[Etoys] Camera (was Re: [Trac #175] Squeak/Etoys needs packaging)

Diego Gomez Deck DiegoGomezDeck at consultar.com
Sun Oct 22 05:46:17 EDT 2006


Hi Jim,

Any good V4L implementation has to consider both cases (V4L1 and V4L2)
because there are still too many V4L1 drivers living around.

The squeak-plugin I implemented try to used V4L2 and fallback to V4L1
when needed.

Does the OLPC simulator support V4L? In this case, I can try to migrate
the plugin for myself.

Another question: What palettes are used in OLPC?

Currently the plugin supports: 

        - RGB24 - 24bit RGB
        - RGB32 - 32bit RGB
        - YUV420
        - YUV420P - YUV 4:2:0 Planar

But it's quiet easy to add support for another palette format.

Cheers,

-- Diego

> May need some updating; Jon Corbet implemented the V4Lv2 interface (the
> newer driver interface for Linux).  At this date, implementing the older
> driver interface was clearly a mistake.
> 
> I don't know how different V1 is from v2.
> 
>                                       - Jim
> 
> 
> 
> On Sat, 2006-10-21 at 11:48 +0200, Diego Gomez Deck wrote:
> > Hi Folks,
> > 
> > I already hacked a webcam support for Squeak at Linux, it's named
> > "Video4Squeak".
> > 
> >         http://minnow.cc.gatech.edu/squeak/3765
> > 
> > It uses Video4Linux, so I think is posible to run it in OLPC.
> > 
> > The camera also support some toys programming features. I also got
> > working the Intel(Play) USB Microscope (except for the ligth, the linux
> > module seems to be broken).
> > 
> > In the screenshot you can see 2 webcams (in fact is one plain webcam and
> > the Intel microscope) capturing at the very same time.
> > 
> > My work assumes the morph will survive the camera disponibility (you can
> > move the squeak image or a .pr to another machine without camera, or if
> > you connect more than one camera the order in USB stack can be different
> > in different boot-processing, etc) and it makes a good job trying to
> > reconnect.
> > 
> > In etoys vocabulary, you can find a "lastFrame" property.  This property
> > answer a SketchMorph that you can embed into a container and create an
> > animation. I used to create a project where one (etoys) script capture a
> > frame between time and time (normally 30 seconds) and put the frame into
> > a container. Another script just plays an animation (using the captured
> > frames) and instantly you have an accelerated-video (this type of videos
> > where a flower grows really fast, etc).
> > 
> > The plugin interface is relatively simple, so it's quiet posible to get
> > (the plugin) working in Windoze.
> > 
> > Attached is an screenshot showing the complete etoys-vocabulary.
> > 
> > Let me know if this helps.
> > 
> > Cheers,
> > 
> > -- Diego
> > 
> > > Am 20.10.2006 um 21:38 schrieb Zarro Boogs per Child:
> > > > Comment (by jg):
> > > >
> > > >  Really cool.
> > > >
> > > >  Does Etoys/squeak have support for cameras?  We got that running  
> > > > today...
> > > 
> > > 
> > > Well, there is "VideoFlow", which looks interesting, but requires a  
> > > plugin that might not have been ported to Linux yet:
> > > 
> > >       http://minnow.cc.gatech.edu/squeak/2411
> > > 
> > > And I just received some old bits from Tim Rowledge which once
> > formed  
> > > a Video4Linux plugin.
> > > 
> > > How would I access the camera? And until I get a b-test, could this  
> > > be simulated by a USB camera?
> > > 
> > > - Bert -
> > _______________________________________________
> > Devel mailing list
> > Devel at laptop.org
> > http://mailman.laptop.org/mailman/listinfo/devel
-- 
==========================================
 Diego Gomez Deck
------------------------------------------
 http://www.consultar.com/DiegoGomezDeck/
 http://diegogomezdeck.blogspot.com/
 http://smalltalk.consultar.com/
==========================================



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