summaryrefslogtreecommitdiff
path: root/pjmedia/src/pjmedia-audiodev/audiodev.c
blob: 4ccce9f8b0d084632ba7f15e3013bddbf570c20e (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
/* $Id$ */
/* 
 * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
 * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
 */
#include <pjmedia-audiodev/audiodev_imp.h>
#include <pj/assert.h>
#include <pj/errno.h>
#include <pj/log.h>
#include <pj/pool.h>
#include <pj/string.h>

#define THIS_FILE   "audiodev.c"

#define DEFINE_CAP(name, info)	{name, info}

/* Capability names */
static struct cap_info
{
    const char *name;
    const char *info;
} cap_infos[] = 
{
    DEFINE_CAP("ext-fmt",     "Extended/non-PCM format"),
    DEFINE_CAP("latency-in",  "Input latency/buffer size setting"),
    DEFINE_CAP("latency-out", "Output latency/buffer size setting"),
    DEFINE_CAP("vol-in",      "Input volume setting"),
    DEFINE_CAP("vol-out",     "Output volume setting"),
    DEFINE_CAP("meter-in",    "Input meter"),
    DEFINE_CAP("meter-out",   "Output meter"),
    DEFINE_CAP("route-in",    "Input routing"),
    DEFINE_CAP("route-out",   "Output routing"),
    DEFINE_CAP("aec",	      "Accoustic echo cancellation"),
    DEFINE_CAP("aec-tail",    "Tail length setting for AEC"),
    DEFINE_CAP("vad",	      "Voice activity detection"),
    DEFINE_CAP("cng",	      "Comfort noise generation"),
    DEFINE_CAP("plg",	      "Packet loss concealment")
};


/*
 * The device index seen by application and driver is different. 
 *
 * At application level, device index is index to global list of device.
 * At driver level, device index is index to device list on that particular
 * factory only.
 */
#define MAKE_DEV_ID(f_id, index)   (((f_id & 0xFFFF) << 16) | (index & 0xFFFF))
#define GET_INDEX(dev_id)	   ((dev_id) & 0xFFFF)
#define GET_FID(dev_id)		   ((dev_id) >> 16)
#define DEFAULT_DEV_ID		    0


/* extern functions to create factories */
#if PJMEDIA_AUDIO_DEV_HAS_PORTAUDIO
pjmedia_aud_dev_factory* pjmedia_pa_factory(pj_pool_factory *pf);
#endif

#if PJMEDIA_AUDIO_DEV_HAS_COREAUDIO
pjmedia_aud_dev_factory* pjmedia_coreaudio_factory(pj_pool_factory *pf);
#endif

#if PJMEDIA_AUDIO_DEV_HAS_ALSA
pjmedia_aud_dev_factory* pjmedia_alsa_factory(pj_pool_factory *pf);
#endif

#if PJMEDIA_AUDIO_DEV_HAS_OPENSL
pjmedia_aud_dev_factory* pjmedia_opensl_factory(pj_pool_factory *pf);
#endif

#if PJMEDIA_AUDIO_DEV_HAS_ANDROID_JNI
pjmedia_aud_dev_factory* pjmedia_android_factory(pj_pool_factory *pf);
#endif

#if PJMEDIA_AUDIO_DEV_HAS_BB10
pjmedia_aud_dev_factory* pjmedia_bb10_factory(pj_pool_factory *pf);
#endif

#if PJMEDIA_AUDIO_DEV_HAS_WMME
pjmedia_aud_dev_factory* pjmedia_wmme_factory(pj_pool_factory *pf);
#endif

#if PJMEDIA_AUDIO_DEV_HAS_BDIMAD
pjmedia_aud_dev_factory* pjmedia_bdimad_factory(pj_pool_factory *pf);
#endif

#if PJMEDIA_AUDIO_DEV_HAS_SYMB_VAS
pjmedia_aud_dev_factory* pjmedia_symb_vas_factory(pj_pool_factory *pf);
#endif

#if PJMEDIA_AUDIO_DEV_HAS_SYMB_APS
pjmedia_aud_dev_factory* pjmedia_aps_factory(pj_pool_factory *pf);
#endif

#if PJMEDIA_AUDIO_DEV_HAS_SYMB_MDA
pjmedia_aud_dev_factory* pjmedia_symb_mda_factory(pj_pool_factory *pf);
#endif

#if PJMEDIA_AUDIO_DEV_HAS_NULL_AUDIO
pjmedia_aud_dev_factory* pjmedia_null_audio_factory(pj_pool_factory *pf);
#endif

#define MAX_DRIVERS	16
#define MAX_DEVS	64


/* driver structure */
struct driver
{
    /* Creation function */
    pjmedia_aud_dev_factory_create_func_ptr create;
    /* Factory instance */
    pjmedia_aud_dev_factory *f;
    char		     name[32];	/* Driver name			    */
    unsigned		     dev_cnt;	/* Number of devices		    */
    unsigned		     start_idx;	/* Start index in global list	    */
    int			     rec_dev_idx;/* Default capture device.	    */
    int			     play_dev_idx;/* Default playback device	    */
    int			     dev_idx;	/* Default device.		    */
};

/* The audio subsystem */
static struct aud_subsys
{
    unsigned	     init_count;	/* How many times init() is called  */
    pj_pool_factory *pf;		/* The pool factory.		    */

    unsigned	     drv_cnt;		/* Number of drivers.		    */
    struct driver    drv[MAX_DRIVERS];	/* Array of drivers.		    */

    unsigned	     dev_cnt;		/* Total number of devices.	    */
    pj_uint32_t	     dev_list[MAX_DEVS];/* Array of device IDs.		    */

} aud_subsys;

/* API: get capability name/info */
PJ_DEF(const char*) pjmedia_aud_dev_cap_name(pjmedia_aud_dev_cap cap,
					     const char **p_desc)
{
    const char *desc;
    unsigned i;

    if (p_desc==NULL) p_desc = &desc;

    for (i=0; i<PJ_ARRAY_SIZE(cap_infos); ++i) {
	if ((1 << i)==cap)
	    break;
    }

    if (i==PJ_ARRAY_SIZE(cap_infos)) {
	*p_desc = "??";
	return "??";
    }

    *p_desc = cap_infos[i].info;
    return cap_infos[i].name;
}

static pj_status_t get_cap_pointer(const pjmedia_aud_param *param,
				   pjmedia_aud_dev_cap cap,
				   void **ptr,
				   unsigned *size)
{
#define FIELD_INFO(name)    *ptr = (void*)&param->name; \
			    *size = sizeof(param->name)

    switch (cap) {
    case PJMEDIA_AUD_DEV_CAP_EXT_FORMAT:
	FIELD_INFO(ext_fmt);
	break;
    case PJMEDIA_AUD_DEV_CAP_INPUT_LATENCY:
	FIELD_INFO(input_latency_ms);
	break;
    case PJMEDIA_AUD_DEV_CAP_OUTPUT_LATENCY:
	FIELD_INFO(output_latency_ms);
	break;
    case PJMEDIA_AUD_DEV_CAP_INPUT_VOLUME_SETTING:
	FIELD_INFO(input_vol);
	break;
    case PJMEDIA_AUD_DEV_CAP_OUTPUT_VOLUME_SETTING:
	FIELD_INFO(output_vol);
	break;
    case PJMEDIA_AUD_DEV_CAP_INPUT_ROUTE:
	FIELD_INFO(input_route);
	break;
    case PJMEDIA_AUD_DEV_CAP_OUTPUT_ROUTE:
	FIELD_INFO(output_route);
	break;
    case PJMEDIA_AUD_DEV_CAP_EC:
	FIELD_INFO(ec_enabled);
	break;
    case PJMEDIA_AUD_DEV_CAP_EC_TAIL:
	FIELD_INFO(ec_tail_ms);
	break;
    /* vad is no longer in "fmt" in 2.0.
    case PJMEDIA_AUD_DEV_CAP_VAD:
	FIELD_INFO(ext_fmt.vad);
	break;
    */
    case PJMEDIA_AUD_DEV_CAP_CNG:
	FIELD_INFO(cng_enabled);
	break;
    case PJMEDIA_AUD_DEV_CAP_PLC:
	FIELD_INFO(plc_enabled);
	break;
    default:
	return PJMEDIA_EAUD_INVCAP;
    }

#undef FIELD_INFO

    return PJ_SUCCESS;
}

/* API: set cap value to param */
PJ_DEF(pj_status_t) pjmedia_aud_param_set_cap( pjmedia_aud_param *param,
					       pjmedia_aud_dev_cap cap,
					       const void *pval)
{
    void *cap_ptr;
    unsigned cap_size;
    pj_status_t status;

    status = get_cap_pointer(param, cap, &cap_ptr, &cap_size);
    if (status != PJ_SUCCESS)
	return status;

    pj_memcpy(cap_ptr, pval, cap_size);
    param->flags |= cap;

    return PJ_SUCCESS;
}

/* API: get cap value from param */
PJ_DEF(pj_status_t) pjmedia_aud_param_get_cap( const pjmedia_aud_param *param,
					       pjmedia_aud_dev_cap cap,
					       void *pval)
{
    void *cap_ptr;
    unsigned cap_size;
    pj_status_t status;

    status = get_cap_pointer(param, cap, &cap_ptr, &cap_size);
    if (status != PJ_SUCCESS)
	return status;

    if ((param->flags & cap) == 0) {
	pj_bzero(cap_ptr, cap_size);
	return PJMEDIA_EAUD_INVCAP;
    }

    pj_memcpy(pval, cap_ptr, cap_size);
    return PJ_SUCCESS;
}

/* Internal: init driver */
static pj_status_t init_driver(unsigned drv_idx, pj_bool_t refresh)
{
    struct driver *drv = &aud_subsys.drv[drv_idx];
    pjmedia_aud_dev_factory *f;
    unsigned i, dev_cnt;
    pj_status_t status;

    if (!refresh) {
	/* Create the factory */
	f = (*drv->create)(aud_subsys.pf);
	if (!f)
	    return PJ_EUNKNOWN;

	/* Call factory->init() */
	status = f->op->init(f);
	if (status != PJ_SUCCESS) {
	    f->op->destroy(f);
	    return status;
	}
    } else {
	f = drv->f;
    }

    /* Get number of devices */
    dev_cnt = f->op->get_dev_count(f);
    if (dev_cnt + aud_subsys.dev_cnt > MAX_DEVS) {
	PJ_LOG(4,(THIS_FILE, "%d device(s) cannot be registered because"
			      " there are too many devices",
			      aud_subsys.dev_cnt + dev_cnt - MAX_DEVS));
	dev_cnt = MAX_DEVS - aud_subsys.dev_cnt;
    }

    /* enabling this will cause pjsua-lib initialization to fail when there
     * is no sound device installed in the system, even when pjsua has been
     * run with --null-audio
     *
    if (dev_cnt == 0) {
	f->op->destroy(f);
	return PJMEDIA_EAUD_NODEV;
    }
    */

    /* Fill in default devices */
    drv->play_dev_idx = drv->rec_dev_idx = drv->dev_idx = -1;
    for (i=0; i<dev_cnt; ++i) {
	pjmedia_aud_dev_info info;

	status = f->op->get_dev_info(f, i, &info);
	if (status != PJ_SUCCESS) {
	    f->op->destroy(f);
	    return status;
	}

	if (drv->name[0]=='\0') {
	    /* Set driver name */
	    pj_ansi_strncpy(drv->name, info.driver, sizeof(drv->name));
	    drv->name[sizeof(drv->name)-1] = '\0';
	}

	if (drv->play_dev_idx < 0 && info.output_count) {
	    /* Set default playback device */
	    drv->play_dev_idx = i;
	}
	if (drv->rec_dev_idx < 0 && info.input_count) {
	    /* Set default capture device */
	    drv->rec_dev_idx = i;
	}
	if (drv->dev_idx < 0 && info.input_count &&
	    info.output_count)
	{
	    /* Set default capture and playback device */
	    drv->dev_idx = i;
	}

	if (drv->play_dev_idx >= 0 && drv->rec_dev_idx >= 0 && 
	    drv->dev_idx >= 0) 
	{
	    /* Done. */
	    break;
	}
    }

    /* Register the factory */
    drv->f = f;
    drv->f->sys.drv_idx = drv_idx;
    drv->start_idx = aud_subsys.dev_cnt;
    drv->dev_cnt = dev_cnt;

    /* Register devices to global list */
    for (i=0; i<dev_cnt; ++i) {
	aud_subsys.dev_list[aud_subsys.dev_cnt++] = MAKE_DEV_ID(drv_idx, i);
    }

    return PJ_SUCCESS;
}

/* Internal: deinit driver */
static void deinit_driver(unsigned drv_idx)
{
    struct driver *drv = &aud_subsys.drv[drv_idx];

    if (drv->f) {
	drv->f->op->destroy(drv->f);
	drv->f = NULL;
    }

    drv->dev_cnt = 0;
    drv->play_dev_idx = drv->rec_dev_idx = drv->dev_idx = -1;
}

/* API: Initialize the audio subsystem. */
PJ_DEF(pj_status_t) pjmedia_aud_subsys_init(pj_pool_factory *pf)
{
    unsigned i;
    pj_status_t status;

    /* Allow init() to be called multiple times as long as there is matching
     * number of shutdown().
     */
    if (aud_subsys.init_count++ != 0) {
	return PJ_SUCCESS;
    }

    /* Register error subsystem */
    status = pj_register_strerror(PJMEDIA_AUDIODEV_ERRNO_START, 
				  PJ_ERRNO_SPACE_SIZE, 
				  &pjmedia_audiodev_strerror);
    pj_assert(status == PJ_SUCCESS);

    /* Init */
    aud_subsys.pf = pf;
    aud_subsys.drv_cnt = 0;
    aud_subsys.dev_cnt = 0;

    /* Register creation functions */
#if PJMEDIA_AUDIO_DEV_HAS_OPENSL
    aud_subsys.drv[aud_subsys.drv_cnt++].create = &pjmedia_opensl_factory;
#endif
#if PJMEDIA_AUDIO_DEV_HAS_ANDROID_JNI
    aud_subsys.drv[aud_subsys.drv_cnt++].create = &pjmedia_android_factory;
#endif
#if PJMEDIA_AUDIO_DEV_HAS_BB10
    aud_subsys.drv[aud_subsys.drv_cnt++].create = &pjmedia_bb10_factory;
#endif
#if PJMEDIA_AUDIO_DEV_HAS_ALSA
    aud_subsys.drv[aud_subsys.drv_cnt++].create = &pjmedia_alsa_factory;
#endif
#if PJMEDIA_AUDIO_DEV_HAS_COREAUDIO
    aud_subsys.drv[aud_subsys.drv_cnt++].create = &pjmedia_coreaudio_factory;
#endif
#if PJMEDIA_AUDIO_DEV_HAS_PORTAUDIO
    aud_subsys.drv[aud_subsys.drv_cnt++].create = &pjmedia_pa_factory;
#endif
#if PJMEDIA_AUDIO_DEV_HAS_WMME
    aud_subsys.drv[aud_subsys.drv_cnt++].create = &pjmedia_wmme_factory;
#endif
#if PJMEDIA_AUDIO_DEV_HAS_BDIMAD
    aud_subsys.drv[aud_subsys.drv_cnt++].create = &pjmedia_bdimad_factory;
#endif
#if PJMEDIA_AUDIO_DEV_HAS_SYMB_VAS
    aud_subsys.drv[aud_subsys.drv_cnt++].create = &pjmedia_symb_vas_factory;
#endif
#if PJMEDIA_AUDIO_DEV_HAS_SYMB_APS
    aud_subsys.drv[aud_subsys.drv_cnt++].create = &pjmedia_aps_factory;
#endif
#if PJMEDIA_AUDIO_DEV_HAS_SYMB_MDA
    aud_subsys.drv[aud_subsys.drv_cnt++].create = &pjmedia_symb_mda_factory;
#endif
#if PJMEDIA_AUDIO_DEV_HAS_NULL_AUDIO
    aud_subsys.drv[aud_subsys.drv_cnt++].create = &pjmedia_null_audio_factory;
#endif

    /* Initialize each factory and build the device ID list */
    for (i=0; i<aud_subsys.drv_cnt; ++i) {
	status = init_driver(i, PJ_FALSE);
	if (status != PJ_SUCCESS) {
	    deinit_driver(i);
	    continue;
	}
    }

    return aud_subsys.dev_cnt ? PJ_SUCCESS : status;
}

/* API: register an audio device factory to the audio subsystem. */
PJ_DEF(pj_status_t)
pjmedia_aud_register_factory(pjmedia_aud_dev_factory_create_func_ptr adf)
{
    pj_status_t status;

    if (aud_subsys.init_count == 0)
	return PJMEDIA_EAUD_INIT;

    aud_subsys.drv[aud_subsys.drv_cnt].create = adf;
    status = init_driver(aud_subsys.drv_cnt, PJ_FALSE);
    if (status == PJ_SUCCESS) {
	aud_subsys.drv_cnt++;
    } else {
	deinit_driver(aud_subsys.drv_cnt);
    }

    return status;
}

/* API: unregister an audio device factory from the audio subsystem. */
PJ_DEF(pj_status_t)
pjmedia_aud_unregister_factory(pjmedia_aud_dev_factory_create_func_ptr adf)
{
    unsigned i, j;

    if (aud_subsys.init_count == 0)
	return PJMEDIA_EAUD_INIT;

    for (i=0; i<aud_subsys.drv_cnt; ++i) {
	struct driver *drv = &aud_subsys.drv[i];

	if (drv->create == adf) {
	    for (j = drv->start_idx; j < drv->start_idx + drv->dev_cnt; j++)
	    {
		aud_subsys.dev_list[j] = (pj_uint32_t)PJMEDIA_AUD_INVALID_DEV;
	    }

	    deinit_driver(i);
	    pj_bzero(drv, sizeof(*drv));
	    return PJ_SUCCESS;
	}
    }

    return PJMEDIA_EAUD_ERR;
}

/* API: get the pool factory registered to the audio subsystem. */
PJ_DEF(pj_pool_factory*) pjmedia_aud_subsys_get_pool_factory(void)
{
    return aud_subsys.pf;
}

/* API: Shutdown the audio subsystem. */
PJ_DEF(pj_status_t) pjmedia_aud_subsys_shutdown(void)
{
    unsigned i;

    /* Allow shutdown() to be called multiple times as long as there is matching
     * number of init().
     */
    if (aud_subsys.init_count == 0) {
	return PJ_SUCCESS;
    }
    --aud_subsys.init_count;

    if (aud_subsys.init_count == 0) {
	for (i=0; i<aud_subsys.drv_cnt; ++i) {
	    deinit_driver(i);
	}

	aud_subsys.pf = NULL;
    }
    return PJ_SUCCESS;
}

/* API: Refresh the list of sound devices installed in the system. */
PJ_DEF(pj_status_t) pjmedia_aud_dev_refresh(void)
{
    unsigned i;
    
    aud_subsys.dev_cnt = 0;
    for (i=0; i<aud_subsys.drv_cnt; ++i) {
	struct driver *drv = &aud_subsys.drv[i];
	
	if (drv->f && drv->f->op->refresh) {
	    pj_status_t status = drv->f->op->refresh(drv->f);
	    if (status != PJ_SUCCESS) {
		PJ_PERROR(4, (THIS_FILE, status, "Unable to refresh device "
						 "list for %s", drv->name));
	    }
	}
	init_driver(i, PJ_TRUE);
    }
    return PJ_SUCCESS;
}

/* API: Get the number of sound devices installed in the system. */
PJ_DEF(unsigned) pjmedia_aud_dev_count(void)
{
    return aud_subsys.dev_cnt;
}

/* Internal: convert local index to global device index */
static pj_status_t make_global_index(unsigned drv_idx, 
				     pjmedia_aud_dev_index *id)
{
    if (*id < 0) {
	return PJ_SUCCESS;
    }

    /* Check that factory still exists */
    PJ_ASSERT_RETURN(aud_subsys.drv[drv_idx].f, PJ_EBUG);

    /* Check that device index is valid */
    PJ_ASSERT_RETURN(*id>=0 && *id<(int)aud_subsys.drv[drv_idx].dev_cnt, 
		     PJ_EBUG);

    *id += aud_subsys.drv[drv_idx].start_idx;
    return PJ_SUCCESS;
}

/* Internal: lookup device id */
static pj_status_t lookup_dev(pjmedia_aud_dev_index id,
			      pjmedia_aud_dev_factory **p_f,
			      unsigned *p_local_index)
{
    int f_id, index;

    if (id < 0) {
	unsigned i;

	if (id == PJMEDIA_AUD_INVALID_DEV)
	    return PJMEDIA_EAUD_INVDEV;

	for (i=0; i<aud_subsys.drv_cnt; ++i) {
	    struct driver *drv = &aud_subsys.drv[i];
	    if (drv->dev_idx >= 0) {
		id = drv->dev_idx;
		make_global_index(i, &id);
		break;
	    } else if (id==PJMEDIA_AUD_DEFAULT_CAPTURE_DEV && 
		drv->rec_dev_idx >= 0) 
	    {
		id = drv->rec_dev_idx;
		make_global_index(i, &id);
		break;
	    } else if (id==PJMEDIA_AUD_DEFAULT_PLAYBACK_DEV && 
		drv->play_dev_idx >= 0) 
	    {
		id = drv->play_dev_idx;
		make_global_index(i, &id);
		break;
	    }
	}

	if (id < 0) {
	    return PJMEDIA_EAUD_NODEFDEV;
	}
    }

    f_id = GET_FID(aud_subsys.dev_list[id]);
    index = GET_INDEX(aud_subsys.dev_list[id]);

    if (f_id < 0 || f_id >= (int)aud_subsys.drv_cnt)
	return PJMEDIA_EAUD_INVDEV;

    if (index < 0 || index >= (int)aud_subsys.drv[f_id].dev_cnt)
	return PJMEDIA_EAUD_INVDEV;

    *p_f = aud_subsys.drv[f_id].f;
    *p_local_index = (unsigned)index;

    return PJ_SUCCESS;

}

/* API: Get device information. */
PJ_DEF(pj_status_t) pjmedia_aud_dev_get_info(pjmedia_aud_dev_index id,
					     pjmedia_aud_dev_info *info)
{
    pjmedia_aud_dev_factory *f;
    unsigned index;
    pj_status_t status;

    PJ_ASSERT_RETURN(info && id!=PJMEDIA_AUD_INVALID_DEV, PJ_EINVAL);
    PJ_ASSERT_RETURN(aud_subsys.pf, PJMEDIA_EAUD_INIT);

    status = lookup_dev(id, &f, &index);
    if (status != PJ_SUCCESS)
	return status;

    return f->op->get_dev_info(f, index, info);
}

/* API: find device */
PJ_DEF(pj_status_t) pjmedia_aud_dev_lookup( const char *drv_name,
					    const char *dev_name,
					    pjmedia_aud_dev_index *id)
{
    pjmedia_aud_dev_factory *f = NULL;
    unsigned drv_idx, dev_idx;

    PJ_ASSERT_RETURN(drv_name && dev_name && id, PJ_EINVAL);
    PJ_ASSERT_RETURN(aud_subsys.pf, PJMEDIA_EAUD_INIT);

    for (drv_idx=0; drv_idx<aud_subsys.drv_cnt; ++drv_idx) {
	if (!pj_ansi_stricmp(drv_name, aud_subsys.drv[drv_idx].name)) {
	    f = aud_subsys.drv[drv_idx].f;
	    break;
	}
    }

    if (!f)
	return PJ_ENOTFOUND;

    for (dev_idx=0; dev_idx<aud_subsys.drv[drv_idx].dev_cnt; ++dev_idx) {
	pjmedia_aud_dev_info info;
	pj_status_t status;

	status = f->op->get_dev_info(f, dev_idx, &info);
	if (status != PJ_SUCCESS)
	    return status;

	if (!pj_ansi_stricmp(dev_name, info.name))
	    break;
    }

    if (dev_idx==aud_subsys.drv[drv_idx].dev_cnt)
	return PJ_ENOTFOUND;

    *id = dev_idx;
    make_global_index(drv_idx, id);

    return PJ_SUCCESS;
}

/* API: Initialize the audio device parameters with default values for the
 * specified device.
 */
PJ_DEF(pj_status_t) pjmedia_aud_dev_default_param(pjmedia_aud_dev_index id,
						  pjmedia_aud_param *param)
{
    pjmedia_aud_dev_factory *f;
    unsigned index;
    pj_status_t status;

    PJ_ASSERT_RETURN(param && id!=PJMEDIA_AUD_INVALID_DEV, PJ_EINVAL);
    PJ_ASSERT_RETURN(aud_subsys.pf, PJMEDIA_EAUD_INIT);

    status = lookup_dev(id, &f, &index);
    if (status != PJ_SUCCESS)
	return status;

    status = f->op->default_param(f, index, param);
    if (status != PJ_SUCCESS)
	return status;

    /* Normalize device IDs */
    make_global_index(f->sys.drv_idx, &param->rec_id);
    make_global_index(f->sys.drv_idx, &param->play_id);

    return PJ_SUCCESS;
}

/* API: Open audio stream object using the specified parameters. */
PJ_DEF(pj_status_t) pjmedia_aud_stream_create(const pjmedia_aud_param *prm,
					      pjmedia_aud_rec_cb rec_cb,
					      pjmedia_aud_play_cb play_cb,
					      void *user_data,
					      pjmedia_aud_stream **p_aud_strm)
{
    pjmedia_aud_dev_factory *rec_f=NULL, *play_f=NULL, *f=NULL;
    pjmedia_aud_param param;
    pj_status_t status;

    PJ_ASSERT_RETURN(prm && prm->dir && p_aud_strm, PJ_EINVAL);
    PJ_ASSERT_RETURN(aud_subsys.pf, PJMEDIA_EAUD_INIT);
    PJ_ASSERT_RETURN(prm->dir==PJMEDIA_DIR_CAPTURE ||
		     prm->dir==PJMEDIA_DIR_PLAYBACK ||
		     prm->dir==PJMEDIA_DIR_CAPTURE_PLAYBACK,
		     PJ_EINVAL);

    /* Must make copy of param because we're changing device ID */
    pj_memcpy(&param, prm, sizeof(param));

    /* Normalize rec_id */
    if (param.dir & PJMEDIA_DIR_CAPTURE) {
	unsigned index;

	if (param.rec_id < 0)
	    param.rec_id = PJMEDIA_AUD_DEFAULT_CAPTURE_DEV;

	status = lookup_dev(param.rec_id, &rec_f, &index);
	if (status != PJ_SUCCESS)
	    return status;

	param.rec_id = index;
	f = rec_f;
    }

    /* Normalize play_id */
    if (param.dir & PJMEDIA_DIR_PLAYBACK) {
	unsigned index;

	if (param.play_id < 0)
	    param.play_id = PJMEDIA_AUD_DEFAULT_PLAYBACK_DEV;

	status = lookup_dev(param.play_id, &play_f, &index);
	if (status != PJ_SUCCESS)
	    return status;

	param.play_id = index;
	f = play_f;
    }

    PJ_ASSERT_RETURN(f != NULL, PJ_EBUG);

    /* For now, rec_id and play_id must belong to the same factory */
    PJ_ASSERT_RETURN((param.dir != PJMEDIA_DIR_CAPTURE_PLAYBACK) || 
		     (rec_f == play_f),
		     PJMEDIA_EAUD_INVDEV);

    /* Create the stream */
    status = f->op->create_stream(f, &param, rec_cb, play_cb,
				  user_data, p_aud_strm);
    if (status != PJ_SUCCESS)
	return status;

    /* Assign factory id to the stream */
    (*p_aud_strm)->sys.drv_idx = f->sys.drv_idx;
    return PJ_SUCCESS;
}

/* API: Get the running parameters for the specified audio stream. */
PJ_DEF(pj_status_t) pjmedia_aud_stream_get_param(pjmedia_aud_stream *strm,
						 pjmedia_aud_param *param)
{
    pj_status_t status;

    PJ_ASSERT_RETURN(strm && param, PJ_EINVAL);
    PJ_ASSERT_RETURN(aud_subsys.pf, PJMEDIA_EAUD_INIT);

    status = strm->op->get_param(strm, param);
    if (status != PJ_SUCCESS)
	return status;

    /* Normalize device id's */
    make_global_index(strm->sys.drv_idx, &param->rec_id);
    make_global_index(strm->sys.drv_idx, &param->play_id);

    return PJ_SUCCESS;
}

/* API: Get the value of a specific capability of the audio stream. */
PJ_DEF(pj_status_t) pjmedia_aud_stream_get_cap(pjmedia_aud_stream *strm,
					       pjmedia_aud_dev_cap cap,
					       void *value)
{
    return strm->op->get_cap(strm, cap, value);
}

/* API: Set the value of a specific capability of the audio stream. */
PJ_DEF(pj_status_t) pjmedia_aud_stream_set_cap(pjmedia_aud_stream *strm,
					       pjmedia_aud_dev_cap cap,
					       const void *value)
{
    return strm->op->set_cap(strm, cap, value);
}

/* API: Start the stream. */
PJ_DEF(pj_status_t) pjmedia_aud_stream_start(pjmedia_aud_stream *strm)
{
    return strm->op->start(strm);
}

/* API: Stop the stream. */
PJ_DEF(pj_status_t) pjmedia_aud_stream_stop(pjmedia_aud_stream *strm)
{
    return strm->op->stop(strm);
}

/* API: Destroy the stream. */
PJ_DEF(pj_status_t) pjmedia_aud_stream_destroy(pjmedia_aud_stream *strm)
{
    return strm->op->destroy(strm);
}