[infoq] Add audio only format if available (#11565)

* [infoq] Add audio only format if available

Refactor cookie code into a function.
Renamed formats to http_video, http_audio, rtmp_video
Renamed extract functions to video instead of videos as they return
one or no video.

* [infoq] Rename to _extract_cookies as it more than one

* [infoq] Remove redundant determine_ext

* [infoq] Add comment about hardcoded URL

* [infoq] Use _hidden_inputs instead of messy regex

* [infoq] Probe if audio URL is valid

Make it possible to pass headers to _is_valid_url

* [infoq] Add audio only test

2 files changed, 55 insertions, 12 deletions

diff --git a/youtube_dl/extractor/common.py b/youtube_dl/extractor/common.py
index 5a15a9536..2c8ec1417 100644
--- a/youtube_dl/extractor/common.py
+++ b/youtube_dl/extractor/common.py
@@ -1025,13 +1025,13 @@ class InfoExtractor(object):
                 unique_formats.append(f)
         formats[:] = unique_formats
 
-    def _is_valid_url(self, url, video_id, item='video'):
+    def _is_valid_url(self, url, video_id, item='video', headers={}):
         url = self._proto_relative_url(url, scheme='http:')
         # For now assume non HTTP(S) URLs always valid
         if not (url.startswith('http://') or url.startswith('https://')):
             return True
         try:
-            self._request_webpage(url, video_id, 'Checking %s URL' % item)
+            self._request_webpage(url, video_id, 'Checking %s URL' % item, headers=headers)
             return True
         except ExtractorError as e:
             if isinstance(e.cause, compat_urllib_error.URLError):
diff --git a/youtube_dl/extractor/infoq.py b/youtube_dl/extractor/infoq.py
index cca0b8a93..9fb71e8ef 100644
--- a/youtube_dl/extractor/infoq.py
+++ b/youtube_dl/extractor/infoq.py
@@ -4,7 +4,10 @@ from __future__ import unicode_literals
 
 import base64
 
-from ..compat import compat_urllib_parse_unquote
+from ..compat import (
+    compat_urllib_parse_unquote,
+    compat_urlparse,
+)
 from ..utils import determine_ext
 from .bokecc import BokeCCBaseIE
 
@@ -33,9 +36,21 @@ class InfoQIE(BokeCCBaseIE):
             'ext': 'flv',
             'description': 'md5:308d981fb28fa42f49f9568322c683ff',
         },
+    }, {
+        'url': 'https://www.infoq.com/presentations/Simple-Made-Easy',
+        'md5': '0e34642d4d9ef44bf86f66f6399672db',
+        'info_dict': {
+            'id': 'Simple-Made-Easy',
+            'title': 'Simple Made Easy',
+            'ext': 'mp3',
+            'description': 'md5:3e0e213a8bbd074796ef89ea35ada25b',
+        },
+        'params': {
+            'format': 'bestaudio',
+        },
     }]
 
-    def _extract_rtmp_videos(self, webpage):
+    def _extract_rtmp_video(self, webpage):
         # The server URL is hardcoded
         video_url = 'rtmpe://video.infoq.com/cfx/st/'
 
@@ -47,28 +62,53 @@ class InfoQIE(BokeCCBaseIE):
         playpath = 'mp4:' + real_id
 
         return [{
-            'format_id': 'rtmp',
+            'format_id': 'rtmp_video',
             'url': video_url,
             'ext': determine_ext(playpath),
             'play_path': playpath,
         }]
 
-    def _extract_http_videos(self, webpage):
-        http_video_url = self._search_regex(r'P\.s\s*=\s*\'([^\']+)\'', webpage, 'video URL')
-
+    def _extract_cookies(self, webpage):
         policy = self._search_regex(r'InfoQConstants.scp\s*=\s*\'([^\']+)\'', webpage, 'policy')
         signature = self._search_regex(r'InfoQConstants.scs\s*=\s*\'([^\']+)\'', webpage, 'signature')
         key_pair_id = self._search_regex(r'InfoQConstants.sck\s*=\s*\'([^\']+)\'', webpage, 'key-pair-id')
+        return 'CloudFront-Policy=%s; CloudFront-Signature=%s; CloudFront-Key-Pair-Id=%s' % (
+            policy, signature, key_pair_id)
 
+    def _extract_http_video(self, webpage):
+        http_video_url = self._search_regex(r'P\.s\s*=\s*\'([^\']+)\'', webpage, 'video URL')
         return [{
-            'format_id': 'http',
+            'format_id': 'http_video',
             'url': http_video_url,
             'http_headers': {
-                'Cookie': 'CloudFront-Policy=%s; CloudFront-Signature=%s; CloudFront-Key-Pair-Id=%s' % (
-                    policy, signature, key_pair_id),
+                'Cookie': self._extract_cookies(webpage)
             },
         }]
 
+    def _extract_http_audio(self, webpage, video_id):
+        fields = self._hidden_inputs(webpage)
+        http_audio_url = fields['filename']
+        if http_audio_url is None:
+            return []
+
+        cookies_header = {'Cookie': self._extract_cookies(webpage)}
+
+        # base URL is found in the Location header in the response returned by
+        # GET https://www.infoq.com/mp3download.action?filename=... when logged in.
+        http_audio_url = compat_urlparse.urljoin('http://res.infoq.com/downloads/mp3downloads/', http_audio_url)
+
+        # audio file seem to be missing some times even if there is a download link
+        # so probe URL to make sure
+        if not self._is_valid_url(http_audio_url, video_id, headers=cookies_header):
+            return []
+
+        return [{
+            'format_id': 'http_audio',
+            'url': http_audio_url,
+            'vcodec': 'none',
+            'http_headers': cookies_header,
+        }]
+
     def _real_extract(self, url):
         video_id = self._match_id(url)
         webpage = self._download_webpage(url, video_id)
@@ -80,7 +120,10 @@ class InfoQIE(BokeCCBaseIE):
             # for China videos, HTTP video URL exists but always fails with 403
             formats = self._extract_bokecc_formats(webpage, video_id)
         else:
-            formats = self._extract_rtmp_videos(webpage) + self._extract_http_videos(webpage)
+            formats = (
+                self._extract_rtmp_video(webpage) +
+                self._extract_http_video(webpage) +
+                self._extract_http_audio(webpage, video_id))
 
         self._sort_formats(formats)