Locked FPS? about ofxndi HOT 4 OPEN

What sender and receiver are you referring to?

The NDI frame rate is controlled by timing. The example sender starts with NDI fps at 30 and the receiver shows the NDI received rate (1920x1080/30 fps) as well as the rendering rate which should be the monitor refresh rate of 60fps. If you change the sender NDI fps with the 'F' key you should see the corresponding rate in the receiver.

The sender fps can be changed. The key function is "SetFrameRate(double fps)".

The Windows sender example, includes an example option to set the frame rate to 30 fps.

The Openframeworks example has the same option but it is not activated.

The default is 60fps.

If you still have trouble I would have to see your source code.

from ofxndi.

Thanks for the response.

I'm talking in particular about the example-sender-receiver in the repository.

My receiver says that it's being sent a 60fps stream and the sender application says the same but I'm also being told that it's only outputting 20fps.

The receiver I've built is the default one with #define BUILDRECEIVER enabled although I have changed it so that It's fullscreen by default.

from ofxndi.

Try the receiver version of the example with the sender to see if you get the same result. It shows both the NDI and receiving rate.

RGBA/YUV sending makes a significant difference. Set it to YUV.

"Readback" has less effect but should be left enabled. "Async" frees the sender/receiver from locking sync together. It does no affect fps a great deal but try it on or off.

Otherwise it could be a system setting. Nvidia has "Max frame rate".

Edit: I realised that you are already using the example receiver source. Is the "PETES-PRO (Shader output)" sender also built from the example source? If you have both example sender and example receiver working together I have something to compare with.

Somehow the render rate is being slowed, but I can't reproduce it. I can achieve 60pfs at 4K with YUV, Readback and Async all enabled.

from ofxndi.

I can reproduce the symptom to some degree by setting readback off (the "P" key in the example sender). In the source code of your sender, make sure that you enable it -

ndiSender.SetReadback(true);

The YUV option has the most significant effect. Before creating the sender -

ndiSender.SetFormat(NDIlib_FourCC_video_type_UYVY);

There is also a timing utility function that will reveal the bottleneck. It's in a namespace -

ofxNDIutils::StartTiming();
double elapsed = ofxNDIutils::EndTiming();

I can't suggest any more without further information.

from ofxndi.