Re: Getting a hook from shell mode to do motion detection?

Well, I haven't had a lot of luck getting things from the
libgphoto2/examples dir running so I gave up.  Just recently I tried
copying sample-photobooth.c (and samples.h) into an empty dir and
compiling with a makefile that looks like

-------------
pb: sample-photobooth.c
        gcc -Wall -o pb -lgphoto2 sample-photobooth.c \
  -L/usr/local/bin/gphoto2-2.5.15/lib

# lib path is because I didn't want it to conflict with debs gphoto
# it's where libgphoto2.so.6.0.0  is
--------------

And I get errors like:
upstairs# make
gcc -Wall -o pb -lgphoto2 sample-photobooth.c \
  -L/usr/local/bin/gphoto2-2.5.15/lib
/usr/bin/ld: /tmp/ccBGh1Jj.o: undefined reference to symbol
'gp_log_add_func@@LIBGPHOTO2_5_0'
//usr/local/bin/gphoto2-2.5.15/lib/libgphoto2_port.so.12: error adding
symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
Makefile:2: recipe for target 'pb' failed
make: *** [pb] Error 1

I did an ldconfig on the path where the library is.  I was also
getting the "DSO missing from command line" error trying to build
preview.c.  I've never seen it on anything I wrote, trying to google
it wasn't very productive.

On 12/31/17, Marcus Meissner <[email protected]> wrote:
> Hi,
>
> If you want to do this all with one camera you might be better of writing
> a program using libgphoto2, either in C or Python.
>
> FWIW, I did something similar to Tomas btw.
>
> Setup:
>
> - Cheap Webcam
> - Canon EOS 1000D with AC adapter.
> - Laptop
>
> Then I ran the "motion" tool using the webcam.
>
> The "motion" tool has hooks where it can callout to shell scripts.
> I wrote a simple shell script that ran gphoto2 --capture-image-and-download
>
> and hooked it to the motion detection hook.
>
> It needed some checking that it does not run it twice (because
> if there is motion it would trigger faster than capturing)
> and it runs the disk full quite quickly with DSLR sized images.
>
> Ciao, Marcus
>
>
> On Sat, Dec 30, 2017 at 02:06:13PM -0500, Alan Corey wrote:
>> I've been thinking about this.  I plan to write in C, and between
>> system() and popen() and pipe() and etc there's probably a way to do
>> it.  From a console you type shell and give commands, then you can
>> type more commands.  But I'm not sure how a program would do that: as
>> a file descriptor or a pipe (or a socket) (dbus?)?  Gphoto as a
>> process stays running, you just need a programmatic way to communicate
>> with it.  The looping and branching wouldn't happen in Gphoto's shell,
>> that would be more like a low level server or driver.  I could of
>> course modify my copy of the source but I'd rather not do that.  I was
>> about to experiment a bit until I found my oldschool loadjpeg function
>> evidently doesn't work under Linux, I need to make a Turbo Jpeg
>> equivalent.  Or maybe I still need some dev file or header.  Wacky, it
>> doesn't know jpeg_CreateDecompress or what a size_t is?  I wrote it
>> under OpenBSD a couple years ago, it's been reasonably portable until
>> now.  Loading a straight uncompressed RGB binary would be optimum but
>> I need to decompress jpegs.  Don't know yet if I can send to stdout.
>>
>> I ran across motion last night but didn't bother to install it.  I
>> think it's strictly V4L so it's low quality just because the cameras
>> are.  I've got a 640x480 USB webcam that does V4L but I'd rather not
>> use it.  My motion detection scheme comes partly from a D-Link IP cam,
>> that also only does 640x480.  I'll probably be running this on a
>> Raspberry Pi, and I've got a few of those cameras, but I'd rather not
>> use them.
>>
>> The standard Gphoto --capture-preview or the shell equivalent gets me
>> a 320x240 jpeg which, if I decompress and compare in C, not something
>> awful like Python, should be fast enough.  I'd rather not use 2
>> cameras.  I'm from the Nikon camp, new to Canons for this project.
>> For $20 used I got a 7 MP camera that not only works with Gphoto but
>> also shoots RAW, most low-end Nikons won't do either.  I'm not
>> sticking my D5200 DSLR in a birdfeeder.
>>
>> Shell mode is good for this because there's only 1 start-up time, the
>> delay between pictures can be much lower than if you call Gphoto in a
>> loop to start from scratch each time.  1 frame per second might be
>> adequate but I'm aiming at 10.  CPU time on a Pi 3 comes cheap since
>> it runs on a watt or two.  So I don't need to compare 320x240 images
>> but if I can do it efficiently I can live with it.
>>
>> On 12/30/17, Tomas Alonso <[email protected]> wrote:
>> > El Viernes, 29 de diciembre de 2017 17:39:08 Alan Corey escribió:
>> >> I want to set up a wildlife camera, so I've read a few articles about
>> >> it.  I've been practicing with an old Canon PowerShot S70 and it seems
>> >> suitable.  What I'd like to try to do is use the preview images for
>> >> motion detection.  I need to mask out some areas to avoid false
>> >> activations from clouds passing over, that sort of stuff, and probably
>> >> some averaging to account for the sun rising and setting.
>> >>
>> >> For speed it seems advisable to work in Gphoto2's shell mode but I'm
>> >> trying to figure out a way to provide input from an external program.
>> >> I want to do capture-preview in a loop: get a preview, run my compare
>> >> program, get another preview.  If the compare sees something go into
>> >> another loop grabbing big images for some amount of time, then back to
>> >> previews.
>> >>
>> >> I did help in shell mode but I don't see anything listed that looks
>> >> like it would work, like being able to detect the presence of some
>> >> file I could use a a semaphore.  There aren't any branch (or loop)
>> >> instructions either.
>> >>
>> >>   Alan
>> >
>> > Hello Alan,
>> >
>> > For other needs related to security I'm also interested in doing
>> > something
>> > equivalent. I thought my first try would be
>> >
>> > http://www.chriswpage.com/2009/05/setup-an-advanced-webcam-security-system-with-ubuntu-8-04-and-motion/
>> >
>> > using the motion program under Linux. It allows to launch scripts when
>> > motion
>> > is detected, but you need a webcam for motion detection and a camera
>> > for
>> > good
>> > quality shots. That's (and the fact I own a Canon 40D) why I'm not sure
>> > at
>> > all
>> > about the webcam approach.
>> >
>> > I have high programming skills and experience with gphoto so to
>> > implement
>> > this
>> > myself will not be a problem. If you can't find a solution for your
>> > case
>> > just
>> > send me the exact gphoto commands you use for your camera to enter
>> > shell
>> > mode,
>> > take a preview, and take also a big image in auto mode or whatever you
>> > use
>> > (including the file names generated in your computer after executing
>> > those
>> > commands).
>> >
>> > Can't promise to do it for a given date but likely it will take few
>> > weeks.
>> >
>> > Regards,
>> > Tomas.
>> >
>> >
>> > ------------------------------------------------------------------------------
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>> >
>>
>>
>> --
>> -------------
>> No, I won't  call it "climate change", do you have a "reality problem"? -
>> AB1JX
>> Impeach  Impeach  Impeach  Impeach  Impeach  Impeach  Impeach  Impeach
>>
>> ------------------------------------------------------------------------------
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>


-- 
-------------
No, I won't  call it "climate change", do you have a "reality problem"? - AB1JX
Impeach  Impeach  Impeach  Impeach  Impeach  Impeach  Impeach  Impeach

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