text: # coding: utf-8
  
  from __future__ import unicode_literals
  
  import base64
  
  from ..compat import (
      compat_urllib_parse_unquote,
      compat_urlparse,
  )
  from ..utils import determine_ext
  from .bokecc import BokeCCBaseIE
  
  
  class InfoQIE(BokeCCBaseIE):
      _VALID_URL = r'https?://(?:www\.)?infoq\.com/(?:[^/]+/)+(?P<id>[^/]+)'
  
      _TESTS = [{
          'url': 'http://www.infoq.com/presentations/A-Few-of-My-Favorite-Python-Things',
          'md5': 'b5ca0e0a8c1fed93b0e65e48e462f9a2',
          'info_dict': {
              'id': 'A-Few-of-My-Favorite-Python-Things',
              'ext': 'mp4',
              'description': 'Mike Pirnat presents some tips and tricks, standard libraries and third party packages that make programming in Python a richer experience.',
              'title': 'A Few of My Favorite [Python] Things',
          },
      }, {
          'url': 'http://www.infoq.com/fr/presentations/changez-avis-sur-javascript',
          'only_matching': True,
      }, {
          'url': 'http://www.infoq.com/cn/presentations/openstack-continued-delivery',
          'md5': '4918d0cca1497f2244572caf626687ef',
          'info_dict': {
              'id': 'openstack-continued-delivery',
              'title': 'OpenStack持续交付之路',
              'ext': 'flv',
              'description': 'md5:308d981fb28fa42f49f9568322c683ff',
          },
      }, {
          'url': 'https://www.infoq.com/presentations/Simple-Made-Easy',
          'md5': '0e34642d4d9ef44bf86f66f6399672db',
          'info_dict': {
              'id': 'Simple-Made-Easy',
              'title': 'Simple Made Easy',
              'ext': 'mp3',
              'description': 'md5:3e0e213a8bbd074796ef89ea35ada25b',
          },
          'params': {
              'format': 'bestaudio',
          },
      }]
  
      def _extract_rtmp_video(self, webpage):
          # The server URL is hardcoded
          video_url = 'rtmpe://video.infoq.com/cfx/st/'
  
          # Extract video URL
          encoded_id = self._search_regex(
              r"jsclassref\s*=\s*'([^']*)'", webpage, 'encoded id', default=None)
  
          real_id = compat_urllib_parse_unquote(base64.b64decode(encoded_id.encode('ascii')).decode('utf-8'))
          playpath = 'mp4:' + real_id
  
          return [{
              'format_id': 'rtmp_video',
              'url': video_url,
              'ext': determine_ext(playpath),
              'play_path': playpath,
          }]
  
      def _extract_cookies(self, webpage):
          policy = self._search_regex(r'InfoQConstants\.scp\s*=\s*\'([^\']+)\'', webpage, 'policy')
          signature = self._search_regex(r'InfoQConstants\.scs\s*=\s*\'([^\']+)\'', webpage, 'signature')
          key_pair_id = self._search_regex(r'InfoQConstants\.sck\s*=\s*\'([^\']+)\'', webpage, 'key-pair-id')
          return 'CloudFront-Policy=%s; CloudFront-Signature=%s; CloudFront-Key-Pair-Id=%s' % (
              policy, signature, key_pair_id)
  
      def _extract_http_video(self, webpage):
          http_video_url = self._search_regex(r'P\.s\s*=\s*\'([^\']+)\'', webpage, 'video URL')
          return [{
              'format_id': 'http_video',
              'url': http_video_url,
              'http_headers': {
                  'Cookie': self._extract_cookies(webpage)
              },
          }]
  
      def _extract_http_audio(self, webpage, video_id):
          fields = self._hidden_inputs(webpage)
          http_audio_url = fields.get('filename')
          if not http_audio_url:
              return []
  
          cookies_header = {'Cookie': self._extract_cookies(webpage)}
  
          # base URL is found in the Location header in the response returned by
          # GET https://www.infoq.com/mp3download.action?filename=... when logged in.
          http_audio_url = compat_urlparse.urljoin('http://res.infoq.com/downloads/mp3downloads/', http_audio_url)
  
          # audio file seem to be missing some times even if there is a download link
          # so probe URL to make sure
          if not self._is_valid_url(http_audio_url, video_id, headers=cookies_header):
              return []
  
          return [{
              'format_id': 'http_audio',
              'url': http_audio_url,
              'vcodec': 'none',
              'http_headers': cookies_header,
          }]
  
      def _real_extract(self, url):
          video_id = self._match_id(url)
          webpage = self._download_webpage(url, video_id)
  
          video_title = self._html_search_regex(r'<title>(.*?)</title>', webpage, 'title')
          video_description = self._html_search_meta('description', webpage, 'description')
  
          if '/cn/' in url:
              # for China videos, HTTP video URL exists but always fails with 403
              formats = self._extract_bokecc_formats(webpage, video_id)
          else:
              formats = (
                  self._extract_rtmp_video(webpage) +
                  self._extract_http_video(webpage) +
                  self._extract_http_audio(webpage, video_id))
  
          self._sort_formats(formats)
  
          return {
              'id': video_id,
              'title': video_title,
              'description': video_description,
              'formats': formats,
          }
  