Linux: get rid of libmss, insanely fast using only ctypes :)

BoboTiG · BoboTiG · commit 153f0620b7a6 · 2016-10-06T20:28:41.000+02:00
diff --git a/CHANGELOG b/CHANGELOG
@@ -5,8 +5,8 @@ History:
 dev
       - change license to MIT
       - add documentation (fix #10)
-      - Linux: MSS library optional at installation
-      - Linux: optimization of get_pixels_slow()
+      - Linux: remove MSS library
+      - Linux: insanely fast using only ctypes
 
 2.0.0   2016/06/04
       - split the module into several files
diff --git a/docs/source/api.rst b/docs/source/api.rst
@@ -25,6 +25,14 @@ Methods
 
 .. class:: MSSBase
 
+    .. method:: bgra_to_rgb(raw) -> bytes
+
+        :param mixed raw: raw data containing BGRA values.
+
+        It converts pixels values from BGRA to RGB.
+        This is the method called to populate :attr:`image` into :attr:`get_pixels`.
+
+
     .. method:: enum_display_monitors(force=False) -> list(dict)
 
         :param bool force: force rescan of monitors informations.
@@ -53,7 +61,7 @@ Methods
         :param dict monitor: monitor's informations generated by :attr:`enum_display_monitors()`.
         :exception NotImplementedError: Subclasses need to implement this.
 
-        Retrieve screen pixels for a given monitor. 
+        Retrieve screen pixels for a given monitor.
         This method has to define :attr:`width` and :attr:`height`.
         It stocks pixels data into :attr:`image` (RGB) and returns it.
 
diff --git a/docs/source/installation.rst b/docs/source/installation.rst
@@ -19,25 +19,6 @@ Alternatively, you can get a copy of the module from GitHub::
     cd python-mss
 
 
-Optional dependency
--------------------
-
-The MSS library is already compiled for 32 and 64 bits architectures but you can build for your system::
-
-    cd mss/linux
-    sh build.sh
-    cd ../..
-
-The resulting file will be located into ``mss/linux/$ARCH/libmss.so`` and will be used for the next step.
-
-
-Installation
-------------
-
-Install them module::
+And then::
 
     sudo python setup.py install
-
-You can avoid the MSS library dependency by specifying the `--no-dependency` argument::
-
-    sudo python setup.py install --no-dependency
diff --git a/mss/__init__.py b/mss/__init__.py
@@ -15,7 +15,7 @@
 from .exception import ScreenshotError
 from .factory import mss
 
-__version__ = '2.0.5'
+__version__ = '2.0.6'
 __author__ = "Mickaël 'Tiger-222' Schoentgen"
 __copyright__ = '''
     Copyright (c) 2013-2016, Mickaël 'Tiger-222' Schoentgen
diff --git a/mss/base.py b/mss/base.py
@@ -27,6 +27,13 @@ def __enter__(self):
     def __exit__(self, exc_type, exc_value, traceback):
         ''' For the cool call `with MSS() as mss:`. '''
 
+    def bgra_to_rgb(self, raw):
+        ''' Converts pixels values from BGRA to RGB. '''
+
+        image = bytearray(self.height * self.width * 3)
+        image[0::3], image[1::3], image[2::3] = raw[2::4], raw[1::4], raw[0::4]
+        return bytes(image)
+
     def enum_display_monitors(self, force=False):
         ''' Get positions of one or more monitors.
             If the monitor has rotation, you have to deal with it
diff --git a/mss/darwin.py b/mss/darwin.py
@@ -158,11 +158,5 @@ def get_pixels(self, monitor):
         buf_len = self.height * self.width * 4  # or CFDataGetLength()
         data = cast(data_ref, POINTER(c_ubyte * buf_len))
         self.core.CGDataProviderRelease(prov)
-
-        # Replace pixels values: BGRA to RGB.
-        image_data = bytearray(data.contents)
-        image = bytearray(self.height * self.width * 3)
-        image[0::3], image[1::3], image[2::3] = \
-            image_data[2::4], image_data[1::4], image_data[0::4]
-        self.image = bytes(image)
+        self.image = self.bgra_to_rgb(bytearray(data.contents))
         return self.image
diff --git a/mss/linux.py b/mss/linux.py
@@ -5,12 +5,10 @@
 '''
 
 from ctypes import (
-    POINTER, Structure, byref, c_char_p, c_int, c_int32, c_long, c_uint,
-    c_uint32, c_ulong, c_ushort, c_void_p, cast, cdll, create_string_buffer)
+    POINTER, Structure, byref, c_char_p, c_int, c_int32, c_long, c_ubyte,
+    c_uint, c_uint32, c_ulong, c_ushort, c_void_p, cast, cdll)
 from ctypes.util import find_library
 from os import environ
-from os.path import abspath, dirname, isfile, realpath
-from struct import pack
 from sys import maxsize, version
 
 from .base import MSSBase
@@ -85,11 +83,7 @@ class MSS(MSSBase):
         It uses intensively the Xlib and Xrandr extension.
     '''
 
-    # pylint: disable=too-many-instance-attributes
-
     display = None
-    use_mss = False
-    mss = None
     xlib = None
     xrandr = None
     display = None
@@ -127,15 +121,6 @@ def __init__(self, display=None):
             raise ScreenshotError('No Xrandr extension found.')
         self.xrandr = cdll.LoadLibrary(xrandr)
 
-        # libmss = find_library('mss')
-        libmss = '{0}/linux/{1}/libmss.so'.format(
-            dirname(realpath(abspath(__file__))), arch())
-        if isfile(libmss):
-            self.mss = cdll.LoadLibrary(libmss)
-            self.use_mss = True
-        # else:
-        #    print('No MSS library found. Using slow native function.')
-
         self._set_argtypes()
         self._set_restypes()
 
@@ -148,13 +133,7 @@ def __init__(self, display=None):
         self.root = self.xlib.XDefaultRootWindow(self.display, screen)
 
     def _set_argtypes(self):
-        ''' Functions arguments.
-
-            Curiously, if we set up XGetPixel arguments type,
-            the entire process takes twice more time.
-            So, no need to waste this precious time :)
-            Note: this issue does not occur when using libmss.
-        '''
+        ''' Functions arguments. '''
 
         self.xlib.XOpenDisplay.argtypes = [c_char_p]
         self.xlib.XDefaultScreen.argtypes = [POINTER(Display)]
@@ -166,7 +145,6 @@ def _set_argtypes(self):
         self.xlib.XGetImage.argtypes = [POINTER(Display), POINTER(Display),
                                         c_int, c_int, c_uint, c_uint, c_ulong,
                                         c_int]
-        # self.xlib.XGetPixel.argtypes = [POINTER(XImage), c_int, c_int]
         self.xlib.XDestroyImage.argtypes = [POINTER(XImage)]
         self.xlib.XCloseDisplay.argtypes = [POINTER(Display)]
         self.xrandr.XRRGetScreenResources.argtypes = [POINTER(Display),
@@ -177,17 +155,9 @@ def _set_argtypes(self):
         self.xrandr.XRRFreeScreenResources.argtypes = \
             [POINTER(XRRScreenResources)]
         self.xrandr.XRRFreeCrtcInfo.argtypes = [POINTER(XRRCrtcInfo)]
-        if self.use_mss:
-            self.mss.GetXImagePixels.argtypes = [POINTER(XImage), c_void_p]
 
     def _set_restypes(self):
-        ''' Functions return type.
-
-            Curiously, if we set up XGetPixel return type,
-            the entire process takes a little more time.
-            So, no need to waste this precious time :)
-            Note: this issue does not occur when using libmss.
-        '''
+        ''' Functions return type. '''
 
         def validate(value):
             ''' Validate the returned value of xrandr.XRRGetScreenResources().
@@ -207,16 +177,13 @@ def validate(value):
         self.xlib.XGetWindowAttributes.restype = c_int
         self.xlib.XAllPlanes.restype = c_ulong
         self.xlib.XGetImage.restype = POINTER(XImage)
-        # self.xlib.XGetPixel.restype = c_ulong
         self.xlib.XDestroyImage.restype = c_void_p
         self.xlib.XCloseDisplay.restype = c_void_p
         self.xlib.XDefaultRootWindow.restype = POINTER(XWindowAttributes)
         self.xrandr.XRRGetScreenResources.restype = validate
         self.xrandr.XRRGetCrtcInfo.restype = POINTER(XRRCrtcInfo)
         self.xrandr.XRRFreeScreenResources.restype = c_void_p
         self.xrandr.XRRFreeCrtcInfo.restype = c_void_p
-        if self.use_mss:
-            self.mss.GetXImagePixels.restype = c_int
 
     def enum_display_monitors(self, force=False):
         ''' Get positions of monitors (see parent class). '''
@@ -277,52 +244,10 @@ def get_pixels(self, monitor):
             err = err.strip(', ')
             raise ScreenshotError(err)
 
-        if not self.use_mss:
-            self.get_pixels_slow(ximage)
-        else:
-            image = create_string_buffer(self.height * self.width * 3)
-            ret = self.mss.GetXImagePixels(ximage, image)
-            if not ret:
-                self.xlib.XDestroyImage(ximage)
-                err = 'libmss.GetXImagePixels() failed (retcode={0}).'
-                raise ScreenshotError(err.format(ret))
-            self.image = bytes(bytearray(image))
-        self.xlib.XDestroyImage(ximage)
-        return self.image
-
-    def get_pixels_slow(self, ximage):
-        ''' Retrieve all pixels from a monitor. Pixels have to be RGB.
-
-            (!) This version is damn slow, but if you consider that ~1 second
-            for a screenshot of decent monitor is not too long, you can
-            continue. There should be few things to tweak here to gain speed.
-        '''
-
-        # @TODO: this part takes most of the time. Need a better solution.
-        def pix(pixel, _resultats={}, p__=pack):
-            ''' Apply shifts to a pixel to get the RGB values.
-                This method uses of memoization.
-            '''
-
-            # pylint: disable=dangerous-default-value
-
-            try:
-                return _resultats[pixel]
-            except KeyError:
-                _resultats[pixel] = p__('<B', (pixel & rmask) >> 16) + \
-                    p__('<B', (pixel & gmask) >> 8) + \
-                    p__('<B', pixel & bmask)
-                return _resultats[pixel]
-
-        self.width = ximage.contents.width
-        self.height = ximage.contents.height
-        rmask = ximage.contents.red_mask
-        bmask = ximage.contents.blue_mask
-        gmask = ximage.contents.green_mask
-        xgetpixel = self.xlib.XGetPixel
-        pixels = [pix(xgetpixel(ximage, x, y))
-                  for y in range(self.height) for x in range(self.width)]
-        self.image = b''.join(pixels)
+        # Replace pixels values: BGRA to RGB.
+        buf_len = self.height * self.width * 4
+        data = cast(ximage.contents.data, POINTER(c_ubyte * buf_len))
+        self.image = self.bgra_to_rgb(bytearray(data.contents))
         return self.image
 
 
diff --git a/mss/linux/32/libmss.so b/mss/linux/32/libmss.so
diff --git a/mss/linux/64/libmss.so b/mss/linux/64/libmss.so
diff --git a/mss/linux/build.sh b/mss/linux/build.sh
diff --git a/mss/linux/mss.c b/mss/linux/mss.c
diff --git a/mss/windows.py b/mss/windows.py
@@ -103,7 +103,7 @@ def get_pixels(self, monitor):
 
             [2] bmi.bmiHeader.biBitCount = 32
                 image_data = create_string_buffer(height * width * 4)
-                # and later, the BGRX to RGB conversion
+                # and later, the BGRA to RGB conversion
 
             We grab the image in RGBX mode, so that each word is 32bit
             and we have no striding, then we transform to RGB.
@@ -159,11 +159,8 @@ def get_pixels(self, monitor):
             if bmp:
                 windll.gdi32.DeleteObject(bmp)
 
-        # Replace pixels values: BGRX to RGB. See [2].
-        image = bytearray(self.height * self.width * 3)
-        image[0::3], image[1::3], image[2::3] = \
-            image_data[2::4], image_data[1::4], image_data[0::4]
-        self.image = bytes(image)
+        # Replace pixels values: BGRA to RGB. See [2].
+        self.image = self.bgra_to_rgb(image_data)
         return self.image
 
 
diff --git a/setup.py b/setup.py
@@ -1,25 +1,11 @@
 #!/usr/bin/env python
 # coding: utf-8
 
-from platform import system
 from setuptools import setup
-from sys import argv, maxsize
 
 from mss import __version__
 
 
-# Optional libMSS to boost screen shots on GNU/Linux
-package_data = {}
-if '--no-dependency' in argv:
-    # Fix for "error: option --no-dependency not recognized"
-    argv.remove('--no-dependency')
-elif 'sdist' in argv:
-    package_data['mss'] = ['linux/build.sh', 'linux/mss.c',
-                           'linux/32/libmss.so', 'linux/64/libmss.so']
-elif system().lower() == 'linux':
-    arch = 64 if maxsize > 2 ** 32 else 32
-    package_data['mss'] = ['linux/{0}/libmss.so'.format(arch)]
-
 classifiers = [
     'Development Status :: 5 - Production/Stable',
     'Environment :: MacOS X',
@@ -81,13 +67,13 @@
     'maintainer': 'Tiger-222',
     'maintainer_email': 'contact@tiger-222.fr',
     'url': 'https://github.com/BoboTiG/python-mss',
-    'description': 'An ultra fast cross-platform multiple screenshots module in pure python using ctypes.',
+    'description': ('An ultra fast cross-platform multiple screenshots module '
+                    'in pure python using ctypes.'),
     'long_description': open('README.rst').read(),
     'classifiers': classifiers,
     'platforms': ['Darwin', 'Linux', 'Windows'],
-    'license': 'MIT',
     'packages': ['mss'],
-    'package_data': package_data
+    'license': 'MIT'
 }
 
 setup(**config)
