Video Streaming/Encoding Issue (I'm new to this)

[redfield]

Hello everyone -

I have a business need to do some streaming/encoding via VLC, and I was hoping I could get some insight on what I need to do from the pros. Please excuse any vagueness that may be apparent in my questions, as I'm not entirely comfortable with the specifics of what I'm talking about.

Basically, I have 3 machines. From machine 1, I need to take a screen capture and stream it to machine 2. Machine 2 then does the necessary video conversion to mp4 format, then streams it to machine 3, which ultimately displays the stream (the machines in question are all VMs, if that makes a difference). Describing what needs to be done sounds simple enough, but I'm pretty confused as to how to go about doing it. I've been looking at the command line documentation, but much of the terminology is confusing to me, and so its of little help.

I was given a command line script that I was told could be modified to suit my purposes. It is as follows:

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cd "C:\Program Files (x86)\VideoLAN\VLC" vlc.exe -vvv screen:// :screen-fps=10 :file-caching=0 --screen-width=640 --screen-height=480 --screen-top=200 --screen-left=400 :sout=#transcode {vcodec=mp4v,vb=3500}:duplicate{dst=rtp{dst=127.0.0.1,mux=ts,port=7100}} :sout-all :sout-keep

What I'm told this does is that it will locally stream a capture of my screen, but it doesn't seem to display anything (VLC starts up and plays, but no image is displayed). As I said, I was told I could use that script as a starting point for what I actually need to do (in bold above), but I don't know how to do it, and I don't have the time to experiment, unfortunately.

Thanks for any and all help that can be provided!

[b-frame]

Why do you need 3 machines? This doesn't sound rational to me. The computer which captures its screen will have to encode the video anyway. I think it's not possible to strean absolutely uncompressed data with vlc (that would need a lot of bandwidth). So why not encoding the video only once (like you already do with your command line). By the way, you should change the dst to the ip of the receiving computer or to a broadcast or multicast address.

[redfield]

From what I understand, the video conversion part is really taxing on the machine that does this currently, so the idea was to seperate the video conversion out onto its own VM, as the VM that initially sends the stream and the VM that ultimately displays it both do other things. The intent of the video conversion on a "middleman" VM was to hopefully lighten the load on the other two.

But what you're saying is that the VM that displays the stream is going to have to do the video conversion regardless?

[b-frame]

Video encoding needs lots of cpu power, this is true. But just a little example for the size of uncompressed video:

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resolution * size per pixel = size per frame 1280 * 1024 * 3 = 3,75 MiB

So if you want to livestream uncompressed video of a typical desktop resolution at 10 fps, you need 37,5 MiByte/s = 300 MiBit/s. And in reality, you will need even more, because of error detection and correction and lost data packets. Also, vlc doesn't support streaming uncompressed video, AFAIK. So you will have to make the first vm to encode the video and the second one to decode it.

[4NeR]

I have been trying to figure out the same thing for weeks now. There is a program with (Some of) the same features as VLC. Unreal Media Server http://www.umediaserver.net/umediaserver/index.html This has uscreencapture. The software is a little complex for me, but I do have it functioning. (Just not the way I want)

Ideally, It would be nice if VLC could be used as an input to other programs like Flash Media Live Encoder or Vidblaster. Programs that do this are Webcammax, Manycam, and Uscreencapture. Finding the connection between two computers is where it is difficult.