How to increase the performance for convergence use case with external screen?

  • I tested the convergence use case with an external screen, that is connected with a dongle, that uses Miracast over WiFi. In addition I tested the setup with and without a bluetooth keyboard with touchpad.

    I could manage to morror the sceen in a large desktop resulution. Unfortunately the screen ratio of the vidio signal (16:10') didn't match the ratio of the external screen (16:9). The vido signal was cropped.

    Further more I realised, that hte mouse respectively touch pad signals are processed with a sginificant delay. So it is allmost impossible to control the external display. I also wasn't able to activate the window mode with the tweak app.

    I think, it is not an issue of the hardware. My UBports developer device is Fairpgone 2. I compared the setup with LineageOS on a weak Wileyfox Swift developer device. The external screen with Sentio and LeenaOS are very smooth and the mouse pointer response has no realizable delay.

    How can I improve the performace of the convergence use case. Only with the delay, the tested setup is not usable for practice.

    Shouild I test a secenrio with a wired connection? Unfortunately the FP2 has USB-B and not the full implemented USB-C to connect an external screen with HDMI. Some recommendations and experiences?

  • The wireless display support is a bit experimental, and I'm a bit surprised you got it working on anything other than a Pro 5. It's hard to tell from your post what your exact configuration was, but using Miracast in combination with Bluetooth devices is problematic, as both rely on the same radio device, so you will end up with interference.

    If you want to use Miracast, the best solution for mouse/keyboard is to use USB for those.

    Remember also that this is independently written software, and not simply re-using existing software from Google on Android that's seen significantly more testing. If you want to see it perform better, the best way to do that is to test it, find where performance issue exist, and provide PRs to fix the code to perform better.

  • @dobey Thanks for your response. Even if I disconnect the bluetooth keyboard and use the FP2 as a touchpad, the mouse pointer reacts with a signbificant delay. I will re-test the scenario with a Superbook over USB-OTG, that I have ordered, but I'm afraid, that the screen will just be mirrored and not scaled.

  • The Superbook will likely not work. It only supports DisplayLink, which is proprietary and is not supported in UT.

  • @dobey Maybe the Mirabook, but this requires the full stack implementation of USB-C on the hardware side. I think, they won't support Miracast, yet.

  • The mouse lag is more of an issue with the wireless display than UT/Unity 8's performance.
    I also never got wireless display working on any of my UT devices but in my general experience with miracast (i.e. Android), it's really no ideal if an input device is involved, there's too much latency.

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