Using projector via Wi-Fi from Linux laptop running Ubuntu 19.04 (Disco)

Question

A local bar hosts a programmer's meetup I organize. Recently they switched out their projectors such that the only accessible connections are now Wi-Fi (formerly I used a wire to HDMI/VGA ports.)

How do I go about connecting to a projector via wifi on Linux?

I'm using a Thinkpad T460, with Ubuntu 19.04 (Disco, the current version of Ubuntu).

$ NetworkManager --version
1.16.0

This answer describes solving the problem by installing Miraclecast on Ubuntu.

Unfortunately the MiracleCast PPA it references has builds available for many older versions of Ubuntu, but not for 19.04, which the question specifies.

Solution 1

gnome-network-displays is an application that might be applicable.

I can't find a binary of it for Ubuntu. So I grabbed the Fedora .rpm and made a .deb out of it:

sudo apt-get install alien dpkg-dev debhelper build-essential
sudo alien gnome-network-displays-0.90.1-0.fc30.x86_64.rpm

Then installed it:

sudo dpkg -i gnome-network-displays_0.90.1-1_amd64.deb

It needs a shared library that I didn't have installed:

sudo apt install  libgstrtspserver-1.0-0

Then run the application:

gnome-network-displays

This opens a GUI window, and correctly lists my home Roku as an available video streaming sink. Trying to connect to that gave an "Error" dialog (no other content.)

(See avif's answer for a suggestion of how to fix this error)

Solution 2

Just for future viewers, Jonathan Hartley's answer works as far as installing gnome-network-displays and you can do this to resolve the error that happens:

• Go to: https://github.com/sdroege/gstreamer-rs/tree/master/gstreamer-rtsp-server

• Install the listed packages, at the moment:

$ apt-get install libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev \
      gstreamer1.0-plugins-base gstreamer1.0-plugins-good \
      gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly \
      gstreamer1.0-libav libgstrtspserver-1.0-dev

That's it!

Note that this is still experimental stuff so it's slow & unstable.

Comments

[Giacomo1968]

Please edit your question… This is interesting: Do you have any details on the make and model of projector? As well as what the exact version of Ubuntu yo are using?

[Jonathan Hartley]

My source details added. For the projector, I'll have to visit the venue later today...

[harrymc]

Use nmap while in the shop to find which ports are open on the projector, which can give a hint. You may also try the procedure in this answer which involves installing miraclecast. As a remote possibility for an Epson projector, you might try in Chrome the extension Epson iProjection.

[Jonathan Hartley]

Thanks @harrymc, I'll try those things out and report back. I'll try them at home first, on my Roku, so I understand how they are meant to work, then I'll try them in the venue with the projector I actually want to use...

[Jonathan Hartley]

The miraclecast ppa doesn't have a build for 19.04 (disco) :-(

[harrymc]

Miraclecast has been open-sourced with FAQ. For installation from source see example1 and example2. Don't forget to check hardware support.

[Jonathan Hartley]

Thanks for that. I have it installed now, but I'm struggling through the instructions on how to use it. :-)

[Jonathan Hartley]

miraclecast author comments that as of Dec 2018 "miraclecast as a source (ie sending computer picture to external display) is still a WIP" github.com/albfan/miraclecast/issues/4#issuecomment-44722204‌​7 - I'm continuing to dig.

[Jonathan Hartley]

There is a branch which intended to address this issue, but it was HUGE (10,000 lines of diffs) and addressed several large issues all on one branch, and the branch persisted since Sept 2016 to 2019 (!) Surprising no-one, the branch never got merged, has massive conflicts, and is abandoned: github.com/albfan/miraclecast/pull/172

[Jonathan Hartley]

The miraclecast repo has a wiki, that lists source implementation as WIP github.com/albfan/miraclecast/wiki/…

[Jonathan Hartley]

On Apr 29 2019, a commenter asks the project author "What is the status of the WIP on source side Miraclecast? I have tried it and end up with an error...", to which the response was "It is not working for me too."

[Jonathan Hartley]

OP here. I'll try this out in the venue, with the projector I actually want to use, and report back.