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@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 -
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