disk is 240GB, CD-ROM drive is 54X, operation VCCC software.

10. according to the acoustic image transmission system of the broadband videoconference in broadcast level of claim 2, it is characterized in that, the terminal of operation application software, CPU is Pentium4 2.4GMHz, in save as 512MB, hard disk is 80GB, CD-ROM drive is 54X, operation VCT software.

11. acoustic image transmission system according to the broadband videoconference in broadcast level of claim 1, it is characterized in that, the broadband videoconference in broadcast level device comprises codec, ATM switch, the inverse multiplexer shared with the acoustic image transmitting device, wherein, codec is connected with the ATM switch that A, B, D, E, F, G are ordered, the ATM switch that A, B, D, E, F, G are ordered is connected with inverse multiplexer with the ATM switch that C is ordered by optical fiber, and the uplink and downlink circuit by the SDH/PDH communication network is connected with the codec and the inverse multiplexer of each sub-venue then.

12. acoustic image transmission system according to the broadband videoconference in broadcast level of claim 1, it is characterized in that, network administration apparatus comprises and the shared codec of acoustic image transmission system device, ATM switch, inverse multiplexer, and the PC terminal of operation VCT, each point all is furnished with PC terminal and the hub of operation VCT, the controlled device of each point all links to each other with the PC terminal by hub and realizes local control, can control codec respectively by this system, inverse multiplexer and ATM switch, form whole webmaster network by telephone network or packet switched data communication networks with the PC terminal that dialing or private-line mode connect each point operation VCT simultaneously, realize management and monitoring whole each equipment of transmission system.

13. acoustic image transmission system according to the broadband videoconference in broadcast level of claim 12, it is characterized in that, network administration apparatus, implementation is transmitted specially for selecting Internet (TCP/IP), the packet switching network or switched telephone network communication network for use, the codec of each point all has IP over ATM, can transmit or receive network management information through the video transmission lines, briefly, pass through a computer at the C point, be all codecs of may command the whole network, also can monitor and control the inverse multiplexer of the whole network by telephone network, or ATM switch;

Each point all is furnished with PC terminal and the hub of operation VCT, the controlled device of each point all links to each other with the PC terminal by hub, realize local control, can control codec, inverse multiplexer and ATM switch respectively by this system, the PC terminal that connects each point simultaneously by data communication networks such as telephone network or packet switchinges with dialing or private-line mode, form whole webmaster network, realize management and monitoring whole each equipment of transmission system;

Codec is by IP over ATM, and the management information that superposes on video transmission stream is finished management and monitoring to the codec of far-end by service transmission channels;

For the ease of monitoring the remote equipment in a plurality of places, at central station and substation, promptly C point and A, B point have disposed router, can realize monitoring and control to the equipment of a plurality of remote location simultaneously on a control terminal.

14. the acoustic image transmission method of a broadband videoconference in broadcast level, the implementation of broadcast level acoustic image transmission is as follows:

Utilize existing fiber and SDH/PDH communication network, finish the broadcast level transmission of acoustic image, each JQ point is installed row decoder and 1 tunnel up encoding and decoding under 1 tunnel, compression coding mode is MPEG-24:2:2, codec modules all is contained in the same cabinet, atm module in the cabinet is multiplexed into the MPEG-2 code stream of input and output on the multimode fiber light mouth of STM-1 of cabinet, be access to inverse multiplexer then, be fitted to the G.703 standard interface of 4 E1, pass through the interface of 4 E1 transmission channels of SDH/PDH like this on the network to C point inverse multiplexer correspondence, and minute be clipped to A through C point switching, B 2 points, thereby the transmitted in both directions and the video/audio encoding and decoding of realization acoustic image

Aspect clock synchronization, C point and each JQ point can adopt inverse multiplexer based on clock operation itself, also can operational lock in its arbitrarily on E1 circuit,

Aspect the video/audio signal access, the equal timing base of the signal input part adjuster of A, B and JQ1～7 encoders, base function when realizing relatively poor, the off-gauge video of correction quality; Aspect codec, be equipped with simulation on request and look audio interface, A, B and JQ1～7 each points are all joined 10 on request and are selected 1 video switcher and simulation AV distributer, and finish the switching in video/audio signal source and select with distribution,

2 of A, B install row decoder and 1 tunnel downlink coding device on 1 tunnel, codec modules all is contained in the same cabinet, atm module in the cabinet is multiplexed into the MPEG-2 code stream of input and output the STM-1 single-mode optics interface of cabinet, be access to ATM switch then, thereby transfer to the C point by monomode fiber, the ATM switch that process C is ordered exports under the specific inverse multiplexing equipment and passes to each JQ, the equipment disposition that A, B are ordered

Broadcast type transmission and two kinds of transmission meanss of special transmission are arranged, the broadcast type transmission promptly from the signal of A, 2 outputs of B respectively timesharing be transferred to all JQ with broadcast mode; Special project is transmitted as from the signal of A, 2 outputs of B can downlink to N JQ selectively, from the up signal of JQ selectively transmitted in packets to A or B point or be transferred to A, B 2 points simultaneously,

The implementation of network management is as follows: select Internet (TCP/IP), the packet switching network or switched telephone network transmission for use, can transmit or receive network management information through the video transmission lines, is all codecs of may command the whole network at C o'clock by a computer, also can monitor and control the inverse multiplexer of the whole network by telephone network, or ATM switch

Each point all is furnished with control with PC and hub, the controlled device of each point all links to each other with PC by hub and realizes local control, can control codec, inverse multiplexer and ATM switch respectively by this system, form whole webmaster network by telephone network or packet switched data communication networks with the PC that dialing or private-line mode connect each point simultaneously, realize management and monitoring whole each equipment of transmission system.

15. according to the acoustic image transmission method of the broadband videoconference in broadcast level of claim 14, its concrete steps are as follows:

(1) with the video/audio signal Real Time Compression is high-quality MPEG-2 video-voice frequency flow;

(2) broadcast level is looked the realization of audio collection, switching and remote switch;

(3) realization of broadband videoconference in broadcast level;

VMCU is responsible for conference dispatching and equipment control, and it provides two kinds of conference models:

1. chairman's pattern

(1) selects the sub-venue picture

At A meeting-place meeting,, select to want the sub-venue of seeing with chairman control, D, E, click the icon of D, E, VCT sends an instruction to VCCC, and VCCC control video/audio matrix switches to the input of D, E the output in the corresponding A Room, the picture that shows D, E at this moment on the large-screen in the A Room, available as also having other meeting-place this moment, chairman can click " poll " button, and a time is set, VCCC can constantly switch based on this time timing controlled video/audio matrix can the meeting-place picture

(2) participant meeting-place request floor

Chairman VCT withdraws from sub-venue request window, if approval, then click " agreement " button, chairman VCT sends instructions to VCCC, gating matrix is exported to the meeting-place of request floor the key frame in A meeting-place, send effect machine to do the synthetic and audio mixing of picture in Chair site and speech meeting-place and the meeting-place of making a speech simultaneously, be broadcast to other sub-venues then

2. instructor in broadcasting's pattern

(1) beginning meeting

The instructor in broadcasting is gating matrix on VCCC, selects the picture of sub-venue to give A and B, and the picture that control sub-venue picture wheel is inquired about the main meeting-place sends sub-venue to,

(2) participant meeting-place request floor

If approval, then click " agreement " button, key frame to the A/B meeting-place is switched in instructor in broadcasting's gating matrix on VCCC meeting-place of will making a speech, maybe will make a speech in meeting-place and other sub-venues one through the synthetic key frame of giving A/B that switches of stunt, the meeting-place of making a speech sees this moment being the main meeting-place picture, other sub-venues are seen the synthetic picture in main meeting-place and speech meeting-place

(3) inverse multiplexing of communication line;

(4) by network management information being attached on the acoustic image transport stream or selecting Internet (TCP/IP), the packet switching network or switched telephone network communication network transmission network management information for use.

16. the acoustic image transmission method according to the broadband videoconference in broadcast level of claim 14 comprises that also step is as follows:

(1) relies on ATM, SDH and FR/PSTN transmission network;

(2) exploitation VCCC that wants required for the present invention and VCT under Windows operating system;

(3) all functions of realization video conference are looked audio quality and are reached broadcast level;

(4) the realization remote transmission is looked audio frequency, and quality reaches broadcast level.

17. according to the acoustic image transmission method of the broadband videoconference in broadcast level of claim 15, its step is as follows under the VMCU control mode:

S10-1: main meeting-place operation VCCC, definition meeting place name and initialization relevant devices;

S10-2: sub-venue operation VCT, initialization relevant devices;

S10-3: the main meeting-place issues notice of meeting or sub-venue preset conference, issues notice of meeting after the VCCC audit;

S10-4:VCT judges whether to receive notice of meeting message;

S10-5: do not receive, then can click the inquiry of " obtaining inquiry " button and have or not meeting;

S10-6: receive notice of meeting message, click " login " button and connect main meeting-place VCCC, send logging request;

S10-7:, click " beginning meeting " button response meeting-place logging request and carry out authentication to the meeting time;

S10-8: connect normally, VCT shows current topo graph, connection status and Session Topic;

S10-9: connect normally, VCCC shows current topo graph, connection status and Session Topic;

S10-10: enter the control of meeting process, distinguish main meeting-place and sub-venue; Chairman has the authority in control meeting-place.

18. according to the acoustic image transmission method of the broadband videoconference in broadcast level of claim 15, transaudient picture concrete steps are as follows under the main meeting-place:

S19-1: the equipment of gathering and editing is used in the main meeting-place, gathers and editing video stream, produces numeral or analog video stream and send codec;

S19-2: codec send ATM switch with the file of numeral or analog video stream boil down to MPEG-2 form;

The S19-3:ATM switch produces the ATM code stream and send ATM transmission network;

S19-4: the ATM switch of sub-venue receives the ATM code stream, send codec with its file that reverts to the MPEG-2 form;

S19-5: the file of codec decompression MPEG-2 form is that numeral or analog video stream send the equipment of editing and interviewing;

S19-6: the device processes of editing and interviewing.

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