Question / Help Lowest Latency Possible?

[jamanjeval]

I'm setting up a research study where a remote observer watches and interacts with a subject running a simulation.

I'm using Open Broadcaster to record and remotely mirror the subject's screen (running at 1080p/30FPS) and mono microphone to another computer via dedicated gigabit ethernet. I'm only able to get down to about 3-5 seconds latency. Is there a way to get it even lower? Less than 1 second?

I am recording and streaming, but have also tried just streaming. The system is running with a lot of headroom (GFX card, ram, CPU) I've tried downscaling and lowering the frame rate with no improvement. I'm encoding using NVIDIA NVEC

My set up:
PC (source and recording)
i7-4770K Haswell @ 3.5GHz
32GB ram
SSD
Nvidia GeForce GTX 680 4GB

Directly connected via Gigabit Ethernet (no switches, just a cable) to a MacBook Pro running RTMP server on NGINX and viewed locally with VLC.

 

[Sapiens]

You could try using x264 with tune=zerolatency, but there's always going to be some delay.

 

[Boildown]

Not sure that tune is available for NVEnc, try it with x264 encoding. Actually you could encode in three ways, in theory: x264, QuickSync, and NVEnc.

NVEnc has its own "low latency" presets that would seem to be of use here. x264 has the "tune=zerolatency" trick. I'm not sure about QSV aka QuickSync. You'll probably need to experiment to see which has the lowest latency.

Also check your buffer in VLC player. The larger the buffer, the longer video is stored up before being displayed.

 

[Lain]

Minimizing latency is something I'm interested in for the rewrite. It'll be doable through a few new techniques, but I won't be able to get around to it right away.