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gstreamer/ext/alsa/gstalsa.c
Leif Johnson 20a9403fbf + alsasrc compiles and runs in "alsasrc ! fakesink" and "alsasrc ! osssink" pipelines. seems to have a 100% cpu issue... 
Original commit message from CVS:
+ alsasrc compiles and runs in "alsasrc ! fakesink" and "alsasrc ! osssink"
pipelines. seems to have a 100% cpu issue at the moment.
2003-02-27 23:13:22 +00:00

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/*
* Copyright (C) 2001 CodeFactory AB
* Copyright (C) 2001 Thomas Nyberg <thomas@codefactory.se>
* Copyright (C) 2001-2002 Andy Wingo <apwingo@eos.ncsu.edu>
* Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
*
* This library 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 library 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 library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdlib.h>
#include <sys/time.h>
#include "gstalsa.h"
/* error checking for standard alsa functions */
#ifdef G_HAVE_ISO_VARARGS
#define ERROR_CHECK(value, ...) G_STMT_START{ \
int err = (value); \
if (err < 0) { \
g_warning ( __VA_ARGS__, snd_strerror (err)); \
return FALSE; \
} \
}G_STMT_END
#elif defined(G_HAVE_GNUC_VARARGS)
#define ERROR_CHECK(value, args...) G_STMT_START{ \
int err = (value); \
if (err < 0) { \
g_warning ( ## args, snd_strerror (err)); \
return FALSE; \
} \
}G_STMT_END
#else
#define ERROR_CHECK(value, args...) G_STMT_START{ \
int err = (value); \
if (err < 0) { \
g_warning (snd_strerror (err)); \
return FALSE; \
} \
}G_STMT_END
#endif
/* elementfactory information */
static GstElementDetails gst_alsa_sink_details = {
"Alsa Sink",
"Sink/Audio",
"LGPL",
"Output to a sound card via ALSA",
VERSION,
"Thomas Nyberg <thomas@codefactory.se>, "
"Andy Wingo <apwingo@eos.ncsu.edu>"
"Benjamin Otte <in7y118@public.uni-hamburg.de>",
"(C) 2001-2003"
};
/* elementfactory information */
static GstElementDetails gst_alsa_src_details = {
"Alsa Src",
"Source/Audio",
"LGPL",
"Read from a sound card via ALSA",
VERSION,
"Thomas Nyberg <thomas@codefactory.se>, "
"Andy Wingo <apwingo@eos.ncsu.edu>"
"Benjamin Otte <in7y118@public.uni-hamburg.de>",
"(C) 2001-2003"
};
/* GObject functions */
static void gst_alsa_class_init (GstAlsaClass *klass);
static void gst_alsa_init (GstAlsa *this);
static void gst_alsa_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);
static void gst_alsa_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec);
/* GStreamer functions for pads and state changing */
static GstPadTemplate *gst_alsa_src_pad_factory ();
static GstPadTemplate *gst_alsa_src_request_pad_factory ();
static GstPadTemplate *gst_alsa_sink_pad_factory ();
static GstPadTemplate *gst_alsa_sink_request_pad_factory ();
static GstPad *gst_alsa_request_new_pad (GstElement *element, GstPadTemplate *templ, const gchar *name);
static GstPadLinkReturn gst_alsa_link (GstPad *pad, GstCaps *caps);
static GstCaps *gst_alsa_caps (snd_pcm_format_t format, gint rate, gint channels);
static GstBufferPool *gst_alsa_src_get_buffer_pool (GstPad *pad);
static GstElementStateReturn gst_alsa_change_state (GstElement *element);
/* audio processing functions */
static int gst_alsa_do_mmap (GstAlsa *this, guint numpads, snd_pcm_sframes_t *avail);
static void gst_alsa_sink_loop (GstElement *element);
static void gst_alsa_src_loop (GstElement *element);
static void gst_alsa_xrun_recovery (GstAlsa *this);
static gboolean gst_alsa_sink_check_event (GstAlsa *this, gint pad_nr);
/* alsa setup / start / stop functions */
static gboolean gst_alsa_set_hw_params (GstAlsa *this);
static gboolean gst_alsa_set_sw_params (GstAlsa *this);
static gboolean gst_alsa_open_audio (GstAlsa *this);
static gboolean gst_alsa_start_audio (GstAlsa *this);
static gboolean gst_alsa_drain_audio (GstAlsa *this);
static gboolean gst_alsa_stop_audio (GstAlsa *this);
static gboolean gst_alsa_close_audio (GstAlsa *this);
/*** TYPE FUNCTIONS ***********************************************************/
#define GST_TYPE_ALSA_FORMAT (gst_alsa_format_get_type())
static GType
gst_alsa_format_get_type (void)
{
static GType type = 0;
static GEnumValue *values = NULL;
gint i;
if (values == NULL) {
/* the three: for -1, 0, and the terminating NULL */
values = g_new0 (GEnumValue, SND_PCM_FORMAT_LAST + 1);
for (i = -1; i <= SND_PCM_FORMAT_LAST; i++) {
values[i + 1].value = i; /* UNKNOWN is -1 */
values[i + 1].value_name = g_strdup_printf ("%d", i);
values[i + 1].value_nick = g_strdup (snd_pcm_format_name ((snd_pcm_format_t) i));
}
}
if (!type)
type = g_enum_register_static ("GstAlsaFormat", values);
return type;
}
GType
gst_alsa_get_type (void)
{
static GType alsa_type = 0;
if (!alsa_type) {
static const GTypeInfo alsa_info = {
sizeof (GstAlsaClass),
NULL,
NULL,
NULL,
NULL,
NULL,
sizeof (GstAlsa),
0,
NULL,
};
alsa_type = g_type_register_static (GST_TYPE_ELEMENT, "GstAlsa", &alsa_info, 0);
}
return alsa_type;
}
GType
gst_alsa_sink_get_type (void)
{
static GType alsa_type = 0;
if (!alsa_type) {
static const GTypeInfo alsa_info = {
sizeof (GstAlsaClass),
NULL,
NULL,
(GClassInitFunc) gst_alsa_class_init,
NULL,
NULL,
sizeof (GstAlsa),
0,
(GInstanceInitFunc) gst_alsa_init,
};
alsa_type = g_type_register_static (GST_TYPE_ALSA, "GstAlsaSink", &alsa_info, 0);
}
return alsa_type;
}
GType
gst_alsa_src_get_type (void)
{
static GType alsa_type = 0;
if (!alsa_type) {
static const GTypeInfo alsa_info = {
sizeof (GstAlsaClass),
NULL,
NULL,
(GClassInitFunc) gst_alsa_class_init,
NULL,
NULL,
sizeof (GstAlsa),
0,
(GInstanceInitFunc) gst_alsa_init,
};
alsa_type = g_type_register_static (GST_TYPE_ALSA, "GstAlsaSrc", &alsa_info, 0);
}
return alsa_type;
}
/*** GOBJECT FUNCTIONS ********************************************************/
enum
{
ARG_0,
ARG_DEVICE,
ARG_FORMAT,
ARG_CHANNELS,
ARG_RATE,
ARG_PERIODCOUNT,
ARG_PERIODSIZE,
ARG_BUFFERSIZE,
ARG_DEBUG,
ARG_AUTORECOVER
};
static GstElement *parent_class = NULL;
static void
gst_alsa_class_init (GstAlsaClass *klass)
{
GObjectClass *object_class;
GstElementClass *element_class;
object_class = (GObjectClass *) klass;
element_class = (GstElementClass *) klass;
if (parent_class == NULL)
parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
object_class->get_property = gst_alsa_get_property;
object_class->set_property = gst_alsa_set_property;
g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_DEVICE,
g_param_spec_string ("device", "Device", "Alsa device, as defined in an asoundrc",
"default", G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
/* the next 3 are only settable on srcs */
g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_FORMAT,
g_param_spec_enum ("format", "Format", "PCM audio format",
GST_TYPE_ALSA_FORMAT, -1, G_PARAM_READWRITE));
g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_CHANNELS,
g_param_spec_int ("channels", "Channels", "Number of channels",
1, GST_ALSA_MAX_CHANNELS, 2, G_PARAM_READWRITE));
g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_RATE,
g_param_spec_int ("rate", "Rate", "Sample rate, in Hz",
8000, 192000, 44100, G_PARAM_READWRITE));
g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_PERIODCOUNT,
g_param_spec_int ("period-count", "Period count", "Number of hardware buffers to use",
2, 64, 2, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_PERIODSIZE,
g_param_spec_int ("period-size", "Period size", "Number of frames (samples on each channel) in one hardware period",
64, 8192, 8192, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_BUFFERSIZE,
g_param_spec_int ("buffer-size", "Buffer size", "Number of frames the hardware buffer can hold",
128, 65536, 16384, G_PARAM_READWRITE));
g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_AUTORECOVER,
g_param_spec_boolean ("autorecover", "Automatic xrun recovery", "When TRUE tries to reduce processor load on xruns",
TRUE, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
element_class->change_state = gst_alsa_change_state;
element_class->request_new_pad = gst_alsa_request_new_pad;
}
static void
gst_alsa_init (GstAlsa *this)
{
gint i;
/* init values */
this->handle = NULL;
this->channels = 1;
GST_FLAG_SET (this, GST_ELEMENT_THREAD_SUGGESTED);
if (G_OBJECT_TYPE (this) == GST_TYPE_ALSA_SRC) {
this->stream = SND_PCM_STREAM_CAPTURE;
this->format = SND_PCM_FORMAT_S16; /* native endian */
gst_element_set_loop_function (GST_ELEMENT (this), gst_alsa_src_loop);
this->pads[0].pad = gst_pad_new_from_template (gst_alsa_src_pad_factory (), "src");
gst_pad_set_bufferpool_function(this->pads[0].pad, gst_alsa_src_get_buffer_pool);
/* set the rate to a sensible value. we can't have gobject construct this
manually since it only really makes sense on src elements. the rate can
be changed later through the gobject set property function. */
this->rate = 44100;
} else if (G_OBJECT_TYPE (this) == GST_TYPE_ALSA_SINK) {
this->stream = SND_PCM_STREAM_PLAYBACK;
this->format = SND_PCM_FORMAT_UNKNOWN; /* we don't know until caps are set */
gst_element_set_loop_function (GST_ELEMENT (this), gst_alsa_sink_loop);
this->pads[0].pad = gst_pad_new_from_template (gst_alsa_sink_pad_factory (), "sink");
this->pads[0].bs = gst_bytestream_new (this->pads[0].pad);
}
gst_element_add_pad (GST_ELEMENT (this), this->pads[0].pad);
for (i = 1; i < GST_ALSA_MAX_CHANNELS; i++) {
this->pads[i].pad = NULL;
}
gst_pad_set_link_function (this->pads[0].pad, gst_alsa_link);
}
static void
gst_alsa_set_property (GObject *object, guint prop_id, const GValue *value,
GParamSpec *pspec)
{
GstAlsa *this;
gint buffer_size;
this = (GstAlsa *) object;
switch (prop_id) {
case ARG_DEVICE:
if (this->device)
g_free (this->device);
this->device = g_strdup (g_value_get_string (value));
break;
case ARG_FORMAT:
/* setting this property only makes sense on sources */
if (G_OBJECT_TYPE (this) == GST_TYPE_ALSA_SRC)
this->format = g_value_get_enum (value);
break;
case ARG_CHANNELS:
/* setting this property only makes sense on sources */
if (G_OBJECT_TYPE (this) == GST_TYPE_ALSA_SRC)
this->channels = g_value_get_int (value);
break;
case ARG_RATE:
/* setting this property only makes sense on sources */
if (G_OBJECT_TYPE (this) == GST_TYPE_ALSA_SRC)
this->rate = g_value_get_int (value);
break;
case ARG_PERIODCOUNT:
g_return_if_fail (!GST_FLAG_IS_SET (this, GST_ALSA_RUNNING));
this->period_count = g_value_get_int (value);
break;
case ARG_PERIODSIZE:
g_return_if_fail (!GST_FLAG_IS_SET (this, GST_ALSA_RUNNING));
this->period_size = g_value_get_int (value);
break;
case ARG_BUFFERSIZE:
g_return_if_fail (!GST_FLAG_IS_SET (this, GST_ALSA_RUNNING));
buffer_size = g_value_get_int (value);
this->period_count = buffer_size / this->period_size;
break;
case ARG_AUTORECOVER:
this->autorecover = g_value_get_boolean (value);
return;
default:
GST_DEBUG (0, "Unknown arg");
return;
}
if (GST_STATE (this) == GST_STATE_NULL)
return;
if (GST_FLAG_IS_SET (this, GST_ALSA_RUNNING)) {
gst_alsa_stop_audio (this);
gst_alsa_start_audio (this);
}
}
static void
gst_alsa_get_property (GObject *object, guint prop_id, GValue *value,
GParamSpec *pspec)
{
GstAlsa *this;
this = (GstAlsa *) object;
switch (prop_id) {
case ARG_DEVICE:
g_value_set_string (value, this->device);
break;
case ARG_FORMAT:
g_value_set_enum (value, this->format);
break;
case ARG_CHANNELS:
g_value_set_int (value, this->channels);
break;
case ARG_RATE:
g_value_set_int (value, this->rate);
break;
case ARG_PERIODCOUNT:
g_value_set_int (value, this->period_count);
break;
case ARG_PERIODSIZE:
g_value_set_int (value, this->period_size);
break;
case ARG_BUFFERSIZE:
g_value_set_int (value, this->period_size * this->period_count);
break;
case ARG_AUTORECOVER:
g_value_set_boolean (value, this->autorecover);
break;
default:
GST_DEBUG (0, "Unknown arg");
break;
}
}
/*** GSTREAMER PAD / STATE FUNCTIONS*******************************************/
static GstPadTemplate *
gst_alsa_src_pad_factory (void)
{
static GstPadTemplate *template = NULL;
if (!template)
template = gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
gst_alsa_caps (SND_PCM_FORMAT_UNKNOWN, -1, -1),
NULL);
return template;
}
static GstPadTemplate *
gst_alsa_src_request_pad_factory (void)
{
static GstPadTemplate *template = NULL;
if (!template)
template = gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
gst_alsa_caps (SND_PCM_FORMAT_UNKNOWN, -1, 1),
NULL);
return template;
}
static GstPadTemplate *
gst_alsa_sink_pad_factory (void)
{
static GstPadTemplate *template = NULL;
if (!template)
template = gst_pad_template_new ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
gst_alsa_caps (SND_PCM_FORMAT_UNKNOWN, -1, -1),
NULL);
return template;
}
static GstPadTemplate *
gst_alsa_sink_request_pad_factory (void)
{
static GstPadTemplate *template = NULL;
if (!template)
template =
gst_pad_template_new ("sink%d", GST_PAD_SINK, GST_PAD_REQUEST,
gst_alsa_caps (SND_PCM_FORMAT_UNKNOWN, -1, 1),
NULL);
return template;
}
static GstPad *
gst_alsa_request_new_pad (GstElement *element, GstPadTemplate *templ,
const gchar *name)
{
GstAlsa *this;
gint channel = 0;
g_return_val_if_fail ((this = GST_ALSA (element)), NULL);
g_return_val_if_fail (!GST_FLAG_IS_SET (element, GST_ALSA_RUNNING), NULL);
/* you can't request a pad if the non-request pad already has more than 1 channel */
g_return_val_if_fail (this->channels <= element->numpads, NULL);
if (name) {
/* locate the channel number in the requested pad name. to do so look at
where the % (which begins the %d) is in the template name. */
channel = (gint) strtol (name + (strchr (templ->name_template, '%') -
templ->name_template), NULL, 0);
if (channel < 1 || channel >= GST_ALSA_MAX_CHANNELS) {
g_warning ("invalid channel requested. (%d)", channel);
return NULL;
}
}
/* make sure the requested channel is free. */
if (channel > 0 || this->pads[channel].pad != NULL) {
g_warning ("requested channel %d already in use.", channel);
return NULL;
}
/* if the user doesn't care which channel, find the lowest channel number
that's free. */
if (channel == 0) {
for (channel = 1; channel < GST_ALSA_MAX_CHANNELS; channel++) {
if (this->pads[channel].pad != NULL)
goto found_channel;
}
return NULL;
}
found_channel:
this->pads[channel].pad = gst_pad_new_from_template (templ, name);
gst_pad_set_link_function (this->pads[channel].pad, gst_alsa_link);
gst_element_add_pad (GST_ELEMENT (this), this->pads[channel].pad);
if (G_OBJECT_TYPE (this) == GST_TYPE_ALSA_SINK)
this->pads[channel].bs = gst_bytestream_new (this->pads[channel].pad);
else
gst_pad_set_bufferpool_function(this->pads[channel].pad, gst_alsa_src_get_buffer_pool);
return this->pads[channel].pad;
}
/* gets the matching alsa format or SND_PCM_FORMAT_UNKNOWN if none matches */
static snd_pcm_format_t
gst_alsa_get_format (GstCaps *caps)
{
const gchar *format_name;
/* we have to differentiate between int and float formats */
if (!gst_caps_get_string (caps, "format", &format_name))
return SND_PCM_FORMAT_UNKNOWN;
if (strncmp (format_name, "int", 3) == 0) {
gboolean sign;
gint width, depth, endianness, law;
/* extract the needed information from the caps */
if (!gst_caps_get (caps,
"width", &width,
"depth", &depth,
"law", &law,
"signed", &sign,
NULL))
return SND_PCM_FORMAT_UNKNOWN;
/* extract endianness if needed */
if (width > 8) {
if (!gst_caps_get (caps,
"endianness", &endianness,
NULL))
return SND_PCM_FORMAT_UNKNOWN;
} else {
endianness = G_BYTE_ORDER;
}
/* find corresponding alsa format */
switch (law) {
case 0: return snd_pcm_build_linear_format (depth, width, sign ? 0 : 1, endianness == G_LITTLE_ENDIAN ? 0 : 1);
case 1:
if (width == 8 && depth == 8 && sign == FALSE) {
return SND_PCM_FORMAT_MU_LAW;
} else {
return SND_PCM_FORMAT_UNKNOWN;
}
case 2:
if (width == 8 && depth == 8 && sign == FALSE) {
return SND_PCM_FORMAT_A_LAW;
} else {
return SND_PCM_FORMAT_UNKNOWN;
}
default: return SND_PCM_FORMAT_UNKNOWN;
}
} else if (strncmp (format_name, "float", 5) == 0) {
gchar *layout;
gfloat intercept, slope;
/* get layout */
if (!gst_caps_get (caps, "layout", &layout,
"intercept", &intercept,
"slope", &slope,
NULL))
return SND_PCM_FORMAT_UNKNOWN;
if (intercept != 0.0f || slope != 1.0f) {
return SND_PCM_FORMAT_UNKNOWN;
}
/* match layout to format wrt to endianness */
if (strncmp (layout, "gfloat", 6) == 0) {
if (G_BYTE_ORDER == G_LITTLE_ENDIAN) return SND_PCM_FORMAT_FLOAT_LE;
if (G_BYTE_ORDER == G_BIG_ENDIAN) return SND_PCM_FORMAT_FLOAT_BE;
return SND_PCM_FORMAT_FLOAT;
} else if (strncmp (layout, "gdouble", 7) == 0) {
if (G_BYTE_ORDER == G_LITTLE_ENDIAN) return SND_PCM_FORMAT_FLOAT64_LE;
if (G_BYTE_ORDER == G_BIG_ENDIAN) return SND_PCM_FORMAT_FLOAT64_BE;
return SND_PCM_FORMAT_FLOAT64;
} else {
return SND_PCM_FORMAT_UNKNOWN;
}
}
return SND_PCM_FORMAT_UNKNOWN;
}
/* get props for a spec */
static GstProps *
gst_alsa_get_props (snd_pcm_format_t format)
{
if (format == SND_PCM_FORMAT_A_LAW) {
return gst_props_new ("format", GST_PROPS_STRING ("int"),
"law", GST_PROPS_INT(2),
"width", GST_PROPS_INT(8),
"depth", GST_PROPS_INT(8),
"signed", GST_PROPS_BOOLEAN (FALSE),
NULL);
} else if (format == SND_PCM_FORMAT_MU_LAW) {
return gst_props_new ("format", GST_PROPS_STRING ("int"),
"law", GST_PROPS_INT(1),
"width", GST_PROPS_INT(8),
"depth", GST_PROPS_INT(8),
"signed", GST_PROPS_BOOLEAN (FALSE),
NULL);
} else if (snd_pcm_format_linear (format)) {
/* int */
GstProps *props = gst_props_new ("format", GST_PROPS_STRING ("int"),
"width", GST_PROPS_INT(snd_pcm_format_physical_width (format)),
"depth", GST_PROPS_INT(snd_pcm_format_width (format)),
"law", GST_PROPS_INT(0),
"signed", GST_PROPS_BOOLEAN (snd_pcm_format_signed (format) == 1 ? TRUE : FALSE),
NULL);
/* endianness */
if (snd_pcm_format_physical_width (format) > 8) {
switch (snd_pcm_format_little_endian (format)) {
case 0:
gst_props_add_entry (props, gst_props_entry_new ("endianness", GST_PROPS_INT (G_BIG_ENDIAN)));
break;
case 1:
gst_props_add_entry (props, gst_props_entry_new ("endianness", GST_PROPS_INT (G_LITTLE_ENDIAN)));
break;
default:
g_warning("ALSA: Unknown byte order in sound driver. Continuing by assuming system byte order.");
gst_props_add_entry (props, gst_props_entry_new ("endianness", GST_PROPS_INT (G_BYTE_ORDER)));
break;
}
}
return props;
} else if (snd_pcm_format_float (format)) {
/* no float with non-platform endianness */
if (!snd_pcm_format_cpu_endian (format))
return NULL;
return gst_props_new ("format", GST_PROPS_STRING ("float"),
"layout", GST_PROPS_STRING (snd_pcm_format_width (format) == 64 ? "gdouble" : "gfloat"),
"intercept", GST_PROPS_FLOAT (0),
"slope", GST_PROPS_FLOAT (1),
NULL);
}
return NULL;
}
static inline void add_channels (GstProps *props, gint rate, gint channels) {
if (rate < 0) {
gst_props_add_entry (props, gst_props_entry_new ("rate", GST_PROPS_INT_RANGE (8000, 192000)));
} else {
gst_props_add_entry (props, gst_props_entry_new ("rate", GST_PROPS_INT (rate)));
}
if (channels < 0) {
gst_props_add_entry (props, gst_props_entry_new ("channels", GST_PROPS_INT_RANGE (1, GST_ALSA_MAX_CHANNELS)));
} else {
gst_props_add_entry (props, gst_props_entry_new ("channels", GST_PROPS_INT (channels)));
}
}
/**
* Get all available caps.
* @format: SND_PCM_FORMAT_UNKNOWN for all formats, desired format else
* @rate: allowed rates if < 0, else desired rate
* @channels: all allowed values for channels if < 0, else desired channels
*/
static GstCaps *
gst_alsa_caps (snd_pcm_format_t format, gint rate, gint channels)
{
GstCaps *ret_caps = NULL;
if (format != SND_PCM_FORMAT_UNKNOWN) {
/* there are some caps set already */
GstProps *props = gst_alsa_get_props (format);
/* we can never use a format we can't set caps for */
g_assert (props != NULL);
add_channels (props, rate, channels);
ret_caps = gst_caps_new ("alsacaps", "audio/raw", props);
} else {
int i;
GstProps *props;
for (i = 0; i <= SND_PCM_FORMAT_LAST; i++) {
props = gst_alsa_get_props (i);
/* can be NULL, because not all alsa formats can be specified as caps */
if (props != NULL) {
add_channels (props, rate, channels);
ret_caps = gst_caps_append (ret_caps, gst_caps_new (g_strdup (snd_pcm_format_name (i)),
"audio/raw", props));
}
}
}
return ret_caps;
}
/* Negotiates the caps */
GstPadLinkReturn
gst_alsa_link (GstPad *pad, GstCaps *caps)
{
GstAlsa *this;
snd_pcm_format_t format;
gint rate, channels;
g_return_val_if_fail (caps != NULL, GST_PAD_LINK_REFUSED);
g_return_val_if_fail (pad != NULL, GST_PAD_LINK_REFUSED);
this = GST_ALSA (gst_pad_get_parent (pad));
if (GST_CAPS_IS_FIXED (caps)) {
if (this->handle == NULL)
if (!gst_alsa_open_audio (this))
return GST_PAD_LINK_REFUSED;
format = gst_alsa_get_format (caps);
GST_DEBUG (GST_CAT_CAPS, "found format %s\n", snd_pcm_format_name (format));
/* FIXME: allow changing the format here, even by retrying caps on other pads */
if (format == SND_PCM_FORMAT_UNKNOWN || (this->format != SND_PCM_FORMAT_UNKNOWN && this->format != format))
return GST_PAD_LINK_REFUSED;
if (!gst_caps_get (caps, "rate", &rate,
"channels", &channels,
NULL))
return GST_PAD_LINK_REFUSED;
if (this->format != SND_PCM_FORMAT_UNKNOWN && this->rate != rate)
return GST_PAD_LINK_REFUSED;
if (this->format != SND_PCM_FORMAT_UNKNOWN && ((this->channels > 1 || channels > 1)))
return GST_PAD_LINK_REFUSED;
if (this->format == SND_PCM_FORMAT_UNKNOWN) {
this->channels = channels;
} else {
this->channels++;
}
this->format = format;
this->rate = rate;
/* sync the params */
if (GST_FLAG_IS_SET (this, GST_ALSA_RUNNING)) gst_alsa_stop_audio (this);
if (GST_FLAG_IS_SET (this, GST_ALSA_OPEN)) gst_alsa_close_audio (this);
if (!gst_alsa_open_audio (this)) return GST_PAD_LINK_REFUSED;
if (!gst_alsa_start_audio (this)) return GST_PAD_LINK_REFUSED;
return GST_PAD_LINK_OK;
}
return GST_PAD_LINK_DELAYED;
}
static GstBufferPool *
gst_alsa_src_get_buffer_pool (GstPad *pad)
{
int width, bytes_per_frame;
GstAlsa *this = GST_ALSA (gst_pad_get_parent (pad));
width = snd_pcm_format_physical_width (this->format);
bytes_per_frame = ( width / 8 ) * (GST_ELEMENT (this)->numpads == 1 ? this->channels : 1);
/* FIXME : is this right ? constant size buffers are probably a good thing,
but what if the size changes (e.g. during xrun autorecovery) ? */
return gst_buffer_pool_get_default (this->period_size * bytes_per_frame,
this->period_count);
}
static GstElementStateReturn
gst_alsa_change_state (GstElement *element)
{
GstAlsa *this;
g_return_val_if_fail (element != NULL, FALSE);
this = GST_ALSA (element);
switch (GST_STATE_TRANSITION (element)) {
case GST_STATE_NULL_TO_READY:
if (GST_FLAG_IS_SET (element, GST_ALSA_OPEN) == FALSE)
if (!gst_alsa_open_audio (this))
return GST_STATE_FAILURE;
break;
case GST_STATE_READY_TO_PAUSED:
break;
case GST_STATE_PAUSED_TO_PLAYING:
if (GST_FLAG_IS_SET (element, GST_ALSA_RUNNING) == FALSE)
if (!gst_alsa_start_audio (this))
return GST_STATE_FAILURE;
case GST_STATE_PLAYING_TO_PAUSED:
if (GST_FLAG_IS_SET (element, GST_ALSA_RUNNING))
gst_alsa_drain_audio (this);
break;
case GST_STATE_PAUSED_TO_READY:
break;
case GST_STATE_READY_TO_NULL:
if (GST_FLAG_IS_SET (element, GST_ALSA_OPEN))
gst_alsa_close_audio (this);
break;
default:
g_assert_not_reached();
}
if (GST_ELEMENT_CLASS (parent_class)->change_state)
return GST_ELEMENT_CLASS (parent_class)->change_state (element);
return GST_STATE_SUCCESS;
}
/*** AUDIO PROCESSING *********************************************************/
static int
gst_alsa_do_mmap (GstAlsa *this, guint numpads, snd_pcm_sframes_t *avail)
{
snd_pcm_uframes_t offset;
snd_pcm_channel_area_t *dst, *src, *areas;
int i, err, width = snd_pcm_format_physical_width (this->format);
/* areas points to the memory areas that belong to gstreamer. */
if (G_OBJECT_TYPE (this) == GST_TYPE_ALSA_SRC) {
areas = dst = calloc(this->channels, sizeof(snd_pcm_channel_area_t));
} else {
areas = src = calloc(this->channels, sizeof(snd_pcm_channel_area_t));
}
if (numpads == 1) {
/* interleaved */
for (i = 0; i < this->channels; i++) {
areas[i].addr = this->pads[0].data;
areas[i].first = i * width;
areas[i].step = this->channels * width;
}
} else {
/* noninterleaved */
for (i = 0; i < this->channels; i++) {
areas[i].addr = this->pads[i].data;
areas[i].first = 0;
areas[i].step = width;
}
}
/* might want to try to do some pointer sneakery in the first if block to get
rid of this second if block ... but right now i'm too sleepy */
if (G_OBJECT_TYPE (this) == GST_TYPE_ALSA_SRC) {
if ((err = snd_pcm_mmap_begin (this->handle, (const snd_pcm_channel_area_t **) &src, &offset, avail)) < 0) {
g_warning ("gstalsa: mmap failed: %s", snd_strerror (err));
return -1;
}
} else {
if ((err = snd_pcm_mmap_begin (this->handle, (const snd_pcm_channel_area_t **) &dst, &offset, avail)) < 0) {
g_warning ("gstalsa: mmap failed: %s", snd_strerror (err));
return -1;
}
}
if ((err = snd_pcm_areas_copy (dst, offset, src, 0, this->channels, *avail, this->format)) < 0) {
snd_pcm_mmap_commit (this->handle, offset, 0);
g_warning ("gstalsa: data copy failed: %s", snd_strerror (err));
return -1;
}
if ((err = snd_pcm_mmap_commit (this->handle, offset, *avail)) < 0) {
g_warning ("gstalsa: mmap commit failed: %s", snd_strerror (err));
return -1;
}
return err;
}
inline static snd_pcm_sframes_t
gst_alsa_update_avail (GstAlsa *this)
{
snd_pcm_sframes_t avail = snd_pcm_avail_update (this->handle);
if (avail < 0) {
if (avail == -EPIPE) {
gst_alsa_xrun_recovery (this);
return -EPIPE;
} else {
g_warning ("unknown ALSA avail_update return value (%d)", (int) avail);
return -1;
}
}
return avail;
}
inline static gint
gst_alsa_pcm_wait (GstAlsa *this)
{
if (snd_pcm_state (this->handle) == SND_PCM_STATE_RUNNING) {
if (snd_pcm_wait (this->handle, 1000) < 0) {
if (errno == EINTR) {
/* happens mostly when run under gdb, or when exiting due to a signal */
GST_DEBUG (GST_CAT_PLUGIN_INFO, "got interrupted while waiting");
if (gst_element_interrupt (GST_ELEMENT (this)))
return -1;
}
g_warning ("error waiting for alsa pcm: (%d: %s)", errno, strerror (errno));
return -1;
}
}
return 0;
}
static void
gst_alsa_sink_loop (GstElement *element)
{
snd_pcm_sframes_t avail, copied;
gint i;
gint bytes, num_bytes; /* per channel */
GstAlsa *this = GST_ALSA (element);
g_return_if_fail (this != NULL);
/* caps nego: fetch 1 byte from every pad */
if (this->format == SND_PCM_FORMAT_UNKNOWN) {
GST_DEBUG (GST_CAT_NEGOTIATION, "starting caps negotiation");
for (i = 0; i < element->numpads; i++) {
g_assert (this->pads[i].pad != NULL);
do {
num_bytes = gst_bytestream_peek_bytes (this->pads[i].bs, &this->pads[i].data, 1);
} while (num_bytes == 0 && gst_alsa_sink_check_event (this, i));
if (num_bytes == 0)
return;
}
if (this->format == SND_PCM_FORMAT_UNKNOWN) {
gst_element_error (GST_ELEMENT (this), "alsasink: No caps available");
}
}
sink_restart:
while (1) {
avail = gst_alsa_update_avail (this);
if (avail == -EPIPE) goto sink_restart;
if (avail == -1) break;
if (avail > 0) {
int width = snd_pcm_format_physical_width (this->format);
/* check how many bytes we still have in all our bytestreams */
bytes = avail * ( width / 8 ) * (element->numpads == 1 ? this->channels : 1);
for (i = 0; i < element->numpads; i++) {
g_assert (this->pads[i].pad != NULL);
do {
num_bytes = gst_bytestream_peek_bytes (this->pads[i].bs, &this->pads[i].data, bytes);
} while (num_bytes == 0 && gst_alsa_sink_check_event (this, i));
if (num_bytes == 0)
break;
bytes = MIN (bytes, num_bytes);
}
/* FIXME: lotsa stuff can have happened while fetching data. Do we need to check something? */
/* put this data into alsa */
avail = bytes / (width / 8 ) / (element->numpads == 1 ? this->channels : 1);
if ((copied = gst_alsa_do_mmap (this, element->numpads, &avail)) < 0)
break;
/* flush the data */
bytes = copied * ( width / 8 ) * (element->numpads == 1 ? this->channels : 1);
for (i = 0; i < element->numpads; i++)
gst_bytestream_flush (this->pads[i].bs, bytes);
/* BUG: we start the stream explicitly, autostart doesn't work correctly (alsa 0.9.0rc7) */
if (snd_pcm_state(this->handle) == SND_PCM_STATE_PREPARED && snd_pcm_avail_update (this->handle) == 0) {
GST_DEBUG (GST_CAT_PLUGIN_INFO, "Explicitly starting playback");
snd_pcm_start(this->handle);
}
}
/* wait */
if (gst_alsa_pcm_wait (this) < 0)
break;
}
}
static void
gst_alsa_src_loop (GstElement *element)
{
snd_pcm_sframes_t avail, copied;
GstBufferPool *pool = NULL;
GstBuffer *buf;
GstCaps *caps;
gint i;
GstAlsaPad *pad;
GstAlsa *this = GST_ALSA (element);
g_return_if_fail (this != NULL);
static gboolean caps_set = FALSE;
/* set the caps on all pads */
if (!caps_set) {
GST_DEBUG (GST_CAT_NEGOTIATION, "starting caps negotiation");
caps = gst_alsa_caps (this->format, this->rate, this->channels);
for (i = 0; i < element->numpads; i++) {
if (gst_pad_try_set_caps (this->pads[i].pad, caps) <= 0) {
GST_DEBUG (GST_CAT_NEGOTIATION, "setting caps (%p) in alsasrc (%p) on pad %d failed", caps, this, i);
return;
}
}
caps_set = TRUE;
}
src_restart:
while (1) {
avail = gst_alsa_update_avail (this);
if (avail == -EPIPE) goto src_restart;
if (avail == -1) break;
if (avail > 0) {
int width = snd_pcm_format_physical_width (this->format);
int bytes_per_frame = ( width / 8 ) * (element->numpads == 1 ? this->channels : 1);
if ((copied = gst_alsa_do_mmap (this, element->numpads, &avail)) < 0)
break;
/* we get the buffer pool once per go round */
if (! pool) pool = gst_alsa_src_get_buffer_pool (this->pads[0].pad);
/* push the data to gstreamer if it's big enough to fill up a buffer. */
for (i = 0; i < element->numpads; i++) {
pad = &this->pads[i];
pad->offset += MIN (copied, this->period_size - pad->offset);
if (pad->offset >= this->period_size) {
g_assert (pad->offset <= this->period_size);
buf = gst_buffer_new_from_pool (pool, 0, 0);
GST_BUFFER_DATA (buf) = pad->data;
GST_BUFFER_SIZE (buf) = this->period_size * bytes_per_frame;
GST_BUFFER_MAXSIZE (buf) = this->period_size * bytes_per_frame;
gst_pad_push (pad->pad, buf);
pad->data = NULL;
pad->offset = 0;
}
}
pool = NULL;
/* BUG: we start the stream explicitly, autostart doesn't work correctly (alsa 0.9.0rc7) */
if (snd_pcm_state(this->handle) == SND_PCM_STATE_PREPARED && snd_pcm_avail_update (this->handle) == 0) {
GST_DEBUG (GST_CAT_PLUGIN_INFO, "Explicitly starting capture");
snd_pcm_start(this->handle);
}
}
/* wait */
if (gst_alsa_pcm_wait (this) < 0)
break;
}
}
static void
gst_alsa_xrun_recovery (GstAlsa *this)
{
snd_pcm_status_t *status;
gint err;
snd_pcm_status_alloca (&status);
if ((err = snd_pcm_status (this->handle, status)) < 0)
g_warning ("status error: %s", snd_strerror (err));
if (snd_pcm_status_get_state (status) == SND_PCM_STATE_XRUN) {
struct timeval now, diff, tstamp;
gettimeofday (&now, 0);
snd_pcm_status_get_trigger_tstamp (status, &tstamp);
timersub (&now, &tstamp, &diff);
g_warning ("alsa: xrun of at least %.3f msecs", diff.tv_sec * 1000 + diff.tv_usec / 1000.0);
/* if we're allowed to recover, ... */
if (this->autorecover) {
/* ... then increase the period size or buffer size / period count to
prevent further xruns (at the cost of increased latency and memory
usage). */
if (this->period_count >= 4) {
this->period_size *= 2;
this->period_count /= 2;
} else {
this->period_count *= 2;
}
}
}
if (!(gst_alsa_stop_audio (this) && gst_alsa_start_audio (this))) {
gst_element_error (GST_ELEMENT (this), "alsasink: Error restarting audio after xrun");
}
}
/* TRUE, if everything should continue */
static gboolean
gst_alsa_sink_check_event (GstAlsa *this, gint pad_nr)
{
GstEvent *event = NULL;
guint32 avail;
gboolean cont = TRUE;
gst_bytestream_get_status (this->pads[pad_nr].bs, &avail, &event);
if (event) {
if (GST_EVENT_TYPE (event) == GST_EVENT_EOS) {
gst_element_set_eos (GST_ELEMENT (this));
cont = FALSE;
} else {
g_warning ("GstAlsaSink: got an unknown event (Type: %d)", GST_EVENT_TYPE (event));
}
gst_event_unref (event);
} else {
/* the element at the top of the chain did not emit an event. */
g_assert_not_reached ();
}
return cont;
}
/*** AUDIO SETUP / START / STOP ***********************************************/
static gboolean
gst_alsa_open_audio (GstAlsa *this)
{
g_assert (this != NULL);
g_assert (this->handle == NULL);
GST_INFO (GST_CAT_PLUGIN_INFO, "Opening alsa device \"%s\" for %s...\n", this->device,
this->stream == SND_PCM_STREAM_PLAYBACK ? "playback" : "capture");
ERROR_CHECK (snd_output_stdio_attach (&this->out, stdout, 0),
"error opening log output: %s");
/* blocking i/o */
ERROR_CHECK (snd_pcm_open (&this->handle, this->device, this->stream, 0),
"error opening pcm device %s: %s\n", this->device);
GST_FLAG_SET (this, GST_ALSA_OPEN);
return TRUE;
}
/* you must set all hw parameters at once - thx ALSA for not documenting this */
static gboolean
gst_alsa_set_hw_params (GstAlsa *this)
{
snd_pcm_hw_params_t *hw_params;
snd_pcm_access_mask_t *mask;
snd_pcm_uframes_t size_min, size_max;
unsigned int count_min, count_max;
/* whether to use default values when setting params */
gboolean def = (this->format == SND_PCM_FORMAT_UNKNOWN);
g_return_val_if_fail (this != NULL, FALSE);
g_return_val_if_fail (this->handle != NULL, FALSE);
GST_INFO (GST_CAT_PLUGIN_INFO, "Preparing channel: %s %dHz, %d channels\n",
snd_pcm_format_name (this->format), this->rate, this->channels);
snd_pcm_hw_params_alloca (&hw_params);
ERROR_CHECK (snd_pcm_hw_params_any (this->handle, hw_params),
"Broken configuration for this PCM: %s");
ERROR_CHECK (snd_pcm_hw_params_set_periods_integer (this->handle, hw_params),
"cannot restrict period size to integral value: %s");
mask = alloca (snd_pcm_access_mask_sizeof ());
snd_pcm_access_mask_none (mask);
if (GST_ELEMENT (this)->numpads == 1) {
snd_pcm_access_mask_set (mask, SND_PCM_ACCESS_MMAP_INTERLEAVED);
} else {
snd_pcm_access_mask_set (mask, SND_PCM_ACCESS_MMAP_NONINTERLEAVED);
}
ERROR_CHECK (snd_pcm_hw_params_set_access_mask (this->handle, hw_params, mask),
"The Gstreamer ALSA plugin does not support your hardware. Error: %s");
ERROR_CHECK (snd_pcm_hw_params_set_format (this->handle, hw_params, def ? SND_PCM_FORMAT_S16 : this->format),
"Sample format (%s) not available: %s", snd_pcm_format_name (def ? SND_PCM_FORMAT_S16 : this->format));
ERROR_CHECK (snd_pcm_hw_params_set_channels (this->handle, hw_params, this->channels),
"Channels count (%d) not available: %s", this->channels);
ERROR_CHECK (snd_pcm_hw_params_set_rate (this->handle, hw_params, def ? 44100 : this->rate, 0),
"error setting rate (%d): %s", def ? 44100 : this->rate);
if (snd_pcm_hw_params_get_period_size_min (hw_params, &size_min, 0) < 0) size_min = this->period_size;
if (snd_pcm_hw_params_get_period_size_max (hw_params, &size_max, 0) < 0) size_max = this->period_size;
g_assert (size_max >= size_min);
if (size_min > this->period_size) this->period_size = size_min;
if (size_max < this->period_size) this->period_size = size_max;
ERROR_CHECK (snd_pcm_hw_params_set_period_size (this->handle, hw_params, this->period_size, 0),
"error setting period size to %u frames: %s", (guint) this->period_size);
if (snd_pcm_hw_params_get_periods_min (hw_params, &count_min, 0) < 0) count_min = this->period_count;
if (snd_pcm_hw_params_get_periods_max (hw_params, &count_max, 0) < 0) count_max = this->period_count;
g_assert (count_max >= count_min);
if (count_min > this->period_count) this->period_count = count_min;
if (count_max < this->period_count) this->period_count = count_max;
ERROR_CHECK (snd_pcm_hw_params_set_buffer_size (this->handle, hw_params, this->period_size * this->period_count),
"error setting buffer size to %u: %s", (guint) (this->period_size * this->period_count));
ERROR_CHECK (snd_pcm_hw_params (this->handle, hw_params),
"Could not set hardware parameters: %s");
return TRUE;
}
static gboolean
gst_alsa_set_sw_params (GstAlsa *this)
{
snd_pcm_sw_params_t *sw_params;
snd_pcm_sw_params_alloca (&sw_params);
ERROR_CHECK (snd_pcm_sw_params_current (this->handle, sw_params),
"Could not get current software parameters: %s");
ERROR_CHECK (snd_pcm_sw_params_set_silence_size (this->handle, sw_params, 0),
"could not set silence size: %s");
ERROR_CHECK (snd_pcm_sw_params_set_silence_threshold (this->handle, sw_params, 0),
"could not set silence threshold: %s");
ERROR_CHECK (snd_pcm_sw_params_set_avail_min (this->handle, sw_params, this->period_size),
"could not set avail min: %s");
ERROR_CHECK (snd_pcm_sw_params_set_start_threshold (this->handle, sw_params, 1),
"could not set start mode: %s");
ERROR_CHECK (snd_pcm_sw_params_set_stop_threshold (this->handle, sw_params, this->period_size * this->period_count),
"could not set stop mode: %s");
ERROR_CHECK (snd_pcm_sw_params_set_xfer_align(this->handle, sw_params, 1),
"Unable to set transfer align for playback: %s");
ERROR_CHECK (snd_pcm_sw_params (this->handle, sw_params),
"could not set sw_params: %s");
return TRUE;
}
static gboolean
gst_alsa_start_audio (GstAlsa *this)
{
if (!gst_alsa_set_hw_params (this))
return FALSE;
if (!gst_alsa_set_sw_params (this))
return FALSE;
GST_FLAG_SET (this, GST_ALSA_RUNNING);
return TRUE;
}
static gboolean
gst_alsa_drain_audio (GstAlsa *this) {
g_assert (this != NULL);
g_return_val_if_fail (this != NULL, FALSE);
g_return_val_if_fail (this->handle != NULL, FALSE);
GST_DEBUG (GST_CAT_PLUGIN_INFO, "stopping alsa");
if (this->stream == SND_PCM_STREAM_PLAYBACK) {
ERROR_CHECK (snd_pcm_drain (this->handle),
"couldn't stop and drain buffer: %s");
}
GST_FLAG_UNSET (this, GST_ALSA_RUNNING);
return TRUE;
}
static gboolean
gst_alsa_stop_audio (GstAlsa *this)
{
g_assert (this != NULL);
g_return_val_if_fail (this != NULL, FALSE);
g_return_val_if_fail (this->handle != NULL, FALSE);
GST_DEBUG (GST_CAT_PLUGIN_INFO, "stopping alsa, skipping pending frames");
if (this->stream == SND_PCM_STREAM_PLAYBACK) {
ERROR_CHECK (snd_pcm_drop (this->handle),
"couldn't stop (dropping frames): %s");
}
GST_FLAG_UNSET (this, GST_ALSA_RUNNING);
return TRUE;
}
static gboolean
gst_alsa_close_audio (GstAlsa *this)
{
g_return_val_if_fail (this != NULL, FALSE);
g_return_val_if_fail (this->handle != NULL, FALSE);
ERROR_CHECK (snd_pcm_close (this->handle), "Error closing device: %s");
this->handle = NULL;
GST_FLAG_UNSET (this, GST_ALSA_OPEN);
return TRUE;
}
/*** GSTREAMER PLUGIN *********************************************************/
static gboolean
plugin_init (GModule * module, GstPlugin * plugin)
{
GstElementFactory *factory;
if (!gst_library_load ("gstbytestream"))
return FALSE;
factory = gst_element_factory_new ("alsasrc", GST_TYPE_ALSA_SRC, &gst_alsa_src_details);
g_return_val_if_fail (factory != NULL, FALSE);
gst_element_factory_add_pad_template (factory, gst_alsa_src_pad_factory ());
gst_element_factory_add_pad_template (factory, gst_alsa_src_request_pad_factory ());
gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));
factory = gst_element_factory_new ("alsasink", GST_TYPE_ALSA_SINK, &gst_alsa_sink_details);
g_return_val_if_fail (factory != NULL, FALSE);
gst_element_factory_add_pad_template (factory, gst_alsa_sink_pad_factory ());
gst_element_factory_add_pad_template (factory, gst_alsa_sink_request_pad_factory ());
gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));
gst_plugin_set_longname (plugin, "ALSA plugin library");
return TRUE;
}
GstPluginDesc plugin_desc = {
GST_VERSION_MAJOR,
GST_VERSION_MINOR,
"alsa",
plugin_init
};
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