I am confused what NDI is doing in terms of image quality (bitrate I guess) in relation to target framerate. This is what I'm seeing:

  1. If I start an NDI sender and start sending frames at 144 fps target framerate, then the visual quality of the stream suffers and I get very obvious compression artefacts.
  2. If I start an NDI sender and start sending frames at 60 fps target framerate, the visual quality is a lot better.
  3. If I start at 144 fps and then change to 60 fps, the visual quality stays bad. I suppose it is not upgraded 'on the fly'?
  4. If I start at 60 fps and then change to 144 fps, the visual quality stays good and the output framerate also stays good?!

I especially don't get point 4. Apparently it is able to send a high quality stream at 144fps with no issues, but only if I start sending 60 fps or lower frames first, and then change the target framerate to 144 on the fly.

By "changing on the fly" I mean I do not create a new send instance, I just start sending frames with a higher framerate at a certain point using the existing sender.

What is going on here? How can I setup NDI such that I send 144 fps with the same quality as the 60fps stream? Or even better (cause I don't really need 144 fps): can I somehow increase the visual quality (bitrate?) of the video stream if I stay at or below 60 fps? Apparently it is able to stream the same quality at 144 fps so why not better quality at 60 fps?