aboutsummaryrefslogtreecommitdiff
path: root/youtube_dl/extractor/youtube.py
blob: 6384095f9f5452e9565d69ff39b9f19fa8331c74 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
# coding: utf-8

import collections
import errno
import io
import itertools
import json
import os.path
import re
import struct
import traceback
import zlib

from .common import InfoExtractor, SearchInfoExtractor
from .subtitles import SubtitlesInfoExtractor
from ..jsinterp import JSInterpreter
from ..utils import (
    compat_chr,
    compat_parse_qs,
    compat_urllib_parse,
    compat_urllib_request,
    compat_urlparse,
    compat_str,

    clean_html,
    get_cachedir,
    get_element_by_id,
    get_element_by_attribute,
    ExtractorError,
    int_or_none,
    PagedList,
    unescapeHTML,
    unified_strdate,
    orderedSet,
    write_json_file,
    uppercase_escape,
)

class YoutubeBaseInfoExtractor(InfoExtractor):
    """Provide base functions for Youtube extractors"""
    _LOGIN_URL = 'https://accounts.google.com/ServiceLogin'
    _LANG_URL = r'https://www.youtube.com/?hl=en&persist_hl=1&gl=US&persist_gl=1&opt_out_ackd=1'
    _AGE_URL = 'https://www.youtube.com/verify_age?next_url=/&gl=US&hl=en'
    _NETRC_MACHINE = 'youtube'
    # If True it will raise an error if no login info is provided
    _LOGIN_REQUIRED = False

    def _set_language(self):
        return bool(self._download_webpage(
            self._LANG_URL, None,
            note=u'Setting language', errnote='unable to set language',
            fatal=False))

    def _login(self):
        (username, password) = self._get_login_info()
        # No authentication to be performed
        if username is None:
            if self._LOGIN_REQUIRED:
                raise ExtractorError(u'No login info available, needed for using %s.' % self.IE_NAME, expected=True)
            return False

        login_page = self._download_webpage(
            self._LOGIN_URL, None,
            note=u'Downloading login page',
            errnote=u'unable to fetch login page', fatal=False)
        if login_page is False:
            return

        galx = self._search_regex(r'(?s)<input.+?name="GALX".+?value="(.+?)"',
                                  login_page, u'Login GALX parameter')

        # Log in
        login_form_strs = {
                u'continue': u'https://www.youtube.com/signin?action_handle_signin=true&feature=sign_in_button&hl=en_US&nomobiletemp=1',
                u'Email': username,
                u'GALX': galx,
                u'Passwd': password,
                u'PersistentCookie': u'yes',
                u'_utf8': u'霱',
                u'bgresponse': u'js_disabled',
                u'checkConnection': u'',
                u'checkedDomains': u'youtube',
                u'dnConn': u'',
                u'pstMsg': u'0',
                u'rmShown': u'1',
                u'secTok': u'',
                u'signIn': u'Sign in',
                u'timeStmp': u'',
                u'service': u'youtube',
                u'uilel': u'3',
                u'hl': u'en_US',
        }
        # Convert to UTF-8 *before* urlencode because Python 2.x's urlencode
        # chokes on unicode
        login_form = dict((k.encode('utf-8'), v.encode('utf-8')) for k,v in login_form_strs.items())
        login_data = compat_urllib_parse.urlencode(login_form).encode('ascii')

        req = compat_urllib_request.Request(self._LOGIN_URL, login_data)
        login_results = self._download_webpage(
            req, None,
            note=u'Logging in', errnote=u'unable to log in', fatal=False)
        if login_results is False:
            return False
        if re.search(r'(?i)<form[^>]* id="gaia_loginform"', login_results) is not None:
            self._downloader.report_warning(u'unable to log in: bad username or password')
            return False
        return True

    def _confirm_age(self):
        age_form = {
            'next_url': '/',
            'action_confirm': 'Confirm',
        }
        req = compat_urllib_request.Request(self._AGE_URL,
            compat_urllib_parse.urlencode(age_form).encode('ascii'))

        self._download_webpage(
            req, None,
            note=u'Confirming age', errnote=u'Unable to confirm age')
        return True

    def _real_initialize(self):
        if self._downloader is None:
            return
        if not self._set_language():
            return
        if not self._login():
            return
        self._confirm_age()


class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
    IE_DESC = u'YouTube.com'
    _VALID_URL = r"""(?x)^
                     (
                         (?:https?://|//)?                                    # http(s):// or protocol-independent URL (optional)
                         (?:(?:(?:(?:\w+\.)?[yY][oO][uU][tT][uU][bB][eE](?:-nocookie)?\.com/|
                            (?:www\.)?deturl\.com/www\.youtube\.com/|
                            (?:www\.)?pwnyoutube\.com/|
                            (?:www\.)?yourepeat\.com/|
                            tube\.majestyc\.net/|
                            youtube\.googleapis\.com/)                        # the various hostnames, with wildcard subdomains
                         (?:.*?\#/)?                                          # handle anchor (#/) redirect urls
                         (?:                                                  # the various things that can precede the ID:
                             (?:(?:v|embed|e)/)                               # v/ or embed/ or e/
                             |(?:                                             # or the v= param in all its forms
                                 (?:(?:watch|movie)(?:_popup)?(?:\.php)?/?)?  # preceding watch(_popup|.php) or nothing (like /?v=xxxx)
                                 (?:\?|\#!?)                                  # the params delimiter ? or # or #!
                                 (?:.*?&)?                                    # any other preceding param (like /?s=tuff&v=xxxx)
                                 v=
                             )
                         ))
                         |youtu\.be/                                          # just youtu.be/xxxx
                         )
                     )?                                                       # all until now is optional -> you can pass the naked ID
                     ([0-9A-Za-z_-]{11})                                      # here is it! the YouTube video ID
                     (?(1).+)?                                                # if we found the ID, everything can follow
                     $"""
    _NEXT_URL_RE = r'[\?&]next_url=([^&]+)'
    _formats = {
        '5': {'ext': 'flv', 'width': 400, 'height': 240},
        '6': {'ext': 'flv', 'width': 450, 'height': 270},
        '13': {'ext': '3gp'},
        '17': {'ext': '3gp', 'width': 176, 'height': 144},
        '18': {'ext': 'mp4', 'width': 640, 'height': 360},
        '22': {'ext': 'mp4', 'width': 1280, 'height': 720},
        '34': {'ext': 'flv', 'width': 640, 'height': 360},
        '35': {'ext': 'flv', 'width': 854, 'height': 480},
        '36': {'ext': '3gp', 'width': 320, 'height': 240},
        '37': {'ext': 'mp4', 'width': 1920, 'height': 1080},
        '38': {'ext': 'mp4', 'width': 4096, 'height': 3072},
        '43': {'ext': 'webm', 'width': 640, 'height': 360},
        '44': {'ext': 'webm', 'width': 854, 'height': 480},
        '45': {'ext': 'webm', 'width': 1280, 'height': 720},
        '46': {'ext': 'webm', 'width': 1920, 'height': 1080},


        # 3d videos
        '82': {'ext': 'mp4', 'height': 360, 'format_note': '3D', 'preference': -20},
        '83': {'ext': 'mp4', 'height': 480, 'format_note': '3D', 'preference': -20},
        '84': {'ext': 'mp4', 'height': 720, 'format_note': '3D', 'preference': -20},
        '85': {'ext': 'mp4', 'height': 1080, 'format_note': '3D', 'preference': -20},
        '100': {'ext': 'webm', 'height': 360, 'format_note': '3D', 'preference': -20},
        '101': {'ext': 'webm', 'height': 480, 'format_note': '3D', 'preference': -20},
        '102': {'ext': 'webm', 'height': 720, 'format_note': '3D', 'preference': -20},

        # Apple HTTP Live Streaming
        '92': {'ext': 'mp4', 'height': 240, 'format_note': 'HLS', 'preference': -10},
        '93': {'ext': 'mp4', 'height': 360, 'format_note': 'HLS', 'preference': -10},
        '94': {'ext': 'mp4', 'height': 480, 'format_note': 'HLS', 'preference': -10},
        '95': {'ext': 'mp4', 'height': 720, 'format_note': 'HLS', 'preference': -10},
        '96': {'ext': 'mp4', 'height': 1080, 'format_note': 'HLS', 'preference': -10},
        '132': {'ext': 'mp4', 'height': 240, 'format_note': 'HLS', 'preference': -10},
        '151': {'ext': 'mp4', 'height': 72, 'format_note': 'HLS', 'preference': -10},

        # DASH mp4 video
        '133': {'ext': 'mp4', 'height': 240, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
        '134': {'ext': 'mp4', 'height': 360, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
        '135': {'ext': 'mp4', 'height': 480, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
        '136': {'ext': 'mp4', 'height': 720, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
        '137': {'ext': 'mp4', 'height': 1080, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
        '138': {'ext': 'mp4', 'height': 2160, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
        '160': {'ext': 'mp4', 'height': 144, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},
        '264': {'ext': 'mp4', 'height': 1440, 'format_note': 'DASH video', 'acodec': 'none', 'preference': -40},

        # Dash mp4 audio
        '139': {'ext': 'm4a', 'format_note': 'DASH audio', 'vcodec': 'none', 'abr': 48, 'preference': -50},
        '140': {'ext': 'm4a', 'format_note': 'DASH audio', 'vcodec': 'none', 'abr': 128, 'preference': -50},
        '141': {'ext': 'm4a', 'format_note': 'DASH audio', 'vcodec': 'none', 'abr': 256, 'preference': -50},

        # Dash webm
        '167': {'ext': 'webm', 'height': 360, 'width': 640, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
        '168': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
        '169': {'ext': 'webm', 'height': 720, 'width': 1280, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
        '170': {'ext': 'webm', 'height': 1080, 'width': 1920, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
        '218': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
        '219': {'ext': 'webm', 'height': 480, 'width': 854, 'format_note': 'DASH video', 'acodec': 'none', 'container': 'webm', 'vcodec': 'VP8', 'acodec': 'none', 'preference': -40},
        '242': {'ext': 'webm', 'height': 240, 'format_note': 'DASH webm', 'preference': -40},
        '243': {'ext': 'webm', 'height': 360, 'format_note': 'DASH webm', 'preference': -40},
        '244': {'ext': 'webm', 'height': 480, 'format_note': 'DASH webm', 'preference': -40},
        '245': {'ext': 'webm', 'height': 480, 'format_note': 'DASH webm', 'preference': -40},
        '246': {'ext': 'webm', 'height': 480, 'format_note': 'DASH webm', 'preference': -40},
        '247': {'ext': 'webm', 'height': 720, 'format_note': 'DASH webm', 'preference': -40},
        '248': {'ext': 'webm', 'height': 1080, 'format_note': 'DASH webm', 'preference': -40},

        # Dash webm audio
        '171': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH webm audio', 'abr': 48, 'preference': -50},
        '172': {'ext': 'webm', 'vcodec': 'none', 'format_note': 'DASH webm audio', 'abr': 256, 'preference': -50},

        # RTMP (unnamed)
        '_rtmp': {'protocol': 'rtmp'},
    }

    IE_NAME = u'youtube'
    _TESTS = [
        {
            u"url":  u"http://www.youtube.com/watch?v=BaW_jenozKc",
            u"file":  u"BaW_jenozKc.mp4",
            u"info_dict": {
                u"title": u"youtube-dl test video \"'/\\ä↭𝕐",
                u"uploader": u"Philipp Hagemeister",
                u"uploader_id": u"phihag",
                u"upload_date": u"20121002",
                u"description": u"test chars:  \"'/\\ä↭𝕐\ntest URL: https://github.com/rg3/youtube-dl/issues/1892\n\nThis is a test video for youtube-dl.\n\nFor more information, contact phihag@phihag.de ."
            }
        },
        {
            u"url":  u"http://www.youtube.com/watch?v=UxxajLWwzqY",
            u"file":  u"UxxajLWwzqY.mp4",
            u"note": u"Test generic use_cipher_signature video (#897)",
            u"info_dict": {
                u"upload_date": u"20120506",
                u"title": u"Icona Pop - I Love It (feat. Charli XCX) [OFFICIAL VIDEO]",
                u"description": u"md5:5b292926389560516e384ac437c0ec07",
                u"uploader": u"Icona Pop",
                u"uploader_id": u"IconaPop"
            }
        },
        {
            u"url":  u"https://www.youtube.com/watch?v=07FYdnEawAQ",
            u"file":  u"07FYdnEawAQ.mp4",
            u"note": u"Test VEVO video with age protection (#956)",
            u"info_dict": {
                u"upload_date": u"20130703",
                u"title": u"Justin Timberlake - Tunnel Vision (Explicit)",
                u"description": u"md5:64249768eec3bc4276236606ea996373",
                u"uploader": u"justintimberlakeVEVO",
                u"uploader_id": u"justintimberlakeVEVO"
            }
        },
        {
            u"url":  u"//www.YouTube.com/watch?v=yZIXLfi8CZQ",
            u"file":  u"yZIXLfi8CZQ.mp4",
            u"note": u"Embed-only video (#1746)",
            u"info_dict": {
                u"upload_date": u"20120608",
                u"title": u"Principal Sexually Assaults A Teacher - Episode 117 - 8th June 2012",
                u"description": u"md5:09b78bd971f1e3e289601dfba15ca4f7",
                u"uploader": u"SET India",
                u"uploader_id": u"setindia"
            }
        },
        {
            u"url": u"http://www.youtube.com/watch?v=a9LDPn-MO4I",
            u"file": u"a9LDPn-MO4I.m4a",
            u"note": u"256k DASH audio (format 141) via DASH manifest",
            u"info_dict": {
                u"upload_date": "20121002",
                u"uploader_id": "8KVIDEO",
                u"description": "No description available.",
                u"uploader": "8KVIDEO",
                u"title": "UHDTV TEST 8K VIDEO.mp4"
            },
            u"params": {
                u"youtube_include_dash_manifest": True,
                u"format": "141",
            },
        },
        # DASH manifest with encrypted signature
        {
            u'url': u'https://www.youtube.com/watch?v=IB3lcPjvWLA',
            u'info_dict': {
                u'id': u'IB3lcPjvWLA',
                u'ext': u'm4a',
                u'title': u'Afrojack - The Spark ft. Spree Wilson',
                u'description': u'md5:3199ed45ee8836572865580804d7ac0f',
                u'uploader': u'AfrojackVEVO',
                u'uploader_id': u'AfrojackVEVO',
                u'upload_date': u'20131011',
            },
            u"params": {
                u'youtube_include_dash_manifest': True,
                u'format': '141',
            },
        },
    ]


    @classmethod
    def suitable(cls, url):
        """Receives a URL and returns True if suitable for this IE."""
        if YoutubePlaylistIE.suitable(url): return False
        return re.match(cls._VALID_URL, url) is not None

    def __init__(self, *args, **kwargs):
        super(YoutubeIE, self).__init__(*args, **kwargs)
        self._player_cache = {}

    def report_video_info_webpage_download(self, video_id):
        """Report attempt to download video info webpage."""
        self.to_screen(u'%s: Downloading video info webpage' % video_id)

    def report_information_extraction(self, video_id):
        """Report attempt to extract video information."""
        self.to_screen(u'%s: Extracting video information' % video_id)

    def report_unavailable_format(self, video_id, format):
        """Report extracted video URL."""
        self.to_screen(u'%s: Format %s not available' % (video_id, format))

    def report_rtmp_download(self):
        """Indicate the download will use the RTMP protocol."""
        self.to_screen(u'RTMP download detected')

    def _extract_signature_function(self, video_id, player_url, slen):
        id_m = re.match(r'.*-(?P<id>[a-zA-Z0-9_-]+)\.(?P<ext>[a-z]+)$',
                        player_url)
        player_type = id_m.group('ext')
        player_id = id_m.group('id')

        # Read from filesystem cache
        func_id = '%s_%s_%d' % (player_type, player_id, slen)
        assert os.path.basename(func_id) == func_id
        cache_dir = get_cachedir(self._downloader.params)

        cache_enabled = cache_dir is not None
        if cache_enabled:
            cache_fn = os.path.join(os.path.expanduser(cache_dir),
                                    u'youtube-sigfuncs',
                                    func_id + '.json')
            try:
                with io.open(cache_fn, 'r', encoding='utf-8') as cachef:
                    cache_spec = json.load(cachef)
                return lambda s: u''.join(s[i] for i in cache_spec)
            except IOError:
                pass  # No cache available

        if player_type == 'js':
            code = self._download_webpage(
                player_url, video_id,
                note=u'Downloading %s player %s' % (player_type, player_id),
                errnote=u'Download of %s failed' % player_url)
            res = self._parse_sig_js(code)
        elif player_type == 'swf':
            urlh = self._request_webpage(
                player_url, video_id,
                note=u'Downloading %s player %s' % (player_type, player_id),
                errnote=u'Download of %s failed' % player_url)
            code = urlh.read()
            res = self._parse_sig_swf(code)
        else:
            assert False, 'Invalid player type %r' % player_type

        if cache_enabled:
            try:
                test_string = u''.join(map(compat_chr, range(slen)))
                cache_res = res(test_string)
                cache_spec = [ord(c) for c in cache_res]
                try:
                    os.makedirs(os.path.dirname(cache_fn))
                except OSError as ose:
                    if ose.errno != errno.EEXIST:
                        raise
                write_json_file(cache_spec, cache_fn)
            except Exception:
                tb = traceback.format_exc()
                self._downloader.report_warning(
                    u'Writing cache to %r failed: %s' % (cache_fn, tb))

        return res

    def _print_sig_code(self, func, slen):
        def gen_sig_code(idxs):
            def _genslice(start, end, step):
                starts = u'' if start == 0 else str(start)
                ends = (u':%d' % (end+step)) if end + step >= 0 else u':'
                steps = u'' if step == 1 else (u':%d' % step)
                return u's[%s%s%s]' % (starts, ends, steps)

            step = None
            start = '(Never used)'  # Quelch pyflakes warnings - start will be
                                    # set as soon as step is set
            for i, prev in zip(idxs[1:], idxs[:-1]):
                if step is not None:
                    if i - prev == step:
                        continue
                    yield _genslice(start, prev, step)
                    step = None
                    continue
                if i - prev in [-1, 1]:
                    step = i - prev
                    start = prev
                    continue
                else:
                    yield u's[%d]' % prev
            if step is None:
                yield u's[%d]' % i
            else:
                yield _genslice(start, i, step)

        test_string = u''.join(map(compat_chr, range(slen)))
        cache_res = func(test_string)
        cache_spec = [ord(c) for c in cache_res]
        expr_code = u' + '.join(gen_sig_code(cache_spec))
        code = u'if len(s) == %d:\n    return %s\n' % (slen, expr_code)
        self.to_screen(u'Extracted signature function:\n' + code)

    def _parse_sig_js(self, jscode):
        funcname = self._search_regex(
            r'signature=([a-zA-Z]+)', jscode,
             u'Initial JS player signature function name')

        jsi = JSInterpreter(jscode)
        initial_function = jsi.extract_function(funcname)
        return lambda s: initial_function([s])

    def _parse_sig_swf(self, file_contents):
        if file_contents[1:3] != b'WS':
            raise ExtractorError(
                u'Not an SWF file; header is %r' % file_contents[:3])
        if file_contents[:1] == b'C':
            content = zlib.decompress(file_contents[8:])
        else:
            raise NotImplementedError(u'Unsupported compression format %r' %
                                      file_contents[:1])

        def extract_tags(content):
            pos = 0
            while pos < len(content):
                header16 = struct.unpack('<H', content[pos:pos+2])[0]
                pos += 2
                tag_code = header16 >> 6
                tag_len = header16 & 0x3f
                if tag_len == 0x3f:
                    tag_len = struct.unpack('<I', content[pos:pos+4])[0]
                    pos += 4
                assert pos+tag_len <= len(content)
                yield (tag_code, content[pos:pos+tag_len])
                pos += tag_len

        code_tag = next(tag
                        for tag_code, tag in extract_tags(content)
                        if tag_code == 82)
        p = code_tag.index(b'\0', 4) + 1
        code_reader = io.BytesIO(code_tag[p:])

        # Parse ABC (AVM2 ByteCode)
        def read_int(reader=None):
            if reader is None:
                reader = code_reader
            res = 0
            shift = 0
            for _ in range(5):
                buf = reader.read(1)
                assert len(buf) == 1
                b = struct.unpack('<B', buf)[0]
                res = res | ((b & 0x7f) << shift)
                if b & 0x80 == 0:
                    break
                shift += 7
            return res

        def u30(reader=None):
            res = read_int(reader)
            assert res & 0xf0000000 == 0
            return res
        u32 = read_int

        def s32(reader=None):
            v = read_int(reader)
            if v & 0x80000000 != 0:
                v = - ((v ^ 0xffffffff) + 1)
            return v

        def read_string(reader=None):
            if reader is None:
                reader = code_reader
            slen = u30(reader)
            resb = reader.read(slen)
            assert len(resb) == slen
            return resb.decode('utf-8')

        def read_bytes(count, reader=None):
            if reader is None:
                reader = code_reader
            resb = reader.read(count)
            assert len(resb) == count
            return resb

        def read_byte(reader=None):
            resb = read_bytes(1, reader=reader)
            res = struct.unpack('<B', resb)[0]
            return res

        # minor_version + major_version
        read_bytes(2 + 2)

        # Constant pool
        int_count = u30()
        for _c in range(1, int_count):
            s32()
        uint_count = u30()
        for _c in range(1, uint_count):
            u32()
        double_count = u30()
        read_bytes((double_count-1) * 8)
        string_count = u30()
        constant_strings = [u'']
        for _c in range(1, string_count):
            s = read_string()
            constant_strings.append(s)
        namespace_count = u30()
        for _c in range(1, namespace_count):
            read_bytes(1)  # kind
            u30()  # name
        ns_set_count = u30()
        for _c in range(1, ns_set_count):
            count = u30()
            for _c2 in range(count):
                u30()
        multiname_count = u30()
        MULTINAME_SIZES = {
            0x07: 2,  # QName
            0x0d: 2,  # QNameA
            0x0f: 1,  # RTQName
            0x10: 1,  # RTQNameA
            0x11: 0,  # RTQNameL
            0x12: 0,  # RTQNameLA
            0x09: 2,  # Multiname
            0x0e: 2,  # MultinameA
            0x1b: 1,  # MultinameL
            0x1c: 1,  # MultinameLA
        }
        multinames = [u'']
        for _c in range(1, multiname_count):
            kind = u30()
            assert kind in MULTINAME_SIZES, u'Invalid multiname kind %r' % kind
            if kind == 0x07:
                u30()  # namespace_idx
                name_idx = u30()
                multinames.append(constant_strings[name_idx])
            else:
                multinames.append('[MULTINAME kind: %d]' % kind)
                for _c2 in range(MULTINAME_SIZES[kind]):
                    u30()

        # Methods
        method_count = u30()
        MethodInfo = collections.namedtuple(
            'MethodInfo',
            ['NEED_ARGUMENTS', 'NEED_REST'])
        method_infos = []
        for method_id in range(method_count):
            param_count = u30()
            u30()  # return type
            for _ in range(param_count):
                u30()  # param type
            u30()  # name index (always 0 for youtube)
            flags = read_byte()
            if flags & 0x08 != 0:
                # Options present
                option_count = u30()
                for c in range(option_count):
                    u30()  # val
                    read_bytes(1)  # kind
            if flags & 0x80 != 0:
                # Param names present
                for _ in range(param_count):
                    u30()  # param name
            mi = MethodInfo(flags & 0x01 != 0, flags & 0x04 != 0)
            method_infos.append(mi)

        # Metadata
        metadata_count = u30()
        for _c in range(metadata_count):
            u30()  # name
            item_count = u30()
            for _c2 in range(item_count):
                u30()  # key
                u30()  # value

        def parse_traits_info():
            trait_name_idx = u30()
            kind_full = read_byte()
            kind = kind_full & 0x0f
            attrs = kind_full >> 4
            methods = {}
            if kind in [0x00, 0x06]:  # Slot or Const
                u30()  # Slot id
                u30()  # type_name_idx
                vindex = u30()
                if vindex != 0:
                    read_byte()  # vkind
            elif kind in [0x01, 0x02, 0x03]:  # Method / Getter / Setter
                u30()  # disp_id
                method_idx = u30()
                methods[multinames[trait_name_idx]] = method_idx
            elif kind == 0x04:  # Class
                u30()  # slot_id
                u30()  # classi
            elif kind == 0x05:  # Function
                u30()  # slot_id
                function_idx = u30()
                methods[function_idx] = multinames[trait_name_idx]
            else:
                raise ExtractorError(u'Unsupported trait kind %d' % kind)

            if attrs & 0x4 != 0:  # Metadata present
                metadata_count = u30()
                for _c3 in range(metadata_count):
                    u30()  # metadata index

            return methods

        # Classes
        TARGET_CLASSNAME = u'SignatureDecipher'
        searched_idx = multinames.index(TARGET_CLASSNAME)
        searched_class_id = None
        class_count = u30()
        for class_id in range(class_count):
            name_idx = u30()
            if name_idx == searched_idx:
                # We found the class we're looking for!
                searched_class_id = class_id
            u30()  # super_name idx
            flags = read_byte()
            if flags & 0x08 != 0:  # Protected namespace is present
                u30()  # protected_ns_idx
            intrf_count = u30()
            for _c2 in range(intrf_count):
                u30()
            u30()  # iinit
            trait_count = u30()
            for _c2 in range(trait_count):
                parse_traits_info()

        if searched_class_id is None:
            raise ExtractorError(u'Target class %r not found' %
                                 TARGET_CLASSNAME)

        method_names = {}
        method_idxs = {}
        for class_id in range(class_count):
            u30()  # cinit
            trait_count = u30()
            for _c2 in range(trait_count):
                trait_methods = parse_traits_info()
                if class_id == searched_class_id:
                    method_names.update(trait_methods.items())
                    method_idxs.update(dict(
                        (idx, name)
                        for name, idx in trait_methods.items()))

        # Scripts
        script_count = u30()
        for _c in range(script_count):
            u30()  # init
            trait_count = u30()
            for _c2 in range(trait_count):
                parse_traits_info()

        # Method bodies
        method_body_count = u30()
        Method = collections.namedtuple('Method', ['code', 'local_count'])
        methods = {}
        for _c in range(method_body_count):
            method_idx = u30()
            u30()  # max_stack
            local_count = u30()
            u30()  # init_scope_depth
            u30()  # max_scope_depth
            code_length = u30()
            code = read_bytes(code_length)
            if method_idx in method_idxs:
                m = Method(code, local_count)
                methods[method_idxs[method_idx]] = m
            exception_count = u30()
            for _c2 in range(exception_count):
                u30()  # from
                u30()  # to
                u30()  # target
                u30()  # exc_type
                u30()  # var_name
            trait_count = u30()
            for _c2 in range(trait_count):
                parse_traits_info()

        assert p + code_reader.tell() == len(code_tag)
        assert len(methods) == len(method_idxs)

        method_pyfunctions = {}

        def extract_function(func_name):
            if func_name in method_pyfunctions:
                return method_pyfunctions[func_name]
            if func_name not in methods:
                raise ExtractorError(u'Cannot find function %r' % func_name)
            m = methods[func_name]

            def resfunc(args):
                registers = ['(this)'] + list(args) + [None] * m.local_count
                stack = []
                coder = io.BytesIO(m.code)
                while True:
                    opcode = struct.unpack('!B', coder.read(1))[0]
                    if opcode == 36:  # pushbyte
                        v = struct.unpack('!B', coder.read(1))[0]
                        stack.append(v)
                    elif opcode == 44:  # pushstring
                        idx = u30(coder)
                        stack.append(constant_strings[idx])
                    elif opcode == 48:  # pushscope
                        # We don't implement the scope register, so we'll just
                        # ignore the popped value
                        stack.pop()
                    elif opcode == 70:  # callproperty
                        index = u30(coder)
                        mname = multinames[index]
                        arg_count = u30(coder)
                        args = list(reversed(
                            [stack.pop() for _ in range(arg_count)]))
                        obj = stack.pop()
                        if mname == u'split':
                            assert len(args) == 1
                            assert isinstance(args[0], compat_str)
                            assert isinstance(obj, compat_str)
                            if args[0] == u'':
                                res = list(obj)
                            else:
                                res = obj.split(args[0])
                            stack.append(res)
                        elif mname == u'slice':
                            assert len(args) == 1
                            assert isinstance(args[0], int)
                            assert isinstance(obj, list)
                            res = obj[args[0]:]
                            stack.append(res)
                        elif mname == u'join':
                            assert len(args) == 1
                            assert isinstance(args[0], compat_str)
                            assert isinstance(obj, list)
                            res = args[0].join(obj)
                            stack.append(res)
                        elif mname in method_pyfunctions:
                            stack.append(method_pyfunctions[mname](args))
                        else:
                            raise NotImplementedError(
                                u'Unsupported property %r on %r'
                                % (mname, obj))
                    elif opcode == 72:  # returnvalue
                        res = stack.pop()
                        return res
                    elif opcode == 79:  # callpropvoid
                        index = u30(coder)
                        mname = multinames[index]
                        arg_count = u30(coder)
                        args = list(reversed(
                            [stack.pop() for _ in range(arg_count)]))
                        obj = stack.pop()
                        if mname == u'reverse':
                            assert isinstance(obj, list)
                            obj.reverse()
                        else:
                            raise NotImplementedError(
                                u'Unsupported (void) property %r on %r'
                                % (mname, obj))
                    elif opcode == 93:  # findpropstrict
                        index = u30(coder)
                        mname = multinames[index]
                        res = extract_function(mname)
                        stack.append(res)
                    elif opcode == 97:  # setproperty
                        index = u30(coder)
                        value = stack.pop()
                        idx = stack.pop()
                        obj = stack.pop()
                        assert isinstance(obj, list)
                        assert isinstance(idx, int)
                        obj[idx] = value
                    elif opcode == 98:  # getlocal
                        index = u30(coder)
                        stack.append(registers[index])
                    elif opcode == 99:  # setlocal
                        index = u30(coder)
                        value = stack.pop()
                        registers[index] = value
                    elif opcode == 102:  # getproperty
                        index = u30(coder)
                        pname = multinames[index]
                        if pname == u'length':
                            obj = stack.pop()
                            assert isinstance(obj, list)
                            stack.append(len(obj))
                        else:  # Assume attribute access
                            idx = stack.pop()
                            assert isinstance(idx, int)
                            obj = stack.pop()
                            assert isinstance(obj, list)
                            stack.append(obj[idx])
                    elif opcode == 128:  # coerce
                        u30(coder)
                    elif opcode == 133:  # coerce_s
                        assert isinstance(stack[-1], (type(None), compat_str))
                    elif opcode == 164:  # modulo
                        value2 = stack.pop()
                        value1 = stack.pop()
                        res = value1 % value2
                        stack.append(res)
                    elif opcode == 208:  # getlocal_0
                        stack.append(registers[0])
                    elif opcode == 209:  # getlocal_1
                        stack.append(registers[1])
                    elif opcode == 210:  # getlocal_2
                        stack.append(registers[2])
                    elif opcode == 211:  # getlocal_3
                        stack.append(registers[3])
                    elif opcode == 214:  # setlocal_2
                        registers[2] = stack.pop()
                    elif opcode == 215:  # setlocal_3
                        registers[3] = stack.pop()
                    else:
                        raise NotImplementedError(
                            u'Unsupported opcode %d' % opcode)

            method_pyfunctions[func_name] = resfunc
            return resfunc

        initial_function = extract_function(u'decipher')
        return lambda s: initial_function([s])

    def _decrypt_signature(self, s, video_id, player_url, age_gate=False):
        """Turn the encrypted s field into a working signature"""

        if player_url is not None:
            if player_url.startswith(u'//'):
                player_url = u'https:' + player_url
            try:
                player_id = (player_url, len(s))
                if player_id not in self._player_cache:
                    func = self._extract_signature_function(
                        video_id, player_url, len(s)
                    )
                    self._player_cache[player_id] = func
                func = self._player_cache[player_id]
                if self._downloader.params.get('youtube_print_sig_code'):
                    self._print_sig_code(func, len(s))
                return func(s)
            except Exception:
                tb = traceback.format_exc()
                self._downloader.report_warning(
                    u'Automatic signature extraction failed: ' + tb)

            self._downloader.report_warning(
                u'Warning: Falling back to static signature algorithm')

        return self._static_decrypt_signature(
            s, video_id, player_url, age_gate)

    def _static_decrypt_signature(self, s, video_id, player_url, age_gate):
        if age_gate:
            # The videos with age protection use another player, so the
            # algorithms can be different.
            if len(s) == 86:
                return s[2:63] + s[82] + s[64:82] + s[63]

        if len(s) == 93:
            return s[86:29:-1] + s[88] + s[28:5:-1]
        elif len(s) == 92:
            return s[25] + s[3:25] + s[0] + s[26:42] + s[79] + s[43:79] + s[91] + s[80:83]
        elif len(s) == 91:
            return s[84:27:-1] + s[86] + s[26:5:-1]
        elif len(s) == 90:
            return s[25] + s[3:25] + s[2] + s[26:40] + s[77] + s[41:77] + s[89] + s[78:81]
        elif len(s) == 89:
            return s[84:78:-1] + s[87] + s[77:60:-1] + s[0] + s[59:3:-1]
        elif len(s) == 88:
            return s[7:28] + s[87] + s[29:45] + s[55] + s[46:55] + s[2] + s[56:87] + s[28]
        elif len(s) == 87:
            return s[6:27] + s[4] + s[28:39] + s[27] + s[40:59] + s[2] + s[60:]
        elif len(s) == 86:
            return s[80:72:-1] + s[16] + s[71:39:-1] + s[72] + s[38:16:-1] + s[82] + s[15::-1]
        elif len(s) == 85:
            return s[3:11] + s[0] + s[12:55] + s[84] + s[56:84]
        elif len(s) == 84:
            return s[78:70:-1] + s[14] + s[69:37:-1] + s[70] + s[36:14:-1] + s[80] + s[:14][::-1]
        elif len(s) == 83:
            return s[80:63:-1] + s[0] + s[62:0:-1] + s[63]
        elif len(s) == 82:
            return s[80:37:-1] + s[7] + s[36:7:-1] + s[0] + s[6:0:-1] + s[37]
        elif len(s) == 81:
            return s[56] + s[79:56:-1] + s[41] + s[55:41:-1] + s[80] + s[40:34:-1] + s[0] + s[33:29:-1] + s[34] + s[28:9:-1] + s[29] + s[8:0:-1] + s[9]
        elif len(s) == 80:
            return s[1:19] + s[0] + s[20:68] + s[19] + s[69:80]
        elif len(s) == 79:
            return s[54] + s[77:54:-1] + s[39] + s[53:39:-1] + s[78] + s[38:34:-1] + s[0] + s[33:29:-1] + s[34] + s[28:9:-1] + s[29] + s[8:0:-1] + s[9]

        else:
            raise ExtractorError(u'Unable to decrypt signature, key length %d not supported; retrying might work' % (len(s)))

    def _get_available_subtitles(self, video_id, webpage):
        try:
            sub_list = self._download_webpage(
                'https://video.google.com/timedtext?hl=en&type=list&v=%s' % video_id,
                video_id, note=False)
        except ExtractorError as err:
            self._downloader.report_warning(u'unable to download video subtitles: %s' % compat_str(err))
            return {}
        lang_list = re.findall(r'name="([^"]*)"[^>]+lang_code="([\w\-]+)"', sub_list)

        sub_lang_list = {}
        for l in lang_list:
            lang = l[1]
            params = compat_urllib_parse.urlencode({
                'lang': lang,
                'v': video_id,
                'fmt': self._downloader.params.get('subtitlesformat', 'srt'),
                'name': unescapeHTML(l[0]).encode('utf-8'),
            })
            url = u'https://www.youtube.com/api/timedtext?' + params
            sub_lang_list[lang] = url
        if not sub_lang_list:
            self._downloader.report_warning(u'video doesn\'t have subtitles')
            return {}
        return sub_lang_list

    def _get_available_automatic_caption(self, video_id, webpage):
        """We need the webpage for getting the captions url, pass it as an
           argument to speed up the process."""
        sub_format = self._downloader.params.get('subtitlesformat', 'srt')
        self.to_screen(u'%s: Looking for automatic captions' % video_id)
        mobj = re.search(r';ytplayer.config = ({.*?});', webpage)
        err_msg = u'Couldn\'t find automatic captions for %s' % video_id
        if mobj is None:
            self._downloader.report_warning(err_msg)
            return {}
        player_config = json.loads(mobj.group(1))
        try:
            args = player_config[u'args']
            caption_url = args[u'ttsurl']
            timestamp = args[u'timestamp']
            # We get the available subtitles
            list_params = compat_urllib_parse.urlencode({
                'type': 'list',
                'tlangs': 1,
                'asrs': 1,
            })
            list_url = caption_url + '&' + list_params
            caption_list = self._download_xml(list_url, video_id)
            original_lang_node = caption_list.find('track')
            if original_lang_node is None or original_lang_node.attrib.get('kind') != 'asr' :
                self._downloader.report_warning(u'Video doesn\'t have automatic captions')
                return {}
            original_lang = original_lang_node.attrib['lang_code']

            sub_lang_list = {}
            for lang_node in caption_list.findall('target'):
                sub_lang = lang_node.attrib['lang_code']
                params = compat_urllib_parse.urlencode({
                    'lang': original_lang,
                    'tlang': sub_lang,
                    'fmt': sub_format,
                    'ts': timestamp,
                    'kind': 'asr',
                })
                sub_lang_list[sub_lang] = caption_url + '&' + params
            return sub_lang_list
        # An extractor error can be raise by the download process if there are
        # no automatic captions but there are subtitles
        except (KeyError, ExtractorError):
            self._downloader.report_warning(err_msg)
            return {}

    @classmethod
    def extract_id(cls, url):
        mobj = re.match(cls._VALID_URL, url, re.VERBOSE)
        if mobj is None:
            raise ExtractorError(u'Invalid URL: %s' % url)
        video_id = mobj.group(2)
        return video_id

    def _extract_from_m3u8(self, manifest_url, video_id):
        url_map = {}
        def _get_urls(_manifest):
            lines = _manifest.split('\n')
            urls = filter(lambda l: l and not l.startswith('#'),
                            lines)
            return urls
        manifest = self._download_webpage(manifest_url, video_id, u'Downloading formats manifest')
        formats_urls = _get_urls(manifest)
        for format_url in formats_urls:
            itag = self._search_regex(r'itag/(\d+?)/', format_url, 'itag')
            url_map[itag] = format_url
        return url_map

    def _extract_annotations(self, video_id):
        url = 'https://www.youtube.com/annotations_invideo?features=1&legacy=1&video_id=%s' % video_id
        return self._download_webpage(url, video_id, note=u'Searching for annotations.', errnote=u'Unable to download video annotations.')

    def _real_extract(self, url):
        proto = (
            u'http' if self._downloader.params.get('prefer_insecure', False)
            else u'https')

        # Extract original video URL from URL with redirection, like age verification, using next_url parameter
        mobj = re.search(self._NEXT_URL_RE, url)
        if mobj:
            url = proto + '://www.youtube.com/' + compat_urllib_parse.unquote(mobj.group(1)).lstrip('/')
        video_id = self.extract_id(url)

        # Get video webpage
        url = proto + '://www.youtube.com/watch?v=%s&gl=US&hl=en&has_verified=1' % video_id
        video_webpage = self._download_webpage(url, video_id)

        # Attempt to extract SWF player URL
        mobj = re.search(r'swfConfig.*?"(https?:\\/\\/.*?watch.*?-.*?\.swf)"', video_webpage)
        if mobj is not None:
            player_url = re.sub(r'\\(.)', r'\1', mobj.group(1))
        else:
            player_url = None

        # Get video info
        self.report_video_info_webpage_download(video_id)
        if re.search(r'player-age-gate-content">', video_webpage) is not None:
            self.report_age_confirmation()
            age_gate = True
            # We simulate the access to the video from www.youtube.com/v/{video_id}
            # this can be viewed without login into Youtube
            data = compat_urllib_parse.urlencode({'video_id': video_id,
                                                  'el': 'player_embedded',
                                                  'gl': 'US',
                                                  'hl': 'en',
                                                  'eurl': 'https://youtube.googleapis.com/v/' + video_id,
                                                  'asv': 3,
                                                  'sts':'1588',
                                                  })
            video_info_url = proto + '://www.youtube.com/get_video_info?' + data
            video_info_webpage = self._download_webpage(video_info_url, video_id,
                                    note=False,
                                    errnote='unable to download video info webpage')
            video_info = compat_parse_qs(video_info_webpage)
        else:
            age_gate = False
            for el_type in ['&el=embedded', '&el=detailpage', '&el=vevo', '']:
                video_info_url = (proto + '://www.youtube.com/get_video_info?&video_id=%s%s&ps=default&eurl=&gl=US&hl=en'
                        % (video_id, el_type))
                video_info_webpage = self._download_webpage(video_info_url, video_id,
                                        note=False,
                                        errnote='unable to download video info webpage')
                video_info = compat_parse_qs(video_info_webpage)
                if 'token' in video_info:
                    break
        if 'token' not in video_info:
            if 'reason' in video_info:
                raise ExtractorError(u'YouTube said: %s' % video_info['reason'][0], expected=True)
            else:
                raise ExtractorError(u'"token" parameter not in video info for unknown reason')

        if 'view_count' in video_info:
            view_count = int(video_info['view_count'][0])
        else:
            view_count = None

        # Check for "rental" videos
        if 'ypc_video_rental_bar_text' in video_info and 'author' not in video_info:
            raise ExtractorError(u'"rental" videos not supported')

        # Start extracting information
        self.report_information_extraction(video_id)

        # uploader
        if 'author' not in video_info:
            raise ExtractorError(u'Unable to extract uploader name')
        video_uploader = compat_urllib_parse.unquote_plus(video_info['author'][0])

        # uploader_id
        video_uploader_id = None
        mobj = re.search(r'<link itemprop="url" href="http://www.youtube.com/(?:user|channel)/([^"]+)">', video_webpage)
        if mobj is not None:
            video_uploader_id = mobj.group(1)
        else:
            self._downloader.report_warning(u'unable to extract uploader nickname')

        # title
        if 'title' in video_info:
            video_title = compat_urllib_parse.unquote_plus(video_info['title'][0])
        else:
            self._downloader.report_warning(u'Unable to extract video title')
            video_title = u'_'

        # thumbnail image
        # We try first to get a high quality image:
        m_thumb = re.search(r'<span itemprop="thumbnail".*?href="(.*?)">',
                            video_webpage, re.DOTALL)
        if m_thumb is not None:
            video_thumbnail = m_thumb.group(1)
        elif 'thumbnail_url' not in video_info:
            self._downloader.report_warning(u'unable to extract video thumbnail')
            video_thumbnail = None
        else:   # don't panic if we can't find it
            video_thumbnail = compat_urllib_parse.unquote_plus(video_info['thumbnail_url'][0])

        # upload date
        upload_date = None
        mobj = re.search(r'id="eow-date.*?>(.*?)</span>', video_webpage, re.DOTALL)
        if mobj is not None:
            upload_date = ' '.join(re.sub(r'[/,-]', r' ', mobj.group(1)).split())
            upload_date = unified_strdate(upload_date)

        # description
        video_description = get_element_by_id("eow-description", video_webpage)
        if video_description:
            video_description = re.sub(r'''(?x)
                <a\s+
                    (?:[a-zA-Z-]+="[^"]+"\s+)*?
                    title="([^"]+)"\s+
                    (?:[a-zA-Z-]+="[^"]+"\s+)*?
                    class="yt-uix-redirect-link"\s*>
                [^<]+
                </a>
            ''', r'\1', video_description)
            video_description = clean_html(video_description)
        else:
            fd_mobj = re.search(r'<meta name="description" content="([^"]+)"', video_webpage)
            if fd_mobj:
                video_description = unescapeHTML(fd_mobj.group(1))
            else:
                video_description = u''

        def _extract_count(klass):
            count = self._search_regex(
                r'class="%s">([\d,]+)</span>' % re.escape(klass),
                video_webpage, klass, default=None)
            if count is not None:
                return int(count.replace(',', ''))
            return None
        like_count = _extract_count(u'likes-count')
        dislike_count = _extract_count(u'dislikes-count')

        # subtitles
        video_subtitles = self.extract_subtitles(video_id, video_webpage)

        if self._downloader.params.get('listsubtitles', False):
            self._list_available_subtitles(video_id, video_webpage)
            return

        if 'length_seconds' not in video_info:
            self._downloader.report_warning(u'unable to extract video duration')
            video_duration = None
        else:
            video_duration = int(compat_urllib_parse.unquote_plus(video_info['length_seconds'][0]))

        # annotations
        video_annotations = None
        if self._downloader.params.get('writeannotations', False):
                video_annotations = self._extract_annotations(video_id)

        # Decide which formats to download
        try:
            mobj = re.search(r';ytplayer\.config\s*=\s*({.*?});', video_webpage)
            if not mobj:
                raise ValueError('Could not find vevo ID')
            json_code = uppercase_escape(mobj.group(1))
            ytplayer_config = json.loads(json_code)
            args = ytplayer_config['args']
            # Easy way to know if the 's' value is in url_encoded_fmt_stream_map
            # this signatures are encrypted
            if 'url_encoded_fmt_stream_map' not in args:
                raise ValueError(u'No stream_map present')  # caught below
            re_signature = re.compile(r'[&,]s=')
            m_s = re_signature.search(args['url_encoded_fmt_stream_map'])
            if m_s is not None:
                self.to_screen(u'%s: Encrypted signatures detected.' % video_id)
                video_info['url_encoded_fmt_stream_map'] = [args['url_encoded_fmt_stream_map']]
            m_s = re_signature.search(args.get('adaptive_fmts', u''))
            if m_s is not None:
                if 'adaptive_fmts' in video_info:
                    video_info['adaptive_fmts'][0] += ',' + args['adaptive_fmts']
                else:
                    video_info['adaptive_fmts'] = [args['adaptive_fmts']]
        except ValueError:
            pass

        def _map_to_format_list(urlmap):
            formats = []
            for itag, video_real_url in urlmap.items():
                dct = {
                    'format_id': itag,
                    'url': video_real_url,
                    'player_url': player_url,
                }
                if itag in self._formats:
                    dct.update(self._formats[itag])
                formats.append(dct)
            return formats

        if 'conn' in video_info and video_info['conn'][0].startswith('rtmp'):
            self.report_rtmp_download()
            formats = [{
                'format_id': '_rtmp',
                'protocol': 'rtmp',
                'url': video_info['conn'][0],
                'player_url': player_url,
            }]
        elif len(video_info.get('url_encoded_fmt_stream_map', [])) >= 1 or len(video_info.get('adaptive_fmts', [])) >= 1:
            encoded_url_map = video_info.get('url_encoded_fmt_stream_map', [''])[0] + ',' + video_info.get('adaptive_fmts',[''])[0]
            if 'rtmpe%3Dyes' in encoded_url_map:
                raise ExtractorError('rtmpe downloads are not supported, see https://github.com/rg3/youtube-dl/issues/343 for more information.', expected=True)
            url_map = {}
            for url_data_str in encoded_url_map.split(','):
                url_data = compat_parse_qs(url_data_str)
                if 'itag' in url_data and 'url' in url_data:
                    url = url_data['url'][0]
                    if 'sig' in url_data:
                        url += '&signature=' + url_data['sig'][0]
                    elif 's' in url_data:
                        encrypted_sig = url_data['s'][0]
                        if self._downloader.params.get('verbose'):
                            if age_gate:
                                if player_url is None:
                                    player_version = 'unknown'
                                else:
                                    player_version = self._search_regex(
                                        r'-(.+)\.swf$', player_url,
                                        u'flash player', fatal=False)
                                player_desc = 'flash player %s' % player_version
                            else:
                                player_version = self._search_regex(
                                    r'html5player-(.+?)\.js', video_webpage,
                                    'html5 player', fatal=False)
                                player_desc = u'html5 player %s' % player_version

                            parts_sizes = u'.'.join(compat_str(len(part)) for part in encrypted_sig.split('.'))
                            self.to_screen(u'encrypted signature length %d (%s), itag %s, %s' %
                                (len(encrypted_sig), parts_sizes, url_data['itag'][0], player_desc))

                        if not age_gate:
                            jsplayer_url_json = self._search_regex(
                                r'"assets":.+?"js":\s*("[^"]+")',
                                video_webpage, u'JS player URL')
                            player_url = json.loads(jsplayer_url_json)

                        signature = self._decrypt_signature(
                            encrypted_sig, video_id, player_url, age_gate)
                        url += '&signature=' + signature
                    if 'ratebypass' not in url:
                        url += '&ratebypass=yes'
                    url_map[url_data['itag'][0]] = url
            formats = _map_to_format_list(url_map)
        elif video_info.get('hlsvp'):
            manifest_url = video_info['hlsvp'][0]
            url_map = self._extract_from_m3u8(manifest_url, video_id)
            formats = _map_to_format_list(url_map)
        else:
            raise ExtractorError(u'no conn, hlsvp or url_encoded_fmt_stream_map information found in video info')

        # Look for the DASH manifest
        if (self._downloader.params.get('youtube_include_dash_manifest', False)):
            try:
                # The DASH manifest used needs to be the one from the original video_webpage.
                # The one found in get_video_info seems to be using different signatures.
                # However, in the case of an age restriction there won't be any embedded dashmpd in the video_webpage.
                # Luckily, it seems, this case uses some kind of default signature (len == 86), so the
                # combination of get_video_info and the _static_decrypt_signature() decryption fallback will work here.
                if age_gate:
                    dash_manifest_url = video_info.get('dashmpd')[0]
                else:
                    dash_manifest_url = ytplayer_config['args']['dashmpd']
                def decrypt_sig(mobj):
                    s = mobj.group(1)
                    dec_s = self._decrypt_signature(s, video_id, player_url, age_gate)
                    return '/signature/%s' % dec_s
                dash_manifest_url = re.sub(r'/s/([\w\.]+)', decrypt_sig, dash_manifest_url)
                dash_doc = self._download_xml(
                    dash_manifest_url, video_id,
                    note=u'Downloading DASH manifest',
                    errnote=u'Could not download DASH manifest')
                for r in dash_doc.findall(u'.//{urn:mpeg:DASH:schema:MPD:2011}Representation'):
                    url_el = r.find('{urn:mpeg:DASH:schema:MPD:2011}BaseURL')
                    if url_el is None:
                        continue
                    format_id = r.attrib['id']
                    video_url = url_el.text
                    filesize = int_or_none(url_el.attrib.get('{http://youtube.com/yt/2012/10/10}contentLength'))
                    f = {
                        'format_id': format_id,
                        'url': video_url,
                        'width': int_or_none(r.attrib.get('width')),
                        'tbr': int_or_none(r.attrib.get('bandwidth'), 1000),
                        'asr': int_or_none(r.attrib.get('audioSamplingRate')),
                        'filesize': filesize,
                    }
                    try:
                        existing_format = next(
                            fo for fo in formats
                            if fo['format_id'] == format_id)
                    except StopIteration:
                        f.update(self._formats.get(format_id, {}))
                        formats.append(f)
                    else:
                        existing_format.update(f)

            except (ExtractorError, KeyError) as e:
                self.report_warning(u'Skipping DASH manifest: %s' % e, video_id)

        self._sort_formats(formats)

        return {
            'id':           video_id,
            'uploader':     video_uploader,
            'uploader_id':  video_uploader_id,
            'upload_date':  upload_date,
            'title':        video_title,
            'thumbnail':    video_thumbnail,
            'description':  video_description,
            'subtitles':    video_subtitles,
            'duration':     video_duration,
            'age_limit':    18 if age_gate else 0,
            'annotations':  video_annotations,
            'webpage_url': proto + '://www.youtube.com/watch?v=%s' % video_id,
            'view_count':   view_count,
            'like_count': like_count,
            'dislike_count': dislike_count,
            'formats':      formats,
        }

class YoutubePlaylistIE(YoutubeBaseInfoExtractor):
    IE_DESC = u'YouTube.com playlists'
    _VALID_URL = r"""(?x)(?:
                        (?:https?://)?
                        (?:\w+\.)?
                        youtube\.com/
                        (?:
                           (?:course|view_play_list|my_playlists|artist|playlist|watch)
                           \? (?:.*?&)*? (?:p|a|list)=
                        |  p/
                        )
                        (
                            (?:PL|EC|UU|FL|RD)?[0-9A-Za-z-_]{10,}
                            # Top tracks, they can also include dots 
                            |(?:MC)[\w\.]*
                        )
                        .*
                     |
                        ((?:PL|EC|UU|FL|RD)[0-9A-Za-z-_]{10,})
                     )"""
    _TEMPLATE_URL = 'https://www.youtube.com/playlist?list=%s'
    _MORE_PAGES_INDICATOR = r'data-link-type="next"'
    _VIDEO_RE = r'href="\s*/watch\?v=(?P<id>[0-9A-Za-z_-]{11})&amp;[^"]*?index=(?P<index>\d+)'
    IE_NAME = u'youtube:playlist'

    def _real_initialize(self):
        self._login()

    def _ids_to_results(self, ids):
        return [self.url_result(vid_id, 'Youtube', video_id=vid_id)
                       for vid_id in ids]

    def _extract_mix(self, playlist_id):
        # The mixes are generated from a a single video
        # the id of the playlist is just 'RD' + video_id
        url = 'https://youtube.com/watch?v=%s&list=%s' % (playlist_id[-11:], playlist_id)
        webpage = self._download_webpage(url, playlist_id, u'Downloading Youtube mix')
        search_title = lambda class_name: get_element_by_attribute('class', class_name, webpage)
        title_span = (search_title('playlist-title') or
            search_title('title long-title') or search_title('title'))
        title = clean_html(title_span)
        video_re = r'''(?x)data-video-username="(.*?)".*?
                       href="/watch\?v=([0-9A-Za-z_-]{11})&amp;[^"]*?list=%s''' % re.escape(playlist_id)
        matches = orderedSet(re.findall(video_re, webpage, flags=re.DOTALL))
        # Some of the videos may have been deleted, their username field is empty
        ids = [video_id for (username, video_id) in matches if username]
        url_results = self._ids_to_results(ids)

        return self.playlist_result(url_results, playlist_id, title)

    def _real_extract(self, url):
        # Extract playlist id
        mobj = re.match(self._VALID_URL, url)
        if mobj is None:
            raise ExtractorError(u'Invalid URL: %s' % url)
        playlist_id = mobj.group(1) or mobj.group(2)

        # Check if it's a video-specific URL
        query_dict = compat_urlparse.parse_qs(compat_urlparse.urlparse(url).query)
        if 'v' in query_dict:
            video_id = query_dict['v'][0]
            if self._downloader.params.get('noplaylist'):
                self.to_screen(u'Downloading just video %s because of --no-playlist' % video_id)
                return self.url_result(video_id, 'Youtube', video_id=video_id)
            else:
                self.to_screen(u'Downloading playlist PL%s - add --no-playlist to just download video %s' % (playlist_id, video_id))

        if playlist_id.startswith('RD'):
            # Mixes require a custom extraction process
            return self._extract_mix(playlist_id)
        if playlist_id.startswith('TL'):
            raise ExtractorError(u'For downloading YouTube.com top lists, use '
                u'the "yttoplist" keyword, for example "youtube-dl \'yttoplist:music:Top Tracks\'"', expected=True)

        url = self._TEMPLATE_URL % playlist_id
        page = self._download_webpage(url, playlist_id)
        more_widget_html = content_html = page

        # Extract the video ids from the playlist pages
        ids = []

        for page_num in itertools.count(1):
            matches = re.finditer(self._VIDEO_RE, content_html)
            # We remove the duplicates and the link with index 0
            # (it's not the first video of the playlist)
            new_ids = orderedSet(m.group('id') for m in matches if m.group('index') != '0')
            ids.extend(new_ids)

            mobj = re.search(r'data-uix-load-more-href="/?(?P<more>[^"]+)"', more_widget_html)
            if not mobj:
                break

            more = self._download_json(
                'https://youtube.com/%s' % mobj.group('more'), playlist_id, 'Downloading page #%s' % page_num)
            content_html = more['content_html']
            more_widget_html = more['load_more_widget_html']

        playlist_title = self._html_search_regex(
                r'<h1 class="pl-header-title">\s*(.*?)\s*</h1>', page, u'title')

        url_results = self._ids_to_results(ids)
        return self.playlist_result(url_results, playlist_id, playlist_title)


class YoutubeTopListIE(YoutubePlaylistIE):
    IE_NAME = u'youtube:toplist'
    IE_DESC = (u'YouTube.com top lists, "yttoplist:{channel}:{list title}"'
        u' (Example: "yttoplist:music:Top Tracks")')
    _VALID_URL = r'yttoplist:(?P<chann>.*?):(?P<title>.*?)$'

    def _real_extract(self, url):
        mobj = re.match(self._VALID_URL, url)
        channel = mobj.group('chann')
        title = mobj.group('title')
        query = compat_urllib_parse.urlencode({'title': title})
        playlist_re = 'href="([^"]+?%s.*?)"' % re.escape(query)
        channel_page = self._download_webpage('https://www.youtube.com/%s' % channel, title)
        link = self._html_search_regex(playlist_re, channel_page, u'list')
        url = compat_urlparse.urljoin('https://www.youtube.com/', link)
        
        video_re = r'data-index="\d+".*?data-video-id="([0-9A-Za-z_-]{11})"'
        ids = []
        # sometimes the webpage doesn't contain the videos
        # retry until we get them
        for i in itertools.count(0):
            msg = u'Downloading Youtube mix'
            if i > 0:
                msg += ', retry #%d' % i
            webpage = self._download_webpage(url, title, msg)
            ids = orderedSet(re.findall(video_re, webpage))
            if ids:
                break
        url_results = self._ids_to_results(ids)
        return self.playlist_result(url_results, playlist_title=title)


class YoutubeChannelIE(InfoExtractor):
    IE_DESC = u'YouTube.com channels'
    _VALID_URL = r"^(?:https?://)?(?:youtu\.be|(?:\w+\.)?youtube(?:-nocookie)?\.com)/channel/([0-9A-Za-z_-]+)"
    _MORE_PAGES_INDICATOR = 'yt-uix-load-more'
    _MORE_PAGES_URL = 'https://www.youtube.com/c4_browse_ajax?action_load_more_videos=1&flow=list&paging=%s&view=0&sort=da&channel_id=%s'
    IE_NAME = u'youtube:channel'

    def extract_videos_from_page(self, page):
        ids_in_page = []
        for mobj in re.finditer(r'href="/watch\?v=([0-9A-Za-z_-]+)&?', page):
            if mobj.group(1) not in ids_in_page:
                ids_in_page.append(mobj.group(1))
        return ids_in_page

    def _real_extract(self, url):
        # Extract channel id
        mobj = re.match(self._VALID_URL, url)
        if mobj is None:
            raise ExtractorError(u'Invalid URL: %s' % url)

        # Download channel page
        channel_id = mobj.group(1)
        video_ids = []
        url = 'https://www.youtube.com/channel/%s/videos' % channel_id
        channel_page = self._download_webpage(url, channel_id)
        autogenerated = re.search(r'''(?x)
                class="[^"]*?(?:
                    channel-header-autogenerated-label|
                    yt-channel-title-autogenerated
                )[^"]*"''', channel_page) is not None

        if autogenerated:
            # The videos are contained in a single page
            # the ajax pages can't be used, they are empty
            video_ids = self.extract_videos_from_page(channel_page)
        else:
            # Download all channel pages using the json-based channel_ajax query
            for pagenum in itertools.count(1):
                url = self._MORE_PAGES_URL % (pagenum, channel_id)
                page = self._download_json(
                    url, channel_id, note=u'Downloading page #%s' % pagenum,
                    transform_source=uppercase_escape)

                ids_in_page = self.extract_videos_from_page(page['content_html'])
                video_ids.extend(ids_in_page)
    
                if self._MORE_PAGES_INDICATOR not in page['load_more_widget_html']:
                    break

        self._downloader.to_screen(u'[youtube] Channel %s: Found %i videos' % (channel_id, len(video_ids)))

        url_entries = [self.url_result(video_id, 'Youtube', video_id=video_id)
                       for video_id in video_ids]
        return self.playlist_result(url_entries, channel_id)


class YoutubeUserIE(InfoExtractor):
    IE_DESC = u'YouTube.com user videos (URL or "ytuser" keyword)'
    _VALID_URL = r'(?:(?:(?:https?://)?(?:\w+\.)?youtube\.com/(?:user/)?(?!(?:attribution_link|watch|results)(?:$|[^a-z_A-Z0-9-])))|ytuser:)(?!feed/)([A-Za-z0-9_-]+)'
    _TEMPLATE_URL = 'https://gdata.youtube.com/feeds/api/users/%s'
    _GDATA_PAGE_SIZE = 50
    _GDATA_URL = 'https://gdata.youtube.com/feeds/api/users/%s/uploads?max-results=%d&start-index=%d&alt=json'
    IE_NAME = u'youtube:user'

    @classmethod
    def suitable(cls, url):
        # Don't return True if the url can be extracted with other youtube
        # extractor, the regex would is too permissive and it would match.
        other_ies = iter(klass for (name, klass) in globals().items() if name.endswith('IE') and klass is not cls)
        if any(ie.suitable(url) for ie in other_ies): return False
        else: return super(YoutubeUserIE, cls).suitable(url)

    def _real_extract(self, url):
        # Extract username
        mobj = re.match(self._VALID_URL, url)
        if mobj is None:
            raise ExtractorError(u'Invalid URL: %s' % url)

        username = mobj.group(1)

        # Download video ids using YouTube Data API. Result size per
        # query is limited (currently to 50 videos) so we need to query
        # page by page until there are no video ids - it means we got
        # all of them.

        def download_page(pagenum):
            start_index = pagenum * self._GDATA_PAGE_SIZE + 1

            gdata_url = self._GDATA_URL % (username, self._GDATA_PAGE_SIZE, start_index)
            page = self._download_webpage(
                gdata_url, username,
                u'Downloading video ids from %d to %d' % (
                    start_index, start_index + self._GDATA_PAGE_SIZE))

            try:
                response = json.loads(page)
            except ValueError as err:
                raise ExtractorError(u'Invalid JSON in API response: ' + compat_str(err))
            if 'entry' not in response['feed']:
                return

            # Extract video identifiers
            entries = response['feed']['entry']
            for entry in entries:
                title = entry['title']['$t']
                video_id = entry['id']['$t'].split('/')[-1]
                yield {
                    '_type': 'url',
                    'url': video_id,
                    'ie_key': 'Youtube',
                    'id': video_id,
                    'title': title,
                }
        url_results = PagedList(download_page, self._GDATA_PAGE_SIZE)

        return self.playlist_result(url_results, playlist_title=username)


class YoutubeSearchIE(SearchInfoExtractor):
    IE_DESC = u'YouTube.com searches'
    _API_URL = u'https://gdata.youtube.com/feeds/api/videos?q=%s&start-index=%i&max-results=50&v=2&alt=jsonc'
    _MAX_RESULTS = 1000
    IE_NAME = u'youtube:search'
    _SEARCH_KEY = 'ytsearch'

    def _get_n_results(self, query, n):
        """Get a specified number of results for a query"""

        video_ids = []
        pagenum = 0
        limit = n
        PAGE_SIZE = 50

        while (PAGE_SIZE * pagenum) < limit:
            result_url = self._API_URL % (
                compat_urllib_parse.quote_plus(query.encode('utf-8')),
                (PAGE_SIZE * pagenum) + 1)
            data_json = self._download_webpage(
                result_url, video_id=u'query "%s"' % query,
                note=u'Downloading page %s' % (pagenum + 1),
                errnote=u'Unable to download API page')
            data = json.loads(data_json)
            api_response = data['data']

            if 'items' not in api_response:
                raise ExtractorError(
                    u'[youtube] No video results', expected=True)

            new_ids = list(video['id'] for video in api_response['items'])
            video_ids += new_ids

            limit = min(n, api_response['totalItems'])
            pagenum += 1

        if len(video_ids) > n:
            video_ids = video_ids[:n]
        videos = [self.url_result(video_id, 'Youtube', video_id=video_id)
                  for video_id in video_ids]
        return self.playlist_result(videos, query)


class YoutubeSearchDateIE(YoutubeSearchIE):
    IE_NAME = YoutubeSearchIE.IE_NAME + ':date'
    _API_URL = 'https://gdata.youtube.com/feeds/api/videos?q=%s&start-index=%i&max-results=50&v=2&alt=jsonc&orderby=published'
    _SEARCH_KEY = 'ytsearchdate'
    IE_DESC = u'YouTube.com searches, newest videos first'


class YoutubeSearchURLIE(InfoExtractor):
    IE_DESC = u'YouTube.com search URLs'
    IE_NAME = u'youtube:search_url'
    _VALID_URL = r'https?://(?:www\.)?youtube\.com/results\?(.*?&)?search_query=(?P<query>[^&]+)(?:[&]|$)'

    def _real_extract(self, url):
        mobj = re.match(self._VALID_URL, url)
        query = compat_urllib_parse.unquote_plus(mobj.group('query'))

        webpage = self._download_webpage(url, query)
        result_code = self._search_regex(
            r'(?s)<ol id="search-results"(.*?)</ol>', webpage, u'result HTML')

        part_codes = re.findall(
            r'(?s)<h3 class="yt-lockup-title">(.*?)</h3>', result_code)
        entries = []
        for part_code in part_codes:
            part_title = self._html_search_regex(
                r'(?s)title="([^"]+)"', part_code, 'item title', fatal=False)
            part_url_snippet = self._html_search_regex(
                r'(?s)href="([^"]+)"', part_code, 'item URL')
            part_url = compat_urlparse.urljoin(
                'https://www.youtube.com/', part_url_snippet)
            entries.append({
                '_type': 'url',
                'url': part_url,
                'title': part_title,
            })

        return {
            '_type': 'playlist',
            'entries': entries,
            'title': query,
        }


class YoutubeShowIE(InfoExtractor):
    IE_DESC = u'YouTube.com (multi-season) shows'
    _VALID_URL = r'https?://www\.youtube\.com/show/(.*)'
    IE_NAME = u'youtube:show'

    def _real_extract(self, url):
        mobj = re.match(self._VALID_URL, url)
        show_name = mobj.group(1)
        webpage = self._download_webpage(url, show_name, u'Downloading show webpage')
        # There's one playlist for each season of the show
        m_seasons = list(re.finditer(r'href="(/playlist\?list=.*?)"', webpage))
        self.to_screen(u'%s: Found %s seasons' % (show_name, len(m_seasons)))
        return [self.url_result('https://www.youtube.com' + season.group(1), 'YoutubePlaylist') for season in m_seasons]


class YoutubeFeedsInfoExtractor(YoutubeBaseInfoExtractor):
    """
    Base class for extractors that fetch info from
    http://www.youtube.com/feed_ajax
    Subclasses must define the _FEED_NAME and _PLAYLIST_TITLE properties.
    """
    _LOGIN_REQUIRED = True
    # use action_load_personal_feed instead of action_load_system_feed
    _PERSONAL_FEED = False

    @property
    def _FEED_TEMPLATE(self):
        action = 'action_load_system_feed'
        if self._PERSONAL_FEED:
            action = 'action_load_personal_feed'
        return 'https://www.youtube.com/feed_ajax?%s=1&feed_name=%s&paging=%%s' % (action, self._FEED_NAME)

    @property
    def IE_NAME(self):
        return u'youtube:%s' % self._FEED_NAME

    def _real_initialize(self):
        self._login()

    def _real_extract(self, url):
        feed_entries = []
        paging = 0
        for i in itertools.count(1):
            info = self._download_webpage(self._FEED_TEMPLATE % paging,
                                          u'%s feed' % self._FEED_NAME,
                                          u'Downloading page %s' % i)
            info = json.loads(info)
            feed_html = info['feed_html']
            m_ids = re.finditer(r'"/watch\?v=(.*?)["&]', feed_html)
            ids = orderedSet(m.group(1) for m in m_ids)
            feed_entries.extend(
                self.url_result(video_id, 'Youtube', video_id=video_id)
                for video_id in ids)
            if info['paging'] is None:
                break
            paging = info['paging']
        return self.playlist_result(feed_entries, playlist_title=self._PLAYLIST_TITLE)

class YoutubeSubscriptionsIE(YoutubeFeedsInfoExtractor):
    IE_DESC = u'YouTube.com subscriptions feed, "ytsubs" keyword(requires authentication)'
    _VALID_URL = r'https?://www\.youtube\.com/feed/subscriptions|:ytsubs(?:criptions)?'
    _FEED_NAME = 'subscriptions'
    _PLAYLIST_TITLE = u'Youtube Subscriptions'

class YoutubeRecommendedIE(YoutubeFeedsInfoExtractor):
    IE_DESC = u'YouTube.com recommended videos, "ytrec" keyword (requires authentication)'
    _VALID_URL = r'https?://www\.youtube\.com/feed/recommended|:ytrec(?:ommended)?'
    _FEED_NAME = 'recommended'
    _PLAYLIST_TITLE = u'Youtube Recommended videos'

class YoutubeWatchLaterIE(YoutubeFeedsInfoExtractor):
    IE_DESC = u'Youtube watch later list, "ytwatchlater" keyword (requires authentication)'
    _VALID_URL = r'https?://www\.youtube\.com/feed/watch_later|:ytwatchlater'
    _FEED_NAME = 'watch_later'
    _PLAYLIST_TITLE = u'Youtube Watch Later'
    _PERSONAL_FEED = True

class YoutubeHistoryIE(YoutubeFeedsInfoExtractor):
    IE_DESC = u'Youtube watch history, "ythistory" keyword (requires authentication)'
    _VALID_URL = u'https?://www\.youtube\.com/feed/history|:ythistory'
    _FEED_NAME = 'history'
    _PERSONAL_FEED = True
    _PLAYLIST_TITLE = u'Youtube Watch History'

class YoutubeFavouritesIE(YoutubeBaseInfoExtractor):
    IE_NAME = u'youtube:favorites'
    IE_DESC = u'YouTube.com favourite videos, "ytfav" keyword (requires authentication)'
    _VALID_URL = r'https?://www\.youtube\.com/my_favorites|:ytfav(?:ou?rites)?'
    _LOGIN_REQUIRED = True

    def _real_extract(self, url):
        webpage = self._download_webpage('https://www.youtube.com/my_favorites', 'Youtube Favourites videos')
        playlist_id = self._search_regex(r'list=(.+?)["&]', webpage, u'favourites playlist id')
        return self.url_result(playlist_id, 'YoutubePlaylist')


class YoutubeTruncatedURLIE(InfoExtractor):
    IE_NAME = 'youtube:truncated_url'
    IE_DESC = False  # Do not list
    _VALID_URL = r'''(?x)
        (?:https?://)?[^/]+/watch\?(?:feature=[a-z_]+)?$|
        (?:https?://)?(?:www\.)?youtube\.com/attribution_link\?a=[^&]+$
    '''

    def _real_extract(self, url):
        raise ExtractorError(
            u'Did you forget to quote the URL? Remember that & is a meta '
            u'character in most shells, so you want to put the URL in quotes, '
            u'like  youtube-dl '
            u'"http://www.youtube.com/watch?feature=foo&v=BaW_jenozKc" '
            u' or simply  youtube-dl BaW_jenozKc  .',
            expected=True)