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

[Jim Gettys]

On Sun, 2006-10-22 at 11:46 +0200, Diego Gomez Deck wrote:
> 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.

Good.

> 
> Does the OLPC simulator support V4L? 

No.

> In this case, I can try to migrate
> the plugin for myself.

The easy way to get close to the hardware until we can get you a sample
is to get a USB webcam of somewhat similar characteristics that uses
V4L2, and confirm it works on Squeak/etoys under a current Sugar build
(the environment can be built and tested on a conventional desktop).

> 
> 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.

Jon Corbet can comment on the formats we support.
                                           - Jim

> 
> 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
-- 
Jim Gettys
One Laptop Per Child