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gstreamer/ext/alsa/gstalsa.c
Benjamin Otte 59f2a30f72 cleaning up alsa, step 1: cleaning up caps parsing/setting and templates 
Original commit message from CVS:
cleaning up alsa, step 1: cleaning up caps parsing/setting and templates
- gst-launch ... ! spider ! alsasink works now
- alsasrc definitely does not work
2003-01-30 18:30:30 +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>
*
* 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"
/* 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>",
"(C) 2001 "
};
/* 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>",
"(C) 2001"
};
/* 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 GstElementStateReturn gst_alsa_change_state (GstElement *element);
/* audio processing functions */
static void gst_alsa_loop (GstElement *element);
static void gst_alsa_xrun_recovery (GstAlsa *this);
static gboolean gst_alsa_src_process (GstAlsa *this, snd_pcm_uframes_t frames);
static gboolean gst_alsa_sink_process (GstAlsa *this, snd_pcm_uframes_t frames);
static void gst_alsa_sink_check_event (GstAlsa *this, GstAlsaPad *pad);
/* alsa setup / start / stop functions */
static gboolean gst_alsa_set_params (GstAlsa *this);
static gboolean gst_alsa_open_audio (GstAlsa *this);
static gboolean gst_alsa_start_audio (GstAlsa *this);
static void gst_alsa_stop_audio (GstAlsa *this);
static void gst_alsa_close_audio (GstAlsa *this);
static gboolean gst_alsa_get_channel_addresses (GstAlsa *this);
static void gst_alsa_release_channel_addresses (GstAlsa *this);
/* #define _DEBUG */
#ifdef _DEBUG
#define DEBUG(text, args...) g_message(text, ##args)
#else
#define DEBUG(text, args...)
#endif
/*** 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_PERIODFRAMES,
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));
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, 64, 2, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
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_PARAM_CONSTRUCT));
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_PERIODFRAMES,
g_param_spec_int ("period-frames", "Period frames", "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_DEBUG,
g_param_spec_boolean ("debug", "Debug", "Set to TRUE to output PCM state info",
FALSE, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_AUTORECOVER,
g_param_spec_boolean ("autorecover", "Automatic xrun recovery", "Set to TRUE to increase the period count 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)
{
/* init values */
this->handle = NULL;
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 */
this->process = gst_alsa_src_process;
this->pads = g_list_append (NULL, g_new0 (GstAlsaPad, 1));
GST_ALSA_PAD (this->pads)->pad =
gst_pad_new_from_template (gst_alsa_src_pad_factory (), "src");
} 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 */
this->process = gst_alsa_sink_process;
this->pads = g_list_append (NULL, g_new0 (GstAlsaPad, 1));
GST_ALSA_PAD (this->pads)->pad =
gst_pad_new_from_template (gst_alsa_sink_pad_factory (), "sink");
}
GST_ALSA_PAD (this->pads)->channel = -1;
/* data is interleaved by default, because there's only one default pad */
this->data_interleaved = TRUE;
this->rate = 0;
this->channels = 0;
gst_element_add_pad (GST_ELEMENT (this), GST_ALSA_PAD (this->pads)->pad);
gst_pad_set_link_function (GST_ALSA_PAD (this->pads)->pad, gst_alsa_link);
gst_element_set_loop_function (GST_ELEMENT (this), gst_alsa_loop);
}
static void
gst_alsa_set_property (GObject *object, guint prop_id, const GValue *value,
GParamSpec *pspec)
{
GstAlsa *this;
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:
this->format = g_value_get_enum (value);
break;
case ARG_CHANNELS:
this->channels = g_value_get_int (value);
break;
case ARG_RATE:
this->rate = g_value_get_int (value);
break;
case ARG_PERIODCOUNT:
this->period_count = g_value_get_int (value);
this->buffer_frames = this->period_count * this->period_frames;
break;
case ARG_PERIODFRAMES:
this->period_frames = g_value_get_int (value);
this->buffer_frames = this->period_count * this->period_frames;
break;
case ARG_DEBUG:
this->debug = g_value_get_boolean (value);
return;
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_set_params (this);
gst_alsa_start_audio (this);
} else {
gst_alsa_set_params (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_PERIODFRAMES:
g_value_set_int (value, this->period_frames);
break;
case ARG_DEBUG:
g_value_set_boolean (value, this->debug);
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;
GstAlsaPad *pad;
gint channel;
gchar *newname;
GList *l;
g_return_val_if_fail ((this = GST_ALSA (element)), NULL);
/* you can't request a pad if the non-request pad is connected */
g_return_val_if_fail (this->data_interleaved == FALSE ||
this->pads == NULL ||
GST_ALSA_PAD (this->pads) == NULL ||
GST_ALSA_PAD (this->pads)->pad == NULL ||
GST_PAD_PEER (GST_ALSA_PAD (this->pads)->pad) == NULL,
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 = atoi (name + (strchr (templ->name_template, '%') -
templ->name_template));
/* make sure the requested channel is free. */
l = this->pads;
while (l) {
if (GST_ALSA_PAD (l)->channel == channel) {
g_warning ("requested channel %d already in use.", channel);
return NULL;
}
l = l->next;
}
newname = g_strdup (name);
} else {
channel = 0;
/* if the user doesn't care which channel, find the lowest channel number
that's free. */
l = this->pads;
while (l) {
if (GST_ALSA_PAD (l)->channel >= channel)
channel = GST_ALSA_PAD (l)->channel + 1;
l = l->next;
}
newname = g_strdup_printf (templ->name_template, channel);
}
/* set up a new GstAlsaPad struct to hold this channel's info. */
pad = g_new0 (GstAlsaPad, 1);
pad->channel = channel;
pad->pad = gst_pad_new_from_template (templ, newname);
gst_element_add_pad (GST_ELEMENT (this), pad->pad);
gst_pad_set_link_function (pad->pad, gst_alsa_link);
/* if the only pad is the default (nonrequest) pad, then remove the current
pad (we know it's free from the above g_return_val_if_fail) */
if (this->data_interleaved && this->pads) {
gst_element_remove_pad (GST_ELEMENT (this), GST_ALSA_PAD (this->pads)->pad);
g_free (GST_ALSA_PAD (this->pads));
g_list_free (this->pads);
this->pads = NULL;
}
this->pads = g_list_append (this->pads, pad);
/* all request pads are mono (non-interleaved). FIXME: allow interleaved
access (for hw:N,M access on consumer hardware) */
if (this->data_interleaved) {
this->channels = pad->channel + 1;
this->data_interleaved = FALSE;
} else {
this->channels = MAX (this->channels, pad->channel + 1);
}
return pad->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, so lets find out which one we have.
* Somebody fix the float caps spec please.
*/
if (!gst_caps_get_string (caps, "format", &format_name))
return SND_PCM_FORMAT_UNKNOWN;
if (strncmp (format_name, "int", 3) == 0) {
gboolean sign;
int width, depth, endianness, law;
/* extract the needed information from the caps */
if (!gst_caps_get (caps,
"width", &width,
"depth", &depth,
"law", &law,
"endianness", &endianness,
"signed", &sign,
NULL))
return SND_PCM_FORMAT_UNKNOWN;
/* 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: return SND_PCM_FORMAT_A_LAW;
case 2: return SND_PCM_FORMAT_MU_LAW;
default: return SND_PCM_FORMAT_UNKNOWN;
}
} else if (strncmp (format_name, "float", 5) == 0) {
gchar *layout;
/* get layout */
if (!gst_caps_get_string (caps, "layout", (const gchar **) &layout))
return SND_PCM_FORMAT_UNKNOWN;
/* match layout to format wrt to endianness */
if (strncmp (layout, "gfloat", 6) == 0) {
return SND_PCM_FORMAT_FLOAT;
} else if (strncmp (layout, "gdouble", 7) == 0) {
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)
{
/* int or float */
if (snd_pcm_format_linear (format)) {
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)),
"signed", GST_PROPS_BOOLEAN (snd_pcm_format_signed (format) == 1 ? TRUE : FALSE),
NULL);
/* endianness */
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:
break;
}
/* law */
switch (format) {
case SND_PCM_FORMAT_A_LAW:
gst_props_add_entry (props, gst_props_entry_new ("law", GST_PROPS_INT (1)));
break;
case SND_PCM_FORMAT_MU_LAW:
gst_props_add_entry (props, gst_props_entry_new ("law", GST_PROPS_INT (2)));
break;
default:
gst_props_add_entry (props, gst_props_entry_new ("law", GST_PROPS_INT (0)));
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"),
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, 64)));
} 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 channel number
*/
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, "borrowed" from gstosssink.c */
GstPadLinkReturn
gst_alsa_link (GstPad *pad, GstCaps *caps)
{
GstAlsa *this;
snd_pcm_format_t format;
gint rate, channels;
gboolean need_mmap;
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;
/* FIXME: allow changing the format here */
format = gst_alsa_get_format (caps);
DEBUG ("found format %s\n", snd_pcm_format_name (format));
if (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;
need_mmap = this->mmap_open;
/* 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);
/* FIXME send out another caps if nego fails */
if (!gst_alsa_open_audio (this)) return GST_PAD_LINK_REFUSED;
if (!gst_alsa_start_audio (this)) return GST_PAD_LINK_REFUSED;
if (need_mmap && !gst_alsa_get_channel_addresses (this))
return GST_PAD_LINK_REFUSED;
return GST_PAD_LINK_OK;
}
return GST_PAD_LINK_DELAYED;
}
static GstElementStateReturn
gst_alsa_change_state (GstElement *element)
{
GstAlsa *this;
GList *l;
g_return_val_if_fail (element != NULL, FALSE);
this = GST_ALSA (element);
switch (GST_STATE_PENDING (element)) {
case GST_STATE_NULL:
if (GST_FLAG_IS_SET (element, GST_ALSA_RUNNING)) gst_alsa_stop_audio (this);
if (GST_FLAG_IS_SET (element, GST_ALSA_OPEN)) gst_alsa_close_audio (this);
/* clear out bytestreams as well. */
l = this->pads;
while (l) {
if (GST_ALSA_PAD (l)->bs)
gst_bytestream_destroy (GST_ALSA_PAD (l)->bs);
l = l->next;
}
break;
case GST_STATE_READY:
break;
case GST_STATE_PAUSED:
if (GST_FLAG_IS_SET (element, GST_ALSA_OPEN) == FALSE)
if (!gst_alsa_open_audio (this))
return GST_STATE_FAILURE;
if (GST_FLAG_IS_SET (element, GST_ALSA_RUNNING))
gst_alsa_stop_audio (this);
break;
case GST_STATE_PLAYING:
if (GST_FLAG_IS_SET (element, GST_ALSA_RUNNING) == FALSE)
if (!gst_alsa_start_audio (this))
return GST_STATE_FAILURE;
break;
}
if (GST_ELEMENT_CLASS (parent_class)->change_state)
return GST_ELEMENT_CLASS (parent_class)->change_state (element);
return GST_STATE_SUCCESS;
}
/*** AUDIO PROCESSING *********************************************************/
/* shamelessly stolen from pbd's audioengine and jack alsa_driver. thanks,
paul! */
static void
gst_alsa_loop (GstElement *element)
{
GstAlsa *this = GST_ALSA (element);
g_return_if_fail (this != NULL);
while (1) {
if (snd_pcm_wait (this->handle, 1000) < 0) {
if (errno == EINTR) {
/* this happens mostly when run
* under gdb, or when exiting due to a signal */
g_print ("EINTR\n");
if (gst_element_interrupt (element))
break;
else
continue;
}
g_warning ("error waiting for alsa pcm: (%d: %s)", errno, strerror (errno));
return;
}
this->avail = snd_pcm_avail_update (this->handle);
DEBUG ("snd_pcm_avail_update() = %d", (int) this->avail);
if (this->avail < 0) {
if (this->avail == -EPIPE) {
gst_alsa_xrun_recovery (this);
this->avail = 0;
} else {
g_warning ("unknown ALSA avail_update return value (%d)", (int) this->avail);
return;
}
}
/* round down to nearest period_frames avail */
this->avail -= this->avail % this->period_frames;
DEBUG ("snd_pcm_avail_update(), rounded down = %d", (int) this->avail);
/* the available bytes might not be contiguous */
while (this->avail > 0) {
if (!gst_alsa_get_channel_addresses (this)) {
g_error ("could not get channels");
return;
}
if (! (this->mute && this->stream == SND_PCM_STREAM_PLAYBACK))
if (!this->process (this, this->avail)) {
g_warning ("alsa: something happened while processing audio");
return;
}
/* releasing channel addresses sets this->avail to 0. */
if (this->mmap_open)
gst_alsa_release_channel_addresses (this);
}
if (gst_element_interrupt (element))
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);
}
gst_alsa_stop_audio (this);
/* increase the period count to prevent further xruns (at the cost of
increased latency and memory usage). only do this if it's allowed. */
if ((this->period_count <= 32) && this->autorecover) {
this->period_count *= 2;
this->buffer_frames = this->period_count * this->period_frames;
gst_alsa_set_params(this);
}
gst_alsa_start_audio (this);
}
/* FIXME: DO NOT RECORD WITH ALSA, IT DOESN'T WORK, IT ONLY COMPILES */
static gboolean
gst_alsa_src_process (GstAlsa *this, snd_pcm_uframes_t frames)
{
GstAlsaPad *pad = NULL;
GstBuffer *buf;
GstCaps *caps;
GList *l;
guint32 channel;
gint unit;
static gboolean caps_set = FALSE;
/* let's get on the caps-setting merry-go-round! */
if (!caps_set) {
caps = gst_alsa_caps (this->format, this->rate, this->channels);
l = this->pads;
while (l) {
if (gst_pad_try_set_caps (GST_ALSA_PAD (l)->pad, caps) <= 0) {
DEBUG ("setting caps (%p) in source (%p) failed\n", caps, this);
sleep (1);
return FALSE;
}
l = l->next;
}
caps_set = TRUE;
}
unit = this->sample_bytes * (this->data_interleaved ? this->channels : 1);
/* pull the same amount of data into each pad. create an outgoing buffer with
the data, and push the buffer. lather, rinse, repeat. */
while (frames) {
l = this->pads;
while (l) {
pad = GST_ALSA_PAD (l);
if (!pad->buf)
pad->buf = g_malloc (this->period_frames * unit);
channel = (pad->channel > 0) ? pad->channel - 1 : 0;
memcpy (pad->buf + pad->offset * unit, this->access_addr[channel],
MIN (frames, this->period_frames - pad->offset) * unit);
pad->offset += MIN (frames, this->period_frames - pad->offset);
if (pad->offset >= this->period_frames) {
g_assert (pad->offset <= this->period_frames);
buf = gst_buffer_new ();
GST_BUFFER_DATA (buf) = pad->buf;
GST_BUFFER_SIZE (buf) = this->period_frames * unit;
GST_BUFFER_MAXSIZE (buf) = this->period_frames * unit;
gst_pad_push (pad->pad, buf);
pad->buf = NULL;
pad->offset = 0;
}
l = l->next;
}
/* all pads should have the same amount of data, shouldn't matter which one
we use for updating output frames ... */
frames -= MIN (frames, this->period_frames - pad->offset);
}
return TRUE;
}
static gboolean
gst_alsa_sink_process (GstAlsa *this, snd_pcm_uframes_t frames)
{
guint8 *peeked;
guint32 len, channel, num_peeked = 0;
gboolean muted;
GstAlsaPad *pad;
GList *l;
/* we need to check sample bytes here because the sample_bytes will change,
probably, when caps are set, which will occur after the first
bytestream_peek. we underestimate the amount of data we will need by
peeking "frames" bytes only. */
if (!this->sample_bytes) {
pad = GST_ALSA_PAD (this->pads);
if (!pad->bs)
pad->bs = gst_bytestream_new (pad->pad);
while (num_peeked == 0) {
num_peeked = gst_bytestream_peek_bytes (pad->bs, &peeked, frames);
if (num_peeked == 0) {
gst_alsa_sink_check_event (this, pad);
} else if (num_peeked < frames) {
g_warning ("could not make initial pull of %d bytes on pad %s:%s",
(int) frames, GST_DEBUG_PAD_NAME (pad->pad));
gst_element_set_eos (GST_ELEMENT (this));
return FALSE;
}
}
if (!this->sample_bytes) {
g_critical ("alsa plugin requires a pipeline that can adequately set caps.");
return FALSE;
}
}
len = frames * this->channels * this->sample_bytes;
/* write len bytes out to each of our pads' mmap_area pointers. */
l = this->pads;
while (l) {
pad = GST_ALSA_PAD (l);
channel = (pad->channel > 0) ? pad->channel - 1 : 0;
muted = (1 << channel) && this->mute;
if (!pad->bs)
pad->bs = gst_bytestream_new (pad->pad);
num_peeked = gst_bytestream_peek_bytes (pad->bs, &peeked, len);
if (num_peeked == 0) {
gst_alsa_sink_check_event (this, pad);
} else if (peeked && this->access_addr[channel] && (! muted)) {
memcpy (this->access_addr[channel], peeked, num_peeked);
gst_bytestream_flush (pad->bs, num_peeked);
} else {
g_warning ("error while writing %u bytes (peeked into %p) to %p",
num_peeked, peeked, this->access_addr[channel]);
}
l = l->next;
}
return TRUE;
}
static void
gst_alsa_sink_check_event (GstAlsa *this, GstAlsaPad *pad)
{
GstEvent *event = NULL;
guint8 *peeked;
guint32 avail, channel, num_peeked = 0;
gst_bytestream_get_status (pad->bs, &avail, &event);
if (event) {
if (GST_EVENT_TYPE (event) == GST_EVENT_EOS) {
channel = (pad->channel > 0) ? pad->channel - 1 : 0;
num_peeked = gst_bytestream_peek_bytes (pad->bs, &peeked, avail);
if (num_peeked && peeked)
memcpy (this->access_addr[channel], peeked, num_peeked);
gst_element_set_eos (GST_ELEMENT (this));
gst_event_unref (event);
/* FIXME: remove this alsa pad from the element */
} else {
g_warning ("GstAlsaSink: got an unknown event (Type: %d)", GST_EVENT_TYPE (event));
}
} else {
/* the element at the top of the chain did not emit an event. */
g_assert_not_reached ();
}
}
/*** AUDIO SETUP / START / STOP ***********************************************/
/* taken more or less from pbd's audioengine code */
static gboolean
gst_alsa_set_params (GstAlsa *this)
{
snd_pcm_sw_params_t *sw_param;
snd_pcm_hw_params_t *hw_param;
snd_pcm_access_mask_t *mask;
gint ret;
g_return_val_if_fail (this != NULL, FALSE);
g_return_val_if_fail (this->handle != NULL, FALSE);
DEBUG ("Preparing channel: %s %dHz, %d channels\n",
snd_pcm_format_name (this->format), this->rate, this->channels);
snd_pcm_hw_params_alloca (&hw_param);
snd_pcm_sw_params_alloca (&sw_param);
ret = snd_pcm_hw_params_any (this->handle, hw_param);
if (ret < 0) {
g_warning ("Broken configuration for this PCM: no configurations available");
return FALSE;
}
if ((ret = snd_pcm_hw_params_set_periods_integer (this->handle, hw_param)) < 0) {
g_warning ("cannot restrict period size to integral value.");
return FALSE;
}
mask = alloca (snd_pcm_access_mask_sizeof ());
snd_pcm_access_mask_none (mask);
if (this->data_interleaved)
snd_pcm_access_mask_set (mask, SND_PCM_ACCESS_MMAP_INTERLEAVED);
snd_pcm_access_mask_set (mask, SND_PCM_ACCESS_MMAP_NONINTERLEAVED);
ret = snd_pcm_hw_params_set_access_mask (this->handle, hw_param, mask);
if (ret < 0) {
g_warning ("the gstreamer alsa plugin does not support your hardware.");
return FALSE;
}
if (this->format != SND_PCM_FORMAT_UNKNOWN) {
ret = snd_pcm_hw_params_set_format (this->handle, hw_param, this->format);
if (ret < 0) {
g_warning ("Sample format (%s) not available: %s",
snd_pcm_format_name (this->format), snd_strerror (ret));
return FALSE;
}
this->sample_bytes = snd_pcm_format_physical_width (this->format) / 8;
}
if (this->channels > 0) {
ret = snd_pcm_hw_params_set_channels (this->handle, hw_param, this->channels);
if (ret < 0) {
g_warning ("Channels count (%d) not available: %s", this->channels, snd_strerror (ret));
return FALSE;
}
this->channels = snd_pcm_hw_params_get_channels (hw_param);
}
if (this->rate > 0) {
ret = snd_pcm_hw_params_set_rate (this->handle, hw_param, this->rate, 0);
if (ret < 0) {
g_warning ("error setting rate (%d): %s", this->rate, snd_strerror (ret));
return FALSE;
}
}
if (this->period_count) {
ret = snd_pcm_hw_params_set_periods (this->handle, hw_param, this->period_count, 0);
if (ret < 0) {
g_warning ("error setting period count minimum (%d): %s",
this->period_count, snd_strerror (ret));
return FALSE;
}
}
if (this->period_frames) {
ret = snd_pcm_hw_params_set_period_size (this->handle, hw_param, this->period_frames, 0);
if (ret < 0) {
g_warning ("error setting period in frames (%d): %s",
this->period_frames, snd_strerror (ret));
return FALSE;
}
}
if (this->buffer_frames) {
ret = snd_pcm_hw_params_set_buffer_size (this->handle, hw_param, this->buffer_frames);
if (ret < 0) {
g_warning ("error setting buffer size (%d): %s", this->buffer_frames, snd_strerror (ret));
return FALSE;
}
}
ret = snd_pcm_hw_params (this->handle, hw_param);
if (ret < 0) {
g_warning ("could not set hw params: %s", snd_strerror (ret));
snd_pcm_hw_params_dump (hw_param, this->out);
return FALSE;
}
/* FIXME: this needs to be done for a src, but not for a sink
if (!this->rate)
this->rate = snd_pcm_hw_params_get_rate (hw_param, 0);
if (this->format == SND_PCM_UNKNOWN)
this->format = snd_pcm_hw_params_get_format (hw_param);
*/
if (!this->period_count)
this->period_count = snd_pcm_hw_params_get_periods (hw_param, 0);
if (!this->period_frames)
this->period_frames = snd_pcm_hw_params_get_period_size (hw_param, 0);
if (!this->buffer_frames)
this->buffer_frames = snd_pcm_hw_params_get_buffer_size (hw_param);
if (this->buffer_frames != this->period_count * this->period_frames)
g_critical ("buffer size != period size * number of periods, unexpected things may happen!");
snd_pcm_sw_params_current (this->handle, sw_param);
ret = snd_pcm_sw_params_set_start_threshold (this->handle, sw_param, ~0U);
if (ret < 0) {
g_warning ("could not set start mode: %s", snd_strerror (ret));
return FALSE;
}
ret = snd_pcm_sw_params_set_stop_threshold (this->handle, sw_param, this->buffer_frames);
if (ret < 0) {
g_warning ("could not set stop mode: %s", snd_strerror (ret));
return FALSE;
}
ret = snd_pcm_sw_params_set_silence_threshold (this->handle, sw_param, 0);
if (ret < 0) {
g_warning ("could not set silence threshold: %s", snd_strerror (ret));
return FALSE;
}
ret = snd_pcm_sw_params_set_silence_size (this->handle, sw_param, this->buffer_frames);
if (ret < 0) {
g_warning ("could not set silence size: %s", snd_strerror (ret));
return FALSE;
}
ret = snd_pcm_sw_params_set_avail_min (this->handle, sw_param, this->period_frames);
if (ret < 0) {
g_warning ("could not set avail min: %s", snd_strerror (ret));
return FALSE;
}
ret = snd_pcm_sw_params (this->handle, sw_param);
if (ret < 0) {
g_warning ("could not set sw_params: %s", snd_strerror (ret));
return FALSE;
}
if (this->debug)
snd_pcm_dump (this->handle, this->out);
this->access_interleaved = !(snd_pcm_hw_params_get_access (hw_param) ==
SND_PCM_ACCESS_MMAP_NONINTERLEAVED);
if (this->access_interleaved) {
this->interleave_unit = this->sample_bytes;
this->interleave_skip = this->interleave_unit * this->channels;
} else {
this->interleave_unit = 0; /* not used */
this->interleave_skip = this->sample_bytes;
}
if (this->access_addr)
g_free (this->access_addr);
this->access_addr = g_new0 (char *, this->channels);
return TRUE;
}
static gboolean
gst_alsa_open_audio (GstAlsa *this)
{
gint ret;
g_assert (this != NULL);
g_assert (this->handle == NULL);
if (this->handle)
gst_alsa_close_audio (this);
DEBUG ("Opening alsa device \"%s\" for %s...\n", this->device,
this->stream == SND_PCM_STREAM_PLAYBACK ? "playback" : "capture");
ret = snd_output_stdio_attach (&this->out, stdout, 0);
if (ret < 0) {
g_print ("error opening log output: %s\n", snd_strerror (ret));
return FALSE;
}
/* blocking i/o */
if ((ret = snd_pcm_open (&this->handle, this->device, this->stream, 0))) {
g_print ("error opening pcm device %s: %s\n", this->device, snd_strerror (ret));
return FALSE;
}
if (gst_alsa_set_params (this) == FALSE) {
gst_alsa_close_audio (this);
return FALSE;
}
GST_FLAG_SET (this, GST_ALSA_OPEN);
return TRUE;
}
static gboolean
gst_alsa_start_audio (GstAlsa *this)
{
gint err;
g_return_val_if_fail (this != NULL, FALSE);
g_return_val_if_fail (this->handle != NULL, FALSE);
if ((err = snd_pcm_prepare (this->handle)) < 0) {
g_warning ("channel prepare failed: %s", snd_strerror (err));
return FALSE;
}
this->avail = snd_pcm_avail_update (this->handle);
if (this->stream == SND_PCM_STREAM_PLAYBACK && this->avail != this->buffer_frames) {
g_warning ("full buffer not available at start");
return FALSE;
}
if (!gst_alsa_get_channel_addresses (this))
return FALSE;
gst_alsa_release_channel_addresses (this);
if ((err = snd_pcm_start (this->handle)) < 0) {
g_warning ("could not start audio: %s", snd_strerror (err));
return FALSE;
}
GST_FLAG_SET (this, GST_ALSA_RUNNING);
return TRUE;
}
static void
gst_alsa_stop_audio (GstAlsa *this)
{
gint err;
g_assert (this != NULL);
g_return_if_fail (this != NULL);
g_return_if_fail (this->handle != NULL);
if (this->mmap_open)
gst_alsa_release_channel_addresses (this);
if (this->stream == SND_PCM_STREAM_PLAYBACK && (err = snd_pcm_drop (this->handle)) < 0) {
g_warning ("channel flush failed: %s", snd_strerror (err));
return;
}
GST_FLAG_UNSET (this, GST_ALSA_RUNNING);
}
static void
gst_alsa_close_audio (GstAlsa *this)
{
g_return_if_fail (this != NULL);
g_return_if_fail (this->handle != NULL);
snd_pcm_close (this->handle);
this->handle = NULL;
GST_FLAG_UNSET (this, GST_ALSA_OPEN);
}
static gboolean
gst_alsa_get_channel_addresses (GstAlsa *this)
{
guint32 err, i;
const snd_pcm_channel_area_t *a;
g_return_val_if_fail (this->mmap_open == FALSE, FALSE);
if ((err = snd_pcm_mmap_begin (this->handle, &this->mmap_areas, &this->offset, &this->avail)) < 0) {
g_warning ("gstalsa: mmap failed: %s", snd_strerror (err));
return FALSE;
}
GST_DEBUG (0, "got %d mmap'd frames", (int) this->avail);
for (i = 0; i < this->channels; i++) {
a = &this->mmap_areas[i];
this->access_addr[i] =
(char *) a->addr + ((a->first + a->step * this->offset) / 8);
}
this->mmap_open = TRUE;
return TRUE;
}
static void
gst_alsa_release_channel_addresses (GstAlsa * this)
{
guint32 err, i;
g_return_if_fail (this->mmap_open == TRUE);
GST_DEBUG (0, "releasing mmap'd data region: %d frames", (int) this->avail);
if ((err = snd_pcm_mmap_commit (this->handle, this->offset, this->avail)) < 0) {
g_warning ("gstalsa: mmap commit failed: %s", snd_strerror (err));
return;
}
for (i = 0; i < this->channels; i++)
this->access_addr[i] = NULL;
this->mmap_open = FALSE;
this->avail = 0;
}
/*** 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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