Screen sharing
Screen sharing , screen sharing or desktop sharing refers to the transfer of the screen contents of a computer to one or more other computers. For users at remote computers, this creates the impression of being right in front of the remote computer.
Corresponding software can be found in both business and private areas, but its functionalities can differ greatly, which is why categorization or clear delimitation is often difficult.
Applications
Coordination of work
When working across distributed locations, several participants can work together on documents or present finished content using desktop sharing. In this area, however, technology is confronted with more efficient alternatives. For example, the Google Drive service enables decentralized work on joint projects as well as communication, preferably via conference calls and instant messaging .
Remote access
Remote access is possible if the corresponding software has extended functionalities . In this case, the remote computer or server is controlled remotely without having to be on site. This concept is used in very small as well as in large companies and industry.
Support
Assistance for customers is the largest area of application of the desktop sharing concept. In the private sector, however, this variant is usually used very late, i. H. only when the usual and simpler offers ( FAQ , Internet forums , chats or screencasts ) have been exhausted. It should be noted that help via a desktop sharing program is only possible if both participants have installed the program, which rules out useful assistance in the event of hardware or network problems.
Live events and gaming
Another application is live broadcasts of computer games , application software and Internet content, for example in the context of a video press conference, a web seminar or a live demonstration or presentation. If the screen transmission is aimed at a larger audience, the content can be broadcast on livestream services such as Twitch YouTube Live . Many players enjoy watching other players play. A screen transfer is therefore also suitable as a live Let's Play .
software
| program | License, costs | protocol |
Port forwarding required |
Remote control | Chat | video conference | File transfer |
|---|---|---|---|---|---|---|---|
| Adobe Acrobat Connect Pro | proprietary, chargeable | own proprietary protocol | ? | X | X | X | X |
| Discord | proprietary, free | X | X | X | |||
| FFServer | free software | RTP / RTSP | ? | X | |||
| LogMeIn Hamachi | proprietary, chargeable | own proprietary protocol | No | X | X | ||
| Lotus Sametime | proprietary, chargeable | own proprietary protocol | ? | X | X | X | X |
| Mikogo | proprietary, free for private users | own proprietary protocol | No | X | X | X | X |
| TeamViewer | proprietary, free for private users | own proprietary protocol | No | X | X | X | X |
| TurboMeeting | proprietary, chargeable | own proprietary protocol | No | X | X | X | X |
| Tox | free software | own open protocol | No | X | X | X | |
| Mozilla Firefox | free software | WebRTC | No | X | X | ||
| Google Chrome Remote Desktop | free software | WebRTC | No | X | X | X | |
| Polycom RealPresence Desktop | Single license, chargeable | H.323 / SIP standard protocol | No | X | X | ||
| Skype | proprietary, basic scope free of charge | own proprietary protocol | No | X | X | X | |
| UltraVNC | free software | VNC | Yes | X | |||
| Vino and Vinagre | free software | VNC | Yes | X | |||
| Yealink VC Desktop | Single license, chargeable | H.323 / SIP standard protocol | No | X | |||
| Apple Remote Desktop | proprietary | VNC | ? | X | |||
| Jitsi | free software | open protocol based on XMPP | Yes | ? | X | X | X |
| AnyDesk | proprietary, free for private users | proprietary protocol (deskRT) | No | X | X | X | |
| Open Broadcaster Software | Free software , free | X | X | X | |||
| Steam | proprietary, free | X | X | X |
Specializations
Over time, methods for special areas of application have developed, supported by adapted software.
Website monitoring
Under Web site monitoring refers to the live monitoring of websites such. B. offered by live support systems for active support for the site visitors. As part of the monitoring, customer service representatives can determine the activities of visitors on the site, start a conversation ( chat ) and, if necessary, help with filling out forms.
Since the customer advisor sees the same thing as the customer, website monitoring offers a wide range of options for supporting site visitors. In contrast to remote access, however, only the page content and activities of the visitor on the page can be determined.
Cobrowsing
Cobrowsing or co-surfing is the joint navigation through the World Wide Web on two or more computers, e.g. B. by synchronizing the browser . Surfing together supports the transfer of information and makes it easier to find the desired pages, for example in customer service or sales
Further examples of cobrowsing are, for example, schoolchildren who work on learning content with an online tutor, business partners who look at web presentations together , or even chatters who exchange information about their stay on the Internet by sending URLs .
Application sharing
The terms application partitioning , application distribution or English application sharing designate a supplement to the audiovisual conference .
Programs, data or objects are used by two or more participants at the same time by enabling mutual access to a PC or joint work on one computer. Application sharing can take place passively (presentation, viewing of objects) or actively if several participants can actually work actively on an application ( tele- cooperation ).
Typically, one computer system provides the application (this system is called the host ) while it is accessed by one or more other computer systems ( clients ). A typical example is the joint editing of a document between two people who are in different locations.
Compression of screen contents
The transmission of content displayed on computer screens (English: screen content) requires special compression techniques. Conventional video compression methods specialize in image data that have been recorded with photo or video cameras. However, screen contents are predominantly characterized by regions with graphic elements (window structures, icons, etc.) and text. With lossy compression at normal bit rates, the visual quality of these regions is generally very poor. Ideally, text and graphics should be compressed without loss or with almost no loss. The latest standard for video compression, HEVC, contains special tools to compress the content on a block-based segmentation either with conventional methods or with methods that are suitable for text and graphics. In the meantime, however, there are already approaches that enable significantly higher compression rates with lossless compression.
Web links
- How Desktop Sharing Works - background information on how it works at howstuffworks.com
Individual evidence
- ↑ Screen sharing and video calls. Retrieved February 21, 2018 .
- ↑ ffserver Documentation
- ↑ Control remote computers and share your screen with friends. TeamViewer is free for private users. Retrieved February 21, 2018 .
- ↑ Desktop and screen sharing in real time with chat, VoIP, telephone and webcam. Retrieved July 20, 2018 .
- ↑ How do I share my screen in Skype? | Skype support. Retrieved February 21, 2018 .
- ↑ Open Broadcaster Software | Home page. Retrieved February 21, 2018 .
- ↑ Steam Community :: Steam Broadcasting. Retrieved February 21, 2018 .
- ↑ ITU-T H.265 / ISO / IEC 23008-2 HEVC: High efficiency video coding , recommendation, April 2013
- ↑ Xu, J .; Joshi, R .; Cohen, RR: Overview of the Emerging HEVC Screen Content Coding Extension. IEEE Trans. On Circuit and Systems in Video Technology , Vol.26, No.1, Jan. 2016, 50-92
- ^ Strutz, T .: Lossless Intra Compression of Screen Content based on Soft Context Formation. IEEE Journal on Emerging and Selected Topics in Circuits and Systems - Screen Content Video Coding and Applications , Vol.6, No.4, 2016, 508-516