| You should Know
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A. Server Installation |
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| 1 |
After installing AVCON server and updating its authority, I still am noticed authority outdated. |
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You'd better set a right server time. In trial version system will inform you authority outdated when it find the server time is quite different from the actual time. |
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| 2 |
The avconserver cannot be started by restarting server, but it works well when I start it by hand. |
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Exam the file of /etc/rc.local, maybe you have checked other functions. And it starts other functions before you finished avconserver setup.
You can add words "sleep 5" under starting command of avconserver to give system 5 seconds after finishing setup avconserver.
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| 3 |
What types of networking does AVCON system support? |
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Telephone line, ISDN, ADSL, cable television network, twisted pair to broadband network and any other access service line which can provide true Internet IP |
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B. Background management |
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It has many ways for AVCON Web Video Conferencing System to access to Internet. |
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Dial-up, ISDN, ADSL, Cable TV Network, Twisted Pair Broadband and any other kinds of lines accessing to Internet actual IP
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I cannot visit webpage. |
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1) httpd has stopped. Please check httpd process in Linux system.
2) Port 80 is closed. You can check it by port test program.
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Where to update my software? |
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We will update your conferencing server once we have a latest version. You can finish software update by following our reminder. |
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The ports used by video conferencing system: |
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1) Ports for AVCON4.0
TC:P80,8282,8287
UDP:8282-8286
2) Normal connection of AVCON4.2
TCP:80,8880,8881
UDP:8880-8885
3) proxy
TCP:80,443 |
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Database connection error when I visit webpage. |
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The service of mysqld has stopped, you can check it system. |
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Before holding conference, system administrator should do: |
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Add user, set password; allocate uplink and downlink for stream media server; open conference room and set its name, property, time; configurate user authority and send meeting notice to attendees.
Usually you can build departments and staffs according to company infrastructure, and now you just choose some of them to add the meeting.
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It cannot detect right version information after WINDOWS version installation. Neither update hint when user end log in. |
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Please check avFilePath in the file of avPlatform\htdocs\avconf.ini. If its information is wrong, system will fail to update for no right version information. |
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| 8 |
I can not open the page of bandwidth test after log in. |
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Make sure you have connected to server. Then please check whether http is working, whether configuration file is right, or whether TCP port 8880 is open. |
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| 9 |
Please take 720-way as an example to explain capacity calculation. |
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1) 720-way is the sum of "the number of video input" and "the number of video output"
2) For example, in 15-point and 10-way video meeting: 10-point among 15-piont will send 9-way video and receive 1-way video, which is allocated 100-way uplink (90-way out, 10-way in); other 5- point among 15-piont just view other 10-point, that is these 5-point send 10-way and receive 0-way, which is allocated 50-way. In a word, 140 video total 140 video sending out, 10 video receiving, that is allocated 150-way video.
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| 10 |
When testing bandwidth, if there are two networks connect to one server, it would be one of them works well. The users in other network cannot open the test page. |
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Because you only can fill in one of IP addresses in WeBSeRVeR of the file of avconf.ini. And only one of their users can log in test page if the two networks cannot visit each other.
You can blank one of IP address, which will be invoked by system to resolve this problem.
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C. Video & Audio |
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Discontinuity in images and sound |
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The biggest advantage of AVCON Web Video Conferencing System is its constant perfect images and sound. But in the case of 100% CPU occupied or inadequate bandwidth, it will be shattered. And you'd better reduce the number of receiving video to cut down the consumption of CPU and bandwidth. |
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Notices when installing capture card |
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When installing the BT878 capture card, the following precautions should be taken into account.
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1) Here you should do some modifications like following: |
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Then click "Next": |
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2) At last you will see two devices of "Conexant's BtPCI WDM Video Capture" and "Conexant's BtPCI WDM Audio Capture". Continue you will finish the whole installation. |
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| 3 |
Audio device setting |
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Double click "volume" icon in WINDOWS bottom (if you cannot find out the icon, please come to " start set control panel voice and Multimedia" to click "display volume control in task bar", like below: |
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A. Click Menu" Options Properties", pop below window: |
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Check "Play" in the box of "volume adjustment" (Notice: Make sure to check right device in the box of" mixer device"). Check "Line in" and "Microphone" in the box of "Show the following volume control". Click the button of "OK" and be back to "Master Volume" window where check "Mute" for "Line in" and "Microphone" to avoid echo. As below: |
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B. Click Menu "Options Properties', pop below window: |
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Check "Recording" in the box of "Adjust volume for" (Notice: Make sure to check right device in the box of" mixer device". Logitech will appear here if it is not prohibited.) Be sure to check "Microphone" in the list of "Show the following volume control", or it maybe no voice (Sometimes, it is "Line in"). Click "OK" button and back to "Master Volume", like following: |
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Check "Select" in "Microphone" box, and then click "Advanced", and "Microphone advanced control" window pops up. To avoid the other party hear noise, you can cancel "Other Controls", and then click "Close". As follow: |
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| 4 |
No video after the client's normal logon. |
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1) Check whether the video capture device is driven normally.
2) Check whether power of video camera is switched on.
3) Check whether the video camera is in standby mode.
4) Make sure the video capture device is properly connected.
5) Make sure the video capture device in [Video Tuning Wizard] of client is selected.
6) Make sure the video standard is the local general standard, for China area, the video standard is PAL_D or PAL_B.
7) Make sure the [Input] in Video Preview window in [Video Tuning Wizard] of client is set as connecting port for the physical connection of current capture card.
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| 5 |
No audio after the client's normal logon. |
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1) Check whether the audio capture device is drove normally.
2) Check whether audio capture device, audio output and control device are in working mode.
3) Check whether the audio capture device is properly connected.
4) Make sure the [Microphone] in [Audio Tuning Wizard] of client is set as the current applicable audio capture device.
5) Make sure the selected port of microphone in [Audio Tuning Wizard] of client is identical with the physical port of microphone (audio capture device).
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I do not know the reason that only 2-way video is normal and others are black screen. |
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It is because no stand-alone video card in the computer. Besides stand-alone video card, AVCON Web Video Conferencing System also demands video RAM is more than 32M. |
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Sometimes 2 videos flash in one |
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It is mainly due to INTEL integrated video card. The problem can be resolved by updating driver. |
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Sometimes I cannot receive video from somebody, but it is normal form others. |
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Usually for one route you are in. The system will consider you are in one LAN and send video and audio by internal network. It is impossible to communicate each other when they are in different network segment or one of them set limitation in firewall for LAN users.
You can check "USeONLY" in "User" of "Options" to ensure interactive communication under any case.
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| 9 |
Local video effect is down automatically. |
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The newest version can adjust local video automatically. If the network condition is not so good the system will reduce local video effect to keep audio work normally.
Besides, if you check "video auto-adjust by CPU" in "video-telephone" of "Options", the video effect will be down under high percent user CPU.
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| 10 |
Discontinuity and bad audio effect in software after installed with hardware echo canceller. |
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Maybe you have checked "AGC' and "AEC" the two boxes in "Options". Please cancel them. |
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D. conference |
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Several problems and their resolution in the conference. |
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1) Noise. Please inhibit the microphone of webcam like: Logitech 4000. Or adjust it in video & audio adjust wizard.
2) Squeaking. Mute microphone in volume master; close microphone strength.
3) Voiceless. Make sure right hardware connection, check microphone in recording control.
4) Video display nonfluency. Adjust the video to normal standard. It cannot be too high.
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Is it possible to enter conference without any adjustment for the first time? If we need, please list out adjustment steps. |
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Of course you can use our software first time without any adjustment as long as your microphone and webcam works well and their resolution and frame rate in default mode. |
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Is it necessary to adjust system each time and to maintain the conference whole-process by technicians? |
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No. It is not necessary to adjust each time. The system can remember the latest change and parameters.
Not necessary. Administrator can control, adjust and maintain in main boardroom. A little technique for people in branch rooms to master.
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What should administrator do after the conference? |
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Nothing for administrator do after the conference for the database will be refreshed automatically after all attendees exited. Then the recording will be stopped. You can direct play it. |
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Whether the conference system will detect and use installed video and audio devices or not? Only simply operation is OK for users? |
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Yes only simply operation for users. And Conference Administrator can check and modify each attendee's PC system configuration in distant place. |
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Users' manual to emergences (such as internet slowness, bad effect of audio & video and etc) in conference. |
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If you find the bandwidth is too narrow to get fluent video or audio. You can cancel some video and audio, or mute some video meanwhile choose different TCP or UDP to ensure smooth audio, or adjust your and other attendees' data stream to save bandwidth.
Of course, please not worry more about it. AVCON' system has the ability to keep intact picture under slow network.
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NO conference after clicking "Conference". |
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1) Be sure you have conference to attend.
2) Whether the conference is stopped by administrator.
3) Restart the database and mysqld service then to check it.
4) Enter Background Management to build a new conference by Administrator Account, and then check it,
5) If it works before, maybe dues to grantee expired. You'd better contact Shanghai Huaping as soon as possible.
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No video after entering the conference. |
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1) Make sure you enter the conference as host or attendee or observer.
2) If you are host, please click "receive others video".
3) If you are attendee or observer, please be sure the host broadcast its video and audio.
4) Make sure you and he have been allocated.
5) Maybe he login by proxy and configurate it to server port as login method.
6) Maybe his firewall and port are close.
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I found I am not in the same pace with other partners. |
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1) Make sure you and they are in the same conference.
2) Be sure you have checked "synchronize setting" in "conference" in "Options".
3) If your conference has many hosts, and other hosts received more video than you, please close the broadcasted video.
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I have added new contacts, but I cannot see their names. |
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Please make sure you have clicked "OK" in "User" in "Options" when you add them, and meanwhile get confirmation from them. |
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I cannot view previous P to P instant messages with others. |
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1) Maybe you did not check the box of "Save chat history automatically" of "Options".
2) Maybe you have re-setup your software.
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I cannot P to P video call, whiteboard, screen share or send files with others. |
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1) Make sure he is online.
2) Make sure he has webcam
3) Make sure your server port is open
4) Maybe someone login across http Tunnel, and server do not support it
5) Whether some hints appear like: his video useless. Now you need to configurate some resource to him.
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One of video in screens is black in double screen display. |
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It is due to operating system.
You can open one video file in MediaPlay or Realplay before enter conference. Pause it after several seconds. It will be OK.
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| Terms and Expression
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A. AEC AGC ANS |
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AEC |
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It is due to operating system.
You can open one video file in MediaPlay or Realplay before enter conference. Pause it after several seconds. It will be OK
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AGC |
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is Automatic Gain Control. It can adjust sound to a proper volume regardless of distant change.
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ANS |
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is Automatic Noise Suppression. It can detect out regular or irregular noise like fan noise or air conditioner noise or others and return listeners clear voice.
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B. RTP / RTCP |
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RTP |
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means Realtime Transport Protocol which is used for multimedia data stream in Internet issued as RFC1889 by Internet Project Group. RTP is defined as one-to-one or one-to-many transport protocol to realize time information synchronization. Usually RTP is based on UDP, TCP or ATM sometimes. The shortcoming of RTP is only for real-time transportation. It has to rely on RTCP to supply reliable delivery mechanism in sequence and flow or congestion control.
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RTCP |
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is Realtime Transport Control Protocol which is responsible for transport quality and exchanging control information among current tasks. During their dialogue, attendees' data will be sent to PTCP regularly. Server will adopt these dynamic data which contains the number of already packets, lost packet and other useful data to change transport rate and effective load type. Internet companies often use RTP and RTCP together to optimize transport rate in lowest cost.
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C. MPEG1 MPEG2 MPEG4 |
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A comparison table among MPEG-1, MPEG-2 and MPEG-4 |
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Image |
Frame Rate |
Bandwidth |
Field |
| MPEG-1 |
352x24 or 320x240 |
24-30 fps |
1.5 Mbps |
Video CD, CD-ROM |
| MPEG-2 |
720x24 or 640x480 |
24-30 fps |
4-8 Mbps |
DTV, HDTV, DVD-Video |
| MPEG-4 |
34x48 ~ 4096x4096 |
1-30+fps |
10Kbps~10Mbps |
Internet, wireless transport, interactive TV |
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The table tells you a fact that MPEG-1 and MPEG-2 mainly used in stable media, like VCD and DVD. And MPEG-4 has an overwhelming advantage in network transmission.
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. Audio Encoder |
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Parameters from ITU of G voice compression criteria |
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Algorithm |
Type |
Code Rate |
Delay in Algorithm |
| G.711 |
A-Law /-Law |
64 |
0 |
| G.722 |
SB-ADPCM |
64/56/48 |
0 |
| G.723.1 |
MP-MLQ/ACELP |
6.3/5.3 |
37.5 |
| G.726 |
ADPCM |
16/24/32/40 |
0 |
| G.727 |
Embedded ADPCM |
16/24/32/40 |
0 |
| G.728 |
LD-CELP |
16 |
<2 |
| G.729 |
CS-ACELP |
8 |
15 |
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We will update your server at the first time when we have the newest version. Users will update it automatically in your own computers.
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E. Light Luminous flux Lumen output Pharosage Luminosity |
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Light |
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plays an important role in our visual ability, which is the result of complex interaction of light, eyes and brain. It is a transverse wave from 380-millimicron to 780-millimicron, give human different sense of color. Our eyes will not catch wave beyond that range. We call the wave longer than 780-millimicron infrared radiation and shorter than 380-millimicron ultraviolet radiation.
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Luminous flux |
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is a weighted sum of the power at all wave length in the visible band. Its symbol is and unit is LM. Human eyes have different sensitivity to light for their wave length, and the most sensitive is yellow and green light of 555-millimicron long in day or the place with strong light. And the longer wave, the weaker sensitivity. In other words, luminous flux is related with radiation intensity and wavelength. We consider the relative sensitivity of wavelength as V{).
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Luminous intensity |
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is the perceived power per unit solid angle. Its unit is cd.
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Luminous exitance |
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is luminous flux per unit area. Its symbol is E and unit is LUX. Luminous exitance in full moon night is 0.21 LUX and in noon bright sunshine is (
0.2-1) *105 LUX.
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Light out |
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means luminous intensity luminosity body project in one direction per unit area. Its symbol is L, and unit is nt. |
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F. VoIP |
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At present, VoIP protocol is divided into two parts: SIP protocol and H.323 protocol.
SIP is short for Session Initiation Protocol. They are criteria proposed by communication area and internet area. H.323 tries to consider IP telephone as traditional telephone by changing transport pattern and replace circuit switching with packet switching. SIP takes IP telephone as one application of Internet, which adds signals and QoS for FTP and E-mail. It seems that they are the same in regarding RTP as multimedia transmission protocol besides H.323 more complex than SIP.
At the beginning, H.323 protocol is a suggestion for packet switching network of multimedia conference proposed by ITU-T in 1996. As an protocol framework, H.323 provides description for system and its components, voice and video encoding, call method and call signals and no QoS, etc.
H.323 brings interoperability into collaboration among devices, management teams and suppliers. It is independent of network architecture, operation system and hardware platform to enable multi-point function, multi-cast and bandwidth management. The information stream of multimedia conferencing system in H.323 which was packed and sent according to H.225.0 protocol contains audio, video, data, and control message.
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G. NTSC, PAL, SECAM |
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Baseband video is a type of simple analog signals, composed of analog video data and synchronous video data to display video used by receiving end. Signals quality would depend on video standards or systemNTSC, USA National Television Standards Committee; PAL, Phase Alternating Line; and SECAM, Sequential Couleur Avec Memoire.
Most North American Countries and Japan would use NTSC, and French adopts SECAM, China is willing to adapt PAL-D system. These systems are hard to be unified.
Incompatibility exists in PC area for various systems. Take resolution as example, PAL, SECAM maybe use 625 lines at 50Hz but NTSC would use 525 lines at 60Hz.
Generally, one video source produces one video signal like camera, VCR or TV adaptor, which also generates a V SYNC to deliver images that would reset PC monitor to enable a complete image displayed. That is to say, video source will come to next step to scan the first line of image after sending VSYNC, then generate a HSYNC and reset PC monitor to make sure next line displayed from screen left side, and then send one scanning line and HSYNC signal for each image line.
Moreover, NTSC standards demands 30 complete images per second. There will be serious flash to reduce if no treatment. In order to resolve the problem, NTSC cuts frame into two parts: odd line and even line. Monitor scans odd lines first then even lines. Maybe it is a good idea to avoid flashes.
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