pulse.c 25.7 KB
Newer Older
1
2
3
4
/*****************************************************************************
 * pulse.c : Pulseaudio output plugin for vlc
 *****************************************************************************
 * Copyright (C) 2008 the VideoLAN team
5
 * Copyright (C) 2009-2011 Rémi Denis-Courmont
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
 *
 * Authors: Martin Hamrle <hamrle @ post . cz>
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

28
#include <math.h>
29
#include <vlc_common.h>
30
#include <vlc_plugin.h>
31
#include <vlc_aout.h>
Rémi Denis-Courmont's avatar
Rémi Denis-Courmont committed
32
#include <vlc_cpu.h>
33
34

#include <pulse/pulseaudio.h>
35
#include <vlc_pulse.h>
36
37
38
#if !PA_CHECK_VERSION(0,9,22)
# include <vlc_xlib.h>
#endif
39
40
41
42

static int  Open        ( vlc_object_t * );
static void Close       ( vlc_object_t * );

43
vlc_module_begin ()
Jean-Baptiste Kempf's avatar
Jean-Baptiste Kempf committed
44
    set_shortname( "PulseAudio" )
45
    set_description( N_("Pulseaudio audio output") )
46
    set_capability( "audio output", 160 )
47
48
    set_category( CAT_AUDIO )
    set_subcategory( SUBCAT_AUDIO_AOUT )
49
    add_shortcut( "pulseaudio", "pa" )
50
51
    set_callbacks( Open, Close )
vlc_module_end ()
52

53
54
55
56
57
58
59
/* TODO:
 * - pause input on policy event
 * - resample to compensate for long term drift
 * - select music or video stream property correctly (?)
 * - set further appropriate stream properties
 * - update output devices list dynamically
 */
60

61
62
/* NOTE:
 * Be careful what you do when the PulseAudio mainloop is held, which is to say
63
 * within PulseAudio callbacks, or after vlc_pa_lock().
64
65
 * In particular, a VLC variable callback cannot be triggered nor deleted with
 * the PulseAudio mainloop lock held, if the callback acquires the lock. */
66

67
68
69
70
struct aout_sys_t
{
    pa_stream *stream; /**< PulseAudio playback stream object */
    pa_context *context; /**< PulseAudio connection context */
71
72
    pa_volume_t base_volume; /**< 0dB reference volume */
    pa_cvolume cvolume; /**< actual sink input volume */
73
    mtime_t paused; /**< Time when (last) paused */
74
75
76
    mtime_t pts; /**< Play time of buffer write offset */
    mtime_t desync; /**< Measured desynchronization */
    unsigned rate; /**< Current stream sample rate */
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
static void sink_input_info_cb(pa_context *, const pa_sink_input_info *,
                               int, void *);

/*** Context ***/
static void context_cb(pa_context *ctx, pa_subscription_event_type_t type,
                       uint32_t idx, void *userdata)
{
    audio_output_t *aout = userdata;
    aout_sys_t *sys = aout->sys;
    pa_operation *op;

    switch (type & PA_SUBSCRIPTION_EVENT_FACILITY_MASK)
    {
      case PA_SUBSCRIPTION_EVENT_SINK_INPUT:
        if (idx != pa_stream_get_index(sys->stream))
            break; /* only interested in our sink input */

        /* Gee... PA will not provide the infos directly in the event. */
        switch (type & PA_SUBSCRIPTION_EVENT_TYPE_MASK)
        {
          case PA_SUBSCRIPTION_EVENT_REMOVE:
            msg_Err(aout, "sink input killed!");
            break;

          default:
            op = pa_context_get_sink_input_info(ctx, idx, sink_input_info_cb,
                                                aout);
            if (likely(op != NULL))
                pa_operation_unref(op);
            break;
        }
        break;

      default: /* unsubscribed facility?! */
        assert(0);
    }
}


118
/*** Sink ***/
119
120
121
static void sink_list_cb(pa_context *c, const pa_sink_info *i, int eol,
                         void *userdata)
{
122
    audio_output_t *aout = userdata;
123
124
125
126
127
128
129
130
131
132
133
134
135
    vlc_value_t val, text;

    if (eol)
        return;
    (void) c;

    msg_Dbg(aout, "listing sink %s (%"PRIu32"): %s", i->name, i->index,
            i->description);
    val.i_int = i->index;
    text.psz_string = (char *)i->description;
    var_Change(aout, "audio-device", VLC_VAR_ADDCHOICE, &val, &text);
}

136
137
138
static void sink_info_cb(pa_context *c, const pa_sink_info *i, int eol,
                         void *userdata)
{
139
    audio_output_t *aout = userdata;
140
    aout_sys_t *sys = aout->sys;
141
142
143
144
145

    if (eol)
        return;
    (void) c;

Rémi Denis-Courmont's avatar
Rémi Denis-Courmont committed
146
147
148
149
150
    /* PulseAudio flat volume NORM / 100% / 0dB corresponds to no software
     * amplification and maximum hardware amplification.
     * VLC maps DEFAULT / 100% to no gain at all (software/hardware).
     * Thus we need to use the sink base_volume as a multiplier,
     * if and only if flat volume is active for our current sink. */
151
152
153
154
    if (i->flags & PA_SINK_FLAT_VOLUME)
        sys->base_volume = i->base_volume;
    else
        sys->base_volume = PA_VOLUME_NORM;
155
    msg_Dbg(aout, "base volume: %"PRIu32, sys->base_volume);
156
157
}

158
159
160
161
162
163
164
165
166
167
168
169
170
171
172

/*** Latency management and lip synchronization ***/
static mtime_t vlc_pa_get_latency(audio_output_t *aout,
                                  pa_context *ctx, pa_stream *s)
{
    pa_usec_t latency;
    int negative;

    if (pa_stream_get_latency(s, &latency, &negative)) {
        vlc_pa_error(aout, "unknown latency", ctx);
        return VLC_TS_INVALID;
    }
    return negative ? -latency : +latency;
}

173
static void stream_reset_sync(pa_stream *s, audio_output_t *aout)
174
{
175
176
    aout_sys_t *sys = aout->sys;
    const unsigned rate = aout->format.i_rate;
177
178
179
180
181
182
183
184
185
186

    sys->pts = VLC_TS_INVALID;
    sys->desync = 0;
    pa_operation *op = pa_stream_update_sample_rate(s, rate, NULL, NULL);
    if (unlikely(op == NULL))
        return;
    pa_operation_unref(op);
    sys->rate = rate;
}

187
188
189
190
191
192
193
/**
 * Starts or resumes the playback stream.
 * Tries start playing back audio samples at the most accurate time
 * in order to minimize desync and resampling during early playback.
 * @note PulseAudio lock required.
 */
static void stream_resync(audio_output_t *aout, pa_stream *s)
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
    aout_sys_t *sys = aout->sys;
    pa_operation *op;
    mtime_t delta;

    assert (pa_stream_is_corked(s) > 0);
    assert (sys->pts != VLC_TS_INVALID);

    delta = vlc_pa_get_latency(aout, sys->context, s);
    if (unlikely(delta == VLC_TS_INVALID))
        delta = 0; /* screwed */

    delta = (sys->pts - mdate()) - delta;

    /* TODO: adjust prebuf instead of padding? */
    if (delta > 0) {
        size_t nb = (delta * sys->rate) / CLOCK_FREQ;
        size_t size = aout->format.i_bytes_per_frame;
        float *zeroes = calloc (nb, size);

        msg_Dbg(aout, "starting with %zu zeroes (%"PRId64" us)", nb,
                delta);
#if 0 /* Fault injector: add delay */
        pa_stream_write(s, zeroes, nb * size, NULL, 0, PA_SEEK_RELATIVE);
        pa_stream_write(s, zeroes, nb * size, NULL, 0, PA_SEEK_RELATIVE);
#endif
        if (likely(zeroes != NULL))
            if (pa_stream_write(s, zeroes, nb * size, free, 0,
                                PA_SEEK_RELATIVE) < 0)
                free(zeroes);
    } else
        msg_Warn(aout, "starting late (%"PRId64" us)", delta);

    op = pa_stream_cork(s, 0, NULL, NULL);
    if (op != NULL)
        pa_operation_unref(op);
    op = pa_stream_trigger(s, NULL, NULL);
    if (op != NULL)
        pa_operation_unref(op);
233
234
}

235
236
static void stream_latency_cb(pa_stream *s, void *userdata)
{
237
    audio_output_t *aout = userdata;
238
    aout_sys_t *sys = aout->sys;
239
240
    mtime_t delta, change;

241
242
    if (pa_stream_is_corked(s))
        return;
243
244
245
246
247
248
249
    if (sys->pts == VLC_TS_INVALID)
    {
        msg_Dbg(aout, "missing latency from input");
        return;
    }

    /* Compute lip desynchronization */
250
251
252
    delta = vlc_pa_get_latency(aout, sys->context, s);
    if (delta == VLC_TS_INVALID)
        return;
253

254
    delta = (sys->pts - mdate()) - delta;
255
256
257
258
259
    change = delta - sys->desync;
    sys->desync = delta;
    //msg_Dbg(aout, "desync: %+"PRId64" us (variation: %+"PRId64" us)",
    //        delta, change);

260
261
262
263
    const unsigned inrate = aout->format.i_rate;
    unsigned outrate = sys->rate;
    bool sync = false;

264
    if (delta < -AOUT_MAX_PTS_DELAY)
265
        msg_Warn(aout, "too late by %"PRId64" us", -delta);
266
    else if (delta > +AOUT_MAX_PTS_ADVANCE)
267
        msg_Warn(aout, "too early by %"PRId64" us", delta);
268
269
270
271
    else if (outrate  == inrate)
        return; /* In sync, do not add unnecessary disturbance! */
    else
        sync = true;
272

273
    /* Compute playback sample rate */
274
    /* This is empirical. Feel free to define something smarter. */
275
276
277
278
279
280
281
282
283
    int adj = sync ? (outrate - inrate)
                   : outrate * (delta + change) / (CLOCK_FREQ << 4);
    /* This avoids too quick rate variation. It sounds really bad and
     * causes unstability (e.g. oscillation around the correct rate). */
    int limit = inrate >> 10;
    /* However, to improve stability and try to converge, closing to the
     * nominal rate is favored over drifting from it. */
    if ((adj > 0) == (sys->rate > inrate))
        limit *= 2;
284
285
286
287
    if (adj > +limit)
        adj = +limit;
    if (adj < -limit)
        adj = -limit;
288
    outrate -= adj;
289
290
291

    /* This keeps the effective rate within specified range
     * (+/-AOUT_MAX_RESAMPLING% - see <vlc_aout.h>) of the nominal rate. */
292
    limit = inrate * AOUT_MAX_RESAMPLING / 100;
293
    if (outrate > inrate + limit)
294
        outrate = inrate + limit;
295
    if (outrate < inrate - limit)
296
297
298
        outrate = inrate - limit;

    /* Apply adjusted sample rate */
299
    if (outrate == sys->rate)
300
301
302
303
304
305
306
        return;
    pa_operation *op = pa_stream_update_sample_rate(s, outrate, NULL, NULL);
    if (unlikely(op == NULL)) {
        vlc_pa_error(aout, "cannot change sample rate", sys->context);
        return;
    }
    pa_operation_unref(op);
307
    msg_Dbg(aout, "changed sample rate to %u Hz",outrate);
308
309
310
    sys->rate = outrate;
}

311
312
313
314
315
316
317
318
319
320
321
322
323
324
325

/*** Stream helpers ***/
static void stream_state_cb(pa_stream *s, void *userdata)
{
    switch (pa_stream_get_state(s)) {
        case PA_STREAM_READY:
        case PA_STREAM_FAILED:
        case PA_STREAM_TERMINATED:
            vlc_pa_signal(0);
        default:
            break;
    }
    (void) userdata;
}

326
327
static void stream_moved_cb(pa_stream *s, void *userdata)
{
328
    audio_output_t *aout = userdata;
329
    aout_sys_t *sys = aout->sys;
330
331
    pa_operation *op;
    uint32_t idx = pa_stream_get_device_index(s);
332

Rémi Denis-Courmont's avatar
Rémi Denis-Courmont committed
333
334
335
336
    msg_Dbg(aout, "connected to sink %"PRIu32": %s", idx,
                  pa_stream_get_device_name(s));
    op = pa_context_get_sink_info_by_index(sys->context, idx,
                                           sink_info_cb, aout);
337
338
    if (likely(op != NULL))
        pa_operation_unref(op);
339
340
341
342

    /* Update the variable if someone else moved our stream */
    var_Change(aout, "audio-device", VLC_VAR_SETVALUE,
               &(vlc_value_t){ .i_int = idx }, NULL);
343
344
}

345
346
static void stream_overflow_cb(pa_stream *s, void *userdata)
{
347
    audio_output_t *aout = userdata;
348
349
350
351
352
353
354

    msg_Err(aout, "overflow");
    (void) s;
}

static void stream_started_cb(pa_stream *s, void *userdata)
{
355
    audio_output_t *aout = userdata;
356
357
358
359
360
361
362

    msg_Dbg(aout, "started");
    (void) s;
}

static void stream_suspended_cb(pa_stream *s, void *userdata)
{
363
    audio_output_t *aout = userdata;
364
365

    msg_Dbg(aout, "suspended");
366
    stream_reset_sync(s, aout);
367
368
369
370
}

static void stream_underflow_cb(pa_stream *s, void *userdata)
{
371
    audio_output_t *aout = userdata;
372
    pa_operation *op;
373

374
375
376
377
    msg_Warn(aout, "underflow");
    op = pa_stream_cork(s, 1, NULL, NULL);
    if (op != NULL)
        pa_operation_unref(op);
378
    stream_reset_sync(s, aout);
379
380
}

381
static int stream_wait(pa_stream *stream)
382
383
384
385
386
387
{
    pa_stream_state_t state;

    while ((state = pa_stream_get_state(stream)) != PA_STREAM_READY) {
        if (state == PA_STREAM_FAILED || state == PA_STREAM_TERMINATED)
            return -1;
388
        vlc_pa_wait();
389
390
391
392
    }
    return 0;
}

393
394
395
396
397
398

/*** Sink input ***/
static void sink_input_info_cb(pa_context *ctx, const pa_sink_input_info *i,
                               int eol, void *userdata)
{
    audio_output_t *aout = userdata;
399
400
    aout_sys_t *sys = aout->sys;
    float volume;
401
402
403

    if (eol)
        return;
404
    (void) ctx;
405

406
    sys->cvolume = i->volume;
407
    volume = pa_cvolume_max(&i->volume) / (float)PA_VOLUME_NORM;
408
409
410
411
412
413
    aout_VolumeHardSet(aout, volume, i->mute);
}


/*** VLC audio output callbacks ***/

414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
/* Memory free callback. The block_t address is in front of the data. */
static void data_free(void *data)
{
    block_t **pp = data, *block;

    memcpy(&block, pp - 1, sizeof (block));
    block_Release(block);
}

static void *data_convert(block_t **pp)
{
    block_t *block = *pp;
    /* In most cases, there is enough head room, and this is really cheap: */
    block = block_Realloc(block, sizeof (block), block->i_buffer);
    *pp = block;
    if (unlikely(block == NULL))
        return NULL;

    memcpy(block->p_buffer, &block, sizeof (block));
    block->p_buffer += sizeof (block);
    block->i_buffer -= sizeof (block);
    return block->p_buffer;
}

438
439
440
/**
 * Queue one audio frame to the playabck stream
 */
441
static void Play(audio_output_t *aout, block_t *block)
442
{
443
    aout_sys_t *sys = aout->sys;
444
445
    pa_stream *s = sys->stream;

446
447
448
449
450
451
452
    const void *ptr = data_convert(&block);
    if (unlikely(ptr == NULL))
        return;

    size_t len = block->i_buffer;
    mtime_t pts = block->i_pts + block->i_length;

453
454
455
456
457
    /* Note: The core already holds the output FIFO lock at this point.
     * Therefore we must not under any circumstances (try to) acquire the
     * output FIFO lock while the PulseAudio threaded main loop lock is held
     * (including from PulseAudio stream callbacks). Otherwise lock inversion
     * will take place, and sooner or later a deadlock. */
458
    vlc_pa_lock();
459

460
461
462
    sys->pts = pts;
    if (pa_stream_is_corked(s) > 0)
        stream_resync(aout, s);
463

464
#if 0 /* Fault injector to test underrun recovery */
Rémi Denis-Courmont's avatar
Rémi Denis-Courmont committed
465
466
    static volatile unsigned u = 0;
    if ((++u % 1000) == 0) {
467
        msg_Err(aout, "fault injection");
468
        pa_operation_unref(pa_stream_flush(s, NULL, NULL));
469
470
471
    }
#endif

472
    if (pa_stream_write(s, ptr, len, data_free, 0, PA_SEEK_RELATIVE) < 0) {
473
        vlc_pa_error(aout, "cannot write", sys->context);
474
        block_Release(block);
475
476
    }

477
    vlc_pa_unlock();
478
479
}

480
481
482
/**
 * Cork or uncork the playback stream
 */
483
static void Pause(audio_output_t *aout, bool paused, mtime_t date)
484
{
485
    aout_sys_t *sys = aout->sys;
486
    pa_stream *s = sys->stream;
487
    pa_operation *op;
488

489
    vlc_pa_lock();
490

491
492
493
494
495
496
497
498
499
500
501
502
503
    if (paused) {
        sys->paused = date;
        op = pa_stream_cork(s, paused, NULL, NULL);
        if (op != NULL)
            pa_operation_unref(op);
    } else {
        assert (sys->paused != VLC_TS_INVALID);
        date -= sys->paused;
        msg_Dbg(aout, "resuming after %"PRId64" us", date);
        sys->paused = VLC_TS_INVALID;
        sys->pts += date;
        stream_resync(aout, s);
    }
504

505
    vlc_pa_unlock();
506
507
}

508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
/**
 * Flush or drain the playback stream
 */
static void Flush(audio_output_t *aout, bool wait)
{
    aout_sys_t *sys = aout->sys;
    pa_stream *s = sys->stream;
    pa_operation *op;

    vlc_pa_lock();

    if (wait)
        op = pa_stream_drain(s, NULL, NULL);
        /* TODO: wait for drain completion*/
    else
        op = pa_stream_flush(s, NULL, NULL);
    if (op != NULL)
        pa_operation_unref(op);
    vlc_pa_unlock();
}

529
static int VolumeSet(audio_output_t *aout, float vol, bool mute)
530
{
531
    aout_sys_t *sys = aout->sys;
532
533
534
    pa_operation *op;
    uint32_t idx = pa_stream_get_index(sys->stream);

535
    pa_cvolume cvolume = sys->cvolume;
536
    pa_volume_t volume = sys->base_volume;
537
538

    pa_cvolume_scale(&cvolume, PA_VOLUME_NORM); /* preserve balance */
539
540
541
542
543
544
545
546

    /* VLC provides the software volume so convert directly to PulseAudio
     * software volume, pa_volume_t. This is not a linear amplification factor
     * so do not use PulseAudio linear amplification! */
    vol *= PA_VOLUME_NORM;
    if (unlikely(vol >= PA_VOLUME_MAX))
        vol = PA_VOLUME_MAX;
    volume = pa_sw_volume_multiply(volume, lround(vol));
547
    pa_sw_cvolume_multiply_scalar(&cvolume, &cvolume, volume);
548

549
    assert(pa_cvolume_valid(&cvolume));
550

551
    vlc_pa_lock();
552
    op = pa_context_set_sink_input_volume(sys->context, idx, &cvolume, NULL, NULL);
553
554
    if (likely(op != NULL))
        pa_operation_unref(op);
555
    op = pa_context_set_sink_input_mute(sys->context, idx, mute, NULL, NULL);
556
557
    if (likely(op != NULL))
        pa_operation_unref(op);
558
    vlc_pa_unlock();
559
560
561

    return 0;
}
562

563
564
565
static int StreamMove(vlc_object_t *obj, const char *varname, vlc_value_t old,
                      vlc_value_t val, void *userdata)
{
566
    audio_output_t *aout = (audio_output_t *)obj;
567
    aout_sys_t *sys = aout->sys;
568
569
570
571
572
    pa_stream *s = userdata;
    pa_operation *op;
    uint32_t idx = pa_stream_get_index(s);
    uint32_t sink_idx = val.i_int;

573
574
    (void) varname; (void) old;

575
    vlc_pa_lock();
576
577
    op = pa_context_move_sink_input_by_index(sys->context, idx, sink_idx,
                                             NULL, NULL);
578
579
580
581
    if (likely(op != NULL)) {
        pa_operation_unref(op);
        msg_Dbg(aout, "moving to sink %"PRIu32, sink_idx);
    } else
582
583
        vlc_pa_error(obj, "cannot move sink", sys->context);
    vlc_pa_unlock();
584
585

    return (op != NULL) ? VLC_SUCCESS : VLC_EGENERIC;
586
587
588
}


589
590
591
/**
 * Create a PulseAudio playback stream, a.k.a. a sink input.
 */
592
static int Open(vlc_object_t *obj)
593
{
594
595
596
597
598
#if !PA_CHECK_VERSION(0,9,22)
    if (!vlc_xlib_init(obj))
        return VLC_EGENERIC;
#endif

599
    audio_output_t *aout = (audio_output_t *)obj;
600
    pa_operation *op;
601

602
603
    /* Sample format specification */
    struct pa_sample_spec ss;
604
    vlc_fourcc_t format = aout->format.i_format;
Danny Wood's avatar
Danny Wood committed
605

606
    switch(format)
Danny Wood's avatar
Danny Wood committed
607
    {
608
        case VLC_CODEC_F64B:
609
            format = VLC_CODEC_F32B;
610
611
        case VLC_CODEC_F32B:
            ss.format = PA_SAMPLE_FLOAT32BE;
612
            break;
613
        case VLC_CODEC_F64L:
614
            format = VLC_CODEC_F32L;
615
616
        case VLC_CODEC_F32L:
            ss.format = PA_SAMPLE_FLOAT32LE;
617
            break;
618
        case VLC_CODEC_FI32:
619
            format = VLC_CODEC_FL32;
620
            ss.format = PA_SAMPLE_FLOAT32NE;
621
            break;
622
623
        case VLC_CODEC_S32B:
            ss.format = PA_SAMPLE_S32BE;
624
            break;
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
        case VLC_CODEC_S32L:
            ss.format = PA_SAMPLE_S32LE;
            break;
        case VLC_CODEC_S24B:
            ss.format = PA_SAMPLE_S24BE;
            break;
        case VLC_CODEC_S24L:
            ss.format = PA_SAMPLE_S24LE;
            break;
        case VLC_CODEC_S16B:
            ss.format = PA_SAMPLE_S16BE;
            break;
        case VLC_CODEC_S16L:
            ss.format = PA_SAMPLE_S16LE;
            break;
        case VLC_CODEC_S8:
641
            format = VLC_CODEC_U8;
642
643
        case VLC_CODEC_U8:
            ss.format = PA_SAMPLE_U8;
644
645
            break;
        default:
646
647
            if (HAVE_FPU)
            {
648
                format = VLC_CODEC_FL32;
649
650
651
652
                ss.format = PA_SAMPLE_FLOAT32NE;
            }
            else
            {
653
                format = VLC_CODEC_S16N;
654
655
656
                ss.format = PA_SAMPLE_S16NE;
            }
            break;
Danny Wood's avatar
Danny Wood committed
657
658
    }

659
660
    ss.rate = aout->format.i_rate;
    ss.channels = aout_FormatNbChannels(&aout->format);
661
    if (!pa_sample_spec_valid(&ss)) {
662
        msg_Err(aout, "unsupported sample specification");
663
        return VLC_EGENERIC;
664
    }
665

666
    /* Channel mapping (order defined in vlc_aout.h) */
667
668
669
    struct pa_channel_map map;
    map.channels = 0;

670
    if (aout->format.i_physical_channels & AOUT_CHAN_LEFT)
671
        map.map[map.channels++] = PA_CHANNEL_POSITION_FRONT_LEFT;
672
    if (aout->format.i_physical_channels & AOUT_CHAN_RIGHT)
673
        map.map[map.channels++] = PA_CHANNEL_POSITION_FRONT_RIGHT;
674
    if (aout->format.i_physical_channels & AOUT_CHAN_MIDDLELEFT)
675
        map.map[map.channels++] = PA_CHANNEL_POSITION_SIDE_LEFT;
676
    if (aout->format.i_physical_channels & AOUT_CHAN_MIDDLERIGHT)
677
        map.map[map.channels++] = PA_CHANNEL_POSITION_SIDE_RIGHT;
678
    if (aout->format.i_physical_channels & AOUT_CHAN_REARLEFT)
679
        map.map[map.channels++] = PA_CHANNEL_POSITION_REAR_LEFT;
680
    if (aout->format.i_physical_channels & AOUT_CHAN_REARRIGHT)
681
        map.map[map.channels++] = PA_CHANNEL_POSITION_REAR_RIGHT;
682
    if (aout->format.i_physical_channels & AOUT_CHAN_REARCENTER)
683
        map.map[map.channels++] = PA_CHANNEL_POSITION_REAR_CENTER;
684
    if (aout->format.i_physical_channels & AOUT_CHAN_CENTER)
685
686
687
688
689
690
    {
        if (ss.channels == 1)
            map.map[map.channels++] = PA_CHANNEL_POSITION_MONO;
        else
            map.map[map.channels++] = PA_CHANNEL_POSITION_FRONT_CENTER;
    }
691
    if (aout->format.i_physical_channels & AOUT_CHAN_LFE)
692
693
694
695
        map.map[map.channels++] = PA_CHANNEL_POSITION_LFE;

    for (unsigned i = 0; map.channels < ss.channels; i++) {
        map.map[map.channels++] = PA_CHANNEL_POSITION_AUX0 + i;
696
        msg_Warn(aout, "mapping channel %"PRIu8" to AUX%u", map.channels, i);
697
    }
698

699
    if (!pa_channel_map_valid(&map)) {
700
        msg_Err(aout, "unsupported channel map");
701
702
        return VLC_EGENERIC;
    } else {
703
        const char *name = pa_channel_map_to_name(&map);
704
        msg_Dbg(aout, "using %s channel map", (name != NULL) ? name : "?");
705
    }
706

707
    /* Stream parameters */
708
709
    const pa_stream_flags_t flags = PA_STREAM_START_CORKED
                                  //| PA_STREAM_INTERPOLATE_TIMING
710
711
                                  | PA_STREAM_AUTO_TIMING_UPDATE
                                  | PA_STREAM_VARIABLE_RATE;
712
713

    struct pa_buffer_attr attr;
714
    attr.maxlength = -1;
715
716
717
718
719
720
    /* PulseAudio assumes that tlength bytes are available in the buffer. Thus
     * we need to be conservative and set the minimum value that the VLC
     * audio decoder thread warrants. Otherwise, PulseAudio buffers will
     * underrun on hardware with large buffers. VLC keeps at least
     * AOUT_MIN_PREPARE and at most AOUT_MAX_PREPARE worth of audio buffers.
     * TODO? tlength could be adaptively increased to reduce wakeups. */
721
    attr.tlength = pa_usec_to_bytes(AOUT_MIN_PREPARE_TIME, &ss);
722
    attr.prebuf = 0; /* trigger manually */
723
724
    attr.minreq = -1;
    attr.fragsize = 0; /* not used for output */
725

726
    /* Allocate structures */
727
    aout_sys_t *sys = malloc(sizeof(*sys));
728
729
    if (unlikely(sys == NULL))
        return VLC_ENOMEM;
730
731
732
733
734
735
736
737

    pa_context *ctx = vlc_pa_connect (obj);
    if (ctx == NULL)
    {
        free (sys);
        return VLC_EGENERIC;
    }

738
    aout->sys = sys;
739
    sys->stream = NULL;
740
    sys->context = ctx;
741
    sys->paused = VLC_TS_INVALID;
742
743
744
    sys->pts = VLC_TS_INVALID;
    sys->desync = 0;
    sys->rate = ss.rate;
745

746
747
748
749
750
751
752
753
    /* Context events */
    const pa_subscription_mask_t mask = PA_SUBSCRIPTION_MASK_SINK_INPUT;

    pa_context_set_subscribe_callback(ctx, context_cb, aout);
    op = pa_context_subscribe(ctx, mask, NULL, NULL);
    if (likely(op != NULL))
       pa_operation_unref(op);

754
    /* Channel volume */
755
    sys->base_volume = PA_VOLUME_NORM;
756
757
    pa_cvolume_set(&sys->cvolume, ss.channels, PA_VOLUME_NORM);

758
    vlc_pa_lock();
759
760
761
    /* Create a playback stream */
    pa_stream *s = pa_stream_new(ctx, "audio stream", &ss, &map);
    if (s == NULL) {
762
        vlc_pa_error(obj, "stream creation failure", ctx);
763
        goto fail;
764
    }
765
    sys->stream = s;
766
    pa_stream_set_state_callback(s, stream_state_cb, NULL);
767
    pa_stream_set_latency_update_callback(s, stream_latency_cb, aout);
768
    pa_stream_set_moved_callback(s, stream_moved_cb, aout);
769
770
771
772
    pa_stream_set_overflow_callback(s, stream_overflow_cb, aout);
    pa_stream_set_started_callback(s, stream_started_cb, aout);
    pa_stream_set_suspended_callback(s, stream_suspended_cb, aout);
    pa_stream_set_underflow_callback(s, stream_underflow_cb, aout);
773

774
    if (pa_stream_connect_playback(s, NULL, &attr, flags, NULL, NULL) < 0
775
776
     || stream_wait(s)) {
        vlc_pa_error(obj, "stream connection failure", ctx);
777
        goto fail;
778
779
    }

780
781
    const struct pa_buffer_attr *pba = pa_stream_get_buffer_attr(s);
    msg_Dbg(aout, "using buffer metrics: maxlength=%u, tlength=%u, "
782
783
            "prebuf=%u, minreq=%u",
            pba->maxlength, pba->tlength, pba->prebuf, pba->minreq);
784

785
786
787
788
789
790
791
792
793
    var_Create(aout, "audio-device", VLC_VAR_INTEGER|VLC_VAR_HASCHOICE);
    var_Change(aout, "audio-device", VLC_VAR_SETTEXT,
               &(vlc_value_t){ .psz_string = (char *)_("Audio device") },
               NULL);
    var_AddCallback (aout, "audio-device", StreamMove, s);
    op = pa_context_get_sink_info_list(ctx, sink_list_cb, aout);
    /* We may need to wait for completion... once LibVLC supports this */
    if (op != NULL)
        pa_operation_unref(op);
794
    stream_moved_cb(s, aout);
795
    vlc_pa_unlock();
796

797
    aout->format.i_format = format;
798
799
    aout->pf_play = Play;
    aout->pf_pause = Pause;
800
    aout->pf_flush = Flush;
801
    aout_VolumeHardInit (aout, VolumeSet);
802
803
804
    return VLC_SUCCESS;

fail:
805
    vlc_pa_unlock();
806
    Close(obj);
807
808
809
    return VLC_EGENERIC;
}

810
811
812
/**
 * Removes a PulseAudio playback stream
 */
813
static void Close (vlc_object_t *obj)
814
{
815
    audio_output_t *aout = (audio_output_t *)obj;
816
    aout_sys_t *sys = aout->sys;
817
818
819
    pa_context *ctx = sys->context;
    pa_stream *s = sys->stream;

820
821
822
823
824
    if (s != NULL) {
        /* The callback takes mainloop lock, so it CANNOT be held here! */
        var_DelCallback (aout, "audio-device", StreamMove, s);
        var_Destroy (aout, "audio-device");

825
        pa_stream_disconnect(s);
826

827
828
829
830
831
832
833
834
        /* Clear all callbacks */
        pa_stream_set_state_callback(s, NULL, NULL);
        pa_stream_set_latency_update_callback(s, NULL, aout);
        pa_stream_set_moved_callback(s, NULL, aout);
        pa_stream_set_overflow_callback(s, NULL, aout);
        pa_stream_set_started_callback(s, NULL, aout);
        pa_stream_set_suspended_callback(s, NULL, aout);
        pa_stream_set_underflow_callback(s, NULL, aout);
835

836
        pa_stream_unref(s);
837
    }
838
839

    vlc_pa_disconnect(obj, ctx);
840
    free(sys);
841
}