1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
|
/*
* Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
/*
* The core AEC algorithm, which is presented with time-aligned signals.
*/
#include "webrtc/modules/audio_processing/aec/aec_core.h"
#ifdef WEBRTC_AEC_DEBUG_DUMP
#include <stdio.h>
#endif
#include <assert.h>
#include <math.h>
#include <stddef.h> // size_t
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include "webrtc/common_audio/ring_buffer.h"
#include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
#include "webrtc/modules/audio_processing/aec/aec_common.h"
#include "webrtc/modules/audio_processing/aec/aec_core_internal.h"
#include "webrtc/modules/audio_processing/aec/aec_rdft.h"
#include "webrtc/modules/audio_processing/utility/delay_estimator_wrapper.h"
#include "webrtc/system_wrappers/interface/cpu_features_wrapper.h"
#include "webrtc/typedefs.h"
extern int AECDebug();
extern uint32_t AECDebugMaxSize();
extern void AECDebugEnable(uint32_t enable);
extern void AECDebugFilenameBase(char *buffer, size_t size);
static void OpenCoreDebugFiles(AecCore* aec, int *instance_count);
// Buffer size (samples)
static const size_t kBufSizePartitions = 250; // 1 second of audio in 16 kHz.
// Metrics
static const int subCountLen = 4;
static const int countLen = 50;
static const int kDelayMetricsAggregationWindow = 1250; // 5 seconds at 16 kHz.
// Quantities to control H band scaling for SWB input
static const int flagHbandCn = 1; // flag for adding comfort noise in H band
static const float cnScaleHband =
(float)0.4; // scale for comfort noise in H band
// Initial bin for averaging nlp gain in low band
static const int freqAvgIc = PART_LEN / 2;
// Matlab code to produce table:
// win = sqrt(hanning(63)); win = [0 ; win(1:32)];
// fprintf(1, '\t%.14f, %.14f, %.14f,\n', win);
ALIGN16_BEG const float ALIGN16_END WebRtcAec_sqrtHanning[65] = {
0.00000000000000f, 0.02454122852291f, 0.04906767432742f, 0.07356456359967f,
0.09801714032956f, 0.12241067519922f, 0.14673047445536f, 0.17096188876030f,
0.19509032201613f, 0.21910124015687f, 0.24298017990326f, 0.26671275747490f,
0.29028467725446f, 0.31368174039889f, 0.33688985339222f, 0.35989503653499f,
0.38268343236509f, 0.40524131400499f, 0.42755509343028f, 0.44961132965461f,
0.47139673682600f, 0.49289819222978f, 0.51410274419322f, 0.53499761988710f,
0.55557023301960f, 0.57580819141785f, 0.59569930449243f, 0.61523159058063f,
0.63439328416365f, 0.65317284295378f, 0.67155895484702f, 0.68954054473707f,
0.70710678118655f, 0.72424708295147f, 0.74095112535496f, 0.75720884650648f,
0.77301045336274f, 0.78834642762661f, 0.80320753148064f, 0.81758481315158f,
0.83146961230255f, 0.84485356524971f, 0.85772861000027f, 0.87008699110871f,
0.88192126434835f, 0.89322430119552f, 0.90398929312344f, 0.91420975570353f,
0.92387953251129f, 0.93299279883474f, 0.94154406518302f, 0.94952818059304f,
0.95694033573221f, 0.96377606579544f, 0.97003125319454f, 0.97570213003853f,
0.98078528040323f, 0.98527764238894f, 0.98917650996478f, 0.99247953459871f,
0.99518472667220f, 0.99729045667869f, 0.99879545620517f, 0.99969881869620f,
1.00000000000000f};
// Matlab code to produce table:
// weightCurve = [0 ; 0.3 * sqrt(linspace(0,1,64))' + 0.1];
// fprintf(1, '\t%.4f, %.4f, %.4f, %.4f, %.4f, %.4f,\n', weightCurve);
ALIGN16_BEG const float ALIGN16_END WebRtcAec_weightCurve[65] = {
0.0000f, 0.1000f, 0.1378f, 0.1535f, 0.1655f, 0.1756f, 0.1845f, 0.1926f,
0.2000f, 0.2069f, 0.2134f, 0.2195f, 0.2254f, 0.2309f, 0.2363f, 0.2414f,
0.2464f, 0.2512f, 0.2558f, 0.2604f, 0.2648f, 0.2690f, 0.2732f, 0.2773f,
0.2813f, 0.2852f, 0.2890f, 0.2927f, 0.2964f, 0.3000f, 0.3035f, 0.3070f,
0.3104f, 0.3138f, 0.3171f, 0.3204f, 0.3236f, 0.3268f, 0.3299f, 0.3330f,
0.3360f, 0.3390f, 0.3420f, 0.3449f, 0.3478f, 0.3507f, 0.3535f, 0.3563f,
0.3591f, 0.3619f, 0.3646f, 0.3673f, 0.3699f, 0.3726f, 0.3752f, 0.3777f,
0.3803f, 0.3828f, 0.3854f, 0.3878f, 0.3903f, 0.3928f, 0.3952f, 0.3976f,
0.4000f};
// Matlab code to produce table:
// overDriveCurve = [sqrt(linspace(0,1,65))' + 1];
// fprintf(1, '\t%.4f, %.4f, %.4f, %.4f, %.4f, %.4f,\n', overDriveCurve);
ALIGN16_BEG const float ALIGN16_END WebRtcAec_overDriveCurve[65] = {
1.0000f, 1.1250f, 1.1768f, 1.2165f, 1.2500f, 1.2795f, 1.3062f, 1.3307f,
1.3536f, 1.3750f, 1.3953f, 1.4146f, 1.4330f, 1.4507f, 1.4677f, 1.4841f,
1.5000f, 1.5154f, 1.5303f, 1.5449f, 1.5590f, 1.5728f, 1.5863f, 1.5995f,
1.6124f, 1.6250f, 1.6374f, 1.6495f, 1.6614f, 1.6731f, 1.6847f, 1.6960f,
1.7071f, 1.7181f, 1.7289f, 1.7395f, 1.7500f, 1.7603f, 1.7706f, 1.7806f,
1.7906f, 1.8004f, 1.8101f, 1.8197f, 1.8292f, 1.8385f, 1.8478f, 1.8570f,
1.8660f, 1.8750f, 1.8839f, 1.8927f, 1.9014f, 1.9100f, 1.9186f, 1.9270f,
1.9354f, 1.9437f, 1.9520f, 1.9601f, 1.9682f, 1.9763f, 1.9843f, 1.9922f,
2.0000f};
// Delay Agnostic AEC parameters, still under development and may change.
static const float kDelayQualityThresholdMax = 0.07f;
static const float kDelayQualityThresholdMin = 0.01f;
static const int kInitialShiftOffset = 5;
#if !defined(WEBRTC_ANDROID) && !defined(WEBRTC_GONK)
static const int kDelayCorrectionStart = 1500; // 10 ms chunks
#endif
// Target suppression levels for nlp modes.
// log{0.001, 0.00001, 0.00000001}
static const float kTargetSupp[3] = {-6.9f, -11.5f, -18.4f};
// Two sets of parameters, one for the extended filter mode.
static const float kExtendedMinOverDrive[3] = {3.0f, 6.0f, 15.0f};
static const float kNormalMinOverDrive[3] = {1.0f, 2.0f, 5.0f};
const float WebRtcAec_kExtendedSmoothingCoefficients[2][2] = {{0.9f, 0.1f},
{0.92f, 0.08f}};
const float WebRtcAec_kNormalSmoothingCoefficients[2][2] = {{0.9f, 0.1f},
{0.93f, 0.07f}};
// Number of partitions forming the NLP's "preferred" bands.
enum {
kPrefBandSize = 24
};
#ifdef WEBRTC_AEC_DEBUG_DUMP
extern int webrtc_aec_instance_count;
#endif
WebRtcAecFilterFar WebRtcAec_FilterFar;
WebRtcAecScaleErrorSignal WebRtcAec_ScaleErrorSignal;
WebRtcAecFilterAdaptation WebRtcAec_FilterAdaptation;
WebRtcAecOverdriveAndSuppress WebRtcAec_OverdriveAndSuppress;
WebRtcAecComfortNoise WebRtcAec_ComfortNoise;
WebRtcAecSubBandCoherence WebRtcAec_SubbandCoherence;
__inline static float MulRe(float aRe, float aIm, float bRe, float bIm) {
return aRe * bRe - aIm * bIm;
}
__inline static float MulIm(float aRe, float aIm, float bRe, float bIm) {
return aRe * bIm + aIm * bRe;
}
static int CmpFloat(const void* a, const void* b) {
const float* da = (const float*)a;
const float* db = (const float*)b;
return (*da > *db) - (*da < *db);
}
static void FilterFar(AecCore* aec, float yf[2][PART_LEN1]) {
int i;
for (i = 0; i < aec->num_partitions; i++) {
int j;
int xPos = (i + aec->xfBufBlockPos) * PART_LEN1;
int pos = i * PART_LEN1;
// Check for wrap
if (i + aec->xfBufBlockPos >= aec->num_partitions) {
xPos -= aec->num_partitions * (PART_LEN1);
}
for (j = 0; j < PART_LEN1; j++) {
yf[0][j] += MulRe(aec->xfBuf[0][xPos + j],
aec->xfBuf[1][xPos + j],
aec->wfBuf[0][pos + j],
aec->wfBuf[1][pos + j]);
yf[1][j] += MulIm(aec->xfBuf[0][xPos + j],
aec->xfBuf[1][xPos + j],
aec->wfBuf[0][pos + j],
aec->wfBuf[1][pos + j]);
}
}
}
static void ScaleErrorSignal(AecCore* aec, float ef[2][PART_LEN1]) {
const float mu = aec->extended_filter_enabled ? kExtendedMu : aec->normal_mu;
const float error_threshold = aec->extended_filter_enabled
? kExtendedErrorThreshold
: aec->normal_error_threshold;
int i;
float abs_ef;
for (i = 0; i < (PART_LEN1); i++) {
ef[0][i] /= (aec->xPow[i] + 1e-10f);
ef[1][i] /= (aec->xPow[i] + 1e-10f);
abs_ef = sqrtf(ef[0][i] * ef[0][i] + ef[1][i] * ef[1][i]);
if (abs_ef > error_threshold) {
abs_ef = error_threshold / (abs_ef + 1e-10f);
ef[0][i] *= abs_ef;
ef[1][i] *= abs_ef;
}
// Stepsize factor
ef[0][i] *= mu;
ef[1][i] *= mu;
}
}
// Time-unconstrined filter adaptation.
// TODO(andrew): consider for a low-complexity mode.
// static void FilterAdaptationUnconstrained(AecCore* aec, float *fft,
// float ef[2][PART_LEN1]) {
// int i, j;
// for (i = 0; i < aec->num_partitions; i++) {
// int xPos = (i + aec->xfBufBlockPos)*(PART_LEN1);
// int pos;
// // Check for wrap
// if (i + aec->xfBufBlockPos >= aec->num_partitions) {
// xPos -= aec->num_partitions * PART_LEN1;
// }
//
// pos = i * PART_LEN1;
//
// for (j = 0; j < PART_LEN1; j++) {
// aec->wfBuf[0][pos + j] += MulRe(aec->xfBuf[0][xPos + j],
// -aec->xfBuf[1][xPos + j],
// ef[0][j], ef[1][j]);
// aec->wfBuf[1][pos + j] += MulIm(aec->xfBuf[0][xPos + j],
// -aec->xfBuf[1][xPos + j],
// ef[0][j], ef[1][j]);
// }
// }
//}
static void FilterAdaptation(AecCore* aec, float* fft, float ef[2][PART_LEN1]) {
int i, j;
for (i = 0; i < aec->num_partitions; i++) {
int xPos = (i + aec->xfBufBlockPos) * (PART_LEN1);
int pos;
// Check for wrap
if (i + aec->xfBufBlockPos >= aec->num_partitions) {
xPos -= aec->num_partitions * PART_LEN1;
}
pos = i * PART_LEN1;
for (j = 0; j < PART_LEN; j++) {
fft[2 * j] = MulRe(aec->xfBuf[0][xPos + j],
-aec->xfBuf[1][xPos + j],
ef[0][j],
ef[1][j]);
fft[2 * j + 1] = MulIm(aec->xfBuf[0][xPos + j],
-aec->xfBuf[1][xPos + j],
ef[0][j],
ef[1][j]);
}
fft[1] = MulRe(aec->xfBuf[0][xPos + PART_LEN],
-aec->xfBuf[1][xPos + PART_LEN],
ef[0][PART_LEN],
ef[1][PART_LEN]);
aec_rdft_inverse_128(fft);
memset(fft + PART_LEN, 0, sizeof(float) * PART_LEN);
// fft scaling
{
float scale = 2.0f / PART_LEN2;
for (j = 0; j < PART_LEN; j++) {
fft[j] *= scale;
}
}
aec_rdft_forward_128(fft);
aec->wfBuf[0][pos] += fft[0];
aec->wfBuf[0][pos + PART_LEN] += fft[1];
for (j = 1; j < PART_LEN; j++) {
aec->wfBuf[0][pos + j] += fft[2 * j];
aec->wfBuf[1][pos + j] += fft[2 * j + 1];
}
}
}
static void OverdriveAndSuppress(AecCore* aec,
float hNl[PART_LEN1],
const float hNlFb,
float efw[2][PART_LEN1]) {
int i;
for (i = 0; i < PART_LEN1; i++) {
// Weight subbands
if (hNl[i] > hNlFb) {
hNl[i] = WebRtcAec_weightCurve[i] * hNlFb +
(1 - WebRtcAec_weightCurve[i]) * hNl[i];
}
hNl[i] = powf(hNl[i], aec->overDriveSm * WebRtcAec_overDriveCurve[i]);
// Suppress error signal
efw[0][i] *= hNl[i];
efw[1][i] *= hNl[i];
// Ooura fft returns incorrect sign on imaginary component. It matters here
// because we are making an additive change with comfort noise.
efw[1][i] *= -1;
}
}
static int PartitionDelay(const AecCore* aec) {
// Measures the energy in each filter partition and returns the partition with
// highest energy.
// TODO(bjornv): Spread computational cost by computing one partition per
// block?
float wfEnMax = 0;
int i;
int delay = 0;
for (i = 0; i < aec->num_partitions; i++) {
int j;
int pos = i * PART_LEN1;
float wfEn = 0;
for (j = 0; j < PART_LEN1; j++) {
wfEn += aec->wfBuf[0][pos + j] * aec->wfBuf[0][pos + j] +
aec->wfBuf[1][pos + j] * aec->wfBuf[1][pos + j];
}
if (wfEn > wfEnMax) {
wfEnMax = wfEn;
delay = i;
}
}
return delay;
}
// Threshold to protect against the ill-effects of a zero far-end.
const float WebRtcAec_kMinFarendPSD = 15;
// Updates the following smoothed Power Spectral Densities (PSD):
// - sd : near-end
// - se : residual echo
// - sx : far-end
// - sde : cross-PSD of near-end and residual echo
// - sxd : cross-PSD of near-end and far-end
//
// In addition to updating the PSDs, also the filter diverge state is determined
// upon actions are taken.
static void SmoothedPSD(AecCore* aec,
float efw[2][PART_LEN1],
float dfw[2][PART_LEN1],
float xfw[2][PART_LEN1]) {
// Power estimate smoothing coefficients.
const float* ptrGCoh = aec->extended_filter_enabled
? WebRtcAec_kExtendedSmoothingCoefficients[aec->mult - 1]
: WebRtcAec_kNormalSmoothingCoefficients[aec->mult - 1];
int i;
float sdSum = 0, seSum = 0;
for (i = 0; i < PART_LEN1; i++) {
aec->sd[i] = ptrGCoh[0] * aec->sd[i] +
ptrGCoh[1] * (dfw[0][i] * dfw[0][i] + dfw[1][i] * dfw[1][i]);
aec->se[i] = ptrGCoh[0] * aec->se[i] +
ptrGCoh[1] * (efw[0][i] * efw[0][i] + efw[1][i] * efw[1][i]);
// We threshold here to protect against the ill-effects of a zero farend.
// The threshold is not arbitrarily chosen, but balances protection and
// adverse interaction with the algorithm's tuning.
// TODO(bjornv): investigate further why this is so sensitive.
aec->sx[i] =
ptrGCoh[0] * aec->sx[i] +
ptrGCoh[1] * WEBRTC_SPL_MAX(
xfw[0][i] * xfw[0][i] + xfw[1][i] * xfw[1][i],
WebRtcAec_kMinFarendPSD);
aec->sde[i][0] =
ptrGCoh[0] * aec->sde[i][0] +
ptrGCoh[1] * (dfw[0][i] * efw[0][i] + dfw[1][i] * efw[1][i]);
aec->sde[i][1] =
ptrGCoh[0] * aec->sde[i][1] +
ptrGCoh[1] * (dfw[0][i] * efw[1][i] - dfw[1][i] * efw[0][i]);
aec->sxd[i][0] =
ptrGCoh[0] * aec->sxd[i][0] +
ptrGCoh[1] * (dfw[0][i] * xfw[0][i] + dfw[1][i] * xfw[1][i]);
aec->sxd[i][1] =
ptrGCoh[0] * aec->sxd[i][1] +
ptrGCoh[1] * (dfw[0][i] * xfw[1][i] - dfw[1][i] * xfw[0][i]);
sdSum += aec->sd[i];
seSum += aec->se[i];
}
// Divergent filter safeguard.
aec->divergeState = (aec->divergeState ? 1.05f : 1.0f) * seSum > sdSum;
if (aec->divergeState)
memcpy(efw, dfw, sizeof(efw[0][0]) * 2 * PART_LEN1);
// Reset if error is significantly larger than nearend (13 dB).
if (!aec->extended_filter_enabled && seSum > (19.95f * sdSum))
memset(aec->wfBuf, 0, sizeof(aec->wfBuf));
}
// Window time domain data to be used by the fft.
__inline static void WindowData(float* x_windowed, const float* x) {
int i;
for (i = 0; i < PART_LEN; i++) {
x_windowed[i] = x[i] * WebRtcAec_sqrtHanning[i];
x_windowed[PART_LEN + i] =
x[PART_LEN + i] * WebRtcAec_sqrtHanning[PART_LEN - i];
}
}
// Puts fft output data into a complex valued array.
__inline static void StoreAsComplex(const float* data,
float data_complex[2][PART_LEN1]) {
int i;
data_complex[0][0] = data[0];
data_complex[1][0] = 0;
for (i = 1; i < PART_LEN; i++) {
data_complex[0][i] = data[2 * i];
data_complex[1][i] = data[2 * i + 1];
}
data_complex[0][PART_LEN] = data[1];
data_complex[1][PART_LEN] = 0;
}
static void SubbandCoherence(AecCore* aec,
float efw[2][PART_LEN1],
float xfw[2][PART_LEN1],
float* fft,
float* cohde,
float* cohxd) {
float dfw[2][PART_LEN1];
int i;
if (aec->delayEstCtr == 0)
aec->delayIdx = PartitionDelay(aec);
// Use delayed far.
memcpy(xfw,
aec->xfwBuf + aec->delayIdx * PART_LEN1,
sizeof(xfw[0][0]) * 2 * PART_LEN1);
// Windowed near fft
WindowData(fft, aec->dBuf);
aec_rdft_forward_128(fft);
StoreAsComplex(fft, dfw);
// Windowed error fft
WindowData(fft, aec->eBuf);
aec_rdft_forward_128(fft);
StoreAsComplex(fft, efw);
SmoothedPSD(aec, efw, dfw, xfw);
// Subband coherence
for (i = 0; i < PART_LEN1; i++) {
cohde[i] =
(aec->sde[i][0] * aec->sde[i][0] + aec->sde[i][1] * aec->sde[i][1]) /
(aec->sd[i] * aec->se[i] + 1e-10f);
cohxd[i] =
(aec->sxd[i][0] * aec->sxd[i][0] + aec->sxd[i][1] * aec->sxd[i][1]) /
(aec->sx[i] * aec->sd[i] + 1e-10f);
}
}
static void GetHighbandGain(const float* lambda, float* nlpGainHband) {
int i;
nlpGainHband[0] = (float)0.0;
for (i = freqAvgIc; i < PART_LEN1 - 1; i++) {
nlpGainHband[0] += lambda[i];
}
nlpGainHband[0] /= (float)(PART_LEN1 - 1 - freqAvgIc);
}
static void ComfortNoise(AecCore* aec,
float efw[2][PART_LEN1],
complex_t* comfortNoiseHband,
const float* noisePow,
const float* lambda) {
int i, num;
float rand[PART_LEN];
float noise, noiseAvg, tmp, tmpAvg;
int16_t randW16[PART_LEN];
complex_t u[PART_LEN1];
const float pi2 = 6.28318530717959f;
// Generate a uniform random array on [0 1]
WebRtcSpl_RandUArray(randW16, PART_LEN, &aec->seed);
for (i = 0; i < PART_LEN; i++) {
rand[i] = ((float)randW16[i]) / 32768;
}
// Reject LF noise
u[0][0] = 0;
u[0][1] = 0;
for (i = 1; i < PART_LEN1; i++) {
tmp = pi2 * rand[i - 1];
noise = sqrtf(noisePow[i]);
u[i][0] = noise * cosf(tmp);
u[i][1] = -noise * sinf(tmp);
}
u[PART_LEN][1] = 0;
for (i = 0; i < PART_LEN1; i++) {
// This is the proper weighting to match the background noise power
tmp = sqrtf(WEBRTC_SPL_MAX(1 - lambda[i] * lambda[i], 0));
// tmp = 1 - lambda[i];
efw[0][i] += tmp * u[i][0];
efw[1][i] += tmp * u[i][1];
}
// For H band comfort noise
// TODO: don't compute noise and "tmp" twice. Use the previous results.
noiseAvg = 0.0;
tmpAvg = 0.0;
num = 0;
if (aec->num_bands > 1 && flagHbandCn == 1) {
// average noise scale
// average over second half of freq spectrum (i.e., 4->8khz)
// TODO: we shouldn't need num. We know how many elements we're summing.
for (i = PART_LEN1 >> 1; i < PART_LEN1; i++) {
num++;
noiseAvg += sqrtf(noisePow[i]);
}
noiseAvg /= (float)num;
// average nlp scale
// average over second half of freq spectrum (i.e., 4->8khz)
// TODO: we shouldn't need num. We know how many elements we're summing.
num = 0;
for (i = PART_LEN1 >> 1; i < PART_LEN1; i++) {
num++;
tmpAvg += sqrtf(WEBRTC_SPL_MAX(1 - lambda[i] * lambda[i], 0));
}
tmpAvg /= (float)num;
// Use average noise for H band
// TODO: we should probably have a new random vector here.
// Reject LF noise
u[0][0] = 0;
u[0][1] = 0;
for (i = 1; i < PART_LEN1; i++) {
tmp = pi2 * rand[i - 1];
// Use average noise for H band
u[i][0] = noiseAvg * (float)cos(tmp);
u[i][1] = -noiseAvg * (float)sin(tmp);
}
u[PART_LEN][1] = 0;
for (i = 0; i < PART_LEN1; i++) {
// Use average NLP weight for H band
comfortNoiseHband[i][0] = tmpAvg * u[i][0];
comfortNoiseHband[i][1] = tmpAvg * u[i][1];
}
}
}
static void InitLevel(PowerLevel* level) {
const float kBigFloat = 1E17f;
level->averagelevel = 0;
level->framelevel = 0;
level->minlevel = kBigFloat;
level->frsum = 0;
level->sfrsum = 0;
level->frcounter = 0;
level->sfrcounter = 0;
}
static void InitStats(Stats* stats) {
stats->instant = kOffsetLevel;
stats->average = kOffsetLevel;
stats->max = kOffsetLevel;
stats->min = kOffsetLevel * (-1);
stats->sum = 0;
stats->hisum = 0;
stats->himean = kOffsetLevel;
stats->counter = 0;
stats->hicounter = 0;
}
static void InitMetrics(AecCore* self) {
self->stateCounter = 0;
InitLevel(&self->farlevel);
InitLevel(&self->nearlevel);
InitLevel(&self->linoutlevel);
InitLevel(&self->nlpoutlevel);
InitStats(&self->erl);
InitStats(&self->erle);
InitStats(&self->aNlp);
InitStats(&self->rerl);
}
static void UpdateLevel(PowerLevel* level, float in[2][PART_LEN1]) {
// Do the energy calculation in the frequency domain. The FFT is performed on
// a segment of PART_LEN2 samples due to overlap, but we only want the energy
// of half that data (the last PART_LEN samples). Parseval's relation states
// that the energy is preserved according to
//
// \sum_{n=0}^{N-1} |x(n)|^2 = 1/N * \sum_{n=0}^{N-1} |X(n)|^2
// = ENERGY,
//
// where N = PART_LEN2. Since we are only interested in calculating the energy
// for the last PART_LEN samples we approximate by calculating ENERGY and
// divide by 2,
//
// \sum_{n=N/2}^{N-1} |x(n)|^2 ~= ENERGY / 2
//
// Since we deal with real valued time domain signals we only store frequency
// bins [0, PART_LEN], which is what |in| consists of. To calculate ENERGY we
// need to add the contribution from the missing part in
// [PART_LEN+1, PART_LEN2-1]. These values are, up to a phase shift, identical
// with the values in [1, PART_LEN-1], hence multiply those values by 2. This
// is the values in the for loop below, but multiplication by 2 and division
// by 2 cancel.
// TODO(bjornv): Investigate reusing energy calculations performed at other
// places in the code.
int k = 1;
// Imaginary parts are zero at end points and left out of the calculation.
float energy = (in[0][0] * in[0][0]) / 2;
energy += (in[0][PART_LEN] * in[0][PART_LEN]) / 2;
for (k = 1; k < PART_LEN; k++) {
energy += (in[0][k] * in[0][k] + in[1][k] * in[1][k]);
}
energy /= PART_LEN2;
level->sfrsum += energy;
level->sfrcounter++;
if (level->sfrcounter > subCountLen) {
level->framelevel = level->sfrsum / (subCountLen * PART_LEN);
level->sfrsum = 0;
level->sfrcounter = 0;
if (level->framelevel > 0) {
if (level->framelevel < level->minlevel) {
level->minlevel = level->framelevel; // New minimum.
} else {
level->minlevel *= (1 + 0.001f); // Small increase.
}
}
level->frcounter++;
level->frsum += level->framelevel;
if (level->frcounter > countLen) {
level->averagelevel = level->frsum / countLen;
level->frsum = 0;
level->frcounter = 0;
}
}
}
static void UpdateMetrics(AecCore* aec) {
float dtmp, dtmp2;
const float actThresholdNoisy = 8.0f;
const float actThresholdClean = 40.0f;
const float safety = 0.99995f;
const float noisyPower = 300000.0f;
float actThreshold;
float echo, suppressedEcho;
if (aec->echoState) { // Check if echo is likely present
aec->stateCounter++;
}
if (aec->farlevel.frcounter == 0) {
if (aec->farlevel.minlevel < noisyPower) {
actThreshold = actThresholdClean;
} else {
actThreshold = actThresholdNoisy;
}
if ((aec->stateCounter > (0.5f * countLen * subCountLen)) &&
(aec->farlevel.sfrcounter == 0)
// Estimate in active far-end segments only
&&
(aec->farlevel.averagelevel >
(actThreshold * aec->farlevel.minlevel))) {
// Subtract noise power
echo = aec->nearlevel.averagelevel - safety * aec->nearlevel.minlevel;
// ERL
dtmp = 10 * (float)log10(aec->farlevel.averagelevel /
aec->nearlevel.averagelevel +
1e-10f);
dtmp2 = 10 * (float)log10(aec->farlevel.averagelevel / echo + 1e-10f);
aec->erl.instant = dtmp;
if (dtmp > aec->erl.max) {
aec->erl.max = dtmp;
}
if (dtmp < aec->erl.min) {
aec->erl.min = dtmp;
}
aec->erl.counter++;
aec->erl.sum += dtmp;
aec->erl.average = aec->erl.sum / aec->erl.counter;
// Upper mean
if (dtmp > aec->erl.average) {
aec->erl.hicounter++;
aec->erl.hisum += dtmp;
aec->erl.himean = aec->erl.hisum / aec->erl.hicounter;
}
// A_NLP
dtmp = 10 * (float)log10(aec->nearlevel.averagelevel /
(2 * aec->linoutlevel.averagelevel) +
1e-10f);
// subtract noise power
suppressedEcho = 2 * (aec->linoutlevel.averagelevel -
safety * aec->linoutlevel.minlevel);
dtmp2 = 10 * (float)log10(echo / suppressedEcho + 1e-10f);
aec->aNlp.instant = dtmp2;
if (dtmp > aec->aNlp.max) {
aec->aNlp.max = dtmp;
}
if (dtmp < aec->aNlp.min) {
aec->aNlp.min = dtmp;
}
aec->aNlp.counter++;
aec->aNlp.sum += dtmp;
aec->aNlp.average = aec->aNlp.sum / aec->aNlp.counter;
// Upper mean
if (dtmp > aec->aNlp.average) {
aec->aNlp.hicounter++;
aec->aNlp.hisum += dtmp;
aec->aNlp.himean = aec->aNlp.hisum / aec->aNlp.hicounter;
}
// ERLE
// subtract noise power
suppressedEcho = 2 * (aec->nlpoutlevel.averagelevel -
safety * aec->nlpoutlevel.minlevel);
dtmp = 10 * (float)log10(aec->nearlevel.averagelevel /
(2 * aec->nlpoutlevel.averagelevel) +
1e-10f);
dtmp2 = 10 * (float)log10(echo / suppressedEcho + 1e-10f);
dtmp = dtmp2;
aec->erle.instant = dtmp;
if (dtmp > aec->erle.max) {
aec->erle.max = dtmp;
}
if (dtmp < aec->erle.min) {
aec->erle.min = dtmp;
}
aec->erle.counter++;
aec->erle.sum += dtmp;
aec->erle.average = aec->erle.sum / aec->erle.counter;
// Upper mean
if (dtmp > aec->erle.average) {
aec->erle.hicounter++;
aec->erle.hisum += dtmp;
aec->erle.himean = aec->erle.hisum / aec->erle.hicounter;
}
}
aec->stateCounter = 0;
}
}
static void UpdateDelayMetrics(AecCore* self) {
int i = 0;
int delay_values = 0;
int median = 0;
int lookahead = WebRtc_lookahead(self->delay_estimator);
const int kMsPerBlock = PART_LEN / (self->mult * 8);
int64_t l1_norm = 0;
if (self->num_delay_values == 0) {
// We have no new delay value data. Even though -1 is a valid |median| in
// the sense that we allow negative values, it will practically never be
// used since multiples of |kMsPerBlock| will always be returned.
// We therefore use -1 to indicate in the logs that the delay estimator was
// not able to estimate the delay.
self->delay_median = -1;
self->delay_std = -1;
self->fraction_poor_delays = -1;
return;
}
// Start value for median count down.
delay_values = self->num_delay_values >> 1;
// Get median of delay values since last update.
for (i = 0; i < kHistorySizeBlocks; i++) {
delay_values -= self->delay_histogram[i];
if (delay_values < 0) {
median = i;
break;
}
}
// Account for lookahead.
self->delay_median = (median - lookahead) * kMsPerBlock;
// Calculate the L1 norm, with median value as central moment.
for (i = 0; i < kHistorySizeBlocks; i++) {
l1_norm += abs(i - median) * self->delay_histogram[i];
}
self->delay_std = (int)((l1_norm + self->num_delay_values / 2) /
self->num_delay_values) * kMsPerBlock;
// Determine fraction of delays that are out of bounds, that is, either
// negative (anti-causal system) or larger than the AEC filter length.
{
int num_delays_out_of_bounds = self->num_delay_values;
const int histogram_length = sizeof(self->delay_histogram) /
sizeof(self->delay_histogram[0]);
for (i = lookahead; i < lookahead + self->num_partitions; ++i) {
if (i < histogram_length)
num_delays_out_of_bounds -= self->delay_histogram[i];
}
self->fraction_poor_delays = (float)num_delays_out_of_bounds /
self->num_delay_values;
}
// Reset histogram.
memset(self->delay_histogram, 0, sizeof(self->delay_histogram));
self->num_delay_values = 0;
return;
}
static void TimeToFrequency(float time_data[PART_LEN2],
float freq_data[2][PART_LEN1],
int window) {
int i = 0;
// TODO(bjornv): Should we have a different function/wrapper for windowed FFT?
if (window) {
for (i = 0; i < PART_LEN; i++) {
time_data[i] *= WebRtcAec_sqrtHanning[i];
time_data[PART_LEN + i] *= WebRtcAec_sqrtHanning[PART_LEN - i];
}
}
aec_rdft_forward_128(time_data);
// Reorder.
freq_data[1][0] = 0;
freq_data[1][PART_LEN] = 0;
freq_data[0][0] = time_data[0];
freq_data[0][PART_LEN] = time_data[1];
for (i = 1; i < PART_LEN; i++) {
freq_data[0][i] = time_data[2 * i];
freq_data[1][i] = time_data[2 * i + 1];
}
}
static int MoveFarReadPtrWithoutSystemDelayUpdate(AecCore* self, int elements) {
WebRtc_MoveReadPtr(self->far_buf_windowed, elements);
#ifdef WEBRTC_AEC_DEBUG_DUMP
WebRtc_MoveReadPtr(self->far_time_buf, elements);
#endif
return WebRtc_MoveReadPtr(self->far_buf, elements);
}
static int SignalBasedDelayCorrection(AecCore* self) {
int delay_correction = 0;
int last_delay = -2;
assert(self != NULL);
#if !defined(WEBRTC_ANDROID) && !defined(WEBRTC_GONK)
// On desktops, turn on correction after |kDelayCorrectionStart| frames. This
// is to let the delay estimation get a chance to converge. Also, if the
// playout audio volume is low (or even muted) the delay estimation can return
// a very large delay, which will break the AEC if it is applied.
if (self->frame_count < kDelayCorrectionStart) {
return 0;
}
#endif
// 1. Check for non-negative delay estimate. Note that the estimates we get
// from the delay estimation are not compensated for lookahead. Hence, a
// negative |last_delay| is an invalid one.
// 2. Verify that there is a delay change. In addition, only allow a change
// if the delay is outside a certain region taking the AEC filter length
// into account.
// TODO(bjornv): Investigate if we can remove the non-zero delay change check.
// 3. Only allow delay correction if the delay estimation quality exceeds
// |delay_quality_threshold|.
// 4. Finally, verify that the proposed |delay_correction| is feasible by
// comparing with the size of the far-end buffer.
last_delay = WebRtc_last_delay(self->delay_estimator);
if ((last_delay >= 0) &&
(last_delay != self->previous_delay) &&
(WebRtc_last_delay_quality(self->delay_estimator) >
self->delay_quality_threshold)) {
int delay = last_delay - WebRtc_lookahead(self->delay_estimator);
// Allow for a slack in the actual delay, defined by a |lower_bound| and an
// |upper_bound|. The adaptive echo cancellation filter is currently
// |num_partitions| (of 64 samples) long. If the delay estimate is negative
// or at least 3/4 of the filter length we open up for correction.
const int lower_bound = 0;
const int upper_bound = self->num_partitions * 3 / 4;
const int do_correction = delay <= lower_bound || delay > upper_bound;
if (do_correction == 1) {
int available_read = (int)WebRtc_available_read(self->far_buf);
// With |shift_offset| we gradually rely on the delay estimates. For
// positive delays we reduce the correction by |shift_offset| to lower the
// risk of pushing the AEC into a non causal state. For negative delays
// we rely on the values up to a rounding error, hence compensate by 1
// element to make sure to push the delay into the causal region.
delay_correction = -delay;
delay_correction += delay > self->shift_offset ? self->shift_offset : 1;
self->shift_offset--;
self->shift_offset = (self->shift_offset <= 1 ? 1 : self->shift_offset);
if (delay_correction > available_read - self->mult - 1) {
// There is not enough data in the buffer to perform this shift. Hence,
// we do not rely on the delay estimate and do nothing.
delay_correction = 0;
} else {
self->previous_delay = last_delay;
++self->delay_correction_count;
}
}
}
// Update the |delay_quality_threshold| once we have our first delay
// correction.
if (self->delay_correction_count > 0) {
float delay_quality = WebRtc_last_delay_quality(self->delay_estimator);
delay_quality = (delay_quality > kDelayQualityThresholdMax ?
kDelayQualityThresholdMax : delay_quality);
self->delay_quality_threshold =
(delay_quality > self->delay_quality_threshold ? delay_quality :
self->delay_quality_threshold);
}
return delay_correction;
}
#ifdef WEBRTC_AEC_DEBUG_DUMP
// Open a new Wav file for writing. If it was already open with a different
// sample frequency, close it first.
static void ReopenWav(rtc_WavWriter** wav_file,
const char* name,
int seq1,
int seq2,
int sample_rate) {
int written /*UNUSED*/;
char path[1024];
char *filename;
if (*wav_file) {
if (rtc_WavSampleRate(*wav_file) == sample_rate)
return;
rtc_WavClose(*wav_file);
*wav_file = NULL;
}
AECDebugFilenameBase(path, sizeof(path));
filename = path + strlen(path);
if (filename > path) {
#ifdef WEBRTC_WIN
if (*(filename-1) != '\\') {
*filename++ = '\\';
}
#else
if (*(filename-1) != '/') {
*filename++ = '/';
}
#endif
}
written = snprintf(filename, sizeof(path) - (filename-path), "%s%d-%d.wav",
name, seq1, seq2);
assert(written >= 0); // no output error
assert(filename+written < path + sizeof(path)-1); // buffer was large enough
*wav_file = rtc_WavOpen(path, sample_rate, 1);
}
static void
OpenCoreDebugFiles(AecCore* aec, int *aec_instance_count)
{
if (AECDebug())
{
if (!aec->farFile)
{
int process_rate = aec->sampFreq > 16000 ? 16000 : aec->sampFreq;
ReopenWav(&aec->farFile, "aec_far",
aec->instance_index, aec->debug_dump_count, process_rate);
ReopenWav(&aec->nearFile, "aec_near",
aec->instance_index, aec->debug_dump_count, process_rate);
ReopenWav(&aec->outFile, "aec_out",
aec->instance_index, aec->debug_dump_count, process_rate);
ReopenWav(&aec->outLinearFile, "aec_out_linear",
aec->instance_index, aec->debug_dump_count, process_rate);
ReopenWav(&aec->e_fft_file, "aec_fft",
aec->instance_index, aec->debug_dump_count, process_rate);
++aec->debug_dump_count;
}
} else {
if (aec->farFile) {
rtc_WavClose(aec->farFile);
}
if (aec->nearFile) {
rtc_WavClose(aec->nearFile);
}
if (aec->outFile) {
rtc_WavClose(aec->outFile);
}
if (aec->outLinearFile) {
rtc_WavClose(aec->outLinearFile);
}
if (aec->e_fft_file) {
rtc_WavClose(aec->e_fft_file);
}
aec->outLinearFile = aec->outFile = aec->nearFile = aec->farFile = aec->e_fft_file = NULL;
aec->debugWritten = 0;
}
}
#endif
static void NonLinearProcessing(AecCore* aec,
float* output,
float* const* outputH) {
float efw[2][PART_LEN1], xfw[2][PART_LEN1];
complex_t comfortNoiseHband[PART_LEN1];
float fft[PART_LEN2];
float scale, dtmp;
float nlpGainHband;
int i;
size_t j;
// Coherence and non-linear filter
float cohde[PART_LEN1], cohxd[PART_LEN1];
float hNlDeAvg, hNlXdAvg;
float hNl[PART_LEN1];
float hNlPref[kPrefBandSize];
float hNlFb = 0, hNlFbLow = 0;
const float prefBandQuant = 0.75f, prefBandQuantLow = 0.5f;
const int prefBandSize = kPrefBandSize / aec->mult;
const int minPrefBand = 4 / aec->mult;
// Power estimate smoothing coefficients.
const float* min_overdrive = aec->extended_filter_enabled
? kExtendedMinOverDrive
: kNormalMinOverDrive;
// Filter energy
const int delayEstInterval = 10 * aec->mult;
float* xfw_ptr = NULL;
aec->delayEstCtr++;
if (aec->delayEstCtr == delayEstInterval) {
aec->delayEstCtr = 0;
}
// initialize comfort noise for H band
memset(comfortNoiseHband, 0, sizeof(comfortNoiseHband));
nlpGainHband = (float)0.0;
dtmp = (float)0.0;
// We should always have at least one element stored in |far_buf|.
assert(WebRtc_available_read(aec->far_buf_windowed) > 0);
// NLP
WebRtc_ReadBuffer(aec->far_buf_windowed, (void**)&xfw_ptr, &xfw[0][0], 1);
// TODO(bjornv): Investigate if we can reuse |far_buf_windowed| instead of
// |xfwBuf|.
// Buffer far.
memcpy(aec->xfwBuf, xfw_ptr, sizeof(float) * 2 * PART_LEN1);
WebRtcAec_SubbandCoherence(aec, efw, xfw, fft, cohde, cohxd);
hNlXdAvg = 0;
for (i = minPrefBand; i < prefBandSize + minPrefBand; i++) {
hNlXdAvg += cohxd[i];
}
hNlXdAvg /= prefBandSize;
hNlXdAvg = 1 - hNlXdAvg;
hNlDeAvg = 0;
for (i = minPrefBand; i < prefBandSize + minPrefBand; i++) {
hNlDeAvg += cohde[i];
}
hNlDeAvg /= prefBandSize;
if (hNlXdAvg < 0.75f && hNlXdAvg < aec->hNlXdAvgMin) {
aec->hNlXdAvgMin = hNlXdAvg;
}
if (hNlDeAvg > 0.98f && hNlXdAvg > 0.9f) {
aec->stNearState = 1;
} else if (hNlDeAvg < 0.95f || hNlXdAvg < 0.8f) {
aec->stNearState = 0;
}
if (aec->hNlXdAvgMin == 1) {
aec->echoState = 0;
aec->overDrive = min_overdrive[aec->nlp_mode];
if (aec->stNearState == 1) {
memcpy(hNl, cohde, sizeof(hNl));
hNlFb = hNlDeAvg;
hNlFbLow = hNlDeAvg;
} else {
for (i = 0; i < PART_LEN1; i++) {
hNl[i] = 1 - cohxd[i];
}
hNlFb = hNlXdAvg;
hNlFbLow = hNlXdAvg;
}
} else {
if (aec->stNearState == 1) {
aec->echoState = 0;
memcpy(hNl, cohde, sizeof(hNl));
hNlFb = hNlDeAvg;
hNlFbLow = hNlDeAvg;
} else {
aec->echoState = 1;
for (i = 0; i < PART_LEN1; i++) {
hNl[i] = WEBRTC_SPL_MIN(cohde[i], 1 - cohxd[i]);
}
// Select an order statistic from the preferred bands.
// TODO: Using quicksort now, but a selection algorithm may be preferred.
memcpy(hNlPref, &hNl[minPrefBand], sizeof(float) * prefBandSize);
qsort(hNlPref, prefBandSize, sizeof(float), CmpFloat);
hNlFb = hNlPref[(int)floor(prefBandQuant * (prefBandSize - 1))];
hNlFbLow = hNlPref[(int)floor(prefBandQuantLow * (prefBandSize - 1))];
}
}
// Track the local filter minimum to determine suppression overdrive.
if (hNlFbLow < 0.6f && hNlFbLow < aec->hNlFbLocalMin) {
aec->hNlFbLocalMin = hNlFbLow;
aec->hNlFbMin = hNlFbLow;
aec->hNlNewMin = 1;
aec->hNlMinCtr = 0;
}
aec->hNlFbLocalMin =
WEBRTC_SPL_MIN(aec->hNlFbLocalMin + 0.0008f / aec->mult, 1);
aec->hNlXdAvgMin = WEBRTC_SPL_MIN(aec->hNlXdAvgMin + 0.0006f / aec->mult, 1);
if (aec->hNlNewMin == 1) {
aec->hNlMinCtr++;
}
if (aec->hNlMinCtr == 2) {
aec->hNlNewMin = 0;
aec->hNlMinCtr = 0;
aec->overDrive =
WEBRTC_SPL_MAX(kTargetSupp[aec->nlp_mode] /
((float)log(aec->hNlFbMin + 1e-10f) + 1e-10f),
min_overdrive[aec->nlp_mode]);
}
// Smooth the overdrive.
if (aec->overDrive < aec->overDriveSm) {
aec->overDriveSm = 0.99f * aec->overDriveSm + 0.01f * aec->overDrive;
} else {
aec->overDriveSm = 0.9f * aec->overDriveSm + 0.1f * aec->overDrive;
}
WebRtcAec_OverdriveAndSuppress(aec, hNl, hNlFb, efw);
// Add comfort noise.
WebRtcAec_ComfortNoise(aec, efw, comfortNoiseHband, aec->noisePow, hNl);
// TODO(bjornv): Investigate how to take the windowing below into account if
// needed.
if (aec->metricsMode == 1) {
// Note that we have a scaling by two in the time domain |eBuf|.
// In addition the time domain signal is windowed before transformation,
// losing half the energy on the average. We take care of the first
// scaling only in UpdateMetrics().
UpdateLevel(&aec->nlpoutlevel, efw);
}
// Inverse error fft.
fft[0] = efw[0][0];
fft[1] = efw[0][PART_LEN];
for (i = 1; i < PART_LEN; i++) {
fft[2 * i] = efw[0][i];
// Sign change required by Ooura fft.
fft[2 * i + 1] = -efw[1][i];
}
aec_rdft_inverse_128(fft);
// Overlap and add to obtain output.
scale = 2.0f / PART_LEN2;
for (i = 0; i < PART_LEN; i++) {
fft[i] *= scale; // fft scaling
fft[i] = fft[i] * WebRtcAec_sqrtHanning[i] + aec->outBuf[i];
fft[PART_LEN + i] *= scale; // fft scaling
aec->outBuf[i] = fft[PART_LEN + i] * WebRtcAec_sqrtHanning[PART_LEN - i];
// Saturate output to keep it in the allowed range.
output[i] = WEBRTC_SPL_SAT(
WEBRTC_SPL_WORD16_MAX, fft[i], WEBRTC_SPL_WORD16_MIN);
}
// For H band
if (aec->num_bands > 1) {
// H band gain
// average nlp over low band: average over second half of freq spectrum
// (4->8khz)
GetHighbandGain(hNl, &nlpGainHband);
// Inverse comfort_noise
if (flagHbandCn == 1) {
fft[0] = comfortNoiseHband[0][0];
fft[1] = comfortNoiseHband[PART_LEN][0];
for (i = 1; i < PART_LEN; i++) {
fft[2 * i] = comfortNoiseHband[i][0];
fft[2 * i + 1] = comfortNoiseHband[i][1];
}
aec_rdft_inverse_128(fft);
scale = 2.0f / PART_LEN2;
}
// compute gain factor
for (j = 0; j < aec->num_bands - 1; ++j) {
for (i = 0; i < PART_LEN; i++) {
dtmp = aec->dBufH[j][i];
dtmp = dtmp * nlpGainHband; // for variable gain
// add some comfort noise where Hband is attenuated
if (flagHbandCn == 1 && j == 0) {
fft[i] *= scale; // fft scaling
dtmp += cnScaleHband * fft[i];
}
// Saturate output to keep it in the allowed range.
outputH[j][i] = WEBRTC_SPL_SAT(
WEBRTC_SPL_WORD16_MAX, dtmp, WEBRTC_SPL_WORD16_MIN);
}
}
}
// Copy the current block to the old position.
memcpy(aec->dBuf, aec->dBuf + PART_LEN, sizeof(float) * PART_LEN);
memcpy(aec->eBuf, aec->eBuf + PART_LEN, sizeof(float) * PART_LEN);
// Copy the current block to the old position for H band
for (j = 0; j < aec->num_bands - 1; ++j) {
memcpy(aec->dBufH[j], aec->dBufH[j] + PART_LEN, sizeof(float) * PART_LEN);
}
memmove(aec->xfwBuf + PART_LEN1,
aec->xfwBuf,
sizeof(aec->xfwBuf) - sizeof(complex_t) * PART_LEN1);
}
static void ProcessBlock(AecCore* aec) {
size_t i;
float y[PART_LEN], e[PART_LEN];
float scale;
float fft[PART_LEN2];
float xf[2][PART_LEN1], yf[2][PART_LEN1], ef[2][PART_LEN1];
float df[2][PART_LEN1];
float far_spectrum = 0.0f;
float near_spectrum = 0.0f;
float abs_far_spectrum[PART_LEN1];
float abs_near_spectrum[PART_LEN1];
const float gPow[2] = {0.9f, 0.1f};
// Noise estimate constants.
const int noiseInitBlocks = 500 * aec->mult;
const float step = 0.1f;
const float ramp = 1.0002f;
const float gInitNoise[2] = {0.999f, 0.001f};
float nearend[PART_LEN];
float* nearend_ptr = NULL;
float output[PART_LEN];
float outputH[NUM_HIGH_BANDS_MAX][PART_LEN];
float* outputH_ptr[NUM_HIGH_BANDS_MAX];
for (i = 0; i < NUM_HIGH_BANDS_MAX; ++i) {
outputH_ptr[i] = outputH[i];
}
float* xf_ptr = NULL;
// Concatenate old and new nearend blocks.
for (i = 0; i < aec->num_bands - 1; ++i) {
WebRtc_ReadBuffer(aec->nearFrBufH[i],
(void**)&nearend_ptr,
nearend,
PART_LEN);
memcpy(aec->dBufH[i] + PART_LEN, nearend_ptr, sizeof(nearend));
}
WebRtc_ReadBuffer(aec->nearFrBuf, (void**)&nearend_ptr, nearend, PART_LEN);
memcpy(aec->dBuf + PART_LEN, nearend_ptr, sizeof(nearend));
// ---------- Ooura fft ----------
#ifdef WEBRTC_AEC_DEBUG_DUMP
{
float farend[PART_LEN];
float* farend_ptr = NULL;
WebRtc_ReadBuffer(aec->far_time_buf, (void**)&farend_ptr, farend, 1);
OpenCoreDebugFiles(aec, &webrtc_aec_instance_count);
if (aec->farFile) {
rtc_WavWriteSamples(aec->farFile, farend_ptr, PART_LEN);
rtc_WavWriteSamples(aec->nearFile, nearend_ptr, PART_LEN);
aec->debugWritten += sizeof(int16_t) * PART_LEN;
if (aec->debugWritten >= AECDebugMaxSize()) {
AECDebugEnable(0);
}
}
}
#endif
// We should always have at least one element stored in |far_buf|.
assert(WebRtc_available_read(aec->far_buf) > 0);
WebRtc_ReadBuffer(aec->far_buf, (void**)&xf_ptr, &xf[0][0], 1);
// Near fft
memcpy(fft, aec->dBuf, sizeof(float) * PART_LEN2);
TimeToFrequency(fft, df, 0);
// Power smoothing
for (i = 0; i < PART_LEN1; i++) {
far_spectrum = (xf_ptr[i] * xf_ptr[i]) +
(xf_ptr[PART_LEN1 + i] * xf_ptr[PART_LEN1 + i]);
aec->xPow[i] =
gPow[0] * aec->xPow[i] + gPow[1] * aec->num_partitions * far_spectrum;
// Calculate absolute spectra
abs_far_spectrum[i] = sqrtf(far_spectrum);
near_spectrum = df[0][i] * df[0][i] + df[1][i] * df[1][i];
aec->dPow[i] = gPow[0] * aec->dPow[i] + gPow[1] * near_spectrum;
// Calculate absolute spectra
abs_near_spectrum[i] = sqrtf(near_spectrum);
}
// Estimate noise power. Wait until dPow is more stable.
if (aec->noiseEstCtr > 50) {
for (i = 0; i < PART_LEN1; i++) {
if (aec->dPow[i] < aec->dMinPow[i]) {
aec->dMinPow[i] =
(aec->dPow[i] + step * (aec->dMinPow[i] - aec->dPow[i])) * ramp;
} else {
aec->dMinPow[i] *= ramp;
}
}
}
// Smooth increasing noise power from zero at the start,
// to avoid a sudden burst of comfort noise.
if (aec->noiseEstCtr < noiseInitBlocks) {
aec->noiseEstCtr++;
for (i = 0; i < PART_LEN1; i++) {
if (aec->dMinPow[i] > aec->dInitMinPow[i]) {
aec->dInitMinPow[i] = gInitNoise[0] * aec->dInitMinPow[i] +
gInitNoise[1] * aec->dMinPow[i];
} else {
aec->dInitMinPow[i] = aec->dMinPow[i];
}
}
aec->noisePow = aec->dInitMinPow;
} else {
aec->noisePow = aec->dMinPow;
}
// Block wise delay estimation used for logging
if (aec->delay_logging_enabled) {
if (WebRtc_AddFarSpectrumFloat(
aec->delay_estimator_farend, abs_far_spectrum, PART_LEN1) == 0) {
int delay_estimate = WebRtc_DelayEstimatorProcessFloat(
aec->delay_estimator, abs_near_spectrum, PART_LEN1);
if (delay_estimate >= 0) {
// Update delay estimate buffer.
aec->delay_histogram[delay_estimate]++;
aec->num_delay_values++;
}
if (aec->delay_metrics_delivered == 1 &&
aec->num_delay_values >= kDelayMetricsAggregationWindow) {
UpdateDelayMetrics(aec);
}
}
}
// Update the xfBuf block position.
aec->xfBufBlockPos--;
if (aec->xfBufBlockPos == -1) {
aec->xfBufBlockPos = aec->num_partitions - 1;
}
// Buffer xf
memcpy(aec->xfBuf[0] + aec->xfBufBlockPos * PART_LEN1,
xf_ptr,
sizeof(float) * PART_LEN1);
memcpy(aec->xfBuf[1] + aec->xfBufBlockPos * PART_LEN1,
&xf_ptr[PART_LEN1],
sizeof(float) * PART_LEN1);
memset(yf, 0, sizeof(yf));
// Filter far
WebRtcAec_FilterFar(aec, yf);
// Inverse fft to obtain echo estimate and error.
fft[0] = yf[0][0];
fft[1] = yf[0][PART_LEN];
for (i = 1; i < PART_LEN; i++) {
fft[2 * i] = yf[0][i];
fft[2 * i + 1] = yf[1][i];
}
aec_rdft_inverse_128(fft);
scale = 2.0f / PART_LEN2;
for (i = 0; i < PART_LEN; i++) {
y[i] = fft[PART_LEN + i] * scale; // fft scaling
}
for (i = 0; i < PART_LEN; i++) {
e[i] = nearend_ptr[i] - y[i];
}
// Error fft
memcpy(aec->eBuf + PART_LEN, e, sizeof(float) * PART_LEN);
memset(fft, 0, sizeof(float) * PART_LEN);
memcpy(fft + PART_LEN, e, sizeof(float) * PART_LEN);
// TODO(bjornv): Change to use TimeToFrequency().
aec_rdft_forward_128(fft);
ef[1][0] = 0;
ef[1][PART_LEN] = 0;
ef[0][0] = fft[0];
ef[0][PART_LEN] = fft[1];
for (i = 1; i < PART_LEN; i++) {
ef[0][i] = fft[2 * i];
ef[1][i] = fft[2 * i + 1];
}
#ifdef WEBRTC_AEC_DEBUG_DUMP
if (aec->e_fft_file) {
rtc_WavWriteSamples(aec->e_fft_file, &ef[0][0],
sizeof(ef[0][0]) * PART_LEN1 * 2);
}
#endif
if (aec->metricsMode == 1) {
// Note that the first PART_LEN samples in fft (before transformation) are
// zero. Hence, the scaling by two in UpdateLevel() should not be
// performed. That scaling is taken care of in UpdateMetrics() instead.
UpdateLevel(&aec->linoutlevel, ef);
}
// Scale error signal inversely with far power.
WebRtcAec_ScaleErrorSignal(aec, ef);
WebRtcAec_FilterAdaptation(aec, fft, ef);
NonLinearProcessing(aec, output, outputH_ptr);
if (aec->metricsMode == 1) {
// Update power levels and echo metrics
UpdateLevel(&aec->farlevel, (float(*)[PART_LEN1])xf_ptr);
UpdateLevel(&aec->nearlevel, df);
UpdateMetrics(aec);
}
// Store the output block.
WebRtc_WriteBuffer(aec->outFrBuf, output, PART_LEN);
// For high bands
for (i = 0; i < aec->num_bands - 1; ++i) {
WebRtc_WriteBuffer(aec->outFrBufH[i], outputH[i], PART_LEN);
}
#ifdef WEBRTC_AEC_DEBUG_DUMP
OpenCoreDebugFiles(aec, &webrtc_aec_instance_count);
if (aec->outLinearFile) {
rtc_WavWriteSamples(aec->outLinearFile, e, PART_LEN);
rtc_WavWriteSamples(aec->outFile, output, PART_LEN);
}
#endif
}
AecCore* WebRtcAec_CreateAec() {
int i;
AecCore* aec = malloc(sizeof(AecCore));
if (!aec) {
return NULL;
}
// set the mem with 0 in order to prevent garbage data
memset(aec, 0, sizeof(*aec));
aec->nearFrBuf = WebRtc_CreateBuffer(FRAME_LEN + PART_LEN, sizeof(float));
if (!aec->nearFrBuf) {
WebRtcAec_FreeAec(aec);
return NULL;
}
aec->outFrBuf = WebRtc_CreateBuffer(FRAME_LEN + PART_LEN, sizeof(float));
if (!aec->outFrBuf) {
WebRtcAec_FreeAec(aec);
return NULL;
}
for (i = 0; i < NUM_HIGH_BANDS_MAX; ++i) {
aec->nearFrBufH[i] = WebRtc_CreateBuffer(FRAME_LEN + PART_LEN,
sizeof(float));
if (!aec->nearFrBufH[i]) {
WebRtcAec_FreeAec(aec);
return NULL;
}
aec->outFrBufH[i] = WebRtc_CreateBuffer(FRAME_LEN + PART_LEN,
sizeof(float));
if (!aec->outFrBufH[i]) {
WebRtcAec_FreeAec(aec);
return NULL;
}
}
// Create far-end buffers.
aec->far_buf =
WebRtc_CreateBuffer(kBufSizePartitions, sizeof(float) * 2 * PART_LEN1);
if (!aec->far_buf) {
WebRtcAec_FreeAec(aec);
return NULL;
}
aec->far_buf_windowed =
WebRtc_CreateBuffer(kBufSizePartitions, sizeof(float) * 2 * PART_LEN1);
if (!aec->far_buf_windowed) {
WebRtcAec_FreeAec(aec);
return NULL;
}
#ifdef WEBRTC_AEC_DEBUG_DUMP
aec->instance_index = webrtc_aec_instance_count;
aec->far_time_buf =
WebRtc_CreateBuffer(kBufSizePartitions, sizeof(float) * PART_LEN);
if (!aec->far_time_buf) {
WebRtcAec_FreeAec(aec);
return NULL;
}
aec->farFile = aec->nearFile = aec->outFile = aec->outLinearFile = aec->e_fft_file = NULL;
aec->debug_dump_count = 0;
aec->debugWritten = 0;
OpenCoreDebugFiles(aec, &webrtc_aec_instance_count);
#endif
aec->delay_estimator_farend =
WebRtc_CreateDelayEstimatorFarend(PART_LEN1, kHistorySizeBlocks);
if (aec->delay_estimator_farend == NULL) {
WebRtcAec_FreeAec(aec);
return NULL;
}
// We create the delay_estimator with the same amount of maximum lookahead as
// the delay history size (kHistorySizeBlocks) for symmetry reasons.
aec->delay_estimator = WebRtc_CreateDelayEstimator(
aec->delay_estimator_farend, kHistorySizeBlocks);
if (aec->delay_estimator == NULL) {
WebRtcAec_FreeAec(aec);
return NULL;
}
#if defined(WEBRTC_ANDROID) || defined(WEBRTC_GONK)
aec->delay_agnostic_enabled = 1; // DA-AEC enabled by default.
// DA-AEC assumes the system is causal from the beginning and will self adjust
// the lookahead when shifting is required.
WebRtc_set_lookahead(aec->delay_estimator, 0);
#else
aec->delay_agnostic_enabled = 0;
WebRtc_set_lookahead(aec->delay_estimator, kLookaheadBlocks);
#endif
aec->extended_filter_enabled = 0;
static bool initted = false;
if (!initted) {
initted = true;
// Assembly optimization
WebRtcAec_FilterFar = FilterFar;
WebRtcAec_ScaleErrorSignal = ScaleErrorSignal;
WebRtcAec_FilterAdaptation = FilterAdaptation;
WebRtcAec_OverdriveAndSuppress = OverdriveAndSuppress;
WebRtcAec_ComfortNoise = ComfortNoise;
WebRtcAec_SubbandCoherence = SubbandCoherence;
#if defined(WEBRTC_ARCH_X86_FAMILY)
if (WebRtc_GetCPUInfo(kSSE2)) {
WebRtcAec_InitAec_SSE2();
}
#endif
#if defined(MIPS_FPU_LE)
WebRtcAec_InitAec_mips();
#endif
#if defined(WEBRTC_ARCH_ARM_NEON)
WebRtcAec_InitAec_neon();
#elif defined(WEBRTC_DETECT_ARM_NEON)
if ((WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) != 0) {
WebRtcAec_InitAec_neon();
}
#endif
aec_rdft_init();
}
return aec;
}
void WebRtcAec_FreeAec(AecCore* aec) {
int i;
if (aec == NULL) {
return;
}
WebRtc_FreeBuffer(aec->nearFrBuf);
WebRtc_FreeBuffer(aec->outFrBuf);
for (i = 0; i < NUM_HIGH_BANDS_MAX; ++i) {
WebRtc_FreeBuffer(aec->nearFrBufH[i]);
WebRtc_FreeBuffer(aec->outFrBufH[i]);
}
WebRtc_FreeBuffer(aec->far_buf);
WebRtc_FreeBuffer(aec->far_buf_windowed);
#ifdef WEBRTC_AEC_DEBUG_DUMP
WebRtc_FreeBuffer(aec->far_time_buf);
if (aec->farFile) {
// we don't let one be open and not the others
rtc_WavClose(aec->farFile);
rtc_WavClose(aec->nearFile);
rtc_WavClose(aec->outFile);
rtc_WavClose(aec->outLinearFile);
rtc_WavClose(aec->e_fft_file);
}
#endif
WebRtc_FreeDelayEstimator(aec->delay_estimator);
WebRtc_FreeDelayEstimatorFarend(aec->delay_estimator_farend);
free(aec);
}
int WebRtcAec_InitAec(AecCore* aec, int sampFreq) {
int i;
aec->sampFreq = sampFreq;
if (sampFreq == 8000) {
aec->normal_mu = 0.6f;
aec->normal_error_threshold = 2e-6f;
aec->num_bands = 1;
} else {
aec->normal_mu = 0.5f;
aec->normal_error_threshold = 1.5e-6f;
aec->num_bands = (size_t)(sampFreq / 16000);
}
WebRtc_InitBuffer(aec->nearFrBuf);
WebRtc_InitBuffer(aec->outFrBuf);
for (i = 0; i < NUM_HIGH_BANDS_MAX; ++i) {
WebRtc_InitBuffer(aec->nearFrBufH[i]);
WebRtc_InitBuffer(aec->outFrBufH[i]);
}
// Initialize far-end buffers.
WebRtc_InitBuffer(aec->far_buf);
WebRtc_InitBuffer(aec->far_buf_windowed);
#ifdef WEBRTC_AEC_DEBUG_DUMP
WebRtc_InitBuffer(aec->far_time_buf);
aec->instance_index = webrtc_aec_instance_count;
OpenCoreDebugFiles(aec, &webrtc_aec_instance_count);
#endif
aec->system_delay = 0;
if (WebRtc_InitDelayEstimatorFarend(aec->delay_estimator_farend) != 0) {
return -1;
}
if (WebRtc_InitDelayEstimator(aec->delay_estimator) != 0) {
return -1;
}
aec->delay_logging_enabled = 0;
aec->delay_metrics_delivered = 0;
memset(aec->delay_histogram, 0, sizeof(aec->delay_histogram));
aec->num_delay_values = 0;
aec->delay_median = -1;
aec->delay_std = -1;
aec->fraction_poor_delays = -1.0f;
aec->signal_delay_correction = 0;
aec->previous_delay = -2; // (-2): Uninitialized.
aec->delay_correction_count = 0;
aec->shift_offset = kInitialShiftOffset;
aec->delay_quality_threshold = kDelayQualityThresholdMin;
aec->num_partitions = kNormalNumPartitions;
// Update the delay estimator with filter length. We use half the
// |num_partitions| to take the echo path into account. In practice we say
// that the echo has a duration of maximum half |num_partitions|, which is not
// true, but serves as a crude measure.
WebRtc_set_allowed_offset(aec->delay_estimator, aec->num_partitions / 2);
// TODO(bjornv): I currently hard coded the enable. Once we've established
// that AECM has no performance regression, robust_validation will be enabled
// all the time and the APIs to turn it on/off will be removed. Hence, remove
// this line then.
WebRtc_enable_robust_validation(aec->delay_estimator, 1);
aec->frame_count = 0;
// Default target suppression mode.
aec->nlp_mode = 1;
// Sampling frequency multiplier w.r.t. 8 kHz.
// In case of multiple bands we process the lower band in 16 kHz, hence the
// multiplier is always 2.
if (aec->num_bands > 1) {
aec->mult = 2;
} else {
aec->mult = (short)aec->sampFreq / 8000;
}
aec->farBufWritePos = 0;
aec->farBufReadPos = 0;
aec->inSamples = 0;
aec->outSamples = 0;
aec->knownDelay = 0;
// Initialize buffers
memset(aec->dBuf, 0, sizeof(aec->dBuf));
memset(aec->eBuf, 0, sizeof(aec->eBuf));
// For H bands
for (i = 0; i < NUM_HIGH_BANDS_MAX; ++i) {
memset(aec->dBufH[i], 0, sizeof(aec->dBufH[i]));
}
memset(aec->xPow, 0, sizeof(aec->xPow));
memset(aec->dPow, 0, sizeof(aec->dPow));
memset(aec->dInitMinPow, 0, sizeof(aec->dInitMinPow));
aec->noisePow = aec->dInitMinPow;
aec->noiseEstCtr = 0;
// Initial comfort noise power
for (i = 0; i < PART_LEN1; i++) {
aec->dMinPow[i] = 1.0e6f;
}
// Holds the last block written to
aec->xfBufBlockPos = 0;
// TODO: Investigate need for these initializations. Deleting them doesn't
// change the output at all and yields 0.4% overall speedup.
memset(aec->xfBuf, 0, sizeof(complex_t) * kExtendedNumPartitions * PART_LEN1);
memset(aec->wfBuf, 0, sizeof(complex_t) * kExtendedNumPartitions * PART_LEN1);
memset(aec->sde, 0, sizeof(complex_t) * PART_LEN1);
memset(aec->sxd, 0, sizeof(complex_t) * PART_LEN1);
memset(
aec->xfwBuf, 0, sizeof(complex_t) * kExtendedNumPartitions * PART_LEN1);
memset(aec->se, 0, sizeof(float) * PART_LEN1);
// To prevent numerical instability in the first block.
for (i = 0; i < PART_LEN1; i++) {
aec->sd[i] = 1;
}
for (i = 0; i < PART_LEN1; i++) {
aec->sx[i] = 1;
}
memset(aec->hNs, 0, sizeof(aec->hNs));
memset(aec->outBuf, 0, sizeof(float) * PART_LEN);
aec->hNlFbMin = 1;
aec->hNlFbLocalMin = 1;
aec->hNlXdAvgMin = 1;
aec->hNlNewMin = 0;
aec->hNlMinCtr = 0;
aec->overDrive = 2;
aec->overDriveSm = 2;
aec->delayIdx = 0;
aec->stNearState = 0;
aec->echoState = 0;
aec->divergeState = 0;
aec->seed = 777;
aec->delayEstCtr = 0;
// Metrics disabled by default
aec->metricsMode = 0;
InitMetrics(aec);
return 0;
}
void WebRtcAec_BufferFarendPartition(AecCore* aec, const float* farend) {
float fft[PART_LEN2];
float xf[2][PART_LEN1];
// Check if the buffer is full, and in that case flush the oldest data.
if (WebRtc_available_write(aec->far_buf) < 1) {
WebRtcAec_MoveFarReadPtr(aec, 1);
}
// Convert far-end partition to the frequency domain without windowing.
memcpy(fft, farend, sizeof(float) * PART_LEN2);
TimeToFrequency(fft, xf, 0);
WebRtc_WriteBuffer(aec->far_buf, &xf[0][0], 1);
// Convert far-end partition to the frequency domain with windowing.
memcpy(fft, farend, sizeof(float) * PART_LEN2);
TimeToFrequency(fft, xf, 1);
WebRtc_WriteBuffer(aec->far_buf_windowed, &xf[0][0], 1);
}
int WebRtcAec_MoveFarReadPtr(AecCore* aec, int elements) {
int elements_moved = MoveFarReadPtrWithoutSystemDelayUpdate(aec, elements);
aec->system_delay -= elements_moved * PART_LEN;
return elements_moved;
}
void WebRtcAec_ProcessFrames(AecCore* aec,
const float* const* nearend,
size_t num_bands,
size_t num_samples,
int knownDelay,
float* const* out) {
size_t i, j;
int out_elements = 0;
aec->frame_count++;
// For each frame the process is as follows:
// 1) If the system_delay indicates on being too small for processing a
// frame we stuff the buffer with enough data for 10 ms.
// 2 a) Adjust the buffer to the system delay, by moving the read pointer.
// b) Apply signal based delay correction, if we have detected poor AEC
// performance.
// 3) TODO(bjornv): Investigate if we need to add this:
// If we can't move read pointer due to buffer size limitations we
// flush/stuff the buffer.
// 4) Process as many partitions as possible.
// 5) Update the |system_delay| with respect to a full frame of FRAME_LEN
// samples. Even though we will have data left to process (we work with
// partitions) we consider updating a whole frame, since that's the
// amount of data we input and output in audio_processing.
// 6) Update the outputs.
// The AEC has two different delay estimation algorithms built in. The
// first relies on delay input values from the user and the amount of
// shifted buffer elements is controlled by |knownDelay|. This delay will
// give a guess on how much we need to shift far-end buffers to align with
// the near-end signal. The other delay estimation algorithm uses the
// far- and near-end signals to find the offset between them. This one
// (called "signal delay") is then used to fine tune the alignment, or
// simply compensate for errors in the system based one.
// Note that the two algorithms operate independently. Currently, we only
// allow one algorithm to be turned on.
assert(aec->num_bands == num_bands);
for (j = 0; j < num_samples; j+= FRAME_LEN) {
// TODO(bjornv): Change the near-end buffer handling to be the same as for
// far-end, that is, with a near_pre_buf.
// Buffer the near-end frame.
WebRtc_WriteBuffer(aec->nearFrBuf, &nearend[0][j], FRAME_LEN);
// For H band
for (i = 1; i < num_bands; ++i) {
WebRtc_WriteBuffer(aec->nearFrBufH[i - 1], &nearend[i][j], FRAME_LEN);
}
// 1) At most we process |aec->mult|+1 partitions in 10 ms. Make sure we
// have enough far-end data for that by stuffing the buffer if the
// |system_delay| indicates others.
if (aec->system_delay < FRAME_LEN) {
// We don't have enough data so we rewind 10 ms.
WebRtcAec_MoveFarReadPtr(aec, -(aec->mult + 1));
}
if (!aec->delay_agnostic_enabled) {
// 2 a) Compensate for a possible change in the system delay.
// TODO(bjornv): Investigate how we should round the delay difference;
// right now we know that incoming |knownDelay| is underestimated when
// it's less than |aec->knownDelay|. We therefore, round (-32) in that
// direction. In the other direction, we don't have this situation, but
// might flush one partition too little. This can cause non-causality,
// which should be investigated. Maybe, allow for a non-symmetric
// rounding, like -16.
int move_elements = (aec->knownDelay - knownDelay - 32) / PART_LEN;
int moved_elements =
MoveFarReadPtrWithoutSystemDelayUpdate(aec, move_elements);
aec->knownDelay -= moved_elements * PART_LEN;
} else {
// 2 b) Apply signal based delay correction.
int move_elements = SignalBasedDelayCorrection(aec);
int moved_elements =
MoveFarReadPtrWithoutSystemDelayUpdate(aec, move_elements);
int far_near_buffer_diff = WebRtc_available_read(aec->far_buf) -
WebRtc_available_read(aec->nearFrBuf) / PART_LEN;
WebRtc_SoftResetDelayEstimator(aec->delay_estimator, moved_elements);
WebRtc_SoftResetDelayEstimatorFarend(aec->delay_estimator_farend,
moved_elements);
aec->signal_delay_correction += moved_elements;
// If we rely on reported system delay values only, a buffer underrun here
// can never occur since we've taken care of that in 1) above. Here, we
// apply signal based delay correction and can therefore end up with
// buffer underruns since the delay estimation can be wrong. We therefore
// stuff the buffer with enough elements if needed.
if (far_near_buffer_diff < 0) {
WebRtcAec_MoveFarReadPtr(aec, far_near_buffer_diff);
}
}
// 4) Process as many blocks as possible.
while (WebRtc_available_read(aec->nearFrBuf) >= PART_LEN) {
ProcessBlock(aec);
}
// 5) Update system delay with respect to the entire frame.
aec->system_delay -= FRAME_LEN;
// 6) Update output frame.
// Stuff the out buffer if we have less than a frame to output.
// This should only happen for the first frame.
out_elements = (int)WebRtc_available_read(aec->outFrBuf);
if (out_elements < FRAME_LEN) {
WebRtc_MoveReadPtr(aec->outFrBuf, out_elements - FRAME_LEN);
for (i = 0; i < num_bands - 1; ++i) {
WebRtc_MoveReadPtr(aec->outFrBufH[i], out_elements - FRAME_LEN);
}
}
// Obtain an output frame.
WebRtc_ReadBuffer(aec->outFrBuf, NULL, &out[0][j], FRAME_LEN);
// For H bands.
for (i = 1; i < num_bands; ++i) {
WebRtc_ReadBuffer(aec->outFrBufH[i - 1], NULL, &out[i][j], FRAME_LEN);
}
}
}
int WebRtcAec_GetDelayMetricsCore(AecCore* self, int* median, int* std,
float* fraction_poor_delays) {
assert(self != NULL);
assert(median != NULL);
assert(std != NULL);
if (self->delay_logging_enabled == 0) {
// Logging disabled.
return -1;
}
if (self->delay_metrics_delivered == 0) {
UpdateDelayMetrics(self);
self->delay_metrics_delivered = 1;
}
*median = self->delay_median;
*std = self->delay_std;
*fraction_poor_delays = self->fraction_poor_delays;
return 0;
}
int WebRtcAec_echo_state(AecCore* self) { return self->echoState; }
void WebRtcAec_GetEchoStats(AecCore* self,
Stats* erl,
Stats* erle,
Stats* a_nlp) {
assert(erl != NULL);
assert(erle != NULL);
assert(a_nlp != NULL);
*erl = self->erl;
*erle = self->erle;
*a_nlp = self->aNlp;
}
#ifdef WEBRTC_AEC_DEBUG_DUMP
void* WebRtcAec_far_time_buf(AecCore* self) { return self->far_time_buf; }
#endif
void WebRtcAec_SetConfigCore(AecCore* self,
int nlp_mode,
int metrics_mode,
int delay_logging) {
assert(nlp_mode >= 0 && nlp_mode < 3);
self->nlp_mode = nlp_mode;
self->metricsMode = metrics_mode;
if (self->metricsMode) {
InitMetrics(self);
}
// Turn on delay logging if it is either set explicitly or if delay agnostic
// AEC is enabled (which requires delay estimates).
self->delay_logging_enabled = delay_logging || self->delay_agnostic_enabled;
if (self->delay_logging_enabled) {
memset(self->delay_histogram, 0, sizeof(self->delay_histogram));
}
}
void WebRtcAec_enable_delay_agnostic(AecCore* self, int enable) {
self->delay_agnostic_enabled = enable;
}
int WebRtcAec_delay_agnostic_enabled(AecCore* self) {
return self->delay_agnostic_enabled;
}
void WebRtcAec_enable_extended_filter(AecCore* self, int enable) {
self->extended_filter_enabled = enable;
self->num_partitions = enable ? kExtendedNumPartitions : kNormalNumPartitions;
// Update the delay estimator with filter length. See InitAEC() for details.
WebRtc_set_allowed_offset(self->delay_estimator, self->num_partitions / 2);
}
int WebRtcAec_extended_filter_enabled(AecCore* self) {
return self->extended_filter_enabled;
}
int WebRtcAec_system_delay(AecCore* self) { return self->system_delay; }
void WebRtcAec_SetSystemDelay(AecCore* self, int delay) {
assert(delay >= 0);
self->system_delay = delay;
}
|