File size: 71,861 Bytes
fe41391
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# TODO:
# * Documentation -- this will need a new section of the User's Guide.
#      Both for Animations and just timers.
#   - Also need to update
#     https://scipy-cookbook.readthedocs.io/items/Matplotlib_Animations.html
# * Blit
#   * Currently broken with Qt4 for widgets that don't start on screen
#   * Still a few edge cases that aren't working correctly
#   * Can this integrate better with existing matplotlib animation artist flag?
#     - If animated removes from default draw(), perhaps we could use this to
#       simplify initial draw.
# * Example
#   * Frameless animation - pure procedural with no loop
#   * Need example that uses something like inotify or subprocess
#   * Complex syncing examples
# * Movies
#   * Can blit be enabled for movies?
# * Need to consider event sources to allow clicking through multiple figures


import abc
import base64
import contextlib
from io import BytesIO, TextIOWrapper
import itertools
import logging
from pathlib import Path
import shutil
import subprocess
import sys
from tempfile import TemporaryDirectory
import uuid
import warnings

import numpy as np
from PIL import Image

import matplotlib as mpl
from matplotlib._animation_data import (
    DISPLAY_TEMPLATE, INCLUDED_FRAMES, JS_INCLUDE, STYLE_INCLUDE)
from matplotlib import _api, cbook
import matplotlib.colors as mcolors

_log = logging.getLogger(__name__)

# Process creation flag for subprocess to prevent it raising a terminal
# window. See for example https://stackoverflow.com/q/24130623/
subprocess_creation_flags = (
    subprocess.CREATE_NO_WINDOW if sys.platform == 'win32' else 0)

# Other potential writing methods:
# * http://pymedia.org/
# * libming (produces swf) python wrappers: https://github.com/libming/libming
# * Wrap x264 API:

# (https://stackoverflow.com/q/2940671/)


def adjusted_figsize(w, h, dpi, n):
    """
    Compute figure size so that pixels are a multiple of n.

    Parameters
    ----------
    w, h : float
        Size in inches.

    dpi : float
        The dpi.

    n : int
        The target multiple.

    Returns
    -------
    wnew, hnew : float
        The new figure size in inches.
    """

    # this maybe simplified if / when we adopt consistent rounding for
    # pixel size across the whole library
    def correct_roundoff(x, dpi, n):
        if int(x*dpi) % n != 0:
            if int(np.nextafter(x, np.inf)*dpi) % n == 0:
                x = np.nextafter(x, np.inf)
            elif int(np.nextafter(x, -np.inf)*dpi) % n == 0:
                x = np.nextafter(x, -np.inf)
        return x

    wnew = int(w * dpi / n) * n / dpi
    hnew = int(h * dpi / n) * n / dpi
    return correct_roundoff(wnew, dpi, n), correct_roundoff(hnew, dpi, n)


class MovieWriterRegistry:
    """Registry of available writer classes by human readable name."""

    def __init__(self):
        self._registered = dict()

    def register(self, name):
        """
        Decorator for registering a class under a name.

        Example use::

            @registry.register(name)
            class Foo:
                pass
        """
        def wrapper(writer_cls):
            self._registered[name] = writer_cls
            return writer_cls
        return wrapper

    def is_available(self, name):
        """
        Check if given writer is available by name.

        Parameters
        ----------
        name : str

        Returns
        -------
        bool
        """
        try:
            cls = self._registered[name]
        except KeyError:
            return False
        return cls.isAvailable()

    def __iter__(self):
        """Iterate over names of available writer class."""
        for name in self._registered:
            if self.is_available(name):
                yield name

    def list(self):
        """Get a list of available MovieWriters."""
        return [*self]

    def __getitem__(self, name):
        """Get an available writer class from its name."""
        if self.is_available(name):
            return self._registered[name]
        raise RuntimeError(f"Requested MovieWriter ({name}) not available")


writers = MovieWriterRegistry()


class AbstractMovieWriter(abc.ABC):
    """
    Abstract base class for writing movies, providing a way to grab frames by
    calling `~AbstractMovieWriter.grab_frame`.

    `setup` is called to start the process and `finish` is called afterwards.
    `saving` is provided as a context manager to facilitate this process as ::

        with moviewriter.saving(fig, outfile='myfile.mp4', dpi=100):
            # Iterate over frames
            moviewriter.grab_frame(**savefig_kwargs)

    The use of the context manager ensures that `setup` and `finish` are
    performed as necessary.

    An instance of a concrete subclass of this class can be given as the
    ``writer`` argument of `Animation.save()`.
    """

    def __init__(self, fps=5, metadata=None, codec=None, bitrate=None):
        self.fps = fps
        self.metadata = metadata if metadata is not None else {}
        self.codec = mpl._val_or_rc(codec, 'animation.codec')
        self.bitrate = mpl._val_or_rc(bitrate, 'animation.bitrate')

    @abc.abstractmethod
    def setup(self, fig, outfile, dpi=None):
        """
        Setup for writing the movie file.

        Parameters
        ----------
        fig : `~matplotlib.figure.Figure`
            The figure object that contains the information for frames.
        outfile : str
            The filename of the resulting movie file.
        dpi : float, default: ``fig.dpi``
            The DPI (or resolution) for the file.  This controls the size
            in pixels of the resulting movie file.
        """
        # Check that path is valid
        Path(outfile).parent.resolve(strict=True)
        self.outfile = outfile
        self.fig = fig
        if dpi is None:
            dpi = self.fig.dpi
        self.dpi = dpi

    @property
    def frame_size(self):
        """A tuple ``(width, height)`` in pixels of a movie frame."""
        w, h = self.fig.get_size_inches()
        return int(w * self.dpi), int(h * self.dpi)

    @abc.abstractmethod
    def grab_frame(self, **savefig_kwargs):
        """
        Grab the image information from the figure and save as a movie frame.

        All keyword arguments in *savefig_kwargs* are passed on to the
        `~.Figure.savefig` call that saves the figure.  However, several
        keyword arguments that are supported by `~.Figure.savefig` may not be
        passed as they are controlled by the MovieWriter:

        - *dpi*, *bbox_inches*:  These may not be passed because each frame of the
           animation much be exactly the same size in pixels.
        - *format*: This is controlled by the MovieWriter.
        """

    @abc.abstractmethod
    def finish(self):
        """Finish any processing for writing the movie."""

    @contextlib.contextmanager
    def saving(self, fig, outfile, dpi, *args, **kwargs):
        """
        Context manager to facilitate writing the movie file.

        ``*args, **kw`` are any parameters that should be passed to `setup`.
        """
        if mpl.rcParams['savefig.bbox'] == 'tight':
            _log.info("Disabling savefig.bbox = 'tight', as it may cause "
                      "frame size to vary, which is inappropriate for "
                      "animation.")

        # This particular sequence is what contextlib.contextmanager wants
        self.setup(fig, outfile, dpi, *args, **kwargs)
        with mpl.rc_context({'savefig.bbox': None}):
            try:
                yield self
            finally:
                self.finish()


class MovieWriter(AbstractMovieWriter):
    """
    Base class for writing movies.

    This is a base class for MovieWriter subclasses that write a movie frame
    data to a pipe. You cannot instantiate this class directly.
    See examples for how to use its subclasses.

    Attributes
    ----------
    frame_format : str
        The format used in writing frame data, defaults to 'rgba'.
    fig : `~matplotlib.figure.Figure`
        The figure to capture data from.
        This must be provided by the subclasses.
    """

    # Builtin writer subclasses additionally define the _exec_key and _args_key
    # attributes, which indicate the rcParams entries where the path to the
    # executable and additional command-line arguments to the executable are
    # stored.  Third-party writers cannot meaningfully set these as they cannot
    # extend rcParams with new keys.

    # Pipe-based writers only support RGBA, but file-based ones support more
    # formats.
    supported_formats = ["rgba"]

    def __init__(self, fps=5, codec=None, bitrate=None, extra_args=None,
                 metadata=None):
        """
        Parameters
        ----------
        fps : int, default: 5
            Movie frame rate (per second).
        codec : str or None, default: :rc:`animation.codec`
            The codec to use.
        bitrate : int, default: :rc:`animation.bitrate`
            The bitrate of the movie, in kilobits per second.  Higher values
            means higher quality movies, but increase the file size.  A value
            of -1 lets the underlying movie encoder select the bitrate.
        extra_args : list of str or None, optional
            Extra command-line arguments passed to the underlying movie encoder. These
            arguments are passed last to the encoder, just before the filename. The
            default, None, means to use :rc:`animation.[name-of-encoder]_args` for the
            builtin writers.
        metadata : dict[str, str], default: {}
            A dictionary of keys and values for metadata to include in the
            output file. Some keys that may be of use include:
            title, artist, genre, subject, copyright, srcform, comment.
        """
        if type(self) is MovieWriter:
            # TODO MovieWriter is still an abstract class and needs to be
            #      extended with a mixin. This should be clearer in naming
            #      and description. For now, just give a reasonable error
            #      message to users.
            raise TypeError(
                'MovieWriter cannot be instantiated directly. Please use one '
                'of its subclasses.')

        super().__init__(fps=fps, metadata=metadata, codec=codec,
                         bitrate=bitrate)
        self.frame_format = self.supported_formats[0]
        self.extra_args = extra_args

    def _adjust_frame_size(self):
        if self.codec == 'h264':
            wo, ho = self.fig.get_size_inches()
            w, h = adjusted_figsize(wo, ho, self.dpi, 2)
            if (wo, ho) != (w, h):
                self.fig.set_size_inches(w, h, forward=True)
                _log.info('figure size in inches has been adjusted '
                          'from %s x %s to %s x %s', wo, ho, w, h)
        else:
            w, h = self.fig.get_size_inches()
        _log.debug('frame size in pixels is %s x %s', *self.frame_size)
        return w, h

    def setup(self, fig, outfile, dpi=None):
        # docstring inherited
        super().setup(fig, outfile, dpi=dpi)
        self._w, self._h = self._adjust_frame_size()
        # Run here so that grab_frame() can write the data to a pipe. This
        # eliminates the need for temp files.
        self._run()

    def _run(self):
        # Uses subprocess to call the program for assembling frames into a
        # movie file.  *args* returns the sequence of command line arguments
        # from a few configuration options.
        command = self._args()
        _log.info('MovieWriter._run: running command: %s',
                  cbook._pformat_subprocess(command))
        PIPE = subprocess.PIPE
        self._proc = subprocess.Popen(
            command, stdin=PIPE, stdout=PIPE, stderr=PIPE,
            creationflags=subprocess_creation_flags)

    def finish(self):
        """Finish any processing for writing the movie."""
        out, err = self._proc.communicate()
        # Use the encoding/errors that universal_newlines would use.
        out = TextIOWrapper(BytesIO(out)).read()
        err = TextIOWrapper(BytesIO(err)).read()
        if out:
            _log.log(
                logging.WARNING if self._proc.returncode else logging.DEBUG,
                "MovieWriter stdout:\n%s", out)
        if err:
            _log.log(
                logging.WARNING if self._proc.returncode else logging.DEBUG,
                "MovieWriter stderr:\n%s", err)
        if self._proc.returncode:
            raise subprocess.CalledProcessError(
                self._proc.returncode, self._proc.args, out, err)

    def grab_frame(self, **savefig_kwargs):
        # docstring inherited
        _validate_grabframe_kwargs(savefig_kwargs)
        _log.debug('MovieWriter.grab_frame: Grabbing frame.')
        # Readjust the figure size in case it has been changed by the user.
        # All frames must have the same size to save the movie correctly.
        self.fig.set_size_inches(self._w, self._h)
        # Save the figure data to the sink, using the frame format and dpi.
        self.fig.savefig(self._proc.stdin, format=self.frame_format,
                         dpi=self.dpi, **savefig_kwargs)

    def _args(self):
        """Assemble list of encoder-specific command-line arguments."""
        return NotImplementedError("args needs to be implemented by subclass.")

    @classmethod
    def bin_path(cls):
        """
        Return the binary path to the commandline tool used by a specific
        subclass. This is a class method so that the tool can be looked for
        before making a particular MovieWriter subclass available.
        """
        return str(mpl.rcParams[cls._exec_key])

    @classmethod
    def isAvailable(cls):
        """Return whether a MovieWriter subclass is actually available."""
        return shutil.which(cls.bin_path()) is not None


class FileMovieWriter(MovieWriter):
    """
    `MovieWriter` for writing to individual files and stitching at the end.

    This must be sub-classed to be useful.
    """
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.frame_format = mpl.rcParams['animation.frame_format']

    def setup(self, fig, outfile, dpi=None, frame_prefix=None):
        """
        Setup for writing the movie file.

        Parameters
        ----------
        fig : `~matplotlib.figure.Figure`
            The figure to grab the rendered frames from.
        outfile : str
            The filename of the resulting movie file.
        dpi : float, default: ``fig.dpi``
            The dpi of the output file. This, with the figure size,
            controls the size in pixels of the resulting movie file.
        frame_prefix : str, optional
            The filename prefix to use for temporary files.  If *None* (the
            default), files are written to a temporary directory which is
            deleted by `finish`; if not *None*, no temporary files are
            deleted.
        """
        # Check that path is valid
        Path(outfile).parent.resolve(strict=True)
        self.fig = fig
        self.outfile = outfile
        if dpi is None:
            dpi = self.fig.dpi
        self.dpi = dpi
        self._adjust_frame_size()

        if frame_prefix is None:
            self._tmpdir = TemporaryDirectory()
            self.temp_prefix = str(Path(self._tmpdir.name, 'tmp'))
        else:
            self._tmpdir = None
            self.temp_prefix = frame_prefix
        self._frame_counter = 0  # used for generating sequential file names
        self._temp_paths = list()
        self.fname_format_str = '%s%%07d.%s'

    def __del__(self):
        if hasattr(self, '_tmpdir') and self._tmpdir:
            self._tmpdir.cleanup()

    @property
    def frame_format(self):
        """
        Format (png, jpeg, etc.) to use for saving the frames, which can be
        decided by the individual subclasses.
        """
        return self._frame_format

    @frame_format.setter
    def frame_format(self, frame_format):
        if frame_format in self.supported_formats:
            self._frame_format = frame_format
        else:
            _api.warn_external(
                f"Ignoring file format {frame_format!r} which is not "
                f"supported by {type(self).__name__}; using "
                f"{self.supported_formats[0]} instead.")
            self._frame_format = self.supported_formats[0]

    def _base_temp_name(self):
        # Generates a template name (without number) given the frame format
        # for extension and the prefix.
        return self.fname_format_str % (self.temp_prefix, self.frame_format)

    def grab_frame(self, **savefig_kwargs):
        # docstring inherited
        # Creates a filename for saving using basename and counter.
        _validate_grabframe_kwargs(savefig_kwargs)
        path = Path(self._base_temp_name() % self._frame_counter)
        self._temp_paths.append(path)  # Record the filename for later use.
        self._frame_counter += 1  # Ensures each created name is unique.
        _log.debug('FileMovieWriter.grab_frame: Grabbing frame %d to path=%s',
                   self._frame_counter, path)
        with open(path, 'wb') as sink:  # Save figure to the sink.
            self.fig.savefig(sink, format=self.frame_format, dpi=self.dpi,
                             **savefig_kwargs)

    def finish(self):
        # Call run here now that all frame grabbing is done. All temp files
        # are available to be assembled.
        try:
            self._run()
            super().finish()
        finally:
            if self._tmpdir:
                _log.debug(
                    'MovieWriter: clearing temporary path=%s', self._tmpdir
                )
                self._tmpdir.cleanup()


@writers.register('pillow')
class PillowWriter(AbstractMovieWriter):
    @classmethod
    def isAvailable(cls):
        return True

    def setup(self, fig, outfile, dpi=None):
        super().setup(fig, outfile, dpi=dpi)
        self._frames = []

    def grab_frame(self, **savefig_kwargs):
        _validate_grabframe_kwargs(savefig_kwargs)
        buf = BytesIO()
        self.fig.savefig(
            buf, **{**savefig_kwargs, "format": "rgba", "dpi": self.dpi})
        self._frames.append(Image.frombuffer(
            "RGBA", self.frame_size, buf.getbuffer(), "raw", "RGBA", 0, 1))

    def finish(self):
        self._frames[0].save(
            self.outfile, save_all=True, append_images=self._frames[1:],
            duration=int(1000 / self.fps), loop=0)


# Base class of ffmpeg information. Has the config keys and the common set
# of arguments that controls the *output* side of things.
class FFMpegBase:
    """
    Mixin class for FFMpeg output.

    This is a base class for the concrete `FFMpegWriter` and `FFMpegFileWriter`
    classes.
    """

    _exec_key = 'animation.ffmpeg_path'
    _args_key = 'animation.ffmpeg_args'

    @property
    def output_args(self):
        args = []
        if Path(self.outfile).suffix == '.gif':
            self.codec = 'gif'
        else:
            args.extend(['-vcodec', self.codec])
        extra_args = (self.extra_args if self.extra_args is not None
                      else mpl.rcParams[self._args_key])
        # For h264, the default format is yuv444p, which is not compatible
        # with quicktime (and others). Specifying yuv420p fixes playback on
        # iOS, as well as HTML5 video in firefox and safari (on both Win and
        # OSX). Also fixes internet explorer. This is as of 2015/10/29.
        if self.codec == 'h264' and '-pix_fmt' not in extra_args:
            args.extend(['-pix_fmt', 'yuv420p'])
        # For GIF, we're telling FFMPEG to split the video stream, to generate
        # a palette, and then use it for encoding.
        elif self.codec == 'gif' and '-filter_complex' not in extra_args:
            args.extend(['-filter_complex',
                         'split [a][b];[a] palettegen [p];[b][p] paletteuse'])
        if self.bitrate > 0:
            args.extend(['-b', '%dk' % self.bitrate])  # %dk: bitrate in kbps.
        for k, v in self.metadata.items():
            args.extend(['-metadata', f'{k}={v}'])
        args.extend(extra_args)

        return args + ['-y', self.outfile]


# Combine FFMpeg options with pipe-based writing
@writers.register('ffmpeg')
class FFMpegWriter(FFMpegBase, MovieWriter):
    """
    Pipe-based ffmpeg writer.

    Frames are streamed directly to ffmpeg via a pipe and written in a single pass.

    This effectively works as a slideshow input to ffmpeg with the fps passed as
    ``-framerate``, so see also `their notes on frame rates`_ for further details.

    .. _their notes on frame rates: https://trac.ffmpeg.org/wiki/Slideshow#Framerates
    """
    def _args(self):
        # Returns the command line parameters for subprocess to use
        # ffmpeg to create a movie using a pipe.
        args = [self.bin_path(), '-f', 'rawvideo', '-vcodec', 'rawvideo',
                '-s', '%dx%d' % self.frame_size, '-pix_fmt', self.frame_format,
                '-framerate', str(self.fps)]
        # Logging is quieted because subprocess.PIPE has limited buffer size.
        # If you have a lot of frames in your animation and set logging to
        # DEBUG, you will have a buffer overrun.
        if _log.getEffectiveLevel() > logging.DEBUG:
            args += ['-loglevel', 'error']
        args += ['-i', 'pipe:'] + self.output_args
        return args


# Combine FFMpeg options with temp file-based writing
@writers.register('ffmpeg_file')
class FFMpegFileWriter(FFMpegBase, FileMovieWriter):
    """
    File-based ffmpeg writer.

    Frames are written to temporary files on disk and then stitched together at the end.

    This effectively works as a slideshow input to ffmpeg with the fps passed as
    ``-framerate``, so see also `their notes on frame rates`_ for further details.

    .. _their notes on frame rates: https://trac.ffmpeg.org/wiki/Slideshow#Framerates
    """
    supported_formats = ['png', 'jpeg', 'tiff', 'raw', 'rgba']

    def _args(self):
        # Returns the command line parameters for subprocess to use
        # ffmpeg to create a movie using a collection of temp images
        args = []
        # For raw frames, we need to explicitly tell ffmpeg the metadata.
        if self.frame_format in {'raw', 'rgba'}:
            args += [
                '-f', 'image2', '-vcodec', 'rawvideo',
                '-video_size', '%dx%d' % self.frame_size,
                '-pixel_format', 'rgba',
            ]
        args += ['-framerate', str(self.fps), '-i', self._base_temp_name()]
        if not self._tmpdir:
            args += ['-frames:v', str(self._frame_counter)]
        # Logging is quieted because subprocess.PIPE has limited buffer size.
        # If you have a lot of frames in your animation and set logging to
        # DEBUG, you will have a buffer overrun.
        if _log.getEffectiveLevel() > logging.DEBUG:
            args += ['-loglevel', 'error']
        return [self.bin_path(), *args, *self.output_args]


# Base class for animated GIFs with ImageMagick
class ImageMagickBase:
    """
    Mixin class for ImageMagick output.

    This is a base class for the concrete `ImageMagickWriter` and
    `ImageMagickFileWriter` classes, which define an ``input_names`` attribute
    (or property) specifying the input names passed to ImageMagick.
    """

    _exec_key = 'animation.convert_path'
    _args_key = 'animation.convert_args'

    def _args(self):
        # ImageMagick does not recognize "raw".
        fmt = "rgba" if self.frame_format == "raw" else self.frame_format
        extra_args = (self.extra_args if self.extra_args is not None
                      else mpl.rcParams[self._args_key])
        return [
            self.bin_path(),
            "-size", "%ix%i" % self.frame_size,
            "-depth", "8",
            "-delay", str(100 / self.fps),
            "-loop", "0",
            f"{fmt}:{self.input_names}",
            *extra_args,
            self.outfile,
        ]

    @classmethod
    def bin_path(cls):
        binpath = super().bin_path()
        if binpath == 'convert':
            binpath = mpl._get_executable_info('magick').executable
        return binpath

    @classmethod
    def isAvailable(cls):
        try:
            return super().isAvailable()
        except mpl.ExecutableNotFoundError as _enf:
            # May be raised by get_executable_info.
            _log.debug('ImageMagick unavailable due to: %s', _enf)
            return False


# Combine ImageMagick options with pipe-based writing
@writers.register('imagemagick')
class ImageMagickWriter(ImageMagickBase, MovieWriter):
    """
    Pipe-based animated gif writer.

    Frames are streamed directly to ImageMagick via a pipe and written
    in a single pass.
    """

    input_names = "-"  # stdin


# Combine ImageMagick options with temp file-based writing
@writers.register('imagemagick_file')
class ImageMagickFileWriter(ImageMagickBase, FileMovieWriter):
    """
    File-based animated gif writer.

    Frames are written to temporary files on disk and then stitched
    together at the end.
    """

    supported_formats = ['png', 'jpeg', 'tiff', 'raw', 'rgba']
    input_names = property(
        lambda self: f'{self.temp_prefix}*.{self.frame_format}')


# Taken directly from jakevdp's JSAnimation package at
# http://github.com/jakevdp/JSAnimation
def _included_frames(frame_count, frame_format, frame_dir):
    return INCLUDED_FRAMES.format(Nframes=frame_count,
                                  frame_dir=frame_dir,
                                  frame_format=frame_format)


def _embedded_frames(frame_list, frame_format):
    """frame_list should be a list of base64-encoded png files"""
    if frame_format == 'svg':
        # Fix MIME type for svg
        frame_format = 'svg+xml'
    template = '  frames[{0}] = "data:image/{1};base64,{2}"\n'
    return "\n" + "".join(
        template.format(i, frame_format, frame_data.replace('\n', '\\\n'))
        for i, frame_data in enumerate(frame_list))


@writers.register('html')
class HTMLWriter(FileMovieWriter):
    """Writer for JavaScript-based HTML movies."""

    supported_formats = ['png', 'jpeg', 'tiff', 'svg']

    @classmethod
    def isAvailable(cls):
        return True

    def __init__(self, fps=30, codec=None, bitrate=None, extra_args=None,
                 metadata=None, embed_frames=False, default_mode='loop',
                 embed_limit=None):

        if extra_args:
            _log.warning("HTMLWriter ignores 'extra_args'")
        extra_args = ()  # Don't lookup nonexistent rcParam[args_key].
        self.embed_frames = embed_frames
        self.default_mode = default_mode.lower()
        _api.check_in_list(['loop', 'once', 'reflect'],
                           default_mode=self.default_mode)

        # Save embed limit, which is given in MB
        self._bytes_limit = mpl._val_or_rc(embed_limit, 'animation.embed_limit')
        # Convert from MB to bytes
        self._bytes_limit *= 1024 * 1024

        super().__init__(fps, codec, bitrate, extra_args, metadata)

    def setup(self, fig, outfile, dpi=None, frame_dir=None):
        outfile = Path(outfile)
        _api.check_in_list(['.html', '.htm'], outfile_extension=outfile.suffix)

        self._saved_frames = []
        self._total_bytes = 0
        self._hit_limit = False

        if not self.embed_frames:
            if frame_dir is None:
                frame_dir = outfile.with_name(outfile.stem + '_frames')
            frame_dir.mkdir(parents=True, exist_ok=True)
            frame_prefix = frame_dir / 'frame'
        else:
            frame_prefix = None

        super().setup(fig, outfile, dpi, frame_prefix)
        self._clear_temp = False

    def grab_frame(self, **savefig_kwargs):
        _validate_grabframe_kwargs(savefig_kwargs)
        if self.embed_frames:
            # Just stop processing if we hit the limit
            if self._hit_limit:
                return
            f = BytesIO()
            self.fig.savefig(f, format=self.frame_format,
                             dpi=self.dpi, **savefig_kwargs)
            imgdata64 = base64.encodebytes(f.getvalue()).decode('ascii')
            self._total_bytes += len(imgdata64)
            if self._total_bytes >= self._bytes_limit:
                _log.warning(
                    "Animation size has reached %s bytes, exceeding the limit "
                    "of %s. If you're sure you want a larger animation "
                    "embedded, set the animation.embed_limit rc parameter to "
                    "a larger value (in MB). This and further frames will be "
                    "dropped.", self._total_bytes, self._bytes_limit)
                self._hit_limit = True
            else:
                self._saved_frames.append(imgdata64)
        else:
            return super().grab_frame(**savefig_kwargs)

    def finish(self):
        # save the frames to an html file
        if self.embed_frames:
            fill_frames = _embedded_frames(self._saved_frames,
                                           self.frame_format)
            frame_count = len(self._saved_frames)
        else:
            # temp names is filled by FileMovieWriter
            frame_count = len(self._temp_paths)
            fill_frames = _included_frames(
                frame_count, self.frame_format,
                self._temp_paths[0].parent.relative_to(self.outfile.parent))
        mode_dict = dict(once_checked='',
                         loop_checked='',
                         reflect_checked='')
        mode_dict[self.default_mode + '_checked'] = 'checked'

        interval = 1000 // self.fps

        with open(self.outfile, 'w') as of:
            of.write(JS_INCLUDE + STYLE_INCLUDE)
            of.write(DISPLAY_TEMPLATE.format(id=uuid.uuid4().hex,
                                             Nframes=frame_count,
                                             fill_frames=fill_frames,
                                             interval=interval,
                                             **mode_dict))

        # Duplicate the temporary file clean up logic from
        # FileMovieWriter.finish.  We cannot call the inherited version of
        # finish because it assumes that there is a subprocess that we either
        # need to call to merge many frames together or that there is a
        # subprocess call that we need to clean up.
        if self._tmpdir:
            _log.debug('MovieWriter: clearing temporary path=%s', self._tmpdir)
            self._tmpdir.cleanup()


class Animation:
    """
    A base class for Animations.

    This class is not usable as is, and should be subclassed to provide needed
    behavior.

    .. note::

        You must store the created Animation in a variable that lives as long
        as the animation should run. Otherwise, the Animation object will be
        garbage-collected and the animation stops.

    Parameters
    ----------
    fig : `~matplotlib.figure.Figure`
        The figure object used to get needed events, such as draw or resize.

    event_source : object, optional
        A class that can run a callback when desired events
        are generated, as well as be stopped and started.

        Examples include timers (see `TimedAnimation`) and file
        system notifications.

    blit : bool, default: False
        Whether blitting is used to optimize drawing.  If the backend does not
        support blitting, then this parameter has no effect.

    See Also
    --------
    FuncAnimation,  ArtistAnimation
    """

    def __init__(self, fig, event_source=None, blit=False):
        self._draw_was_started = False

        self._fig = fig
        # Disables blitting for backends that don't support it.  This
        # allows users to request it if available, but still have a
        # fallback that works if it is not.
        self._blit = blit and fig.canvas.supports_blit

        # These are the basics of the animation.  The frame sequence represents
        # information for each frame of the animation and depends on how the
        # drawing is handled by the subclasses. The event source fires events
        # that cause the frame sequence to be iterated.
        self.frame_seq = self.new_frame_seq()
        self.event_source = event_source

        # Instead of starting the event source now, we connect to the figure's
        # draw_event, so that we only start once the figure has been drawn.
        self._first_draw_id = fig.canvas.mpl_connect('draw_event', self._start)

        # Connect to the figure's close_event so that we don't continue to
        # fire events and try to draw to a deleted figure.
        self._close_id = self._fig.canvas.mpl_connect('close_event',
                                                      self._stop)
        if self._blit:
            self._setup_blit()

    def __del__(self):
        if not getattr(self, '_draw_was_started', True):
            warnings.warn(
                'Animation was deleted without rendering anything. This is '
                'most likely not intended. To prevent deletion, assign the '
                'Animation to a variable, e.g. `anim`, that exists until you '
                'output the Animation using `plt.show()` or '
                '`anim.save()`.'
            )

    def _start(self, *args):
        """
        Starts interactive animation. Adds the draw frame command to the GUI
        handler, calls show to start the event loop.
        """
        # Do not start the event source if saving() it.
        if self._fig.canvas.is_saving():
            return
        # First disconnect our draw event handler
        self._fig.canvas.mpl_disconnect(self._first_draw_id)

        # Now do any initial draw
        self._init_draw()

        # Add our callback for stepping the animation and
        # actually start the event_source.
        self.event_source.add_callback(self._step)
        self.event_source.start()

    def _stop(self, *args):
        # On stop we disconnect all of our events.
        if self._blit:
            self._fig.canvas.mpl_disconnect(self._resize_id)
        self._fig.canvas.mpl_disconnect(self._close_id)
        self.event_source.remove_callback(self._step)
        self.event_source = None

    def save(self, filename, writer=None, fps=None, dpi=None, codec=None,
             bitrate=None, extra_args=None, metadata=None, extra_anim=None,
             savefig_kwargs=None, *, progress_callback=None):
        """
        Save the animation as a movie file by drawing every frame.

        Parameters
        ----------
        filename : str
            The output filename, e.g., :file:`mymovie.mp4`.

        writer : `MovieWriter` or str, default: :rc:`animation.writer`
            A `MovieWriter` instance to use or a key that identifies a
            class to use, such as 'ffmpeg'.

        fps : int, optional
            Movie frame rate (per second).  If not set, the frame rate from the
            animation's frame interval.

        dpi : float, default: :rc:`savefig.dpi`
            Controls the dots per inch for the movie frames.  Together with
            the figure's size in inches, this controls the size of the movie.

        codec : str, default: :rc:`animation.codec`.
            The video codec to use.  Not all codecs are supported by a given
            `MovieWriter`.

        bitrate : int, default: :rc:`animation.bitrate`
            The bitrate of the movie, in kilobits per second.  Higher values
            means higher quality movies, but increase the file size.  A value
            of -1 lets the underlying movie encoder select the bitrate.

        extra_args : list of str or None, optional
            Extra command-line arguments passed to the underlying movie encoder. These
            arguments are passed last to the encoder, just before the output filename.
            The default, None, means to use :rc:`animation.[name-of-encoder]_args` for
            the builtin writers.

        metadata : dict[str, str], default: {}
            Dictionary of keys and values for metadata to include in
            the output file. Some keys that may be of use include:
            title, artist, genre, subject, copyright, srcform, comment.

        extra_anim : list, default: []
            Additional `Animation` objects that should be included
            in the saved movie file. These need to be from the same
            `.Figure` instance. Also, animation frames will
            just be simply combined, so there should be a 1:1 correspondence
            between the frames from the different animations.

        savefig_kwargs : dict, default: {}
            Keyword arguments passed to each `~.Figure.savefig` call used to
            save the individual frames.

        progress_callback : function, optional
            A callback function that will be called for every frame to notify
            the saving progress. It must have the signature ::

                def func(current_frame: int, total_frames: int) -> Any

            where *current_frame* is the current frame number and *total_frames* is the
            total number of frames to be saved. *total_frames* is set to None, if the
            total number of frames cannot be determined. Return values may exist but are
            ignored.

            Example code to write the progress to stdout::

                progress_callback = lambda i, n: print(f'Saving frame {i}/{n}')

        Notes
        -----
        *fps*, *codec*, *bitrate*, *extra_args* and *metadata* are used to
        construct a `.MovieWriter` instance and can only be passed if
        *writer* is a string.  If they are passed as non-*None* and *writer*
        is a `.MovieWriter`, a `RuntimeError` will be raised.
        """

        all_anim = [self]
        if extra_anim is not None:
            all_anim.extend(anim for anim in extra_anim
                            if anim._fig is self._fig)

        # Disable "Animation was deleted without rendering" warning.
        for anim in all_anim:
            anim._draw_was_started = True

        if writer is None:
            writer = mpl.rcParams['animation.writer']
        elif (not isinstance(writer, str) and
              any(arg is not None
                  for arg in (fps, codec, bitrate, extra_args, metadata))):
            raise RuntimeError('Passing in values for arguments '
                               'fps, codec, bitrate, extra_args, or metadata '
                               'is not supported when writer is an existing '
                               'MovieWriter instance. These should instead be '
                               'passed as arguments when creating the '
                               'MovieWriter instance.')

        if savefig_kwargs is None:
            savefig_kwargs = {}
        else:
            # we are going to mutate this below
            savefig_kwargs = dict(savefig_kwargs)

        if fps is None and hasattr(self, '_interval'):
            # Convert interval in ms to frames per second
            fps = 1000. / self._interval

        # Re-use the savefig DPI for ours if none is given
        dpi = mpl._val_or_rc(dpi, 'savefig.dpi')
        if dpi == 'figure':
            dpi = self._fig.dpi

        writer_kwargs = {}
        if codec is not None:
            writer_kwargs['codec'] = codec
        if bitrate is not None:
            writer_kwargs['bitrate'] = bitrate
        if extra_args is not None:
            writer_kwargs['extra_args'] = extra_args
        if metadata is not None:
            writer_kwargs['metadata'] = metadata

        # If we have the name of a writer, instantiate an instance of the
        # registered class.
        if isinstance(writer, str):
            try:
                writer_cls = writers[writer]
            except RuntimeError:  # Raised if not available.
                writer_cls = PillowWriter  # Always available.
                _log.warning("MovieWriter %s unavailable; using Pillow "
                             "instead.", writer)
            writer = writer_cls(fps, **writer_kwargs)
        _log.info('Animation.save using %s', type(writer))

        if 'bbox_inches' in savefig_kwargs:
            _log.warning("Warning: discarding the 'bbox_inches' argument in "
                         "'savefig_kwargs' as it may cause frame size "
                         "to vary, which is inappropriate for animation.")
            savefig_kwargs.pop('bbox_inches')

        # Create a new sequence of frames for saved data. This is different
        # from new_frame_seq() to give the ability to save 'live' generated
        # frame information to be saved later.
        # TODO: Right now, after closing the figure, saving a movie won't work
        # since GUI widgets are gone. Either need to remove extra code to
        # allow for this non-existent use case or find a way to make it work.

        facecolor = savefig_kwargs.get('facecolor',
                                       mpl.rcParams['savefig.facecolor'])
        if facecolor == 'auto':
            facecolor = self._fig.get_facecolor()

        def _pre_composite_to_white(color):
            r, g, b, a = mcolors.to_rgba(color)
            return a * np.array([r, g, b]) + 1 - a

        savefig_kwargs['facecolor'] = _pre_composite_to_white(facecolor)
        savefig_kwargs['transparent'] = False   # just to be safe!
        # canvas._is_saving = True makes the draw_event animation-starting
        # callback a no-op; canvas.manager = None prevents resizing the GUI
        # widget (both are likewise done in savefig()).
        with writer.saving(self._fig, filename, dpi), \
             cbook._setattr_cm(self._fig.canvas, _is_saving=True, manager=None):
            for anim in all_anim:
                anim._init_draw()  # Clear the initial frame
            frame_number = 0
            # TODO: Currently only FuncAnimation has a save_count
            #       attribute. Can we generalize this to all Animations?
            save_count_list = [getattr(a, '_save_count', None)
                               for a in all_anim]
            if None in save_count_list:
                total_frames = None
            else:
                total_frames = sum(save_count_list)
            for data in zip(*[a.new_saved_frame_seq() for a in all_anim]):
                for anim, d in zip(all_anim, data):
                    # TODO: See if turning off blit is really necessary
                    anim._draw_next_frame(d, blit=False)
                    if progress_callback is not None:
                        progress_callback(frame_number, total_frames)
                        frame_number += 1
                writer.grab_frame(**savefig_kwargs)

    def _step(self, *args):
        """
        Handler for getting events. By default, gets the next frame in the
        sequence and hands the data off to be drawn.
        """
        # Returns True to indicate that the event source should continue to
        # call _step, until the frame sequence reaches the end of iteration,
        # at which point False will be returned.
        try:
            framedata = next(self.frame_seq)
            self._draw_next_frame(framedata, self._blit)
            return True
        except StopIteration:
            return False

    def new_frame_seq(self):
        """Return a new sequence of frame information."""
        # Default implementation is just an iterator over self._framedata
        return iter(self._framedata)

    def new_saved_frame_seq(self):
        """Return a new sequence of saved/cached frame information."""
        # Default is the same as the regular frame sequence
        return self.new_frame_seq()

    def _draw_next_frame(self, framedata, blit):
        # Breaks down the drawing of the next frame into steps of pre- and
        # post- draw, as well as the drawing of the frame itself.
        self._pre_draw(framedata, blit)
        self._draw_frame(framedata)
        self._post_draw(framedata, blit)

    def _init_draw(self):
        # Initial draw to clear the frame. Also used by the blitting code
        # when a clean base is required.
        self._draw_was_started = True

    def _pre_draw(self, framedata, blit):
        # Perform any cleaning or whatnot before the drawing of the frame.
        # This default implementation allows blit to clear the frame.
        if blit:
            self._blit_clear(self._drawn_artists)

    def _draw_frame(self, framedata):
        # Performs actual drawing of the frame.
        raise NotImplementedError('Needs to be implemented by subclasses to'
                                  ' actually make an animation.')

    def _post_draw(self, framedata, blit):
        # After the frame is rendered, this handles the actual flushing of
        # the draw, which can be a direct draw_idle() or make use of the
        # blitting.
        if blit and self._drawn_artists:
            self._blit_draw(self._drawn_artists)
        else:
            self._fig.canvas.draw_idle()

    # The rest of the code in this class is to facilitate easy blitting
    def _blit_draw(self, artists):
        # Handles blitted drawing, which renders only the artists given instead
        # of the entire figure.
        updated_ax = {a.axes for a in artists}
        # Enumerate artists to cache Axes backgrounds. We do not draw
        # artists yet to not cache foreground from plots with shared axes
        for ax in updated_ax:
            # If we haven't cached the background for the current view of this
            # Axes object, do so now. This might not always be reliable, but
            # it's an attempt to automate the process.
            cur_view = ax._get_view()
            view, bg = self._blit_cache.get(ax, (object(), None))
            if cur_view != view:
                self._blit_cache[ax] = (
                    cur_view, ax.figure.canvas.copy_from_bbox(ax.bbox))
        # Make a separate pass to draw foreground.
        for a in artists:
            a.axes.draw_artist(a)
        # After rendering all the needed artists, blit each Axes individually.
        for ax in updated_ax:
            ax.figure.canvas.blit(ax.bbox)

    def _blit_clear(self, artists):
        # Get a list of the Axes that need clearing from the artists that
        # have been drawn. Grab the appropriate saved background from the
        # cache and restore.
        axes = {a.axes for a in artists}
        for ax in axes:
            try:
                view, bg = self._blit_cache[ax]
            except KeyError:
                continue
            if ax._get_view() == view:
                ax.figure.canvas.restore_region(bg)
            else:
                self._blit_cache.pop(ax)

    def _setup_blit(self):
        # Setting up the blit requires: a cache of the background for the Axes
        self._blit_cache = dict()
        self._drawn_artists = []
        # _post_draw needs to be called first to initialize the renderer
        self._post_draw(None, self._blit)
        # Then we need to clear the Frame for the initial draw
        # This is typically handled in _on_resize because QT and Tk
        # emit a resize event on launch, but the macosx backend does not,
        # thus we force it here for everyone for consistency
        self._init_draw()
        # Connect to future resize events
        self._resize_id = self._fig.canvas.mpl_connect('resize_event',
                                                       self._on_resize)

    def _on_resize(self, event):
        # On resize, we need to disable the resize event handling so we don't
        # get too many events. Also stop the animation events, so that
        # we're paused. Reset the cache and re-init. Set up an event handler
        # to catch once the draw has actually taken place.
        self._fig.canvas.mpl_disconnect(self._resize_id)
        self.event_source.stop()
        self._blit_cache.clear()
        self._init_draw()
        self._resize_id = self._fig.canvas.mpl_connect('draw_event',
                                                       self._end_redraw)

    def _end_redraw(self, event):
        # Now that the redraw has happened, do the post draw flushing and
        # blit handling. Then re-enable all of the original events.
        self._post_draw(None, False)
        self.event_source.start()
        self._fig.canvas.mpl_disconnect(self._resize_id)
        self._resize_id = self._fig.canvas.mpl_connect('resize_event',
                                                       self._on_resize)

    def to_html5_video(self, embed_limit=None):
        """
        Convert the animation to an HTML5 ``<video>`` tag.

        This saves the animation as an h264 video, encoded in base64
        directly into the HTML5 video tag. This respects :rc:`animation.writer`
        and :rc:`animation.bitrate`. This also makes use of the
        *interval* to control the speed, and uses the *repeat*
        parameter to decide whether to loop.

        Parameters
        ----------
        embed_limit : float, optional
            Limit, in MB, of the returned animation. No animation is created
            if the limit is exceeded.
            Defaults to :rc:`animation.embed_limit` = 20.0.

        Returns
        -------
        str
            An HTML5 video tag with the animation embedded as base64 encoded
            h264 video.
            If the *embed_limit* is exceeded, this returns the string
            "Video too large to embed."
        """
        VIDEO_TAG = r'''<video {size} {options}>
  <source type="video/mp4" src="data:video/mp4;base64,{video}">
  Your browser does not support the video tag.
</video>'''
        # Cache the rendering of the video as HTML
        if not hasattr(self, '_base64_video'):
            # Save embed limit, which is given in MB
            embed_limit = mpl._val_or_rc(embed_limit, 'animation.embed_limit')

            # Convert from MB to bytes
            embed_limit *= 1024 * 1024

            # Can't open a NamedTemporaryFile twice on Windows, so use a
            # TemporaryDirectory instead.
            with TemporaryDirectory() as tmpdir:
                path = Path(tmpdir, "temp.m4v")
                # We create a writer manually so that we can get the
                # appropriate size for the tag
                Writer = writers[mpl.rcParams['animation.writer']]
                writer = Writer(codec='h264',
                                bitrate=mpl.rcParams['animation.bitrate'],
                                fps=1000. / self._interval)
                self.save(str(path), writer=writer)
                # Now open and base64 encode.
                vid64 = base64.encodebytes(path.read_bytes())

            vid_len = len(vid64)
            if vid_len >= embed_limit:
                _log.warning(
                    "Animation movie is %s bytes, exceeding the limit of %s. "
                    "If you're sure you want a large animation embedded, set "
                    "the animation.embed_limit rc parameter to a larger value "
                    "(in MB).", vid_len, embed_limit)
            else:
                self._base64_video = vid64.decode('ascii')
                self._video_size = 'width="{}" height="{}"'.format(
                        *writer.frame_size)

        # If we exceeded the size, this attribute won't exist
        if hasattr(self, '_base64_video'):
            # Default HTML5 options are to autoplay and display video controls
            options = ['controls', 'autoplay']

            # If we're set to repeat, make it loop
            if getattr(self, '_repeat', False):
                options.append('loop')

            return VIDEO_TAG.format(video=self._base64_video,
                                    size=self._video_size,
                                    options=' '.join(options))
        else:
            return 'Video too large to embed.'

    def to_jshtml(self, fps=None, embed_frames=True, default_mode=None):
        """
        Generate HTML representation of the animation.

        Parameters
        ----------
        fps : int, optional
            Movie frame rate (per second). If not set, the frame rate from
            the animation's frame interval.
        embed_frames : bool, optional
        default_mode : str, optional
            What to do when the animation ends. Must be one of ``{'loop',
            'once', 'reflect'}``. Defaults to ``'loop'`` if the *repeat*
            parameter is True, otherwise ``'once'``.
        """
        if fps is None and hasattr(self, '_interval'):
            # Convert interval in ms to frames per second
            fps = 1000 / self._interval

        # If we're not given a default mode, choose one base on the value of
        # the _repeat attribute
        if default_mode is None:
            default_mode = 'loop' if getattr(self, '_repeat',
                                             False) else 'once'

        if not hasattr(self, "_html_representation"):
            # Can't open a NamedTemporaryFile twice on Windows, so use a
            # TemporaryDirectory instead.
            with TemporaryDirectory() as tmpdir:
                path = Path(tmpdir, "temp.html")
                writer = HTMLWriter(fps=fps,
                                    embed_frames=embed_frames,
                                    default_mode=default_mode)
                self.save(str(path), writer=writer)
                self._html_representation = path.read_text()

        return self._html_representation

    def _repr_html_(self):
        """IPython display hook for rendering."""
        fmt = mpl.rcParams['animation.html']
        if fmt == 'html5':
            return self.to_html5_video()
        elif fmt == 'jshtml':
            return self.to_jshtml()

    def pause(self):
        """Pause the animation."""
        self.event_source.stop()
        if self._blit:
            for artist in self._drawn_artists:
                artist.set_animated(False)

    def resume(self):
        """Resume the animation."""
        self.event_source.start()
        if self._blit:
            for artist in self._drawn_artists:
                artist.set_animated(True)


class TimedAnimation(Animation):
    """
    `Animation` subclass for time-based animation.

    A new frame is drawn every *interval* milliseconds.

    .. note::

        You must store the created Animation in a variable that lives as long
        as the animation should run. Otherwise, the Animation object will be
        garbage-collected and the animation stops.

    Parameters
    ----------
    fig : `~matplotlib.figure.Figure`
        The figure object used to get needed events, such as draw or resize.
    interval : int, default: 200
        Delay between frames in milliseconds.
    repeat_delay : int, default: 0
        The delay in milliseconds between consecutive animation runs, if
        *repeat* is True.
    repeat : bool, default: True
        Whether the animation repeats when the sequence of frames is completed.
    blit : bool, default: False
        Whether blitting is used to optimize drawing.
    """
    def __init__(self, fig, interval=200, repeat_delay=0, repeat=True,
                 event_source=None, *args, **kwargs):
        self._interval = interval
        # Undocumented support for repeat_delay = None as backcompat.
        self._repeat_delay = repeat_delay if repeat_delay is not None else 0
        self._repeat = repeat
        # If we're not given an event source, create a new timer. This permits
        # sharing timers between animation objects for syncing animations.
        if event_source is None:
            event_source = fig.canvas.new_timer(interval=self._interval)
        super().__init__(fig, event_source=event_source, *args, **kwargs)

    def _step(self, *args):
        """Handler for getting events."""
        # Extends the _step() method for the Animation class.  If
        # Animation._step signals that it reached the end and we want to
        # repeat, we refresh the frame sequence and return True. If
        # _repeat_delay is set, change the event_source's interval to our loop
        # delay and set the callback to one which will then set the interval
        # back.
        still_going = super()._step(*args)
        if not still_going:
            if self._repeat:
                # Restart the draw loop
                self._init_draw()
                self.frame_seq = self.new_frame_seq()
                self.event_source.interval = self._repeat_delay
                return True
            else:
                # We are done with the animation. Call pause to remove
                # animated flags from artists that were using blitting
                self.pause()
                if self._blit:
                    # Remove the resize callback if we were blitting
                    self._fig.canvas.mpl_disconnect(self._resize_id)
                self._fig.canvas.mpl_disconnect(self._close_id)
                self.event_source = None
                return False

        self.event_source.interval = self._interval
        return True

    repeat = _api.deprecate_privatize_attribute("3.7")


class ArtistAnimation(TimedAnimation):
    """
    `TimedAnimation` subclass that creates an animation by using a fixed
    set of `.Artist` objects.

    Before creating an instance, all plotting should have taken place
    and the relevant artists saved.

    .. note::

        You must store the created Animation in a variable that lives as long
        as the animation should run. Otherwise, the Animation object will be
        garbage-collected and the animation stops.

    Parameters
    ----------
    fig : `~matplotlib.figure.Figure`
        The figure object used to get needed events, such as draw or resize.
    artists : list
        Each list entry is a collection of `.Artist` objects that are made
        visible on the corresponding frame.  Other artists are made invisible.
    interval : int, default: 200
        Delay between frames in milliseconds.
    repeat_delay : int, default: 0
        The delay in milliseconds between consecutive animation runs, if
        *repeat* is True.
    repeat : bool, default: True
        Whether the animation repeats when the sequence of frames is completed.
    blit : bool, default: False
        Whether blitting is used to optimize drawing.
    """

    def __init__(self, fig, artists, *args, **kwargs):
        # Internal list of artists drawn in the most recent frame.
        self._drawn_artists = []

        # Use the list of artists as the framedata, which will be iterated
        # over by the machinery.
        self._framedata = artists
        super().__init__(fig, *args, **kwargs)

    def _init_draw(self):
        super()._init_draw()
        # Make all the artists involved in *any* frame invisible
        figs = set()
        for f in self.new_frame_seq():
            for artist in f:
                artist.set_visible(False)
                artist.set_animated(self._blit)
                # Assemble a list of unique figures that need flushing
                if artist.get_figure() not in figs:
                    figs.add(artist.get_figure())

        # Flush the needed figures
        for fig in figs:
            fig.canvas.draw_idle()

    def _pre_draw(self, framedata, blit):
        """Clears artists from the last frame."""
        if blit:
            # Let blit handle clearing
            self._blit_clear(self._drawn_artists)
        else:
            # Otherwise, make all the artists from the previous frame invisible
            for artist in self._drawn_artists:
                artist.set_visible(False)

    def _draw_frame(self, artists):
        # Save the artists that were passed in as framedata for the other
        # steps (esp. blitting) to use.
        self._drawn_artists = artists

        # Make all the artists from the current frame visible
        for artist in artists:
            artist.set_visible(True)


class FuncAnimation(TimedAnimation):
    """
    `TimedAnimation` subclass that makes an animation by repeatedly calling
    a function *func*.

    .. note::

        You must store the created Animation in a variable that lives as long
        as the animation should run. Otherwise, the Animation object will be
        garbage-collected and the animation stops.

    Parameters
    ----------
    fig : `~matplotlib.figure.Figure`
        The figure object used to get needed events, such as draw or resize.

    func : callable
        The function to call at each frame.  The first argument will
        be the next value in *frames*.   Any additional positional
        arguments can be supplied using `functools.partial` or via the *fargs*
        parameter.

        The required signature is::

            def func(frame, *fargs) -> iterable_of_artists

        It is often more convenient to provide the arguments using
        `functools.partial`. In this way it is also possible to pass keyword
        arguments. To pass a function with both positional and keyword
        arguments, set all arguments as keyword arguments, just leaving the
        *frame* argument unset::

            def func(frame, art, *, y=None):
                ...

            ani = FuncAnimation(fig, partial(func, art=ln, y='foo'))

        If ``blit == True``, *func* must return an iterable of all artists
        that were modified or created. This information is used by the blitting
        algorithm to determine which parts of the figure have to be updated.
        The return value is unused if ``blit == False`` and may be omitted in
        that case.

    frames : iterable, int, generator function, or None, optional
        Source of data to pass *func* and each frame of the animation

        - If an iterable, then simply use the values provided.  If the
          iterable has a length, it will override the *save_count* kwarg.

        - If an integer, then equivalent to passing ``range(frames)``

        - If a generator function, then must have the signature::

             def gen_function() -> obj

        - If *None*, then equivalent to passing ``itertools.count``.

        In all of these cases, the values in *frames* is simply passed through
        to the user-supplied *func* and thus can be of any type.

    init_func : callable, optional
        A function used to draw a clear frame. If not given, the results of
        drawing from the first item in the frames sequence will be used. This
        function will be called once before the first frame.

        The required signature is::

            def init_func() -> iterable_of_artists

        If ``blit == True``, *init_func* must return an iterable of artists
        to be re-drawn. This information is used by the blitting algorithm to
        determine which parts of the figure have to be updated.  The return
        value is unused if ``blit == False`` and may be omitted in that case.

    fargs : tuple or None, optional
        Additional arguments to pass to each call to *func*. Note: the use of
        `functools.partial` is preferred over *fargs*. See *func* for details.

    save_count : int, optional
        Fallback for the number of values from *frames* to cache. This is
        only used if the number of frames cannot be inferred from *frames*,
        i.e. when it's an iterator without length or a generator.

    interval : int, default: 200
        Delay between frames in milliseconds.

    repeat_delay : int, default: 0
        The delay in milliseconds between consecutive animation runs, if
        *repeat* is True.

    repeat : bool, default: True
        Whether the animation repeats when the sequence of frames is completed.

    blit : bool, default: False
        Whether blitting is used to optimize drawing.  Note: when using
        blitting, any animated artists will be drawn according to their zorder;
        however, they will be drawn on top of any previous artists, regardless
        of their zorder.

    cache_frame_data : bool, default: True
        Whether frame data is cached.  Disabling cache might be helpful when
        frames contain large objects.
    """
    def __init__(self, fig, func, frames=None, init_func=None, fargs=None,
                 save_count=None, *, cache_frame_data=True, **kwargs):
        if fargs:
            self._args = fargs
        else:
            self._args = ()
        self._func = func
        self._init_func = init_func

        # Amount of framedata to keep around for saving movies. This is only
        # used if we don't know how many frames there will be: in the case
        # of no generator or in the case of a callable.
        self._save_count = save_count
        # Set up a function that creates a new iterable when needed. If nothing
        # is passed in for frames, just use itertools.count, which will just
        # keep counting from 0. A callable passed in for frames is assumed to
        # be a generator. An iterable will be used as is, and anything else
        # will be treated as a number of frames.
        if frames is None:
            self._iter_gen = itertools.count
        elif callable(frames):
            self._iter_gen = frames
        elif np.iterable(frames):
            if kwargs.get('repeat', True):
                self._tee_from = frames
                def iter_frames(frames=frames):
                    this, self._tee_from = itertools.tee(self._tee_from, 2)
                    yield from this
                self._iter_gen = iter_frames
            else:
                self._iter_gen = lambda: iter(frames)
            if hasattr(frames, '__len__'):
                self._save_count = len(frames)
                if save_count is not None:
                    _api.warn_external(
                        f"You passed in an explicit {save_count=} "
                        "which is being ignored in favor of "
                        f"{len(frames)=}."
                    )
        else:
            self._iter_gen = lambda: iter(range(frames))
            self._save_count = frames
            if save_count is not None:
                _api.warn_external(
                    f"You passed in an explicit {save_count=} which is being "
                    f"ignored in favor of {frames=}."
                )
        if self._save_count is None and cache_frame_data:
            _api.warn_external(
                f"{frames=!r} which we can infer the length of, "
                "did not pass an explicit *save_count* "
                f"and passed {cache_frame_data=}.  To avoid a possibly "
                "unbounded cache, frame data caching has been disabled. "
                "To suppress this warning either pass "
                "`cache_frame_data=False` or `save_count=MAX_FRAMES`."
            )
            cache_frame_data = False

        self._cache_frame_data = cache_frame_data

        # Needs to be initialized so the draw functions work without checking
        self._save_seq = []

        super().__init__(fig, **kwargs)

        # Need to reset the saved seq, since right now it will contain data
        # for a single frame from init, which is not what we want.
        self._save_seq = []

    def new_frame_seq(self):
        # Use the generating function to generate a new frame sequence
        return self._iter_gen()

    def new_saved_frame_seq(self):
        # Generate an iterator for the sequence of saved data. If there are
        # no saved frames, generate a new frame sequence and take the first
        # save_count entries in it.
        if self._save_seq:
            # While iterating we are going to update _save_seq
            # so make a copy to safely iterate over
            self._old_saved_seq = list(self._save_seq)
            return iter(self._old_saved_seq)
        else:
            if self._save_count is None:
                frame_seq = self.new_frame_seq()

                def gen():
                    try:
                        while True:
                            yield next(frame_seq)
                    except StopIteration:
                        pass
                return gen()
            else:
                return itertools.islice(self.new_frame_seq(), self._save_count)

    def _init_draw(self):
        super()._init_draw()
        # Initialize the drawing either using the given init_func or by
        # calling the draw function with the first item of the frame sequence.
        # For blitting, the init_func should return a sequence of modified
        # artists.
        if self._init_func is None:
            try:
                frame_data = next(self.new_frame_seq())
            except StopIteration:
                # we can't start the iteration, it may have already been
                # exhausted by a previous save or just be 0 length.
                # warn and bail.
                warnings.warn(
                    "Can not start iterating the frames for the initial draw. "
                    "This can be caused by passing in a 0 length sequence "
                    "for *frames*.\n\n"
                    "If you passed *frames* as a generator "
                    "it may be exhausted due to a previous display or save."
                )
                return
            self._draw_frame(frame_data)
        else:
            self._drawn_artists = self._init_func()
            if self._blit:
                if self._drawn_artists is None:
                    raise RuntimeError('The init_func must return a '
                                       'sequence of Artist objects.')
                for a in self._drawn_artists:
                    a.set_animated(self._blit)
        self._save_seq = []

    def _draw_frame(self, framedata):
        if self._cache_frame_data:
            # Save the data for potential saving of movies.
            self._save_seq.append(framedata)
            self._save_seq = self._save_seq[-self._save_count:]

        # Call the func with framedata and args. If blitting is desired,
        # func needs to return a sequence of any artists that were modified.
        self._drawn_artists = self._func(framedata, *self._args)

        if self._blit:

            err = RuntimeError('The animation function must return a sequence '
                               'of Artist objects.')
            try:
                # check if a sequence
                iter(self._drawn_artists)
            except TypeError:
                raise err from None

            # check each item if it's artist
            for i in self._drawn_artists:
                if not isinstance(i, mpl.artist.Artist):
                    raise err

            self._drawn_artists = sorted(self._drawn_artists,
                                         key=lambda x: x.get_zorder())

            for a in self._drawn_artists:
                a.set_animated(self._blit)

    save_count = _api.deprecate_privatize_attribute("3.7")


def _validate_grabframe_kwargs(savefig_kwargs):
    if mpl.rcParams['savefig.bbox'] == 'tight':
        raise ValueError(
            f"{mpl.rcParams['savefig.bbox']=} must not be 'tight' as it "
            "may cause frame size to vary, which is inappropriate for animation."
        )
    for k in ('dpi', 'bbox_inches', 'format'):
        if k in savefig_kwargs:
            raise TypeError(
                f"grab_frame got an unexpected keyword argument {k!r}"
            )