[openload] Fix extraction (closes #10408)

Thanks @yokrysty for the algorithm

ChangeLog

@@ -1,3 +1,9 @@
+version <unreleased>
+
+Extractors
+* [openload] Fix extraction (#10408)
+
+
 version 2016.08.22
 
 Core

youtube_dl/extractor/openload.py

@@ -1,12 +1,12 @@
 # coding: utf-8
 from __future__ import unicode_literals, division
 
-import math
-
 from .common import InfoExtractor
-from ..compat import compat_chr
+from ..compat import (
+    compat_chr,
+    compat_ord,
+)
 from ..utils import (
-    decode_png,
     determine_ext,
     ExtractorError,
 )
@@ -42,71 +42,26 @@ class OpenloadIE(InfoExtractor):
 
     def _real_extract(self, url):
         video_id = self._match_id(url)
-        webpage = self._download_webpage(url, video_id)
+        webpage = self._download_webpage('https://openload.co/embed/%s/' % video_id, video_id)
 
-        if 'File not found' in webpage:
+        if 'File not found' in webpage or 'deleted by the owner' in webpage:
             raise ExtractorError('File not found', expected=True)
 
-        # The following extraction logic is proposed by @Belderak and @gdkchan
-        # and declared to be used freely in youtube-dl
-        # See https://github.com/rg3/youtube-dl/issues/9706
-
-        numbers_js = self._download_webpage(
-            'https://openload.co/assets/js/obfuscator/n.js', video_id,
-            note='Downloading signature numbers')
-        signums = self._search_regex(
-            r'window\.signatureNumbers\s*=\s*[\'"](?P<data>[a-z]+)[\'"]',
-            numbers_js, 'signature numbers', group='data')
-
-        linkimg_uri = self._search_regex(
-            r'<img[^>]+id="linkimg"[^>]+src="([^"]+)"', webpage, 'link image')
-        linkimg = self._request_webpage(
-            linkimg_uri, video_id, note=False).read()
-
-        width, height, pixels = decode_png(linkimg)
-
-        output = ''
-        for y in range(height):
-            for x in range(width):
-                r, g, b = pixels[y][3 * x:3 * x + 3]
-                if r == 0 and g == 0 and b == 0:
-                    break
-                else:
-                    output += compat_chr(r)
-                    output += compat_chr(g)
-                    output += compat_chr(b)
-
-        img_str_length = len(output) // 200
-        img_str = [[0 for x in range(img_str_length)] for y in range(10)]
-
-        sig_str_length = len(signums) // 260
-        sig_str = [[0 for x in range(sig_str_length)] for y in range(10)]
+        # The following decryption algorithm is written by @yokrysty and
+        # declared to be freely used in youtube-dl
+        # See https://github.com/rg3/youtube-dl/issues/10408
+        enc_data = self._html_search_regex(
+            r'<span[^>]+id="hiddenurl"[^>]*>([^<]+)</span>', webpage, 'encrypted data')
 
-        for i in range(10):
-            for j in range(img_str_length):
-                begin = i * img_str_length * 20 + j * 20
-                img_str[i][j] = output[begin:begin + 20]
-            for j in range(sig_str_length):
-                begin = i * sig_str_length * 26 + j * 26
-                sig_str[i][j] = signums[begin:begin + 26]
+        video_url_chars = []
 
-        parts = []
-        # TODO: find better names for str_, chr_ and sum_
-        str_ = ''
-        for i in [2, 3, 5, 7]:
-            str_ = ''
-            sum_ = float(99)
-            for j in range(len(sig_str[i])):
-                for chr_idx in range(len(img_str[i][j])):
-                    if sum_ > float(122):
-                        sum_ = float(98)
-                    chr_ = compat_chr(int(math.floor(sum_)))
-                    if sig_str[i][j][chr_idx] == chr_ and j >= len(str_):
-                        sum_ += float(2.5)
-                        str_ += img_str[i][j][chr_idx]
-            parts.append(str_.replace(',', ''))
+        for c in enc_data:
+            j = compat_ord(c)
+            if j >= 33 and j <= 126:
+                j = ((j + 14) % 94) + 33
+            video_url_chars += compat_chr(j)
 
-        video_url = 'https://openload.co/stream/%s~%s~%s~%s' % (parts[3], parts[1], parts[2], parts[0])
+        video_url = 'https://openload.co/stream/%s?mime=true' % ''.join(video_url_chars)
 
         title = self._og_search_title(webpage, default=None) or self._search_regex(
             r'<span[^>]+class=["\']title["\'][^>]*>([^<]+)', webpage,