summaryrefslogtreecommitdiffstats
path: root/media/libmedia/AudioSystem.cpp
blob: 9cae21c68ce249984a330be557799da686393bf3 (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
/*
 * Copyright (C) 2006-2007 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.
 */

#define LOG_TAG "AudioSystem"
//#define LOG_NDEBUG 0

#include <utils/Log.h>
#include <binder/IServiceManager.h>
#include <media/AudioSystem.h>
#include <media/IAudioFlinger.h>
#include <media/IAudioPolicyService.h>
#include <math.h>

#include <system/audio.h>

// ----------------------------------------------------------------------------

namespace android {

// client singleton for AudioFlinger binder interface
Mutex AudioSystem::gLock;
Mutex AudioSystem::gLockCache;
Mutex AudioSystem::gLockAPS;
Mutex AudioSystem::gLockAPC;
sp<IAudioFlinger> AudioSystem::gAudioFlinger;
sp<AudioSystem::AudioFlingerClient> AudioSystem::gAudioFlingerClient;
audio_error_callback AudioSystem::gAudioErrorCallback = NULL;

// Cached values for output handles
DefaultKeyedVector<audio_io_handle_t, AudioSystem::OutputDescriptor *> AudioSystem::gOutputs(NULL);

// Cached values for recording queries, all protected by gLock
uint32_t AudioSystem::gPrevInSamplingRate;
audio_format_t AudioSystem::gPrevInFormat;
audio_channel_mask_t AudioSystem::gPrevInChannelMask;
size_t AudioSystem::gInBuffSize = 0;    // zero indicates cache is invalid

sp<AudioSystem::AudioPortCallback> AudioSystem::gAudioPortCallback;

// establish binder interface to AudioFlinger service
const sp<IAudioFlinger> AudioSystem::get_audio_flinger()
{
    sp<IAudioFlinger> af;
    sp<AudioFlingerClient> afc;
    {
        Mutex::Autolock _l(gLock);
        if (gAudioFlinger == 0) {
            sp<IServiceManager> sm = defaultServiceManager();
            sp<IBinder> binder;
            do {
                binder = sm->getService(String16("media.audio_flinger"));
                if (binder != 0)
                    break;
                ALOGW("AudioFlinger not published, waiting...");
                usleep(500000); // 0.5 s
            } while (true);
            if (gAudioFlingerClient == NULL) {
                gAudioFlingerClient = new AudioFlingerClient();
            } else {
                if (gAudioErrorCallback) {
                    gAudioErrorCallback(NO_ERROR);
                }
            }
            binder->linkToDeath(gAudioFlingerClient);
            gAudioFlinger = interface_cast<IAudioFlinger>(binder);
            LOG_ALWAYS_FATAL_IF(gAudioFlinger == 0);
            afc = gAudioFlingerClient;
        }
        af = gAudioFlinger;
    }
    if (afc != 0) {
        af->registerClient(afc);
    }
    return af;
}

/* static */ status_t AudioSystem::checkAudioFlinger()
{
    if (defaultServiceManager()->checkService(String16("media.audio_flinger")) != 0) {
        return NO_ERROR;
    }
    return DEAD_OBJECT;
}

status_t AudioSystem::muteMicrophone(bool state)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    return af->setMicMute(state);
}

status_t AudioSystem::isMicrophoneMuted(bool* state)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    *state = af->getMicMute();
    return NO_ERROR;
}

status_t AudioSystem::setMasterVolume(float value)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    af->setMasterVolume(value);
    return NO_ERROR;
}

status_t AudioSystem::setMasterMute(bool mute)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    af->setMasterMute(mute);
    return NO_ERROR;
}

status_t AudioSystem::getMasterVolume(float* volume)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    *volume = af->masterVolume();
    return NO_ERROR;
}

status_t AudioSystem::getMasterMute(bool* mute)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    *mute = af->masterMute();
    return NO_ERROR;
}

status_t AudioSystem::setStreamVolume(audio_stream_type_t stream, float value,
        audio_io_handle_t output)
{
    if (uint32_t(stream) >= AUDIO_STREAM_CNT) return BAD_VALUE;
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    af->setStreamVolume(stream, value, output);
    return NO_ERROR;
}

status_t AudioSystem::setStreamMute(audio_stream_type_t stream, bool mute)
{
    if (uint32_t(stream) >= AUDIO_STREAM_CNT) return BAD_VALUE;
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    af->setStreamMute(stream, mute);
    return NO_ERROR;
}

status_t AudioSystem::getStreamVolume(audio_stream_type_t stream, float* volume,
        audio_io_handle_t output)
{
    if (uint32_t(stream) >= AUDIO_STREAM_CNT) return BAD_VALUE;
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    *volume = af->streamVolume(stream, output);
    return NO_ERROR;
}

status_t AudioSystem::getStreamMute(audio_stream_type_t stream, bool* mute)
{
    if (uint32_t(stream) >= AUDIO_STREAM_CNT) return BAD_VALUE;
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    *mute = af->streamMute(stream);
    return NO_ERROR;
}

status_t AudioSystem::setMode(audio_mode_t mode)
{
    if (uint32_t(mode) >= AUDIO_MODE_CNT) return BAD_VALUE;
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    return af->setMode(mode);
}

status_t AudioSystem::setParameters(audio_io_handle_t ioHandle, const String8& keyValuePairs)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    return af->setParameters(ioHandle, keyValuePairs);
}

String8 AudioSystem::getParameters(audio_io_handle_t ioHandle, const String8& keys)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    String8 result = String8("");
    if (af == 0) return result;

    result = af->getParameters(ioHandle, keys);
    return result;
}

status_t AudioSystem::setParameters(const String8& keyValuePairs)
{
    return setParameters(AUDIO_IO_HANDLE_NONE, keyValuePairs);
}

String8 AudioSystem::getParameters(const String8& keys)
{
    return getParameters(AUDIO_IO_HANDLE_NONE, keys);
}

// convert volume steps to natural log scale

// change this value to change volume scaling
static const float dBPerStep = 0.5f;
// shouldn't need to touch these
static const float dBConvert = -dBPerStep * 2.302585093f / 20.0f;
static const float dBConvertInverse = 1.0f / dBConvert;

float AudioSystem::linearToLog(int volume)
{
    // float v = volume ? exp(float(100 - volume) * dBConvert) : 0;
    // ALOGD("linearToLog(%d)=%f", volume, v);
    // return v;
    return volume ? exp(float(100 - volume) * dBConvert) : 0;
}

int AudioSystem::logToLinear(float volume)
{
    // int v = volume ? 100 - int(dBConvertInverse * log(volume) + 0.5) : 0;
    // ALOGD("logTolinear(%d)=%f", v, volume);
    // return v;
    return volume ? 100 - int(dBConvertInverse * log(volume) + 0.5) : 0;
}

status_t AudioSystem::getOutputSamplingRate(uint32_t* samplingRate, audio_stream_type_t streamType)
{
    audio_io_handle_t output;

    if (streamType == AUDIO_STREAM_DEFAULT) {
        streamType = AUDIO_STREAM_MUSIC;
    }

    output = getOutput(streamType);
    if (output == 0) {
        return PERMISSION_DENIED;
    }

    return getSamplingRate(output, samplingRate);
}

status_t AudioSystem::getSamplingRate(audio_io_handle_t output,
                                      uint32_t* samplingRate)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;

    Mutex::Autolock _l(gLockCache);

    OutputDescriptor *outputDesc = AudioSystem::gOutputs.valueFor(output);
    if (outputDesc == NULL) {
        ALOGV("getOutputSamplingRate() no output descriptor for output %d in gOutputs", output);
        gLockCache.unlock();
        *samplingRate = af->sampleRate(output);
        gLockCache.lock();
    } else {
        ALOGV("getOutputSamplingRate() reading from output desc");
        *samplingRate = outputDesc->samplingRate;
    }
    if (*samplingRate == 0) {
        ALOGE("AudioSystem::getSamplingRate failed for output %d", output);
        return BAD_VALUE;
    }

    ALOGV("getSamplingRate() output %d, sampling rate %u", output, *samplingRate);

    return NO_ERROR;
}

status_t AudioSystem::getOutputFrameCount(size_t* frameCount, audio_stream_type_t streamType)
{
    audio_io_handle_t output;

    if (streamType == AUDIO_STREAM_DEFAULT) {
        streamType = AUDIO_STREAM_MUSIC;
    }

    output = getOutput(streamType);
    if (output == AUDIO_IO_HANDLE_NONE) {
        return PERMISSION_DENIED;
    }

    return getFrameCount(output, frameCount);
}

status_t AudioSystem::getFrameCount(audio_io_handle_t output,
                                    size_t* frameCount)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;

    Mutex::Autolock _l(gLockCache);

    OutputDescriptor *outputDesc = AudioSystem::gOutputs.valueFor(output);
    if (outputDesc == NULL) {
        gLockCache.unlock();
        *frameCount = af->frameCount(output);
        gLockCache.lock();
    } else {
        *frameCount = outputDesc->frameCount;
    }
    if (*frameCount == 0) {
        ALOGE("AudioSystem::getFrameCount failed for output %d", output);
        return BAD_VALUE;
    }

    ALOGV("getFrameCount() output %d, frameCount %zu", output, *frameCount);

    return NO_ERROR;
}

status_t AudioSystem::getOutputLatency(uint32_t* latency, audio_stream_type_t streamType)
{
    audio_io_handle_t output;

    if (streamType == AUDIO_STREAM_DEFAULT) {
        streamType = AUDIO_STREAM_MUSIC;
    }

    output = getOutput(streamType);
    if (output == AUDIO_IO_HANDLE_NONE) {
        return PERMISSION_DENIED;
    }

    return getLatency(output, latency);
}

status_t AudioSystem::getLatency(audio_io_handle_t output,
                                 uint32_t* latency)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;

    Mutex::Autolock _l(gLockCache);

    OutputDescriptor *outputDesc = AudioSystem::gOutputs.valueFor(output);
    if (outputDesc == NULL) {
        gLockCache.unlock();
        *latency = af->latency(output);
        gLockCache.lock();
    } else {
        *latency = outputDesc->latency;
    }

    ALOGV("getLatency() output %d, latency %d", output, *latency);

    return NO_ERROR;
}

status_t AudioSystem::getInputBufferSize(uint32_t sampleRate, audio_format_t format,
        audio_channel_mask_t channelMask, size_t* buffSize)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) {
        return PERMISSION_DENIED;
    }
    Mutex::Autolock _l(gLockCache);
    // Do we have a stale gInBufferSize or are we requesting the input buffer size for new values
    size_t inBuffSize = gInBuffSize;
    if ((inBuffSize == 0) || (sampleRate != gPrevInSamplingRate) || (format != gPrevInFormat)
        || (channelMask != gPrevInChannelMask)) {
        gLockCache.unlock();
        inBuffSize = af->getInputBufferSize(sampleRate, format, channelMask);
        gLockCache.lock();
        if (inBuffSize == 0) {
            ALOGE("AudioSystem::getInputBufferSize failed sampleRate %d format %#x channelMask %x",
                    sampleRate, format, channelMask);
            return BAD_VALUE;
        }
        // A benign race is possible here: we could overwrite a fresher cache entry
        // save the request params
        gPrevInSamplingRate = sampleRate;
        gPrevInFormat = format;
        gPrevInChannelMask = channelMask;

        gInBuffSize = inBuffSize;
    }
    *buffSize = inBuffSize;

    return NO_ERROR;
}

status_t AudioSystem::setVoiceVolume(float value)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    return af->setVoiceVolume(value);
}

status_t AudioSystem::getRenderPosition(audio_io_handle_t output, uint32_t *halFrames,
                                        uint32_t *dspFrames)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;

    return af->getRenderPosition(halFrames, dspFrames, output);
}

uint32_t AudioSystem::getInputFramesLost(audio_io_handle_t ioHandle)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    uint32_t result = 0;
    if (af == 0) return result;
    if (ioHandle == AUDIO_IO_HANDLE_NONE) return result;

    result = af->getInputFramesLost(ioHandle);
    return result;
}

audio_unique_id_t AudioSystem::newAudioUniqueId()
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return AUDIO_UNIQUE_ID_ALLOCATE;
    return af->newAudioUniqueId();
}

void AudioSystem::acquireAudioSessionId(int audioSession, pid_t pid)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af != 0) {
        af->acquireAudioSessionId(audioSession, pid);
    }
}

void AudioSystem::releaseAudioSessionId(int audioSession, pid_t pid)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af != 0) {
        af->releaseAudioSessionId(audioSession, pid);
    }
}

audio_hw_sync_t AudioSystem::getAudioHwSyncForSession(audio_session_t sessionId)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return AUDIO_HW_SYNC_INVALID;
    return af->getAudioHwSyncForSession(sessionId);
}

// ---------------------------------------------------------------------------

void AudioSystem::AudioFlingerClient::binderDied(const wp<IBinder>& who __unused)
{
    audio_error_callback cb = NULL;
    {
        Mutex::Autolock _l(AudioSystem::gLock);
        AudioSystem::gAudioFlinger.clear();
        cb = gAudioErrorCallback;
    }

    {
        // clear output handles and stream to output map caches
        Mutex::Autolock _l(gLockCache);
        AudioSystem::gOutputs.clear();
    }

    if (cb) {
        cb(DEAD_OBJECT);
    }
    ALOGW("AudioFlinger server died!");
}

void AudioSystem::AudioFlingerClient::ioConfigChanged(int event, audio_io_handle_t ioHandle,
        const void *param2) {
    ALOGV("ioConfigChanged() event %d", event);
    const OutputDescriptor *desc;
    audio_stream_type_t stream;

    if (ioHandle == AUDIO_IO_HANDLE_NONE) return;

    Mutex::Autolock _l(AudioSystem::gLockCache);

    switch (event) {
    case STREAM_CONFIG_CHANGED:
        break;
    case OUTPUT_OPENED: {
        if (gOutputs.indexOfKey(ioHandle) >= 0) {
            ALOGV("ioConfigChanged() opening already existing output! %d", ioHandle);
            break;
        }
        if (param2 == NULL) break;
        desc = (const OutputDescriptor *)param2;

        OutputDescriptor *outputDesc =  new OutputDescriptor(*desc);
        gOutputs.add(ioHandle, outputDesc);
        ALOGV("ioConfigChanged() new output samplingRate %u, format %#x channel mask %#x frameCount %zu "
                "latency %d",
                outputDesc->samplingRate, outputDesc->format, outputDesc->channelMask,
                outputDesc->frameCount, outputDesc->latency);
        } break;
    case OUTPUT_CLOSED: {
        if (gOutputs.indexOfKey(ioHandle) < 0) {
            ALOGW("ioConfigChanged() closing unknown output! %d", ioHandle);
            break;
        }
        ALOGV("ioConfigChanged() output %d closed", ioHandle);

        gOutputs.removeItem(ioHandle);
        } break;

    case OUTPUT_CONFIG_CHANGED: {
        int index = gOutputs.indexOfKey(ioHandle);
        if (index < 0) {
            ALOGW("ioConfigChanged() modifying unknown output! %d", ioHandle);
            break;
        }
        if (param2 == NULL) break;
        desc = (const OutputDescriptor *)param2;

        ALOGV("ioConfigChanged() new config for output %d samplingRate %u, format %#x channel mask %#x "
                "frameCount %zu latency %d",
                ioHandle, desc->samplingRate, desc->format,
                desc->channelMask, desc->frameCount, desc->latency);
        OutputDescriptor *outputDesc = gOutputs.valueAt(index);
        delete outputDesc;
        outputDesc =  new OutputDescriptor(*desc);
        gOutputs.replaceValueFor(ioHandle, outputDesc);
    } break;
    case INPUT_OPENED:
    case INPUT_CLOSED:
    case INPUT_CONFIG_CHANGED:
        break;

    }
}

void AudioSystem::setErrorCallback(audio_error_callback cb)
{
    Mutex::Autolock _l(gLock);
    gAudioErrorCallback = cb;
}

// client singleton for AudioPolicyService binder interface
// protected by gLockAPS
sp<IAudioPolicyService> AudioSystem::gAudioPolicyService;
sp<AudioSystem::AudioPolicyServiceClient> AudioSystem::gAudioPolicyServiceClient;


// establish binder interface to AudioPolicy service
const sp<IAudioPolicyService> AudioSystem::get_audio_policy_service()
{
    sp<IAudioPolicyService> ap;
    sp<AudioPolicyServiceClient> apc;
    {
        Mutex::Autolock _l(gLockAPS);
        if (gAudioPolicyService == 0) {
            sp<IServiceManager> sm = defaultServiceManager();
            sp<IBinder> binder;
            do {
                binder = sm->getService(String16("media.audio_policy"));
                if (binder != 0)
                    break;
                ALOGW("AudioPolicyService not published, waiting...");
                usleep(500000); // 0.5 s
            } while (true);
            if (gAudioPolicyServiceClient == NULL) {
                gAudioPolicyServiceClient = new AudioPolicyServiceClient();
            }
            binder->linkToDeath(gAudioPolicyServiceClient);
            gAudioPolicyService = interface_cast<IAudioPolicyService>(binder);
            LOG_ALWAYS_FATAL_IF(gAudioPolicyService == 0);
            apc = gAudioPolicyServiceClient;
        }
        ap = gAudioPolicyService;
    }
    if (apc != 0) {
        ap->registerClient(apc);
    }

    return ap;
}

// ---------------------------------------------------------------------------

status_t AudioSystem::setDeviceConnectionState(audio_devices_t device,
                                               audio_policy_dev_state_t state,
                                               const char *device_address)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    const char *address = "";

    if (aps == 0) return PERMISSION_DENIED;

    if (device_address != NULL) {
        address = device_address;
    }

    return aps->setDeviceConnectionState(device, state, address);
}

audio_policy_dev_state_t AudioSystem::getDeviceConnectionState(audio_devices_t device,
                                                  const char *device_address)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return AUDIO_POLICY_DEVICE_STATE_UNAVAILABLE;

    return aps->getDeviceConnectionState(device, device_address);
}

status_t AudioSystem::setPhoneState(audio_mode_t state)
{
    if (uint32_t(state) >= AUDIO_MODE_CNT) return BAD_VALUE;
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;

    return aps->setPhoneState(state);
}

status_t AudioSystem::setForceUse(audio_policy_force_use_t usage, audio_policy_forced_cfg_t config)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->setForceUse(usage, config);
}

audio_policy_forced_cfg_t AudioSystem::getForceUse(audio_policy_force_use_t usage)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return AUDIO_POLICY_FORCE_NONE;
    return aps->getForceUse(usage);
}


audio_io_handle_t AudioSystem::getOutput(audio_stream_type_t stream,
                                    uint32_t samplingRate,
                                    audio_format_t format,
                                    audio_channel_mask_t channelMask,
                                    audio_output_flags_t flags,
                                    const audio_offload_info_t *offloadInfo)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return 0;
    return aps->getOutput(stream, samplingRate, format, channelMask, flags, offloadInfo);
}

status_t AudioSystem::getOutputForAttr(const audio_attributes_t *attr,
                                        audio_io_handle_t *output,
                                        audio_session_t session,
                                        audio_stream_type_t *stream,
                                        uint32_t samplingRate,
                                        audio_format_t format,
                                        audio_channel_mask_t channelMask,
                                        audio_output_flags_t flags,
                                        const audio_offload_info_t *offloadInfo)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return NO_INIT;
    return aps->getOutputForAttr(attr, output, session, stream,
                                 samplingRate, format, channelMask,
                                 flags, offloadInfo);
}

status_t AudioSystem::startOutput(audio_io_handle_t output,
                                  audio_stream_type_t stream,
                                  audio_session_t session)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->startOutput(output, stream, session);
}

status_t AudioSystem::stopOutput(audio_io_handle_t output,
                                 audio_stream_type_t stream,
                                 audio_session_t session)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->stopOutput(output, stream, session);
}

void AudioSystem::releaseOutput(audio_io_handle_t output,
                                audio_stream_type_t stream,
                                audio_session_t session)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return;
    aps->releaseOutput(output, stream, session);
}

status_t AudioSystem::getInputForAttr(const audio_attributes_t *attr,
                                audio_io_handle_t *input,
                                audio_session_t session,
                                uint32_t samplingRate,
                                audio_format_t format,
                                audio_channel_mask_t channelMask,
                                audio_input_flags_t flags)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return NO_INIT;
    return aps->getInputForAttr(attr, input, session, samplingRate, format, channelMask, flags);
}

status_t AudioSystem::startInput(audio_io_handle_t input,
                                 audio_session_t session)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->startInput(input, session);
}

status_t AudioSystem::stopInput(audio_io_handle_t input,
                                audio_session_t session)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->stopInput(input, session);
}

void AudioSystem::releaseInput(audio_io_handle_t input,
                               audio_session_t session)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return;
    aps->releaseInput(input, session);
}

status_t AudioSystem::initStreamVolume(audio_stream_type_t stream,
                                    int indexMin,
                                    int indexMax)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->initStreamVolume(stream, indexMin, indexMax);
}

status_t AudioSystem::setStreamVolumeIndex(audio_stream_type_t stream,
                                           int index,
                                           audio_devices_t device)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->setStreamVolumeIndex(stream, index, device);
}

status_t AudioSystem::getStreamVolumeIndex(audio_stream_type_t stream,
                                           int *index,
                                           audio_devices_t device)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->getStreamVolumeIndex(stream, index, device);
}

uint32_t AudioSystem::getStrategyForStream(audio_stream_type_t stream)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return 0;
    return aps->getStrategyForStream(stream);
}

audio_devices_t AudioSystem::getDevicesForStream(audio_stream_type_t stream)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return AUDIO_DEVICE_NONE;
    return aps->getDevicesForStream(stream);
}

audio_io_handle_t AudioSystem::getOutputForEffect(const effect_descriptor_t *desc)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    // FIXME change return type to status_t, and return PERMISSION_DENIED here
    if (aps == 0) return AUDIO_IO_HANDLE_NONE;
    return aps->getOutputForEffect(desc);
}

status_t AudioSystem::registerEffect(const effect_descriptor_t *desc,
                                audio_io_handle_t io,
                                uint32_t strategy,
                                int session,
                                int id)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->registerEffect(desc, io, strategy, session, id);
}

status_t AudioSystem::unregisterEffect(int id)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->unregisterEffect(id);
}

status_t AudioSystem::setEffectEnabled(int id, bool enabled)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->setEffectEnabled(id, enabled);
}

status_t AudioSystem::isStreamActive(audio_stream_type_t stream, bool* state, uint32_t inPastMs)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    if (state == NULL) return BAD_VALUE;
    *state = aps->isStreamActive(stream, inPastMs);
    return NO_ERROR;
}

status_t AudioSystem::isStreamActiveRemotely(audio_stream_type_t stream, bool* state,
        uint32_t inPastMs)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    if (state == NULL) return BAD_VALUE;
    *state = aps->isStreamActiveRemotely(stream, inPastMs);
    return NO_ERROR;
}

status_t AudioSystem::isSourceActive(audio_source_t stream, bool* state)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    if (state == NULL) return BAD_VALUE;
    *state = aps->isSourceActive(stream);
    return NO_ERROR;
}

uint32_t AudioSystem::getPrimaryOutputSamplingRate()
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return 0;
    return af->getPrimaryOutputSamplingRate();
}

size_t AudioSystem::getPrimaryOutputFrameCount()
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return 0;
    return af->getPrimaryOutputFrameCount();
}

status_t AudioSystem::setLowRamDevice(bool isLowRamDevice)
{
    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
    if (af == 0) return PERMISSION_DENIED;
    return af->setLowRamDevice(isLowRamDevice);
}

void AudioSystem::clearAudioConfigCache()
{
    // called by restoreTrack_l(), which needs new IAudioFlinger and IAudioPolicyService instances
    ALOGV("clearAudioConfigCache()");
    {
        Mutex::Autolock _l(gLockCache);
        gOutputs.clear();
    }
    {
        Mutex::Autolock _l(gLock);
        gAudioFlinger.clear();
    }
    {
        Mutex::Autolock _l(gLockAPS);
        gAudioPolicyService.clear();
    }
    // Do not clear gAudioPortCallback
}

bool AudioSystem::isOffloadSupported(const audio_offload_info_t& info)
{
    ALOGV("isOffloadSupported()");
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return false;
    return aps->isOffloadSupported(info);
}

status_t AudioSystem::listAudioPorts(audio_port_role_t role,
                                     audio_port_type_t type,
                                     unsigned int *num_ports,
                                     struct audio_port *ports,
                                     unsigned int *generation)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->listAudioPorts(role, type, num_ports, ports, generation);
}

status_t AudioSystem::getAudioPort(struct audio_port *port)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->getAudioPort(port);
}

status_t AudioSystem::createAudioPatch(const struct audio_patch *patch,
                                   audio_patch_handle_t *handle)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->createAudioPatch(patch, handle);
}

status_t AudioSystem::releaseAudioPatch(audio_patch_handle_t handle)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->releaseAudioPatch(handle);
}

status_t AudioSystem::listAudioPatches(unsigned int *num_patches,
                                  struct audio_patch *patches,
                                  unsigned int *generation)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->listAudioPatches(num_patches, patches, generation);
}

status_t AudioSystem::setAudioPortConfig(const struct audio_port_config *config)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->setAudioPortConfig(config);
}

void AudioSystem::setAudioPortCallback(sp<AudioPortCallback> callBack)
{
    Mutex::Autolock _l(gLockAPC);
    gAudioPortCallback = callBack;
}

status_t AudioSystem::acquireSoundTriggerSession(audio_session_t *session,
                                       audio_io_handle_t *ioHandle,
                                       audio_devices_t *device)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->acquireSoundTriggerSession(session, ioHandle, device);
}

status_t AudioSystem::releaseSoundTriggerSession(audio_session_t session)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->releaseSoundTriggerSession(session);
}

audio_mode_t AudioSystem::getPhoneState()
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return AUDIO_MODE_INVALID;
    return aps->getPhoneState();
}

status_t AudioSystem::registerPolicyMixes(Vector<AudioMix> mixes, bool registration)
{
    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
    if (aps == 0) return PERMISSION_DENIED;
    return aps->registerPolicyMixes(mixes, registration);
}

// ---------------------------------------------------------------------------

void AudioSystem::AudioPolicyServiceClient::binderDied(const wp<IBinder>& who __unused)
{
    {
        Mutex::Autolock _l(gLockAPC);
        if (gAudioPortCallback != 0) {
            gAudioPortCallback->onServiceDied();
        }
    }
    {
        Mutex::Autolock _l(gLockAPS);
        AudioSystem::gAudioPolicyService.clear();
    }

    ALOGW("AudioPolicyService server died!");
}

void AudioSystem::AudioPolicyServiceClient::onAudioPortListUpdate()
{
    Mutex::Autolock _l(gLockAPC);
    if (gAudioPortCallback != 0) {
        gAudioPortCallback->onAudioPortListUpdate();
    }
}

void AudioSystem::AudioPolicyServiceClient::onAudioPatchListUpdate()
{
    Mutex::Autolock _l(gLockAPC);
    if (gAudioPortCallback != 0) {
        gAudioPortCallback->onAudioPatchListUpdate();
    }
}

}; // namespace android