diff --git a/youtube_dl/extractor/limelight.py b/youtube_dl/extractor/limelight.py
index 5d2c3e2567..0d7abbaa84 100644
--- a/youtube_dl/extractor/limelight.py
+++ b/youtube_dl/extractor/limelight.py
@@ -37,11 +37,12 @@ def _extract_info(self, streams, mobile_urls, properties):
 
         for stream in streams:
             stream_url = stream.get('url')
-            if not stream_url:
+            if not stream_url or stream.get('previewStream') or stream.get('drmProtected'):
                 continue
-            if '.f4m' in stream_url:
+            ext = determine_ext(stream_url)
+            if ext == 'f4m':
                 formats.extend(self._extract_f4m_formats(
-                    stream_url, video_id, fatal=False))
+                    stream_url, video_id, f4m_id='hds', fatal=False))
             else:
                 fmt = {
                     'url': stream_url,
@@ -50,7 +51,7 @@ def _extract_info(self, streams, mobile_urls, properties):
                     'fps': float_or_none(stream.get('videoFrameRate')),
                     'width': int_or_none(stream.get('videoWidthInPixels')),
                     'height': int_or_none(stream.get('videoHeightInPixels')),
-                    'ext': determine_ext(stream_url)
+                    'ext': ext,
                 }
                 rtmp = re.search(r'^(?P<url>rtmpe?://[^/]+/(?P<app>.+))/(?P<playpath>mp4:.+)$', stream_url)
                 if rtmp:
@@ -68,18 +69,23 @@ def _extract_info(self, streams, mobile_urls, properties):
 
         for mobile_url in mobile_urls:
             media_url = mobile_url.get('mobileUrl')
-            if not media_url:
-                continue
             format_id = mobile_url.get('targetMediaPlatform')
-            if determine_ext(media_url) == 'm3u8':
+            if not media_url or format_id == 'Widevine':
+                continue
+            ext = determine_ext(media_url)
+            if ext == 'm3u8':
                 formats.extend(self._extract_m3u8_formats(
                     media_url, video_id, 'mp4', 'm3u8_native',
                     m3u8_id=format_id, fatal=False))
+            elif ext == 'f4m':
+                formats.extend(self._extract_f4m_formats(
+                    stream_url, video_id, f4m_id=format_id, fatal=False))
             else:
                 formats.append({
                     'url': media_url,
                     'format_id': format_id,
                     'preference': -1,
+                    'ext': ext,
                 })
 
         self._sort_formats(formats)
@@ -145,7 +151,7 @@ class LimelightMediaIE(LimelightBaseIE):
         'url': 'http://link.videoplatform.limelight.com/media/?mediaId=3ffd040b522b4485b6d84effc750cd86',
         'info_dict': {
             'id': '3ffd040b522b4485b6d84effc750cd86',
-            'ext': 'flv',
+            'ext': 'mp4',
             'title': 'HaP and the HB Prince Trailer',
             'description': 'md5:8005b944181778e313d95c1237ddb640',
             'thumbnail': 're:^https?://.*\.jpeg$',
@@ -154,7 +160,7 @@ class LimelightMediaIE(LimelightBaseIE):
             'upload_date': '20090604',
         },
         'params': {
-            # rtmp download
+            # m3u8 download
             'skip_download': True,
         },
     }, {
@@ -164,7 +170,6 @@ class LimelightMediaIE(LimelightBaseIE):
             'id': 'a3e00274d4564ec4a9b29b9466432335',
             'ext': 'flv',
             'title': '3Play Media Overview Video',
-            'description': '',
             'thumbnail': 're:^https?://.*\.jpeg$',
             'duration': 78.101,
             'timestamp': 1338929955,
@@ -172,7 +177,7 @@ class LimelightMediaIE(LimelightBaseIE):
             'subtitles': 'mincount:9',
         },
         'params': {
-            # rtmp download
+            # m3u8 download
             'skip_download': True,
         },
     }, {