-            try:
-                # The DASH manifest used needs to be the one from the original video_webpage.
-                # The one found in get_video_info seems to be using different signatures.
-                # However, in the case of an age restriction there won't be any embedded dashmpd in the video_webpage.
-                # Luckily, it seems, this case uses some kind of default signature (len == 86), so the
-                # combination of get_video_info and the _static_decrypt_signature() decryption fallback will work here.
-                dash_manifest_url = video_info.get('dashmpd')[0]
-
-                def decrypt_sig(mobj):
-                    s = mobj.group(1)
-                    dec_s = self._decrypt_signature(s, video_id, player_url, age_gate)
-                    return '/signature/%s' % dec_s
-                dash_manifest_url = re.sub(r'/s/([\w\.]+)', decrypt_sig, dash_manifest_url)
-                dash_doc = self._download_xml(
-                    dash_manifest_url, video_id,
-                    note='Downloading DASH manifest',
-                    errnote='Could not download DASH manifest')
-                for r in dash_doc.findall('.//{urn:mpeg:DASH:schema:MPD:2011}Representation'):
-                    url_el = r.find('{urn:mpeg:DASH:schema:MPD:2011}BaseURL')
-                    if url_el is None:
-                        continue
-                    format_id = r.attrib['id']
-                    video_url = url_el.text
-                    filesize = int_or_none(url_el.attrib.get('{http://youtube.com/yt/2012/10/10}contentLength'))
-                    f = {
-                        'format_id': format_id,
-                        'url': video_url,
-                        'width': int_or_none(r.attrib.get('width')),
-                        'tbr': int_or_none(r.attrib.get('bandwidth'), 1000),
-                        'asr': int_or_none(r.attrib.get('audioSamplingRate')),
-                        'filesize': filesize,
-                    }
-                    try:
-                        existing_format = next(
-                            fo for fo in formats
-                            if fo['format_id'] == format_id)
-                    except StopIteration:
-                        f.update(self._formats.get(format_id, {}))
-                        formats.append(f)
-                    else:
-                        existing_format.update(f)
-
-            except (ExtractorError, KeyError) as e:
-                self.report_warning('Skipping DASH manifest: %r' % e, video_id)
+            dash_mpd = video_info.get('dashmpd')
+            if dash_mpd:
+                dash_manifest_url = dash_mpd[0]
+                try:
+                    dash_formats = self._parse_dash_manifest(
+                        video_id, dash_manifest_url, player_url, age_gate)
+                except (ExtractorError, KeyError) as e:
+                    self.report_warning(
+                        'Skipping DASH manifest: %r' % e, video_id)
+                else:
+                    # Hide the formats we found through non-DASH
+                    dash_keys = set(df['format_id'] for df in dash_formats)
+                    for f in formats:
+                        if f['format_id'] in dash_keys:
+                            f['format_id'] = 'nondash-%s' % f['format_id']
+                            f['preference'] = f.get('preference', 0) - 10000
+                    formats.extend(dash_formats)
+
+        # Check for malformed aspect ratio
+        stretched_m = re.search(
+            r'<meta\s+property="og:video:tag".*?content="yt:stretch=(?P<w>[0-9]+):(?P<h>[0-9]+)">',
+            video_webpage)
+        if stretched_m:
+            ratio = float(stretched_m.group('w')) / float(stretched_m.group('h'))
+            for f in formats:
+                if f.get('vcodec') != 'none':
+                    f['stretched_ratio'] = ratio