aboutsummaryrefslogtreecommitdiffstats
path: root/libavfilter/avfilter.c
blob: 1004a6ee1dc5e63346ef331448ae03f92f5f911f (plain) (blame)
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
/*
 * filter layer
 * Copyright (c) 2007 Bobby Bingham
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/buffer.h"
#include "libavutil/channel_layout.h"
#include "libavutil/common.h"
#include "libavutil/eval.h"
#include "libavutil/hwcontext.h"
#include "libavutil/imgutils.h"
#include "libavutil/internal.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libavutil/rational.h"
#include "libavutil/samplefmt.h"
#include "libavutil/thread.h"

#define FF_INTERNAL_FIELDS 1
#include "framequeue.h"

#include "audio.h"
#include "avfilter.h"
#include "filters.h"
#include "formats.h"
#include "internal.h"

#include "libavutil/ffversion.h"
const char av_filter_ffversion[] = "FFmpeg version " FFMPEG_VERSION;

void ff_tlog_ref(void *ctx, AVFrame *ref, int end)
{
    av_unused char buf[16];
    ff_tlog(ctx,
            "ref[%p buf:%p data:%p linesize[%d, %d, %d, %d] pts:%"PRId64" pos:%"PRId64,
            ref, ref->buf, ref->data[0],
            ref->linesize[0], ref->linesize[1], ref->linesize[2], ref->linesize[3],
            ref->pts, ref->pkt_pos);

    if (ref->width) {
        ff_tlog(ctx, " a:%d/%d s:%dx%d i:%c iskey:%d type:%c",
                ref->sample_aspect_ratio.num, ref->sample_aspect_ratio.den,
                ref->width, ref->height,
                !ref->interlaced_frame     ? 'P' :         /* Progressive  */
                ref->top_field_first ? 'T' : 'B',    /* Top / Bottom */
                ref->key_frame,
                av_get_picture_type_char(ref->pict_type));
    }
    if (ref->nb_samples) {
        ff_tlog(ctx, " cl:%"PRId64"d n:%d r:%d",
                ref->channel_layout,
                ref->nb_samples,
                ref->sample_rate);
    }

    ff_tlog(ctx, "]%s", end ? "\n" : "");
}

unsigned avfilter_version(void)
{
    av_assert0(LIBAVFILTER_VERSION_MICRO >= 100);
    return LIBAVFILTER_VERSION_INT;
}

const char *avfilter_configuration(void)
{
    return FFMPEG_CONFIGURATION;
}

const char *avfilter_license(void)
{
#define LICENSE_PREFIX "libavfilter license: "
    return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;
}

void ff_command_queue_pop(AVFilterContext *filter)
{
    AVFilterCommand *c= filter->command_queue;
    av_freep(&c->arg);
    av_freep(&c->command);
    filter->command_queue= c->next;
    av_free(c);
}

int ff_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
                   AVFilterPad **pads, AVFilterLink ***links,
                   AVFilterPad *newpad)
{
    AVFilterLink **newlinks;
    AVFilterPad *newpads;
    unsigned i;

    idx = FFMIN(idx, *count);

    newpads  = av_realloc_array(*pads,  *count + 1, sizeof(AVFilterPad));
    newlinks = av_realloc_array(*links, *count + 1, sizeof(AVFilterLink*));
    if (newpads)
        *pads  = newpads;
    if (newlinks)
        *links = newlinks;
    if (!newpads || !newlinks)
        return AVERROR(ENOMEM);

    memmove(*pads  + idx + 1, *pads  + idx, sizeof(AVFilterPad)   * (*count - idx));
    memmove(*links + idx + 1, *links + idx, sizeof(AVFilterLink*) * (*count - idx));
    memcpy(*pads + idx, newpad, sizeof(AVFilterPad));
    (*links)[idx] = NULL;

    (*count)++;
    for (i = idx + 1; i < *count; i++)
        if ((*links)[i])
            (*(unsigned *)((uint8_t *) (*links)[i] + padidx_off))++;

    return 0;
}

int avfilter_link(AVFilterContext *src, unsigned srcpad,
                  AVFilterContext *dst, unsigned dstpad)
{
    AVFilterLink *link;

    av_assert0(src->graph);
    av_assert0(dst->graph);
    av_assert0(src->graph == dst->graph);

    if (src->nb_outputs <= srcpad || dst->nb_inputs <= dstpad ||
        src->outputs[srcpad]      || dst->inputs[dstpad])
        return AVERROR(EINVAL);

    if (src->output_pads[srcpad].type != dst->input_pads[dstpad].type) {
        av_log(src, AV_LOG_ERROR,
               "Media type mismatch between the '%s' filter output pad %d (%s) and the '%s' filter input pad %d (%s)\n",
               src->name, srcpad, (char *)av_x_if_null(av_get_media_type_string(src->output_pads[srcpad].type), "?"),
               dst->name, dstpad, (char *)av_x_if_null(av_get_media_type_string(dst-> input_pads[dstpad].type), "?"));
        return AVERROR(EINVAL);
    }

    link = av_mallocz(sizeof(*link));
    if (!link)
        return AVERROR(ENOMEM);

    src->outputs[srcpad] = dst->inputs[dstpad] = link;

    link->src     = src;
    link->dst     = dst;
    link->srcpad  = &src->output_pads[srcpad];
    link->dstpad  = &dst->input_pads[dstpad];
    link->type    = src->output_pads[srcpad].type;
    av_assert0(AV_PIX_FMT_NONE == -1 && AV_SAMPLE_FMT_NONE == -1);
    link->format  = -1;
    ff_framequeue_init(&link->fifo, &src->graph->internal->frame_queues);

    return 0;
}

void avfilter_link_free(AVFilterLink **link)
{
    if (!*link)
        return;

    av_frame_free(&(*link)->partial_buf);
    ff_framequeue_free(&(*link)->fifo);
    ff_frame_pool_uninit((FFFramePool**)&(*link)->frame_pool);

    av_freep(link);
}

#if FF_API_FILTER_GET_SET
int avfilter_link_get_channels(AVFilterLink *link)
{
    return link->channels;
}
#endif

void ff_filter_set_ready(AVFilterContext *filter, unsigned priority)
{
    filter->ready = FFMAX(filter->ready, priority);
}

/**
 * Clear frame_blocked_in on all outputs.
 * This is necessary whenever something changes on input.
 */
static void filter_unblock(AVFilterContext *filter)
{
    unsigned i;

    for (i = 0; i < filter->nb_outputs; i++)
        filter->outputs[i]->frame_blocked_in = 0;
}


void ff_avfilter_link_set_in_status(AVFilterLink *link, int status, int64_t pts)
{
    if (link->status_in == status)
        return;
    av_assert0(!link->status_in);
    link->status_in = status;
    link->status_in_pts = pts;
    link->frame_wanted_out = 0;
    link->frame_blocked_in = 0;
    filter_unblock(link->dst);
    ff_filter_set_ready(link->dst, 200);
}

void ff_avfilter_link_set_out_status(AVFilterLink *link, int status, int64_t pts)
{
    av_assert0(!link->frame_wanted_out);
    av_assert0(!link->status_out);
    link->status_out = status;
    if (pts != AV_NOPTS_VALUE)
        ff_update_link_current_pts(link, pts);
    filter_unblock(link->dst);
    ff_filter_set_ready(link->src, 200);
}

void avfilter_link_set_closed(AVFilterLink *link, int closed)
{
    ff_avfilter_link_set_out_status(link, closed ? AVERROR_EOF : 0, AV_NOPTS_VALUE);
}

int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
                           unsigned filt_srcpad_idx, unsigned filt_dstpad_idx)
{
    int ret;
    unsigned dstpad_idx = link->dstpad - link->dst->input_pads;

    av_log(link->dst, AV_LOG_VERBOSE, "auto-inserting filter '%s' "
           "between the filter '%s' and the filter '%s'\n",
           filt->name, link->src->name, link->dst->name);

    link->dst->inputs[dstpad_idx] = NULL;
    if ((ret = avfilter_link(filt, filt_dstpad_idx, link->dst, dstpad_idx)) < 0) {
        /* failed to link output filter to new filter */
        link->dst->inputs[dstpad_idx] = link;
        return ret;
    }

    /* re-hookup the link to the new destination filter we inserted */
    link->dst                     = filt;
    link->dstpad                  = &filt->input_pads[filt_srcpad_idx];
    filt->inputs[filt_srcpad_idx] = link;

    /* if any information on supported media formats already exists on the
     * link, we need to preserve that */
    if (link->out_formats)
        ff_formats_changeref(&link->out_formats,
                             &filt->outputs[filt_dstpad_idx]->out_formats);
    if (link->out_samplerates)
        ff_formats_changeref(&link->out_samplerates,
                             &filt->outputs[filt_dstpad_idx]->out_samplerates);
    if (link->out_channel_layouts)
        ff_channel_layouts_changeref(&link->out_channel_layouts,
                                     &filt->outputs[filt_dstpad_idx]->out_channel_layouts);

    return 0;
}

int avfilter_config_links(AVFilterContext *filter)
{
    int (*config_link)(AVFilterLink *);
    unsigned i;
    int ret;

    for (i = 0; i < filter->nb_inputs; i ++) {
        AVFilterLink *link = filter->inputs[i];
        AVFilterLink *inlink;

        if (!link) continue;
        if (!link->src || !link->dst) {
            av_log(filter, AV_LOG_ERROR,
                   "Not all input and output are properly linked (%d).\n", i);
            return AVERROR(EINVAL);
        }

        inlink = link->src->nb_inputs ? link->src->inputs[0] : NULL;
        link->current_pts =
        link->current_pts_us = AV_NOPTS_VALUE;

        switch (link->init_state) {
        case AVLINK_INIT:
            continue;
        case AVLINK_STARTINIT:
            av_log(filter, AV_LOG_INFO, "circular filter chain detected\n");
            return 0;
        case AVLINK_UNINIT:
            link->init_state = AVLINK_STARTINIT;

            if ((ret = avfilter_config_links(link->src)) < 0)
                return ret;

            if (!(config_link = link->srcpad->config_props)) {
                if (link->src->nb_inputs != 1) {
                    av_log(link->src, AV_LOG_ERROR, "Source filters and filters "
                                                    "with more than one input "
                                                    "must set config_props() "
                                                    "callbacks on all outputs\n");
                    return AVERROR(EINVAL);
                }
            } else if ((ret = config_link(link)) < 0) {
                av_log(link->src, AV_LOG_ERROR,
                       "Failed to configure output pad on %s\n",
                       link->src->name);
                return ret;
            }

            switch (link->type) {
            case AVMEDIA_TYPE_VIDEO:
                if (!link->time_base.num && !link->time_base.den)
                    link->time_base = inlink ? inlink->time_base : AV_TIME_BASE_Q;

                if (!link->sample_aspect_ratio.num && !link->sample_aspect_ratio.den)
                    link->sample_aspect_ratio = inlink ?
                        inlink->sample_aspect_ratio : (AVRational){1,1};

                if (inlink) {
                    if (!link->frame_rate.num && !link->frame_rate.den)
                        link->frame_rate = inlink->frame_rate;
                    if (!link->w)
                        link->w = inlink->w;
                    if (!link->h)
                        link->h = inlink->h;
                } else if (!link->w || !link->h) {
                    av_log(link->src, AV_LOG_ERROR,
                           "Video source filters must set their output link's "
                           "width and height\n");
                    return AVERROR(EINVAL);
                }
                break;

            case AVMEDIA_TYPE_AUDIO:
                if (inlink) {
                    if (!link->time_base.num && !link->time_base.den)
                        link->time_base = inlink->time_base;
                }

                if (!link->time_base.num && !link->time_base.den)
                    link->time_base = (AVRational) {1, link->sample_rate};
            }

            if (link->src->nb_inputs && link->src->inputs[0]->hw_frames_ctx &&
                !(link->src->filter->flags_internal & FF_FILTER_FLAG_HWFRAME_AWARE)) {
                av_assert0(!link->hw_frames_ctx &&
                           "should not be set by non-hwframe-aware filter");
                link->hw_frames_ctx = av_buffer_ref(link->src->inputs[0]->hw_frames_ctx);
                if (!link->hw_frames_ctx)
                    return AVERROR(ENOMEM);
            }

            if ((config_link = link->dstpad->config_props))
                if ((ret = config_link(link)) < 0) {
                    av_log(link->dst, AV_LOG_ERROR,
                           "Failed to configure input pad on %s\n",
                           link->dst->name);
                    return ret;
                }

            link->init_state = AVLINK_INIT;
        }
    }

    return 0;
}

void ff_tlog_link(void *ctx, AVFilterLink *link, int end)
{
    if (link->type == AVMEDIA_TYPE_VIDEO) {
        ff_tlog(ctx,
                "link[%p s:%dx%d fmt:%s %s->%s]%s",
                link, link->w, link->h,
                av_get_pix_fmt_name(link->format),
                link->src ? link->src->filter->name : "",
                link->dst ? link->dst->filter->name : "",
                end ? "\n" : "");
    } else {
        char buf[128];
        av_get_channel_layout_string(buf, sizeof(buf), -1, link->channel_layout);

        ff_tlog(ctx,
                "link[%p r:%d cl:%s fmt:%s %s->%s]%s",
                link, (int)link->sample_rate, buf,
                av_get_sample_fmt_name(link->format),
                link->src ? link->src->filter->name : "",
                link->dst ? link->dst->filter->name : "",
                end ? "\n" : "");
    }
}

int ff_request_frame(AVFilterLink *link)
{
    FF_TPRINTF_START(NULL, request_frame); ff_tlog_link(NULL, link, 1);

    av_assert1(!link->dst->filter->activate);
    if (link->status_out)
        return link->status_out;
    if (link->status_in) {
        if (ff_framequeue_queued_frames(&link->fifo)) {
            av_assert1(!link->frame_wanted_out);
            av_assert1(link->dst->ready >= 300);
            return 0;
        } else {
            /* Acknowledge status change. Filters using ff_request_frame() will
               handle the change automatically. Filters can also check the
               status directly but none do yet. */
            ff_avfilter_link_set_out_status(link, link->status_in, link->status_in_pts);
            return link->status_out;
        }
    }
    link->frame_wanted_out = 1;
    ff_filter_set_ready(link->src, 100);
    return 0;
}

static int64_t guess_status_pts(AVFilterContext *ctx, int status, AVRational link_time_base)
{
    unsigned i;
    int64_t r = INT64_MAX;

    for (i = 0; i < ctx->nb_inputs; i++)
        if (ctx->inputs[i]->status_out == status)
            r = FFMIN(r, av_rescale_q(ctx->inputs[i]->current_pts, ctx->inputs[i]->time_base, link_time_base));
    if (r < INT64_MAX)
        return r;
    av_log(ctx, AV_LOG_WARNING, "EOF timestamp not reliable\n");
    for (i = 0; i < ctx->nb_inputs; i++)
        r = FFMIN(r, av_rescale_q(ctx->inputs[i]->status_in_pts, ctx->inputs[i]->time_base, link_time_base));
    if (r < INT64_MAX)
        return r;
    return AV_NOPTS_VALUE;
}

static int ff_request_frame_to_filter(AVFilterLink *link)
{
    int ret = -1;

    FF_TPRINTF_START(NULL, request_frame_to_filter); ff_tlog_link(NULL, link, 1);
    /* Assume the filter is blocked, let the method clear it if not */
    link->frame_blocked_in = 1;
    if (link->srcpad->request_frame)
        ret = link->srcpad->request_frame(link);
    else if (link->src->inputs[0])
        ret = ff_request_frame(link->src->inputs[0]);
    if (ret < 0) {
        if (ret != AVERROR(EAGAIN) && ret != link->status_in)
            ff_avfilter_link_set_in_status(link, ret, guess_status_pts(link->src, ret, link->time_base));
        if (ret == AVERROR_EOF)
            ret = 0;
    }
    return ret;
}

int ff_poll_frame(AVFilterLink *link)
{
    int i, min = INT_MAX;

    if (link->srcpad->poll_frame)
        return link->srcpad->poll_frame(link);

    for (i = 0; i < link->src->nb_inputs; i++) {
        int val;
        if (!link->src->inputs[i])
            return AVERROR(EINVAL);
        val = ff_poll_frame(link->src->inputs[i]);
        min = FFMIN(min, val);
    }

    return min;
}

static const char *const var_names[] = {
    "t",
    "n",
    "pos",
    "w",
    "h",
    NULL
};

enum {
    VAR_T,
    VAR_N,
    VAR_POS,
    VAR_W,
    VAR_H,
    VAR_VARS_NB
};

static int set_enable_expr(AVFilterContext *ctx, const char *expr)
{
    int ret;
    char *expr_dup;
    AVExpr *old = ctx->enable;

    if (!(ctx->filter->flags & AVFILTER_FLAG_SUPPORT_TIMELINE)) {
        av_log(ctx, AV_LOG_ERROR, "Timeline ('enable' option) not supported "
               "with filter '%s'\n", ctx->filter->name);
        return AVERROR_PATCHWELCOME;
    }

    expr_dup = av_strdup(expr);
    if (!expr_dup)
        return AVERROR(ENOMEM);

    if (!ctx->var_values) {
        ctx->var_values = av_calloc(VAR_VARS_NB, sizeof(*ctx->var_values));
        if (!ctx->var_values) {
            av_free(expr_dup);
            return AVERROR(ENOMEM);
        }
    }

    ret = av_expr_parse((AVExpr**)&ctx->enable, expr_dup, var_names,
                        NULL, NULL, NULL, NULL, 0, ctx->priv);
    if (ret < 0) {
        av_log(ctx->priv, AV_LOG_ERROR,
               "Error when evaluating the expression '%s' for enable\n",
               expr_dup);
        av_free(expr_dup);
        return ret;
    }

    av_expr_free(old);
    av_free(ctx->enable_str);
    ctx->enable_str = expr_dup;
    return 0;
}

void ff_update_link_current_pts(AVFilterLink *link, int64_t pts)
{
    if (pts == AV_NOPTS_VALUE)
        return;
    link->current_pts = pts;
    link->current_pts_us = av_rescale_q(pts, link->time_base, AV_TIME_BASE_Q);
    /* TODO use duration */
    if (link->graph && link->age_index >= 0)
        ff_avfilter_graph_update_heap(link->graph, link);
}

int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags)
{
    if(!strcmp(cmd, "ping")){
        char local_res[256] = {0};

        if (!res) {
            res = local_res;
            res_len = sizeof(local_res);
        }
        av_strlcatf(res, res_len, "pong from:%s %s\n", filter->filter->name, filter->name);
        if (res == local_res)
            av_log(filter, AV_LOG_INFO, "%s", res);
        return 0;
    }else if(!strcmp(cmd, "enable")) {
        return set_enable_expr(filter, arg);
    }else if(filter->filter->process_command) {
        return filter->filter->process_command(filter, cmd, arg, res, res_len, flags);
    }
    return AVERROR(ENOSYS);
}

int avfilter_pad_count(const AVFilterPad *pads)
{
    int count;

    if (!pads)
        return 0;

    for (count = 0; pads->name; count++)
        pads++;
    return count;
}

static const char *default_filter_name(void *filter_ctx)
{
    AVFilterContext *ctx = filter_ctx;
    return ctx->name ? ctx->name : ctx->filter->name;
}

static void *filter_child_next(void *obj, void *prev)
{
    AVFilterContext *ctx = obj;
    if (!prev && ctx->filter && ctx->filter->priv_class && ctx->priv)
        return ctx->priv;
    return NULL;
}

static const AVClass *filter_child_class_next(const AVClass *prev)
{
    void *opaque = NULL;
    const AVFilter *f = NULL;

    /* find the filter that corresponds to prev */
    while (prev && (f = av_filter_iterate(&opaque)))
        if (f->priv_class == prev)
            break;

    /* could not find filter corresponding to prev */
    if (prev && !f)
        return NULL;

    /* find next filter with specific options */
    while ((f = av_filter_iterate(&opaque)))
        if (f->priv_class)
            return f->priv_class;

    return NULL;
}

#define OFFSET(x) offsetof(AVFilterContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM
static const AVOption avfilter_options[] = {
    { "thread_type", "Allowed thread types", OFFSET(thread_type), AV_OPT_TYPE_FLAGS,
        { .i64 = AVFILTER_THREAD_SLICE }, 0, INT_MAX, FLAGS, "thread_type" },
        { "slice", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AVFILTER_THREAD_SLICE }, .flags = FLAGS, .unit = "thread_type" },
    { "enable", "set enable expression", OFFSET(enable_str), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
    { "threads", "Allowed number of threads", OFFSET(nb_threads), AV_OPT_TYPE_INT,
        { .i64 = 0 }, 0, INT_MAX, FLAGS },
    { "extra_hw_frames", "Number of extra hardware frames to allocate for the user",
        OFFSET(extra_hw_frames), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, FLAGS },
    { NULL },
};

static const AVClass avfilter_class = {
    .class_name = "AVFilter",
    .item_name  = default_filter_name,
    .version    = LIBAVUTIL_VERSION_INT,
    .category   = AV_CLASS_CATEGORY_FILTER,
    .child_next = filter_child_next,
    .child_class_next = filter_child_class_next,
    .option           = avfilter_options,
};

static int default_execute(AVFilterContext *ctx, avfilter_action_func *func, void *arg,
                           int *ret, int nb_jobs)
{
    int i;

    for (i = 0; i < nb_jobs; i++) {
        int r = func(ctx, arg, i, nb_jobs);
        if (ret)
            ret[i] = r;
    }
    return 0;
}

AVFilterContext *ff_filter_alloc(const AVFilter *filter, const char *inst_name)
{
    AVFilterContext *ret;
    int preinited = 0;

    if (!filter)
        return NULL;

    ret = av_mallocz(sizeof(AVFilterContext));
    if (!ret)
        return NULL;

    ret->av_class = &avfilter_class;
    ret->filter   = filter;
    ret->name     = inst_name ? av_strdup(inst_name) : NULL;
    if (filter->priv_size) {
        ret->priv     = av_mallocz(filter->priv_size);
        if (!ret->priv)
            goto err;
    }
    if (filter->preinit) {
        if (filter->preinit(ret) < 0)
            goto err;
        preinited = 1;
    }

    av_opt_set_defaults(ret);
    if (filter->priv_class) {
        *(const AVClass**)ret->priv = filter->priv_class;
        av_opt_set_defaults(ret->priv);
    }

    ret->internal = av_mallocz(sizeof(*ret->internal));
    if (!ret->internal)
        goto err;
    ret->internal->execute = default_execute;

    ret->nb_inputs = avfilter_pad_count(filter->inputs);
    if (ret->nb_inputs ) {
        ret->input_pads   = av_malloc_array(ret->nb_inputs, sizeof(AVFilterPad));
        if (!ret->input_pads)
            goto err;
        memcpy(ret->input_pads, filter->inputs, sizeof(AVFilterPad) * ret->nb_inputs);
        ret->inputs       = av_mallocz_array(ret->nb_inputs, sizeof(AVFilterLink*));
        if (!ret->inputs)
            goto err;
    }

    ret->nb_outputs = avfilter_pad_count(filter->outputs);
    if (ret->nb_outputs) {
        ret->output_pads  = av_malloc_array(ret->nb_outputs, sizeof(AVFilterPad));
        if (!ret->output_pads)
            goto err;
        memcpy(ret->output_pads, filter->outputs, sizeof(AVFilterPad) * ret->nb_outputs);
        ret->outputs      = av_mallocz_array(ret->nb_outputs, sizeof(AVFilterLink*));
        if (!ret->outputs)
            goto err;
    }

    return ret;

err:
    if (preinited)
        filter->uninit(ret);
    av_freep(&ret->inputs);
    av_freep(&ret->input_pads);
    ret->nb_inputs = 0;
    av_freep(&ret->outputs);
    av_freep(&ret->output_pads);
    ret->nb_outputs = 0;
    av_freep(&ret->priv);
    av_freep(&ret->internal);
    av_free(ret);
    return NULL;
}

static void free_link(AVFilterLink *link)
{
    if (!link)
        return;

    if (link->src)
        link->src->outputs[link->srcpad - link->src->output_pads] = NULL;
    if (link->dst)
        link->dst->inputs[link->dstpad - link->dst->input_pads] = NULL;

    av_buffer_unref(&link->hw_frames_ctx);

    ff_formats_unref(&link->in_formats);
    ff_formats_unref(&link->out_formats);
    ff_formats_unref(&link->in_samplerates);
    ff_formats_unref(&link->out_samplerates);
    ff_channel_layouts_unref(&link->in_channel_layouts);
    ff_channel_layouts_unref(&link->out_channel_layouts);
    avfilter_link_free(&link);
}

void avfilter_free(AVFilterContext *filter)
{
    int i;

    if (!filter)
        return;

    if (filter->graph)
        ff_filter_graph_remove_filter(filter->graph, filter);

    if (filter->filter->uninit)
        filter->filter->uninit(filter);

    for (i = 0; i < filter->nb_inputs; i++) {
        free_link(filter->inputs[i]);
    }
    for (i = 0; i < filter->nb_outputs; i++) {
        free_link(filter->outputs[i]);
    }

    if (filter->filter->priv_class)
        av_opt_free(filter->priv);

    av_buffer_unref(&filter->hw_device_ctx);

    av_freep(&filter->name);
    av_freep(&filter->input_pads);
    av_freep(&filter->output_pads);
    av_freep(&filter->inputs);
    av_freep(&filter->outputs);
    av_freep(&filter->priv);
    while(filter->command_queue){
        ff_command_queue_pop(filter);
    }
    av_opt_free(filter);
    av_expr_free(filter->enable);
    filter->enable = NULL;
    av_freep(&filter->var_values);
    av_freep(&filter->internal);
    av_free(filter);
}

int ff_filter_get_nb_threads(AVFilterContext *ctx)
{
    if (ctx->nb_threads > 0)
        return FFMIN(ctx->nb_threads, ctx->graph->nb_threads);
    return ctx->graph->nb_threads;
}

static int process_options(AVFilterContext *ctx, AVDictionary **options,
                           const char *args)
{
    const AVOption *o = NULL;
    int ret, count = 0;
    char *av_uninit(parsed_key), *av_uninit(value);
    const char *key;
    int offset= -1;

    if (!args)
        return 0;

    while (*args) {
        const char *shorthand = NULL;

        o = av_opt_next(ctx->priv, o);
        if (o) {
            if (o->type == AV_OPT_TYPE_CONST || o->offset == offset)
                continue;
            offset = o->offset;
            shorthand = o->name;
        }

        ret = av_opt_get_key_value(&args, "=", ":",
                                   shorthand ? AV_OPT_FLAG_IMPLICIT_KEY : 0,
                                   &parsed_key, &value);
        if (ret < 0) {
            if (ret == AVERROR(EINVAL))
                av_log(ctx, AV_LOG_ERROR, "No option name near '%s'\n", args);
            else
                av_log(ctx, AV_LOG_ERROR, "Unable to parse '%s': %s\n", args,
                       av_err2str(ret));
            return ret;
        }
        if (*args)
            args++;
        if (parsed_key) {
            key = parsed_key;
            while ((o = av_opt_next(ctx->priv, o))); /* discard all remaining shorthand */
        } else {
            key = shorthand;
        }

        av_log(ctx, AV_LOG_DEBUG, "Setting '%s' to value '%s'\n", key, value);

        if (av_opt_find(ctx, key, NULL, 0, 0)) {
            ret = av_opt_set(ctx, key, value, 0);
            if (ret < 0) {
                av_free(value);
                av_free(parsed_key);
                return ret;
            }
        } else {
        av_dict_set(options, key, value, 0);
        if ((ret = av_opt_set(ctx->priv, key, value, AV_OPT_SEARCH_CHILDREN)) < 0) {
            if (!av_opt_find(ctx->priv, key, NULL, 0, AV_OPT_SEARCH_CHILDREN | AV_OPT_SEARCH_FAKE_OBJ)) {
            if (ret == AVERROR_OPTION_NOT_FOUND)
                av_log(ctx, AV_LOG_ERROR, "Option '%s' not found\n", key);
            av_free(value);
            av_free(parsed_key);
            return ret;
            }
        }
        }

        av_free(value);
        av_free(parsed_key);
        count++;
    }

    if (ctx->enable_str) {
        ret = set_enable_expr(ctx, ctx->enable_str);
        if (ret < 0)
            return ret;
    }
    return count;
}

int ff_filter_process_command(AVFilterContext *ctx, const char *cmd,
                              const char *arg, char *res, int res_len, int flags)
{
    const AVOption *o;

    if (!ctx->filter->priv_class)
        return 0;
    o = av_opt_find2(ctx->priv, cmd, NULL, AV_OPT_FLAG_RUNTIME_PARAM | AV_OPT_FLAG_FILTERING_PARAM, AV_OPT_SEARCH_CHILDREN, NULL);
    if (!o)
        return AVERROR(ENOSYS);
    return av_opt_set(ctx->priv, cmd, arg, 0);
}

int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options)
{
    int ret = 0;

    ret = av_opt_set_dict(ctx, options);
    if (ret < 0) {
        av_log(ctx, AV_LOG_ERROR, "Error applying generic filter options.\n");
        return ret;
    }

    if (ctx->filter->flags & AVFILTER_FLAG_SLICE_THREADS &&
        ctx->thread_type & ctx->graph->thread_type & AVFILTER_THREAD_SLICE &&
        ctx->graph->internal->thread_execute) {
        ctx->thread_type       = AVFILTER_THREAD_SLICE;
        ctx->internal->execute = ctx->graph->internal->thread_execute;
    } else {
        ctx->thread_type = 0;
    }

    if (ctx->filter->priv_class) {
        ret = av_opt_set_dict2(ctx->priv, options, AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(ctx, AV_LOG_ERROR, "Error applying options to the filter.\n");
            return ret;
        }
    }

    if (ctx->filter->init_opaque)
        ret = ctx->filter->init_opaque(ctx, NULL);
    else if (ctx->filter->init)
        ret = ctx->filter->init(ctx);
    else if (ctx->filter->init_dict)
        ret = ctx->filter->init_dict(ctx, options);

    return ret;
}

int avfilter_init_str(AVFilterContext *filter, const char *args)
{
    AVDictionary *options = NULL;
    AVDictionaryEntry *e;
    int ret = 0;

    if (args && *args) {
        if (!filter->filter->priv_class) {
            av_log(filter, AV_LOG_ERROR, "This filter does not take any "
                   "options, but options were provided: %s.\n", args);
            return AVERROR(EINVAL);
        }

#if FF_API_OLD_FILTER_OPTS_ERROR
            if (   !strcmp(filter->filter->name, "format")     ||
                   !strcmp(filter->filter->name, "noformat")   ||
                   !strcmp(filter->filter->name, "frei0r")     ||
                   !strcmp(filter->filter->name, "frei0r_src") ||
                   !strcmp(filter->filter->name, "ocv")        ||
                   !strcmp(filter->filter->name, "pan")        ||
                   !strcmp(filter->filter->name, "pp")         ||
                   !strcmp(filter->filter->name, "aevalsrc")) {
            /* a hack for compatibility with the old syntax
             * replace colons with |s */
            char *copy = av_strdup(args);
            char *p    = copy;
            int nb_leading = 0; // number of leading colons to skip
            int deprecated = 0;

            if (!copy) {
                ret = AVERROR(ENOMEM);
                goto fail;
            }

            if (!strcmp(filter->filter->name, "frei0r") ||
                !strcmp(filter->filter->name, "ocv"))
                nb_leading = 1;
            else if (!strcmp(filter->filter->name, "frei0r_src"))
                nb_leading = 3;

            while (nb_leading--) {
                p = strchr(p, ':');
                if (!p) {
                    p = copy + strlen(copy);
                    break;
                }
                p++;
            }

            deprecated = strchr(p, ':') != NULL;

            if (!strcmp(filter->filter->name, "aevalsrc")) {
                deprecated = 0;
                while ((p = strchr(p, ':')) && p[1] != ':') {
                    const char *epos = strchr(p + 1, '=');
                    const char *spos = strchr(p + 1, ':');
                    const int next_token_is_opt = epos && (!spos || epos < spos);
                    if (next_token_is_opt) {
                        p++;
                        break;
                    }
                    /* next token does not contain a '=', assume a channel expression */
                    deprecated = 1;
                    *p++ = '|';
                }
                if (p && *p == ':') { // double sep '::' found
                    deprecated = 1;
                    memmove(p, p + 1, strlen(p));
                }
            } else
            while ((p = strchr(p, ':')))
                *p++ = '|';

            if (deprecated) {
                av_log(filter, AV_LOG_ERROR, "This syntax is deprecated. Use "
                       "'|' to separate the list items ('%s' instead of '%s')\n",
                       copy, args);
                ret = AVERROR(EINVAL);
            } else {
                ret = process_options(filter, &options, copy);
            }
            av_freep(&copy);

            if (ret < 0)
                goto fail;
        } else
#endif
        {
            ret = process_options(filter, &options, args);
            if (ret < 0)
                goto fail;
        }
    }

    ret = avfilter_init_dict(filter, &options);
    if (ret < 0)
        goto fail;

    if ((e = av_dict_get(options, "", NULL, AV_DICT_IGNORE_SUFFIX))) {
        av_log(filter, AV_LOG_ERROR, "No such option: %s.\n", e->key);
        ret = AVERROR_OPTION_NOT_FOUND;
        goto fail;
    }

fail:
    av_dict_free(&options);

    return ret;
}

const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx)
{
    return pads[pad_idx].name;
}

enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx)
{
    return pads[pad_idx].type;
}

static int default_filter_frame(AVFilterLink *link, AVFrame *frame)
{
    return ff_filter_frame(link->dst->outputs[0], frame);
}

static int ff_filter_frame_framed(AVFilterLink *link, AVFrame *frame)
{
    int (*filter_frame)(AVFilterLink *, AVFrame *);
    AVFilterContext *dstctx = link->dst;
    AVFilterPad *dst = link->dstpad;
    int ret;

    if (!(filter_frame = dst->filter_frame))
        filter_frame = default_filter_frame;

    if (dst->needs_writable) {
        ret = ff_inlink_make_frame_writable(link, &frame);
        if (ret < 0)
            goto fail;
    }

    ff_inlink_process_commands(link, frame);
    dstctx->is_disabled = !ff_inlink_evaluate_timeline_at_frame(link, frame);

    if (dstctx->is_disabled &&
        (dstctx->filter->flags & AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC))
        filter_frame = default_filter_frame;
    ret = filter_frame(link, frame);
    link->frame_count_out++;
    return ret;

fail:
    av_frame_free(&frame);
    return ret;
}

int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
{
    int ret;
    FF_TPRINTF_START(NULL, filter_frame); ff_tlog_link(NULL, link, 1); ff_tlog(NULL, " "); ff_tlog_ref(NULL, frame, 1);

    /* Consistency checks */
    if (link->type == AVMEDIA_TYPE_VIDEO) {
        if (strcmp(link->dst->filter->name, "buffersink") &&
            strcmp(link->dst->filter->name, "format") &&
            strcmp(link->dst->filter->name, "idet") &&
            strcmp(link->dst->filter->name, "null") &&
            strcmp(link->dst->filter->name, "scale")) {
            av_assert1(frame->format                 == link->format);
            av_assert1(frame->width               == link->w);
            av_assert1(frame->height               == link->h);
        }
    } else {
        if (frame->format != link->format) {
            av_log(link->dst, AV_LOG_ERROR, "Format change is not supported\n");
            goto error;
        }
        if (frame->channels != link->channels) {
            av_log(link->dst, AV_LOG_ERROR, "Channel count change is not supported\n");
            goto error;
        }
        if (frame->channel_layout != link->channel_layout) {
            av_log(link->dst, AV_LOG_ERROR, "Channel layout change is not supported\n");
            goto error;
        }
        if (frame->sample_rate != link->sample_rate) {
            av_log(link->dst, AV_LOG_ERROR, "Sample rate change is not supported\n");
            goto error;
        }
    }

    link->frame_blocked_in = link->frame_wanted_out = 0;
    link->frame_count_in++;
    filter_unblock(link->dst);
    ret = ff_framequeue_add(&link->fifo, frame);
    if (ret < 0) {
        av_frame_free(&frame);
        return ret;
    }
    ff_filter_set_ready(link->dst, 300);
    return 0;

error:
    av_frame_free(&frame);
    return AVERROR_PATCHWELCOME;
}

static int samples_ready(AVFilterLink *link, unsigned min)
{
    return ff_framequeue_queued_frames(&link->fifo) &&
           (ff_framequeue_queued_samples(&link->fifo) >= min ||
            link->status_in);
}

static int take_samples(AVFilterLink *link, unsigned min, unsigned max,
                        AVFrame **rframe)
{
    AVFrame *frame0, *frame, *buf;
    unsigned nb_samples, nb_frames, i, p;
    int ret;

    /* Note: this function relies on no format changes and must only be
       called with enough samples. */
    av_assert1(samples_ready(link, link->min_samples));
    frame0 = frame = ff_framequeue_peek(&link->fifo, 0);
    if (!link->fifo.samples_skipped && frame->nb_samples >= min && frame->nb_samples <= max) {
        *rframe = ff_framequeue_take(&link->fifo);
        return 0;
    }
    nb_frames = 0;
    nb_samples = 0;
    while (1) {
        if (nb_samples + frame->nb_samples > max) {
            if (nb_samples < min)
                nb_samples = max;
            break;
        }
        nb_samples += frame->nb_samples;
        nb_frames++;
        if (nb_frames == ff_framequeue_queued_frames(&link->fifo))
            break;
        frame = ff_framequeue_peek(&link->fifo, nb_frames);
    }

    buf = ff_get_audio_buffer(link, nb_samples);
    if (!buf)
        return AVERROR(ENOMEM);
    ret = av_frame_copy_props(buf, frame0);
    if (ret < 0) {
        av_frame_free(&buf);
        return ret;
    }
    buf->pts = frame0->pts;

    p = 0;
    for (i = 0; i < nb_frames; i++) {
        frame = ff_framequeue_take(&link->fifo);
        av_samples_copy(buf->extended_data, frame->extended_data, p, 0,
                        frame->nb_samples, link->channels, link->format);
        p += frame->nb_samples;
        av_frame_free(&frame);
    }
    if (p < nb_samples) {
        unsigned n = nb_samples - p;
        frame = ff_framequeue_peek(&link->fifo, 0);
        av_samples_copy(buf->extended_data, frame->extended_data, p, 0, n,
                        link->channels, link->format);
        ff_framequeue_skip_samples(&link->fifo, n, link->time_base);
    }

    *rframe = buf;
    return 0;
}

static int ff_filter_frame_to_filter(AVFilterLink *link)
{
    AVFrame *frame = NULL;
    AVFilterContext *dst = link->dst;
    int ret;

    av_assert1(ff_framequeue_queued_frames(&link->fifo));
    ret = link->min_samples ?
          ff_inlink_consume_samples(link, link->min_samples, link->max_samples, &frame) :
          ff_inlink_consume_frame(link, &frame);
    av_assert1(ret);
    if (ret < 0) {
        av_assert1(!frame);
        return ret;
    }
    /* The filter will soon have received a new frame, that may allow it to
       produce one or more: unblock its outputs. */
    filter_unblock(dst);
    /* AVFilterPad.filter_frame() expect frame_count_out to have the value
       before the frame; ff_filter_frame_framed() will re-increment it. */
    link->frame_count_out--;
    ret = ff_filter_frame_framed(link, frame);
    if (ret < 0 && ret != link->status_out) {
        ff_avfilter_link_set_out_status(link, ret, AV_NOPTS_VALUE);
    } else {
        /* Run once again, to see if several frames were available, or if
           the input status has also changed, or any other reason. */
        ff_filter_set_ready(dst, 300);
    }
    return ret;
}

static int forward_status_change(AVFilterContext *filter, AVFilterLink *in)
{
    unsigned out = 0, progress = 0;
    int ret;

    av_assert0(!in->status_out);
    if (!filter->nb_outputs) {
        /* not necessary with the current API and sinks */
        return 0;
    }
    while (!in->status_out) {
        if (!filter->outputs[out]->status_in) {
            progress++;
            ret = ff_request_frame_to_filter(filter->outputs[out]);
            if (ret < 0)
                return ret;
        }
        if (++out == filter->nb_outputs) {
            if (!progress) {
                /* Every output already closed: input no longer interesting
                   (example: overlay in shortest mode, other input closed). */
                ff_avfilter_link_set_out_status(in, in->status_in, in->status_in_pts);
                return 0;
            }
            progress = 0;
            out = 0;
        }
    }
    ff_filter_set_ready(filter, 200);
    return 0;
}

static int ff_filter_activate_default(AVFilterContext *filter)
{
    unsigned i;

    for (i = 0; i < filter->nb_inputs; i++) {
        if (samples_ready(filter->inputs[i], filter->inputs[i]->min_samples)) {
            return ff_filter_frame_to_filter(filter->inputs[i]);
        }
    }
    for (i = 0; i < filter->nb_inputs; i++) {
        if (filter->inputs[i]->status_in && !filter->inputs[i]->status_out) {
            av_assert1(!ff_framequeue_queued_frames(&filter->inputs[i]->fifo));
            return forward_status_change(filter, filter->inputs[i]);
        }
    }
    for (i = 0; i < filter->nb_outputs; i++) {
        if (filter->outputs[i]->frame_wanted_out &&
            !filter->outputs[i]->frame_blocked_in) {
            return ff_request_frame_to_filter(filter->outputs[i]);
        }
    }
    return FFERROR_NOT_READY;
}

/*
   Filter scheduling and activation

   When a filter is activated, it must:
   - if possible, output a frame;
   - else, if relevant, forward the input status change;
   - else, check outputs for wanted frames and forward the requests.

   The following AVFilterLink fields are used for activation:

   - frame_wanted_out:

     This field indicates if a frame is needed on this input of the
     destination filter. A positive value indicates that a frame is needed
     to process queued frames or internal data or to satisfy the
     application; a zero value indicates that a frame is not especially
     needed but could be processed anyway; a negative value indicates that a
     frame would just be queued.

     It is set by filters using ff_request_frame() or ff_request_no_frame(),
     when requested by the application through a specific API or when it is
     set on one of the outputs.

     It is cleared when a frame is sent from the source using
     ff_filter_frame().

     It is also cleared when a status change is sent from the source using
     ff_avfilter_link_set_in_status().

   - frame_blocked_in:

     This field means that the source filter can not generate a frame as is.
     Its goal is to avoid repeatedly calling the request_frame() method on
     the same link.

     It is set by the framework on all outputs of a filter before activating it.

     It is automatically cleared by ff_filter_frame().

     It is also automatically cleared by ff_avfilter_link_set_in_status().

     It is also cleared on all outputs (using filter_unblock()) when
     something happens on an input: processing a frame or changing the
     status.

   - fifo:

     Contains the frames queued on a filter input. If it contains frames and
     frame_wanted_out is not set, then the filter can be activated. If that
     result in the filter not able to use these frames, the filter must set
     frame_wanted_out to ask for more frames.

   - status_in and status_in_pts:

     Status (EOF or error code) of the link and timestamp of the status
     change (in link time base, same as frames) as seen from the input of
     the link. The status change is considered happening after the frames
     queued in fifo.

     It is set by the source filter using ff_avfilter_link_set_in_status().

   - status_out:

     Status of the link as seen from the output of the link. The status
     change is considered having already happened.

     It is set by the destination filter using
     ff_avfilter_link_set_out_status().

   Filters are activated according to the ready field, set using the
   ff_filter_set_ready(). Eventually, a priority queue will be used.
   ff_filter_set_ready() is called whenever anything could cause progress to
   be possible. Marking a filter ready when it is not is not a problem,
   except for the small overhead it causes.

   Conditions that cause a filter to be marked ready are:

   - frames added on an input link;

   - changes in the input or output status of an input link;

   - requests for a frame on an output link;

   - after any actual processing using the legacy methods (filter_frame(),
     and request_frame() to acknowledge status changes), to run once more
     and check if enough input was present for several frames.

   Examples of scenarios to consider:

   - buffersrc: activate if frame_wanted_out to notify the application;
     activate when the application adds a frame to push it immediately.

   - testsrc: activate only if frame_wanted_out to produce and push a frame.

   - concat (not at stitch points): can process a frame on any output.
     Activate if frame_wanted_out on output to forward on the corresponding
     input. Activate when a frame is present on input to process it
     immediately.

   - framesync: needs at least one frame on each input; extra frames on the
     wrong input will accumulate. When a frame is first added on one input,
     set frame_wanted_out<0 on it to avoid getting more (would trigger
     testsrc) and frame_wanted_out>0 on the other to allow processing it.

   Activation of old filters:

   In order to activate a filter implementing the legacy filter_frame() and
   request_frame() methods, perform the first possible of the following
   actions:

   - If an input has frames in fifo and frame_wanted_out == 0, dequeue a
     frame and call filter_frame().

     Rationale: filter frames as soon as possible instead of leaving them
     queued; frame_wanted_out < 0 is not possible since the old API does not
     set it nor provides any similar feedback; frame_wanted_out > 0 happens
     when min_samples > 0 and there are not enough samples queued.

   - If an input has status_in set but not status_out, try to call
     request_frame() on one of the outputs in the hope that it will trigger
     request_frame() on the input with status_in and acknowledge it. This is
     awkward and fragile, filters with several inputs or outputs should be
     updated to direct activation as soon as possible.

   - If an output has frame_wanted_out > 0 and not frame_blocked_in, call
     request_frame().

     Rationale: checking frame_blocked_in is necessary to avoid requesting
     repeatedly on a blocked input if another is not blocked (example:
     [buffersrc1][testsrc1][buffersrc2][testsrc2]concat=v=2).

     TODO: respect needs_fifo and remove auto-inserted fifos.

 */

int ff_filter_activate(AVFilterContext *filter)
{
    int ret;

    /* Generic timeline support is not yet implemented but should be easy */
    av_assert1(!(filter->filter->flags & AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC &&
                 filter->filter->activate));
    filter->ready = 0;
    ret = filter->filter->activate ? filter->filter->activate(filter) :
          ff_filter_activate_default(filter);
    if (ret == FFERROR_NOT_READY)
        ret = 0;
    return ret;
}

int ff_inlink_acknowledge_status(AVFilterLink *link, int *rstatus, int64_t *rpts)
{
    *rpts = link->current_pts;
    if (ff_framequeue_queued_frames(&link->fifo))
        return *rstatus = 0;
    if (link->status_out)
        return *rstatus = link->status_out;
    if (!link->status_in)
        return *rstatus = 0;
    *rstatus = link->status_out = link->status_in;
    ff_update_link_current_pts(link, link->status_in_pts);
    *rpts = link->current_pts;
    return 1;
}

size_t ff_inlink_queued_frames(AVFilterLink *link)
{
    return ff_framequeue_queued_frames(&link->fifo);
}

int ff_inlink_check_available_frame(AVFilterLink *link)
{
    return ff_framequeue_queued_frames(&link->fifo) > 0;
}

int ff_inlink_queued_samples(AVFilterLink *link)
{
    return ff_framequeue_queued_samples(&link->fifo);
}

int ff_inlink_check_available_samples(AVFilterLink *link, unsigned min)
{
    uint64_t samples = ff_framequeue_queued_samples(&link->fifo);
    av_assert1(min);
    return samples >= min || (link->status_in && samples);
}

static void consume_update(AVFilterLink *link, const AVFrame *frame)
{
    ff_update_link_current_pts(link, frame->pts);
    ff_inlink_process_commands(link, frame);
    link->dst->is_disabled = !ff_inlink_evaluate_timeline_at_frame(link, frame);
    link->frame_count_out++;
}

int ff_inlink_consume_frame(AVFilterLink *link, AVFrame **rframe)
{
    AVFrame *frame;

    *rframe = NULL;
    if (!ff_inlink_check_available_frame(link))
        return 0;

    if (link->fifo.samples_skipped) {
        frame = ff_framequeue_peek(&link->fifo, 0);
        return ff_inlink_consume_samples(link, frame->nb_samples, frame->nb_samples, rframe);
    }

    frame = ff_framequeue_take(&link->fifo);
    consume_update(link, frame);
    *rframe = frame;
    return 1;
}

int ff_inlink_consume_samples(AVFilterLink *link, unsigned min, unsigned max,
                            AVFrame **rframe)
{
    AVFrame *frame;
    int ret;

    av_assert1(min);
    *rframe = NULL;
    if (!ff_inlink_check_available_samples(link, min))
        return 0;
    if (link->status_in)
        min = FFMIN(min, ff_framequeue_queued_samples(&link->fifo));
    ret = take_samples(link, min, max, &frame);
    if (ret < 0)
        return ret;
    consume_update(link, frame);
    *rframe = frame;
    return 1;
}

AVFrame *ff_inlink_peek_frame(AVFilterLink *link, size_t idx)
{
    return ff_framequeue_peek(&link->fifo, idx);
}

int ff_inlink_make_frame_writable(AVFilterLink *link, AVFrame **rframe)
{
    AVFrame *frame = *rframe;
    AVFrame *out;
    int ret;

    if (av_frame_is_writable(frame))
        return 0;
    av_log(link->dst, AV_LOG_DEBUG, "Copying data in avfilter.\n");

    switch (link->type) {
    case AVMEDIA_TYPE_VIDEO:
        out = ff_get_video_buffer(link, link->w, link->h);
        break;
    case AVMEDIA_TYPE_AUDIO:
        out = ff_get_audio_buffer(link, frame->nb_samples);
        break;
    default:
        return AVERROR(EINVAL);
    }
    if (!out)
        return AVERROR(ENOMEM);

    ret = av_frame_copy_props(out, frame);
    if (ret < 0) {
        av_frame_free(&out);
        return ret;
    }

    switch (link->type) {
    case AVMEDIA_TYPE_VIDEO:
        av_image_copy(out->data, out->linesize, (const uint8_t **)frame->data, frame->linesize,
                      frame->format, frame->width, frame->height);
        break;
    case AVMEDIA_TYPE_AUDIO:
        av_samples_copy(out->extended_data, frame->extended_data,
                        0, 0, frame->nb_samples,
                        frame->channels,
                        frame->format);
        break;
    default:
        av_assert0(!"reached");
    }

    av_frame_free(&frame);
    *rframe = out;
    return 0;
}

int ff_inlink_process_commands(AVFilterLink *link, const AVFrame *frame)
{
    AVFilterCommand *cmd = link->dst->command_queue;

    while(cmd && cmd->time <= frame->pts * av_q2d(link->time_base)){
        av_log(link->dst, AV_LOG_DEBUG,
               "Processing command time:%f command:%s arg:%s\n",
               cmd->time, cmd->command, cmd->arg);
        avfilter_process_command(link->dst, cmd->command, cmd->arg, 0, 0, cmd->flags);
        ff_command_queue_pop(link->dst);
        cmd= link->dst->command_queue;
    }
    return 0;
}

int ff_inlink_evaluate_timeline_at_frame(AVFilterLink *link, const AVFrame *frame)
{
    AVFilterContext *dstctx = link->dst;
    int64_t pts = frame->pts;
    int64_t pos = frame->pkt_pos;

    if (!dstctx->enable_str)
        return 1;

    dstctx->var_values[VAR_N] = link->frame_count_out;
    dstctx->var_values[VAR_T] = pts == AV_NOPTS_VALUE ? NAN : pts * av_q2d(link->time_base);
    dstctx->var_values[VAR_W] = link->w;
    dstctx->var_values[VAR_H] = link->h;
    dstctx->var_values[VAR_POS] = pos == -1 ? NAN : pos;

    return fabs(av_expr_eval(dstctx->enable, dstctx->var_values, NULL)) >= 0.5;
}

void ff_inlink_request_frame(AVFilterLink *link)
{
    av_assert1(!link->status_in);
    av_assert1(!link->status_out);
    link->frame_wanted_out = 1;
    ff_filter_set_ready(link->src, 100);
}

void ff_inlink_set_status(AVFilterLink *link, int status)
{
    if (link->status_out)
        return;
    link->frame_wanted_out = 0;
    link->frame_blocked_in = 0;
    ff_avfilter_link_set_out_status(link, status, AV_NOPTS_VALUE);
    while (ff_framequeue_queued_frames(&link->fifo)) {
           AVFrame *frame = ff_framequeue_take(&link->fifo);
           av_frame_free(&frame);
    }
    if (!link->status_in)
        link->status_in = status;
}

int ff_outlink_get_status(AVFilterLink *link)
{
    return link->status_in;
}

const AVClass *avfilter_get_class(void)
{
    return &avfilter_class;
}

int ff_filter_init_hw_frames(AVFilterContext *avctx, AVFilterLink *link,
                             int default_pool_size)
{
    AVHWFramesContext *frames;

    // Must already be set by caller.
    av_assert0(link->hw_frames_ctx);

    frames = (AVHWFramesContext*)link->hw_frames_ctx->data;

    if (frames->initial_pool_size == 0) {
        // Dynamic allocation is necessarily supported.
    } else if (avctx->extra_hw_frames >= 0) {
        frames->initial_pool_size += avctx->extra_hw_frames;
    } else {
        frames->initial_pool_size = default_pool_size;
    }

    return 0;
}