1 files changed, 80 insertions, 0 deletions
diff --git a/youtube_dl/extractor/subtitles.py b/youtube_dl/extractor/subtitles.py
new file mode 100644
index 000000000..89864e5d7
--- /dev/null
+++ b/youtube_dl/extractor/subtitles.py
@@ -0,0 +1,80 @@
+import socket
+
+from .common import InfoExtractor
+
+from ..utils import (
+    compat_http_client,
+    compat_urllib_error,
+    compat_urllib_request,
+    compat_str,
+)
+
+
+class SubtitlesIE(InfoExtractor):
+
+    def report_video_subtitles_available(self, video_id, sub_lang_list):
+        """Report available subtitles."""
+        sub_lang = ",".join(list(sub_lang_list.keys()))
+        self.to_screen(u'%s: Available subtitles for video: %s' % (video_id, sub_lang))
+
+    def _list_available_subtitles(self, video_id):
+        sub_lang_list = self._get_available_subtitles(video_id)
+        self.report_video_subtitles_available(video_id, sub_lang_list)
+
+    def _extract_subtitles(self, video_id):
+        """
+        Return a dictionary: {language: subtitles} or {} if the subtitles
+        couldn't be found
+        """
+        sub_lang_list = self._get_available_subtitles(video_id)
+        sub_format = self._downloader.params.get('subtitlesformat')
+        if  not sub_lang_list: #There was some error, it didn't get the available subtitles
+            return {}
+        if self._downloader.params.get('writesubtitles', False):
+            if self._downloader.params.get('subtitleslang', False):
+                sub_lang = self._downloader.params.get('subtitleslang')
+            elif 'en' in sub_lang_list:
+                sub_lang = 'en'
+            else:
+                sub_lang = list(sub_lang_list.keys())[0]
+            if not sub_lang in sub_lang_list:
+                self._downloader.report_warning(u'no closed captions found in the specified language "%s"' % sub_lang)
+                return {}
+            sub_lang_list = {sub_lang: sub_lang_list[sub_lang]}
+        subtitles = {}
+        for sub_lang in sub_lang_list:
+            subtitle = self._request_subtitle(sub_lang, sub_lang_list[sub_lang].encode('utf-8'), video_id, sub_format)
+            if subtitle:
+                subtitles[sub_lang] = subtitle
+        return subtitles
+
+    def _request_subtitle(self, sub_lang, sub_name, video_id, format):
+        """ Return the subtitle as a string or None if they are not found """
+        # return (u'Did not fetch video subtitles for %s' % sub_lang, None, None)
+        self.to_screen(u'%s: Downloading video subtitles for %s.%s' % (video_id, sub_lang, format))
+        url = self._get_subtitle_url(sub_lang, sub_name, video_id, format)
+        try:
+            sub = compat_urllib_request.urlopen(url).read().decode('utf-8')
+        except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
+            self._downloader.report_warning(u'unable to download video subtitles for %s: %s' % (sub_lang, compat_str(err)))
+            return
+        if not sub:
+            self._downloader.report_warning(u'Did not fetch video subtitles')
+            return
+        return sub
+
+    def _get_available_subtitles(self, video_id):
+        """Get available subtitles. Redefine in subclasses."""
+        """returns {(lang, url)} """
+        # return {}
+        pass
+
+    def _get_subtitle_url(self, sub_lang, sub_name, video_id, format):
+        """returns the url for the given subtitle. Redefine in subclasses."""
+        pass
+
+    def _request_automatic_caption(self, video_id, webpage):
+        """Request automatic caption. Redefine in subclasses."""
+        """returns a tuple of ... """
+        # return [(err_msg, None, None)]
+        pass