[ADD] Library to embed youtube and vimeo videos in a clean way

Coming from https://gist.github.com/dbrgn/2922648

_extensions/embedded_video.py

@@ -0,0 +1,66 @@
+# -*- coding: utf-8 -*-
+"""
+    ReST directive for embedding Youtube and Vimeo videos.
+    There are two directives added: ``youtube`` and ``vimeo``. The only
+    argument is the video id of the video to include.
+    Both directives have three optional arguments: ``height``, ``width``
+    and ``align``. Default height is 281 and default width is 500.
+    Example::
+        .. youtube:: anwy2MPT5RE
+            :height: 315
+            :width: 560
+            :align: left
+    :copyright: (c) 2012 by Danilo Bargen.
+    :license: BSD 3-clause
+"""
+from __future__ import absolute_import
+from docutils import nodes
+from docutils.parsers.rst import Directive, directives
+
+
+def align(argument):
+    """Conversion function for the "align" option."""
+    return directives.choice(argument, ('left', 'center', 'right'))
+
+
+class IframeVideo(Directive):
+    has_content = False
+    required_arguments = 1
+    optional_arguments = 0
+    final_argument_whitespace = False
+    option_spec = {
+        'height': directives.nonnegative_int,
+        'width': directives.nonnegative_int,
+        'align': align,
+    }
+    default_width = 500
+    default_height = 281
+
+    def run(self):
+        self.options['video_id'] = directives.uri(self.arguments[0])
+        if not self.options.get('width'):
+            self.options['width'] = self.default_width
+        if not self.options.get('height'):
+            self.options['height'] = self.default_height
+        if not self.options.get('align'):
+            self.options['align'] = 'left'
+        return [nodes.raw('', self.html % self.options, format='html')]
+
+
+class Youtube(IframeVideo):
+    html = '<iframe src="http://www.youtube.com/embed/%(video_id)s" \
+    width="%(width)u" height="%(height)u" frameborder="0" \
+    webkitAllowFullScreen mozallowfullscreen allowfullscreen \
+    class="align-%(align)s"></iframe>'
+
+
+class Vimeo(IframeVideo):
+    html = '<iframe src="http://player.vimeo.com/video/%(video_id)s" \
+    width="%(width)u" height="%(height)u" frameborder="0" \
+    webkitAllowFullScreen mozallowfullscreen allowFullScreen \
+    class="align-%(align)s"></iframe>'
+
+
+def setup(builder):
+    directives.register_directive('youtube', Youtube)
+    directives.register_directive('vimeo', Vimeo)

conf.py

@@ -34,6 +34,7 @@ extensions = [
     'html_domain',
     'demo_link',
     'github_link',
+    'embedded_video',
 ]
 
 # Add any paths that contain templates here, relative to this directory.