1 /*****************************************************************************
2 * alsa.c : alsa plugin for vlc
3 *****************************************************************************
4 * Copyright (C) 2000-2010 the VideoLAN team
5 * Copyright (C) 2009-2011 RĂ©mi Denis-Courmont
7 * Authors: Henri Fallon <henri@videolan.org> - Original Author
8 * Jeffrey Baker <jwbaker@acm.org> - Port to ALSA 1.0 API
9 * John Paul Lorenti <jpl31@columbia.edu> - Device selection
10 * Arnaud de Bossoreille de Ribou <bozo@via.ecp.fr> - S/PDIF and aout3
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
25 *****************************************************************************/
33 #include <vlc_common.h>
34 #include <vlc_plugin.h>
35 #include <vlc_dialog.h>
39 #include <alsa/asoundlib.h>
40 #include <alsa/version.h>
42 /** Private data for an ALSA PCM playback stream */
46 void (*reorder) (void *, size_t, unsigned);
49 #define A52_FRAME_NB 1536
51 static int Open (vlc_object_t *);
52 static void Close (vlc_object_t *);
53 static int FindDevicesCallback( vlc_object_t *p_this, char const *psz_name,
54 vlc_value_t newval, vlc_value_t oldval, void *p_unused );
55 static void GetDevices (vlc_object_t *, module_config_t *, const char *);
57 #define AUDIO_DEV_TEXT N_("Audio output device")
58 #define AUDIO_DEV_LONGTEXT N_("Audio output device (using ALSA syntax).")
59 static const char *const devices[] = {
62 static const char *const devices_text[] = {
66 #define AUDIO_CHAN_TEXT N_("Audio output channels")
67 #define AUDIO_CHAN_LONGTEXT N_("Channels available for audio output." \
68 "If the input has more channels than the output, it will be down-mixed." \
69 "This parameter is ignored when digital pass-through is active.")
70 static const int channels[] = {
71 AOUT_CHAN_CENTER, AOUT_CHANS_STEREO, AOUT_CHANS_4_0, AOUT_CHANS_4_1,
72 AOUT_CHANS_5_0, AOUT_CHANS_5_1, AOUT_CHANS_7_1,
74 static const char *const channels_text[] = {
75 N_("Mono"), N_("Stereo"), N_("Surround 4.0"), N_("Surround 4.1"),
76 N_("Surround 5.0"), N_("Surround 5.1"), N_("Surround 7.1"),
80 set_shortname( "ALSA" )
81 set_description( N_("ALSA audio output") )
82 set_category( CAT_AUDIO )
83 set_subcategory( SUBCAT_AUDIO_AOUT )
84 add_string ("alsa-audio-device", "default",
85 AUDIO_DEV_TEXT, AUDIO_DEV_LONGTEXT, false)
86 change_string_list( devices, devices_text, FindDevicesCallback )
87 change_action_add( FindDevicesCallback, N_("Refresh list") )
88 add_integer ("alsa-audio-channels", AOUT_CHANS_FRONT,
89 AUDIO_CHAN_TEXT, AUDIO_CHAN_LONGTEXT, false)
90 change_integer_list (channels, channels_text)
91 set_capability( "audio output", 150 )
92 set_callbacks( Open, Close )
96 /** Helper for ALSA -> VLC debugging output */
97 static void Dump (vlc_object_t *obj, const char *msg,
98 int (*cb)(void *, snd_output_t *), void *p)
100 snd_output_t *output;
103 if (unlikely(snd_output_buffer_open (&output)))
106 int val = cb (p, output);
109 msg_Warn (obj, "cannot get info: %s", snd_strerror (val));
113 size_t len = snd_output_buffer_string (output, &str);
114 if (len > 0 && str[len - 1])
115 len--; /* strip trailing newline */
116 msg_Dbg (obj, "%s%.*s", msg, (int)len, str);
117 snd_output_close (output);
119 #define Dump(o, m, cb, p) \
120 Dump(VLC_OBJECT(o), m, (int (*)(void *, snd_output_t *))(cb), p)
122 static void DumpDevice (vlc_object_t *obj, snd_pcm_t *pcm)
124 snd_pcm_info_t *info;
126 Dump (obj, " ", snd_pcm_dump, pcm);
127 snd_pcm_info_alloca (&info);
128 if (snd_pcm_info (pcm, info) == 0)
130 msg_Dbg (obj, " device name : %s", snd_pcm_info_get_name (info));
131 msg_Dbg (obj, " device ID : %s", snd_pcm_info_get_id (info));
132 msg_Dbg (obj, " subdevice name: %s",
133 snd_pcm_info_get_subdevice_name (info));
137 static void DumpDeviceStatus (vlc_object_t *obj, snd_pcm_t *pcm)
139 snd_pcm_status_t *status;
141 snd_pcm_status_alloca (&status);
142 snd_pcm_status (pcm, status);
143 Dump (obj, "current status:\n", snd_pcm_status_dump, status);
145 #define DumpDeviceStatus(o, p) DumpDeviceStatus(VLC_OBJECT(o), p)
148 * Initializes list of devices.
150 static void Probe (vlc_object_t *obj, const char *dev)
154 var_Create (obj, "audio-device", VLC_VAR_STRING | VLC_VAR_HASCHOICE);
155 text.psz_string = _("Audio Device");
156 var_Change (obj, "audio-device", VLC_VAR_SETTEXT, &text, NULL);
158 GetDevices (obj, NULL, dev);
160 var_AddCallback (obj, "audio-device", aout_ChannelsRestart, NULL);
164 static void Play (audio_output_t *, block_t *);
165 static void Pause (audio_output_t *, bool, mtime_t);
166 static void PauseDummy (audio_output_t *, bool, mtime_t);
167 static void Flush (audio_output_t *, bool);
168 static void Reorder71 (void *, size_t, unsigned);
170 /** Initializes an ALSA playback stream */
171 static int Open (vlc_object_t *obj)
173 audio_output_t *aout = (audio_output_t *)obj;
175 /* Get device name */
176 char *device = var_InheritString (aout, "alsa-audio-device");
177 if (unlikely(device == NULL))
180 snd_pcm_format_t pcm_format; /* ALSA sample format */
181 vlc_fourcc_t fourcc = aout->format.i_format;
187 pcm_format = SND_PCM_FORMAT_FLOAT64_BE;
190 pcm_format = SND_PCM_FORMAT_FLOAT64_LE;
193 pcm_format = SND_PCM_FORMAT_FLOAT_BE;
196 pcm_format = SND_PCM_FORMAT_FLOAT_LE;
199 fourcc = VLC_CODEC_FL32;
200 pcm_format = SND_PCM_FORMAT_FLOAT;
203 pcm_format = SND_PCM_FORMAT_S32_BE;
206 pcm_format = SND_PCM_FORMAT_S32_LE;
209 pcm_format = SND_PCM_FORMAT_S24_3BE;
212 pcm_format = SND_PCM_FORMAT_S24_3LE;
215 pcm_format = SND_PCM_FORMAT_U24_3BE;
218 pcm_format = SND_PCM_FORMAT_U24_3LE;
221 pcm_format = SND_PCM_FORMAT_S16_BE;
224 pcm_format = SND_PCM_FORMAT_S16_LE;
227 pcm_format = SND_PCM_FORMAT_U16_BE;
230 pcm_format = SND_PCM_FORMAT_U16_LE;
233 pcm_format = SND_PCM_FORMAT_S8;
236 pcm_format = SND_PCM_FORMAT_U8;
239 if (AOUT_FMT_SPDIF(&aout->format))
240 spdif = var_InheritBool (aout, "spdif");
243 fourcc = VLC_CODEC_SPDIFL;
244 pcm_format = SND_PCM_FORMAT_S16;
249 fourcc = VLC_CODEC_FL32;
250 pcm_format = SND_PCM_FORMAT_FLOAT;
254 fourcc = VLC_CODEC_S16N;
255 pcm_format = SND_PCM_FORMAT_S16;
260 /* XXX: maybe this should be shared with other dumb outputs */
261 uint32_t map = var_InheritInteger (aout, "alsa-audio-channels");
262 map &= aout->format.i_physical_channels;
263 if (unlikely(map == 0)) /* WTH? */
264 map = AOUT_CHANS_STEREO;
266 unsigned channels = popcount (map);
267 if (channels < aout_FormatNbChannels (&aout->format))
268 msg_Dbg (aout, "downmixing from %u to %u channels",
269 aout_FormatNbChannels (&aout->format), channels);
271 msg_Dbg (aout, "keeping %u channels", channels);
273 /* Choose the IEC device for S/PDIF output:
274 if the device is overridden by the user then it will be the one.
275 Otherwise we compute the default device based on the output format. */
276 if (spdif && !strcmp (device, "default"))
280 switch (aout->format.i_rate)
283 case freq: aes3 = IEC958_AES3_CON_FS_ ## freq; break;
284 FS( 44100) /* def. */ FS( 48000) FS( 32000)
285 FS( 22050) FS( 24000)
286 FS( 88200) FS(768000) FS( 96000)
287 FS(176400) FS(192000)
290 aes3 = IEC958_AES3_CON_FS_NOTID;
295 if (asprintf (&device,
296 "iec958:AES0=0x%x,AES1=0x%x,AES2=0x%x,AES3=0x%x",
297 IEC958_AES0_CON_EMPHASIS_NONE | IEC958_AES0_NONAUDIO,
298 IEC958_AES1_CON_ORIGINAL | IEC958_AES1_CON_PCM_CODER,
303 /* Allocate structures */
304 aout_sys_t *sys = malloc (sizeof (*sys));
305 if (unlikely(sys == NULL))
312 /* Open the device */
314 /* VLC always has a resampler. No need for ALSA's. */
315 const int mode = SND_PCM_NO_AUTO_RESAMPLE;
317 int val = snd_pcm_open (&pcm, device, SND_PCM_STREAM_PLAYBACK, mode);
318 #if (SND_LIB_VERSION <= 0x010015)
319 # warning Please update alsa-lib to version > 1.0.21a.
320 var_Create (aout->p_libvlc, "alsa-working", VLC_VAR_BOOL);
321 if (val != 0 && var_GetBool (aout->p_libvlc, "alsa-working"))
322 dialog_Fatal (aout, "ALSA version problem",
323 "VLC failed to re-initialize your audio output device.\n"
324 "Please update alsa-lib to version 1.0.22 or higher "
325 "to fix this issue.");
326 var_SetBool (aout->p_libvlc, "alsa-working", !val);
330 #if (SND_LIB_VERSION <= 0x010017)
331 # warning Please update alsa-lib to version > 1.0.23.
332 var_Create (aout->p_libvlc, "alsa-broken", VLC_VAR_BOOL);
333 if (!var_GetBool (aout->p_libvlc, "alsa-broken"))
335 var_SetBool (aout->p_libvlc, "alsa-broken", true);
336 dialog_Fatal (aout, "Potential ALSA version problem",
337 "VLC failed to initialize your audio output device (if any).\n"
338 "Please update alsa-lib to version 1.0.24 or higher "
339 "to try to fix this issue.");
342 msg_Err (aout, "cannot open ALSA device \"%s\": %s", device,
344 dialog_Fatal (aout, _("Audio output failed"),
345 _("The audio device \"%s\" could not be used:\n%s."),
346 device, snd_strerror (val));
353 /* Print some potentially useful debug */
354 msg_Dbg (aout, "using ALSA device: %s", device);
355 DumpDevice (VLC_OBJECT(aout), pcm);
357 /* Get Initial hardware parameters */
358 snd_pcm_hw_params_t *hw;
361 snd_pcm_hw_params_alloca (&hw);
362 snd_pcm_hw_params_any (pcm, hw);
363 Dump (aout, "initial hardware setup:\n", snd_pcm_hw_params_dump, hw);
365 val = snd_pcm_hw_params_set_rate_resample(pcm, hw, 0);
368 msg_Err (aout, "cannot disable resampling: %s", snd_strerror (val));
372 val = snd_pcm_hw_params_set_access (pcm, hw,
373 SND_PCM_ACCESS_RW_INTERLEAVED);
376 msg_Err (aout, "cannot set access mode: %s", snd_strerror (val));
380 /* Set sample format */
381 if (snd_pcm_hw_params_test_format (pcm, hw, pcm_format) == 0)
384 if (snd_pcm_hw_params_test_format (pcm, hw, SND_PCM_FORMAT_FLOAT) == 0)
386 fourcc = VLC_CODEC_FL32;
387 pcm_format = SND_PCM_FORMAT_FLOAT;
390 if (snd_pcm_hw_params_test_format (pcm, hw, SND_PCM_FORMAT_S32) == 0)
392 fourcc = VLC_CODEC_S32N;
393 pcm_format = SND_PCM_FORMAT_S32;
396 if (snd_pcm_hw_params_test_format (pcm, hw, SND_PCM_FORMAT_S16) == 0)
398 fourcc = VLC_CODEC_S16N;
399 pcm_format = SND_PCM_FORMAT_S16;
403 msg_Err (aout, "no supported sample format");
407 val = snd_pcm_hw_params_set_format (pcm, hw, pcm_format);
410 msg_Err (aout, "cannot set sample format: %s", snd_strerror (val));
414 /* Set channels count */
415 /* By default, ALSA plug will pad missing channels with zeroes, which is
416 * usually fine. However, it will also discard extraneous channels, which
417 * is not acceptable. Thus the user must configure the physically
418 * available channels, and VLC will downmix if needed. */
419 val = snd_pcm_hw_params_set_channels (pcm, hw, channels);
422 msg_Err (aout, "cannot set %u channels: %s", channels,
427 /* Set sample rate */
428 unsigned rate = aout->format.i_rate;
429 val = snd_pcm_hw_params_set_rate_near (pcm, hw, &rate, NULL);
432 msg_Err (aout, "cannot set sample rate: %s", snd_strerror (val));
435 if (aout->format.i_rate != rate)
436 msg_Dbg (aout, "resampling from %d Hz to %d Hz",
437 aout->format.i_rate, rate);
439 /* Set buffer size */
440 param = AOUT_MAX_ADVANCE_TIME;
441 val = snd_pcm_hw_params_set_buffer_time_near (pcm, hw, ¶m, NULL);
444 msg_Err (aout, "cannot set buffer duration: %s", snd_strerror (val));
448 val = snd_pcm_hw_params_get_buffer_time (hw, ¶m, NULL);
451 msg_Warn (aout, "cannot get buffer time: %s", snd_strerror(val));
452 param = AOUT_MIN_PREPARE_TIME;
456 #else /* work-around for period-long latency outputs (e.g. PulseAudio): */
457 param = AOUT_MIN_PREPARE_TIME;
459 val = snd_pcm_hw_params_set_period_time_near (pcm, hw, ¶m, NULL);
462 msg_Err (aout, "cannot set period: %s", snd_strerror (val));
466 /* Commit hardware parameters */
467 val = snd_pcm_hw_params (pcm, hw);
470 msg_Err (aout, "cannot commit hardware parameters: %s",
474 Dump (aout, "final HW setup:\n", snd_pcm_hw_params_dump, hw);
476 /* Get Initial software parameters */
477 snd_pcm_sw_params_t *sw;
479 snd_pcm_sw_params_alloca (&sw);
480 snd_pcm_sw_params_current (pcm, sw);
481 Dump (aout, "initial software parameters:\n", snd_pcm_sw_params_dump, sw);
484 //snd_pcm_sw_params_set_avail_min( pcm, sw, i_period_size );
486 val = snd_pcm_sw_params_set_start_threshold (pcm, sw, 1);
489 msg_Err( aout, "unable to set start threshold (%s)",
490 snd_strerror( val ) );
495 /* Commit software parameters. */
496 val = snd_pcm_sw_params (pcm, sw);
499 msg_Err (aout, "cannot commit software parameters: %s",
503 Dump (aout, "final software parameters:\n", snd_pcm_sw_params_dump, sw);
505 val = snd_pcm_prepare (pcm);
508 msg_Err (aout, "cannot prepare device: %s", snd_strerror (val));
512 /* Setup audio_output_t */
513 aout->format.i_format = fourcc;
514 aout->format.i_rate = rate;
517 aout->format.i_bytes_per_frame = AOUT_SPDIF_SIZE;
518 aout->format.i_frame_length = A52_FRAME_NB;
519 aout->pf_volume_set = NULL;
523 aout->format.i_original_channels =
524 aout->format.i_physical_channels = map;
525 switch (popcount (map))
528 sys->reorder = Reorder71;
534 aout_VolumeSoftInit (aout);
537 aout->pf_play = Play;
538 if (snd_pcm_hw_params_can_pause (hw))
539 aout->pf_pause = Pause;
542 aout->pf_pause = PauseDummy;
543 msg_Warn (aout, "device cannot be paused");
545 aout->pf_flush = Flush;
559 * Queues one audio buffer to the hardware.
561 static void Play (audio_output_t *aout, block_t *block)
563 aout_sys_t *sys = aout->sys;
565 if (sys->reorder != NULL)
566 sys->reorder (block->p_buffer, block->i_nb_samples,
567 aout->format.i_bitspersample / 8);
569 snd_pcm_t *pcm = sys->pcm;
570 snd_pcm_sframes_t frames;
571 snd_pcm_state_t state = snd_pcm_state (pcm);
573 if (snd_pcm_delay (pcm, &frames) == 0)
575 mtime_t delay = frames * CLOCK_FREQ / aout->format.i_rate;
577 if (state != SND_PCM_STATE_RUNNING)
579 delay = block->i_pts - (mdate () + delay);
582 if (aout->format.i_format != VLC_CODEC_SPDIFL)
584 frames = (delay * aout->format.i_rate) / CLOCK_FREQ;
585 msg_Dbg (aout, "prepending %ld zeroes", frames);
587 void *z = calloc (frames, aout->format.i_bytes_per_frame);
588 if (likely(z != NULL))
590 snd_pcm_writei (pcm, z, frames);
595 /* Lame fallback if zero padding does not work */
598 msg_Dbg (aout, "deferring start (%"PRId64" us)", delay);
603 msg_Dbg (aout, "starting late (%"PRId64" us)", delay);
606 aout_TimeReport (aout, block->i_pts - delay);
609 /* TODO: better overflow handling */
610 /* TODO: no period wake ups */
612 while (block->i_nb_samples > 0)
614 frames = snd_pcm_writei (pcm, block->p_buffer, block->i_nb_samples);
617 size_t bytes = snd_pcm_frames_to_bytes (pcm, frames);
618 block->i_nb_samples -= frames;
619 block->p_buffer += bytes;
620 block->i_buffer -= bytes;
625 int val = snd_pcm_recover (pcm, frames, 1);
628 msg_Err (aout, "cannot recover playback stream: %s",
630 DumpDeviceStatus (aout, pcm);
633 msg_Warn (aout, "cannot write samples: %s", snd_strerror (frames));
636 block_Release (block);
640 * Pauses/resumes the audio playback.
642 static void Pause (audio_output_t *aout, bool pause, mtime_t date)
644 snd_pcm_t *pcm = aout->sys->pcm;
646 int val = snd_pcm_pause (pcm, pause);
648 PauseDummy (aout, pause, date);
651 static void PauseDummy (audio_output_t *aout, bool pause, mtime_t date)
653 snd_pcm_t *pcm = aout->sys->pcm;
655 /* Stupid device cannot pause. Discard samples. */
659 snd_pcm_prepare (pcm);
664 * Flushes/drains the audio playback buffer.
666 static void Flush (audio_output_t *aout, bool wait)
668 snd_pcm_t *pcm = aout->sys->pcm;
674 snd_pcm_prepare (pcm);
679 * Releases the audio output.
681 static void Close (vlc_object_t *obj)
683 audio_output_t *aout = (audio_output_t *)obj;
684 aout_sys_t *sys = aout->sys;
685 snd_pcm_t *pcm = aout->sys->pcm;
687 /* FIXME: ugly hack so selected ALSA device survives restart */
688 char *device = var_InheritString (obj, "audio-device");
691 if (!var_Type (obj, "alsa-audio-device"))
692 var_Create (obj, "alsa-audio-device", VLC_VAR_STRING);
693 var_SetString (obj, "alsa-audio-device", device);
697 var_DelCallback (obj, "audio-device", aout_ChannelsRestart, NULL);
698 var_Destroy (obj, "audio-device");
705 * Converts from VLC to ALSA order for 7.1.
706 * VLC has middle channels in position 2 and 3, ALSA in position 6 and 7.
708 static void Reorder71 (void *p, size_t n, unsigned size)
713 for (uint64_t *ptr = p; n > 0; ptr += 4, n--)
715 uint64_t middle = ptr[1], c_lfe = ptr[2], rear = ptr[3];
716 ptr[1] = c_lfe; ptr[2] = rear; ptr[3] = middle;
720 for (uint32_t *ptr = p; n > 0; ptr += 4, n--)
722 uint32_t middle = ptr[1], c_lfe = ptr[2], rear = ptr[3];
723 ptr[1] = c_lfe; ptr[2] = rear; ptr[3] = middle;
728 for (uint16_t *ptr = p; n > 0; n--)
730 uint16_t middle[size];
731 memcpy (middle, ptr + size, size * 2);
733 memcpy (ptr, ptr + size, size * 2);
735 memcpy (ptr, ptr + size, size * 2);
737 memcpy (ptr, middle, size * 2);
745 /*****************************************************************************
746 * config variable callback
747 *****************************************************************************/
748 static int FindDevicesCallback( vlc_object_t *p_this, char const *psz_name,
749 vlc_value_t newval, vlc_value_t oldval, void *p_unused )
751 module_config_t *p_item;
756 p_item = config_FindConfig( p_this, psz_name );
757 if( !p_item ) return VLC_SUCCESS;
759 /* Clear-up the current list */
764 /* Keep the first entrie */
765 for( i = 1; i < p_item->i_list; i++ )
767 free( (char *)p_item->ppsz_list[i] );
768 free( (char *)p_item->ppsz_list_text[i] );
770 /* TODO: Remove when no more needed */
771 p_item->ppsz_list[i] = NULL;
772 p_item->ppsz_list_text[i] = NULL;
776 GetDevices (p_this, p_item, "default");
782 static void GetDevices (vlc_object_t *obj, module_config_t *item,
783 const char *prefs_dev)
786 bool hinted_default = false;
787 bool hinted_prefs = !strcmp (prefs_dev, "default");
789 msg_Dbg(obj, "Available ALSA PCM devices:");
791 if (snd_device_name_hint(-1, "pcm", &hints) < 0)
794 for (size_t i = 0; hints[i] != NULL; i++)
796 void *hint = hints[i];
798 char *name = snd_device_name_get_hint(hint, "NAME");
799 if (unlikely(name == NULL))
802 char *desc = snd_device_name_get_hint(hint, "DESC");
804 for (char *lf = strchr(desc, '\n'); lf; lf = strchr(lf, '\n'))
806 msg_Dbg(obj, "%s (%s)", (desc != NULL) ? desc : name, name);
808 if (!strcmp (name, "default"))
809 hinted_default = true;
810 if (!strcmp (name, prefs_dev))
815 item->ppsz_list = xrealloc(item->ppsz_list,
816 (item->i_list + 2) * sizeof(char *));
817 item->ppsz_list_text = xrealloc(item->ppsz_list_text,
818 (item->i_list + 2) * sizeof(char *));
819 item->ppsz_list[item->i_list] = name;
822 item->ppsz_list_text[item->i_list] = desc;
827 vlc_value_t val, text;
829 val.psz_string = name;
830 text.psz_string = desc;
831 var_Change(obj, "audio-device", VLC_VAR_ADDCHOICE, &val, &text);
837 snd_device_name_free_hint(hints);
841 item->ppsz_list[item->i_list] = NULL;
842 item->ppsz_list_text[item->i_list] = NULL;
846 vlc_value_t val, text;
850 val.psz_string = (char *)"default";
851 text.psz_string = (char *)N_("Default");
852 var_Change(obj, "audio-device", VLC_VAR_ADDCHOICE, &val, &text);
855 val.psz_string = (char *)prefs_dev;
858 text.psz_string = (char *)N_("VLC preferences");
859 var_Change(obj, "audio-device", VLC_VAR_ADDCHOICE, &val, &text);
861 var_Change(obj, "audio-device", VLC_VAR_SETVALUE, &val, NULL);