After trying various solutions - including DeskPad - I came up with a custom cross-platform (I'm on macOS, but assume it'll work elsewhere) solution that worked incredibly well on my 40" ultrawide monitor: OBS[1].
Having never used OBS before but knowing it was popular among streamers, I wondered if I could use it to (1) only share the specific applications I wanted to share and (2) share them at a resolution that people could actually read, without constantly being asked to zoom in.
I first tried setting up a virtual camera and sharing via my video stream, but it was laggy and the quality was so poor that people couldn't read what I was sharing. I quickly gave up on that approach.
Then I discovered Projectors[2]. By right-clicking on the main view in OBS and selecting "Windowed Projector (Preview)", it launches a separate window, which I can then share directly via Zoom, Teams, Meet, etc.
Whatever I drag into the OBS view is displayed in the Windowed Projector (similar to DeskPad), with the added bonus that I can choose to blur certain applications that might be dragged in. For example, if I open Slack or my password manager, the entire window blurs until I focus back on my terminal or browser.
It took a bunch of tweaking to perfect, but I'm very pleased with how well it works now.
---
Linux/X11:
#!/bin/sh
new_disp=:2
size="1600x900"
unset XDG_SEAT XMODIFIERS GTK_IM_MODULE
set - "$@" \
-noreset -br -ac -dpi 120 \
-xkb-layout us \
-screen "$size" \
"$new_disp" \
#
Xephyr "$@" &
sleep .5
export DISPLAY="$new_disp"
metacity &
urxvt &
(Script slightly edited & shortened, probably broke something :D)
This is great; though I have less need for it day to day now.
I used to have 49" 5120x1440 display. We started with Zoom, which under Advanced would allow partial desktop sharing. I would draw a 1920x1080 box and move windows in and out of the box.
We moved to Teams and Teams only supports Window or Screen sharing. DeskPad would work great for that situation. Create a virtual display, share it and then use it on right part of the physical screen, moving windows in and out as needed.
Currently, I use 2 Studio Displays instead of the 1 Wide Screen. When I need to share screens, I press a button on Stream Deck that calls displaypacer to set the resolution on the second display to 1600x900. When done, I press the button again and it toggles the resolution back to 5K. The resolution switching is instantaneous with Apple Silicon/Studio Display making it hassle free.
Why do change the resolution instead of the scaling?
I've gotten away with simply firing up OBS and "screen sharing" the virtual camera. Has worked fine on Zoom and Slack huddles, with the added benefit of giving me other things that OBS can provide: easy recording, scenes, text, source management, plugins, etc. For a casual conversation it's somewhat overkill, but when you're doing something more serious or formal, or need to switch between a keynote/Powerpoint and a screen share, or a video capture device, it's wonderful, and actually rather easy to get going in.
> and actually rather easy to get going in.
The other day I tried installing OBS on a Mac and this was not my experience. I couldn't even get it to recognize the built-in MacBook camera, much less share a screen or a mic or...
I've successfully got OBS set up on Linux in the past and managed to get a simple workflow running, but even that took a lot of fiddling to get started and I had the darndest time finding what I needed. The UI reminded me of GIMP—I'm sure I could eventually figure out how to work it and it probably makes complicated workflows possible in ways that simpler tools don't, but for a newcomer it has been overwhelming.
This is _genius_. I have been using RegionToShare in Windows to share only a section of a widescreen monitor, but didn't have a good Mac equivalent. Now I have something that may well work _just as well_ with Windows inside Parallels (need to try that ASAP, am on the "wrong" Mac now).
Edit: A quick test shows that yes, the Windows VM sees the additional display just fine--but, alas, Parallels doesn't let me pass _just_ one physical and that virtual display to the VM, so I can't have my "personal" portrait monitor unoccupied by Windows...
+1 for RegionToShare on windows. It's not perfect but it has made sharing on a 49" monitor much much easier.
The title could clarify it's for MacOS X.
Linux users probably already have some weird workflow with X11 virtual buffers to do this.
Personally I don't bother with a virtual display. I automatically set my display scale to 2x when I start screen sharing. I set that up with exec_before and exec_after hooks in xdg-desktop-portal-wlr[0]. In addition to turning off my notification daemon (so my email/instant message notifications don't pop up), my exec_before/exec_after scripts just run:
swaymsg output "MY-MONITOR" scale 2 # or 1 for exec_after
[0] https://man.archlinux.org/man/extra/xdg-desktop-portal-wlr/x...
This is how I do it under Sway (Wayland):
#!/bin/bash
swaymsg create_output OUTPUT=$(swaymsg -r -t get_outputs | jq '.[].name' | grep HEADLESS | tr -d '"')
# No need to reduce res, it defualts to 1080p #swaymsg output "$OUTPUT" resolution 1280x720
wl-mirror "$OUTPUT"
swaymsg output "$OUTPUT" unplug
When I was still in X11 land I used to just use Xephyr.
I just realized formatting is a bit broken. :(
Fixed:
#!/bin/bash
swaymsg create_output
OUTPUT=$(swaymsg -r -t get_outputs | jq '.[].name' | grep HEADLESS | tr -d '"')
# No need to reduce res, it defualts to 1080p
# swaymsg output "$OUTPUT" resolution 1280x720
wl-mirror "$OUTPUT"
swaymsg output "$OUTPUT" unplug
You can do code blocks on HN by prefixing your lines with four spaces.
#!/bin/bash
swaymsg create_output
OUTPUT=$(swaymsg -r -t get_outputs | jq '.[].name' | grep HEADLESS | tr -d '"')
# No need to reduce res, it defualts to 1080p
# swaymsg output "$OUTPUT" resolution 1280x720
wl-mirror "$OUTPUT"
swaymsg output "$OUTPUT" unplugFour spaces!? Absurd! Think of how many bytes you're wasting! In just your last code block your flooded the internet with 28 needless bytes!?!?!?!! If this keeps up soon we'll all just be downloading whitespace.
Only two spaces are needed: https://news.ycombinator.com/formatdoc
function trim {
sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//'
}
Oh, thanks! I remembered there was something, skimmed through https://news.ycombinator.com/formatdoc and completely missed it.
Ooh, creating a headless display and then wl-mirroring it is incredibly smart! Have been looking for something like this!
I use `xrandr --setmonitor` to create a fake monitor that only covers part of my screen. And I have some window manager setup to easily move my windows there (with awesomewm).
That's a good solution. I used xnest
Xnest is probably enough. I've used it for similar purposes a few times. Don't know the equivalent for Wayland though.
Xnest got replaced by Xephyr AFAIK. But same thing at the end of the day.
Yes, Wayland compositors like cage and sway can be nested too.
That said, with both the X nesting approach and the Wayland nesting approach, you'd also need to run the screencasting application itself inside the nested server, not the just the application you want to cast. If the compositor supports a way to create headless outputs (as sway and hyprland do) that is much easier.
It's not exactly the same, but as an alternative to what jauntywundrkind you can use V4L2-Loopback and OBS to create a virtual webcam and use that to share your screen. I find it really handy being able to switch between either just my cam, my desktop or both.
Yeah. On Wlroots or Sway, we can setup virtual displays pretty easily (swaymsg create_output, done). Run wayvnc, and both the other person and yourself connect over vnc or rdp to see what's over there.
Available May 2020, https://github.com/any1/wayvnc/issues/7#issuecomment-6256611...
For Hyprland, the command is `hyprctl output create headless NAME`
Small FYI: it’s just called macOS now
I think the problem I have is more so that people want my font sizes to be 3x what I have them. Usually I’m presenting a spreadsheet (financial statements and such) and people ask me to zoom in. Which I can but it breaks the whole thing and throws me off because I can no longer read my document anymore and I’m trying to present it. For that reason, I evangelize that attendees use the Zoom feature on their device if it’s too small.
As I understand the issue it’s not that font is too small on my device, it’s that Teams has a tiny viewport and so it gets shrunk down. Most people aren’t doing full screen. They have a sidebar for chat and such and a top bar of other options. These don’t leave much real estate for my presentation.
Would something like this help my problem or anyone know a better solution?
As someone often on the receiving end of screenshares, I cannot recommend enough that you do not maximize your shared window itself unless it's absolutely necessary. On a typical 15" laptop, 2/3 the width and ¾ the height is great. (for a 4K/5K monitor this will probably be even less). Even assuming everyone else has eyesight on par with your own, it's wise to leave room for the chat on one side and a toolbar on the bottom.
People can zoom, yes, but it's going to require scrolling which can be distracting even if it's set to "follow pointer" -- and your pointer may be zipping all over (like, going to the toolbar when the users are looking at a row near the bottom of the screen)
I know it is a challenge to limit yourself to a small canvas -- we all love using a big screen for certain tasks -- but I believe it's going to be easier and make for a more engaging and productive session when you control both the viewport size and the scroll position at all times. One nice thing about Zoom is that it is dynamic, so if you are sharing a window and you realize you need more horizontal real-estate for a certain part of your preso, you can momentarily resize your window for that, and then go back to a more manageable size when done, with no re-sharing needed.
OK, I have a series of steps you can follow:
- Start DeskPad
- Go to System Settings and set the resolution of the virtual display to 1920x1080 (just to be a standard size/resolution and not retina, saves on resources and hassle)
- Still in System Settings, set Accessibility Zoom to render a magnified version on the virtual display:
https://support.apple.com/guide/mac-help/zoom-in-on-whats-on....
- Resize the DeskPad window to be a nice little preview on the corner of your screen.
- Start your call, share the virtual display (which will be the zoomed version of what you are pointing at with your mouse)
I often call into meetings where I am also presenting twice. Once on my phone and once from my computer. I use my computer for sharing, audio, video, etc. I use my phone to see what the other people see. Shared screens are always difficult to predict. If you have a 4K screen, it will almost always get downsampled somehow for meetings… it can be too slow otherwise.
In my experience, the problem isn’t that the font is too small on your device, but rather that you’re sharing too much screen. Even if I’m sharing a terminal window (common for me), instead of changing the font, I try to make the window smaller. This has the same effect and is much easier to control. On the viewing device, the video you send it always scaled (either for a different resolution or viewport size), so it helps to limit the size of the screen/window that you’re sharing.
Telling viewers to zoom in if they can’t read anything sounds like you’re blaming them for the problem. If you have a different device connected, you might be in a better position to find a solution on your end.
> Telling viewers to zoom in if they can’t read anything sounds like you’re blaming them for the problem
yeah I wouldn't disagree, have been ignorant to the solution on this one. It's a recent concern as I'm new to Teams and working at a company with an older demographic than I'm used to so I'm kind of new to getting this request so much tbh. When people complain about having "aging eyes" my default response has been to zoom up to 150% but beyond that I can't even use my own computer as a presentation device for myself which is a showstopper, so my initial thought was tell them to use the Zoom, it's what you do on your phone to read small text, browser to read news, etc. and honestly I zoom in when I can't read someone elses screen (I've never asked someone to increase a font size mid-presentation). Part of the problem is the content kind of requires a lot of columns of data to be visible at once. Bouncing around from YTD to MTD sections by section kind of breaks the flow of the meeting, especially because while I'm presenting they are all individually consuming the content differently (one guy only care's about Margins, one guy only cares about Expenses, etc so it helps to have a lot on the screen at once and let them zoom into what they care about)
All said, I'm definitely going to try out all the suggestions here and see if I can figure out a better solution. Thanks HN!
+1 to learning how to share a window, doing it fast when you’re changing windows, and reducing the size of the window. It shows that you care for the audience.
I ended up buying a bigger monitor for screen share. For most purposes I prefer my setup with multiple 19" monitors running at 1280x1024 but it's a nightmare if someone with a higher desktop wants to share. I have found the bigger monitor nice for games also.
I am presenting SAP t-codes on a daily basis and can relate – especially for presentations I tried to show always only the most important things and use fonts like 2 or 3 times bigger, especially with monospace fonts not so easy to find good readable narrow fonts.
Yeah, if you create a virtual monitor with low resolution like 1280x720 or 1024x768 people will be able to see what you're sharing.
I like using FancyZones which is in the Microsoft PowerToys suite. That way you can snap things to a 1080p resolution part of your ultrawide screen. My other simple option is just open the laptop screen which is 1080p
I wonder if something like this could be done on Linux with xorg hackery (probably involving xvfb?). Definitely seems handy.
You can just start Xephyr, it gives you an X server in a window. Needs a few lines of setup around it to get a window manager or desktop session on that window.
I really like this concept. especially for the use case where I need to share my whole screen, but just want a "sandbox" of sorts to share. Typically have gotten around this with a secondary monitor that I share with, but that doesn't work when I'm on the go with my laptop. Will def be using this
This looks great - really useful!
I have always wondered how these virtual desktops work. A cursory looks shows that this is using some undocumented APIs. How do people learn they can create a virtual desktop in this way if the knowledge to do so is hidden/obfuscated?
Does apple allow distribution of an app that use these "private" APIs?
Is anyone aware of what mechanisms are there for achieving something similar in windows?
> Does apple allow distribution of an app that use these "private" APIs?
In the app store, sure, any other way, what can they going to do about it?
They could not notarize it, meaning users have to tackle bypassing the Gatekeeper?
It would be so nice if we could stop destroying the planet by dropping support for legacy Macs. Mine is a 2014 Air and I'll stop using it when it crumbles to dust.
Windows has a similar tool. But it’s two steps.
1. Set up a new virtual monitor (see https://github.com/itsmikethetech/Virtual-Display-Driver)
2. See virtual monitor using google chrome desktop.
I have an Intel MBP, so my first question is will this work on my legacy hardware? And my second question is will this act like a typical external display I connect to my MBP and set it on fire? As far as my experience goes, it's not behaving like an external display unless my CPU is occasionally pegged at 100%, fans are blasting, and my computer becomes intermittently unusable until I disconnect the display.
I used to have an Intel MB, mid 2010. I had to disconnect the hdmi cable so it can boot, otherwise it would just blast the fan displaying the apple loading animation. It died on 2022 when i installed an update that asked for a restart and i forgot to disconnect and went on vacation. RIP Intel MPs. Amazing beasts.
Zoom has this as a built-in feature -- you can share just a region you specify of your whole display. Share screen -> advanced -> "portion of screen"
Is it open source? Oh, no?
Oh lawd I’ve had to say ‘sorry you’ll have to bear with my ultrawide’ during pairing at least 10 times in the last week. You are a lifesaver.
Nice! I’m currently using https://www.appblit.com/screegle
It works well and has more features but I like having an open source alternative. Thanks
Just don't drag the DeskPad window to the virtual monitor
I’ve been using https://github.com/waydabber/BetterDisplay for this purpose. Does something similar and more. Works great!
I know it can create a dummy display, but can it create a window on the real display showing the contents of the virtual display?
That seems to be the flagship feature of DeskPad.
Which feature do you use? Would like to try it as well.
But not open source? I mean, its fine if its closed, but no point in linking to a github repo, and if so its not a like-for-like.
Edit: I see looking at the branches an old version was open source some years ago.
I need this. I have a 49" monitor and sharing the screen is such a pita
I have a 43” and keep my laptop screen open for when I need to share my screen. The issue is when I have to share code, because my font is huge in my editor. I could scale up and down I guess, but I really don’t like messing with stuff once I have it how I like it.
More and more I’ve gotten lazy and share my main screen. My editor is big enough for people to see, but browsers are an issue. I have less of an issue zooming those as needed.
Very cool. Does it require the "screen recording" indication to be up the entire time whether screen recording is happening or not? I don't see any info in the repo but I recall some previous solutions would effectively appear to be recording all the time.
EDIT: unfortunately it does. But if it's designed for screen sharing, it's probably not a big deal. Unfortunately there's no easy way to mirror on OSX without this, AFAIK. This particular issue is annoying for certain USB-C video adapters that create a virtual screen and mirror it over an arbitrary protocol.
Thank you for this - sharing a window makes drop downs and other things not work. I look forward to trying this out for a better solution.
what a briliant idea, most of my meeting i had to share my 4K screen with laptop pals and most of the time i had to zoom so they can see. now it's solved.
Nice. I'm testing it watching a YouTube video in "full screen" in its window, while also leaving room for a browser and email window on that monitor.
This is an excellent use case that I also often felt the need for.
You can remove all the YT clutter this way, have all the controls and keyboard shortcuts, and extensions like Video Speed Controller still functional while precisely controlling the position and size of the video. Would be great for following long lectures and tutorials.
any good solution for this for a Windows machine?
I use the pip functionality of Firefox for that. It works on every html video and ironically, you can make it full screen.
I use the “maximize video” chrome extension which may work for you. You can click on any video player and it will make that take up the whole browser window size. So then the video size == the browser window size. I use it to panel multiple videos around my screen (mostly for watching multiple NFL games at the same time).
I also use Better Touch Tool which supports keyboard shortcuts for arranging windows, I believe there’s a similar tool for windows. So for example if I want 4 equal sized windows (in each quadrant of the monitor) I can do it easily with keyboard shortcuts.
This is very useful, thank you.
Very nice idea! It would be nice to be able to do the same on Linux and/or Windows, too!
This has been possible on Linux (Wayland + pipewire) for a couple years now.
It has been possible on Linux for way longer than that, Xnest dates back to when it was still XFree86 rather than Xorg. Quick googling has Xnest and Xephyr mentioned in 2012 changelogs (X11R7.7), but those aren't even "creation" changelogs. (I can't easily dig up when they were created…)
This has to have been made for MS teams, right? It is unusable if youre screen is too large!
Cool! I usually have to share window-by-window, this may come in handy.
Having had to order whiteboards to airbnbs for offsites, yes this is cool!
Here is a related project I use to share selected content (usually single windows and my iPad) on a projector while teaching: https://github.com/benjones/presenterMode/
With my 6480 x 3840 (three 4k screens) desktop resolution, in Zoom I just select "Share a portion of screen", and I can resize the area that gets shared to something close to a common screen size.
I used that until we moved to Teams for all video calls. And it doesn’t have that feature :(
I’ve looked around for an app like this. But they’re all paid and the security prompts are a little scary.
As someone with an ultrawide monitor, this seems like a really neat solution. Thanks for sharing it!
What an intriguing idea. I wonder if I could do something similar on linux by placing a second monitor on top of my current one with xrandr.
On Linux, you can try Xephyr (https://www.freedesktop.org/wiki/Software/Xephyr/, https://wiki.archlinux.org/title/Xephyr). It's not as nice as DeskPad, but you can basically achieve the same thing.
Xephyr runs a whole new X server - it's not as easy to drag and drop an application into the nested server, it has to be launched with DISPLAY=:1.
It's too easy to just use OBS for this, in my opinion. Add the pipewire display capture, add a filter to crop it to a corner, stretch that container to fit the stage, open the window in the corner. Fairly simple.
So neat!
Wouldn’t it be nice if we could adjust resolution per window?
On a 4k monitor some applications have tiny text and icons, and no way adjust that I can find.
I like the idea! Rooting for whoever in the universe working on it! Meanwhile, I think you could actually "mimic" this by using OBS as a virtual camera and use multiple layers to selectively share windows. You can set an output video size, and scale different layers/windows individually.
I just went to Preferences and set the resolution of the virtual display to 1920x1080.
But doesn’t that affect ALL windows?