diff --git a/youtube_dl/extractor/redtube.py b/youtube_dl/extractor/redtube.py
index a1ca791ca..0245ce2fa 100644
--- a/youtube_dl/extractor/redtube.py
+++ b/youtube_dl/extractor/redtube.py
@@ -1,33 +1,49 @@
+# coding: utf-8
 from __future__ import unicode_literals
 
 import re
 
 from .common import InfoExtractor
+from ..compat import compat_str
 from ..utils import (
     determine_ext,
     ExtractorError,
     int_or_none,
+    join_nonempty,
     merge_dicts,
     str_to_int,
+    T,
+    traverse_obj,
     unified_strdate,
     url_or_none,
+    urljoin,
 )
 
 
 class RedTubeIE(InfoExtractor):
     _VALID_URL = r'https?://(?:(?:\w+\.)?redtube\.com/|embed\.redtube\.com/\?.*?\bid=)(?P<id>[0-9]+)'
+    _EMBED_REGEX = [r'<iframe[^>]+?src=["\'](?P<url>(?:https?:)?//embed\.redtube\.com/\?.*?\bid=\d+)']
     _TESTS = [{
-        'url': 'http://www.redtube.com/66418',
-        'md5': 'fc08071233725f26b8f014dba9590005',
+        'url': 'https://www.redtube.com/38864951',
+        'md5': 'd7de9cb32e8adb3f6379f1a30f655fae',
         'info_dict': {
-            'id': '66418',
+            'id': '38864951',
             'ext': 'mp4',
-            'title': 'Sucked on a toilet',
-            'upload_date': '20110811',
-            'duration': 596,
+            'title': 'Public Sex on the Balcony in Freezing Paris! Amateur Couple LeoLulu',
+            'description': 'Watch video Public Sex on the Balcony in Freezing Paris! Amateur Couple LeoLulu on Redtube, home of free Blowjob porn videos and Blonde sex movies online. Video length: (10:46) - Uploaded by leolulu - Verified User - Starring Pornstar: LeoLulu',
+            'upload_date': '20210111',
+            'timestamp': 1610343109,
+            'duration': 646,
             'view_count': int,
             'age_limit': 18,
-        }
+            'thumbnail': r're:https://\wi-ph\.rdtcdn\.com/videos/.+/.+\.jpg',
+        },
+        'expected_warnings': [
+            'Failed to download m3u8 information: HTTP Error 404',
+        ],
+        'params': {
+            'format': '[format_id !^= hls]',
+        },
     }, {
         'url': 'http://embed.redtube.com/?bgcolor=000000&id=1443286',
         'only_matching': True,
@@ -36,11 +52,11 @@ class RedTubeIE(InfoExtractor):
         'only_matching': True,
     }]
 
-    @staticmethod
-    def _extract_urls(webpage):
-        return re.findall(
-            r'<iframe[^>]+?src=["\'](?P<url>(?:https?:)?//embed\.redtube\.com/\?.*?\bid=\d+)',
-            webpage)
+    @classmethod
+    def _extract_urls(cls, webpage):
+        for embed_re in cls._EMBED_REGEX:
+            for from_ in re.findall(embed_re, webpage):
+                yield from_
 
     def _real_extract(self, url):
         video_id = self._match_id(url)
@@ -71,40 +87,53 @@ class RedTubeIE(InfoExtractor):
             self._search_regex(
                 r'sources\s*:\s*({.+?})', webpage, 'source', default='{}'),
             video_id, fatal=False)
-        if sources and isinstance(sources, dict):
-            for format_id, format_url in sources.items():
-                if format_url:
-                    formats.append({
-                        'url': format_url,
-                        'format_id': format_id,
-                        'height': int_or_none(format_id),
-                    })
-        medias = self._parse_json(
-            self._search_regex(
-                r'mediaDefinition["\']?\s*:\s*(\[.+?}\s*\])', webpage,
-                'media definitions', default='{}'),
-            video_id, fatal=False)
-        if medias and isinstance(medias, list):
-            for media in medias:
-                format_url = url_or_none(media.get('videoUrl'))
+
+        def full_url(u):
+            return urljoin(url, u)
+
+        for fmt in traverse_obj(sources, (T(dict.items), {
+                'url': (1, T(full_url)),
+                'format_id': (2, T(compat_str)),
+                'height': (2, T(int_or_none)), })):
+            if 'url' in fmt:
+                formats.append(fmt)
+
+        medias = self._search_regex(
+            r'''mediaDefinitions?["']?\s*:\s*(\[[\s\S]+?}\s*\])''', webpage,
+            'media definitions', default='{}')
+        medias = self._parse_json(medias, video_id, fatal=False)
+        for fmt in traverse_obj(medias, (Ellipsis, T(dict))):
+            format_url = full_url(fmt.get('videoUrl'))
+            if not format_url:
+                continue
+            more_media = None
+            if fmt['format'] == 'hls' or (fmt['format'] == 'mp4' and not fmt.get('quality')):
+                more_media = self._download_json(format_url, video_id, fatal=False)
+            if more_media is None:
+                more_media = [fmt]
+            for fmt in traverse_obj(more_media, (Ellipsis, {
+                    'url': ('videoUrl', T(full_url)),
+                    'ext': ('format', T(compat_str)),
+                    'format_id': ('quality', T(compat_str)), })):
+                format_url = fmt.get('url')
                 if not format_url:
                     continue
-                if media.get('format') == 'hls' or determine_ext(format_url) == 'm3u8':
+                if fmt.get('ext') == 'hls' or determine_ext(format_url) == 'm3u8':
                     formats.extend(self._extract_m3u8_formats(
                         format_url, video_id, 'mp4',
                         entry_protocol='m3u8_native', m3u8_id='hls',
                         fatal=False))
                     continue
-                format_id = media.get('quality')
-                formats.append({
-                    'url': format_url,
-                    'format_id': format_id,
-                    'height': int_or_none(format_id),
-                })
+                fmt['height'] = int_or_none(fmt.get('format_id'))
+                fmt['format_id'] = join_nonempty('ext', 'format_id', from_dict=fmt)
+                formats.append(fmt)
         if not formats:
-            video_url = self._html_search_regex(
-                r'<source src="(.+?)" type="video/mp4">', webpage, 'video URL')
-            formats.append({'url': video_url})
+            video_url = url_or_none(self._html_search_regex(
+                r'<source src="(.+?)" type="video/mp4">', webpage, 'video URL'))
+            if video_url:
+                formats.append({'url': video_url})
+
+        self._check_formats(formats, video_id)
         self._sort_formats(formats)
 
         thumbnail = self._og_search_thumbnail(webpage)