MiracleCast – Wifi-Display/Miracast Implementation

by tosh • 4 years ago

151 39 4 years ago

rektide2• 4 years ago

Kick ass to see progress continuing on this great Miracast implementation (Miraclecast). It seems to have been one of the ongoing sticking points that Linux just never quite got going, in spite of a couple tries.

It's unfortunate the industry as a whole never really got their stuff together on this- while I like the thicker client model that, say, a Chromecast has for many reasons (not trying to stream media live is a win), having streaming media as a baseline tech seems straightforwardly sensible & universal, and we probably would have advanced wifi & streaming considerably if this had started seeing wider adoption. It was a reasonable enough wireless-cable-substitute.

There's a PR for getting Miraclecast working as a source for external displays, which would be a great addition. https://github.com/albfan/miraclecast/pull/455

FeistySkink2• 4 years ago

Gnome Network Displays seems to be working fine here. Including virtual monitors. I use it regularly to cast to my TV including videos with sound. The latency could be better though.

sekh60• 4 years ago

Is there a way to enable compression on it? That may help with latency depending on the root cause.

gjsman-1000• 4 years ago

Miracast was cool... while it lasted. It had some issues as a standard though (one of the biggest being no maximum latency). Apple never supported it (AirPlay), and Android only supported it from 4.2-5.0, since being replaced with Google Cast (and as ComputerWorld sarcastically put it, this was "to the immense disappointment of approximately seven people"). Miracast is still functional on Windows and Linux... but how many people use it?

The best effort, though little known, was Microsoft selling a wireless stick for $49 that would connect to your TV and only supported Miracast. However, the latency was never near as good as Microsoft portrayed (watching a movie over Miracast generally isn't fun). They still sell it apparently, but now only for business uses: https://www.microsoft.com/en-us/d/microsoft-wireless-display...

tokamak-teapot• 4 years ago

Why would latency be a problem with video? Or is the audio separate and not latency compensated?

giantrobot• 4 years ago

If you have video-only content like a presentation you're fine. The moment you've got content with audio, like a movie, the AV sync issues are intolerable. I had one of the Microsoft adapters and I'd also see dropped frames and stuttering video. That was when I could even get the thing to connect. Apple's AirPlay isn't perfect by any means but it's a far better experience than I've ever had with Miracast.

orev• 4 years ago

The MS Wireless Display Adapter is amazing for business use (PowerPoint, etc.). Mostly static content. They also even more silently released a 4K one recently, which may have resolved the latency.

Savageman• 4 years ago

I used Miracast with the Microsoft stick to watched movies and it was way better than competitors IMO.

someweirdperson• 4 years ago

and Android only supported it from 4.2-5.0

I can cast my android 12 tablet (samsung) to my tv (panasonic, running firefox-os). The tablet calls it smart-view, the TV vierra-link. At least vierra-link is just a different name for miracast.

kalnins• 4 years ago

Google dropped it from Android, but several phone manufacturers are putting it back in ever since.

squarefoot• 4 years ago

Could this be used to allow a bigger and faster embedded system share its big screen with smaller boards with no video output through WiFi, or Ethernet where available, so that each one of them receives a portion of the screen, sorta like a quad multiplexer used in CCTV?

stragies3• 4 years ago

In short, yes, but the exact (very long) answer depends on whether you have a gfx-card in the (beefy) 'compute-machine', whether you use X11, or Wayland, Gnome or not, HW-encoding available etc. And that is on the server side. Clientside this also depends on whether you can install arbitrary software, or are limited to e.g. the DLNA-Implementation of e.g. a TV, when it comes to launching/pushing the streams of each quarter.

You should be able to use `ffmpeg` or `gstreamer` to construct pipeline(s) to screenrecord, pump out 4 TransportStreams in as-lossless-as-possible-bitrate over UDP, and use DLNA/whatEv to instruct the client devices to display the appropriate stream.

If the GFX-Card(s) in the "BeefyPC" can render 4 heads. then this will nearly work ootb with miraclecast.

axytol• 4 years ago

Interested to know if anyone can share what sink devices they use to drive the external display? My intention was to achieve something similar via VNC/nx and use a RaspberryPI ZeroW driving a TV via HDMI input.

amelius• 4 years ago

Why not use VNC's protocol, and e.g. allow your screen to be displayed in a web-browser too?

askvictor• 4 years ago

Microsoft and other vendors have built-in support for Miracast; I think a small number of TVs might too. VNC is a remote desktop protocol; Miracast is more of a networked display cable.

rcarmo2• 4 years ago

Also, VNC is hugely inefficient in comparison with more modern protocols.

joshu4• 4 years ago

It would be neat if there were userspace Miracast framebuffers. Could have a larger number of information displays around and just send images to them occasionally without having to have run X for each, or whatever.

vorpalhex• 4 years ago

Especially with the flood of mediocre but very cheap and thin "portable" displays that can be powered over USB.

joshu4• 4 years ago

Yes, that would be lovely.

stragies3• 4 years ago

If I understand your goal correctly, would EVDI (Extensible Virtual Display Interface) not be a possibility for you? EVDI allows to create "virtual heads", that you could then conceivably cast to external displays via `miraclecast`, VNC, etc.

It was originally created to support some ancient USB graphics card, but can be used independently off any specific hardware.

https://github.com/DisplayLink/evdi

joshu4• 4 years ago

That's a kernel module. Why should I need that? I just want to tell some network device to display a PNG or whatever.

akerr• 4 years ago

This would be handy as an OBS output. I wonder how well it builds and runs on macOS?

ysleepy3• 4 years ago

Microsoft's 4k wireless display adapter works great with reasonably low latency.

Chromecast has so much latency on my tv, that its impossible to use mouse and UI while looking at the tv.

And miracast just works with windows 10, its built in. Plus you don't need to be on the same network, good for guests.

aaaa4444• 4 years ago

Plus you don't need to be on the same network, good for guests

That means that the traffic goes through Microsoft's servers? Might be a privacy issue ?

int_19h2• 4 years ago

Miracast also seems to work with most Android phones, with the notable exception of Google (who used to have it in Nexus and then killed it off to promote Chromecast).

peaslock2• 4 years ago

Plus you don't need to be on the same network

You mean in case of the Wireless Display Adapter? For Miracast you do need to be on the same LAN, right?

ysleepy3• 4 years ago

No, it makes a WifiDirect connection to the tv concurrent to your normal wifi.

rcarmo2• 4 years ago

This has been around for a while: https://taoofmac.com/space/apps/screencasting

Good thing to see it’s pretty much full featured now.

pmontra• 4 years ago

How much does casting video over Wi-Fi (especially 4k) affect the performance of the other Wi-Fi traffic in a house? I moved everything to ethernet cables recently, except phones and tablets and I have no more stuttering when watching videos. But that's only me. I wonder, what if there were other people around doing their own Wi-Fi traffic and watching their own videos?

t-3• 4 years ago

It will depend on the number of antennas in your client and AP and the wifi tech. MIMO and beamforming make interference less impactful, but that's offset by the increasing number of devices.

MayeulC• 4 years ago

A different altern@tive gor media streaming, dimilar to chromecast, is Nymphcast: https://github.com/MayaPosch/NymphCast

Both clients and servers are available, it also works at a higher level.

MiracleCast – Wifi-Display/Miracast Implementation

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