Livecoding with Qt5 on the Raspberry Pi

A quick Friday video. This is Qt5 with QML and OpenGL shaders, running a tool written by Baldand. (For the less coding-inclined among you, this is a nice live demonstration of the graphics programming you can do on the Raspberry Pi, showing changes made on the fly.) Lovely stuff. Thanks again to all you Qt devs!

98 comments

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This looks quite fun! Can’t wait to get my hands on one of these. In the meantime, it looks like it is time for me to get familiar with Qt…

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gr8!

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Excellent….please keep these tasters coming (and a possible hint as to when they will be available! ). Looking forward to getting one of these possibly more than I did when I saved up and got my second hand Newbrain when I was 13.

Bring on the game changer……

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You’re blowing my mind! Reminds me al lot of Winamp’s AVS…

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Awesome :-)

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AHHHHHHHHHHHHHHHH!!!!!!!
S I C K !!!
That’s AWESOME!!!

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R TT 4TW

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Eben’s reaction on watching this for the first time was “God! The raspberries are metastasising!” It’s a lot like what we see in our nightmares at the moment. :)

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A very worrying demo, especially when it got to the 2001 Starchild section… I’m just glad they didn’t start colourcycling there too.

Otherwise, just WOW!

:-)

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Somebody asked on that Airplay post if the Rpi could be used to create the kind of content in the underlying Cyriak video. I had my doubts, but now I’m not so sure. ARM core itself is questionable, but I think the GPU’s powerful beyond my greatest imaginings.

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I agree with Shaun, I need to start looking at Qt. This looks awesome!

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What’s the deal with the blue flickering? Is that a camera problem or a Youtube problem or something with the TV or the video drivers or what?

*this post has been edited by Raspberry Pi to remove the personal data of another user at the request of that user.

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It’s a thing that happens when you take video of TV screens unless you have a particularly whizzbang camera. (Give it a go at home to see what I mean!)

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It is actually the refresh rate that you are seeing. It just happens at a frequency that causes the lines to appear and they appear that color. You can also get a similar effect if you have a fan in front of a monitor.

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I cant wait to get #processing running on this

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Awesome, is that editor overlay on screen, or mixed for effect after?
So want to start playing with one of these babies!

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It’s a live overlay – no trickery involved.

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Neeeeaaat :D

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“Live” Programming interpretor

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I cannot get one SOON ENOUGH! I too am eager and ready to get “playing” on this guy.. BeagleBone is just no doing it for me, although it is nice… I am looking forward to the store to open up…

-SH

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And I thought I was doing well, getting four colours in a character space on a ZX Spectrum. Oh well, back to the drawing board… ;-)

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Seriously though, this thing just continues to astound me with its amazingness. You are a team of heroes for making this happen.

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Heh—I remember doing something like that on my spectrum. Funny thing is that I was trying (with _limited_ success) to get a colour render of the Mandlebrot set.

And now we see this video of the RPi rendering Julia sets (Mandlebrot’s cousins—pretty much computationally identical) in real time…

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Aaaah, getting really excited about the R-Pi. My Arduino is excited as well :).

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Looking great! Any word from the factory?

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It’s CNY week at the moment, so things have been pretty quiet. We’ll let you know as soon as we hear from them.

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Crosby, Nash & Young week??

Hang on a sec, while I get my tie dye t-shirt out of mothballs! :-D

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Chinese New Year

A time where a billion travel

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Does this factory produce 10000 only or will they continue? How long will it take after the first 10k were sold? I hope you will not wait until the first batch was sold and start the next production after that!?

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Why not? they would sell out in 10 mins :D

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I’m pretty sure the 10K will sell out very fast, but from the way hardware production works it most likely not feasible to “just continue producing”. The factory’s usually produce in batches, e.g they set up production, produce a certain amount of gadget X, then set up and produce an certain amount of gadget Y etc.etc.
So, you would basically have to send a Larger order to produce more units.
Problem here is, you most likely need to pay (at least a part of the cost) up Front. So producing 10K might require an investment of 200.000$ , producing 50K requires 800.000$ etc. (numbers completely made up).
The earnings on the first batch will allow for more/bigger orders after that i guess.

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Good grief, I hope we’ve thought of that……

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Dammit all, will you lot quit teasing us and just SELL the blasted things already!! :P

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Wow! When it start to say: “This is Raspberry Pi” I thought it would be a movie like “This is your brain… and this, is your brain with drugs!”. Almost that :). A trip on visual effects!!!

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A typical Chinese factory would shut down about 5 days before CNY and won’t be running fully staffed and properly again at least 10 days to 2 weeks after CNY. Today is the 5th day of CNY, so unless most of the production work had been completed before CNY…..

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Sweet, real-time coding.. If only apophysis could do that, it’d make everything so much easier!

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That is awesome, it kinds reminds me of the old Amiga and Atari ST demos with vectors and coloured bars etc. All it needed was some MOD music playing in the background and a scrolling message with ‘greets’ on it.

Is there any chance source code for that video could be made available with a tutorial? I’d love to have a play around with something like that, and the realtime aspect of it would surely impress the kids, being able to change things to make it do different things on the fly.

Rob

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I don’t see why not – I hope Baldand will drop in here at some point to talk about it a bit more.

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I’ll second Rob’s request. I remember the demos on the Atari ST and it looks like now I’ll be able to recreate a little of that magic myself! This whole project is amazing – I started at age 11 on a ZX81 and now software development has been my whole career. I want every boy and girl to have a Raspberry Pi!

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anyone else remember the Kent Team?

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Right on, the Titan of digital justice signing in…

Atari st rules..

I’m now 37 and write ps3 games for my sins!

Chris

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I love it!
There’s going to be some awesome old school demos. Just needs a soundtracker backing track…

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each blog entry gets closer and closer to the release. i can’t wait to see that headline.

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Enough raspberrytease already ! When will I be able to order 2 ?

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I really wanna buy it. Qt Rocks!!!

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When Raspberry Pi gets available probably many of us will not get able to buy one because I am sure they will be sold out in matter of minutes. Will a wait list or pre-order be available? Or will it be available for shipping to countries like Brazil?

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10,000 is definitely not going to be enough! When’s the second order going in? ;-)

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I cant see that I am going to get one, there are 9356 forum members and more than 100 visitors at any one time and as soon as the RP drops it will be on the front page of reddit and /. so I don’t think anybody has a good chance of getting one

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Did anyone else jump when you a new post :)

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Did anyone else jump when you saw a new post :)

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Do I ever! I swear I check the Raspberry Pi website 20 times a day. This must be what it feels like to be addicted to cigaretts… once when I get up, once with every meal, a fet times in the evening, and definitely once before I go to bed. I wonder if they sell a patch for this :)

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same, but sadly I don’t think my chances are particularly high when it comes to getting one of the 10,000 with the amount of coverage it will receive when it drops

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Of course they sell a patch, you can buy it here : http://www.raspberrypi.com/keyboard-sticker/ :-)

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That’s truly impressive. Both the Qt demo, and to see it running on Raspberry Pi and updating with so few pauses!

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This is truly outstanding! Can’t wait till it ships!

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Would be great to see a command line interpreter that runs system calls (like BASH or CSH) using that great overlay interface.

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[…] video of the $25 Rapsberry Pi computer’s code being updated live. That means changes in the code automatically get applied, as it’s running. Must-have-toy for […]

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Actually, that real-time Julia set demo’s a little depressing. One of the projects I was going to look into was getting Fractint running on the RPi—I remember sinking _days_ into that with my early PCs, and I thought like-minded kids might enjoy similar. Of course it probably won’t stop me, mind…

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@bananasdoom

Yeah. About thirty feet, too.

Can’t wait to make my virtual sketchpad a reality. XD

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I’ve been looking for something to help make abstract video to accompany music (looked into Processing and Blender so far) but if I can learn to use Qt and make it do :::this::: that’d be fantastic :-D

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Visiting this page every 30 minutes a day, I’m getting sick !
I can’t believe getting one of those Pi’s…

Its so damn awesome what you can do with 25$…

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Glad it’s not just me…my missus thinks I’ve got OCD

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What is the chip temperature at maximum load?

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Around 45C. We’ve not been able to make it go significantly higher than body temperature (and we’ve tried!).

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I’ve been wondering about the temperature for a while now. When reporting 45 degrees, is it a reading from an internal (bcm2835) sensor, or is it a surface temperature?

It’s very amazing to see the day where high-performance computers no longer require a 1000W dirty SMPS power supply, while noisy fans spin at 3000RPM to keep the chips below their 80°C critical point. Certain GPUs were even designed for a 120°C critical point, though they had clock stepdowns far before reaching that temperature.

Another question, perhaps more technical; the Broadcom2835 is advertised as a “mobile” media processor, does that mean it has some sort of “power saving”?

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It’s a package surface temperature. The package is pretty good at bringing the board and package exterior into thermal equilibrium with the junction temp in the die.

The 2835 does have power saving – it’s designed for low power. There are a variety of DVFS features on board, but we don’t really use them on the Raspberry Pi.

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Perfect

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Cool! , i’m getting a early-Amiga-demo-boing-ball-feeling, and i like it!

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I just kept thinking it’s the new generations
10 Print “Hello”
20 Goto 10
30 Run

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You don’t put ‘run’ on line 30. You use it as a standalone command. Putting run in line 30 would be redundant as line 30 is never reached due to the goto command.

I’m really excited about all this. That and the rumours that apparently the British government is scrappng ‘ICT’ in Secondary schools for something which actually teaches kids to Code! (Because any 8 year old knows how to use Microsoft Office)

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Oddly. “30 RUN” was taught when I was in first grade. They wanted us to get the feel for having an actual execute command regardless of the dummy loop.

Just FYI

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FYI people, you can do this with your PC today … Qt is available for Windows / Linux / Mac. So you don’t have to wait to play with it. And once you get your raspberrypi, you will actually know what your doing ;)

It will be lot easier to learn for your PC, but having something run standalone on such a low cost machine that all of us can get is what great !

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OMG! It’s awesome and realtime! I want it :D

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Is the board used for this the $25 128MB RAM version or the $35 256MB model?

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This is the B version. It seems most people wanted a B so the first production batch will be B (256Mbytes) only.

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Will the a board, the $25 unit, produce the same quality FullHD playback? Like the video says!

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Yes, it will. The only difference is that there’s no ethernet, less RAM and only one USB port.

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Well thank you very much for that bit of news. I was a little put off the cheaper board but think now that if it will perform to a similar standard with just the 128MB RAM then I can live with a single USB (it would be plugged in to a hub) and no Ethernet (USB wifi or USB Ethernet in said hub).

Any thoughts on RAM expansion as an option for future boards?

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Order date 5th/6th january (estimate from “we’ve started manufacture” post, which was written on a Tuesday, the post said “a couple of days ago”, no-one does business on the weekend…. so it would have been ordered on the Thursday/Friday…. so the 5th or the 6th)

manufacturing time: 3-4 weeks (read from article about it being manufactured outside the UK)

add time for shipping from taiwan….

second week of february rasberry pi delivery?

I am rather excited, can’t wait to get one of these into my AS DT coursework! I’m going to send in some pics when it is done.

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Need to add 2 weeks for Chinese New Year/|Golden week

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cows & cows & cows.
raspi & raspi & raspi.

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The one on the main page is the XMBC video – it should be the one on this page.

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That was a quick fix! Thanks.

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Any idea if there’s a good way to get Qt like this to play nice with plain old C? Don’t want to have to corrupt my views on C++ just to make cool things on the Pi. :) I know most C code will get swallowed by a C++ compiler without too many warnings anyway, but I’d still have to deal with the C++ API.
Thanks
Angus

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corrupting your views? can you elaborate?

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Making my have to use C++ at all. I know I’m in the minority here but I just don’t like it as a language over C itself, I’ve always found that it doesn’t let me do anything I couldn’t do in C except wriet fancier bugs.

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<– Still a fan of C classic and BASIC as well. I learned how to program in BASIC, and I learned how to learn languages in Pascal so while I love the variation available to various languages, I still default back to the classics when I'm stumped.

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This looks awesome. Just can’t wait to get my hands on one of these. Having dabbled with XNA and direct x and adapted a few bits of code from Open GL I kind of understand what he was doing there. An amazingly cool interface too for QT5. QT5 looks amazing can’t wait to give this stuff a try.

I bet Raspberry Pi sells out to geeks before going to any education establishment (other than the pre-sales). I know I’ll be buying and gifting ASAP. Just such a cool project

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Hm. Glad you posted this as it’s now got me interested in Qt. I’ve decided to pronounce it “Cutie” even though it’s supposed to be pronounced “Cute” purely because of the amusement that “Cutie Pi” gives me.

What can I say? I’m a wordplay fanatic.

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*giggle* cutie pi *giggle*

Cutie Pi
can’t say/read it enough :-P i like it

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It is general pronounced as “cute”.

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My wife is designing a Qt Pi sticker for the altoids tin I’m going to mount my QT grant board in. So I’m pronouncing it ‘Cutie Pi’ no matter what anyone else says :)

With all due respect to Gert the person who has already extended the board and from whom I will be buying at least three GertBoards [Kits?]!

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Read my first post CAREFULLY

=P

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Looks like a good basis for an Asteroids game !

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Thanks for linking to my video!

After a little while working with the Raspberry Pi alpha board connected to a big TV (driving it from a distance with a wireless keyboard) it became quite clear that I needed a different kind of programming environment for getting the most out of it.

I was inspired by Inigo Quilez’ livecoding environment (see http://youtu.be/CHmneY8ry84) and many of his shaders from the ShaderToy (http://www.iquilezles.org/apps/shadertoy/)

The livecoding approach turned out to be great for working with QML, which is naturally a very visual programming language, as well as quite easy to implement.

I’ve now published the source code for the app shown in the video at https://gitorious.org/quint

You should be able to run it on a desktop build of Qt5 (which you will need to build yourself I’m afraid, since it is still under development), or of course on Qt5 for the Raspberry Pi (http://wiki.qt-project.org/QtonPi).

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Excellent post James – thanks.
I’m learning a whole bunch here and I haven’t even got my pi yet. This bodes so well for the future. What a fantastic idea you guys are turning into reality – thank you!
And just to lower to tone a tad – JamesH, Troll Spanker! I can’t help but think of you in a whole different light now – thanks Liz

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Oops posted this against the wrong article in my excitement – should have been against “Libries, codecs, OSS” – apologies please feel free to delete and I’ll re-post

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Hi, is there any tutorial how to install and run Qt5 from scratch on raspberry pi? Do I have to install linux on board? I have experience with Qt on PC and I would like to know how to run it on pi, could I run Qt 4.8?

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