Background technology
The video traffic in 3G (3rd-Generation, 3rd generation mobile communication technology) epoch has many kinds, video conferenceIt is one kind therein.Due to the original such as ability of network where access way, bearing mode, terminal type and terminal in video conferenceCause, causes the media transmission in primary video meeting in each node, all directions, media formats etc. to require far from each other.Moreover, during whole video conference, existing due to the feelings that the network condition that participant terminal occurs in a variety of causes changesCondition.
As shown in figure 1, to a 3G video conference, within certain a period of time, terminal A and VIG (Video direct-connected therewithInterworking Gateway, Video Interworking Gateway) between network condition it is excellent (with roomy and network stabilization), terminal ASound, video, Streaming Media coding/decoding capability is general and the terminal A expressive forces of itself are general, supports limited sound, video, stream matchmakerPhysique formula, such as maximum can only support CIF (Common Intermediate Format, a kind of standard image format, resolution ratioFor：352*288 pixels) video.
Network condition between terminal B and VIG direct-connected therewith is general (bandwidth is general and there is network congestion situation), butTerminal B sound, video, Streaming Media coding/decoding capability are powerful and expressive force of terminal B itself is excellent, support a variety of sounds, video, streamMedia formats, as maximum can support 16CIF (16-times Common Intermediate Format, a kind of standardized imagesForm, resolution ratio is：1408*1152 pixels) video.
Compared with the first two terminal, network condition between terminal C and VIG direct-connected therewith it is worst (network bandwidth it is small andFluctuation is big), and terminal C sound, video, Streaming Media coding/decoding capability be not strong and the terminal C expressive forces of itself are general, only supports non-Normal limited sound, video, stream media format are such as maximum only to support QCIF (Quarter Common IntermediateFormat, a kind of standard image format, resolution ratio is：176*144 pixels) video.
First assume the network between the direct-connected VIG of each terminal and MCU (Multi Control Unit, multipoint control unit)Situation is excellent.Because the initiator of video conference can be any terminal, first assume that terminal A is initiator here, terminal B andC add meeting, before meeting starts, each terminal need to by the sound of itself, video, Streaming Media coding/decoding capability collection and with it is respectiveNetwork condition between VIG reports MCU.Network condition and ability information that MCU is accessed according to terminal, are that each terminal is calculatedGo out acceptable complete media capability collection, and complete media capability collection is broadcast to terminal corresponding VIG, each VIG at thisGround preserves the complete media capability collection of each self terminal.For each terminal, each period of meeting (including when initialSection) there is a current media ability, each VIG is exactly to carry out audio frequency and video to direct-connected terminal by this current media ability to answerWith/the operation such as demultiplexing, code conversion, the media that the media information of terminal is reported into MCU and forwards MCU to come to terminalInformation.
During meeting progress, due to the influence of various external conditions, participant terminal (such as mobile terminal) and straight therewithNetwork condition between VIG even can change, and such as network condition is deteriorated, and will cause preventing network jitter using someSmoothing technique is unable to maintain that the original Video Frequency Conference Quality of terminal (the current media ability of terminal declines), or becomes in network conditionWhen good, in the range of terminal capabilities set support, Video Frequency Conference Quality lifting can be arrived higher level (the current matchmaker of terminalAbility of immigrants rises), and in current video conference, it is impossible to when network condition is deteriorated, maintain an acceptable mediaQuality, in network conditions turn good, it is impossible to lift existing media quality.
The content of the invention
The technical problem to be solved in the present invention is to provide a kind of conversion method of media capability in video conference, system and shouldWith server, media energy can be carried out application server triggering to participant terminal when the network condition of participant terminal changesThe conversion of power.
In order to solve the above technical problems, a kind of conversion method of media capability in video conference of the present invention, including：
Application server determines whether the network condition of participant terminal changes, the participant that network condition is changedThe current network conditions and media capability collection of terminal are notified to multipoint control unit.
Further, the application server determine the network condition of participant terminal whether change including：
The application server is opened in the number of times that the network condition that the participant terminal is reported changes more than timerIt is that the participant terminal starts network condition supervision timer during dynamic threshold value；
The application server is judged in the participant terminal in the timing of the network condition supervision timerWhether the number of times that the network condition of report changes is more than monitoring threshold, if it is greater, then determining the network of the participant terminalSituation changes.
Further, in addition to：
The multipoint control unit determines the network condition hair according to the current network conditions and media capability collectionComplete media capability collection of the participant terminal for changing under current network conditions, the complete media capability collection is notified to instituteState the corresponding Video Interworking Gateway of participant terminal that network condition changes；
The Video Interworking Gateway concentrates the current media ability that selection updates from the complete media capability, and with it is describedThe participant terminal that network condition changes carries out media capability switching.
Further, the Video Interworking Gateway carries out media capability with the participant terminal that the network condition changesSwitching includes：
The participant terminal is stopped to Video Interworking Gateway transmission up on up media channel, describedVideo Interworking Gateway is stopped on downstream media passage to participant terminal generation downlink media stream；
The participant terminal applies for up media channel and downstream media passage again to the Video Interworking Gateway；
Up media channel that the Video Interworking Gateway applies for the participant terminal again enters into media parameterMedia capability be set to the current media ability of the renewal, by going out to media parameter for the downstream media passage applied againIn media capability be set to the current media ability of the renewal, the up media channel and downstream media applied again are led toThe other specification in road is set to identical with former up media channel and downstream media passage, and discharges former up media channel and originalDownstream media passage.
Further, the participant terminal periodically reports the net between Video Interworking Gateway to the application serverNetwork situation.
Further, the complete media capability collection is notified to become to the network condition by the multipoint control unitAfter the corresponding Video Interworking Gateway of participant terminal of change, also pass through the corresponding video interconnection net of other participant terminals in video sessionClose, notify other described participant terminals changed with network condition described in meeting terminal to need to carry out media switching.
Further, a kind of application server, including：Network condition determining unit and information transmitting unit, wherein：
The network condition determining unit, for determining whether the network condition of participant terminal changes；
Described information transmitting element, for the current network conditions of participant terminal and media that network condition changesCapability set is notified to multipoint control unit.
Further, in addition to network information reception unit, wherein：
The network information reception unit, for receiving the network condition that participant terminal is reported；
The network condition determining unit includes：Timer Controlling subelement and network state change judgment sub-unit；
The Timer Controlling subelement, the number of times that the network condition for being reported in the participant terminal changes is bigIt is that the participant terminal starts network condition supervision timer when timer starts threshold value；
The network state changes judgment sub-unit, in the timing of the network condition supervision timer,Judge whether the number of times that the network condition that the participant terminal is reported changes is more than monitoring threshold, if it is greater, then determiningThe network condition of the participant terminal changes.
Further, a kind of converting system of media capability in video conference, including：Application server, wherein：
The application server, for determining whether the network condition of participant terminal changes, network condition is occurredThe current network conditions and media capability collection of the participant terminal of change are notified to multipoint control unit.
Further, in addition to：Multipoint control unit and Video Interworking Gateway, wherein：
The multipoint control unit, for according to the current network conditions and media capability collection, determining the networkComplete media capability collection of the participant terminal that situation changes under current network conditions, the complete media capability collection is led toKnow the corresponding Video Interworking Gateway of participant terminal changed to the network condition；
The Video Interworking Gateway, for concentrating the current media ability that selection updates from the complete media capability, andThe participant terminal changed with the network condition carries out media capability switching.
In summary, the present invention determines the network condition of participant terminal by application server in multipart video-meetingWhether terminal changes, so as to realize according to the current network condition of participant terminal and media capability collection adjustment current media energyPower, can ensure being smoothed out for video conference effectively and in real time, while farthest ensureing the experience of user.
Embodiment
VIG and MCU is under application server (AppServer) control in present embodiment, according to the matchmaker of each terminalNetwork condition between ability of immigrants and each terminal and VIG direct-connected therewith, determines the media energy used between VIG and terminalPower, carries out the transmitted in both directions of media.When the network condition between direct-connected VIG declines when terminal and therewith, by adjusting in timeMedia capability between VIG and terminal, it is ensured that business is normally carried out and Consumer's Experience；When terminal and therewith direct-connected VIG itBetween network condition when rising, by adjusting the media capability between VIG and terminal, improve the usage experience of user.
In present embodiment each participant terminal need dynamically every certain time length to application server report with eachNetwork condition between VIG, each one network condition of terminal profile of application server correspondence reports timer, in the timerTiming in, if it is determined that the network condition between participant terminal and VIG direct-connected therewith changes, by application controlNetwork condition between terminal and VIG is issued to MCU by server.
Each participant terminal is logically joined directly together with a VIG, and VIG is controlled by MCU, and MCU is by application serverControl.The Media Stream of VIG receiving terminals transmission is simultaneously forwarded to MCU, and forwarding flows to terminal from the MCU media come.Meanwhile,Necessary media conversion is according to requirements of service carried out in transmitting procedure, wherein, including sound, video media formats, code check and resolutionThe conversion of the one or more aspects such as rate size.
In video conference initial phase, each participant terminal needs to report each and VIG to MCU by application serverBetween network condition, and all sounds, video, the media capability of Streaming Media coding/decoding capability supported comprising terminal itselfCollection.MCU issues the network condition of each terminal and the complete media capability collection of the terminal obtained by calculating to corresponding VIG,VIG is locally being preserved.Each VIG concentrates selection current media ability from complete media capability, and current media ability is that participant is wholeHold the media capability that is being currently used between VIG, during video conference, any one period, each VIG with it is correspondingParticipant terminal have a current media ability, current media ability includes all of the Media Stream on uplink and downlink directionAttribute description.Media capability includes the media formats, code check and resolution dimensions that terminal is reported to VIG, and terminal is sent to from VIGMedia formats, code check and resolution dimensions etc..
Above-mentioned complete media capability collection refers to that MCU is according to the network condition between participant terminal and VIG, from participant terminalAll sounds for being supported, video, the media capability of Streaming Media coding/decoding capability are concentrated, calculate under current network conditions,The set for the media capability that participant terminal can be used.
During video conference, the network condition between participant terminal and direct-connected VIG may improve and may also becomeDifference, is illustrated by network conditions turn good and exemplified by being deteriorated separately below.
Assuming that during video conference, the network condition between terminal A and VIG1 direct-connected therewith is for some reasonIt is deteriorated, causes terminal A to decline to the VIG1 media qualities sent, it is discontinuous that flower screen, sound occurs in such as image.
As shown in Fig. 2 the conversion method of the media capability in video conference of present embodiment, including：
Step 201：Terminal A is periodically to application server report network situation；
Step 202：When the number of times that terminal A report networks are deteriorated is more than timer and starts threshold value, application server is eventuallyA is held to start a network condition supervision timer；
Step 203：Application server judges that the network condition that terminal A is reported is normally secondary in timer timingWhen number is less than monitoring threshold values, when timer timing is reached, application server sends switching control message to MCU, is disappearingCarried terminal A media capability collection and terminal A and the current network condition information of VIG direct-connected therewith in breath；
Step 204：MCU is calculated current according to terminal A media capability collection and current network condition information (variation)Complete media capability collection under network condition, and the complete media capability collection and relevant information are handed down to VIG1；
Step 205：VIG1 concentrates the current media ability that selection updates from the complete media capability under current network conditions,And carry out media capability switching with terminal A.
The step of VIG1 and terminal A carries out media capability switching in step 205 includes：
A) terminal A stops at up media channel and sends up to VIG1, but VIG1 does not discharge corresponding upMedia channel resource；
B) VIG1 stops at downstream media passage and sends downlink media stream to terminal A, but does not discharge corresponding downstream mediaChannel resource；
C) terminal A newly applies for required up media channel to VIG1, for up media channel, enters and is removed to media parameterThe outer other parameters of media capability keep constant, and the media capability entered to media parameter is set into the current media energy after updatingPower, goes out constant to media parameter and former passage holding；
D) terminal A newly applies for required downstream media passage to VIG1, for downstream media ALT-CH alternate channel, enters and joins to mediaNumber keeps constant with former passage, goes out to media parameter that other parameters holding is constant in addition to media capability, will go out to media parameterMedia capability is set to the current media ability after updating；
The Media Stream that the downstream media passage newly applied directly continues from the MCU terminal B come and terminal C；To terminal B andTerminal C Media Stream is changed by the media capability after renewal, and the Media Stream after conversion is output to terminal A by original parameter.
E) resource of the former uplink and downlink media channel of VIG1 releases；
F) VIG1 and terminal A starts the transmission and conversion of Media Stream in new uplink and downlink media channel.
MCU also notifies terminal B and terminal C, terminal after complete media capability collection is issued to VIG1 by VIG2 and VIG3A is needed to carry out media switching because network condition is deteriorated, and user is pointed out by terminal B and C.
Whole handoff procedure is completed, and the media capability after renewal turns into the current media ability between terminal A and VIG1.CutTerminal A two-way media stream can be interrupted temporarily during changing, on terminal B and terminal C counterpart terminal A Media Stream also can temporarily inDisconnected, counterpart terminal C Media Stream is unaffected on terminal B, and counterpart terminal B Media Stream is also unaffected on terminal C.To allFor impacted terminal, whole handoff procedure control is within one second.
As shown in figure 3, during video conference, the network condition between terminal C and VIG3 direct-connected therewith is due to certainPlant reason to improve, in the range of terminal C media capability collection, media quality has the space risen between VIG3 and terminal C.
With reference to Fig. 3, the conversion method of the media capability in video conference of present embodiment, including：
Step 301：Terminal C is periodically to application server report network situation；
Step 302：Application server receives the network condition message that terminal C timings are reported, and is receiving the net that terminal C is reportedIt is that terminal C starts a network condition supervision timer when number of times that network situation improves is more than timer startup threshold value；
Step 303：Application server is in the range of the timing length of timer, if receive that terminal C reports is network-likeThe number of times that condition improves is higher than monitoring threshold, when timer timing reaches, issues switching control message to MCU, in messageCarried terminal C media capability set current network conditions information；
Step 304：MCU is calculated under current network condition according to terminal C media capability collection and current network conditionsComplete media capability collection, and the complete media capability collection and relevant information are handed down to VIG3；
Step 305：VIG3 concentrates the current media ability that selection updates from the complete media capability under current network conditions,And carry out media capability switching with terminal C.
The step of VIG3 and terminal C carries out media capability switching in step 305 includes：
A) terminal C stops at up media channel and sends up to VIG3, but VIG3 does not discharge corresponding upMedia channel resource；
B) VIG3 stops at downstream media passage and sends downlink media stream to terminal C, but does not discharge corresponding downstream mediaChannel resource；
C) terminal C newly applies for required up media channel to VIG3, for up media channel, enters and is removed to media parameterThe outer other parameters of media capability keep constant, and the media capability entered to media parameter is set into the current media energy after updatingPower, goes out constant to media parameter and former passage holding；
D) terminal C newly applies for required downstream media passage to VIG3, for downstream media ALT-CH alternate channel, enters and joins to mediaNumber keeps constant with former passage, goes out to media parameter that other parameters holding is constant in addition to media capability, will go out to media parameterMedia capability is set to the current media ability after updating；
New downstream media passage directly continues the former Media Stream from the MCU terminal A come and terminal B；To terminal A and endEnd B Media Stream is changed by the current media ability of renewal, and the Media Stream after conversion is by original parameter output media to nextJump or distal end.
E) resource of the former uplink and downlink media channel of VIG3 releases；
F) VIG3 and terminal C starts the transmission and conversion of Media Stream in new uplink and downlink media channel.
MCU also notifies terminal A and terminal B, terminal after complete media capability collection is issued to VIG3 by VIG1 and VIG2C needs to carry out media switching due to network conditions turn good.
Terminal C two-way media stream can be interrupted temporarily in handoff procedure, and on terminal A and terminal B counterpart terminal C matchmakerBody stream also can be interrupted temporarily, and counterpart terminal B Media Stream is unaffected on terminal A, counterpart terminal A Media Stream on terminal BUnaffected, for all impacted terminals, whole handoff procedure control is within one second.
Fig. 1 is refer to, the system of present embodiment is included：Application server, Video Interworking Gateway and multipoint control unit,Wherein：
Application server, for determining whether the network condition of participant terminal changes, network condition is changedParticipant terminal current network conditions and media capability collection notify to multipoint control unit.
As shown in figure 4, application server includes：Network information reception unit, network condition determining unit and information are sentUnit：
Network information reception unit, for receiving the network condition that participant terminal is reported；
Network condition determining unit, for determining whether the network condition of participant terminal changes；
Information transmitting unit, for the current network conditions of participant terminal and media capability that network condition changesCollection is notified to multipoint control unit.
Network condition determining unit includes：Timer Controlling subelement and network state change judgment sub-unit；TimerSubelement is controlled, when the number of times that the network condition for being reported in participant terminal changes is more than timer startup threshold value, isParticipant terminal starts network condition supervision timer；
Network state changes judgment sub-unit, in the timing of network condition supervision timer, judging participantWhether the number of times that the network condition that terminal is reported changes is more than monitoring threshold, if it is greater, then determining the net of participant terminalNetwork situation changes.
Multipoint control unit, for according to current network conditions and media capability collection, determining that network condition changesComplete media capability collection of the participant terminal under current network conditions, complete media capability collection is notified occur to network conditionThe corresponding Video Interworking Gateway of participant terminal of change；Also pass through the corresponding video interconnection net of other participant terminals in video sessionClose, notify other participant terminals changed with meeting terminal network situation to need to carry out media switching.
Video Interworking Gateway, for from complete media capability concentrate selection update current media ability, and with it is network-likeThe participant terminal that condition changes carries out media capability switching.
The participant terminal that Video Interworking Gateway changes with network condition, which carries out media capability switching, to be included：
Participant terminal is stopped on up media channel to Video Interworking Gateway transmission up, Video Interworking GatewayStop on downstream media passage to participant terminal generation downlink media stream；
Participant terminal applies for up media channel and downstream media passage to Video Interworking Gateway again；
The media energy entered into media parameter for the up media channel that Video Interworking Gateway applies for participant terminal againPower is set to the current media ability updated, by the media capability gone out into media parameter for the downstream media passage applied againThe current media ability updated is set to, the other specification of the up media channel applied again and downstream media passage is setTo be identical with former downstream media passage and downstream media passage, and discharge former up media channel and former downstream media passage.
Obviously, those skilled in the art should be understood that above-mentioned each module of the invention, each step can be with generalComputing device realizes that they can be concentrated on single computing device, or be distributed in what multiple computing devices were constitutedOn network, alternatively, they can be realized with the executable program code of computing device, it is thus possible to be stored inPerformed in storage device by computing device, either they are fabricated to respectively each integrated circuit modules or by theyMultiple modules or step are fabricated to single integrated circuit module to realize.So, the present invention is not restricted to any specific hardPart and software are combined.
Embodiments of the invention are the foregoing is only, are not intended to limit the invention, for those skilled in the artFor member, the present invention can have various modifications and variations.Any modification within the spirit and principles of the invention, being made,Equivalent substitution, improvement etc., should be included in the scope of the protection.