I. Overview
As the primary application of interactive video communication, video conferencing systems are gaining increasing popularity with the development of communication collection and encoding/decoding technologies. The current video conferencing system can be primarily divided into two architectures: PC based program systems and embedded hardware systems, both of which have vast product categories and their own characteristics. In terms of cost, program videos are aimed at the mid to low end market, while hardware videos are primarily targeted at the mid market; From an application perspective, program videos are primarily focused on desktop applications, while hardware videos are primarily focused on conference room applications. With the continuous development of the two architectures, there has been a certain overlap between the application markets of program video and hardware video, which poses multiple choices for users when establishing video conferencing systems.
Currently, most government agencies, military units, public institutions, and large enterprises are setting up video conferencing to improve office efficiency, enhance long-distance collaboration skills, and reduce travel and conference costs. How to select the most suitable video conferencing system based on the characteristics of the network itself is a problem that the vast communication collection department must consider. This article will briefly introduce the characteristics of program videos and hardware videos to assist network users in better choosing a suitable video conferencing system.
2、 Program video conferencing system and its features
Program video is a video communication format based on PC architecture, primarily relying on CPU to handle video and audio encoding and decoding work. Its biggest feature is low price, good openness, and easy program integration. However, the stability and reliability of program videos still need to be improved, and the video quality generally cannot surpass hardware video systems. Its current market is mainly focused on individuals and enterprises.
The program video conferencing system is a primary application of program video, primarily using a server+PC architecture. Deploy MCU servers, multi screen processing servers, and streaming media servers at intermediate points; Set up equipment layout USB cameras, earphones, and conference terminal programs on a popular desktop PC; Install high-performance PCs, video capture cards, conference cameras, and conference terminal programs in the conference room. When holding a video conference, use a Windows based operating interface to suspend various settings and governance of the conference.
Advantages of Program Video Conference System:
1. Deploying bento boxes
At present, the mainstream PCs equipped with equipment can be used as video terminals. These PCs are equipped with cameras, headsets and related programs, and can access the middle MCU server via the LAN or Internet to participate in the conference.
2. Integrated Data Conference
Because it is based on the Windows operating system, it can also perform data conference functions such as electronic whiteboards, template sharing, and file transfer during video conferences, serving as an auxiliary object for meetings.
3. Low cost
Because PCs used to be the standard equipment layout for office settings, desktop conference terminals do not require a lot of hardware investment. And the conference room type terminal only requires the purchase of a relatively high-performance PC and video capture card, and its cost is lower than that of ordinary hardware video terminals.
The weaknesses of program video conferencing systems:
1. Poor safety and stability
The program video is based on the Windows operating platform and PC architecture, and is relatively vulnerable to virus and hacker attacks, and is not suitable for long-term operation. Especially for program based conference room terminals, which use a large number of card insertion and peripheral supporting devices, the integration is low, there are many problems, and troubleshooting is also difficult.
2. Popular visual and audio effects
The USB camera used in desktop program terminals can only provide video quality lower than CIF, with low frame rates and poor color recovery. Although the conference room program terminal can be equipped with a layout of conference cameras, after measures such as video capture and program coding, the video delay is relatively large, and the video and audio flag lights cannot be synchronized.
3. The QoS guarantee mechanism is not sound
The QoS guarantee mechanism that most current program video processing plans cannot provide can result in video mosaic, delay, audio distortion, jitter, and other conditions when the collection and transmission conditions are poor.
4. The ability to support the collection of differences is relatively poor
Due to the general PC architecture, the program video processing plan can only support Ethernet line transmission and cannot support the dedicated line based H.260 collection architecture.
3、 Hardware video conferencing system and its features
Hardware video is a video communication architecture based on embedded architecture, relying on DSP+embedded programs to complete video and audio processing, communication collection, and various conference functions. Its biggest feature is high functionality and good reliability, and most of its applications adopt a hardware video format.
The hardware video conferencing system primarily includes embedded MCU, conference room terminals, desktop terminals, and other devices. The MCU is deployed in the middle of the collection process to handle and forward the bitstream; The conference room terminal is deployed in the conference room and interconnected with peripheral devices such as cameras, microphones, and televisions; The desktop terminal integrates a small camera and LCD display, which can be placed on the desk as a video communication object.
The advantages of hardware video conferencing systems
1. High integration
Hardware video terminals can provide multiple video and audio interfaces as well as collection communication interfaces. Some also have built-in video matrix functions, which can be used by simply connecting peripheral video and audio input/output devices and connecting them to the collection system. Hardware Multipoint Control Unit (MCU) can integrate multi screen partitioning, T.120 data services GK、 The integration of various hardware modules such as digital mixing is significantly better than the collaborative operation of multiple servers used in program systems.
2. Has * security and stability
Embedded architecture generation has * anti-virus capabilities, and more than 99% of viruses circulating cannot attack embedded systems. The design based on DSP processor enables hardware video conferencing equipment to have very low power consumption and stability. Some hardware video conferencing equipment also has functions such as backup of critical processing units, redundant heat dissipation, hardware AES encryption, firewall, etc., further ensuring the security and reliability of the system, and completing the collection of 7 × 24-hour non continuous operation.
3. Good video and audio effects
Due to the use of real-time operating systems and encoding/decoding technology, the video quality of hardware video conferencing products is generally higher than that of program products, and video and audio synchronization is also easily completed. Hardware video conferencing products can integrate video preprocessing, video optimization, and audio optimization technologies to further improve video and audio effects.
4. Flexible operation
Hardware video terminals commonly integrate remote control functions, and personnel who are unfamiliar with computers can suspend various settings and operations of video conferences through the remote control and OSD menu. Of course, hardware video conferencing systems can also be set up and operated via a PC for the purpose of controlling and managing large-scale conferences.
5. QoS guarantee mechanism with *
The hardware video conferencing system can support various QoS technologies such as RSVP and DiffServ, and through various underlying control and processing technologies, ensure the smooth operation of video conferencing in cases of poor collection quality.
6. Supporting universal communication collection
The hardware video conferencing system can also support the general specifications of H.23 and H.20, and can adapt to various collection and transmission prerequisites of dedicated lines or Ethernet.
The advantages of hardware video conferencing systems
1. The cost is slightly higher
The hardware video conferencing system adopts high-performance DSP processors and operating systems, which have significantly higher technical content than the program video conferencing system, and the product cost is also slightly higher.
2. Desktop extension requirements program support
Although there used to be pure hardware desktop terminals, they were relatively expensive and required a second information point in the office location. Many hardware video conferencing systems have been extended to the desktop through a programmatic layout, which not only facilitates the application of desktop layout, but also saves costs.
3. The investment risk is relatively high
Due to the adoption of the system, the hardware video conferencing system is a one-time investment and cannot be used for other applications like the servers used in the program system. So when users choose a hardware video conferencing system, they must consider the system's scalability and upgradability, such as support for future higher bandwidth collection and new features. In this regard, hardware devices designed with modularity are better than integrated hardware devices.
4、 Selection of Video Conference Network
Based on the advantages and disadvantages of program videos and hardware videos, network users need to separate their own characteristics to select the most suitable video conferencing system.
The demand characteristics of video conferencing network:
1. We need to hold a large-scale conference
Most video conferencing networks require large-scale conferences with over ten or dozens of venues, often involving hundreds of people. This requires that the conference cannot present infixes caused by equipment issues, and that the system has * stability. In addition, venues with dozens or hundreds of people also require video conferencing systems with high-quality video and audio capabilities.
2. High security request
Many internet users are in sensitive industries, especially in the military, *, *, courts, review courts, and so on. Their video conferencing needs security guarantees and cannot present leak work.
3. Joint venture transmission of video, voice, data, etc
Voice, data, and video are the three basic functions of communication networks. When establishing a video conferencing system, it is necessary to integrate voice and data collection to reduce the impact of different communication shutdowns and fully utilize the collected bandwidth capital.
4. Try to save money and establish costs as much as possible
The communication private network touches all levels of units in the entire system, and its architecture is quite significant. Therefore, controlling the collection and establishment costs is of utmost importance. We should try to choose a reasonable solution plan.
5. Minimize maintenance work as much as possible
Most internet users have relatively few professional personnel, especially at the end of the collection, there are basically no professional maintenance personnel. When establishing a video conferencing system, it is necessary to choose products with * stability and long-distance maintenance function.
Based on the characteristics of software and hardware video conferencing that video conferencing networks require, it is proposed to suspend the establishment of online video conferencing systems based on the strategy of "hardware system as the main component and program system as the auxiliary component".
Deploy highly integrated modular hardware video conferencing multipoint control units (MCUs) in the middle of the collection to ensure stable, reliable, and secure operation of the entire system. Highly integrated MCUs can integrate a wide range of functions such as multi screen processing, digital mixing, data conferencing, gateways, gatekeepers, stream adaptation, subtitles, etc., which can lower costs and improve stability more effectively than low integration MCUs combined with various supporting devices. Modular design can also give the system the ability to expand and upgrade.
Setting up equipment layout hardware conference room type video conference terminals in various conference rooms can achieve excellent video and audio effects, with much better stability and integration than program conference room type terminals. The equipment operation is cumbersome and the maintenance requirements are low. The current hardware conference room terminals mainly have two types: high resolution and standardized clarity, which can flexibly set equipment layout according to the size of the conference room and the needs of careful closure. If the system requires conference assistance function, a terminal with integrated dual stream function can be selected. When transmitting video streams, the debate machine screen or DVD image can also be used as the second video stream for transmission. Because many venues have multiple cameras installed, terminals with built-in video matrices can be chosen to save on the cost of external matrices. In addition, in order to adapt to the upgrades and changes in collection, consider products with communication interface expansion capabilities when selecting terminals.
Set up equipment deployment program video terminals in internal LAN or small branch offices, and connect them to hardware MCUs at intermediate points. This deployment can save equipment investment and enable flexible desktop video applications such as peer-to-peer instant messaging, small desktop meetings, VOD, etc.
Set up equipment layout single receiving hardware terminals or program terminals at some nodes that only require viewing conferences, which can retrieve images from other conference venues and also watch internally released video content. The hardware terminal has good stability and can be used immediately upon startup; The cost of the program terminal is slightly lower and can be selected based on practical requirements.
The selection of a program or hardware solution plan is a crucial step in the establishment of video conferencing collection. Once the establishment strategy is formulated, it is necessary to stop comprehensive consideration of various aspects such as communication mode pattern, collection bandwidth, video and audio encoding and decoding, system capacity, expansion capabilities, and system governance. This article elaborates on them in different ways.