[gametrailers] Fix extraction (fixes #7722)

They have stopped using the MTV system.

youtube_dl/extractor/gametrailers.py

@@ -1,19 +1,62 @@
 from __future__ import unicode_literals
 
-from .mtv import MTVServicesInfoExtractor
+from .common import InfoExtractor
+from ..utils import (
+    int_or_none,
+    parse_age_limit,
+    url_basename,
+)
 
 
-class GametrailersIE(MTVServicesInfoExtractor):
-    _VALID_URL = r'http://www\.gametrailers\.com/(?P<type>videos|reviews|full-episodes)/(?P<id>.*?)/(?P<title>.*)'
+class GametrailersIE(InfoExtractor):
+    _VALID_URL = r'http://www\.gametrailers\.com/videos/view/[^/]+/(?P<id>.+)'
+
     _TEST = {
-        'url': 'http://www.gametrailers.com/videos/zbvr8i/mirror-s-edge-2-e3-2013--debut-trailer',
-        'md5': '4c8e67681a0ea7ec241e8c09b3ea8cf7',
+        'url': 'http://www.gametrailers.com/videos/view/gametrailers-com/116437-Just-Cause-3-Review',
+        'md5': 'f28c4efa0bdfaf9b760f6507955b6a6a',
         'info_dict': {
-            'id': '70e9a5d7-cf25-4a10-9104-6f3e7342ae0d',
+            'id': '2983958',
             'ext': 'mp4',
-            'title': 'E3 2013: Debut Trailer',
-            'description': 'Faith is back!  Check out the World Premiere trailer for Mirror\'s Edge 2 straight from the EA Press Conference at E3 2013!',
+            'display_id': '116437-Just-Cause-3-Review',
+            'title': 'Just Cause 3 - Review',
+            'description': 'It\'s a lot of fun to shoot at things and then watch them explode in Just Cause 3, but should there be more to the experience than that?',
         },
     }
 
-    _FEED_URL = 'http://www.gametrailers.com/feeds/mrss'
+    def _real_extract(self, url):
+        display_id = self._match_id(url)
+        webpage = self._download_webpage(url, display_id)
+        title = self._html_search_regex(
+            r'<title>(.+?)\|', webpage, 'title').strip()
+        embed_url = self._proto_relative_url(
+            self._search_regex(
+                r'src=\'(//embed.gametrailers.com/embed/[^\']+)\'', webpage,
+                'embed url'),
+            scheme='http:')
+        video_id = url_basename(embed_url)
+        embed_page = self._download_webpage(embed_url, video_id)
+        embed_vars_json = self._search_regex(
+            r'(?s)var embedVars = (\{.*?\})\s*</script>', embed_page,
+            'embed vars')
+        info = self._parse_json(embed_vars_json, video_id)
+
+        formats = []
+        for media in info['media']:
+            if media['mediaPurpose'] == 'play':
+                formats.append({
+                    'url': media['uri'],
+                    'height': media['height'],
+                    'width:': media['width'],
+                })
+        self._sort_formats(formats)
+
+        return {
+            'id': video_id,
+            'display_id': display_id,
+            'title': title,
+            'formats': formats,
+            'thumbnail': info.get('thumbUri'),
+            'description': self._og_search_description(webpage),
+            'duration': int_or_none(info.get('videoLengthInSeconds')),
+            'age_limit': parse_age_limit(info.get('audienceRating')),
+        }