[howstuffworks] Add extractor (#3500)

Content-length is invalid for final download links.

youtube_dl/extractor/__init__.py

@@ -126,6 +126,7 @@
 from .hentaistigma import HentaiStigmaIE
 from .hotnewhiphop import HotNewHipHopIE
 from .howcast import HowcastIE
+from .howstuffworks import HowStuffWorksIE
 from .huffpost import HuffPostIE
 from .hypem import HypemIE
 from .iconosquare import IconosquareIE

youtube_dl/extractor/howstuffworks.py

@@ -0,0 +1,134 @@
+from __future__ import unicode_literals
+
+import re
+import json
+import random
+import string
+
+from .common import InfoExtractor
+from ..utils import find_xpath_attr
+
+
+class HowStuffWorksIE(InfoExtractor):
+    _VALID_URL = r'https?://[\da-z-]+\.howstuffworks\.com/(?:[^/]+/)*\d+-(?P<id>.+?)-video\.htm'
+    _TESTS = [
+        {
+            'url': 'http://adventure.howstuffworks.com/5266-cool-jobs-iditarod-musher-video.htm',
+            'info_dict': {
+                'id': '450221',
+                'display_id': 'cool-jobs-iditarod-musher',
+                'ext': 'flv',
+                'title': 'Cool Jobs - Iditarod Musher',
+                'description': 'md5:82bb58438a88027b8186a1fccb365f90',
+                'thumbnail': 're:^https?://.*\.jpg$',
+            },
+            'params': {
+                # md5 is not consistent
+                'skip_download': True
+            }
+        },
+        {
+            'url': 'http://adventure.howstuffworks.com/39516-deadliest-catch-jakes-farewell-pots-video.htm',
+            'info_dict': {
+                'id': '553470',
+                'display_id': 'deadliest-catch-jakes-farewell-pots',
+                'ext': 'mp4',
+                'title': 'Deadliest Catch: Jake\'s Farewell Pots',
+                'description': 'md5:9632c346d5e43ee238028c9cefd8dbbc',
+                'thumbnail': 're:^https?://.*\.jpg$',
+            },
+            'params': {
+                # md5 is not consistent
+                'skip_download': True
+            }
+        },
+        {
+            'url': 'http://entertainment.howstuffworks.com/arts/2706-sword-swallowing-1-by-dan-meyer-video.htm',
+            'info_dict': {
+                'id': '440011',
+                'display_id': 'sword-swallowing-1-by-dan-meyer',
+                'ext': 'flv',
+                'title': 'Sword Swallowing #1 by Dan Meyer',
+                'description': 'md5:b2409e88172913e2e7d3d1159b0ef735',
+                'thumbnail': 're:^https?://.*\.jpg$',
+            },
+            'params': {
+                # md5 is not consistent
+                'skip_download': True
+            }
+        },
+    ]
+
+    def _real_extract(self, url):
+        mobj = re.match(self._VALID_URL, url)
+        display_id = mobj.group('id')
+        webpage = self._download_webpage(url, display_id)
+
+        content_id = self._search_regex(r'var siteSectionId="(\d+)";', webpage, 'content id')
+
+        mp4 = self._search_regex(
+            r'''(?xs)var\s+clip\s*=\s*{\s*
+                .+?\s*
+                content_id\s*:\s*%s\s*,\s*
+                .+?\s*
+                mp4\s*:\s*\[(.*?),?\]\s*
+                };\s*
+                videoData\.push\(clip\);''' % content_id,
+            webpage, 'mp4', fatal=False, default=None)
+
+        smil = self._download_xml(
+            'http://services.media.howstuffworks.com/videos/%s/smil-service.smil' % content_id,
+            content_id, 'Downloading video SMIL')
+
+        http_base = find_xpath_attr(
+            smil,
+            './{0}head/{0}meta'.format('{http://www.w3.org/2001/SMIL20/Language}'),
+            'name',
+            'httpBase').get('content')
+
+        def random_string(str_len=0):
+            return ''.join([random.choice(string.ascii_uppercase) for _ in range(str_len)])
+
+        URL_SUFFIX = '?v=2.11.3&fp=LNX 11,2,202,356&r=%s&g=%s' % (random_string(5), random_string(12))
+
+        formats = []
+
+        if mp4:
+            for video in json.loads('[%s]' % mp4):
+                bitrate = video['bitrate']
+                fmt = {
+                    'url': video['src'].replace('http://pmd.video.howstuffworks.com', http_base) + URL_SUFFIX,
+                    'format_id': bitrate,
+                }
+                m = re.search(r'(?P<vbr>\d+)[Kk]', bitrate)
+                if m:
+                    fmt['vbr'] = int(m.group('vbr'))
+                formats.append(fmt)
+        else:
+            for video in smil.findall(
+                    './/{0}body/{0}switch/{0}video'.format('{http://www.w3.org/2001/SMIL20/Language}')):
+                vbr = int(video.attrib['system-bitrate']) / 1000
+                formats.append({
+                    'url': '%s/%s%s' % (http_base, video.attrib['src'], URL_SUFFIX),
+                    'format_id': '%dk' % vbr,
+                    'vbr': vbr,
+                })
+
+        self._sort_formats(formats)
+
+        title = self._og_search_title(webpage)
+        TITLE_SUFFIX = ' : HowStuffWorks'
+        if title.endswith(TITLE_SUFFIX):
+            title = title[:-len(TITLE_SUFFIX)]
+
+        description = self._og_search_description(webpage)
+        thumbnail = self._og_search_thumbnail(webpage)
+
+        return {
+            'id': content_id,
+            'display_id': display_id,
+            'title': title,
+            'description': description,
+            'thumbnail': thumbnail,
+            'formats': formats,
+        }