summaryrefslogtreecommitdiffstats
path: root/include/hardware/audio.h
blob: acef4991a5d9683cc10a4d4de9d3572b8c319d72 (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
/*
 * Copyright (C) 2011 The Android Open Source Project
 * Copyright (c) 2012, Code Aurora Forum. All rights reserved.
 *
 * 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_HAL_INTERFACE_H
#define ANDROID_AUDIO_HAL_INTERFACE_H

#include <stdint.h>
#include <string.h>
#include <strings.h>
#include <sys/cdefs.h>
#include <sys/types.h>

#include <cutils/bitops.h>

#include <hardware/hardware.h>
#include <system/audio.h>
#include <hardware/audio_effect.h>

__BEGIN_DECLS

/**
 * The id of this module
 */
#define AUDIO_HARDWARE_MODULE_ID "audio"

/**
 * Name of the audio devices to open
 */
#define AUDIO_HARDWARE_INTERFACE "audio_hw_if"


/* Use version 0.1 to be compatible with first generation of audio hw module with version_major
 * hardcoded to 1. No audio module API change.
 */
#define AUDIO_MODULE_API_VERSION_0_1 HARDWARE_MODULE_API_VERSION(0, 1)
#define AUDIO_MODULE_API_VERSION_CURRENT AUDIO_MODULE_API_VERSION_0_1

/* First generation of audio devices had version hardcoded to 0. all devices with versions < 1.0
 * will be considered of first generation API.
 */
#define AUDIO_DEVICE_API_VERSION_0_0 HARDWARE_DEVICE_API_VERSION(0, 0)
#define AUDIO_DEVICE_API_VERSION_1_0 HARDWARE_DEVICE_API_VERSION(1, 0)
#define AUDIO_DEVICE_API_VERSION_2_0 HARDWARE_DEVICE_API_VERSION(2, 0)
#ifndef ICS_AUDIO_BLOB
#define AUDIO_DEVICE_API_VERSION_CURRENT AUDIO_DEVICE_API_VERSION_2_0
#else
#define AUDIO_DEVICE_API_VERSION_CURRENT AUDIO_DEVICE_API_VERSION_1_0
#endif

/**
 * List of known audio HAL modules. This is the base name of the audio HAL
 * library composed of the "audio." prefix, one of the base names below and
 * a suffix specific to the device.
 * e.g: audio.primary.goldfish.so or audio.a2dp.default.so
 */

#define AUDIO_HARDWARE_MODULE_ID_PRIMARY "primary"
#define AUDIO_HARDWARE_MODULE_ID_A2DP "a2dp"
#define AUDIO_HARDWARE_MODULE_ID_USB "usb"
#define AUDIO_HARDWARE_MODULE_ID_REMOTE_SUBMIX "r_submix"

/**************************************/

/**
 *  standard audio parameters that the HAL may need to handle
 */

/**
 *  audio device parameters
 */

/* BT SCO Noise Reduction + Echo Cancellation parameters */
#define AUDIO_PARAMETER_KEY_BT_NREC "bt_headset_nrec"
#define AUDIO_PARAMETER_VALUE_ON "on"
#define AUDIO_PARAMETER_VALUE_OFF "off"

/* TTY mode selection */
#define AUDIO_PARAMETER_KEY_TTY_MODE "tty_mode"
#define AUDIO_PARAMETER_VALUE_TTY_OFF "tty_off"
#define AUDIO_PARAMETER_VALUE_TTY_VCO "tty_vco"
#define AUDIO_PARAMETER_VALUE_TTY_HCO "tty_hco"
#define AUDIO_PARAMETER_VALUE_TTY_FULL "tty_full"

/* A2DP sink address set by framework */
#define AUDIO_PARAMETER_A2DP_SINK_ADDRESS "a2dp_sink_address"

/* Screen state */
#define AUDIO_PARAMETER_KEY_SCREEN_STATE "screen_state"

/**
 *  audio stream parameters
 */

#define AUDIO_PARAMETER_STREAM_ROUTING "routing"            // audio_devices_t
#define AUDIO_PARAMETER_STREAM_FORMAT "format"              // audio_format_t
#define AUDIO_PARAMETER_STREAM_CHANNELS "channels"          // audio_channel_mask_t
#define AUDIO_PARAMETER_STREAM_FRAME_COUNT "frame_count"    // size_t
#define AUDIO_PARAMETER_STREAM_INPUT_SOURCE "input_source"  // audio_source_t
#define AUDIO_PARAMETER_STREAM_SAMPLING_RATE "sampling_rate" // uint32_t

/* Query supported formats. The response is a '|' separated list of strings from
 * audio_format_t enum e.g: "sup_formats=AUDIO_FORMAT_PCM_16_BIT" */
#define AUDIO_PARAMETER_STREAM_SUP_FORMATS "sup_formats"
/* Query supported channel masks. The response is a '|' separated list of strings from
 * audio_channel_mask_t enum e.g: "sup_channels=AUDIO_CHANNEL_OUT_STEREO|AUDIO_CHANNEL_OUT_MONO" */
#define AUDIO_PARAMETER_STREAM_SUP_CHANNELS "sup_channels"
/* Query supported sampling rates. The response is a '|' separated list of integer values e.g:
 * "sup_sampling_rates=44100|48000" */
#define AUDIO_PARAMETER_STREAM_SUP_SAMPLING_RATES "sup_sampling_rates"

/* Query handle fm parameter*/
#define AUDIO_PARAMETER_KEY_HANDLE_FM "handle_fm"

/* Query voip flag */
#define AUDIO_PARAMETER_KEY_VOIP_CHECK "voip_flag"

/* Query Fluence type */
#define AUDIO_PARAMETER_KEY_FLUENCE_TYPE "fluence"

/* Query if surround sound recording is supported */
#define AUDIO_PARAMETER_KEY_SSR "ssr"

/* Query if a2dp  is supported */
#define AUDIO_PARAMETER_KEY_HANDLE_A2DP_DEVICE "isA2dpDeviceSupported"
/**************************************/

/* common audio stream configuration parameters */
struct audio_config {
    uint32_t sample_rate;
    audio_channel_mask_t channel_mask;
    audio_format_t  format;
};

typedef struct audio_config audio_config_t;
#ifdef QCOM_HARDWARE
typedef struct buf_info;
#endif

/* common audio stream parameters and operations */
struct audio_stream {

    /**
     * Return the sampling rate in Hz - eg. 44100.
     */
    uint32_t (*get_sample_rate)(const struct audio_stream *stream);

    /* currently unused - use set_parameters with key
     *    AUDIO_PARAMETER_STREAM_SAMPLING_RATE
     */
    int (*set_sample_rate)(struct audio_stream *stream, uint32_t rate);

    /**
     * Return size of input/output buffer in bytes for this stream - eg. 4800.
     * It should be a multiple of the frame size.  See also get_input_buffer_size.
     */
    size_t (*get_buffer_size)(const struct audio_stream *stream);

    /**
     * Return the channel mask -
     *  e.g. AUDIO_CHANNEL_OUT_STEREO or AUDIO_CHANNEL_IN_STEREO
     */
    audio_channel_mask_t (*get_channels)(const struct audio_stream *stream);

    /**
     * Return the audio format - e.g. AUDIO_FORMAT_PCM_16_BIT
     */
    audio_format_t (*get_format)(const struct audio_stream *stream);

    /* currently unused - use set_parameters with key
     *     AUDIO_PARAMETER_STREAM_FORMAT
     */
    int (*set_format)(struct audio_stream *stream, audio_format_t format);

    /**
     * Put the audio hardware input/output into standby mode.
     * Driver should exit from standby mode at the next I/O operation.
     * Returns 0 on success and <0 on failure.
     */
    int (*standby)(struct audio_stream *stream);

    /** dump the state of the audio input/output device */
    int (*dump)(const struct audio_stream *stream, int fd);

    /** Return the set of device(s) which this stream is connected to */
    audio_devices_t (*get_device)(const struct audio_stream *stream);

    /**
     * Currently unused - set_device() corresponds to set_parameters() with key
     * AUDIO_PARAMETER_STREAM_ROUTING for both input and output.
     * AUDIO_PARAMETER_STREAM_INPUT_SOURCE is an additional information used by
     * input streams only.
     */
    int (*set_device)(struct audio_stream *stream, audio_devices_t device);

    /**
     * set/get audio stream parameters. The function accepts a list of
     * parameter key value pairs in the form: key1=value1;key2=value2;...
     *
     * Some keys are reserved for standard parameters (See AudioParameter class)
     *
     * If the implementation does not accept a parameter change while
     * the output is active but the parameter is acceptable otherwise, it must
     * return -ENOSYS.
     *
     * The audio flinger will put the stream in standby and then change the
     * parameter value.
     */
    int (*set_parameters)(struct audio_stream *stream, const char *kv_pairs);

    /*
     * Returns a pointer to a heap allocated string. The caller is responsible
     * for freeing the memory for it using free().
     */
    char * (*get_parameters)(const struct audio_stream *stream,
                             const char *keys);
    int (*add_audio_effect)(const struct audio_stream *stream,
                             effect_handle_t effect);
    int (*remove_audio_effect)(const struct audio_stream *stream,
                             effect_handle_t effect);
};
typedef struct audio_stream audio_stream_t;

/**
 * audio_stream_out is the abstraction interface for the audio output hardware.
 *
 * It provides information about various properties of the audio output
 * hardware driver.
 */

struct audio_stream_out {
    struct audio_stream common;

    /**
     * Return the audio hardware driver estimated latency in milliseconds.
     */
    uint32_t (*get_latency)(const struct audio_stream_out *stream);

    /**
     * Use this method in situations where audio mixing is done in the
     * hardware. This method serves as a direct interface with hardware,
     * allowing you to directly set the volume as apposed to via the framework.
     * This method might produce multiple PCM outputs or hardware accelerated
     * codecs, such as MP3 or AAC.
     */
    int (*set_volume)(struct audio_stream_out *stream, float left, float right);

    /**
     * Write audio buffer to driver. Returns number of bytes written, or a
     * negative status_t. If at least one frame was written successfully prior to the error,
     * it is suggested that the driver return that successful (short) byte count
     * and then return an error in the subsequent call.
     */
    ssize_t (*write)(struct audio_stream_out *stream, const void* buffer,
                     size_t bytes);

    /* return the number of audio frames written by the audio dsp to DAC since
     * the output has exited standby
     */
    int (*get_render_position)(const struct audio_stream_out *stream,
                               uint32_t *dsp_frames);

#ifdef QCOM_HARDWARE
    /**
     * start audio data rendering
     */
    int (*start)(struct audio_stream_out *stream);

    /**
     * pause audio rendering
     */
    int (*pause)(struct audio_stream_out *stream);

    /**
     * flush audio data with driver
     */
    int (*flush)(struct audio_stream_out *stream);

    /**
     * stop audio data rendering
     */
    int (*stop)(struct audio_stream_out *stream);
#endif

    /**
     * get the local time at which the next write to the audio driver will be presented.
     * The units are microseconds, where the epoch is decided by the local audio HAL.
     */
    int (*get_next_write_timestamp)(const struct audio_stream_out *stream,
                                    int64_t *timestamp);
#ifdef QCOM_HARDWARE
    /**
    * return the current timestamp after quering to the driver
     */
    int (*get_time_stamp)(const struct audio_stream_out *stream,
                               uint64_t *time_stamp);
    /**
    * EOS notification from HAL to Player
     */
    int (*set_observer)(const struct audio_stream_out *stream,
                               void *observer);
    /**
     * Get the physical address of the buffer allocated in the
     * driver
     */
    int (*get_buffer_info) (const struct audio_stream_out *stream,
                                struct buf_info **buf);
    /**
     * Check if next buffer is available. Waits until next buffer is
     * available
     */
    int (*is_buffer_available) (const struct audio_stream_out *stream,
                                     int *isAvail);
#endif

};
typedef struct audio_stream_out audio_stream_out_t;

#ifdef QCOM_HARDWARE
/**
 * audio_broadcast_stream is the abstraction interface for the
 * audio output hardware.
 *
 * It provides information about various properties of the audio output
 * hardware driver.
 */

struct audio_broadcast_stream {
    struct audio_stream common;

    /**
     * return the audio hardware driver latency in milli seconds.
     */
    uint32_t (*get_latency)(const struct audio_broadcast_stream *stream);

    /**
     * Use this method in situations where audio mixing is done in the
     * hardware. This method serves as a direct interface with hardware,
     * allowing you to directly set the volume as apposed to via the framework.
     * This method might produce multiple PCM outputs or hardware accelerated
     * codecs, such as MP3 or AAC.
     */
    int (*set_volume)(struct audio_broadcast_stream *stream, float left, float right);

    int (*mute)(struct audio_broadcast_stream *stream, bool mute);

    int (*start)(struct audio_broadcast_stream *stream, int64_t absTimeToStart);
    /**
     * write audio buffer to driver. Returns number of bytes written
     */
    ssize_t (*write)(struct audio_broadcast_stream *stream, const void* buffer,
                     size_t bytes, int64_t timestamp, int audioType);

};
typedef struct audio_broadcast_stream audio_broadcast_stream_t;
#endif

struct audio_stream_in {
    struct audio_stream common;

    /** set the input gain for the audio driver. This method is for
     *  for future use */
    int (*set_gain)(struct audio_stream_in *stream, float gain);

    /** Read audio buffer in from audio driver. Returns number of bytes read, or a
     *  negative status_t. If at least one frame was read prior to the error,
     *  read should return that byte count and then return an error in the subsequent call.
     */
    ssize_t (*read)(struct audio_stream_in *stream, void* buffer,
                    size_t bytes);

    /**
     * Return the amount of input frames lost in the audio driver since the
     * last call of this function.
     * Audio driver is expected to reset the value to 0 and restart counting
     * upon returning the current value by this function call.
     * Such loss typically occurs when the user space process is blocked
     * longer than the capacity of audio driver buffers.
     *
     * Unit: the number of input audio frames
     */
    uint32_t (*get_input_frames_lost)(struct audio_stream_in *stream);
};
typedef struct audio_stream_in audio_stream_in_t;

/**
 * return the frame size (number of bytes per sample).
 */
static inline size_t audio_stream_frame_size(const struct audio_stream *s)
{
    size_t chan_samp_sz;
    uint32_t chan_mask = s->get_channels(s);
    int format = s->get_format(s);
    char *tmpparam;
    int isParamEqual;

#ifdef QCOM_HARDWARE
    if (audio_is_input_channel(chan_mask)) {
        chan_mask &= (AUDIO_CHANNEL_IN_STEREO | \
                      AUDIO_CHANNEL_IN_MONO );
    }

    tmpparam = s->get_parameters(s, "voip_flag");
    isParamEqual = !strcmp(tmpparam,"voip_flag=1");
    free(tmpparam);
    if(isParamEqual) {
        if(format != AUDIO_FORMAT_PCM_8_BIT)
            return popcount(chan_mask) * sizeof(int16_t);
        else
            return popcount(chan_mask) * sizeof(int8_t);
    }

    if (audio_is_input_channel(chan_mask)) {
        chan_mask &= (AUDIO_CHANNEL_IN_STEREO | \
                      AUDIO_CHANNEL_IN_MONO | \
                      AUDIO_CHANNEL_IN_5POINT1);
    }
#endif

    switch (format) {
#ifdef QCOM_HARDWARE
    case AUDIO_FORMAT_AMR_NB:
        chan_samp_sz = 32;
        break;
    case AUDIO_FORMAT_EVRC:
        chan_samp_sz = 23;
        break;
    case AUDIO_FORMAT_QCELP:
        chan_samp_sz = 35;
        break;
#endif
    case AUDIO_FORMAT_PCM_16_BIT:
        chan_samp_sz = sizeof(int16_t);
        break;
    case AUDIO_FORMAT_PCM_8_BIT:
    default:
        chan_samp_sz = sizeof(int8_t);
        break;
    }

    return popcount(chan_mask) * chan_samp_sz;
}


/**********************************************************************/

/**
 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
 * and the fields of this data structure must begin with hw_module_t
 * followed by module specific information.
 */
struct audio_module {
    struct hw_module_t common;
};

struct audio_hw_device {
    struct hw_device_t common;

    /**
     * used by audio flinger to enumerate what devices are supported by
     * each audio_hw_device implementation.
     *
     * Return value is a bitmask of 1 or more values of audio_devices_t
     *
     * NOTE: audio HAL implementations starting with
     * AUDIO_DEVICE_API_VERSION_2_0 do not implement this function.
     * All supported devices should be listed in audio_policy.conf
     * file and the audio policy manager must choose the appropriate
     * audio module based on information in this file.
     */
    uint32_t (*get_supported_devices)(const struct audio_hw_device *dev);

    /**
     * check to see if the audio hardware interface has been initialized.
     * returns 0 on success, -ENODEV on failure.
     */
    int (*init_check)(const struct audio_hw_device *dev);

    /** set the audio volume of a voice call. Range is between 0.0 and 1.0 */
    int (*set_voice_volume)(struct audio_hw_device *dev, float volume);

    /**
     * set the audio volume for all audio activities other than voice call.
     * Range between 0.0 and 1.0. If any value other than 0 is returned,
     * the software mixer will emulate this capability.
     */
    int (*set_master_volume)(struct audio_hw_device *dev, float volume);

#ifndef ICS_AUDIO_BLOB
    /**
     * Get the current master volume value for the HAL, if the HAL supports
     * master volume control.  AudioFlinger will query this value from the
     * primary audio HAL when the service starts and use the value for setting
     * the initial master volume across all HALs.  HALs which do not support
     * this method may leave it set to NULL.
     */
    int (*get_master_volume)(struct audio_hw_device *dev, float *volume);
#endif

#ifdef QCOM_FM_ENABLED
    /** set the fm audio volume. Range is between 0.0 and 1.0 */
    int (*set_fm_volume)(struct audio_hw_device *dev, float volume);
#endif

    /**
     * set_mode is called when the audio mode changes. AUDIO_MODE_NORMAL mode
     * is for standard audio playback, AUDIO_MODE_RINGTONE when a ringtone is
     * playing, and AUDIO_MODE_IN_CALL when a call is in progress.
     */
    int (*set_mode)(struct audio_hw_device *dev, audio_mode_t mode);

    /* mic mute */
    int (*set_mic_mute)(struct audio_hw_device *dev, bool state);
    int (*get_mic_mute)(const struct audio_hw_device *dev, bool *state);

    /* set/get global audio parameters */
    int (*set_parameters)(struct audio_hw_device *dev, const char *kv_pairs);

    /*
     * Returns a pointer to a heap allocated string. The caller is responsible
     * for freeing the memory for it using free().
     */
    char * (*get_parameters)(const struct audio_hw_device *dev,
                             const char *keys);

    /* Returns audio input buffer size according to parameters passed or
     * 0 if one of the parameters is not supported.
     * See also get_buffer_size which is for a particular stream.
     */
    size_t (*get_input_buffer_size)(const struct audio_hw_device *dev,
#ifndef ICS_AUDIO_BLOB
                                    const struct audio_config *config);
#else
                                    uint32_t sample_rate, int format,
                                    int channel_count);
#endif

    /** This method creates and opens the audio hardware output stream */
#ifndef ICS_AUDIO_BLOB
    int (*open_output_stream)(struct audio_hw_device *dev,
                              audio_io_handle_t handle,
                              audio_devices_t devices,
                              audio_output_flags_t flags,
                              struct audio_config *config,
                              struct audio_stream_out **stream_out);
#else
    int (*open_output_stream)(struct audio_hw_device *dev, uint32_t devices,
                              int *format, uint32_t *channels,
                              uint32_t *sample_rate,
                              struct audio_stream_out **out);
#endif

#ifdef QCOM_ICS_LPA_COMPAT
    /** This method creates and opens the audio hardware output session */
    int (*open_output_session)(struct audio_hw_device *dev, uint32_t devices,
                              int *format, int sessionId,
                              struct audio_stream_out **out);
#endif

    void (*close_output_stream)(struct audio_hw_device *dev,
                                struct audio_stream_out* stream_out);

#ifdef QCOM_HARDWARE
    /** This method creates and opens the audio hardware output
     *  for broadcast stream */
    int (*open_broadcast_stream)(struct audio_hw_device *dev, uint32_t devices,
                                 int format, uint32_t channels,
                                 uint32_t sample_rate,
                                 uint32_t audio_source,
                                 struct audio_broadcast_stream **out);

    void (*close_broadcast_stream)(struct audio_hw_device *dev,
                                   struct audio_broadcast_stream *out);
#endif

    /** This method creates and opens the audio hardware input stream */
#ifndef ICS_AUDIO_BLOB
    int (*open_input_stream)(struct audio_hw_device *dev,
                             audio_io_handle_t handle,
                             audio_devices_t devices,
                             struct audio_config *config,
                             struct audio_stream_in **stream_in);
#else
    int (*open_input_stream)(struct audio_hw_device *dev, uint32_t devices,
                             int *format, uint32_t *channels,
                             uint32_t *sample_rate,
                             audio_in_acoustics_t acoustics,
                             struct audio_stream_in **stream_in);
#endif

    void (*close_input_stream)(struct audio_hw_device *dev,
                               struct audio_stream_in *stream_in);

    /** This method dumps the state of the audio hardware */
    int (*dump)(const struct audio_hw_device *dev, int fd);

#ifndef ICS_AUDIO_BLOB
    /**
     * set the audio mute status for all audio activities.  If any value other
     * than 0 is returned, the software mixer will emulate this capability.
     */
    int (*set_master_mute)(struct audio_hw_device *dev, bool mute);

    /**
     * Get the current master mute status for the HAL, if the HAL supports
     * master mute control.  AudioFlinger will query this value from the primary
     * audio HAL when the service starts and use the value for setting the
     * initial master mute across all HALs.  HALs which do not support this
     * method may leave it set to NULL.
     */
    int (*get_master_mute)(struct audio_hw_device *dev, bool *mute);
#endif
};
typedef struct audio_hw_device audio_hw_device_t;

/** convenience API for opening and closing a supported device */

static inline int audio_hw_device_open(const struct hw_module_t* module,
                                       struct audio_hw_device** device)
{
    return module->methods->open(module, AUDIO_HARDWARE_INTERFACE,
                                 (struct hw_device_t**)device);
}

static inline int audio_hw_device_close(struct audio_hw_device* device)
{
    return device->common.close(&device->common);
}

#ifdef QCOM_HARDWARE
/** Structure to save buffer information for applying effects for
 *  LPA buffers */
struct buf_info {
    int bufsize;
    int nBufs;
    int **buffers;
};

#ifdef __cplusplus
/**
 *Observer class to post the Events from HAL to Flinger
*/
class AudioEventObserver {
public:
    virtual ~AudioEventObserver() {}
    virtual void postEOS(int64_t delayUs) = 0;
};
#endif
#endif
__END_DECLS

#endif  // ANDROID_AUDIO_INTERFACE_H