Defective at above-mentioned prior art, the objective of the invention is to propose a kind of method that in the system that supports two-level concatenation, realizes MCU cascade more than three grades or three grades, by the subnet of MCU more than three grades or three grades and terminal composition thereof is write terminal iidentification T number certainly, with virtual terminal, and realized MCU cascade more than three grades and three grades as higher level's multipoint control unit.
The present invention is achieved by the following technical solution: promptly
A kind of method that in the system that supports two-level concatenation, realizes multipoint control unit cascade more than three grades or three grades, comprise following processing: multipoint control unit more than three grades or three grades and terminal thereof are write terminal iidentification T number certainly, as the virtual terminal of higher level's multipoint control unit; This is set up when communicate by letter as virtual terminal multipoint control unit and terminal thereof and higher level's multipoint control unit, and filtering should be as the multipoint control unit of virtual terminal Bit-rate Allocation Signal signaling to this higher level's multipoint control unit transmission; Increase to send whether effective audio frequency is indicated activation command to the expression audio signal of multipoint control unit transmission as terminal, be used to respond the instruction of this higher level's multipoint control unit.
Described method, also comprise:, further judge this order and comprised sign MT number whether be actual MT number of MCU institute connecting terminal in the virtual terminal if higher level's control unit of the multipoint control unit of oriented this virtual terminal sends video control broadcasting (VCB) order; If, change that this video control broadcasting (VCB) order comprised MT number for virtual terminal MT number.
This virtual terminal multipoint control unit is using in the ini file a self-defined virtual identifying M number in the described method, and this virtual identifying M number is greater than M number of all higher level's multipoint control units.
In the described method M number of this virtual terminal multipoint control unit and subordinate in 75.
Described method also comprises: if this virtual terminal is received the video indication activation command that its higher level's multipoint control unit is sent, the video source that all of the port except that higher level's port of this multipoint control unit is set is higher level's port.
Described method, also comprise: if this virtual terminal is received the video indication number order that its higher level's multipoint control unit is sent, whether further judge this order and comprised sign MT number be MT number of virtual terminal, if, change the terminal that reports for video source in this virtual terminal for this virtual MT number actual MT number.
Described method also comprises: if this virtual terminal is received terminal control string identification (TCS2) order that its higher level's multipoint control unit is sent, to this higher level's multipoint control unit transmission information indication string command (IIS), report virtual terminal meeting-place name.
Described method also comprises: if this virtual terminal is received the terminal indication list commands that its higher level's multipoint control unit is sent, remove virtual MT number in this order, and be transmitted to the port under this virtual terminal multipoint control unit.
Described method also comprises: if this virtual terminal is received the terminal indication assignment commands that its higher level's multipoint control unit is sent, filter this order, continue to use this virtual MT number.
Described method, also comprise: indicate visual order if this virtual terminal is received the multiple spot that its higher level's multipoint control unit is sent, the video source of the multipoint control unit operating desk designated port of virtual terminal is switched the port to the higher level, and send the multiple spot virtual terminal indication of expansion BAS signaling to this designated port.
Described method, also comprise: indicate visual order if this virtual terminal is received the cancellation multiple spot that its higher level's multipoint control unit is sent, the video source of all of the port except that higher level's port of this multipoint control unit recovers to be set to higher level's port, and reports port to send the cancellation multiple spot virtual terminal indication of extended bit rate distributing signal signaling to former video source.
Described method comprises that also this virtual terminal is transmitted this order to its higher level's multipoint control unit if this virtual terminal is received the audio frequency indication activation command of its port at the corresponding levels.
Described method comprises that also this virtual terminal sends terminal indication to its subordinate multipoint control unit and distributes (TIA) order, distributes sign M number of subordinate's multipoint control unit this virtual terminal under and adds one again for MCU at the corresponding levels number and port numbers sum.
According to technical scheme of the present invention, be the terminal that terminal or subnet virtualization with MCU and connection thereof become higher level MCU, therefore, this MCU has two critical functions, and concerning higher level MCU, it is a terminal, concerning the MCU of the terminal of the corresponding levels or subordinate, it is a MCU.Therefore, claim this MCU to be " virtual terminal ".The present invention is by carrying out filtration treatment to Bit-rate Allocation Signal (BAS) signaling that sends between itself and the higher level MCU on the MCU, its BAS signaling that sends to higher level MCU as MCU of filtering, only send the BAS signaling that MCU, terminal send, and increase the BAS signaling of having only terminal just to send, simultaneously for making terminal under non-" virtual terminal " MCU can control the video camera of each terminal under " virtual terminal " MCU, increased the special viewed terminal of BAS signaling be in video camera can be by the far-end state of a control.Therefore, after adopting method of the present invention, TV conference system can realize three-stage cascade and the cascade more than three grades under the MCU that does not support three-stage cascade decides the situation of MCU, and the quality of image and sound does not descend, terminal under non-" virtual terminal " MCU can be controlled the video camera of terminal under " virtual terminal " MCU, and vice versa.
In sum, the invention solves present TV conference system MCU cascade can not be above the restriction of two-stage, realized following the H.243 cascade of MCU more than three grades and three grades of standard of ITU_T, particularly under the situation of existing two-stage cascade MCU, insert third level MCU even fourth stage MCU, enlarged networking capability, image, the sound quality of having avoided analog switching to bring descends and the control complicated problems.
By description, will make technique scheme of the present invention and advantage apparent below in conjunction with accompanying drawing to preferred embodiment of the present invention.In the accompanying drawing,
Hereinafter will describe the present invention in detail.
Virtual terminal of the present invention system is illustrated among Fig. 2, promptly at first a main MCU and some terminals of connecing down thereof is invented a terminal, is connected under the secondary MCU, thereby can realizes the cascade of the MCU more than three grades or three grades; Thus, this virtual terminal need be write a virtual terminal sign T number certainly.Realize that the virtual terminal technology mainly is the processing procedure of BAS signaling is controlled and revised, its processing procedure is illustrated among Fig. 3.
The BAS sign indicating number that virtual terminal MCU sends to higher level MCU
Under the normal condition by having to the BAS signaling that main MCU sends from MCU: multiple spot indication visual (MIV), multiple spot control meeting (MCC), multiple spot control symmetric data transmit (MCS), multiple spot indication zero communication (MIZ), multiple spot indication secondary state (MIS), multiple spot indication loopback (MIL), terminal indication numbering (TIN), (TID), terminal indication tabulation (TIL), video indication numbering (VIN) are fallen down in the terminal indication." virtual terminal " MCU does not send these BAS orders to higher level MCU.
Because terminal can send AIA to MCU, whether the expression audio signal is effective, so " virtual terminal " MCU increases the transmission that the video indication activates (AIA) order.
Therefore, if system judges at step S200 whether signaling sends the BAS signaling to the higher level MCU of " virtual terminal ", if, then system further judges whether that at step S202 this sets up when communicating by letter as virtual terminal MCU and higher level MCU, has sent this MIV, MCC, MCS, MIZ, MIS, MIL, TIN, TID, TIL, VIN to this higher level MCU.If " virtual terminal " MCU does the processing of step S204, it is filtered out, do not send these BAS orders to higher level MCU.
Simultaneously, the processing of step S206 also will be done by system, if promptly higher level's control unit of the multipoint control unit of oriented this virtual terminal sends video control broadcasting (VCB) order, whether be actual MT number of MCU institute connecting terminal in the virtual terminal further step S208 judge that this order comprises sign MT number; If, execution in step S210 then, MT number that this video control broadcasting (VCB) order is comprised is converted to MT number of virtual terminal.
In addition, the MCU of virtual terminal also needs to increase transmission, and whether effective audio frequency is indicated activation command (AIA) to the expression audio signal of multipoint control unit transmission as terminal, is used to respond the instruction of this higher level's multipoint control unit.
The BAS sign indicating number that higher level MCU sends to " virtual terminal " MCU
The terminal that connects under the virtual terminal MCU wants to see all top site lists, and virtual terminal MCU must give one of own distribution M number.Adopt the mode of " use in the ini file self-defining M number " for M number, and require when M is set, to follow M number that is greater than all higher level MCU for following rule: M number,, make to be no more than 75 M number of own and subordinate in order to avoid conflict is less than some.
If system judges that at step S200 this virtual terminal does not send the BAS signaling to its higher level MCU, system also will judge whether that higher level MCU has sent the BAS signaling to this virtual terminal at step S300; If judge it is to have sent the H.230 video indication of order to activate (VIA) order in step S302 system, the processing of execution in step S302, this virtual terminal is set to higher level's port to the video source of all of the port except that higher level's port of this MCU.
If the higher level is looped back to virtual terminal to the video of serving from virtual terminal again, it send the VIN that gets off to represent MT number of virtual terminal so, this has just occurred " when terminal at the corresponding levels is watched higher level's port; see terminal at the corresponding levels; but the video indication is virtual MT number ", because terminal at the corresponding levels is an ignorant to virtual MT number, so will convert to MT number its actual MT number before VIN is transmitted to terminal at the corresponding levels.Therefore, system need increase determining step S306, promptly whether the BAS signaling that should be sent by the higher level is the VIN order of H.230 ordering, further, at step S308, if judging in the VIN order MT number is MT number of virtual terminal, the processing of this virtual terminal execution in step S310 is actual MT number of the terminal that converts the video source upper limit in the virtual terminal for virtual MT number to.
When higher level MCU issues TIL when order, if judging at step S316, this virtual terminal MCU receives this order, execution in step S318, the MT of virtual terminal number is removed, be transmitted to down the terminal that connects then.
When higher level MCU issues terminal indication distribution (TIA) order, if judging at step S320, this virtual terminal MCU receives this order, execution in step S322, filter this order and do not handle, still use MT number that is provided with in the ini file.
When the terminal of higher level MCU is done chairman, broadcasting higher level's terminal
Because " virtual terminal " MCU inserts higher level MCU as terminal, higher level MCU is obviously indication " broadcasting now " not, be broadcasted the meeting-place for guaranteeing that all terminals can both be watched, must remain on the terminal that connects under " virtual terminal " MCU under the state of watching higher level's video always.
When terminal added meeting first, just his video source was set to higher level MCU, but when behind the higher level MCU when virtual terminal starts, will be after higher level MCU adds meeting again the video source of terminal at the corresponding levels be set to higher level MCU.
When the terminal of higher level MCU is done chairman, the broadcasting virtual terminal
Because virtual terminal MCU inserts higher level MCU as terminal, higher level MCU does not send the VCB order to virtual terminal, just virtual terminal broadcasting back to its multiple spot indication visual (MIV) indication, which connects terminal under is to know and specifically will broadcast.This just requires the keeper of virtual terminal to cooperate, and sends out an order at the MCU operating desk, which meeting-place of designated broadcast.
Therefore, among the step S324, received the MIV instruction, made the video source of the port of virtual terminal MCU operating desk appointment is switched the port to the higher level, sent multiple spot virtual terminal (MVT) order of expansion BAS signaling to this designated port if this virtual terminal is judged.
When serving as chair cancellation broadcasting, be step S328, at this moment this virtual terminal can be received the CANCEL-MIV indication, wants execution in step S330, under connect each terminal and return under the state of watching higher level's video, report port to send the CANCEL-MVT order of expansion BAS signaling to former video source.
When virtual terminal fails to receive the BAS signaling that higher level MCU sends to this virtual terminal at step S300, if judge the AIA order of the H.230 order of receiving port at the corresponding levels at step S400, this virtual terminal thinks that its higher level's MCU port transmits this AIA order, i.e. step S402.
If received that at step S404 the MCU of subordinate in virtual terminal sends the TIA order, for guaranteeing in the level Four system, be no more than 75 M number, must revise virtual terminal from the MCU allocation strategy, therefore need execution in step S406, equal MCU at the corresponding levels number and add that port numbers adds one again for the MCU of subordinate number.
Virtual terminal following connects terminal when doing chairman, broadcasting higher level, the corresponding levels or subordinate's (if any) terminal
If broadcasting higher level terminal, (M, T) order is transmitted to higher level MCU to virtual terminal meeting the VCB that terminal sends up down.
If the broadcasting corresponding levels or subordinate's terminal, be sightless owing to connect MT number that terminal sends up down for higher level MCU, so must before transmitting the VCB order, change into them MT number of virtual terminal.After VCB is forwarded to higher level MCU, higher level MCU broadcasting virtual terminal, send out MIV to virtual terminal then, at this moment, note " operating desk designated broadcast port " and VCB port are united, otherwise virtual terminal can be broadcasted " operating desk designated port " because receiving MIV, cause the VCB command expiration.
The video camera far-end remote control
The terminal of virtual terminal MCU can be carried out the video camera far-end remote control to the terminal of higher level MCU, and the terminal of higher level MCU is carried out far-end remote control to the terminal of " virtual terminal " MCU by increasing new expansion BAS signaling.This because of: the far-end remote control data are to transmit by LSD, when the terminal of higher level MCU wishes that virtual terminal carried out far-end remote control, just transmit and comprise virtual terminal MT number remote-control data by LSD, " virtual terminal " MCU by increase self-defining BAS signaling MVT notice video be sent to higher level MCU terminal its have virtual terminal MT number, so when this terminal is received when comprising virtual terminal MT number video camera remote-control data, the video camera that draws oneself up according to remote-control data just.
Send this MCU name to main MCU
Because higher level MCU thinks that virtual terminal MCU is a terminal, so can send the meeting-place name of TCS2 order inquiry terminal.
When this virtual terminal MCU received the TCS2 order that higher level MCU sends, step S312, virtual terminal wanted execution in step S314 to send this MCU name, i.e. use information indication string (IIS) order is replied, and reports virtual terminal meeting-place name.