[maemo-developers] [maemo-developers] Detecting N800 camera position

[From: Iñigo Illán Aranburu]

Hello again Tim!

I suppose my code didn't worked for you. It's something very strange
what's happening here... but also I think I can help you. When I first
discovered this gconfv4l2src stuff I really do many things to try to
achieve this thing. As I was trying to do it with python, I didn't know
exactly how to do it like I'm going to explain but in C it should be
straighforward. AFAIK v4l2src element implements the
GstVideoOrientation[1] interface. So with
gst_video_orientation_set_hflip function and polling sysfs entry you
should be able to make it work (not sure if its hflip or vflip
function). Also, I suggest you to watch more in-depth what's the problem
with gconfv4l2src. I think the kernel sends a message to userspace which
is injected by a daemon through DBUS, and this should be catched by
another daemon which modifies the gconf key. Maybe for some reason these
daemon dies or is never launched on startup. I'm sorry I can help you
more with the names of this daemons, but I think you should have
something wrong in your system.

Hope at least it helps!

Bye.

P.S: I know I said to you I would like to help on this project, but you
know, sometimes there isn't many time to be involved on this things.
Also I would be happy to see your project launching a first version and
maybe in the future colaborate on some parts.

[1]
http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-gstvideoorientation.html

On sáb, 2007-03-03 at 18:11 +0100, Tim Teulings wrote:
> Hello!
> 
> > you could also check:
> > 
> > /sys/devices/platform/gpio-switch/cam_act/
> > /sys/devices/platform/gpio-switch/cam_turn/
> 
> I'm really lost in detecting and changing camer position.
> 
> My application uses gstreamer but is not a GTK application and thus not
> actively using the gtk, gnome, osso,hildon infrastruture.
> 
> Using gconfv4l2src works in that I get an image but the video image does
> not automatically flip horizontally.
> 
> As a next step I tried to add a notifier for the gconf configuration
> value. But this does not work. The notifier callback is never called.
> Perhaps because I do not use a gtk main event loop.
> 
> As a next try I tried to use gconf directly to poll the state. But this
> does not work either.
> 
> After that I checked the /sys/-values and they change. So now I will
> regulary poll this values as "I don#t like it but it works" solution.
> 
> However how to I flip the video manually using gstreamer?
> 
> P.S.:
> And yes, image/video flipping does work in principle as tested with the
> video conferencing tool.
> 
> P.P.S.: If I got this working I will release a small, simple GUI driven
> camera application...
>