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Facts about Wayland vs X

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Re: Facts about Wayland vs X

#41

Post by alanctgardner2 »

VLM wrote: post #20

I've occasionally wondered as a crazy hack has anyone ever implemented the VNC window system? The API/interface is squirting out a stream as would be seen over the network on VNC? Client has full control? Much as the simplest way to get cross platform cross browser pixel perfect web page rendering is of course a really big imagemap and skip all that large, slow html and css stuff, the simplest way to implement a wind…

I've done basically this (technically RFB is the protocol VNC uses, but whatever). The team I was on makes an auditing tool that records RFB traffic, transcodes it into MPEG video and also does real-time compositing in RFB. Initially it was just static boxes to obscure stuff, but we started doing messaging as well, until eventually we had a library to write arbitrary strings to the screen. I always wanted to extend it to accept user input as well, but that ventured into X territory too much.

It's worth pointing out that adding new data to an existing RFB stream with any kind of speed is stupid hard. The server has the ability to send one of about 11 types of message, from simple - a bitmap or RLE - to stupid - hextile and tight are popular. The only way we found was to parse every message, update a frame buffer, then re-encode the updated framebuffer. Not to mention all of the clients and servers have slightly different implementations, so even though you should be able to implement a subset of the spec, you end up implementing the whole spec, plus kludges for every popular client and server. Particularly egregious is Jolly's Fast VNC, which is probably the best Mac VNC client, but it actively rejects servers which are within spec to accommodate one particular server the dev targeted.

/rant

If you want to see the actual RFB spec: http://www.realvnc.com/docs/rfbproto.pdf

Re: Facts about Wayland vs X

#42

Post by Someone »

sprash wrote: post #39
zqfm wrote: post #36

Earlier quoted context omitted.

As someone who has never used X's remote access, what are its benefits over VNC?

OpenGL commands sent over the network can be executed on the local graphics card via GLX.

And that, for instance, means that your simulation running on a huge CPU cluster that does not even have a GPU can run interactive graphics on your desktop GPU.

I am not sure whether that still is a big advantage nowadays, as the typical cluster is fast enough to do OpenGL in software, but 20 years or so ago, this was a big issue, as that huge cluster might have been a 4 CPU, 2 GB, 100 MHz machine, if you were lucky.

Re: Facts about Wayland vs X

#43

Post by smalltalk »

tome wrote: post #33
wmf wrote: post #30

Earlier quoted context omitted.

Quartz architect Mike Paquette: Why Apple didn't use X for the window system (2003) http://developers.slashdot.org/comments.pl?sid=75257&cid=673... In retrospect, Xorg developers like Daniel Stone actually implemented most of the hacks in that list and have come to regret it.

Cool link, thanks! What do you mean "regret it"? It didn't work properly/performantly?

Performant is not an adjective. Performantly is not an adverb. Niether is a word. Use real words when you write. Maybe write, "It didn't work properly / perform adequately," instead of writing nonsense.

Re: Facts about Wayland vs X

#44

Post by toyg »

zqfm wrote: post #36
belorn wrote: post #32

One key feature of X that Wayland refuses to implement is the concept of remote access. Everything is intended to be local only. For those "strange" users out there who want remote access, the developers replies has so far been to use VNC. Its kind of odd that remote access has been shoved to the side in this age of cloudiness and always connectedness. One would think that there existed better methods to remote acces…

As someone who has never used X's remote access, what are its benefits over VNC?

It's usually snappier, because the client has some insight in what it's displaying and so it can accelerate stuff here and there; it also allows for root-less mode, where individual remote windows appear as normal windows to the local OS, rather than being forced to live in a monolithic "remote desktop" window. VNC is basically like a movie player: the local OS doesn't really know what the movie is displaying (in conceptual terms), and it cannot interoperate with it in any meaningful way.

The problem with the X approach is that client and server both do a lot of duplicated work ("oh, you're drawing a window, lemme put a nice border on it for you!" "Er, actually I was going to draw a different border, sorry." "Oh, ok, fine, I'll do what you say") and use "standards" protocols that have been hacked to death over the last 20+ years. It's very inefficient (although somehow it still feels faster than VNC in many cases, don't ask me why) and very hard for developers working on graphic subsystems (toolkits, window managers etc).

Re: Facts about Wayland vs X

#45

Post by [deleted] »

smalltalk wrote: post #43
tome wrote: post #33

Earlier quoted context omitted.

Cool link, thanks! What do you mean "regret it"? It didn't work properly/performantly?

Performant is not an adjective. Performantly is not an adverb. Niether is a word. Use real words when you write. Maybe write, "It didn't work properly / perform adequately," instead of writing nonsense.

[deleted]

Re: Facts about Wayland vs X

#46

Post by bbatchelder »

smalltalk wrote: post #43
tome wrote: post #33

Earlier quoted context omitted.

Cool link, thanks! What do you mean "regret it"? It didn't work properly/performantly?

Performant is not an adjective. Performantly is not an adverb. Niether is a word. Use real words when you write. Maybe write, "It didn't work properly / perform adequately," instead of writing nonsense.

It obviously conveyed the author's meaning. Not sure what more you look for in a word.

Re: Facts about Wayland vs X

#47

Post by bbatchelder »

belorn wrote: post #32

One key feature of X that Wayland refuses to implement is the concept of remote access. Everything is intended to be local only. For those "strange" users out there who want remote access, the developers replies has so far been to use VNC. Its kind of odd that remote access has been shoved to the side in this age of cloudiness and always connectedness. One would think that there existed better methods to remote acces…

You should really read the article.

Re: Facts about Wayland vs X

#48

Post by dietrichepp »

wmf wrote: post #25
vardump wrote: post #19

Wayland is a critical technology for Linux desktop community. X11 has been a reliable workhorse, but its time is up - simply too much cruft accumulated over the years that's not even used anymore. Yet all of it needs to be continually supported, adding to complexity. No one uses X11 primitives for drawing apart from bitmap functionality - even repainting dirty regions (expose events) often involves sending over a new…

krh is working on a lossless "codec" that uses a rsync-like rolling hash that should provide good compression with no artifacts (as long as the app isn't too skeuy). http://people.freedesktop.org/~krh/rolling-hash&#x2F ;

...but why? In my experience, using H.264 to encode screen captures gives you extremely high quality video for reasonable CPU and network expenditures. Is the last 1% of video quality really worth it?

For a demo, you can try using FFmpeg + x264 using the x11grab input. It's very easy to adjust the amount of CPU used (by changing the preset) and the bandwidth (by changing the CRF, or by setting the bit rate).

Re: Facts about Wayland vs X

#49

Post by peterwaller »

smalltalk wrote: post #43
tome wrote: post #33

Earlier quoted context omitted.

Cool link, thanks! What do you mean "regret it"? It didn't work properly/performantly?

Performant is not an adjective. Performantly is not an adverb. Niether is a word. Use real words when you write. Maybe write, "It didn't work properly / perform adequately," instead of writing nonsense.

http://boingboing.net/2012/12/13/literacy-privilege-or-why-g...

Re: Facts about Wayland vs X

#50

Post by vacri »

derleth wrote: post #38
Zenst wrote: post #2

The part that really sums things up for me was: "XI) “But Eric, if X11 is so terrible why not just make X12 rather than a whole new protocol?” They did, technically anyway: http://www.x.org/wiki/Development/X12 One big problem with keeping it under the “X” umbrella: Anyone who cares about X would have a say in a future version of it. By calling it “Wayland” they avoid that issue. No one cares. Its an unrelated projec…

It's the Lisp Problem: If you call your new language by the same name as an existing one, even if you add qualifiers (such as Common Lisp or similar), people will think it's exactly the same and that no progress has been made. OTOH, if you make a minor change, but give the result a whole new name (Java vs C++, C# vs Java), people will think the result is meaningfully different and take it as a sign of major progress.

Perl/Perl6 as well.
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