Hello.

I tried network streaming by HTTP protocol and I have fast local network 1Gbps but it has 4 seconds delay always. How can I reduce this? (max 1 seconds)

Is an i3 laptop enough for about: 4 network 720p streaming (4 client is connecting to it) and 1 720p internet streaming? upload bandwidth is unlimited.

Can I stream to Ustream with vmix?

Thank you!

I do not think it's currently possible to achieve sub-1 second latency with current IP-based video delivery that isn't made for the professional/broadcast world. Most encoders are not designed for zero latency. If you had access to the underlying encoding parameters, say with ffmpeg, you might be able to tinker with it long enough to get the results you want.

RTMP has a protocol delay in it by design, 4 seconds is a likely minimum number you'll see for latency, especially with Ustream or providers like that instead of a self-configured RTMP server. Still, RTMP is not designed for low latency distribution.

For LAN streaming, vMix Desktop Capture is very simple and works with less than 1 second of latency. Also, if you have HDMI output you can maybe run your video over Cat6 cabling with the right adapters.