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

Mohammed Hassan mohammed.hassan at jollamobile.com
Sat Nov 16 16:56:00 UTC 2013 

Great job Artem

I tried it and it works (it pulses as expected).

If I point camera to a lamp then the led lights up for a long time.
If I direct it away from the lamp then the pulses are shorter.

I personally am not sure about the Qt API but from gstreamer output, I see that
you must call unlock().

I will try to test it tomorrow morning and see if it will still fire or not.

I guess we also need to tweak the timer for locking and unlocking but I don't
really have any suggestions.

Cheers,

On Sat, Nov 16, 2013 at 06:22:32PM +0200, Artem Marchenko wrote:
>  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 - [1]http://bit.ly/videofla109
>  Or here's full source code
>  - [2]https://github.com/amarchen/video-flash-trial/tree/v0.1-9/
>  Cheers,
>  Artem.
> 
>  On Sat, Nov 16, 2013 at 6:05 PM, Mohammed Hassan
>  <[3]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][4]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][5]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][6]http://agilesoftwaredevelopment.com
>  > > > [2][3][4][7]http://twitter.com/AgileArtem
>  > > >
>  > > > References
>  > > >
>  > > > 1. [4][5][8]http://agilesoftwaredevelopment.com/
>  > > > 2. [5][6][9]http://twitter.com/AgileArtem
>  > >
>  > > --
>  > > Artem Marchenko
>  > > [6][7][10]http://agilesoftwaredevelopment.com
>  > > [7][8][11]http://twitter.com/AgileArtem
>  > >
>  > > References
>  > >
>  > > 1. mailto:[9][12]mohammed.hassan at jollamobile.com
>  > > 2. [10][13]http://agilesoftwaredevelopment.com/
>  > > 3. [11][14]http://twitter.com/AgileArtem
>  > > 4. [12][15]http://agilesoftwaredevelopment.com/
>  > > 5. [13][16]http://twitter.com/AgileArtem
>  > > 6. [14][17]http://agilesoftwaredevelopment.com/
>  > > 7. [15][18]http://twitter.com/AgileArtem
>  >
>  > --
>  > Artem Marchenko
>  > [16][19]http://agilesoftwaredevelopment.com
>  > [17][20]http://twitter.com/AgileArtem
>  >
>  > References
>  >
>  > 1. mailto:[21]mohammed.hassan at jollamobile.com
>  > 2. mailto:[22]mohammed.hassan at jollamobile.com
>  > 3. [23]http://agilesoftwaredevelopment.com/
>  > 4. [24]http://twitter.com/AgileArtem
>  > 5. [25]http://agilesoftwaredevelopment.com/
>  > 6. [26]http://twitter.com/AgileArtem
>  > 7. [27]http://agilesoftwaredevelopment.com/
>  > 8. [28]http://twitter.com/AgileArtem
>  > 9. mailto:[29]mohammed.hassan at jollamobile.com
>  > 10. [30]http://agilesoftwaredevelopment.com/
>  > 11. [31]http://twitter.com/AgileArtem
>  > 12. [32]http://agilesoftwaredevelopment.com/
>  > 13. [33]http://twitter.com/AgileArtem
>  > 14. [34]http://agilesoftwaredevelopment.com/
>  > 15. [35]http://twitter.com/AgileArtem
>  > 16. [36]http://agilesoftwaredevelopment.com/
>  > 17. [37]http://twitter.com/AgileArtem
> 
>  --
>  Artem Marchenko
>  [38]http://agilesoftwaredevelopment.com
>  [39]http://twitter.com/AgileArtem
> 
> References
> 
>  1. http://bit.ly/videofla109
>  2. https://github.com/amarchen/video-flash-trial/tree/v0.1-9/
>  3. mailto:mohammed.hassan at jollamobile.com
>  4. mailto:mohammed.hassan at jollamobile.com
>  5. mailto:mohammed.hassan at jollamobile.com
>  6. http://agilesoftwaredevelopment.com/
>  7. http://twitter.com/AgileArtem
>  8. http://agilesoftwaredevelopment.com/
>  9. http://twitter.com/AgileArtem
>  10. http://agilesoftwaredevelopment.com/
>  11. http://twitter.com/AgileArtem
>  12. mailto:mohammed.hassan at jollamobile.com
>  13. http://agilesoftwaredevelopment.com/
>  14. http://twitter.com/AgileArtem
>  15. http://agilesoftwaredevelopment.com/
>  16. http://twitter.com/AgileArtem
>  17. http://agilesoftwaredevelopment.com/
>  18. http://twitter.com/AgileArtem
>  19. http://agilesoftwaredevelopment.com/
>  20. http://twitter.com/AgileArtem
>  21. mailto:mohammed.hassan at jollamobile.com
>  22. mailto:mohammed.hassan at jollamobile.com
>  23. http://agilesoftwaredevelopment.com/
>  24. http://twitter.com/AgileArtem
>  25. http://agilesoftwaredevelopment.com/
>  26. http://twitter.com/AgileArtem
>  27. http://agilesoftwaredevelopment.com/
>  28. http://twitter.com/AgileArtem
>  29. mailto:mohammed.hassan at jollamobile.com
>  30. http://agilesoftwaredevelopment.com/
>  31. http://twitter.com/AgileArtem
>  32. http://agilesoftwaredevelopment.com/
>  33. http://twitter.com/AgileArtem
>  34. http://agilesoftwaredevelopment.com/
>  35. http://twitter.com/AgileArtem
>  36. http://agilesoftwaredevelopment.com/
>  37. http://twitter.com/AgileArtem
>  38. http://agilesoftwaredevelopment.com/
>  39. http://twitter.com/AgileArtem

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