summaryrefslogtreecommitdiffstats
path: root/audio/include/system/audio.h
blob: 3811813596bb115e719b0021508b27b2059d5813 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


#ifndef ANDROID_AUDIO_CORE_H
#define ANDROID_AUDIO_CORE_H

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <sys/cdefs.h>
#include <sys/types.h>

#include <cutils/bitops.h>

__BEGIN_DECLS

/* The macro FCC_2 highlights places where there are 2-channel assumptions.
 * This is typically due to legacy implementation of stereo input or output.
 * Search also for "2", "left", "right", "[0]", "[1]", ">> 16", "<< 16", etc.
 * Do not change this value.
 */
#define FCC_2 2     // FCC_2 = Fixed Channel Count 2

/* The macro FCC_8 highlights places where there are 8-channel assumptions.
 * This is typically due to audio mixer and resampler limitations.
 * Do not change this value without verifying all locations that use it.
 */
#define FCC_8 8     // FCC_8 = Fixed Channel Count 8

/* The enums were moved here mostly from
 * frameworks/base/include/media/AudioSystem.h
 */

/* device address used to refer to the standard remote submix */
#define AUDIO_REMOTE_SUBMIX_DEVICE_ADDRESS "0"

/* AudioFlinger and AudioPolicy services use I/O handles to identify audio sources and sinks */
typedef int audio_io_handle_t;
#define AUDIO_IO_HANDLE_NONE    0

/* Audio stream types */
typedef enum {
    /* These values must kept in sync with
     * frameworks/base/media/java/android/media/AudioSystem.java
     */
    AUDIO_STREAM_DEFAULT          = -1,
    AUDIO_STREAM_MIN              = 0,
    AUDIO_STREAM_VOICE_CALL       = 0,
    AUDIO_STREAM_SYSTEM           = 1,
    AUDIO_STREAM_RING             = 2,
    AUDIO_STREAM_MUSIC            = 3,
    AUDIO_STREAM_ALARM            = 4,
    AUDIO_STREAM_NOTIFICATION     = 5,
    AUDIO_STREAM_BLUETOOTH_SCO    = 6,
    AUDIO_STREAM_ENFORCED_AUDIBLE = 7, /* Sounds that cannot be muted by user
                                        * and must be routed to speaker
                                        */
    AUDIO_STREAM_DTMF             = 8,
    AUDIO_STREAM_TTS              = 9,  /* Transmitted Through Speaker.
                                         * Plays over speaker only, silent on other devices.
                                         */
    AUDIO_STREAM_ACCESSIBILITY    = 10, /* For accessibility talk back prompts */
    AUDIO_STREAM_REROUTING        = 11, /* For dynamic policy output mixes */
    AUDIO_STREAM_PATCH            = 12, /* For internal audio flinger tracks. Fixed volume */
    AUDIO_STREAM_PUBLIC_CNT       = AUDIO_STREAM_TTS + 1,
    AUDIO_STREAM_FOR_POLICY_CNT   = AUDIO_STREAM_PATCH, /* number of streams considered by
                                           audio policy for volume and routing */
    AUDIO_STREAM_CNT              = AUDIO_STREAM_PATCH + 1,
} audio_stream_type_t;

/* Do not change these values without updating their counterparts
 * in frameworks/base/media/java/android/media/AudioAttributes.java
 */
typedef enum {
    AUDIO_CONTENT_TYPE_UNKNOWN      = 0,
    AUDIO_CONTENT_TYPE_SPEECH       = 1,
    AUDIO_CONTENT_TYPE_MUSIC        = 2,
    AUDIO_CONTENT_TYPE_MOVIE        = 3,
    AUDIO_CONTENT_TYPE_SONIFICATION = 4,

    AUDIO_CONTENT_TYPE_CNT,
    AUDIO_CONTENT_TYPE_MAX          = AUDIO_CONTENT_TYPE_CNT - 1,
} audio_content_type_t;

/* Do not change these values without updating their counterparts
 * in frameworks/base/media/java/android/media/AudioAttributes.java
 */
typedef enum {
    AUDIO_USAGE_UNKNOWN                            = 0,
    AUDIO_USAGE_MEDIA                              = 1,
    AUDIO_USAGE_VOICE_COMMUNICATION                = 2,
    AUDIO_USAGE_VOICE_COMMUNICATION_SIGNALLING     = 3,
    AUDIO_USAGE_ALARM                              = 4,
    AUDIO_USAGE_NOTIFICATION                       = 5,
    AUDIO_USAGE_NOTIFICATION_TELEPHONY_RINGTONE    = 6,
    AUDIO_USAGE_NOTIFICATION_COMMUNICATION_REQUEST = 7,
    AUDIO_USAGE_NOTIFICATION_COMMUNICATION_INSTANT = 8,
    AUDIO_USAGE_NOTIFICATION_COMMUNICATION_DELAYED = 9,
    AUDIO_USAGE_NOTIFICATION_EVENT                 = 10,
    AUDIO_USAGE_ASSISTANCE_ACCESSIBILITY           = 11,
    AUDIO_USAGE_ASSISTANCE_NAVIGATION_GUIDANCE     = 12,
    AUDIO_USAGE_ASSISTANCE_SONIFICATION            = 13,
    AUDIO_USAGE_GAME                               = 14,
    AUDIO_USAGE_VIRTUAL_SOURCE                     = 15,

    AUDIO_USAGE_CNT,
    AUDIO_USAGE_MAX                                = AUDIO_USAGE_CNT - 1,
} audio_usage_t;

typedef uint32_t audio_flags_mask_t;

/* Do not change these values without updating their counterparts
 * in frameworks/base/media/java/android/media/AudioAttributes.java
 */
enum {
    AUDIO_FLAG_AUDIBILITY_ENFORCED        = 0x1,
    AUDIO_FLAG_SECURE                     = 0x2,
    AUDIO_FLAG_SCO                        = 0x4,
    AUDIO_FLAG_BEACON                     = 0x8,
    AUDIO_FLAG_HW_AV_SYNC                 = 0x10,
    AUDIO_FLAG_HW_HOTWORD                 = 0x20,
    AUDIO_FLAG_BYPASS_INTERRUPTION_POLICY = 0x40,
    AUDIO_FLAG_BYPASS_MUTE                = 0x80,
    AUDIO_FLAG_LOW_LATENCY                = 0x100,
};

/* Do not change these values without updating their counterparts
 * in frameworks/base/media/java/android/media/MediaRecorder.java,
 * frameworks/av/services/audiopolicy/AudioPolicyService.cpp,
 * and system/media/audio_effects/include/audio_effects/audio_effects_conf.h!
 */
typedef enum {
    AUDIO_SOURCE_DEFAULT             = 0,
    AUDIO_SOURCE_MIC                 = 1,
    AUDIO_SOURCE_VOICE_UPLINK        = 2,
    AUDIO_SOURCE_VOICE_DOWNLINK      = 3,
    AUDIO_SOURCE_VOICE_CALL          = 4,
    AUDIO_SOURCE_CAMCORDER           = 5,
    AUDIO_SOURCE_VOICE_RECOGNITION   = 6,
    AUDIO_SOURCE_VOICE_COMMUNICATION = 7,
    AUDIO_SOURCE_REMOTE_SUBMIX       = 8, /* Source for the mix to be presented remotely.      */
                                          /* An example of remote presentation is Wifi Display */
                                          /*  where a dongle attached to a TV can be used to   */
                                          /*  play the mix captured by this audio source.      */
    AUDIO_SOURCE_UNPROCESSED         = 9, /* Source for unprocessed sound.
                                             Usage examples include level measurement and raw
                                             signal analysis. */
    AUDIO_SOURCE_CNT,
    AUDIO_SOURCE_MAX                 = AUDIO_SOURCE_CNT - 1,
    AUDIO_SOURCE_FM_TUNER            = 1998,
    AUDIO_SOURCE_HOTWORD             = 1999, /* A low-priority, preemptible audio source for
                                                for background software hotword detection.
                                                Same tuning as AUDIO_SOURCE_VOICE_RECOGNITION.
                                                Used only internally to the framework. Not exposed
                                                at the audio HAL. */
} audio_source_t;

/* Audio attributes */
#define AUDIO_ATTRIBUTES_TAGS_MAX_SIZE 256
typedef struct {
    audio_content_type_t content_type;
    audio_usage_t        usage;
    audio_source_t       source;
    audio_flags_mask_t   flags;
    char                 tags[AUDIO_ATTRIBUTES_TAGS_MAX_SIZE]; /* UTF8 */
} audio_attributes_t;

/* special audio session values
 * do not need to have audio_unique_id_get_use(session) == AUDIO_UNIQUE_ID_USE_SESSION
 * (XXX: should this be living in the audio effects land?)
 */
typedef enum {
    /* session for effects attached to a particular output stream
     * (value must be less than 0)
     */
    AUDIO_SESSION_OUTPUT_STAGE = -1,

    /* session for effects applied to output mix. These effects can
     * be moved by audio policy manager to another output stream
     * (value must be 0)
     */
    AUDIO_SESSION_OUTPUT_MIX = 0,

    /* application does not specify an explicit session ID to be used,
     * and requests a new session ID to be allocated
     * TODO use unique values for AUDIO_SESSION_OUTPUT_MIX and AUDIO_SESSION_ALLOCATE,
     * after all uses have been updated from 0 to the appropriate symbol, and have been tested.
     * Corresponds to AudioManager.AUDIO_SESSION_ID_GENERATE and AudioSystem.AUDIO_SESSION_ALLOCATE.
     */
    AUDIO_SESSION_ALLOCATE = 0,

    /* For use with AudioRecord::start(), this indicates no trigger session.
     * It is also used with output tracks and patch tracks, which never have a session.
     */
    AUDIO_SESSION_NONE = 0,
} audio_session_t;

/* a unique ID allocated by AudioFlinger for use as an audio_io_handle_t, audio_session_t,
 * effect ID (int), audio_module_handle_t, and audio_patch_handle_t.
 * Audio port IDs (audio_port_handle_t) are allocated by AudioPolicy
 * in a different namespace than AudioFlinger unique IDs.
 */
typedef int audio_unique_id_t;

/* Possible uses for an audio_unique_id_t */
typedef enum {
    AUDIO_UNIQUE_ID_USE_UNSPECIFIED = 0,
    AUDIO_UNIQUE_ID_USE_SESSION = 1,    // for allocated sessions, not special AUDIO_SESSION_*
    AUDIO_UNIQUE_ID_USE_MODULE = 2,
    AUDIO_UNIQUE_ID_USE_EFFECT = 3,
    AUDIO_UNIQUE_ID_USE_PATCH = 4,
    AUDIO_UNIQUE_ID_USE_OUTPUT = 5,
    AUDIO_UNIQUE_ID_USE_INPUT = 6,
    // 7 is available
    AUDIO_UNIQUE_ID_USE_MAX = 8,  // must be a power-of-two
    AUDIO_UNIQUE_ID_USE_MASK = AUDIO_UNIQUE_ID_USE_MAX - 1
} audio_unique_id_use_t;

/* Return the use of an audio_unique_id_t */
static inline audio_unique_id_use_t audio_unique_id_get_use(audio_unique_id_t id)
{
    return (audio_unique_id_use_t) (id & AUDIO_UNIQUE_ID_USE_MASK);
}

/* Reserved audio_unique_id_t values.  FIXME: not a complete list. */
#define AUDIO_UNIQUE_ID_ALLOCATE AUDIO_SESSION_ALLOCATE

/* Audio sub formats (see enum audio_format). */

/* PCM sub formats */
typedef enum {
    /* All of these are in native byte order */
    AUDIO_FORMAT_PCM_SUB_16_BIT          = 0x1, /* DO NOT CHANGE - PCM signed 16 bits */
    AUDIO_FORMAT_PCM_SUB_8_BIT           = 0x2, /* DO NOT CHANGE - PCM unsigned 8 bits */
    AUDIO_FORMAT_PCM_SUB_32_BIT          = 0x3, /* PCM signed .31 fixed point */
    AUDIO_FORMAT_PCM_SUB_8_24_BIT        = 0x4, /* PCM signed 8.23 fixed point */
    AUDIO_FORMAT_PCM_SUB_FLOAT           = 0x5, /* PCM single-precision floating point */
    AUDIO_FORMAT_PCM_SUB_24_BIT_PACKED   = 0x6, /* PCM signed .23 fixed point packed in 3 bytes */
} audio_format_pcm_sub_fmt_t;

/* The audio_format_*_sub_fmt_t declarations are not currently used */

/* MP3 sub format field definition : can use 11 LSBs in the same way as MP3
 * frame header to specify bit rate, stereo mode, version...
 */
typedef enum {
    AUDIO_FORMAT_MP3_SUB_NONE            = 0x0,
} audio_format_mp3_sub_fmt_t;

/* AMR NB/WB sub format field definition: specify frame block interleaving,
 * bandwidth efficient or octet aligned, encoding mode for recording...
 */
typedef enum {
    AUDIO_FORMAT_AMR_SUB_NONE            = 0x0,
} audio_format_amr_sub_fmt_t;

/* AAC sub format field definition: specify profile or bitrate for recording... */
typedef enum {
    AUDIO_FORMAT_AAC_SUB_MAIN            = 0x1,
    AUDIO_FORMAT_AAC_SUB_LC              = 0x2,
    AUDIO_FORMAT_AAC_SUB_SSR             = 0x4,
    AUDIO_FORMAT_AAC_SUB_LTP             = 0x8,
    AUDIO_FORMAT_AAC_SUB_HE_V1           = 0x10,
    AUDIO_FORMAT_AAC_SUB_SCALABLE        = 0x20,
    AUDIO_FORMAT_AAC_SUB_ERLC            = 0x40,
    AUDIO_FORMAT_AAC_SUB_LD              = 0x80,
    AUDIO_FORMAT_AAC_SUB_HE_V2           = 0x100,
    AUDIO_FORMAT_AAC_SUB_ELD             = 0x200,
} audio_format_aac_sub_fmt_t;

/* VORBIS sub format field definition: specify quality for recording... */
typedef enum {
    AUDIO_FORMAT_VORBIS_SUB_NONE         = 0x0,
} audio_format_vorbis_sub_fmt_t;


/* Audio format  is a 32-bit word that consists of:
 *   main format field (upper 8 bits)
 *   sub format field (lower 24 bits).
 *
 * The main format indicates the main codec type. The sub format field
 * indicates options and parameters for each format. The sub format is mainly
 * used for record to indicate for instance the requested bitrate or profile.
 * It can also be used for certain formats to give informations not present in
 * the encoded audio stream (e.g. octet alignement for AMR).
 */
typedef enum {
    AUDIO_FORMAT_INVALID             = 0xFFFFFFFFUL,
    AUDIO_FORMAT_DEFAULT             = 0,
    AUDIO_FORMAT_PCM                 = 0x00000000UL, /* DO NOT CHANGE */
    AUDIO_FORMAT_MP3                 = 0x01000000UL,
    AUDIO_FORMAT_AMR_NB              = 0x02000000UL,
    AUDIO_FORMAT_AMR_WB              = 0x03000000UL,
    AUDIO_FORMAT_AAC                 = 0x04000000UL,
    AUDIO_FORMAT_HE_AAC_V1           = 0x05000000UL, /* Deprecated, Use AUDIO_FORMAT_AAC_HE_V1*/
    AUDIO_FORMAT_HE_AAC_V2           = 0x06000000UL, /* Deprecated, Use AUDIO_FORMAT_AAC_HE_V2*/
    AUDIO_FORMAT_VORBIS              = 0x07000000UL,
    AUDIO_FORMAT_OPUS                = 0x08000000UL,
    AUDIO_FORMAT_AC3                 = 0x09000000UL,
    AUDIO_FORMAT_E_AC3               = 0x0A000000UL,
    AUDIO_FORMAT_DTS                 = 0x0B000000UL,
    AUDIO_FORMAT_DTS_HD              = 0x0C000000UL,
    // IEC61937 is encoded audio wrapped in 16-bit PCM.
    AUDIO_FORMAT_IEC61937            = 0x0D000000UL,
    AUDIO_FORMAT_EVRC                = 0x10000000UL,
    AUDIO_FORMAT_QCELP               = 0x11000000UL,
    AUDIO_FORMAT_WMA                 = 0x12000000UL,
    AUDIO_FORMAT_WMA_PRO             = 0x13000000UL,
    AUDIO_FORMAT_AAC_ADIF            = 0x14000000UL,
    AUDIO_FORMAT_EVRCB               = 0x15000000UL,
    AUDIO_FORMAT_EVRCWB              = 0x16000000UL,
    AUDIO_FORMAT_AMR_WB_PLUS         = 0x17000000UL,
    AUDIO_FORMAT_MP2                 = 0x18000000UL,
    AUDIO_FORMAT_EVRCNW              = 0x19000000UL,
    AUDIO_FORMAT_PCM_OFFLOAD         = 0x1A000000UL,
    AUDIO_FORMAT_FLAC                = 0x1B000000UL,
    AUDIO_FORMAT_ALAC                = 0x1C000000UL,
    AUDIO_FORMAT_APE                 = 0x1D000000UL,
    AUDIO_FORMAT_AAC_ADTS            = 0x1E000000UL,
    AUDIO_FORMAT_DSD                 = 0x1F000000UL,
    AUDIO_FORMAT_MAIN_MASK           = 0xFF000000UL, /* Deprecated. Use audio_get_main_format() */
    AUDIO_FORMAT_SUB_MASK            = 0x00FFFFFFUL,

    /* Aliases */
    /* note != AudioFormat.ENCODING_PCM_16BIT */
    AUDIO_FORMAT_PCM_16_BIT          = (AUDIO_FORMAT_PCM |
                                        AUDIO_FORMAT_PCM_SUB_16_BIT),
    /* note != AudioFormat.ENCODING_PCM_8BIT */
    AUDIO_FORMAT_PCM_8_BIT           = (AUDIO_FORMAT_PCM |
                                        AUDIO_FORMAT_PCM_SUB_8_BIT),
    AUDIO_FORMAT_PCM_32_BIT          = (AUDIO_FORMAT_PCM |
                                        AUDIO_FORMAT_PCM_SUB_32_BIT),
    AUDIO_FORMAT_PCM_8_24_BIT        = (AUDIO_FORMAT_PCM |
                                        AUDIO_FORMAT_PCM_SUB_8_24_BIT),
    AUDIO_FORMAT_PCM_FLOAT           = (AUDIO_FORMAT_PCM |
                                        AUDIO_FORMAT_PCM_SUB_FLOAT),
    AUDIO_FORMAT_PCM_24_BIT_PACKED   = (AUDIO_FORMAT_PCM |
                                        AUDIO_FORMAT_PCM_SUB_24_BIT_PACKED),
    AUDIO_FORMAT_AAC_MAIN            = (AUDIO_FORMAT_AAC |
                                        AUDIO_FORMAT_AAC_SUB_MAIN),
    AUDIO_FORMAT_AAC_LC              = (AUDIO_FORMAT_AAC |
                                        AUDIO_FORMAT_AAC_SUB_LC),
    AUDIO_FORMAT_AAC_SSR             = (AUDIO_FORMAT_AAC |
                                        AUDIO_FORMAT_AAC_SUB_SSR),
    AUDIO_FORMAT_AAC_LTP             = (AUDIO_FORMAT_AAC |
                                        AUDIO_FORMAT_AAC_SUB_LTP),
    AUDIO_FORMAT_AAC_HE_V1           = (AUDIO_FORMAT_AAC |
                                        AUDIO_FORMAT_AAC_SUB_HE_V1),
    AUDIO_FORMAT_AAC_SCALABLE        = (AUDIO_FORMAT_AAC |
                                        AUDIO_FORMAT_AAC_SUB_SCALABLE),
    AUDIO_FORMAT_AAC_ERLC            = (AUDIO_FORMAT_AAC |
                                        AUDIO_FORMAT_AAC_SUB_ERLC),
    AUDIO_FORMAT_AAC_LD              = (AUDIO_FORMAT_AAC |
                                        AUDIO_FORMAT_AAC_SUB_LD),
    AUDIO_FORMAT_AAC_HE_V2           = (AUDIO_FORMAT_AAC |
                                        AUDIO_FORMAT_AAC_SUB_HE_V2),
    AUDIO_FORMAT_AAC_ELD             = (AUDIO_FORMAT_AAC |
                                        AUDIO_FORMAT_AAC_SUB_ELD),
    AUDIO_FORMAT_AAC_ADTS_MAIN       = (AUDIO_FORMAT_AAC_ADTS |
                                        AUDIO_FORMAT_AAC_SUB_MAIN),
    AUDIO_FORMAT_AAC_ADTS_LC         = (AUDIO_FORMAT_AAC_ADTS |
                                        AUDIO_FORMAT_AAC_SUB_LC),
    AUDIO_FORMAT_AAC_ADTS_SSR        = (AUDIO_FORMAT_AAC_ADTS |
                                        AUDIO_FORMAT_AAC_SUB_SSR),
    AUDIO_FORMAT_AAC_ADTS_LTP        = (AUDIO_FORMAT_AAC_ADTS |
                                        AUDIO_FORMAT_AAC_SUB_LTP),
    AUDIO_FORMAT_AAC_ADTS_HE_V1      = (AUDIO_FORMAT_AAC_ADTS |
                                        AUDIO_FORMAT_AAC_SUB_HE_V1),
    AUDIO_FORMAT_AAC_ADTS_SCALABLE   = (AUDIO_FORMAT_AAC_ADTS |
                                        AUDIO_FORMAT_AAC_SUB_SCALABLE),
    AUDIO_FORMAT_AAC_ADTS_ERLC       = (AUDIO_FORMAT_AAC_ADTS |
                                        AUDIO_FORMAT_AAC_SUB_ERLC),
    AUDIO_FORMAT_AAC_ADTS_LD         = (AUDIO_FORMAT_AAC_ADTS |
                                        AUDIO_FORMAT_AAC_SUB_LD),
    AUDIO_FORMAT_AAC_ADTS_HE_V2      = (AUDIO_FORMAT_AAC_ADTS |
                                        AUDIO_FORMAT_AAC_SUB_HE_V2),
    AUDIO_FORMAT_AAC_ADTS_ELD        = (AUDIO_FORMAT_AAC_ADTS |
                                        AUDIO_FORMAT_AAC_SUB_ELD),
    /*Offload PCM formats*/
    AUDIO_FORMAT_PCM_16_BIT_OFFLOAD  = (AUDIO_FORMAT_PCM_OFFLOAD |
                                        AUDIO_FORMAT_PCM_SUB_16_BIT),
    AUDIO_FORMAT_PCM_24_BIT_OFFLOAD  = (AUDIO_FORMAT_PCM_OFFLOAD |
                                        AUDIO_FORMAT_PCM_SUB_8_24_BIT),
} audio_format_t;

/* For the channel mask for position assignment representation */
enum {

/* These can be a complete audio_channel_mask_t. */

    AUDIO_CHANNEL_NONE                      = 0x0,
    AUDIO_CHANNEL_INVALID                   = 0xC0000000,

/* These can be the bits portion of an audio_channel_mask_t
 * with representation AUDIO_CHANNEL_REPRESENTATION_POSITION.
 * Using these bits as a complete audio_channel_mask_t is deprecated.
 */

    /* output channels */
    AUDIO_CHANNEL_OUT_FRONT_LEFT            = 0x1,
    AUDIO_CHANNEL_OUT_FRONT_RIGHT           = 0x2,
    AUDIO_CHANNEL_OUT_FRONT_CENTER          = 0x4,
    AUDIO_CHANNEL_OUT_LOW_FREQUENCY         = 0x8,
    AUDIO_CHANNEL_OUT_BACK_LEFT             = 0x10,
    AUDIO_CHANNEL_OUT_BACK_RIGHT            = 0x20,
    AUDIO_CHANNEL_OUT_FRONT_LEFT_OF_CENTER  = 0x40,
    AUDIO_CHANNEL_OUT_FRONT_RIGHT_OF_CENTER = 0x80,
    AUDIO_CHANNEL_OUT_BACK_CENTER           = 0x100,
    AUDIO_CHANNEL_OUT_SIDE_LEFT             = 0x200,
    AUDIO_CHANNEL_OUT_SIDE_RIGHT            = 0x400,
    AUDIO_CHANNEL_OUT_TOP_CENTER            = 0x800,
    AUDIO_CHANNEL_OUT_TOP_FRONT_LEFT        = 0x1000,
    AUDIO_CHANNEL_OUT_TOP_FRONT_CENTER      = 0x2000,
    AUDIO_CHANNEL_OUT_TOP_FRONT_RIGHT       = 0x4000,
    AUDIO_CHANNEL_OUT_TOP_BACK_LEFT         = 0x8000,
    AUDIO_CHANNEL_OUT_TOP_BACK_CENTER       = 0x10000,
    AUDIO_CHANNEL_OUT_TOP_BACK_RIGHT        = 0x20000,

/* TODO: should these be considered complete channel masks, or only bits? */

    AUDIO_CHANNEL_OUT_MONO     = AUDIO_CHANNEL_OUT_FRONT_LEFT,
    AUDIO_CHANNEL_OUT_STEREO   = (AUDIO_CHANNEL_OUT_FRONT_LEFT |
                                  AUDIO_CHANNEL_OUT_FRONT_RIGHT),
    AUDIO_CHANNEL_OUT_2POINT1  = (AUDIO_CHANNEL_OUT_FRONT_LEFT |
                                  AUDIO_CHANNEL_OUT_FRONT_RIGHT |
                                  AUDIO_CHANNEL_OUT_FRONT_CENTER),
    AUDIO_CHANNEL_OUT_QUAD     = (AUDIO_CHANNEL_OUT_FRONT_LEFT |
                                  AUDIO_CHANNEL_OUT_FRONT_RIGHT |
                                  AUDIO_CHANNEL_OUT_BACK_LEFT |
                                  AUDIO_CHANNEL_OUT_BACK_RIGHT),
    AUDIO_CHANNEL_OUT_QUAD_BACK = AUDIO_CHANNEL_OUT_QUAD,
    /* like AUDIO_CHANNEL_OUT_QUAD_BACK with *_SIDE_* instead of *_BACK_* */
    AUDIO_CHANNEL_OUT_QUAD_SIDE = (AUDIO_CHANNEL_OUT_FRONT_LEFT |
                                  AUDIO_CHANNEL_OUT_FRONT_RIGHT |
                                  AUDIO_CHANNEL_OUT_SIDE_LEFT |
                                  AUDIO_CHANNEL_OUT_SIDE_RIGHT),
    AUDIO_CHANNEL_OUT_SURROUND = (AUDIO_CHANNEL_OUT_FRONT_LEFT |
                                  AUDIO_CHANNEL_OUT_FRONT_RIGHT |
                                  AUDIO_CHANNEL_OUT_FRONT_CENTER |
                                  AUDIO_CHANNEL_OUT_BACK_CENTER),
    AUDIO_CHANNEL_OUT_PENTA =    (AUDIO_CHANNEL_OUT_QUAD |
                                  AUDIO_CHANNEL_OUT_FRONT_CENTER),
    AUDIO_CHANNEL_OUT_5POINT1  = (AUDIO_CHANNEL_OUT_FRONT_LEFT |
                                  AUDIO_CHANNEL_OUT_FRONT_RIGHT |
                                  AUDIO_CHANNEL_OUT_FRONT_CENTER |
                                  AUDIO_CHANNEL_OUT_LOW_FREQUENCY |
                                  AUDIO_CHANNEL_OUT_BACK_LEFT |
                                  AUDIO_CHANNEL_OUT_BACK_RIGHT),
    AUDIO_CHANNEL_OUT_5POINT1_BACK = AUDIO_CHANNEL_OUT_5POINT1,
    /* like AUDIO_CHANNEL_OUT_5POINT1_BACK with *_SIDE_* instead of *_BACK_* */
    AUDIO_CHANNEL_OUT_5POINT1_SIDE = (AUDIO_CHANNEL_OUT_FRONT_LEFT |
                                  AUDIO_CHANNEL_OUT_FRONT_RIGHT |
                                  AUDIO_CHANNEL_OUT_FRONT_CENTER |
                                  AUDIO_CHANNEL_OUT_LOW_FREQUENCY |
                                  AUDIO_CHANNEL_OUT_SIDE_LEFT |
                                  AUDIO_CHANNEL_OUT_SIDE_RIGHT),
    AUDIO_CHANNEL_OUT_6POINT1  = (AUDIO_CHANNEL_OUT_FRONT_LEFT |
                                  AUDIO_CHANNEL_OUT_FRONT_RIGHT |
                                  AUDIO_CHANNEL_OUT_FRONT_CENTER |
                                  AUDIO_CHANNEL_OUT_LOW_FREQUENCY |
                                  AUDIO_CHANNEL_OUT_BACK_LEFT |
                                  AUDIO_CHANNEL_OUT_BACK_RIGHT |
                                  AUDIO_CHANNEL_OUT_BACK_CENTER),
    // matches the correct AudioFormat.CHANNEL_OUT_7POINT1_SURROUND definition for 7.1
    AUDIO_CHANNEL_OUT_7POINT1  = (AUDIO_CHANNEL_OUT_FRONT_LEFT |
                                  AUDIO_CHANNEL_OUT_FRONT_RIGHT |
                                  AUDIO_CHANNEL_OUT_FRONT_CENTER |
                                  AUDIO_CHANNEL_OUT_LOW_FREQUENCY |
                                  AUDIO_CHANNEL_OUT_BACK_LEFT |
                                  AUDIO_CHANNEL_OUT_BACK_RIGHT |
                                  AUDIO_CHANNEL_OUT_SIDE_LEFT |
                                  AUDIO_CHANNEL_OUT_SIDE_RIGHT),
    AUDIO_CHANNEL_OUT_ALL      = (AUDIO_CHANNEL_OUT_FRONT_LEFT |
                                  AUDIO_CHANNEL_OUT_FRONT_RIGHT |
                                  AUDIO_CHANNEL_OUT_FRONT_CENTER |
                                  AUDIO_CHANNEL_OUT_LOW_FREQUENCY |
                                  AUDIO_CHANNEL_OUT_BACK_LEFT |
                                  AUDIO_CHANNEL_OUT_BACK_RIGHT |
                                  AUDIO_CHANNEL_OUT_FRONT_LEFT_OF_CENTER |
                                  AUDIO_CHANNEL_OUT_FRONT_RIGHT_OF_CENTER |
                                  AUDIO_CHANNEL_OUT_BACK_CENTER|
                                  AUDIO_CHANNEL_OUT_SIDE_LEFT|
                                  AUDIO_CHANNEL_OUT_SIDE_RIGHT|
                                  AUDIO_CHANNEL_OUT_TOP_CENTER|
                                  AUDIO_CHANNEL_OUT_TOP_FRONT_LEFT|
                                  AUDIO_CHANNEL_OUT_TOP_FRONT_CENTER|
                                  AUDIO_CHANNEL_OUT_TOP_FRONT_RIGHT|
                                  AUDIO_CHANNEL_OUT_TOP_BACK_LEFT|
                                  AUDIO_CHANNEL_OUT_TOP_BACK_CENTER|
                                  AUDIO_CHANNEL_OUT_TOP_BACK_RIGHT),

/* These are bits only, not complete values */

    /* input channels */
    AUDIO_CHANNEL_IN_LEFT            = 0x4,
    AUDIO_CHANNEL_IN_RIGHT           = 0x8,
    AUDIO_CHANNEL_IN_FRONT           = 0x10,
    AUDIO_CHANNEL_IN_BACK            = 0x20,
    AUDIO_CHANNEL_IN_LEFT_PROCESSED  = 0x40,
    AUDIO_CHANNEL_IN_RIGHT_PROCESSED = 0x80,
    AUDIO_CHANNEL_IN_FRONT_PROCESSED = 0x100,
    AUDIO_CHANNEL_IN_BACK_PROCESSED  = 0x200,
    AUDIO_CHANNEL_IN_PRESSURE        = 0x400,
    AUDIO_CHANNEL_IN_X_AXIS          = 0x800,
    AUDIO_CHANNEL_IN_Y_AXIS          = 0x1000,
    AUDIO_CHANNEL_IN_Z_AXIS          = 0x2000,
    AUDIO_CHANNEL_IN_VOICE_UPLINK    = 0x4000,
    AUDIO_CHANNEL_IN_VOICE_DNLINK    = 0x8000,

/* TODO: should these be considered complete channel masks, or only bits, or deprecated? */

    AUDIO_CHANNEL_IN_MONO   = AUDIO_CHANNEL_IN_FRONT,
    AUDIO_CHANNEL_IN_STEREO = (AUDIO_CHANNEL_IN_LEFT | AUDIO_CHANNEL_IN_RIGHT),
    AUDIO_CHANNEL_IN_FRONT_BACK = (AUDIO_CHANNEL_IN_FRONT | AUDIO_CHANNEL_IN_BACK),
    AUDIO_CHANNEL_IN_5POINT1 = (AUDIO_CHANNEL_IN_LEFT |
                               AUDIO_CHANNEL_IN_RIGHT |
                               AUDIO_CHANNEL_IN_FRONT |
                               AUDIO_CHANNEL_IN_BACK |
                               AUDIO_CHANNEL_IN_LEFT_PROCESSED |
                               AUDIO_CHANNEL_IN_RIGHT_PROCESSED),
    AUDIO_CHANNEL_IN_VOICE_UPLINK_MONO = (AUDIO_CHANNEL_IN_VOICE_UPLINK | AUDIO_CHANNEL_IN_MONO),
    AUDIO_CHANNEL_IN_VOICE_DNLINK_MONO = (AUDIO_CHANNEL_IN_VOICE_DNLINK | AUDIO_CHANNEL_IN_MONO),
    AUDIO_CHANNEL_IN_VOICE_CALL_MONO   = (AUDIO_CHANNEL_IN_VOICE_UPLINK_MONO | AUDIO_CHANNEL_IN_VOICE_DNLINK_MONO),
    AUDIO_CHANNEL_IN_ALL    = (AUDIO_CHANNEL_IN_LEFT |
                               AUDIO_CHANNEL_IN_RIGHT |
                               AUDIO_CHANNEL_IN_FRONT |
                               AUDIO_CHANNEL_IN_BACK|
                               AUDIO_CHANNEL_IN_LEFT_PROCESSED |
                               AUDIO_CHANNEL_IN_RIGHT_PROCESSED |
                               AUDIO_CHANNEL_IN_FRONT_PROCESSED |
                               AUDIO_CHANNEL_IN_BACK_PROCESSED|
                               AUDIO_CHANNEL_IN_PRESSURE |
                               AUDIO_CHANNEL_IN_X_AXIS |
                               AUDIO_CHANNEL_IN_Y_AXIS |
                               AUDIO_CHANNEL_IN_Z_AXIS |
                               AUDIO_CHANNEL_IN_VOICE_UPLINK |
                               AUDIO_CHANNEL_IN_VOICE_DNLINK),
};

/* A channel mask per se only defines the presence or absence of a channel, not the order.
 * But see AUDIO_INTERLEAVE_* below for the platform convention of order.
 *
 * audio_channel_mask_t is an opaque type and its internal layout should not
 * be assumed as it may change in the future.
 * Instead, always use the functions declared in this header to examine.
 *
 * These are the current representations:
 *
 *   AUDIO_CHANNEL_REPRESENTATION_POSITION
 *     is a channel mask representation for position assignment.
 *     Each low-order bit corresponds to the spatial position of a transducer (output),
 *     or interpretation of channel (input).
 *     The user of a channel mask needs to know the context of whether it is for output or input.
 *     The constants AUDIO_CHANNEL_OUT_* or AUDIO_CHANNEL_IN_* apply to the bits portion.
 *     It is not permitted for no bits to be set.
 *
 *   AUDIO_CHANNEL_REPRESENTATION_INDEX
 *     is a channel mask representation for index assignment.
 *     Each low-order bit corresponds to a selected channel.
 *     There is no platform interpretation of the various bits.
 *     There is no concept of output or input.
 *     It is not permitted for no bits to be set.
 *
 * All other representations are reserved for future use.
 *
 * Warning: current representation distinguishes between input and output, but this will not the be
 * case in future revisions of the platform. Wherever there is an ambiguity between input and output
 * that is currently resolved by checking the channel mask, the implementer should look for ways to
 * fix it with additional information outside of the mask.
 */
typedef uint32_t audio_channel_mask_t;

/* Maximum number of channels for all representations */
#define AUDIO_CHANNEL_COUNT_MAX             30

/* log(2) of maximum number of representations, not part of public API */
#define AUDIO_CHANNEL_REPRESENTATION_LOG2   2

/* Representations */
typedef enum {
    AUDIO_CHANNEL_REPRESENTATION_POSITION    = 0,    // must be zero for compatibility
    // 1 is reserved for future use
    AUDIO_CHANNEL_REPRESENTATION_INDEX       = 2,
    // 3 is reserved for future use
} audio_channel_representation_t;

/* The channel index masks defined here are the canonical masks for 1 to 8 channel
 * endpoints and apply to both source and sink.
 */
enum {
    AUDIO_CHANNEL_INDEX_HDR  = AUDIO_CHANNEL_REPRESENTATION_INDEX << AUDIO_CHANNEL_COUNT_MAX,
    AUDIO_CHANNEL_INDEX_MASK_1 =  AUDIO_CHANNEL_INDEX_HDR | ((1 << 1) - 1),
    AUDIO_CHANNEL_INDEX_MASK_2 =  AUDIO_CHANNEL_INDEX_HDR | ((1 << 2) - 1),
    AUDIO_CHANNEL_INDEX_MASK_3 =  AUDIO_CHANNEL_INDEX_HDR | ((1 << 3) - 1),
    AUDIO_CHANNEL_INDEX_MASK_4 =  AUDIO_CHANNEL_INDEX_HDR | ((1 << 4) - 1),
    AUDIO_CHANNEL_INDEX_MASK_5 =  AUDIO_CHANNEL_INDEX_HDR | ((1 << 5) - 1),
    AUDIO_CHANNEL_INDEX_MASK_6 =  AUDIO_CHANNEL_INDEX_HDR | ((1 << 6) - 1),
    AUDIO_CHANNEL_INDEX_MASK_7 =  AUDIO_CHANNEL_INDEX_HDR | ((1 << 7) - 1),
    AUDIO_CHANNEL_INDEX_MASK_8 =  AUDIO_CHANNEL_INDEX_HDR | ((1 << 8) - 1),
    // FIXME FCC_8
};

/* The return value is undefined if the channel mask is invalid. */
static inline uint32_t audio_channel_mask_get_bits(audio_channel_mask_t channel)
{
    return channel & ((1 << AUDIO_CHANNEL_COUNT_MAX) - 1);
}

/* The return value is undefined if the channel mask is invalid. */
static inline audio_channel_representation_t audio_channel_mask_get_representation(
        audio_channel_mask_t channel)
{
    // The right shift should be sufficient, but also "and" for safety in case mask is not 32 bits
    return (audio_channel_representation_t)
            ((channel >> AUDIO_CHANNEL_COUNT_MAX) & ((1 << AUDIO_CHANNEL_REPRESENTATION_LOG2) - 1));
}

/* Returns true if the channel mask is valid,
 * or returns false for AUDIO_CHANNEL_NONE, AUDIO_CHANNEL_INVALID, and other invalid values.
 * This function is unable to determine whether a channel mask for position assignment
 * is invalid because an output mask has an invalid output bit set,
 * or because an input mask has an invalid input bit set.
 * All other APIs that take a channel mask assume that it is valid.
 */
static inline bool audio_channel_mask_is_valid(audio_channel_mask_t channel)
{
    uint32_t bits = audio_channel_mask_get_bits(channel);
    audio_channel_representation_t representation = audio_channel_mask_get_representation(channel);
    switch (representation) {
    case AUDIO_CHANNEL_REPRESENTATION_POSITION:
    case AUDIO_CHANNEL_REPRESENTATION_INDEX:
        break;
    default:
        bits = 0;
        break;
    }
    return bits != 0;
}

/* Not part of public API */
static inline audio_channel_mask_t audio_channel_mask_from_representation_and_bits(
        audio_channel_representation_t representation, uint32_t bits)
{
    return (audio_channel_mask_t) ((representation << AUDIO_CHANNEL_COUNT_MAX) | bits);
}

/* Expresses the convention when stereo audio samples are stored interleaved
 * in an array.  This should improve readability by allowing code to use
 * symbolic indices instead of hard-coded [0] and [1].
 *
 * For multi-channel beyond stereo, the platform convention is that channels
 * are interleaved in order from least significant channel mask bit
 * to most significant channel mask bit, with unused bits skipped.
 * Any exceptions to this convention will be noted at the appropriate API.
 */
enum {
    AUDIO_INTERLEAVE_LEFT   = 0,
    AUDIO_INTERLEAVE_RIGHT  = 1,
};

typedef enum {
    AUDIO_MODE_INVALID          = -2,
    AUDIO_MODE_CURRENT          = -1,
    AUDIO_MODE_NORMAL           = 0,
    AUDIO_MODE_RINGTONE         = 1,
    AUDIO_MODE_IN_CALL          = 2,
    AUDIO_MODE_IN_COMMUNICATION = 3,

    AUDIO_MODE_CNT,
    AUDIO_MODE_MAX              = AUDIO_MODE_CNT - 1,
} audio_mode_t;

/* This enum is deprecated */
typedef enum {
    AUDIO_IN_ACOUSTICS_NONE          = 0,
    AUDIO_IN_ACOUSTICS_AGC_ENABLE    = 0x0001,
    AUDIO_IN_ACOUSTICS_AGC_DISABLE   = 0,
    AUDIO_IN_ACOUSTICS_NS_ENABLE     = 0x0002,
    AUDIO_IN_ACOUSTICS_NS_DISABLE    = 0,
    AUDIO_IN_ACOUSTICS_TX_IIR_ENABLE = 0x0004,
    AUDIO_IN_ACOUSTICS_TX_DISABLE    = 0,
} audio_in_acoustics_t;

enum {
    AUDIO_DEVICE_NONE                          = 0x0,
    /* reserved bits */
    AUDIO_DEVICE_BIT_IN                        = 0x80000000,
    AUDIO_DEVICE_BIT_DEFAULT                   = 0x40000000,
    /* output devices */
    AUDIO_DEVICE_OUT_EARPIECE                  = 0x1,
    AUDIO_DEVICE_OUT_SPEAKER                   = 0x2,
    AUDIO_DEVICE_OUT_WIRED_HEADSET             = 0x4,
    AUDIO_DEVICE_OUT_WIRED_HEADPHONE           = 0x8,
    AUDIO_DEVICE_OUT_BLUETOOTH_SCO             = 0x10,
    AUDIO_DEVICE_OUT_BLUETOOTH_SCO_HEADSET     = 0x20,
    AUDIO_DEVICE_OUT_BLUETOOTH_SCO_CARKIT      = 0x40,
    AUDIO_DEVICE_OUT_BLUETOOTH_A2DP            = 0x80,
    AUDIO_DEVICE_OUT_BLUETOOTH_A2DP_HEADPHONES = 0x100,
    AUDIO_DEVICE_OUT_BLUETOOTH_A2DP_SPEAKER    = 0x200,
    AUDIO_DEVICE_OUT_AUX_DIGITAL               = 0x400,
    AUDIO_DEVICE_OUT_HDMI                      = AUDIO_DEVICE_OUT_AUX_DIGITAL,
    /* uses an analog connection (multiplexed over the USB connector pins for instance) */
    AUDIO_DEVICE_OUT_ANLG_DOCK_HEADSET         = 0x800,
    AUDIO_DEVICE_OUT_DGTL_DOCK_HEADSET         = 0x1000,
    /* USB accessory mode: your Android device is a USB device and the dock is a USB host */
    AUDIO_DEVICE_OUT_USB_ACCESSORY             = 0x2000,
    /* USB host mode: your Android device is a USB host and the dock is a USB device */
    AUDIO_DEVICE_OUT_USB_DEVICE                = 0x4000,
    AUDIO_DEVICE_OUT_REMOTE_SUBMIX             = 0x8000,
    /* Telephony voice TX path */
    AUDIO_DEVICE_OUT_TELEPHONY_TX              = 0x10000,
    /* Analog jack with line impedance detected */
    AUDIO_DEVICE_OUT_LINE                      = 0x20000,
    /* HDMI Audio Return Channel */
    AUDIO_DEVICE_OUT_HDMI_ARC                  = 0x40000,
    /* S/PDIF out */
    AUDIO_DEVICE_OUT_SPDIF                     = 0x80000,
    /* FM transmitter out */
    AUDIO_DEVICE_OUT_FM                        = 0x100000,
    /* Line out for av devices */
    AUDIO_DEVICE_OUT_AUX_LINE                  = 0x200000,
    /* limited-output speaker device for acoustic safety */
    AUDIO_DEVICE_OUT_SPEAKER_SAFE              = 0x400000,
    AUDIO_DEVICE_OUT_IP                        = 0x800000,
    /* audio bus implemented by the audio system (e.g an MOST stereo channel) */
    AUDIO_DEVICE_OUT_BUS                       = 0x1000000,
    AUDIO_DEVICE_OUT_PROXY                     = 0x2000000,
    AUDIO_DEVICE_OUT_DEFAULT                   = AUDIO_DEVICE_BIT_DEFAULT,
    AUDIO_DEVICE_OUT_ALL      = (AUDIO_DEVICE_OUT_EARPIECE |
                                 AUDIO_DEVICE_OUT_SPEAKER |
                                 AUDIO_DEVICE_OUT_WIRED_HEADSET |
                                 AUDIO_DEVICE_OUT_WIRED_HEADPHONE |
                                 AUDIO_DEVICE_OUT_BLUETOOTH_SCO |
                                 AUDIO_DEVICE_OUT_BLUETOOTH_SCO_HEADSET |
                                 AUDIO_DEVICE_OUT_BLUETOOTH_SCO_CARKIT |
                                 AUDIO_DEVICE_OUT_BLUETOOTH_A2DP |
                                 AUDIO_DEVICE_OUT_BLUETOOTH_A2DP_HEADPHONES |
                                 AUDIO_DEVICE_OUT_BLUETOOTH_A2DP_SPEAKER |
                                 AUDIO_DEVICE_OUT_HDMI |
                                 AUDIO_DEVICE_OUT_ANLG_DOCK_HEADSET |
                                 AUDIO_DEVICE_OUT_DGTL_DOCK_HEADSET |
                                 AUDIO_DEVICE_OUT_USB_ACCESSORY |
                                 AUDIO_DEVICE_OUT_USB_DEVICE |
                                 AUDIO_DEVICE_OUT_REMOTE_SUBMIX |
                                 AUDIO_DEVICE_OUT_TELEPHONY_TX |
                                 AUDIO_DEVICE_OUT_LINE |
                                 AUDIO_DEVICE_OUT_HDMI_ARC |
                                 AUDIO_DEVICE_OUT_SPDIF |
                                 AUDIO_DEVICE_OUT_FM |
                                 AUDIO_DEVICE_OUT_AUX_LINE |
                                 AUDIO_DEVICE_OUT_SPEAKER_SAFE |
                                 AUDIO_DEVICE_OUT_IP |
                                 AUDIO_DEVICE_OUT_BUS |
                                 AUDIO_DEVICE_OUT_PROXY |
                                 AUDIO_DEVICE_OUT_DEFAULT),
    AUDIO_DEVICE_OUT_ALL_A2DP = (AUDIO_DEVICE_OUT_BLUETOOTH_A2DP |
                                 AUDIO_DEVICE_OUT_BLUETOOTH_A2DP_HEADPHONES |
                                 AUDIO_DEVICE_OUT_BLUETOOTH_A2DP_SPEAKER),
    AUDIO_DEVICE_OUT_ALL_SCO  = (AUDIO_DEVICE_OUT_BLUETOOTH_SCO |
                                 AUDIO_DEVICE_OUT_BLUETOOTH_SCO_HEADSET |
                                 AUDIO_DEVICE_OUT_BLUETOOTH_SCO_CARKIT),
    AUDIO_DEVICE_OUT_ALL_USB  = (AUDIO_DEVICE_OUT_USB_ACCESSORY |
                                 AUDIO_DEVICE_OUT_USB_DEVICE),
    /* input devices */
    AUDIO_DEVICE_IN_COMMUNICATION         = AUDIO_DEVICE_BIT_IN | 0x1,
    AUDIO_DEVICE_IN_AMBIENT               = AUDIO_DEVICE_BIT_IN | 0x2,
    AUDIO_DEVICE_IN_BUILTIN_MIC           = AUDIO_DEVICE_BIT_IN | 0x4,
    AUDIO_DEVICE_IN_BLUETOOTH_SCO_HEADSET = AUDIO_DEVICE_BIT_IN | 0x8,
    AUDIO_DEVICE_IN_WIRED_HEADSET         = AUDIO_DEVICE_BIT_IN | 0x10,
    AUDIO_DEVICE_IN_AUX_DIGITAL           = AUDIO_DEVICE_BIT_IN | 0x20,
    AUDIO_DEVICE_IN_HDMI                  = AUDIO_DEVICE_IN_AUX_DIGITAL,
    /* Telephony voice RX path */
    AUDIO_DEVICE_IN_VOICE_CALL            = AUDIO_DEVICE_BIT_IN | 0x40,
    AUDIO_DEVICE_IN_TELEPHONY_RX          = AUDIO_DEVICE_IN_VOICE_CALL,
    AUDIO_DEVICE_IN_BACK_MIC              = AUDIO_DEVICE_BIT_IN | 0x80,
    AUDIO_DEVICE_IN_REMOTE_SUBMIX         = AUDIO_DEVICE_BIT_IN | 0x100,
    AUDIO_DEVICE_IN_ANLG_DOCK_HEADSET     = AUDIO_DEVICE_BIT_IN | 0x200,
    AUDIO_DEVICE_IN_DGTL_DOCK_HEADSET     = AUDIO_DEVICE_BIT_IN | 0x400,
    AUDIO_DEVICE_IN_USB_ACCESSORY         = AUDIO_DEVICE_BIT_IN | 0x800,
    AUDIO_DEVICE_IN_USB_DEVICE            = AUDIO_DEVICE_BIT_IN | 0x1000,
    /* FM tuner input */
    AUDIO_DEVICE_IN_FM_TUNER              = AUDIO_DEVICE_BIT_IN | 0x2000,
    /* TV tuner input */
    AUDIO_DEVICE_IN_TV_TUNER              = AUDIO_DEVICE_BIT_IN | 0x4000,
    /* Analog jack with line impedance detected */
    AUDIO_DEVICE_IN_LINE                  = AUDIO_DEVICE_BIT_IN | 0x8000,
    /* S/PDIF in */
    AUDIO_DEVICE_IN_SPDIF                 = AUDIO_DEVICE_BIT_IN | 0x10000,
    AUDIO_DEVICE_IN_BLUETOOTH_A2DP        = AUDIO_DEVICE_BIT_IN | 0x20000,
    AUDIO_DEVICE_IN_LOOPBACK              = AUDIO_DEVICE_BIT_IN | 0x40000,
    AUDIO_DEVICE_IN_IP                    = AUDIO_DEVICE_BIT_IN | 0x80000,
    /* audio bus implemented by the audio system (e.g an MOST stereo channel) */
    AUDIO_DEVICE_IN_BUS                   = AUDIO_DEVICE_BIT_IN | 0x100000,
    AUDIO_DEVICE_IN_PROXY                 = AUDIO_DEVICE_BIT_IN | 0x1000000,
    AUDIO_DEVICE_IN_DEFAULT               = AUDIO_DEVICE_BIT_IN | AUDIO_DEVICE_BIT_DEFAULT,

    AUDIO_DEVICE_IN_ALL     = (AUDIO_DEVICE_IN_COMMUNICATION |
                               AUDIO_DEVICE_IN_AMBIENT |
                               AUDIO_DEVICE_IN_BUILTIN_MIC |
                               AUDIO_DEVICE_IN_BLUETOOTH_SCO_HEADSET |
                               AUDIO_DEVICE_IN_WIRED_HEADSET |
                               AUDIO_DEVICE_IN_HDMI |
                               AUDIO_DEVICE_IN_TELEPHONY_RX |
                               AUDIO_DEVICE_IN_BACK_MIC |
                               AUDIO_DEVICE_IN_REMOTE_SUBMIX |
                               AUDIO_DEVICE_IN_ANLG_DOCK_HEADSET |
                               AUDIO_DEVICE_IN_DGTL_DOCK_HEADSET |
                               AUDIO_DEVICE_IN_USB_ACCESSORY |
                               AUDIO_DEVICE_IN_USB_DEVICE |
                               AUDIO_DEVICE_IN_FM_TUNER |
                               AUDIO_DEVICE_IN_TV_TUNER |
                               AUDIO_DEVICE_IN_LINE |
                               AUDIO_DEVICE_IN_SPDIF |
                               AUDIO_DEVICE_IN_BLUETOOTH_A2DP |
                               AUDIO_DEVICE_IN_LOOPBACK |
                               AUDIO_DEVICE_IN_IP |
                               AUDIO_DEVICE_IN_BUS |
                               AUDIO_DEVICE_IN_PROXY |
                               AUDIO_DEVICE_IN_DEFAULT),
    AUDIO_DEVICE_IN_ALL_SCO = AUDIO_DEVICE_IN_BLUETOOTH_SCO_HEADSET,
    AUDIO_DEVICE_IN_ALL_USB  = (AUDIO_DEVICE_IN_USB_ACCESSORY |
                                AUDIO_DEVICE_IN_USB_DEVICE),
};

typedef uint32_t audio_devices_t;

/* the audio output flags serve two purposes:
 * - when an AudioTrack is created they indicate a "wish" to be connected to an
 * output stream with attributes corresponding to the specified flags
 * - when present in an output profile descriptor listed for a particular audio
 * hardware module, they indicate that an output stream can be opened that
 * supports the attributes indicated by the flags.
 * the audio policy manager will try to match the flags in the request
 * (when getOuput() is called) to an available output stream.
 */
typedef enum {
    AUDIO_OUTPUT_FLAG_NONE = 0x0,       // no attributes
    AUDIO_OUTPUT_FLAG_DIRECT = 0x1,     // this output directly connects a track
                                        // to one output stream: no software mixer
    AUDIO_OUTPUT_FLAG_PRIMARY = 0x2,    // this output is the primary output of
                                        // the device. It is unique and must be
                                        // present. It is opened by default and
                                        // receives routing, audio mode and volume
                                        // controls related to voice calls.
    AUDIO_OUTPUT_FLAG_FAST = 0x4,       // output supports "fast tracks",
                                        // defined elsewhere
    AUDIO_OUTPUT_FLAG_DEEP_BUFFER = 0x8, // use deep audio buffers
    AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD = 0x10,  // offload playback of compressed
                                                // streams to hardware codec
    AUDIO_OUTPUT_FLAG_NON_BLOCKING = 0x20, // use non-blocking write
    AUDIO_OUTPUT_FLAG_HW_AV_SYNC = 0x40,   // output uses a hardware A/V synchronization source
    AUDIO_OUTPUT_FLAG_TTS = 0x80,          // output for streams transmitted through speaker
                                           // at a sample rate high enough to accommodate
                                           // lower-range ultrasonic playback
    AUDIO_OUTPUT_FLAG_RAW = 0x100,         // minimize signal processing
    AUDIO_OUTPUT_FLAG_SYNC = 0x200,        // synchronize I/O streams

    AUDIO_OUTPUT_FLAG_IEC958_NONAUDIO = 0x400, // Audio stream contains compressed audio in
                                               // SPDIF data bursts, not PCM.
    AUDIO_OUTPUT_FLAG_VOIP_RX = 0x800,  // use this flag in combination with DIRECT to
                                         // start voip over voice path.
    AUDIO_OUTPUT_FLAG_COMPRESS_PASSTHROUGH = 0x1000, // flag for HDMI compressed passthrough
    AUDIO_OUTPUT_FLAG_DIRECT_PCM = 0x2000, // flag for Direct PCM
} audio_output_flags_t;

/* The audio input flags are analogous to audio output flags.
 * Currently they are used only when an AudioRecord is created,
 * to indicate a preference to be connected to an input stream with
 * attributes corresponding to the specified flags.
 */
typedef enum {
    AUDIO_INPUT_FLAG_NONE       = 0x0,  // no attributes
    AUDIO_INPUT_FLAG_FAST       = 0x1,  // prefer an input that supports "fast tracks"
    AUDIO_INPUT_FLAG_HW_HOTWORD = 0x2,  // prefer an input that captures from hw hotword source
    AUDIO_INPUT_FLAG_RAW        = 0x4,  // minimize signal processing
    AUDIO_INPUT_FLAG_SYNC       = 0x8,  // synchronize I/O streams

} audio_input_flags_t;

/* Additional information about compressed streams offloaded to
 * hardware playback
 * The version and size fields must be initialized by the caller by using
 * one of the constants defined here.
 */
typedef struct {
    uint16_t version;                   // version of the info structure
    uint16_t size;                      // total size of the structure including version and size
    uint32_t sample_rate;               // sample rate in Hz
    audio_channel_mask_t channel_mask;  // channel mask
    audio_format_t format;              // audio format
    audio_stream_type_t stream_type;    // stream type
    uint32_t bit_rate;                  // bit rate in bits per second
    int64_t duration_us;                // duration in microseconds, -1 if unknown
    bool has_video;                     // true if stream is tied to a video stream
    bool is_streaming;                  // true if streaming, false if local playback
    uint32_t bit_width;
    uint32_t offload_buffer_size;       // offload fragment size
    audio_usage_t usage;
} audio_offload_info_t;

#define AUDIO_MAKE_OFFLOAD_INFO_VERSION(maj,min) \
            ((((maj) & 0xff) << 8) | ((min) & 0xff))

#define AUDIO_OFFLOAD_INFO_VERSION_0_1 AUDIO_MAKE_OFFLOAD_INFO_VERSION(0, 1)
#define AUDIO_OFFLOAD_INFO_VERSION_CURRENT AUDIO_OFFLOAD_INFO_VERSION_0_1

static const audio_offload_info_t AUDIO_INFO_INITIALIZER = {
    version: AUDIO_OFFLOAD_INFO_VERSION_CURRENT,
    size: sizeof(audio_offload_info_t),
    sample_rate: 0,
    channel_mask: 0,
    format: AUDIO_FORMAT_DEFAULT,
    stream_type: AUDIO_STREAM_VOICE_CALL,
    bit_rate: 0,
    duration_us: 0,
    has_video: false,
    is_streaming: false,
    bit_width: 16,
    offload_buffer_size: 0,
    usage: AUDIO_USAGE_UNKNOWN,
};

/* common audio stream configuration parameters
 * You should memset() the entire structure to zero before use to
 * ensure forward compatibility
 */
struct audio_config {
    uint32_t sample_rate;
    audio_channel_mask_t channel_mask;
    audio_format_t  format;
    audio_offload_info_t offload_info;
    size_t frame_count;
};
typedef struct audio_config audio_config_t;

static const audio_config_t AUDIO_CONFIG_INITIALIZER = {
    sample_rate: 0,
    channel_mask: AUDIO_CHANNEL_NONE,
    format: AUDIO_FORMAT_DEFAULT,
    offload_info: {
        version: AUDIO_OFFLOAD_INFO_VERSION_CURRENT,
        size: sizeof(audio_offload_info_t),
        sample_rate: 0,
        channel_mask: 0,
        format: AUDIO_FORMAT_DEFAULT,
        stream_type: AUDIO_STREAM_VOICE_CALL,
        bit_rate: 0,
        duration_us: 0,
        has_video: false,
        is_streaming: false
    },
    frame_count: 0,
};

struct audio_config_base {
    uint32_t sample_rate;
    audio_channel_mask_t channel_mask;
    audio_format_t  format;
};

typedef struct audio_config_base audio_config_base_t;

static const audio_config_base_t AUDIO_CONFIG_BASE_INITIALIZER = {
    sample_rate: 0,
    channel_mask: AUDIO_CHANNEL_NONE,
    format: AUDIO_FORMAT_DEFAULT
};

/* audio hw module handle functions or structures referencing a module */
typedef enum {
    AUDIO_MODULE_HANDLE_NONE = 0,
} audio_module_handle_t;

/******************************
 *  Volume control
 *****************************/

/* If the audio hardware supports gain control on some audio paths,
 * the platform can expose them in the audio_policy.conf file. The audio HAL
 * will then implement gain control functions that will use the following data
 * structures. */

/* Type of gain control exposed by an audio port */
#define AUDIO_GAIN_MODE_JOINT     0x1 /* supports joint channel gain control */
#define AUDIO_GAIN_MODE_CHANNELS  0x2 /* supports separate channel gain control */
#define AUDIO_GAIN_MODE_RAMP      0x4 /* supports gain ramps */

typedef uint32_t audio_gain_mode_t;


/* An audio_gain struct is a representation of a gain stage.
 * A gain stage is always attached to an audio port. */
struct audio_gain  {
    audio_gain_mode_t    mode;          /* e.g. AUDIO_GAIN_MODE_JOINT */
    audio_channel_mask_t channel_mask;  /* channels which gain an be controlled.
                                           N/A if AUDIO_GAIN_MODE_CHANNELS is not supported */
    int                  min_value;     /* minimum gain value in millibels */
    int                  max_value;     /* maximum gain value in millibels */
    int                  default_value; /* default gain value in millibels */
    unsigned int         step_value;    /* gain step in millibels */
    unsigned int         min_ramp_ms;   /* minimum ramp duration in ms */
    unsigned int         max_ramp_ms;   /* maximum ramp duration in ms */
};

/* The gain configuration structure is used to get or set the gain values of a
 * given port */
struct audio_gain_config  {
    int                  index;             /* index of the corresponding audio_gain in the
                                               audio_port gains[] table */
    audio_gain_mode_t    mode;              /* mode requested for this command */
    audio_channel_mask_t channel_mask;      /* channels which gain value follows.
                                               N/A in joint mode */

    // note this "8" is not FCC_8, so it won't need to be changed for > 8 channels
    int                  values[sizeof(audio_channel_mask_t) * 8]; /* gain values in millibels
                                               for each channel ordered from LSb to MSb in
                                               channel mask. The number of values is 1 in joint
                                               mode or popcount(channel_mask) */
    unsigned int         ramp_duration_ms; /* ramp duration in ms */
};

/******************************
 *  Routing control
 *****************************/

/* Types defined here are used to describe an audio source or sink at internal
 * framework interfaces (audio policy, patch panel) or at the audio HAL.
 * Sink and sources are grouped in a concept of “audio port” representing an
 * audio end point at the edge of the system managed by the module exposing
 * the interface. */

/* Audio port role: either source or sink */
typedef enum {
    AUDIO_PORT_ROLE_NONE,
    AUDIO_PORT_ROLE_SOURCE,
    AUDIO_PORT_ROLE_SINK,
} audio_port_role_t;

/* Audio port type indicates if it is a session (e.g AudioTrack),
 * a mix (e.g PlaybackThread output) or a physical device
 * (e.g AUDIO_DEVICE_OUT_SPEAKER) */
typedef enum {
    AUDIO_PORT_TYPE_NONE,
    AUDIO_PORT_TYPE_DEVICE,
    AUDIO_PORT_TYPE_MIX,
    AUDIO_PORT_TYPE_SESSION,
} audio_port_type_t;

/* Each port has a unique ID or handle allocated by policy manager */
typedef int audio_port_handle_t;
#define AUDIO_PORT_HANDLE_NONE 0

/* the maximum length for the human-readable device name */
#define AUDIO_PORT_MAX_NAME_LEN 128

/* maximum audio device address length */
#define AUDIO_DEVICE_MAX_ADDRESS_LEN 32

/* extension for audio port configuration structure when the audio port is a
 * hardware device */
struct audio_port_config_device_ext {
    audio_module_handle_t hw_module;                /* module the device is attached to */
    audio_devices_t       type;                     /* device type (e.g AUDIO_DEVICE_OUT_SPEAKER) */
    char                  address[AUDIO_DEVICE_MAX_ADDRESS_LEN]; /* device address. "" if N/A */
};

/* extension for audio port configuration structure when the audio port is a
 * sub mix */
struct audio_port_config_mix_ext {
    audio_module_handle_t hw_module;    /* module the stream is attached to */
    audio_io_handle_t handle;           /* I/O handle of the input/output stream */
    union {
        //TODO: change use case for output streams: use strategy and mixer attributes
        audio_stream_type_t stream;
        audio_source_t      source;
    } usecase;
};

/* extension for audio port configuration structure when the audio port is an
 * audio session */
struct audio_port_config_session_ext {
    audio_session_t   session; /* audio session */
};

/* Flags indicating which fields are to be considered in struct audio_port_config */
#define AUDIO_PORT_CONFIG_SAMPLE_RATE  0x1
#define AUDIO_PORT_CONFIG_CHANNEL_MASK 0x2
#define AUDIO_PORT_CONFIG_FORMAT       0x4
#define AUDIO_PORT_CONFIG_GAIN         0x8
#define AUDIO_PORT_CONFIG_ALL (AUDIO_PORT_CONFIG_SAMPLE_RATE | \
                               AUDIO_PORT_CONFIG_CHANNEL_MASK | \
                               AUDIO_PORT_CONFIG_FORMAT | \
                               AUDIO_PORT_CONFIG_GAIN)

/* audio port configuration structure used to specify a particular configuration of
 * an audio port */
struct audio_port_config {
    audio_port_handle_t      id;           /* port unique ID */
    audio_port_role_t        role;         /* sink or source */
    audio_port_type_t        type;         /* device, mix ... */
    unsigned int             config_mask;  /* e.g AUDIO_PORT_CONFIG_ALL */
    unsigned int             sample_rate;  /* sampling rate in Hz */
    audio_channel_mask_t     channel_mask; /* channel mask if applicable */
    audio_format_t           format;       /* format if applicable */
    struct audio_gain_config gain;         /* gain to apply if applicable */
    union {
        struct audio_port_config_device_ext  device;  /* device specific info */
        struct audio_port_config_mix_ext     mix;     /* mix specific info */
        struct audio_port_config_session_ext session; /* session specific info */
    } ext;
};


/* max number of sampling rates in audio port */
#define AUDIO_PORT_MAX_SAMPLING_RATES 16
/* max number of channel masks in audio port */
#define AUDIO_PORT_MAX_CHANNEL_MASKS 16
/* max number of audio formats in audio port */
#define AUDIO_PORT_MAX_FORMATS 16
/* max number of gain controls in audio port */
#define AUDIO_PORT_MAX_GAINS 16

/* extension for audio port structure when the audio port is a hardware device */
struct audio_port_device_ext {
    audio_module_handle_t hw_module;    /* module the device is attached to */
    audio_devices_t       type;         /* device type (e.g AUDIO_DEVICE_OUT_SPEAKER) */
    char                  address[AUDIO_DEVICE_MAX_ADDRESS_LEN];
};

/* Latency class of the audio mix */
typedef enum {
    AUDIO_LATENCY_LOW,
    AUDIO_LATENCY_NORMAL,
} audio_mix_latency_class_t;

/* extension for audio port structure when the audio port is a sub mix */
struct audio_port_mix_ext {
    audio_module_handle_t     hw_module;     /* module the stream is attached to */
    audio_io_handle_t         handle;        /* I/O handle of the input.output stream */
    audio_mix_latency_class_t latency_class; /* latency class */
    // other attributes: routing strategies
};

/* extension for audio port structure when the audio port is an audio session */
struct audio_port_session_ext {
    audio_session_t   session; /* audio session */
};

struct audio_port {
    audio_port_handle_t      id;                /* port unique ID */
    audio_port_role_t        role;              /* sink or source */
    audio_port_type_t        type;              /* device, mix ... */
    char                     name[AUDIO_PORT_MAX_NAME_LEN];
    unsigned int             num_sample_rates;  /* number of sampling rates in following array */
    unsigned int             sample_rates[AUDIO_PORT_MAX_SAMPLING_RATES];
    unsigned int             num_channel_masks; /* number of channel masks in following array */
    audio_channel_mask_t     channel_masks[AUDIO_PORT_MAX_CHANNEL_MASKS];
    unsigned int             num_formats;       /* number of formats in following array */
    audio_format_t           formats[AUDIO_PORT_MAX_FORMATS];
    unsigned int             num_gains;         /* number of gains in following array */
    struct audio_gain        gains[AUDIO_PORT_MAX_GAINS];
    struct audio_port_config active_config;     /* current audio port configuration */
    union {
        struct audio_port_device_ext  device;
        struct audio_port_mix_ext     mix;
        struct audio_port_session_ext session;
    } ext;
};

/* An audio patch represents a connection between one or more source ports and
 * one or more sink ports. Patches are connected and disconnected by audio policy manager or by
 * applications via framework APIs.
 * Each patch is identified by a handle at the interface used to create that patch. For instance,
 * when a patch is created by the audio HAL, the HAL allocates and returns a handle.
 * This handle is unique to a given audio HAL hardware module.
 * But the same patch receives another system wide unique handle allocated by the framework.
 * This unique handle is used for all transactions inside the framework.
 */
typedef enum {
    AUDIO_PATCH_HANDLE_NONE = 0,
} audio_patch_handle_t;

#define AUDIO_PATCH_PORTS_MAX   16

struct audio_patch {
    audio_patch_handle_t id;            /* patch unique ID */
    unsigned int      num_sources;      /* number of sources in following array */
    struct audio_port_config sources[AUDIO_PATCH_PORTS_MAX];
    unsigned int      num_sinks;        /* number of sinks in following array */
    struct audio_port_config sinks[AUDIO_PATCH_PORTS_MAX];
};



/* a HW synchronization source returned by the audio HAL */
typedef uint32_t audio_hw_sync_t;

/* an invalid HW synchronization source indicating an error */
#define AUDIO_HW_SYNC_INVALID 0

static inline bool audio_is_output_device(audio_devices_t device)
{
    if (((device & AUDIO_DEVICE_BIT_IN) == 0) &&
            (popcount(device) == 1) && ((device & ~AUDIO_DEVICE_OUT_ALL) == 0))
        return true;
    else
        return false;
}

static inline bool audio_is_input_device(audio_devices_t device)
{
    if ((device & AUDIO_DEVICE_BIT_IN) != 0) {
        device &= ~AUDIO_DEVICE_BIT_IN;
        if ((popcount(device) == 1) && ((device & ~AUDIO_DEVICE_IN_ALL) == 0))
            return true;
    }
    return false;
}

static inline bool audio_is_output_devices(audio_devices_t device)
{
    return (device & AUDIO_DEVICE_BIT_IN) == 0;
}

static inline bool audio_is_a2dp_in_device(audio_devices_t device)
{
    if ((device & AUDIO_DEVICE_BIT_IN) != 0) {
        device &= ~AUDIO_DEVICE_BIT_IN;
        if ((popcount(device) == 1) && (device & AUDIO_DEVICE_IN_BLUETOOTH_A2DP))
            return true;
    }
    return false;
}

static inline bool audio_is_a2dp_out_device(audio_devices_t device)
{
    if ((popcount(device) == 1) && (device & AUDIO_DEVICE_OUT_ALL_A2DP))
        return true;
    else
        return false;
}

// Deprecated - use audio_is_a2dp_out_device() instead
static inline bool audio_is_a2dp_device(audio_devices_t device)
{
    return audio_is_a2dp_out_device(device);
}

static inline bool audio_is_bluetooth_sco_device(audio_devices_t device)
{
    if ((device & AUDIO_DEVICE_BIT_IN) == 0) {
        if ((popcount(device) == 1) && ((device & ~AUDIO_DEVICE_OUT_ALL_SCO) == 0))
            return true;
    } else {
        device &= ~AUDIO_DEVICE_BIT_IN;
        if ((popcount(device) == 1) && ((device & ~AUDIO_DEVICE_IN_BLUETOOTH_SCO_HEADSET) == 0))
            return true;
    }

    return false;
}

static inline bool audio_is_usb_out_device(audio_devices_t device)
{
    return ((popcount(device) == 1) && (device & AUDIO_DEVICE_OUT_ALL_USB));
}

static inline bool audio_is_usb_in_device(audio_devices_t device)
{
    if ((device & AUDIO_DEVICE_BIT_IN) != 0) {
        device &= ~AUDIO_DEVICE_BIT_IN;
        if (popcount(device) == 1 && (device & AUDIO_DEVICE_IN_ALL_USB) != 0)
            return true;
    }
    return false;
}

/* OBSOLETE - use audio_is_usb_out_device() instead. */
static inline bool audio_is_usb_device(audio_devices_t device)
{
    return audio_is_usb_out_device(device);
}

static inline bool audio_is_remote_submix_device(audio_devices_t device)
{
    if ((audio_is_output_devices(device) &&
         (device & AUDIO_DEVICE_OUT_REMOTE_SUBMIX) == AUDIO_DEVICE_OUT_REMOTE_SUBMIX)
        || (!audio_is_output_devices(device) &&
         (device & AUDIO_DEVICE_IN_REMOTE_SUBMIX) == AUDIO_DEVICE_IN_REMOTE_SUBMIX))
        return true;
    else
        return false;
}

/* Returns true if:
 *  representation is valid, and
 *  there is at least one channel bit set which _could_ correspond to an input channel, and
 *  there are no channel bits set which could _not_ correspond to an input channel.
 * Otherwise returns false.
 */
static inline bool audio_is_input_channel(audio_channel_mask_t channel)
{
    uint32_t bits = audio_channel_mask_get_bits(channel);
    switch (audio_channel_mask_get_representation(channel)) {
    case AUDIO_CHANNEL_REPRESENTATION_POSITION:
        if (bits & ~AUDIO_CHANNEL_IN_ALL) {
            bits = 0;
        }
        // fall through
    case AUDIO_CHANNEL_REPRESENTATION_INDEX:
        return bits != 0;
    default:
        return false;
    }
}

/* Returns true if:
 *  representation is valid, and
 *  there is at least one channel bit set which _could_ correspond to an output channel, and
 *  there are no channel bits set which could _not_ correspond to an output channel.
 * Otherwise returns false.
 */
static inline bool audio_is_output_channel(audio_channel_mask_t channel)
{
    uint32_t bits = audio_channel_mask_get_bits(channel);
    switch (audio_channel_mask_get_representation(channel)) {
    case AUDIO_CHANNEL_REPRESENTATION_POSITION:
        if (bits & ~AUDIO_CHANNEL_OUT_ALL) {
            bits = 0;
        }
        // fall through
    case AUDIO_CHANNEL_REPRESENTATION_INDEX:
        return bits != 0;
    default:
        return false;
    }
}

/* Returns the number of channels from an input channel mask,
 * used in the context of audio input or recording.
 * If a channel bit is set which could _not_ correspond to an input channel,
 * it is excluded from the count.
 * Returns zero if the representation is invalid.
 */
static inline uint32_t audio_channel_count_from_in_mask(audio_channel_mask_t channel)
{
    uint32_t bits = audio_channel_mask_get_bits(channel);
    switch (audio_channel_mask_get_representation(channel)) {
    case AUDIO_CHANNEL_REPRESENTATION_POSITION:
        // TODO: We can now merge with from_out_mask and remove anding
        bits &= AUDIO_CHANNEL_IN_ALL;
        // fall through
    case AUDIO_CHANNEL_REPRESENTATION_INDEX:
        return popcount(bits);
    default:
        return 0;
    }
}

/* Returns the number of channels from an output channel mask,
 * used in the context of audio output or playback.
 * If a channel bit is set which could _not_ correspond to an output channel,
 * it is excluded from the count.
 * Returns zero if the representation is invalid.
 */
static inline uint32_t audio_channel_count_from_out_mask(audio_channel_mask_t channel)
{
    uint32_t bits = audio_channel_mask_get_bits(channel);
    switch (audio_channel_mask_get_representation(channel)) {
    case AUDIO_CHANNEL_REPRESENTATION_POSITION:
        // TODO: We can now merge with from_in_mask and remove anding
        bits &= AUDIO_CHANNEL_OUT_ALL;
        // fall through
    case AUDIO_CHANNEL_REPRESENTATION_INDEX:
        return popcount(bits);
    default:
        return 0;
    }
}

/* Derive a channel mask for index assignment from a channel count.
 * Returns the matching channel mask,
 * or AUDIO_CHANNEL_NONE if the channel count is zero,
 * or AUDIO_CHANNEL_INVALID if the channel count exceeds AUDIO_CHANNEL_COUNT_MAX.
 */
static inline audio_channel_mask_t audio_channel_mask_for_index_assignment_from_count(
        uint32_t channel_count)
{
    if (channel_count == 0) {
        return AUDIO_CHANNEL_NONE;
    }
    if (channel_count > AUDIO_CHANNEL_COUNT_MAX) {
        return AUDIO_CHANNEL_INVALID;
    }
    uint32_t bits = (1 << channel_count) - 1;
    return audio_channel_mask_from_representation_and_bits(
            AUDIO_CHANNEL_REPRESENTATION_INDEX, bits);
}

/* Derive an output channel mask for position assignment from a channel count.
 * This is to be used when the content channel mask is unknown. The 1, 2, 4, 5, 6, 7 and 8 channel
 * cases are mapped to the standard game/home-theater layouts, but note that 4 is mapped to quad,
 * and not stereo + FC + mono surround. A channel count of 3 is arbitrarily mapped to stereo + FC
 * for continuity with stereo.
 * Returns the matching channel mask,
 * or AUDIO_CHANNEL_NONE if the channel count is zero,
 * or AUDIO_CHANNEL_INVALID if the channel count exceeds that of the
 * configurations for which a default output channel mask is defined.
 */
static inline audio_channel_mask_t audio_channel_out_mask_from_count(uint32_t channel_count)
{
    uint32_t bits;
    switch (channel_count) {
    case 0:
        return AUDIO_CHANNEL_NONE;
    case 1:
        bits = AUDIO_CHANNEL_OUT_MONO;
        break;
    case 2:
        bits = AUDIO_CHANNEL_OUT_STEREO;
        break;
    case 3:
        bits = AUDIO_CHANNEL_OUT_STEREO | AUDIO_CHANNEL_OUT_FRONT_CENTER;
        break;
    case 4: // 4.0
        bits = AUDIO_CHANNEL_OUT_QUAD;
        break;
    case 5: // 5.0
        bits = AUDIO_CHANNEL_OUT_QUAD | AUDIO_CHANNEL_OUT_FRONT_CENTER;
        break;
    case 6: // 5.1
        bits = AUDIO_CHANNEL_OUT_5POINT1;
        break;
    case 7: // 6.1
        bits = AUDIO_CHANNEL_OUT_5POINT1 | AUDIO_CHANNEL_OUT_BACK_CENTER;
        break;
    case 8:
        bits = AUDIO_CHANNEL_OUT_7POINT1;
        break;
    // FIXME FCC_8
    default:
        return AUDIO_CHANNEL_INVALID;
    }
    return audio_channel_mask_from_representation_and_bits(
            AUDIO_CHANNEL_REPRESENTATION_POSITION, bits);
}

/* Derive a default input channel mask from a channel count.
 * Assumes a position mask for mono and stereo, or an index mask for channel counts > 2.
 * Returns the matching channel mask,
 * or AUDIO_CHANNEL_NONE if the channel count is zero,
 * or AUDIO_CHANNEL_INVALID if the channel count exceeds that of the
 * configurations for which a default input channel mask is defined.
 */
static inline audio_channel_mask_t audio_channel_in_mask_from_count(uint32_t channel_count)
{
    uint32_t bits;
    switch (channel_count) {
    case 0:
        return AUDIO_CHANNEL_NONE;
    case 1:
        bits = AUDIO_CHANNEL_IN_MONO;
        break;
    case 2:
        bits = AUDIO_CHANNEL_IN_STEREO;
        break;
    case 3:
    case 4:
    case 5:
    case 6:
    case 7:
    case 8:
        // FIXME FCC_8
        return audio_channel_mask_for_index_assignment_from_count(channel_count);
    default:
        return AUDIO_CHANNEL_INVALID;
    }
    return audio_channel_mask_from_representation_and_bits(
            AUDIO_CHANNEL_REPRESENTATION_POSITION, bits);
}

static inline bool audio_is_valid_format(audio_format_t format)
{
    switch (format & AUDIO_FORMAT_MAIN_MASK) {
    case AUDIO_FORMAT_PCM:
        switch (format) {
        case AUDIO_FORMAT_PCM_16_BIT:
        case AUDIO_FORMAT_PCM_8_BIT:
        case AUDIO_FORMAT_PCM_32_BIT:
        case AUDIO_FORMAT_PCM_8_24_BIT:
        case AUDIO_FORMAT_PCM_FLOAT:
        case AUDIO_FORMAT_PCM_24_BIT_PACKED:
            return true;
        default:
            return false;
        }
        /* not reached */
    case AUDIO_FORMAT_MP3:
    case AUDIO_FORMAT_AMR_NB:
    case AUDIO_FORMAT_AMR_WB:
    case AUDIO_FORMAT_AAC:
    case AUDIO_FORMAT_AAC_ADTS:
    case AUDIO_FORMAT_HE_AAC_V1:
    case AUDIO_FORMAT_HE_AAC_V2:
    case AUDIO_FORMAT_VORBIS:
    case AUDIO_FORMAT_OPUS:
    case AUDIO_FORMAT_AC3:
    case AUDIO_FORMAT_E_AC3:
    case AUDIO_FORMAT_DTS:
    case AUDIO_FORMAT_DTS_HD:
    case AUDIO_FORMAT_IEC61937:
    case AUDIO_FORMAT_QCELP:
    case AUDIO_FORMAT_EVRC:
    case AUDIO_FORMAT_EVRCB:
    case AUDIO_FORMAT_EVRCWB:
    case AUDIO_FORMAT_AAC_ADIF:
    case AUDIO_FORMAT_AMR_WB_PLUS:
    case AUDIO_FORMAT_MP2:
    case AUDIO_FORMAT_EVRCNW:
    case AUDIO_FORMAT_FLAC:
    case AUDIO_FORMAT_ALAC:
    case AUDIO_FORMAT_APE:
    case AUDIO_FORMAT_WMA:
    case AUDIO_FORMAT_WMA_PRO:
    case AUDIO_FORMAT_DSD:
        return true;
    case AUDIO_FORMAT_PCM_OFFLOAD:
        if (format != AUDIO_FORMAT_PCM_16_BIT_OFFLOAD &&
                format != AUDIO_FORMAT_PCM_24_BIT_OFFLOAD) {
            return false;
        }
        return true;
    default:
        return false;
    }
}

/**
 * Extract the primary format, eg. PCM, AC3, etc.
 */
static inline audio_format_t audio_get_main_format(audio_format_t format)
{
    return (audio_format_t)(format & AUDIO_FORMAT_MAIN_MASK);
}

/**
 * Is the data plain PCM samples that can be scaled and mixed?
 */
static inline bool audio_is_linear_pcm(audio_format_t format)
{
    return (audio_get_main_format(format) == AUDIO_FORMAT_PCM);
}

/**
 * For this format, is the number of PCM audio frames directly proportional
 * to the number of data bytes?
 *
 * In other words, is the format transported as PCM audio samples,
 * but not necessarily scalable or mixable.
 * This returns true for real PCM, but also for AUDIO_FORMAT_IEC61937,
 * which is transported as 16 bit PCM audio, but where the encoded data
 * cannot be mixed or scaled.
 */
static inline bool audio_has_proportional_frames(audio_format_t format)
{
    audio_format_t mainFormat = audio_get_main_format(format);
    return (mainFormat == AUDIO_FORMAT_PCM
            || mainFormat == AUDIO_FORMAT_IEC61937);
}

static inline size_t audio_bytes_per_sample(audio_format_t format)
{
    size_t size = 0;

    switch (format) {
    case AUDIO_FORMAT_PCM_32_BIT:
    case AUDIO_FORMAT_PCM_8_24_BIT:
    case AUDIO_FORMAT_PCM_24_BIT_OFFLOAD:
        size = sizeof(int32_t);
        break;
    case AUDIO_FORMAT_PCM_24_BIT_PACKED:
        size = sizeof(uint8_t) * 3;
        break;
    case AUDIO_FORMAT_PCM_16_BIT:
    case AUDIO_FORMAT_IEC61937:
    case AUDIO_FORMAT_PCM_16_BIT_OFFLOAD:
        size = sizeof(int16_t);
        break;
    case AUDIO_FORMAT_PCM_8_BIT:
        size = sizeof(uint8_t);
        break;
    case AUDIO_FORMAT_PCM_FLOAT:
        size = sizeof(float);
        break;
    default:
        break;
    }
    return size;
}

/* converts device address to string sent to audio HAL via set_parameters */
static inline char *audio_device_address_to_parameter(audio_devices_t device, const char *address)
{
    const size_t kSize = AUDIO_DEVICE_MAX_ADDRESS_LEN + sizeof("a2dp_sink_address=");
    char param[kSize];

    if (device & AUDIO_DEVICE_OUT_ALL_A2DP)
        snprintf(param, kSize, "%s=%s", "a2dp_sink_address", address);
    else if (device & AUDIO_DEVICE_OUT_REMOTE_SUBMIX)
        snprintf(param, kSize, "%s=%s", "mix", address);
    else
        snprintf(param, kSize, "%s", address);

    return strdup(param);
}

static inline bool audio_device_is_digital(audio_devices_t device) {
    if ((device & AUDIO_DEVICE_BIT_IN) != 0) {
        // input
        return (~AUDIO_DEVICE_BIT_IN & device & (AUDIO_DEVICE_IN_ALL_USB |
                          AUDIO_DEVICE_IN_HDMI |
                          AUDIO_DEVICE_IN_SPDIF |
                          AUDIO_DEVICE_IN_IP |
                          AUDIO_DEVICE_IN_BUS)) != 0;
    } else {
        // output
        return (device & (AUDIO_DEVICE_OUT_ALL_USB |
                          AUDIO_DEVICE_OUT_HDMI |
                          AUDIO_DEVICE_OUT_HDMI_ARC |
                          AUDIO_DEVICE_OUT_SPDIF |
                          AUDIO_DEVICE_OUT_IP |
                          AUDIO_DEVICE_OUT_BUS)) != 0;
    }
}

__END_DECLS

#endif  // ANDROID_AUDIO_CORE_H