Streaming your screen with VLC

Let’s review the situation: you’re about to start your talk and you notice that your presentation has small text or fancy colors (like yellow on white). You know that half of the room will be upset.

But you also realize that 98% of the room has a laptop open, and everybody is connected to the same wireless network; it’s time to multicast!

server side

Open a terminal and enter this command:

1cvlc screen:// --screen-fps=10 --sout '#transcode{venc=x264{keyint=60,profile=baseline,level=3.0,nocabac},vcodec=x264,vb=150,scale=0.5,acodec=mp4a,ab=96,channels=2,samplerate=48000}:rtp{mux=ts,dst=239.255.0.1,sap,name="Live streaming"}'

This is invoking VLC in “command-line mode”, using the screen as input (limited to 10fps, this are just some slides…) and some strange character sequence describing the output.

The output-magic is something like this: “#transcode{…}:rtp{…}”, so we’re looking at a 2 step sequence: a transcoding and then a streaming.

The transcode is using x264, is scaling to half the size (I’ve added this because I don’t need the FullHD quality of my desktop), and a low-quality audio (most probably, you don’t need this either).

The streaming is telling VLC to do RTP, to a multicast addres (239.255.0.1), enabling SAP (announcing the stream), and setting the name.

client side

On the client side, just start VLC and you’ll find your stream on “network streams (SAP)”. Just double click to let it start.