Added support for gphoto2-cffi instead of piggyphoto to allow disabling the sensor while idle

README.md

@@ -19,7 +19,7 @@ The following is required for running this photobooth application. I used the ve
 * [Pillow](http://pillow.readthedocs.org) (2.8.1)
 * [gPhoto](http://gphoto.sourceforge.net/) (2.5.6 or later) or [OpenCV](http://opencv.org)
 * Optional: [RPi.GPIO](https://pypi.python.org/pypi/RPi.GPIO) (0.5.11)
-* Optional: [Piggyphoto](https://github.com/alexdu/piggyphoto)
+* Optional: [gphoto2-cffi](https://github.com/jbaiter/gphoto2-cffi) or [Piggyphoto](https://github.com/alexdu/piggyphoto)
 
 RPi.GPIO is necessary to use external buttons as a trigger but it works just fine without. Triggering is then only possible using touch screen / mouse or key 'c'.
 
@@ -115,7 +115,23 @@ A brief description on how to set-up a Raspberry Pi to use this photobooth softw
    ```
    and run `photobooth.py`
 
-8. Optional but highly recommended, as it improves performance significantly: Download the gPhoto2 Python-bindings [Piggyphoto](https://github.com/alexdu/piggyphoto) and put the folder `piggyphoto` into the Photobooth-directory.
+8. Optional but highly recommended, as it improves performance significantly: install some Python bindings for gPhoto2. For that, either [Piggyphoto](https://github.com/alexdu/piggyphoto) or [gphoto2-cffi](https://github.com/jbaiter/gphoto2-cffi) can be used. At the moment, Piggyphoto doesn't allow to disable the sensor while idle, so gphoto2-cffi is preferred.
+
+   8.1 Installing gphoto2-cffi:
+   Install [cffi](https://bitbucket.org/cffi/cffi)
+   ```
+   sudo apt-get install libffi6 libffi-dev python-cffi
+   ```
+   Download and install gphoto2-cffi for gPhoto2
+   ```
+   git clone https://github.com/jbaiter/gphoto2-cffi.git
+   cd gphoto2-cffi
+   python setup.py build
+   sudo python setup.py install
+   ```
+
+   8.2 Install Piggyphoto:
+   Download [Piggyphoto](https://github.com/alexdu/piggyphoto) and put the folder `piggyphoto` into the Photobooth-directory.
 
 9. Optionally make the software run automatically on startup. To do that, you must simply add a corresponding line in the autostart file of LXDE, which can be found at `~/.config/lxsession/LXDE-pi/autostart`. Assuming you cloned the Photobooth repository into `/home/pi/photobooth`, add the following line into the autostart-file:
    ```

camera.py

@@ -3,19 +3,33 @@
 
 import subprocess
 
+cv_enabled = False
+gphoto2cffi_enabled = False
+piggyphoto_enabled = False
+
 try:
     import cv2 as cv
     cv_enabled = True
     print('OpenCV available')
 except ImportError:
-    cv_enabled = False
+    pass
 
 try:
-    import piggyphoto
+    import gphoto2cffi as gp
-    piggyphoto_enabled = True
+    gpExcept = gp.errors.GPhoto2Error
-    print('Piggyphoto available')
+    gphoto2cffi_enabled = True
+    print('Gphoto2cffi available')
 except ImportError:
-    piggyphoto_enabled = False
+    pass
+
+if not gphoto2cffi_enabled:
+    try:
+        import piggyphoto as gp
+        gpExcept = gp.libgphoto2error
+        piggyphoto_enabled = True
+        print('Piggyphoto available')
+    except ImportError:
+        pass
 
 class CameraException(Exception):
     """Custom exception class to handle camera class errors"""
@@ -45,6 +59,9 @@ class Camera_cv:
         else:
             raise CameraException("OpenCV not available!")
 
+    def set_idle(self):
+        pass
+
 
 class Camera_gPhoto:
     """Camera class providing functionality to take pictures using gPhoto 2"""
@@ -53,14 +70,16 @@ class Camera_gPhoto:
         self.picture_size = picture_size
         # Print the capabilities of the connected camera
         try:
-            if piggyphoto_enabled:
+            if gphoto2cffi_enabled:
-                self.cap = piggyphoto.camera()
+                self.cap = gp.Camera()
+            elif piggyphoto_enabled:
+                self.cap = gp.camera()
                 print(self.cap.abilities)
             else:
                 print(self.call_gphoto("-a", "/dev/null"))
         except CameraException as e:
             print('Warning: Listing camera capabilities failed (' + e.message + ')')
-        except piggyphoto.libgphoto2error as e:
+        except gpExcept as e:
             print('Warning: Listing camera capabilities failed (' + e.message + ')')
 
     def call_gphoto(self, action, filename):
@@ -82,17 +101,33 @@ class Camera_gPhoto:
         return output
 
     def has_preview(self):
-        return piggyphoto_enabled
+        return gphoto2cffi_enabled or piggyphoto_enabled
 
     def take_preview(self, filename="/tmp/preview.jpg"):
-        if piggyphoto_enabled:
+        if gphoto2cffi_enabled:
+            self._save_picture(filename, self.cap.get_preview())
+        elif piggyphoto_enabled:
             self.cap.capture_preview(filename)	
         else:
             raise CameraException("No preview supported!")
 
     def take_picture(self, filename="/tmp/picture.jpg"):
-        if piggyphoto_enabled:
+        if gphoto2cffi_enabled:
+            self._save_picture(filename, self.cap.capture())
+        elif piggyphoto_enabled:
             self.cap.capture_image(filename)
         else:
             self.call_gphoto("--capture-image-and-download", filename)
         return filename
+
+    def _save_picture(self, filename, data):
+        f = open(filename, 'wb')
+        f.write(data)
+        f.close()
+
+    def set_idle(self):
+        if gphoto2cffi_enabled:
+            self.cap._get_config()['actions']['viewfinder'].set(False)
+        elif piggyphoto_enabled:
+            # This doesn't work...
+            self.cap.config.main.actions.viewfinder.value = 0

photobooth.py

@@ -139,6 +139,7 @@ class Photobooth:
                 self.gpio.set_output(self.lamp_channel, 1)
 
                 while True:
+                    self.camera.set_idle()
                     # Display default message
                     self.display.clear()
                     self.display.show_message("Hit the button!")