Tablet as secondary desktop display

[trinibwoy]

Does anyone have experience using a tablet as a secondary display? It would be nice to have skype or system performance monitors running on the tablet while running full screen apps/games on the primary monitor.

I assume this is feasible with miracast and other screen cloning tech out there supporting mobile devices.

 

[Zaphod]

The problem with most Wi-Fi Direct (all?) capable tablets/phones is that they're not set up to function as recievers using Miracast (even though they probably could). The solutions I've seen all need root/custom roms and have only been able to do mirroring, not extended desktop.

I haven't looked at custom software in a while, but maybe something like Splashtop or its ilk may have something.

Edit: Same goes for TVs, just the other way. But they probably also lack the required real-time encoding hardware. I'd love to be able to mirror my living room TV to my tablet (or even to another TV), but that's probably not going to happen anytime soon for the manufacturers' fear of running afoul the content (and content delivery) businesses. Strange how limited commercial use cases also limit what would probably be both cheap and feasible. Perhaps in a couple more years stuff like this will be ubiquitous.

 

[trinibwoy]

Isn't it just software? Why would a tablet be able to transmit but not receive a Miracast feed? I'll try out Splashtop later.

 

[Zaphod]

Why? Limited commercial use cases, I assume. I.e. Google wants you to use their services, so what do they get from people using "their" tablets as a secondary display? And I'm sure there are still some cost of implementation, licenses, certification, etc.

Then there is platform support. The providers may want to differentiate between products capable of either sending or receiving for commercial reasons as well. As a device maker, do you have any incentive to pay for that? And for third party support to emerge, there probably needs to be some source code out there as well. (IIRC, Tegra 3 devices were the only ones working last I looked.)

So while it may be "just software", it's obviously not just software.

 

[trinibwoy]

Fair point. As long as the device is wifi enabled a third party will step in to address the need just as they've done on PCs.

 

[Zaphod]

I got Splashtop to do what you want on one of two PC I tried it with (Win 7/AMD) but not the other (Win 8.1/Nvidia). YMMV.

Clients tried were Android and Win 8.1 tablets.

 

[Blazkowicz]

An RDP client should do the job, I guess that Splashtop is pretty much that (remote access software) but there's a strong software licensing issue.
Perhaps it's working above on Windows 7 Professional or Ultimate and not working on Windows 8.1 "Home"?

Windows "Pro" at best barely lets you have two concurrent users (local + remote) which is useful for troubleshooting/user assistance purpose. Else, the official mantra is you need Windows Server 2008 or 2012 and a special remote desktop license per client.
If that theory is right, that Windows 7 which accepts one client wouldn't work with two clients.
Still, some software could ignore or bypass the Windows licensing (simply install some Windows or Linux in virtualbox or VMWare.. host Windows won't know/do something/care about it.)

Client/server programs are another : for example performance monitoring software that would include a web interface (i.e. a web server). Access it from a web browser on the tablet.
Likewise, web based or not (or both) there's some other software where a back-end can run on the PC and a front-end on the tablet : torrents, music players.

Miracast or whatever it's named could be great if you can have a "dummy" secondary monitor whose output is beamed through the network. (at worst, you would plug some stupid resistors in a VGA or DVI connector to make the PC think there's another display)
But compared to a "real" remote session or client/server software, I fear that any interaction with the software displayed on tablet will steal focus from your full screen game (not a biggie but still ). But mainly this wastes wifi spectrum. In the near future maybe Miracast / Wifi Direct would be sorted out and you'd plug one USB Type C cable into the tablet which gives you power, USB2, USB3, and good wired ethernet at the same time.

 

[Blazkowicz]

Why? Limited commercial use cases, I assume. I.e. Google wants you to use their services, so what do they get from people using "their" tablets as a secondary display? And I'm sure there are still some cost of implementation, licenses, certification, etc.

Then there is platform support. The providers may want to differentiate between products capable of either sending or receiving for commercial reasons as well. As a device maker, do you have any incentive to pay for that? And for third party support to emerge, there probably needs to be some source code out there as well. (IIRC, Tegra 3 devices were the only ones working last I looked.)

So while it may be "just software", it's obviously not just software.

The Wii U does it but it's a proprietary, specific system.
Nvidia Shield is likewise advertised as a system that receives a streamed display, ditto SteamOS / Steamboxes (not sure if the latter only works with Steam games or something). But I have no idea if you can even stream a Windows desktop (cloned). That would make some sense, as the Windows desktop is 3D accelerated these days so it should be like a game, amiright :smile:

Yet both nvidia and Microsoft don't want a true "multi-user" remote ability, as for several grands they want to sell you Windows Server, RemoteFX, Geforce GRID etc.

If you were to run linux on the desktop PC, you have no access restriction whatsoever. Install a ssh server on the PC, an X11 server and ssh client on the tablet and that's enough to run anything on the PC from the tablet, albeit a bit slow for certain things and without 3D support (perhaps when "Wayland" gains use on the linux desktop, some seamless RDP / Miracast stuff will stream 3D apps as well).
With X11 (often derided as prehistoric protocol full of useless legacy cruft and incurable performance problems) there's still some nice stuff like drag'n'drop working between two remote apps. Or well, I was surprised to see it work. You can even have a "tray icon" from a remote app available locally I think.

But obviously there aren't quite as many games on Linux and Wine sucks.

 

[Zaphod]

Miracast or whatever it's named could be great if you can have a "dummy" secondary monitor whose output is beamed through the network.

That's exactly what Miracast does. It's basically peer to peer wireless HDMI. The underlying tech isn't that much different from other desktop streaming, except for the DRM layer and that it is seen (by Windows at least) as an independent monitor.

(at worst, you would plug some stupid resistors in a VGA or DVI connector to make the PC think there's another display)

Some trick may be necessary for this to work on Win 8. It seems the reason that existing remote desktop solutions don't work is that Windows has gotten "too clever" when it comes to hardware detection. It's completely EDID based now.

When switching to extended desktop mode in Win 7 without a secondary monitor attached, it does add in a "virtual" monitor (Display device on VGA) that can be exploited to wirelessly extend the desktop. In Win 8, if there's no physical secondary monitor, nothing happens; and thus all you get from desktop streaming is a clone of the primary.

But I have no idea if you can even stream a Windows desktop (cloned). That would make some sense, as the Windows desktop is 3D accelerated these days so it should be like a game, amiright

Yes. If you Alt-Tab or the game crashes with steam streaming, you may end up with the desktop. Cloning isn't what trinibwoy was asking about, though. Cloning is easy. Extending, so that the tablet/receiver/whatever can act as an independent display is much more finicky to get going.

 

[Blazkowicz]

(if we can get back to an "extended desktop" with a second display, what I've written about multi-user remote is off-topic)

Seems like you now need an EDID dongle (that you may need to build yourself). But I don't know if Windows will be pleased with that.
That's all pretty amazing, native Miracast support was one of the points of Windows 8.1.
I shouldn't have assumed anything about Miracast either. Should work on anything ethernet? Wrong. It's Wifi Direct only (i.e. fancy ad hoc). Damn.

At least those locked down aspects make it harder for other household members to steal your redirected outputs I guess.

 

[Zaphod]

One of those dummy VGA dongles that the folding (bitmining, whatever) crowd uses to get their non-primary cards to activate headlessly might do the trick. Being VGA it would probably limit what the virtual/wireless display could be used for a little, but no worse than what's just working on Win 7, I guess.

Otherwise, we'd just have to wait for the ability to work as a Miracast receiver/sink becomes ubiquitous on anything with a decently sized display. It just might be. You can hardly buy a TV without it these days and more PC monitors released are supporting it by the day.

For tablets, though; I don't really see any convincingly broad commercial use cases for the manufacturers to bother any time soon. But eventually it might be just so common that it's more of a "why not?" than a "why bother?".

 

[trinibwoy]

Yes. If you Alt-Tab or the game crashes with steam streaming, you may end up with the desktop. Cloning isn't what trinibwoy was asking about, though. Cloning is easy. Extending, so that the tablet/receiver/whatever can act as an independent display is much more finicky to get going.

Yeah I was able to get cloning up and running pretty easily with the Splashtop app. It even supports hardware acceleration which is cool. Performance is very good at 1080p for desktop usage and the mouse/touchpad/keyboard simulation works fine. It even sends audio to the mobile app.

Just need to find a way to do the same as an extended desktop instead of cloning. Don't even need interactivity as that could mess with application focus on the primary machine.

 

[Zaphod]

If you have a Win7 machine acting as the Splashtop server:
-Hit [Win +P] and choose "Extend".
-Enter "Screen resolution" from the desktop and adjust the resolution/location of the extended desktop (i.e. tablet).
-Then on the client (tablet) choose "Switch desktop".
-Voila.

 

[trinibwoy]

It's Win8 but I'll try it out. Thx.

 

[Zaphod]

Let us know if you figure out something that works for Win 8/8.1 as well.

 

[trinibwoy]

Tried both iDisplay and Splashtop to extend a Win 8.1 desktop to a Galaxy Tab 3 running KitKat. Results were mixed with neither providing a complete solution.

Host Cpu is a 4Ghz quad-core Haswell.

Splashtop
+ Performance is good. Seems to support hardware encode/decode.
+ Low cpu usage ~8%
- Does not support full screen applications (dealbreaker)

iDisplay
+ Performance is acceptable but not as good as Splashtop. Good enough to host widgets but not recommended for interactive app.
+ No issues with full screen apps
- CPU usage is very high at 25% (consumes 100% of one core). This has a tangible performance impact on gaming fps.

 

[Blazkowicz]

For tablets, though; I don't really see any convincingly broad commercial use cases for the manufacturers to bother any time soon. But eventually it might be just so common that it's more of a "why not?" than a "why bother?".

One example I could often read on websites and wikipedia : for streaming video from a cable box to a tablet. Or around here, DSL TV boxes (provided by ISP) are very common and serving about the purpose of US cable boxes.

ISP even "give away" a cheapie tablet to new customers sometimes.
Of course, the commercial reality of the feature depends on the renewed deployment of cable/DSL/fiber receivers, which would take its own time.