[vidto] Several simplifications and improvements

1. Use InfoExtractor._hidden_inputs
2. Fetch title from <title> tag
3. Cookies are preserved automatically
4. Use single quotes everywhere
5. Do not declare variables for one-time use only

youtube_dl/extractor/vidto.py

@@ -4,24 +4,24 @@ from __future__ import unicode_literals
 import time
 
 from .common import InfoExtractor
-from ..utils import encode_dict
-from ..compat import (
-    compat_urllib_request,
-    compat_urllib_parse
+from ..utils import (
+    encode_dict,
+    remove_end,
+    urlencode_postdata,
 )
+from ..compat import compat_urllib_request
 
 
 class VidtoIE(InfoExtractor):
     IE_NAME = 'vidto'
     IE_DESC = 'VidTo.me'
     _VALID_URL = r'https?://(?:www\.)?vidto\.me/(?P<id>[0-9a-zA-Z]+)\.html'
-    _HOST = 'vidto.me'
     _TEST = {
         'url': 'http://vidto.me/ku5glz52nqe1.html',
         'info_dict': {
             'id': 'ku5glz52nqe1',
             'ext': 'mp4',
-            'title': 'test.mp4'
+            'title': 'test'
         }
     }
 
@@ -29,41 +29,26 @@ class VidtoIE(InfoExtractor):
         video_id = self._match_id(url)
 
         page = self._download_webpage(
-            'http://%s/%s.html' % (self._HOST, video_id), video_id, 'Downloading video page')
-        hash_regex = r'<input type="hidden" name="hash" value="(.*)">'
-        hash_value = self._search_regex(hash_regex, page, 'hash', fatal=True)
-        title_regex = r'<input type="hidden" name="fname" value="(.*)">'
-        title = self._search_regex(title_regex, page, 'title', fatal=False)
-        id_regex = r'<input type="hidden" name="id" value="(.*)">'
-        id_value = self._search_regex(id_regex, page, 'id', fatal=True)
-        cookies = self._get_cookies('http://%s/%s.html' % (self._HOST, video_id))
+            'http://vidto.me/%s.html' % video_id, video_id, 'Downloading video page')
 
-        form_str = {
-            'op': 'download1',
-            'imhuman': 'Proceed to video',
-            'usr_login': '',
-            'id': id_value,
-            'fname': title,
-            'referer': '',
-            'hash': hash_value,
-        }
-        post_data = compat_urllib_parse.urlencode(encode_dict(form_str)).encode('ascii')
-        req = compat_urllib_request.Request(url, post_data)
-        req.add_header('Content-type', 'application/x-www-form-urlencoded')
-        cookie_string = ""
-        for key in cookies.keys():
-            cookie_string += "%s=%s;" % (key, cookies[key].value)
+        title = remove_end(self._html_search_regex(
+            r'<Title>\s*([^<]+)\s*</Title>', page, 'title'), ' - Vidto')
 
-        req.add_header('Cookie', '%s' % cookie_string)
+        hidden_fields = self._hidden_inputs(page)
 
-        self.to_screen("Waiting for countdown...")
+        self.to_screen('Waiting for countdown...')
         time.sleep(7)
+
+        req = compat_urllib_request.Request(
+            url, urlencode_postdata(encode_dict(hidden_fields)))
+        req.add_header('Content-type', 'application/x-www-form-urlencoded')
+
         post_result = self._download_webpage(
             req, video_id,
             note='Proceed to video...', errnote='unable to proceed')
 
-        file_link_regex = r'file_link\s*=\s*\'(https?:\/\/[0-9a-zA-z.\/\-_]+)'
-        file_link = self._search_regex(file_link_regex, post_result, 'file_link')
+        file_link = self._search_regex(
+            r'file_link\s*=\s*\'(https?:\/\/[0-9a-zA-z.\/\-_]+)', post_result, 'file_link')
 
         return {
             'id': video_id,