[SailfishDevel] Camera flash control. Wired to Qt level or not?

Artem Marchenko artem.marchenko at gmail.com
Sat Nov 16 16:22:32 UTC 2013 

I prepared the next test app, that starts searchAndLock() every given
number of ms and optionally does unlock() soon after it (not sure if you
have to unlock before starting the next searchAndLock() ). Plus you can
play with the search mode if Manual happens to be not good enough.

Anybody willing to try on real hardware? Preferably both in dark and light
environment (maybe flash starts in dark conditions only as Mohammed told).

Link to ARM RPM - http://bit.ly/videofla109
Or here's full source code -
https://github.com/amarchen/video-flash-trial/tree/v0.1-9/

Cheers,
Artem.


On Sat, Nov 16, 2013 at 6:05 PM, Mohammed Hassan <
mohammed.hassan at jollamobile.com> wrote:

> The point is not to be in continuous focus mode (CAF) because if you are
> in that mode
> then camera might not try to focus if it happens to have focus already
> (CAF mode = camera
> tries to focus all the time).
>
> In manual or fixed focus modes, camera will not try to focus all the time
> and will instead
> wait until it is instructed to focus and then it will do it.
>
> That is simply the reason.
>
> CAF focus is not guaranteed to be out of focus but manual is guaranteed to
> be out
> of focus ;-)
>
> Cheers,
>
> On Sat, Nov 16, 2013 at 05:58:30PM +0200, Artem Marchenko wrote:
> >  Can you explain why Fixed (manual) focus mode? :/
> >  Sorry to ask for details, it's a little difficult without the device at
> >  hand?
> >  Are you trying to tell that in a Fixed mode camera will seek for focus
> >  forever?
> >  Artem.
> >  On Sat, Nov 16, 2013 at 5:55 PM, Mohammed Hassan
> >  <[1]mohammed.hassan at jollamobile.com> wrote:
> >
> >  searchAndLock() should work as long as you are in a dark
> >  place (that's what LED torch is for ;-))
> >  and make sure the focus mode is set to fixed focus mode.
> >  Good luck!
> >  Cheers,
> >
> >  On Sat, Nov 16, 2013 at 05:35:47PM +0200, Artem Marchenko wrote:
> >  > I used to work a little with GStreamer in the past, it wasn't much
> >  fun,
> >  > though I was doing video processing, not just LED manipulation..
> >  > Oh well, I try searchAndLock trick, if it doesn't work, I'll need to
> >  > think if I am into diving to gstreamer or into waiting for the Torch
> >  > API. Technically, waiting for Torch is correct probably, I am just
> >  > driven by the opportunity to make the very first torch for Jolla :)
> >  > Cheers,
> >  > Artem.
> >  >
> >  > On Sat, Nov 16, 2013 at 5:28 PM, Mohammed Hassan
> >
> >  > <[1][2]mohammed.hassan at jollamobile.com> wrote:
> >  >
> >  > Hi Artem,
> >  >
> >  > On Sat, Nov 16, 2013 at 04:43:57PM +0200, Artem Marchenko wrote:
> >  > > Thanks, Mohammed.
> >  > >
> >  > > I know that torch mode is not supported, but ON mode is. So my
> >  > current
> >  > > workaround idea is to make phone think it shoots video with flash
> >  > mode
> >  > > ON (ok, we can even shoot video for real if needed). Assumption is
> >  > that
> >  > > video + flash mode ON should make phone record video with light
> >  > > constantly ON. Currently it doesn't work for me, maybe because
> >  > > assumption is wrong or maybe I am just using some api the wrong
> >  way.
> >  >
> >  > It will not work that way. There is a special mode for torch light
> >  > but it's
> >  > not yet been implemented.
> >  >
> >  > > 2nd workaround idea is to make phone seekAndLock all the time
> >  > causing
> >  > > flash to be ON. That is likely to result in a multitude of short
> >  > > flashes though.
> >  >
> >  > That can work but it will be slow "light bursts".
> >  > A 3rd option would be going even below GSTreamer and Qt and talk to
> >  > the camera HW directly.
> >  > This is harder -trust me- and will tie you to the hardware.
> >  > I am really sorry I don't have a solution for you :(
> >  > I can only promise it will be available soon in an update.
> >  > Cheers,
> >  >
> >  > > When you record video with the flash ON in a system camera app,
> >  does
> >  > it
> >  > > cause LED to have kith ON all the time?
> >  > >
> >  > > Artem.
> >  > >
> >  > > On Saturday, November 16, 2013, Mohammed Hassan wrote:
> >  > >
> >  > > Hi Artem,
> >  > > On Sat, Nov 16, 2013 at 02:48:30PM +0200, Artem Marchenko wrote:
> >  > > > Hi All
> >  > > > *Context*
> >  > > > I am trying to build a flashlight app, but the same question is
> >  > > valid
> >  > > > for any camera app that wants to shoot photos/videos in low
> >  > > light.
> >  > > > *The problem*
> >  > > > I am trying to control LED flash by setting flash mode to ON
> >  (api
> >  > > > confirms that ON mode is supported) and starting camera. Nothing
> >  > > > happens. I also tried actually capturing photo, shooting video
> >  > > and
> >  > > > seekAndLocking. I don't have a device myself, but kind people on
> >  > > IRC
> >  > > > told that only two short LED flashes happen (during seeking for
> >  > > focus
> >  > > > probably).
> >  > > > Could somebody, please, advise how to control flash in Sailfish
> >  > > OS? Or
> >  > > > maybe you could confirm that libhybris flash control just isn't
> >  > > wired
> >  > > > to Qt level?
> >  > > This is unfortunately not supported.
> >  > > The only flash modes supported now are: on, off or auto.
> >  > > Torch light mode is not yet supported but I assure you it will
> >  come
> >  > > in an update soon.
> >  > > I am not that familiar with Qt but I know it's a limitation of the
> >  > > layer underneath Qt.
> >  > > The best you can do now is to wait for the phone itself and tinker
> >  > > as you like and I am
> >  > > sure you will manage to do it :-)
> >  > > Cheers,
> >  > > P.S. libhybris camera wrapper is not used by sailfish. It might or
> >  > > might not work.
> >  > > _______________________________________________
> >  > > SailfishOS.org Devel mailing list
> >  > >
> >  > > --
> >  > > Artem Marchenko
> >  >
> >
> >  > > [1][2][3]http://agilesoftwaredevelopment.com
> >  > > [2][3][4]http://twitter.com/AgileArtem
> >  > >
> >  > > References
> >  > >
> >  > > 1. [4][5]http://agilesoftwaredevelopment.com/
> >  > > 2. [5][6]http://twitter.com/AgileArtem
> >  >
> >  > --
> >  > Artem Marchenko
> >  > [6][7]http://agilesoftwaredevelopment.com
> >  > [7][8]http://twitter.com/AgileArtem
> >  >
> >  > References
> >  >
> >  > 1. mailto:[9]mohammed.hassan at jollamobile.com
> >  > 2. [10]http://agilesoftwaredevelopment.com/
> >  > 3. [11]http://twitter.com/AgileArtem
> >  > 4. [12]http://agilesoftwaredevelopment.com/
> >  > 5. [13]http://twitter.com/AgileArtem
> >  > 6. [14]http://agilesoftwaredevelopment.com/
> >  > 7. [15]http://twitter.com/AgileArtem
> >
> >  --
> >  Artem Marchenko
> >  [16]http://agilesoftwaredevelopment.com
> >  [17]http://twitter.com/AgileArtem
> >
> > References
> >
> >  1. mailto:mohammed.hassan at jollamobile.com
> >  2. mailto:mohammed.hassan at jollamobile.com
> >  3. http://agilesoftwaredevelopment.com/
> >  4. http://twitter.com/AgileArtem
> >  5. http://agilesoftwaredevelopment.com/
> >  6. http://twitter.com/AgileArtem
> >  7. http://agilesoftwaredevelopment.com/
> >  8. http://twitter.com/AgileArtem
> >  9. mailto:mohammed.hassan at jollamobile.com
> >  10. http://agilesoftwaredevelopment.com/
> >  11. http://twitter.com/AgileArtem
> >  12. http://agilesoftwaredevelopment.com/
> >  13. http://twitter.com/AgileArtem
> >  14. http://agilesoftwaredevelopment.com/
> >  15. http://twitter.com/AgileArtem
> >  16. http://agilesoftwaredevelopment.com/
> >  17. http://twitter.com/AgileArtem
>



-- 
Artem Marchenko
http://agilesoftwaredevelopment.com
http://twitter.com/AgileArtem
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