summaryrefslogtreecommitdiffstats
path: root/src/modules/module-virtual-source.c
blob: d7e1c21c43de96a05c28eb2a4a23abef197264f9 (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
/***
    This file is part of PulseAudio.

    Copyright 2010 Intel Corporation
    Contributor: Pierre-Louis Bossart <pierre-louis.bossart@intel.com>

    PulseAudio is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published
    by the Free Software Foundation; either version 2.1 of the License,
    or (at your option) any later version.

    PulseAudio 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 Lesser General Public License
    along with PulseAudio; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
    USA.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <math.h>

#include <pulse/xmalloc.h>
#include <pulse/i18n.h>

#include <pulsecore/macro.h>
#include <pulsecore/core-error.h>
#include <pulsecore/namereg.h>
#include <pulsecore/sink.h>
#include <pulsecore/module.h>
#include <pulsecore/core-rtclock.h>
#include <pulsecore/core-util.h>
#include <pulsecore/core-error.h>
#include <pulsecore/modargs.h>
#include <pulsecore/log.h>
#include <pulsecore/thread.h>
#include <pulsecore/thread-mq.h>
#include <pulsecore/rtpoll.h>
#include <pulsecore/sample-util.h>
#include <pulsecore/ltdl-helper.h>

#include "module-virtual-source-symdef.h"

PA_MODULE_AUTHOR("Pierre-Louis Bossart");
PA_MODULE_DESCRIPTION("Virtual source");
PA_MODULE_VERSION(PACKAGE_VERSION);
PA_MODULE_LOAD_ONCE(FALSE);
PA_MODULE_USAGE(
        _("source_name=<name for the source> "
          "source_properties=<properties for the source> "
          "master=<name of source to filter> "
          "uplink_sink=<name> (optional)"
          "format=<sample format> "
          "rate=<sample rate> "
          "channels=<number of channels> "
          "channel_map=<channel map> "
        ));

#define MEMBLOCKQ_MAXLENGTH (16*1024*1024)
#define BLOCK_USEC 1000 /* FIXME */

struct userdata {
    pa_module *module;

    pa_source *source;
    pa_source_output *source_output;

    pa_memblockq *memblockq;

    pa_bool_t auto_desc;
    unsigned channels;

    /* optional fields for uplink sink */
    pa_sink *sink;
    pa_usec_t block_usec;
    pa_memblockq *sink_memblockq;

};

static const char* const valid_modargs[] = {
    "source_name",
    "source_properties",
    "master",
    "uplink_sink",
    "format",
    "rate",
    "channels",
    "channel_map",
    NULL
};

/* Called from I/O thread context */
static int sink_process_msg_cb(pa_msgobject *o, int code, void *data, int64_t offset, pa_memchunk *chunk) {

    switch (code) {

        case PA_SINK_MESSAGE_GET_LATENCY:

            /* there's no real latency here */
            *((pa_usec_t*) data) = 0;

            return 0;
    }

    return pa_sink_process_msg(o, code, data, offset, chunk);
}

/* Called from main context */
static int sink_set_state_cb(pa_sink *s, pa_sink_state_t state) {
    struct userdata *u;

    pa_sink_assert_ref(s);
    pa_assert_se(u = s->userdata);

    if (!PA_SINK_IS_LINKED(state)) {
        return 0;
    }

    if (state == PA_SINK_RUNNING) {
        /* need to wake-up source if it was suspended */
        pa_source_suspend(u->source, FALSE, PA_SUSPEND_ALL);

        /* FIXME: if there's no client connected, the source will suspend
           and playback will be stuck. You'd want to prevent the source from
           sleeping when the uplink sink is active; even if the audio is
           discarded at least the app isn't stuck */

    } else {
        /* nothing to do, if the sink becomes idle or suspended let
           module-suspend-idle handle the sources later */
    }

    return 0;
}

static void sink_update_requested_latency_cb(pa_sink *s) {
    struct userdata *u;

    pa_sink_assert_ref(s);
    pa_assert_se(u = s->userdata);

    /* FIXME: there's no latency support */

}


/* Called from I/O thread context */
static void sink_request_rewind_cb(pa_sink *s) {
    struct userdata *u;

    pa_sink_assert_ref(s);
    pa_assert_se(u = s->userdata);

    /* Do nothing */
    pa_sink_process_rewind(u->sink, 0);

}

/* Called from I/O thread context */
static int source_process_msg_cb(pa_msgobject *o, int code, void *data, int64_t offset, pa_memchunk *chunk) {
    struct userdata *u = PA_SOURCE(o)->userdata;

    switch (code) {

        case PA_SOURCE_MESSAGE_GET_LATENCY:

            /* The source is _put() before the source output is, so let's
             * make sure we don't access it in that time. Also, the
             * source output is first shut down, the source second. */
            if (!PA_SOURCE_IS_LINKED(u->source->thread_info.state) ||
                !PA_SOURCE_OUTPUT_IS_LINKED(u->source_output->thread_info.state)) {
                *((pa_usec_t*) data) = 0;
                return 0;
            }

            *((pa_usec_t*) data) =

                /* Get the latency of the master source */
                pa_source_get_latency_within_thread(u->source_output->source) +

                /* Add the latency internal to our source output on top */
                /* FIXME, no idea what I am doing here */
                pa_bytes_to_usec(pa_memblockq_get_length(u->source_output->thread_info.delay_memblockq), &u->source_output->source->sample_spec);

            return 0;
    }

    return pa_source_process_msg(o, code, data, offset, chunk);
}

/* Called from main context */
static int source_set_state_cb(pa_source *s, pa_source_state_t state) {
    struct userdata *u;

    pa_source_assert_ref(s);
    pa_assert_se(u = s->userdata);

    if (!PA_SOURCE_IS_LINKED(state) ||
        !PA_SOURCE_OUTPUT_IS_LINKED(pa_source_output_get_state(u->source_output)))
        return 0;

    pa_source_output_cork(u->source_output, state == PA_SOURCE_SUSPENDED);
    return 0;
}

/* Called from I/O thread context */
static void source_update_requested_latency_cb(pa_source *s) {
    struct userdata *u;

    pa_source_assert_ref(s);
    pa_assert_se(u = s->userdata);

    if (!PA_SOURCE_IS_LINKED(u->source->thread_info.state) ||
        !PA_SOURCE_OUTPUT_IS_LINKED(u->source_output->thread_info.state))
        return;

    /* Just hand this one over to the master source */
    pa_source_output_set_requested_latency_within_thread(
            u->source_output,
            pa_source_get_requested_latency_within_thread(s));
}

/* Called from main context */
static void source_set_volume_cb(pa_source *s) {
    struct userdata *u;

    pa_source_assert_ref(s);
    pa_assert_se(u = s->userdata);

    if (!PA_SOURCE_IS_LINKED(pa_source_get_state(s)) ||
        !PA_SOURCE_OUTPUT_IS_LINKED(pa_source_output_get_state(u->source_output)))
        return;

    /* FIXME, no volume control in source_output, set volume at the master */
    pa_source_set_volume(u->source_output->source, &s->volume, TRUE);
}

static void source_get_volume_cb(pa_source *s) {
    struct userdata *u;

    pa_source_assert_ref(s);
    pa_assert_se(u = s->userdata);

    if (!PA_SOURCE_IS_LINKED(pa_source_get_state(s)) ||
        !PA_SOURCE_OUTPUT_IS_LINKED(pa_source_output_get_state(u->source_output)))
        return;

    /* FIXME, no volume control in source_output, get the info from the master */
    pa_source_get_volume(u->source_output->source, TRUE);

    if (pa_cvolume_equal(&s->volume,&u->source_output->source->volume))
        /* no change */
        return;

    s->volume = u->source_output->source->volume;
    pa_source_set_soft_volume(s, NULL);
}


/* Called from main context */
static void source_set_mute_cb(pa_source *s) {
    struct userdata *u;

    pa_source_assert_ref(s);
    pa_assert_se(u = s->userdata);

    if (!PA_SOURCE_IS_LINKED(pa_source_get_state(s)) ||
        !PA_SOURCE_OUTPUT_IS_LINKED(pa_source_output_get_state(u->source_output)))
        return;

    /* FIXME, no volume control in source_output, set mute at the master */
    pa_source_set_mute(u->source_output->source, TRUE, TRUE);
}

/* Called from main context */
static void source_get_mute_cb(pa_source *s) {
    struct userdata *u;

    pa_source_assert_ref(s);
    pa_assert_se(u = s->userdata);

    if (!PA_SOURCE_IS_LINKED(pa_source_get_state(s)) ||
        !PA_SOURCE_OUTPUT_IS_LINKED(pa_source_output_get_state(u->source_output)))
        return;

    /* FIXME, no volume control in source_output, get the info from the master */
    pa_source_get_mute(u->source_output->source, TRUE);
}

/* Called from input thread context */
static void source_output_push_cb(pa_source_output *o, const pa_memchunk *chunk) {
    struct userdata *u;

    pa_source_output_assert_ref(o);
    pa_source_output_assert_io_context(o);
    pa_assert_se(u = o->userdata);

    if (!PA_SOURCE_OUTPUT_IS_LINKED(pa_source_output_get_state(u->source_output))) {
        pa_log("push when no link?");
        return;
    }

    /* PUT YOUR CODE HERE TO DO SOMETHING WITH THE SOURCE DATA */

    /* if uplink sink exists, pull data from there; simplify by using
       same length as chunk provided by source */
    if(u->sink && (pa_sink_get_state(u->sink) == PA_SINK_RUNNING)) {
        pa_memchunk tchunk;
        size_t nbytes = chunk->length;
        pa_mix_info streams[2];
        pa_memchunk target_chunk;
        void *target;
        int ch;

        /* Hmm, process any rewind request that might be queued up */
        pa_sink_process_rewind(u->sink, 0);

        /* get data from the sink */
        while (pa_memblockq_peek(u->sink_memblockq, &tchunk) < 0) {
            pa_memchunk nchunk;

            /* make sure we get nbytes from the sink with render_full,
               otherwise we cannot mix with the uplink */
            pa_sink_render_full(u->sink, nbytes, &nchunk);
            pa_memblockq_push(u->sink_memblockq, &nchunk);
            pa_memblock_unref(nchunk.memblock);
        }
        pa_assert(tchunk.length == chunk->length);

        /* move the read pointer for sink memblockq */
        pa_memblockq_drop(u->sink_memblockq, tchunk.length);

        /* allocate target chunk */
        /* this could probably be done in-place, but having chunk as both
           the input and output creates issues with reference counts */
        target_chunk.index = 0;
        target_chunk.length = chunk->length;
        pa_assert(target_chunk.length == chunk->length);

        target_chunk.memblock = pa_memblock_new(o->source->core->mempool,
                                                target_chunk.length);
        pa_assert( target_chunk.memblock );

        /* get target pointer */
        target = (void*)((uint8_t*)pa_memblock_acquire(target_chunk.memblock)
                         + target_chunk.index);

        /* set-up mixing structure
           volume was taken care of in sink and source already */
        streams[0].chunk = *chunk;
        for(ch=0;ch<o->sample_spec.channels;ch++)
            streams[0].volume.values[ch] = PA_VOLUME_NORM; /* FIXME */
        streams[0].volume.channels = o->sample_spec.channels;

        streams[1].chunk = tchunk;
        for(ch=0;ch<o->sample_spec.channels;ch++)
            streams[1].volume.values[ch] = PA_VOLUME_NORM; /* FIXME */
        streams[1].volume.channels = o->sample_spec.channels;

        /* do mixing */
        pa_mix(streams,                /* 2 streams to be mixed */
               2,
               target,                 /* put result in target chunk */
               chunk->length,          /* same length as input */
               (const pa_sample_spec *)&o->sample_spec, /* same sample spec for input and output */
               NULL,                   /* no volume information */
               FALSE);                 /* no mute */

        pa_memblock_release(target_chunk.memblock);
        pa_memblock_unref(tchunk.memblock); /* clean-up */

        /* forward the data to the virtual source */
        pa_source_post(u->source, &target_chunk);

        pa_memblock_unref(target_chunk.memblock); /* clean-up */

    } else {
        /* forward the data to the virtual source */
        pa_source_post(u->source, chunk);
    }


}

/* Called from input thread context */
static void source_output_process_rewind_cb(pa_source_output *o, size_t nbytes) {
    struct userdata *u;

    pa_source_output_assert_ref(o);
    pa_source_output_assert_io_context(o);
    pa_assert_se(u = o->userdata);

    /* FIXME, no idea what I am doing here */
#if 0
    pa_asyncmsgq_post(u->asyncmsgq, PA_MSGOBJECT(u->sink_input), SINK_INPUT_MESSAGE_REWIND, NULL, (int64_t) nbytes, NULL, NULL);
    u->send_counter -= (int64_t) nbytes;
#endif
}

/* Called from output thread context */
static int source_output_process_msg_cb(pa_msgobject *obj, int code, void *data, int64_t offset, pa_memchunk *chunk) {

    /* FIXME, nothing to do here ? */

    return pa_source_output_process_msg(obj, code, data, offset, chunk);
}

/* Called from output thread context */
static void source_output_attach_cb(pa_source_output *o) {
    struct userdata *u;

    pa_source_output_assert_ref(o);
    pa_source_output_assert_io_context(o);
    pa_assert_se(u = o->userdata);

    pa_source_set_rtpoll(u->source, o->source->thread_info.rtpoll);
    pa_source_set_latency_range_within_thread(u->source, o->source->thread_info.min_latency, o->source->thread_info.max_latency);
    pa_source_set_fixed_latency_within_thread(u->source, o->source->thread_info.fixed_latency);
    pa_source_set_max_rewind_within_thread(u->source, pa_source_output_get_max_rewind(o));

    pa_source_attach_within_thread(u->source);
}

/* Called from output thread context */
static void source_output_detach_cb(pa_source_output *o) {
    struct userdata *u;

    pa_source_output_assert_ref(o);
    pa_source_output_assert_io_context(o);
    pa_assert_se(u = o->userdata);

    pa_source_detach_within_thread(u->source);
    pa_source_set_rtpoll(u->source, NULL);
}

/* Called from output thread context */
static void source_output_state_change_cb(pa_source_output *o, pa_source_output_state_t state) {
    struct userdata *u;

    pa_source_output_assert_ref(o);
    pa_source_output_assert_io_context(o);
    pa_assert_se(u = o->userdata);

    /* FIXME */
#if 0
    if (PA_SOURCE_OUTPUT_IS_LINKED(state) && o->thread_info.state == PA_SOURCE_OUTPUT_INIT) {

        u->skip = pa_usec_to_bytes(PA_CLIP_SUB(pa_source_get_latency_within_thread(o->source),
                                               u->latency),
                                   &o->sample_spec);

        pa_log_info("Skipping %lu bytes", (unsigned long) u->skip);
    }
#endif
}

/* Called from main thread */
static void source_output_kill_cb(pa_source_output *o) {
    struct userdata *u;

    pa_source_output_assert_ref(o);
    pa_assert_ctl_context();
    pa_assert_se(u = o->userdata);

    /* The order here matters! We first kill the source output, followed
     * by the source. That means the source callbacks must be protected
     * against an unconnected source output! */
    pa_source_output_unlink(u->source_output);
    pa_source_unlink(u->source);

    pa_source_output_unref(u->source_output);
    u->source_output = NULL;

    pa_source_unref(u->source);
    u->source = NULL;

    pa_module_unload_request(u->module, TRUE);
}

/* Called from main thread */
static pa_bool_t source_output_may_move_to_cb(pa_source_output *o, pa_source *dest) {
    struct userdata *u;

    pa_source_output_assert_ref(o);
    pa_assert_ctl_context();
    pa_assert_se(u = o->userdata);

    /* FIXME */
    //return dest != u->source_input->source->monitor_source;

    return TRUE;
}

/* Called from main thread */
static void source_output_moving_cb(pa_source_output *o, pa_source *dest) {
    struct userdata *u;

    pa_source_output_assert_ref(o);
    pa_assert_ctl_context();
    pa_assert_se(u = o->userdata);

    if (dest) {
        pa_source_set_asyncmsgq(u->source, dest->asyncmsgq);
        pa_source_update_flags(u->source, PA_SOURCE_LATENCY|PA_SOURCE_DYNAMIC_LATENCY, dest->flags);
    } else
        pa_source_set_asyncmsgq(u->source, NULL);

    if (u->auto_desc && dest) {
        const char *z;
        pa_proplist *pl;

        pl = pa_proplist_new();
        z = pa_proplist_gets(dest->proplist, PA_PROP_DEVICE_DESCRIPTION);
        pa_proplist_setf(pl, PA_PROP_DEVICE_DESCRIPTION, "Virtual Source %s on %s",
                         pa_proplist_gets(u->source->proplist, "device.vsource.name"), z ? z : dest->name);

        pa_source_update_proplist(u->source, PA_UPDATE_REPLACE, pl);
        pa_proplist_free(pl);
    }
}


int pa__init(pa_module*m) {
    struct userdata *u;
    pa_sample_spec ss;
    pa_channel_map map;
    pa_modargs *ma;
    pa_source *master=NULL;
    pa_source_output_new_data source_output_data;
    pa_source_new_data source_data;

    /* optional for uplink_sink */
    pa_sink_new_data sink_data;
    size_t nbytes;

    pa_assert(m);

    if (!(ma = pa_modargs_new(m->argument, valid_modargs))) {
        pa_log("Failed to parse module arguments.");
        goto fail;
    }

    if (!(master = pa_namereg_get(m->core, pa_modargs_get_value(ma, "master", NULL), PA_NAMEREG_SOURCE))) {
        pa_log("Master source not found");
        goto fail;
    }

    pa_assert(master);

    ss = master->sample_spec;
    ss.format = PA_SAMPLE_FLOAT32;
    map = master->channel_map;
    if (pa_modargs_get_sample_spec_and_channel_map(ma, &ss, &map, PA_CHANNEL_MAP_DEFAULT) < 0) {
        pa_log("Invalid sample format specification or channel map");
        goto fail;
    }


    u = pa_xnew0(struct userdata, 1);
    if (!u) {
        pa_log("Failed to alloc userdata");
        goto fail;
    }
    u->module = m;
    m->userdata = u;
    u->memblockq = pa_memblockq_new(0, MEMBLOCKQ_MAXLENGTH, 0, pa_frame_size(&ss), 1, 1, 0, NULL);
    if (!u->memblockq) {
        pa_log("Failed to create source memblockq.");
        goto fail;
    }
    u->channels = ss.channels;

    /* Create source */
    pa_source_new_data_init(&source_data);
    source_data.driver = __FILE__;
    source_data.module = m;
    if (!(source_data.name = pa_xstrdup(pa_modargs_get_value(ma, "source_name", NULL))))
        source_data.name = pa_sprintf_malloc("%s.vsource", master->name);
    pa_source_new_data_set_sample_spec(&source_data, &ss);
    pa_source_new_data_set_channel_map(&source_data, &map);
    pa_proplist_sets(source_data.proplist, PA_PROP_DEVICE_MASTER_DEVICE, master->name);
    pa_proplist_sets(source_data.proplist, PA_PROP_DEVICE_CLASS, "filter");
    pa_proplist_sets(source_data.proplist, "device.vsource.name", source_data.name);

    if (pa_modargs_get_proplist(ma, "source_properties", source_data.proplist, PA_UPDATE_REPLACE) < 0) {
        pa_log("Invalid properties");
        pa_source_new_data_done(&source_data);
        goto fail;
    }

    if ((u->auto_desc = !pa_proplist_contains(source_data.proplist, PA_PROP_DEVICE_DESCRIPTION))) {
        const char *z;

        z = pa_proplist_gets(master->proplist, PA_PROP_DEVICE_DESCRIPTION);
        pa_proplist_setf(source_data.proplist, PA_PROP_DEVICE_DESCRIPTION, "Virtual Source %s on %s", source_data.name, z ? z : master->name);
    }

    u->source = pa_source_new(m->core, &source_data,
                          PA_SOURCE_HW_MUTE_CTRL|PA_SOURCE_HW_VOLUME_CTRL|PA_SOURCE_DECIBEL_VOLUME|
                          (master->flags & (PA_SOURCE_LATENCY|PA_SOURCE_DYNAMIC_LATENCY)));
    pa_source_new_data_done(&source_data);

    if (!u->source) {
        pa_log("Failed to create source.");
        goto fail;
    }

    u->source->parent.process_msg = source_process_msg_cb;
    u->source->set_state = source_set_state_cb;
    u->source->update_requested_latency = source_update_requested_latency_cb;
    u->source->set_volume = source_set_volume_cb;
    u->source->set_mute = source_set_mute_cb;
    u->source->get_volume = source_get_volume_cb;
    u->source->get_mute = source_get_mute_cb;
    u->source->userdata = u;

    pa_source_set_asyncmsgq(u->source, master->asyncmsgq);

    /* Create source output */
    pa_source_output_new_data_init(&source_output_data);
    source_output_data.driver = __FILE__;
    source_output_data.module = m;
    source_output_data.source = master;
    source_output_data.destination_source = u->source;
    /* FIXME
       source_output_data.flags = PA_SOURCE_OUTPUT_DONT_INHIBIT_AUTO_SUSPEND; */

    pa_proplist_setf(source_output_data.proplist, PA_PROP_MEDIA_NAME, "Virtual Source Stream of %s", pa_proplist_gets(u->source->proplist, PA_PROP_DEVICE_DESCRIPTION));
    pa_proplist_sets(source_output_data.proplist, PA_PROP_MEDIA_ROLE, "filter");
    pa_source_output_new_data_set_sample_spec(&source_output_data, &ss);
    pa_source_output_new_data_set_channel_map(&source_output_data, &map);

    pa_source_output_new(&u->source_output, m->core, &source_output_data);
    pa_source_output_new_data_done(&source_output_data);

    if (!u->source_output)
        goto fail;

    u->source_output->parent.process_msg = source_output_process_msg_cb;
    u->source_output->push = source_output_push_cb;
    u->source_output->process_rewind = source_output_process_rewind_cb;
    u->source_output->kill = source_output_kill_cb;
    u->source_output->attach = source_output_attach_cb;
    u->source_output->detach = source_output_detach_cb;
    u->source_output->state_change = source_output_state_change_cb;
    u->source_output->may_move_to = source_output_may_move_to_cb;
    u->source_output->moving = source_output_moving_cb;
    u->source_output->userdata = u;

    u->source->output_from_master = u->source_output;

    pa_source_put(u->source);
    pa_source_output_put(u->source_output);

    /* Create optional uplink sink */
    pa_sink_new_data_init(&sink_data);
    sink_data.driver = __FILE__;
    sink_data.module = m;
    if ((sink_data.name = pa_xstrdup(pa_modargs_get_value(ma, "uplink_sink", NULL)))) {
        pa_sink_new_data_set_sample_spec(&sink_data, &ss);
        pa_sink_new_data_set_channel_map(&sink_data, &map);
        pa_proplist_sets(sink_data.proplist, PA_PROP_DEVICE_MASTER_DEVICE, master->name);
        pa_proplist_sets(sink_data.proplist, PA_PROP_DEVICE_CLASS, "uplink sink");
        pa_proplist_sets(sink_data.proplist, "device.uplink_sink.name", sink_data.name);

        if ((u->auto_desc = !pa_proplist_contains(sink_data.proplist, PA_PROP_DEVICE_DESCRIPTION))) {
            const char *z;

            z = pa_proplist_gets(master->proplist, PA_PROP_DEVICE_DESCRIPTION);
            pa_proplist_setf(sink_data.proplist, PA_PROP_DEVICE_DESCRIPTION, "Uplink Sink %s on %s", sink_data.name, z ? z : master->name);
        }

        u->sink_memblockq = pa_memblockq_new(0, MEMBLOCKQ_MAXLENGTH, 0, pa_frame_size(&ss), 1, 1, 0, NULL);
        if (!u->sink_memblockq) {
            pa_log("Failed to create sink memblockq.");
            goto fail;
        }

        u->sink = pa_sink_new(m->core, &sink_data, 0);  /* FIXME, sink has no capabilities */
        pa_sink_new_data_done(&sink_data);

        if (!u->sink) {
            pa_log("Failed to create sink.");
            goto fail;
        }

        u->sink->parent.process_msg = sink_process_msg_cb;
        u->sink->update_requested_latency = sink_update_requested_latency_cb;
        u->sink->request_rewind = sink_request_rewind_cb;
        u->sink->set_state = sink_set_state_cb;
        u->sink->userdata = u;

        pa_sink_set_asyncmsgq(u->sink, master->asyncmsgq);

        /* FIXME: no idea what I am doing here */
        u->block_usec = BLOCK_USEC;
        nbytes = pa_usec_to_bytes(u->block_usec, &u->sink->sample_spec);
        pa_sink_set_max_rewind(u->sink, nbytes);
        pa_sink_set_max_request(u->sink, nbytes);

        pa_sink_put(u->sink);
    } else {
        /* optional uplink sink not enabled */
        u->sink = NULL;
    }

    pa_modargs_free(ma);

    return 0;

 fail:
    if (ma)
        pa_modargs_free(ma);

    pa__done(m);

    return -1;
}

int pa__get_n_used(pa_module *m) {
    struct userdata *u;

    pa_assert(m);
    pa_assert_se(u = m->userdata);

    return pa_source_linked_by(u->source);
}

void pa__done(pa_module*m) {
    struct userdata *u;

    pa_assert(m);

    if (!(u = m->userdata))
        return;

    /* See comments in source_output_kill_cb() above regarding
     * destruction order! */

    if (u->source_output)
        pa_source_output_unlink(u->source_output);

    if (u->source)
        pa_source_unlink(u->source);

    if (u->source_output)
        pa_source_output_unref(u->source_output);

    if (u->source)
        pa_source_unref(u->source);

    if (u->sink)
        pa_sink_unref(u->sink);

    if (u->memblockq)
        pa_memblockq_free(u->memblockq);

    if (u->sink_memblockq)
         pa_memblockq_free(u->sink_memblockq);

    pa_xfree(u);
}