Screen sharing in Flash video chat applications
We got a lot of questions regarding the possibility of screen sharing in flash so here you go, a simple public explanation:
Screen sharing is possible in Flash video chat applications by using third party screen sharing drivers. What these drivers do is they simulate a web cam that uses the desktop screen as a video feed.
There are 3 4 such drivers right now:
- VH Screen Capture Driver (http://www.hmelyoff.com/index.php?section=8) which is free for private use.
- the Live Output feature present in the Camtasia Recorder that ships with Camtasia Studio (http://www.techsmith.com/download/camtasiatrial.asp). Camtasia Studio is a comercial sofware and the actual bundle contains much more than just the Camtasia Recorder.
- May 2008 update: UScreenCapture (http://umediaserver.net/umediaserver/download.html), freeware for any use
- October 2011 update: XSplit (http://www.xsplit.com/) is a very good solution at this moment for screen sharing (currently in beta, you need to register to download and use, they have a few cool videos expaining how to use it)
There are several important differences between the 3 4 drivers above but that will probably make the subject of another future post.
For one to share his screen in a Flash video chat application he would have to install one of those drivers, then login into the chat software and change his video capture driver (right click->settings->video tab) to the newly installed screen sharing driver. This way when he will start his webcam the images/frames will come from the screen sharing driver.
Here are 3 tips for when doing screen sharing in a Flash video chat application:
- use 2 monitors: on one you put the application, window or element that you want to share, on the other you put the Flash video chat application which most probably will also display your screen video feed using the screen-share driver.
- increase the captured video resolution in your screen sharing video chat software to at least 320×240. When sharing areas of your screen smaller than 320×240 it will be very difficult for your viewers to keep track of the elements on your screen.
- There is a difference between the area (resolution) requested by your video chat software from the driver and the area (resolution) which is captured by the screen sharing drivers. The screen sharing driver might capture the entire screen, but the video chat software might request only a 640×480 area. In this case the driver might 1) stretch down the whole screen to fit 640×480 or 2) provide only the 640×480 area around the mouse (VH) or 3) provide only the 640×480 area around the center of the screen (Live Output and UScreenCapture).
It also worth mentioning here that Adobe has a special version of the Flash Player which does screen sharing out of the box. This special version is only available when used with their BRIO application/service available now in beta on labs.adobe.com. So if you want to do screen sharing, without using a third party driver, directly from a Flash Player application right now you are limited to using BRIO.
May 22, 2008 update: UScreenCapture added to the list.
October 23, 2011 update: XSplit added to the list.