Joined: 27 May 2007
Location: Brighton, CO
|Posted: Thu Dec 06, 2007 1:44 am Post subject: Looking for suggestions for an upgrade to a V.C. solution
|A couple of years ago, I used version 4.0 to create a video conferencing solution between 5 fire stations for training. My concept for doing this was that I only needed 1-way video but 2-way audio because I was broadcasting from our training room and I wanted the firefighters in the outlying stations to be able to ask questions. Furthermore, I wanted an easy way to integrate live video with the windows desktop so that the instructors could either use a video camera hooked up to a capture card or the Windows desktop with PowerPoint (or whatever else they would like to display in the classroom).
Unreal Media Server performed beyond my expectations. I used the Screen Capture Add-On to broadcast the Windows desktop for PowerPoint (etc.) and I was able to write some simple macros that were launched by Function keys that brought up and hid the live video from the capture card onto the Windows desktop. This gave the instructors a quick, easy way to switch back & forth between PowerPoint and the video camera. I even added more macros (launched by Function keys) to change the size of the window from the capture card which allowed for a picture-in-picture with a PowerPoint slideshow running with the video from the capture card running in the corner. I even added more macros to start and stop the recording feature so my instructors could record their training sessions on the hard drive.
After figuring all of that out, I thought the 2-way audio was going to be the simple part but it turned out to be another challenge. My first idea was to use a simple audio conferencing application installed on the same computer instead of using the audio from Live Server. But this created synchronization problems. The video from Live Server had low latency but it wasn't zero latency and it usually ran anywhere from 1/4 to 1 second behind the audio. What I had to do was use the outgoing audio from Live Server and use the incoming audio from my audio conferencing software with a Push-to-talk feature. The push-to-talk feature also muted the speakers on the remote computers to eliminate feedback (which came across as an echo because of the latency).
It took quite a while but it was satisfying to overcome all of the obstacles to save tens of thousands of dollars that might have been spent on an Avaya or Polycom system. I think my system was more flexible and easier for my not so technically advanced fellow firefighters to use. As instructors, all they have to know is how to hook up the video camera and then to push the function keys whey they want to bring up the video.
As good as it works, there were a few things that I've never been satisfied with:
1) I want full 1024x768 resolution at 15fps. Because of the processing power of the day (the computer is circa 2004), I could only set my Screen Capture at 1/2 resolution form a 1024/768 desktop (512/384) at 10fps. The processor was a 2.4 GHz P4 and this used about 40% of the cpu. From trial & error that's about as high as I could go without causing problems with the other applications on the computer (PowerPoint, etc.).
2) I want to be able to capture the video from a visiting instructor's laptop (again at 1024x768). This will require either a VGA or an HDMI (720p) capture card by my estimation.
3) It would be nice to be able to use a voice activated 2-way audio from the remote computers so I could eliminate the push-to-talk (with muting) issue.
The first two are something I think can be overcome with the progress of todays technology. The third, I'm skeptical about (at least at my programming level which is very low) but that's ok because it bothers me a lot less.
I think that CPUs are finally getting powerful enough to compress 1024x768 at 15fps. Additionally, a multi-core processor should allow me to do this and still run other applications without any hiccups. Have any of you successfully used the Screen Capture Add-On at that resolution and bitrate?
This might be a better question for the ďCapture CardsĒ forum but have any of you successfully captured 1024x768 from an external source? The key to this is low latency. Many of the PVR solutions out there are set up for time shifting so they donít natively do real-time (zero latency) video easily (if at all).
Any ideas about how to improve how Iím doing my 2-way audio?
Any ideas or suggestions on how to improve the entire setup? Iíve successfully talked the Chief into a 5K budget in í08 for upgrades and I was planning on a new computer with a fancy capture card. I havenít upgraded the software from version 4.0 yet since itís still working pretty well. I figure that Iíll just install 5.5 on the new system and go from there. Any other advice would be appreciated.