1 /* GStreamer
2  * Copyright (C) 2005 Wim Taymans <wim@fluendo.com>
3  *
4  * gstalsasrc.c:
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Library General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Library General Public License for more details.
15  *
16  * You should have received a copy of the GNU Library General Public
17  * License along with this library; if not, write to the
18  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19  * Boston, MA 02110-1301, USA.
20  */
21 
22 /**
23  * SECTION:element-alsasrc
24  * @title: alsasrc
25  * @see_also: alsasink
26  *
27  * This element reads data from an audio card using the ALSA API.
28  *
29  * ## Example pipelines
30  * |[
31  * gst-launch-1.0 -v alsasrc ! queue ! audioconvert ! vorbisenc ! oggmux ! filesink location=alsasrc.ogg
32  * ]|
33  *  Record from a sound card using ALSA and encode to Ogg/Vorbis.
34  *
35  */
36 
37 #ifdef HAVE_CONFIG_H
38 #include "config.h"
39 #endif
40 #include <sys/ioctl.h>
41 #include <fcntl.h>
42 #include <errno.h>
43 #include <unistd.h>
44 #include <string.h>
45 #include <getopt.h>
46 #include <alsa/asoundlib.h>
47 
48 #include "gstalsasrc.h"
49 #include "gstalsadeviceprobe.h"
50 
51 #include <gst/gst-i18n-plugin.h>
52 
53 #ifndef ESTRPIPE
54 #define ESTRPIPE EPIPE
55 #endif
56 
57 #define DEFAULT_PROP_DEVICE		"default"
58 #define DEFAULT_PROP_DEVICE_NAME	""
59 #define DEFAULT_PROP_CARD_NAME	        ""
60 
61 enum
62 {
63   PROP_0,
64   PROP_DEVICE,
65   PROP_DEVICE_NAME,
66   PROP_CARD_NAME,
67   PROP_LAST
68 };
69 
70 #define gst_alsasrc_parent_class parent_class
71 G_DEFINE_TYPE (GstAlsaSrc, gst_alsasrc, GST_TYPE_AUDIO_SRC);
72 
73 static void gst_alsasrc_finalize (GObject * object);
74 static void gst_alsasrc_set_property (GObject * object,
75     guint prop_id, const GValue * value, GParamSpec * pspec);
76 static void gst_alsasrc_get_property (GObject * object,
77     guint prop_id, GValue * value, GParamSpec * pspec);
78 static GstStateChangeReturn gst_alsasrc_change_state (GstElement * element,
79     GstStateChange transition);
80 static GstCaps *gst_alsasrc_getcaps (GstBaseSrc * bsrc, GstCaps * filter);
81 
82 static gboolean gst_alsasrc_open (GstAudioSrc * asrc);
83 static gboolean gst_alsasrc_prepare (GstAudioSrc * asrc,
84     GstAudioRingBufferSpec * spec);
85 static gboolean gst_alsasrc_unprepare (GstAudioSrc * asrc);
86 static gboolean gst_alsasrc_close (GstAudioSrc * asrc);
87 static guint gst_alsasrc_read
88     (GstAudioSrc * asrc, gpointer data, guint length, GstClockTime * timestamp);
89 static guint gst_alsasrc_delay (GstAudioSrc * asrc);
90 static void gst_alsasrc_reset (GstAudioSrc * asrc);
91 
92 /* AlsaSrc signals and args */
93 enum
94 {
95   LAST_SIGNAL
96 };
97 
98 #if (G_BYTE_ORDER == G_LITTLE_ENDIAN)
99 # define ALSA_SRC_FACTORY_ENDIANNESS   "LITTLE_ENDIAN, BIG_ENDIAN"
100 #else
101 # define ALSA_SRC_FACTORY_ENDIANNESS   "BIG_ENDIAN, LITTLE_ENDIAN"
102 #endif
103 
104 static GstStaticPadTemplate alsasrc_src_factory =
105 GST_STATIC_PAD_TEMPLATE ("src",
106     GST_PAD_SRC,
107     GST_PAD_ALWAYS,
108     GST_STATIC_CAPS ("audio/x-raw, "
109         "format = (string) " GST_AUDIO_FORMATS_ALL ", "
110         "layout = (string) interleaved, "
111         "rate = (int) [ 1, MAX ], " "channels = (int) [ 1, MAX ]")
112     );
113 
114 static void
gst_alsasrc_finalize(GObject * object)115 gst_alsasrc_finalize (GObject * object)
116 {
117   GstAlsaSrc *src = GST_ALSA_SRC (object);
118 
119   g_free (src->device);
120   g_mutex_clear (&src->alsa_lock);
121 
122   G_OBJECT_CLASS (parent_class)->finalize (object);
123 }
124 
125 static void
gst_alsasrc_class_init(GstAlsaSrcClass * klass)126 gst_alsasrc_class_init (GstAlsaSrcClass * klass)
127 {
128   GObjectClass *gobject_class;
129   GstElementClass *gstelement_class;
130   GstBaseSrcClass *gstbasesrc_class;
131   GstAudioSrcClass *gstaudiosrc_class;
132 
133   gobject_class = (GObjectClass *) klass;
134   gstelement_class = (GstElementClass *) klass;
135   gstbasesrc_class = (GstBaseSrcClass *) klass;
136   gstaudiosrc_class = (GstAudioSrcClass *) klass;
137 
138   gobject_class->finalize = gst_alsasrc_finalize;
139   gobject_class->get_property = gst_alsasrc_get_property;
140   gobject_class->set_property = gst_alsasrc_set_property;
141 
142   gst_element_class_set_static_metadata (gstelement_class,
143       "Audio source (ALSA)", "Source/Audio",
144       "Read from a sound card via ALSA", "Wim Taymans <wim@fluendo.com>");
145 
146   gst_element_class_add_static_pad_template (gstelement_class,
147       &alsasrc_src_factory);
148 
149   gstbasesrc_class->get_caps = GST_DEBUG_FUNCPTR (gst_alsasrc_getcaps);
150 
151   gstaudiosrc_class->open = GST_DEBUG_FUNCPTR (gst_alsasrc_open);
152   gstaudiosrc_class->prepare = GST_DEBUG_FUNCPTR (gst_alsasrc_prepare);
153   gstaudiosrc_class->unprepare = GST_DEBUG_FUNCPTR (gst_alsasrc_unprepare);
154   gstaudiosrc_class->close = GST_DEBUG_FUNCPTR (gst_alsasrc_close);
155   gstaudiosrc_class->read = GST_DEBUG_FUNCPTR (gst_alsasrc_read);
156   gstaudiosrc_class->delay = GST_DEBUG_FUNCPTR (gst_alsasrc_delay);
157   gstaudiosrc_class->reset = GST_DEBUG_FUNCPTR (gst_alsasrc_reset);
158   gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_alsasrc_change_state);
159 
160   g_object_class_install_property (gobject_class, PROP_DEVICE,
161       g_param_spec_string ("device", "Device",
162           "ALSA device, as defined in an asound configuration file",
163           DEFAULT_PROP_DEVICE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
164 
165   g_object_class_install_property (gobject_class, PROP_DEVICE_NAME,
166       g_param_spec_string ("device-name", "Device name",
167           "Human-readable name of the sound device",
168           DEFAULT_PROP_DEVICE_NAME, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
169 
170   g_object_class_install_property (gobject_class, PROP_CARD_NAME,
171       g_param_spec_string ("card-name", "Card name",
172           "Human-readable name of the sound card",
173           DEFAULT_PROP_CARD_NAME, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
174 }
175 
176 static void
gst_alsasrc_set_property(GObject * object,guint prop_id,const GValue * value,GParamSpec * pspec)177 gst_alsasrc_set_property (GObject * object, guint prop_id,
178     const GValue * value, GParamSpec * pspec)
179 {
180   GstAlsaSrc *src;
181 
182   src = GST_ALSA_SRC (object);
183 
184   switch (prop_id) {
185     case PROP_DEVICE:
186       g_free (src->device);
187       src->device = g_value_dup_string (value);
188       if (src->device == NULL) {
189         src->device = g_strdup (DEFAULT_PROP_DEVICE);
190       }
191       break;
192     default:
193       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
194       break;
195   }
196 }
197 
198 static void
gst_alsasrc_get_property(GObject * object,guint prop_id,GValue * value,GParamSpec * pspec)199 gst_alsasrc_get_property (GObject * object, guint prop_id,
200     GValue * value, GParamSpec * pspec)
201 {
202   GstAlsaSrc *src;
203 
204   src = GST_ALSA_SRC (object);
205 
206   switch (prop_id) {
207     case PROP_DEVICE:
208       g_value_set_string (value, src->device);
209       break;
210     case PROP_DEVICE_NAME:
211       g_value_take_string (value,
212           gst_alsa_find_device_name (GST_OBJECT_CAST (src),
213               src->device, src->handle, SND_PCM_STREAM_CAPTURE));
214       break;
215     case PROP_CARD_NAME:
216       g_value_take_string (value,
217           gst_alsa_find_card_name (GST_OBJECT_CAST (src),
218               src->device, SND_PCM_STREAM_CAPTURE));
219       break;
220     default:
221       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
222       break;
223   }
224 }
225 
226 static GstStateChangeReturn
gst_alsasrc_change_state(GstElement * element,GstStateChange transition)227 gst_alsasrc_change_state (GstElement * element, GstStateChange transition)
228 {
229   GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
230   GstAlsaSrc *alsa = GST_ALSA_SRC (element);
231   GstClock *clk;
232 
233   switch (transition) {
234       /* show the compiler that we care */
235     case GST_STATE_CHANGE_NULL_TO_READY:
236     case GST_STATE_CHANGE_READY_TO_PAUSED:
237     case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
238     case GST_STATE_CHANGE_PAUSED_TO_READY:
239     case GST_STATE_CHANGE_READY_TO_NULL:
240     case GST_STATE_CHANGE_NULL_TO_NULL:
241     case GST_STATE_CHANGE_READY_TO_READY:
242     case GST_STATE_CHANGE_PAUSED_TO_PAUSED:
243     case GST_STATE_CHANGE_PLAYING_TO_PLAYING:
244       break;
245     case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
246       alsa->driver_timestamps = FALSE;
247 
248       clk = gst_element_get_clock (element);
249       if (clk != NULL) {
250         if (GST_IS_SYSTEM_CLOCK (clk)) {
251           gint clocktype;
252           g_object_get (clk, "clock-type", &clocktype, NULL);
253           if (clocktype == GST_CLOCK_TYPE_MONOTONIC) {
254             GST_INFO ("Using driver timestamps !");
255             alsa->driver_timestamps = TRUE;
256           }
257         }
258 
259         gst_object_unref (clk);
260       }
261       break;
262   }
263   ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
264 
265   return ret;
266 }
267 
268 static void
gst_alsasrc_init(GstAlsaSrc * alsasrc)269 gst_alsasrc_init (GstAlsaSrc * alsasrc)
270 {
271   GST_DEBUG_OBJECT (alsasrc, "initializing");
272 
273   alsasrc->device = g_strdup (DEFAULT_PROP_DEVICE);
274   alsasrc->cached_caps = NULL;
275   alsasrc->driver_timestamps = FALSE;
276 
277   g_mutex_init (&alsasrc->alsa_lock);
278 }
279 
280 #define CHECK(call, error) \
281 G_STMT_START {                  \
282 if ((err = call) < 0)           \
283   goto error;                   \
284 } G_STMT_END;
285 
286 
287 static GstCaps *
gst_alsasrc_getcaps(GstBaseSrc * bsrc,GstCaps * filter)288 gst_alsasrc_getcaps (GstBaseSrc * bsrc, GstCaps * filter)
289 {
290   GstElementClass *element_class;
291   GstPadTemplate *pad_template;
292   GstAlsaSrc *src;
293   GstCaps *caps, *templ_caps;
294 
295   src = GST_ALSA_SRC (bsrc);
296 
297   if (src->handle == NULL) {
298     GST_DEBUG_OBJECT (src, "device not open, using template caps");
299     return GST_BASE_SRC_CLASS (parent_class)->get_caps (bsrc, filter);
300   }
301 
302   if (src->cached_caps) {
303     GST_LOG_OBJECT (src, "Returning cached caps");
304     if (filter)
305       return gst_caps_intersect_full (filter, src->cached_caps,
306           GST_CAPS_INTERSECT_FIRST);
307     else
308       return gst_caps_ref (src->cached_caps);
309   }
310 
311   element_class = GST_ELEMENT_GET_CLASS (src);
312   pad_template = gst_element_class_get_pad_template (element_class, "src");
313   g_return_val_if_fail (pad_template != NULL, NULL);
314 
315   templ_caps = gst_pad_template_get_caps (pad_template);
316   GST_INFO_OBJECT (src, "template caps %" GST_PTR_FORMAT, templ_caps);
317 
318   caps = gst_alsa_probe_supported_formats (GST_OBJECT (src),
319       src->device, src->handle, templ_caps);
320   gst_caps_unref (templ_caps);
321 
322   if (caps) {
323     src->cached_caps = gst_caps_ref (caps);
324   }
325 
326   GST_INFO_OBJECT (src, "returning caps %" GST_PTR_FORMAT, caps);
327 
328   if (filter) {
329     GstCaps *intersection;
330 
331     intersection =
332         gst_caps_intersect_full (filter, caps, GST_CAPS_INTERSECT_FIRST);
333     gst_caps_unref (caps);
334     return intersection;
335   } else {
336     return caps;
337   }
338 }
339 
340 static int
set_hwparams(GstAlsaSrc * alsa)341 set_hwparams (GstAlsaSrc * alsa)
342 {
343   guint rrate;
344   gint err;
345   snd_pcm_hw_params_t *params;
346 
347   snd_pcm_hw_params_malloc (&params);
348 
349   /* choose all parameters */
350   CHECK (snd_pcm_hw_params_any (alsa->handle, params), no_config);
351   /* set the interleaved read/write format */
352   CHECK (snd_pcm_hw_params_set_access (alsa->handle, params, alsa->access),
353       wrong_access);
354   /* set the sample format */
355   CHECK (snd_pcm_hw_params_set_format (alsa->handle, params, alsa->format),
356       no_sample_format);
357   /* set the count of channels */
358   CHECK (snd_pcm_hw_params_set_channels (alsa->handle, params, alsa->channels),
359       no_channels);
360   /* set the stream rate */
361   rrate = alsa->rate;
362   CHECK (snd_pcm_hw_params_set_rate_near (alsa->handle, params, &rrate, NULL),
363       no_rate);
364   if (rrate != alsa->rate)
365     goto rate_match;
366 
367 #ifndef GST_DISABLE_GST_DEBUG
368   /* get and dump some limits */
369   {
370     guint min, max;
371 
372     snd_pcm_hw_params_get_buffer_time_min (params, &min, NULL);
373     snd_pcm_hw_params_get_buffer_time_max (params, &max, NULL);
374 
375     GST_DEBUG_OBJECT (alsa, "buffer time %u, min %u, max %u",
376         alsa->buffer_time, min, max);
377 
378     snd_pcm_hw_params_get_period_time_min (params, &min, NULL);
379     snd_pcm_hw_params_get_period_time_max (params, &max, NULL);
380 
381     GST_DEBUG_OBJECT (alsa, "period time %u, min %u, max %u",
382         alsa->period_time, min, max);
383 
384     snd_pcm_hw_params_get_periods_min (params, &min, NULL);
385     snd_pcm_hw_params_get_periods_max (params, &max, NULL);
386 
387     GST_DEBUG_OBJECT (alsa, "periods min %u, max %u", min, max);
388   }
389 #endif
390 
391   if (alsa->buffer_time != -1) {
392     /* set the buffer time */
393     CHECK (snd_pcm_hw_params_set_buffer_time_near (alsa->handle, params,
394             &alsa->buffer_time, NULL), buffer_time);
395     GST_DEBUG_OBJECT (alsa, "buffer time %u", alsa->buffer_time);
396   }
397   if (alsa->period_time != -1) {
398     /* set the period time */
399     CHECK (snd_pcm_hw_params_set_period_time_near (alsa->handle, params,
400             &alsa->period_time, NULL), period_time);
401     GST_DEBUG_OBJECT (alsa, "period time %u", alsa->period_time);
402   }
403 
404   /* write the parameters to device */
405   CHECK (snd_pcm_hw_params (alsa->handle, params), set_hw_params);
406 
407   CHECK (snd_pcm_hw_params_get_buffer_size (params, &alsa->buffer_size),
408       buffer_size);
409 
410   CHECK (snd_pcm_hw_params_get_period_size (params, &alsa->period_size, NULL),
411       period_size);
412 
413   snd_pcm_hw_params_free (params);
414   return 0;
415 
416   /* ERRORS */
417 no_config:
418   {
419     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
420         ("Broken configuration for recording: no configurations available: %s",
421             snd_strerror (err)));
422     snd_pcm_hw_params_free (params);
423     return err;
424   }
425 wrong_access:
426   {
427     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
428         ("Access type not available for recording: %s", snd_strerror (err)));
429     snd_pcm_hw_params_free (params);
430     return err;
431   }
432 no_sample_format:
433   {
434     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
435         ("Sample format not available for recording: %s", snd_strerror (err)));
436     snd_pcm_hw_params_free (params);
437     return err;
438   }
439 no_channels:
440   {
441     gchar *msg = NULL;
442 
443     if ((alsa->channels) == 1)
444       msg = g_strdup (_("Could not open device for recording in mono mode."));
445     if ((alsa->channels) == 2)
446       msg = g_strdup (_("Could not open device for recording in stereo mode."));
447     if ((alsa->channels) > 2)
448       msg =
449           g_strdup_printf (_
450           ("Could not open device for recording in %d-channel mode"),
451           alsa->channels);
452     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, ("%s", msg),
453         ("%s", snd_strerror (err)));
454     g_free (msg);
455     snd_pcm_hw_params_free (params);
456     return err;
457   }
458 no_rate:
459   {
460     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
461         ("Rate %iHz not available for recording: %s",
462             alsa->rate, snd_strerror (err)));
463     snd_pcm_hw_params_free (params);
464     return err;
465   }
466 rate_match:
467   {
468     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
469         ("Rate doesn't match (requested %iHz, get %iHz)", alsa->rate, err));
470     snd_pcm_hw_params_free (params);
471     return -EINVAL;
472   }
473 buffer_time:
474   {
475     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
476         ("Unable to set buffer time %i for recording: %s",
477             alsa->buffer_time, snd_strerror (err)));
478     snd_pcm_hw_params_free (params);
479     return err;
480   }
481 buffer_size:
482   {
483     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
484         ("Unable to get buffer size for recording: %s", snd_strerror (err)));
485     snd_pcm_hw_params_free (params);
486     return err;
487   }
488 period_time:
489   {
490     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
491         ("Unable to set period time %i for recording: %s", alsa->period_time,
492             snd_strerror (err)));
493     snd_pcm_hw_params_free (params);
494     return err;
495   }
496 period_size:
497   {
498     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
499         ("Unable to get period size for recording: %s", snd_strerror (err)));
500     snd_pcm_hw_params_free (params);
501     return err;
502   }
503 set_hw_params:
504   {
505     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
506         ("Unable to set hw params for recording: %s", snd_strerror (err)));
507     snd_pcm_hw_params_free (params);
508     return err;
509   }
510 }
511 
512 static int
set_swparams(GstAlsaSrc * alsa)513 set_swparams (GstAlsaSrc * alsa)
514 {
515   int err;
516   snd_pcm_sw_params_t *params;
517 
518   snd_pcm_sw_params_malloc (&params);
519 
520   /* get the current swparams */
521   CHECK (snd_pcm_sw_params_current (alsa->handle, params), no_config);
522   /* allow the transfer when at least period_size samples can be processed */
523   CHECK (snd_pcm_sw_params_set_avail_min (alsa->handle, params,
524           alsa->period_size), set_avail);
525   /* start the transfer on first read */
526   CHECK (snd_pcm_sw_params_set_start_threshold (alsa->handle, params,
527           0), start_threshold);
528   /* use monotonic timestamping */
529   CHECK (snd_pcm_sw_params_set_tstamp_mode (alsa->handle, params,
530           SND_PCM_TSTAMP_MMAP), tstamp_mode);
531 
532 #if GST_CHECK_ALSA_VERSION(1,0,16)
533   /* snd_pcm_sw_params_set_xfer_align() is deprecated, alignment is always 1 */
534 #else
535   /* align all transfers to 1 sample */
536   CHECK (snd_pcm_sw_params_set_xfer_align (alsa->handle, params, 1), set_align);
537 #endif
538 
539   /* write the parameters to the recording device */
540   CHECK (snd_pcm_sw_params (alsa->handle, params), set_sw_params);
541 
542   snd_pcm_sw_params_free (params);
543   return 0;
544 
545   /* ERRORS */
546 no_config:
547   {
548     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
549         ("Unable to determine current swparams for playback: %s",
550             snd_strerror (err)));
551     snd_pcm_sw_params_free (params);
552     return err;
553   }
554 start_threshold:
555   {
556     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
557         ("Unable to set start threshold mode for playback: %s",
558             snd_strerror (err)));
559     snd_pcm_sw_params_free (params);
560     return err;
561   }
562 set_avail:
563   {
564     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
565         ("Unable to set avail min for playback: %s", snd_strerror (err)));
566     snd_pcm_sw_params_free (params);
567     return err;
568   }
569 tstamp_mode:
570   {
571     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
572         ("Unable to set tstamp mode for playback: %s", snd_strerror (err)));
573     snd_pcm_sw_params_free (params);
574     return err;
575   }
576 #if !GST_CHECK_ALSA_VERSION(1,0,16)
577 set_align:
578   {
579     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
580         ("Unable to set transfer align for playback: %s", snd_strerror (err)));
581     snd_pcm_sw_params_free (params);
582     return err;
583   }
584 #endif
585 set_sw_params:
586   {
587     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
588         ("Unable to set sw params for playback: %s", snd_strerror (err)));
589     snd_pcm_sw_params_free (params);
590     return err;
591   }
592 }
593 
594 static gboolean
alsasrc_parse_spec(GstAlsaSrc * alsa,GstAudioRingBufferSpec * spec)595 alsasrc_parse_spec (GstAlsaSrc * alsa, GstAudioRingBufferSpec * spec)
596 {
597   switch (spec->type) {
598     case GST_AUDIO_RING_BUFFER_FORMAT_TYPE_RAW:
599       switch (GST_AUDIO_INFO_FORMAT (&spec->info)) {
600         case GST_AUDIO_FORMAT_U8:
601           alsa->format = SND_PCM_FORMAT_U8;
602           break;
603         case GST_AUDIO_FORMAT_S8:
604           alsa->format = SND_PCM_FORMAT_S8;
605           break;
606         case GST_AUDIO_FORMAT_S16LE:
607           alsa->format = SND_PCM_FORMAT_S16_LE;
608           break;
609         case GST_AUDIO_FORMAT_S16BE:
610           alsa->format = SND_PCM_FORMAT_S16_BE;
611           break;
612         case GST_AUDIO_FORMAT_U16LE:
613           alsa->format = SND_PCM_FORMAT_U16_LE;
614           break;
615         case GST_AUDIO_FORMAT_U16BE:
616           alsa->format = SND_PCM_FORMAT_U16_BE;
617           break;
618         case GST_AUDIO_FORMAT_S24_32LE:
619           alsa->format = SND_PCM_FORMAT_S24_LE;
620           break;
621         case GST_AUDIO_FORMAT_S24_32BE:
622           alsa->format = SND_PCM_FORMAT_S24_BE;
623           break;
624         case GST_AUDIO_FORMAT_U24_32LE:
625           alsa->format = SND_PCM_FORMAT_U24_LE;
626           break;
627         case GST_AUDIO_FORMAT_U24_32BE:
628           alsa->format = SND_PCM_FORMAT_U24_BE;
629           break;
630         case GST_AUDIO_FORMAT_S32LE:
631           alsa->format = SND_PCM_FORMAT_S32_LE;
632           break;
633         case GST_AUDIO_FORMAT_S32BE:
634           alsa->format = SND_PCM_FORMAT_S32_BE;
635           break;
636         case GST_AUDIO_FORMAT_U32LE:
637           alsa->format = SND_PCM_FORMAT_U32_LE;
638           break;
639         case GST_AUDIO_FORMAT_U32BE:
640           alsa->format = SND_PCM_FORMAT_U32_BE;
641           break;
642         case GST_AUDIO_FORMAT_S24LE:
643           alsa->format = SND_PCM_FORMAT_S24_3LE;
644           break;
645         case GST_AUDIO_FORMAT_S24BE:
646           alsa->format = SND_PCM_FORMAT_S24_3BE;
647           break;
648         case GST_AUDIO_FORMAT_U24LE:
649           alsa->format = SND_PCM_FORMAT_U24_3LE;
650           break;
651         case GST_AUDIO_FORMAT_U24BE:
652           alsa->format = SND_PCM_FORMAT_U24_3BE;
653           break;
654         case GST_AUDIO_FORMAT_S20LE:
655           alsa->format = SND_PCM_FORMAT_S20_3LE;
656           break;
657         case GST_AUDIO_FORMAT_S20BE:
658           alsa->format = SND_PCM_FORMAT_S20_3BE;
659           break;
660         case GST_AUDIO_FORMAT_U20LE:
661           alsa->format = SND_PCM_FORMAT_U20_3LE;
662           break;
663         case GST_AUDIO_FORMAT_U20BE:
664           alsa->format = SND_PCM_FORMAT_U20_3BE;
665           break;
666         case GST_AUDIO_FORMAT_S18LE:
667           alsa->format = SND_PCM_FORMAT_S18_3LE;
668           break;
669         case GST_AUDIO_FORMAT_S18BE:
670           alsa->format = SND_PCM_FORMAT_S18_3BE;
671           break;
672         case GST_AUDIO_FORMAT_U18LE:
673           alsa->format = SND_PCM_FORMAT_U18_3LE;
674           break;
675         case GST_AUDIO_FORMAT_U18BE:
676           alsa->format = SND_PCM_FORMAT_U18_3BE;
677           break;
678         case GST_AUDIO_FORMAT_F32LE:
679           alsa->format = SND_PCM_FORMAT_FLOAT_LE;
680           break;
681         case GST_AUDIO_FORMAT_F32BE:
682           alsa->format = SND_PCM_FORMAT_FLOAT_BE;
683           break;
684         case GST_AUDIO_FORMAT_F64LE:
685           alsa->format = SND_PCM_FORMAT_FLOAT64_LE;
686           break;
687         case GST_AUDIO_FORMAT_F64BE:
688           alsa->format = SND_PCM_FORMAT_FLOAT64_BE;
689           break;
690         default:
691           goto error;
692       }
693       break;
694     case GST_AUDIO_RING_BUFFER_FORMAT_TYPE_A_LAW:
695       alsa->format = SND_PCM_FORMAT_A_LAW;
696       break;
697     case GST_AUDIO_RING_BUFFER_FORMAT_TYPE_MU_LAW:
698       alsa->format = SND_PCM_FORMAT_MU_LAW;
699       break;
700     default:
701       goto error;
702 
703   }
704   alsa->rate = GST_AUDIO_INFO_RATE (&spec->info);
705   alsa->channels = GST_AUDIO_INFO_CHANNELS (&spec->info);
706   alsa->buffer_time = spec->buffer_time;
707   alsa->period_time = spec->latency_time;
708   alsa->access = SND_PCM_ACCESS_RW_INTERLEAVED;
709 
710   if (spec->type == GST_AUDIO_RING_BUFFER_FORMAT_TYPE_RAW && alsa->channels < 9)
711     gst_audio_ring_buffer_set_channel_positions (GST_AUDIO_BASE_SRC
712         (alsa)->ringbuffer, alsa_position[alsa->channels - 1]);
713 
714   return TRUE;
715 
716   /* ERRORS */
717 error:
718   {
719     return FALSE;
720   }
721 }
722 
723 static gboolean
gst_alsasrc_open(GstAudioSrc * asrc)724 gst_alsasrc_open (GstAudioSrc * asrc)
725 {
726   GstAlsaSrc *alsa;
727   gint err;
728 
729   alsa = GST_ALSA_SRC (asrc);
730 
731   CHECK (snd_pcm_open (&alsa->handle, alsa->device, SND_PCM_STREAM_CAPTURE,
732           (alsa->driver_timestamps) ? 0 : SND_PCM_NONBLOCK), open_error);
733 
734   return TRUE;
735 
736   /* ERRORS */
737 open_error:
738   {
739     if (err == -EBUSY) {
740       GST_ELEMENT_ERROR (alsa, RESOURCE, BUSY,
741           (_("Could not open audio device for recording. "
742                   "Device is being used by another application.")),
743           ("Device '%s' is busy", alsa->device));
744     } else {
745       GST_ELEMENT_ERROR (alsa, RESOURCE, OPEN_READ,
746           (_("Could not open audio device for recording.")),
747           ("Recording open error on device '%s': %s", alsa->device,
748               snd_strerror (err)));
749     }
750     return FALSE;
751   }
752 }
753 
754 static gboolean
gst_alsasrc_prepare(GstAudioSrc * asrc,GstAudioRingBufferSpec * spec)755 gst_alsasrc_prepare (GstAudioSrc * asrc, GstAudioRingBufferSpec * spec)
756 {
757   GstAlsaSrc *alsa;
758   gint err;
759 
760   alsa = GST_ALSA_SRC (asrc);
761 
762   if (!alsasrc_parse_spec (alsa, spec))
763     goto spec_parse;
764 
765   CHECK (snd_pcm_nonblock (alsa->handle, 0), non_block);
766 
767   CHECK (set_hwparams (alsa), hw_params_failed);
768   CHECK (set_swparams (alsa), sw_params_failed);
769   CHECK (snd_pcm_prepare (alsa->handle), prepare_failed);
770 
771   alsa->bpf = GST_AUDIO_INFO_BPF (&spec->info);
772   spec->segsize = alsa->period_size * alsa->bpf;
773   spec->segtotal = alsa->buffer_size / alsa->period_size;
774 
775   {
776     snd_output_t *out_buf = NULL;
777     char *msg = NULL;
778 
779     snd_output_buffer_open (&out_buf);
780     snd_pcm_dump_hw_setup (alsa->handle, out_buf);
781     snd_output_buffer_string (out_buf, &msg);
782     GST_DEBUG_OBJECT (alsa, "Hardware setup: \n%s", msg);
783     snd_output_close (out_buf);
784     snd_output_buffer_open (&out_buf);
785     snd_pcm_dump_sw_setup (alsa->handle, out_buf);
786     snd_output_buffer_string (out_buf, &msg);
787     GST_DEBUG_OBJECT (alsa, "Software setup: \n%s", msg);
788     snd_output_close (out_buf);
789   }
790 
791 #ifdef SND_CHMAP_API_VERSION
792   alsa_detect_channels_mapping (GST_OBJECT (alsa), alsa->handle, spec,
793       alsa->channels, GST_AUDIO_BASE_SRC (alsa)->ringbuffer);
794 #endif /* SND_CHMAP_API_VERSION */
795 
796   return TRUE;
797 
798   /* ERRORS */
799 spec_parse:
800   {
801     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
802         ("Error parsing spec"));
803     return FALSE;
804   }
805 non_block:
806   {
807     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
808         ("Could not set device to blocking: %s", snd_strerror (err)));
809     return FALSE;
810   }
811 hw_params_failed:
812   {
813     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
814         ("Setting of hwparams failed: %s", snd_strerror (err)));
815     return FALSE;
816   }
817 sw_params_failed:
818   {
819     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
820         ("Setting of swparams failed: %s", snd_strerror (err)));
821     return FALSE;
822   }
823 prepare_failed:
824   {
825     GST_ELEMENT_ERROR (alsa, RESOURCE, SETTINGS, (NULL),
826         ("Prepare failed: %s", snd_strerror (err)));
827     return FALSE;
828   }
829 }
830 
831 static gboolean
gst_alsasrc_unprepare(GstAudioSrc * asrc)832 gst_alsasrc_unprepare (GstAudioSrc * asrc)
833 {
834   GstAlsaSrc *alsa;
835 
836   alsa = GST_ALSA_SRC (asrc);
837 
838   snd_pcm_drop (alsa->handle);
839   snd_pcm_hw_free (alsa->handle);
840   snd_pcm_nonblock (alsa->handle, 1);
841 
842   return TRUE;
843 }
844 
845 static gboolean
gst_alsasrc_close(GstAudioSrc * asrc)846 gst_alsasrc_close (GstAudioSrc * asrc)
847 {
848   GstAlsaSrc *alsa = GST_ALSA_SRC (asrc);
849 
850   snd_pcm_close (alsa->handle);
851   alsa->handle = NULL;
852 
853   gst_caps_replace (&alsa->cached_caps, NULL);
854 
855   return TRUE;
856 }
857 
858 /*
859  *   Underrun and suspend recovery
860  */
861 static gint
xrun_recovery(GstAlsaSrc * alsa,snd_pcm_t * handle,gint err)862 xrun_recovery (GstAlsaSrc * alsa, snd_pcm_t * handle, gint err)
863 {
864   GST_WARNING_OBJECT (alsa, "xrun recovery %d: %s", err, g_strerror (-err));
865 
866   if (err == -EPIPE) {          /* under-run */
867     err = snd_pcm_prepare (handle);
868     if (err < 0)
869       GST_WARNING_OBJECT (alsa,
870           "Can't recover from underrun, prepare failed: %s",
871           snd_strerror (err));
872     return 0;
873   } else if (err == -ESTRPIPE) {
874     while ((err = snd_pcm_resume (handle)) == -EAGAIN)
875       g_usleep (100);           /* wait until the suspend flag is released */
876 
877     if (err < 0) {
878       err = snd_pcm_prepare (handle);
879       if (err < 0)
880         GST_WARNING_OBJECT (alsa,
881             "Can't recover from suspend, prepare failed: %s",
882             snd_strerror (err));
883     }
884     return 0;
885   }
886   return err;
887 }
888 
889 static GstClockTime
gst_alsasrc_get_timestamp(GstAlsaSrc * asrc)890 gst_alsasrc_get_timestamp (GstAlsaSrc * asrc)
891 {
892   snd_pcm_status_t *status;
893   snd_htimestamp_t tstamp;
894   GstClockTime timestamp;
895   snd_pcm_uframes_t avail;
896   gint err = -EPIPE;
897 
898   if (G_UNLIKELY (!asrc)) {
899     GST_ERROR_OBJECT (asrc, "No alsa handle created yet !");
900     return GST_CLOCK_TIME_NONE;
901   }
902 
903   if (G_UNLIKELY (snd_pcm_status_malloc (&status) != 0)) {
904     GST_ERROR_OBJECT (asrc, "snd_pcm_status_malloc failed");
905     return GST_CLOCK_TIME_NONE;
906   }
907 
908   if (G_UNLIKELY (snd_pcm_status (asrc->handle, status) != 0)) {
909     GST_ERROR_OBJECT (asrc, "snd_pcm_status failed");
910     return GST_CLOCK_TIME_NONE;
911   }
912 
913   /* in case an xrun condition has occured we need to handle this */
914   if (snd_pcm_status_get_state (status) != SND_PCM_STATE_RUNNING) {
915     if (xrun_recovery (asrc, asrc->handle, err) < 0) {
916       GST_WARNING_OBJECT (asrc, "Could not recover from xrun condition !");
917     }
918     /* reload the status alsa status object, since recovery made it invalid */
919     if (G_UNLIKELY (snd_pcm_status (asrc->handle, status) != 0)) {
920       GST_ERROR_OBJECT (asrc, "snd_pcm_status failed");
921     }
922   }
923 
924   /* get high resolution time stamp from driver */
925   snd_pcm_status_get_htstamp (status, &tstamp);
926 
927   if (tstamp.tv_sec == 0 && tstamp.tv_nsec == 0)
928     return GST_CLOCK_TIME_NONE;
929 
930   timestamp = GST_TIMESPEC_TO_TIME (tstamp);
931 
932   /* max available frames sets the depth of the buffer */
933   avail = snd_pcm_status_get_avail (status);
934 
935   /* calculate the timestamp of the next sample to be read */
936   timestamp -= gst_util_uint64_scale_int (avail, GST_SECOND, asrc->rate);
937 
938   /* compensate for the fact that we really need the timestamp of the
939    * previously read data segment */
940   timestamp -= asrc->period_time * 1000;
941 
942   snd_pcm_status_free (status);
943 
944   GST_LOG_OBJECT (asrc, "ALSA timestamp : %" GST_TIME_FORMAT
945       ", delay %lu", GST_TIME_ARGS (timestamp), avail);
946 
947   return timestamp;
948 }
949 
950 static guint
gst_alsasrc_read(GstAudioSrc * asrc,gpointer data,guint length,GstClockTime * timestamp)951 gst_alsasrc_read (GstAudioSrc * asrc, gpointer data, guint length,
952     GstClockTime * timestamp)
953 {
954   GstAlsaSrc *alsa;
955   gint err;
956   gint cptr;
957   guint8 *ptr = data;
958 
959   alsa = GST_ALSA_SRC (asrc);
960 
961   cptr = length / alsa->bpf;
962 
963   GST_ALSA_SRC_LOCK (asrc);
964   while (cptr > 0) {
965     if ((err = snd_pcm_readi (alsa->handle, ptr, cptr)) < 0) {
966       if (err == -EAGAIN) {
967         GST_DEBUG_OBJECT (asrc, "Read error: %s", snd_strerror (err));
968         continue;
969       } else if (err == -ENODEV) {
970         goto device_disappeared;
971       } else if (xrun_recovery (alsa, alsa->handle, err) < 0) {
972         goto read_error;
973       }
974       continue;
975     }
976 
977     ptr += snd_pcm_frames_to_bytes (alsa->handle, err);
978     cptr -= err;
979   }
980   GST_ALSA_SRC_UNLOCK (asrc);
981 
982   /* if driver timestamps are enabled we need to return this here */
983   if (alsa->driver_timestamps && timestamp)
984     *timestamp = gst_alsasrc_get_timestamp (alsa);
985 
986   return length - (cptr * alsa->bpf);
987 
988 read_error:
989   {
990     GST_ALSA_SRC_UNLOCK (asrc);
991     return length;              /* skip one period */
992   }
993 device_disappeared:
994   {
995     GST_ELEMENT_ERROR (asrc, RESOURCE, READ,
996         (_("Error recording from audio device. "
997                 "The device has been disconnected.")), (NULL));
998     GST_ALSA_SRC_UNLOCK (asrc);
999     return (guint) - 1;
1000   }
1001 }
1002 
1003 static guint
gst_alsasrc_delay(GstAudioSrc * asrc)1004 gst_alsasrc_delay (GstAudioSrc * asrc)
1005 {
1006   GstAlsaSrc *alsa;
1007   snd_pcm_sframes_t delay;
1008   int res;
1009 
1010   alsa = GST_ALSA_SRC (asrc);
1011 
1012   res = snd_pcm_delay (alsa->handle, &delay);
1013   if (G_UNLIKELY (res < 0)) {
1014     GST_DEBUG_OBJECT (alsa, "snd_pcm_delay returned %d", res);
1015     delay = 0;
1016   }
1017 
1018   return CLAMP (delay, 0, alsa->buffer_size);
1019 }
1020 
1021 static void
gst_alsasrc_reset(GstAudioSrc * asrc)1022 gst_alsasrc_reset (GstAudioSrc * asrc)
1023 {
1024   GstAlsaSrc *alsa;
1025   gint err;
1026 
1027   alsa = GST_ALSA_SRC (asrc);
1028 
1029   GST_ALSA_SRC_LOCK (asrc);
1030   GST_DEBUG_OBJECT (alsa, "drop");
1031   CHECK (snd_pcm_drop (alsa->handle), drop_error);
1032   GST_DEBUG_OBJECT (alsa, "prepare");
1033   CHECK (snd_pcm_prepare (alsa->handle), prepare_error);
1034   GST_DEBUG_OBJECT (alsa, "reset done");
1035   GST_ALSA_SRC_UNLOCK (asrc);
1036 
1037   return;
1038 
1039   /* ERRORS */
1040 drop_error:
1041   {
1042     GST_ERROR_OBJECT (alsa, "alsa-reset: pcm drop error: %s",
1043         snd_strerror (err));
1044     GST_ALSA_SRC_UNLOCK (asrc);
1045     return;
1046   }
1047 prepare_error:
1048   {
1049     GST_ERROR_OBJECT (alsa, "alsa-reset: pcm prepare error: %s",
1050         snd_strerror (err));
1051     GST_ALSA_SRC_UNLOCK (asrc);
1052     return;
1053   }
1054 }
1055