[dailymotion] Added support for subtitles + new InfoExtractor for

generic subtitle download.

The idea is that all subtitle downloaders must descend from SubtitlesIE
and implement only three basic methods to achieve the complete subtitle
download functionality. This will allow to reduce the code in YoutubeIE
once it is rewritten.

test/test_dailymotion_subtitles.py

@@ -0,0 +1,96 @@
+#!/usr/bin/env python
+
+import sys
+import unittest
+import json
+import io
+import hashlib
+
+# Allow direct execution
+import os
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from youtube_dl.extractor import DailymotionIE
+from youtube_dl.utils import *
+from helper import FakeYDL
+
+md5 = lambda s: hashlib.md5(s.encode('utf-8')).hexdigest()
+TEST_URL = 'http://www.dailymotion.com/video/xczg00'
+
+class TestDailymotionSubtitles(unittest.TestCase):
+    def setUp(self):
+        DL = FakeYDL()
+        DL.params['allsubtitles'] = False
+        DL.params['writesubtitles'] = False
+        DL.params['subtitlesformat'] = 'srt'
+        DL.params['listsubtitles'] = False
+    def test_no_subtitles(self):
+        DL = FakeYDL()
+        DL.params['writesubtitles'] = False
+        IE = DailymotionIE(DL)
+        info_dict = IE.extract(TEST_URL)
+        subtitles = info_dict[0]['subtitles']
+        self.assertEqual(subtitles, None)
+    def test_subtitles(self):
+        DL = FakeYDL()
+        DL.params['writesubtitles'] = True
+        IE = DailymotionIE(DL)
+        info_dict = IE.extract(TEST_URL)
+        sub = info_dict[0]['subtitles']['en']
+        self.assertEqual(md5(sub), '976553874490cba125086bbfea3ff76f')
+    def test_subtitles_fr(self):
+        DL = FakeYDL()
+        DL.params['writesubtitles'] = True
+        DL.params['subtitleslang'] = 'fr'
+        IE = DailymotionIE(DL)
+        info_dict = IE.extract(TEST_URL)
+        sub = info_dict[0]['subtitles']['fr']
+        self.assertEqual(md5(sub), '594564ec7d588942e384e920e5341792')
+    def test_onlysubtitles(self):
+        DL = FakeYDL()
+        DL.params['writesubtitles'] = True
+        DL.params['onlysubtitles'] = True
+        IE = DailymotionIE(DL)
+        info_dict = IE.extract(TEST_URL)
+        sub = info_dict[0]['subtitles']['en']
+        self.assertEqual(md5(sub), '976553874490cba125086bbfea3ff76f')
+    def test_allsubtitles(self):
+        DL = FakeYDL()
+        DL.params['allsubtitles'] = True
+        IE = DailymotionIE(DL)
+        info_dict = IE.extract(TEST_URL)
+        subtitles = info_dict[0]['subtitles']
+        self.assertEqual(len(subtitles.keys()), 5)
+    # def test_subtitles_sbv_format(self):
+    #     DL = FakeYDL()
+    #     DL.params['writesubtitles'] = True
+    #     DL.params['subtitlesformat'] = 'sbv'
+    #     IE = DailymotionIE(DL)
+    #     info_dict = IE.extract(TEST_URL)
+    #     sub = info_dict[0]['subtitles'][0]
+    #     self.assertEqual(md5(sub), '13aeaa0c245a8bed9a451cb643e3ad8b')
+    # def test_subtitles_vtt_format(self):
+    #     DL = FakeYDL()
+    #     DL.params['writesubtitles'] = True
+    #     DL.params['subtitlesformat'] = 'vtt'
+    #     IE = DailymotionIE(DL)
+    #     info_dict = IE.extract(TEST_URL)
+    #     sub = info_dict[0]['subtitles'][0]
+    #     self.assertEqual(md5(sub), '356cdc577fde0c6783b9b822e7206ff7')
+    def test_list_subtitles(self):
+        DL = FakeYDL()
+        DL.params['listsubtitles'] = True
+        IE = DailymotionIE(DL)
+        info_dict = IE.extract(TEST_URL)
+        self.assertEqual(info_dict, None)
+    def test_automatic_captions(self):
+        DL = FakeYDL()
+        DL.params['writeautomaticsub'] = True
+        DL.params['subtitleslang'] = 'en'
+        IE = DailymotionIE(DL)
+        info_dict = IE.extract(TEST_URL)
+        sub = info_dict[0]['subtitles']
+        self.assertTrue(len(sub) == 0)
+
+if __name__ == '__main__':
+    unittest.main()