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gstreamer/ext/alsa/gstalsa.c
Wim Taymans fe672ffe26 Fixed some plugins 
Original commit message from CVS:
Fixed some plugins
2001-12-28 20:24:41 +00:00

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/*
Copyright (C) 2001 CodeFactory AB
Copyright (C) 2001 Thomas Nyberg <thomas@codefactory.se>
Copyright (C) 2001 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 "gstalsa.h"
static GstElementDetails gst_alsa_sink_details = {
"Alsa Sink",
"Sink/Audio",
"Output to a sound card via ALSA: see plugins/alsa/README for more info",
VERSION,
"Thomas Nyberg <thomas@codefactory.se>, "
"Andy Wingo <apwingo@eos.ncsu.edu>",
"(C) 2001 "
};
static GstElementDetails gst_alsa_src_details = {
"Alsa Src",
"Source/Audio",
"Read from a sound card via ALSA: see plugins/alsa/README for more info",
VERSION,
"Thomas Nyberg <thomas@codefactory.se>, "
"Andy Wingo <apwingo@eos.ncsu.edu>"
"(C) 2001",
};
static GstElement *parent_class = NULL;
static void gst_alsa_init(GstAlsa *this);
static void gst_alsa_class_init(GstAlsaClass *klass);
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 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);
static GstElementStateReturn gst_alsa_change_state(GstElement *element);
static GstPadNegotiateReturn gst_alsa_negotiate(GstPad *pad, GstCaps **caps, gpointer *user_data);
static GstCaps* gst_alsa_caps (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_set_params(GstAlsa *this);
static void gst_alsa_loop (GstElement *element);
static gboolean gst_alsa_sink_process (GstAlsa *this, snd_pcm_uframes_t frames);
static gboolean gst_alsa_src_process (GstAlsa *this, snd_pcm_uframes_t frames);
static gboolean gst_alsa_get_channel_addresses (GstAlsa *this);
static void gst_alsa_release_channel_addresses (GstAlsa *this);
static void gst_alsa_sink_silence_on_channel (GstAlsa *this, guint32 chn, guint32 nframes);
static void memset_interleave (char *dst, char val, unsigned int bytes,
unsigned int unit_bytes,
unsigned int skip_bytes);
enum {
ARG_0,
ARG_DEVICE,
ARG_FORMAT,
ARG_CHANNELS,
ARG_RATE,
ARG_PERIODCOUNT,
ARG_PERIODFRAMES
};
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;
}
static GstPadTemplate*
gst_alsa_src_pad_factory(void)
{
static GstPadTemplate *template = NULL;
if (!template)
template = gst_padtemplate_new("src", GST_PAD_SRC, GST_PAD_SOMETIMES,
gst_caps_new("src", "audio/raw", NULL),
NULL);
return template;
}
static GstPadTemplate*
gst_alsa_src_request_pad_factory(void)
{
static GstPadTemplate *template = NULL;
if (!template)
template = gst_padtemplate_new("src%d", GST_PAD_SRC, GST_PAD_REQUEST,
gst_caps_new("src", "audio/raw",
gst_props_new("channels", GST_PROPS_INT(1), NULL)),
NULL);
return template;
}
static GstPadTemplate*
gst_alsa_sink_pad_factory(void)
{
static GstPadTemplate *template = NULL;
if (!template)
template = gst_padtemplate_new("sink", GST_PAD_SINK, GST_PAD_SOMETIMES,
gst_caps_new("sink", "audio/raw", NULL),
NULL);
return template;
}
static GstPadTemplate*
gst_alsa_sink_request_pad_factory(void)
{
static GstPadTemplate *template = NULL;
if (!template)
template = gst_padtemplate_new("sink%d", GST_PAD_SINK, GST_PAD_REQUEST,
gst_caps_new("sink-request", "audio/raw",
gst_props_new("channels", GST_PROPS_INT(1), NULL)),
NULL);
return template;
}
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: please see README for details",
"default",
G_PARAM_READWRITE));
g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_FORMAT,
g_param_spec_int("format","format","format",
0, SND_PCM_FORMAT_LAST, SND_PCM_FORMAT_S16,
G_PARAM_READWRITE));
g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_CHANNELS,
g_param_spec_int("channels","channels","channels",
1, 64, 1,
G_PARAM_READWRITE));
g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_RATE,
g_param_spec_int("rate","rate","rate",
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","period count",
2, 64, 2,
G_PARAM_READWRITE));
g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_PERIODFRAMES,
g_param_spec_int("period_frames","period frames","period frames",
64, 4096, 256,
G_PARAM_READWRITE));
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;
/* i tried to trim this down to only the essentials needed for proper
* functioning; we'll be setting this values 'in earnest' when caps come */
this->rate = 44100;
this->channels = 2;
/* i wish i could leave these to defaults, but when caps come and typically
* the number of channels doubles, you can't have the default count and size
* that alsa gives you from the pre-caps setup apply to the post-caps setup
* due to internal hw buffer size restrictions. these values seem to be
* pretty common, though, although not pushing latency limits */
this->period_count = 2;
this->period_frames = 4096;
this->device = g_strdup("default");
/* is this right? */
GST_FLAG_SET(this, GST_ELEMENT_THREAD_SUGGESTED);
if (G_OBJECT_TYPE(this) == GST_TYPE_ALSA_SRC) {
this->stream = SND_PCM_STREAM_CAPTURE;
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");
this->process = gst_alsa_src_process;
this->format = SND_PCM_FORMAT_S16; /* native endian */
} else if (G_OBJECT_TYPE(this) == GST_TYPE_ALSA_SINK) {
this->stream = SND_PCM_STREAM_PLAYBACK;
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");
this->process = gst_alsa_sink_process;
this->format = SND_PCM_FORMAT_UNKNOWN; /* we don't know until caps are
* set */
} else {
g_print("you cannot instantiate an object of type gstalsa. use alsasink or alsasrc instead.\n");
G_BREAKPOINT();
return;
}
GST_ALSA_PAD(this->pads)->channel = -1;
this->data_interleaved = TRUE;
gst_element_add_pad(GST_ELEMENT(this), GST_ALSA_PAD(this->pads)->pad);
gst_pad_set_negotiate_function(GST_ALSA_PAD(this->pads)->pad, gst_alsa_negotiate);
gst_element_set_loop_function(GST_ELEMENT(this), gst_alsa_loop);
}
static GstPad*
gst_alsa_request_new_pad (GstElement *element, GstPadTemplate *templ, const gchar *name)
{
GstAlsa *this;
gint channel;
gchar *newname;
GList *l;
GstAlsaPad *pad;
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) {
if (sscanf(name, templ->name_template, &channel) != 1) {
g_warning("invalid pad name %s (trying to fit with %s)", name,
templ->name_template);
return NULL;
}
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;
}
} else {
l = this->pads;
channel = 0;
while (l) {
if (GST_ALSA_PAD(l)->channel > channel)
channel = GST_ALSA_PAD(l)->channel;
l = l->next;
}
}
newname = g_strdup_printf (templ->name_template, channel);
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_negotiate_function(pad->pad, gst_alsa_negotiate);
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);
// 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;
}
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_int (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;
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_int (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;
default:
GST_DEBUG(0, "Unknown arg");
break;
}
}
static GstElementStateReturn
gst_alsa_change_state(GstElement *element)
{
GstAlsa *this;
guint chn;
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((GstAlsa *)element);
if (GST_FLAG_IS_SET(element, GST_ALSA_OPEN))
gst_alsa_close_audio((GstAlsa *)element);
/* FIXME: clean up bytestreams, etc */
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((GstAlsa *)element) == FALSE)
return GST_STATE_FAILURE;
if (GST_FLAG_IS_SET(element, GST_ALSA_RUNNING)) {
if (this->stream == SND_PCM_STREAM_PLAYBACK) {
for (chn = 0; chn < this->channels; chn++) {
gst_alsa_sink_silence_on_channel (this, chn, this->avail);
}
}
gst_alsa_stop_audio((GstAlsa *)element);
}
break;
case GST_STATE_PLAYING:
if (GST_FLAG_IS_SET(element, GST_ALSA_RUNNING) == FALSE)
if (gst_alsa_start_audio((GstAlsa *)element) == FALSE)
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;
}
static gboolean
gst_alsa_parse_caps (GstAlsa *this, GstCaps *caps)
{
gint law, endianness, width, depth;
gboolean sign;
gint format = -1;
const gchar* format_name;
format_name = gst_caps_get_string(caps, "format");
if (format_name == NULL) {
return FALSE;
} else if (strcmp(format_name, "int")==0) {
width = gst_caps_get_int (caps, "width");
depth = gst_caps_get_int (caps, "depth");
law = gst_caps_get_int (caps, "law");
endianness = gst_caps_get_int (caps, "endianness");
sign = gst_caps_get_boolean (caps, "signed");
if (law == 0) {
if (width == 8) {
if (sign == TRUE) {
format = SND_PCM_FORMAT_S8;
} else {
format = SND_PCM_FORMAT_U8;
}
} else if (width == 16) {
if (sign == TRUE) {
if (endianness == G_LITTLE_ENDIAN)
format = SND_PCM_FORMAT_S16_LE;
else if (endianness == G_BIG_ENDIAN)
format = SND_PCM_FORMAT_S16_BE;
} else {
if (endianness == G_LITTLE_ENDIAN)
format = SND_PCM_FORMAT_U16_LE;
else if (endianness == G_BIG_ENDIAN)
format = SND_PCM_FORMAT_U16_BE;
}
} else if (width == 24) {
if (sign == TRUE) {
if (endianness == G_LITTLE_ENDIAN)
format = SND_PCM_FORMAT_S24_LE;
else if (endianness == G_BIG_ENDIAN)
format = SND_PCM_FORMAT_S24_BE;
} else {
if (endianness == G_LITTLE_ENDIAN)
format = SND_PCM_FORMAT_U24_LE;
else if (endianness == G_BIG_ENDIAN)
format = SND_PCM_FORMAT_U24_BE;
}
} else if (width == 32) {
if (sign == TRUE) {
if (endianness == G_LITTLE_ENDIAN)
format = SND_PCM_FORMAT_S32_LE;
else if (endianness == G_BIG_ENDIAN)
format = SND_PCM_FORMAT_S32_BE;
} else {
if (endianness == G_LITTLE_ENDIAN)
format = SND_PCM_FORMAT_U32_LE;
else if (endianness == G_BIG_ENDIAN)
format = SND_PCM_FORMAT_U32_BE;
}
}
} else if (law == 1) { /* mu law */
if (width == depth && width == 8 && sign == FALSE) {
format = SND_PCM_FORMAT_MU_LAW;
} else {
return FALSE;
}
} else if (law == 2) { /* a law, ug. */
if (width == depth && width == 8 && sign == FALSE) {
format = SND_PCM_FORMAT_A_LAW;
}
} else {
return FALSE;
}
} else if (strcmp(format_name, "float")==0) {
if (strcmp(gst_caps_get_string(caps, "layout"), "gfloat")==0) {
format = SND_PCM_FORMAT_FLOAT;
} else {
return FALSE;
/* if you need float64, chat w/ me on irc.gstreamer.net and i'll tell you what needs to
* be done. i'm 'wingo'. */
}
} else {
return FALSE;
}
this->format = format;
this->rate = gst_caps_get_int(caps, "rate");
if (this->data_interleaved)
this->channels = gst_caps_get_int(caps, "channels");
else if (gst_caps_get_int(caps, "channels") != 1)
return FALSE;
return TRUE;
}
/* caps are so painful sometimes. */
static GstCaps*
gst_alsa_caps (GstAlsa *this)
{
gint law, endianness, width, depth;
gboolean sign;
GstProps *props;
g_return_val_if_fail (this != NULL && this->handle != NULL, NULL);
if (this->format == SND_PCM_FORMAT_FLOAT) {
props = gst_props_new ("format", GST_PROPS_STRING ("float"),
"layout", GST_PROPS_STRING ("gfloat"),
"rate", GST_PROPS_INT (this->rate),
"channels", GST_PROPS_INT ((this->data_interleaved ? this->channels : 1)),
NULL);
} else {
// we'll just have to assume int, i don't feel like checking
if (this->format == SND_PCM_FORMAT_MU_LAW) {
law = 1;
width = 8;
sign = FALSE;
endianness = 0;
} else if (this->format == SND_PCM_FORMAT_A_LAW) {
law = 2;
width = 8;
sign = FALSE;
endianness = 0;
} else {
law = 0;
if (this->format == SND_PCM_FORMAT_S8) {
width = 8;
sign = TRUE;
endianness = 0;
} else if (this->format == SND_PCM_FORMAT_U8) {
width = 8;
sign = FALSE;
endianness = 0;
} else if (this->format == SND_PCM_FORMAT_S16_LE) {
width = 16;
sign = TRUE;
endianness = G_LITTLE_ENDIAN;
} else if (this->format == SND_PCM_FORMAT_S16_BE) {
width = 16;
sign = TRUE;
endianness = G_BIG_ENDIAN;
} else if (this->format == SND_PCM_FORMAT_U16_LE) {
width = 16;
sign = FALSE;
endianness = G_LITTLE_ENDIAN;
} else if (this->format == SND_PCM_FORMAT_U16_BE) {
width = 16;
sign = FALSE;
endianness = G_BIG_ENDIAN;
} else if (this->format == SND_PCM_FORMAT_S24_LE) {
width = 24;
sign = TRUE;
endianness = G_LITTLE_ENDIAN;
} else if (this->format == SND_PCM_FORMAT_S24_BE) {
width = 24;
sign = TRUE;
endianness = G_BIG_ENDIAN;
} else if (this->format == SND_PCM_FORMAT_U24_LE) {
width = 24;
sign = FALSE;
endianness = G_LITTLE_ENDIAN;
} else if (this->format == SND_PCM_FORMAT_U24_BE) {
width = 24;
sign = FALSE;
endianness = G_BIG_ENDIAN;
} else if (this->format == SND_PCM_FORMAT_S32_LE) {
width = 32;
sign = TRUE;
endianness = G_LITTLE_ENDIAN;
} else if (this->format == SND_PCM_FORMAT_S32_BE) {
width = 32;
sign = TRUE;
endianness = G_BIG_ENDIAN;
} else if (this->format == SND_PCM_FORMAT_U32_LE) {
width = 32;
sign = FALSE;
endianness = G_LITTLE_ENDIAN;
} else if (this->format == SND_PCM_FORMAT_U32_BE) {
width = 32;
sign = FALSE;
endianness = G_BIG_ENDIAN;
} else {
g_error ("what is going on here?");
return NULL;
}
}
depth = width;
props = gst_props_new ("format", GST_PROPS_STRING ("int"),
"rate", GST_PROPS_INT (this->rate),
"channels", GST_PROPS_INT ((this->data_interleaved ? this->channels : 1)),
"law", GST_PROPS_INT (law),
"endianness", GST_PROPS_INT (endianness),
"signed", GST_PROPS_BOOLEAN (sign),
"width", GST_PROPS_INT (width),
"depth", GST_PROPS_INT (depth),
NULL);
}
return gst_caps_new ("alsasrc", "audio/raw", props);
}
/*
* Negotiates the caps, "borrowed" from gstosssink.c
*/
GstPadNegotiateReturn
gst_alsa_negotiate(GstPad *pad, GstCaps **caps, gpointer *user_data)
{
GstAlsa *this;
gboolean need_mmap;
g_return_val_if_fail (pad != NULL, GST_PAD_NEGOTIATE_FAIL);
g_return_val_if_fail (GST_IS_PAD (pad), GST_PAD_NEGOTIATE_FAIL);
this = GST_ALSA(gst_pad_get_parent(pad));
// we decide
if (user_data == NULL) {
*caps = NULL;
return GST_PAD_NEGOTIATE_TRY;
}
// have we got caps?
else if (*caps) {
if (this->handle == NULL)
return GST_PAD_NEGOTIATE_FAIL;
if (gst_alsa_parse_caps(this, *caps)) {
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_NEGOTIATE_FAIL;
if (!gst_alsa_start_audio(this))
return GST_PAD_NEGOTIATE_FAIL;
if (need_mmap && !gst_alsa_get_channel_addresses(this))
return GST_PAD_NEGOTIATE_FAIL;
return GST_PAD_NEGOTIATE_AGREE;
}
return GST_PAD_NEGOTIATE_FAIL;
}
return GST_PAD_NEGOTIATE_FAIL;
}
/* shamelessly stolen from pbd's audioengine. thanks, paul! */
static void
gst_alsa_loop (GstElement *element)
{
struct pollfd pfd;
gboolean xrun_detected;
guint32 i;
GstAlsa *this = GST_ALSA(element);
g_return_if_fail(this != NULL);
snd_pcm_poll_descriptors (this->handle, &pfd, 1);
if (this->stream == SND_PCM_STREAM_PLAYBACK) {
pfd.events = POLLOUT | POLLERR;
} else {
pfd.events = POLLIN | POLLERR;
}
do {
if (poll (&pfd, 1, 1000) < 0) {
if (errno == EINTR) {
/* this happens mostly when run
* under gdb, or when exiting due to a signal */
g_print ("EINTR\n");
continue;
}
g_warning("poll call failed (%s)", strerror(errno));
return;
}
if (pfd.revents & POLLERR) {
g_warning("alsa: poll reports error.");
return;
}
if (pfd.revents == 0) {
g_print ("poll on alsa %s device \"%s\" timed out\n",
this->stream==SND_PCM_STREAM_CAPTURE ? "capture" : "playback",
this->device);
/* timed out, such as when the device is paused */
continue;
}
xrun_detected = FALSE;
this->avail = snd_pcm_avail_update (this->handle);
// g_print ("snd_pcm_avail_update() = %d\n", this->avail);
if (this->avail < 0) {
if (this->avail == -EPIPE) {
xrun_detected = TRUE;
} else {
g_warning("unknown ALSA avail_update return value (%d)",
(int)this->avail);
return;
}
}
/* pretty sophisticated eh? */
if (xrun_detected)
g_warning ("xrun detected");
/* we need to loop here because the available bytes might not be
* contiguous */
while (this->avail) {
/* changes this->avail, as a side effect */
if (!gst_alsa_get_channel_addresses (this) < 0) {
g_error("could not get channels");
return;
}
if (this->mute && this->stream == SND_PCM_STREAM_PLAYBACK) {
for (i = 0; i < this->channels; i++) {
if (this->mute & (1<<i)) {
gst_alsa_sink_silence_on_channel (this, i, this->buffer_frames);
}
}
}
if (!this->process(this, this->avail)) {
g_warning("alsa: something happened while processing audio");
return;
}
/* we could have released the mmap regions on a state change */
if (this->mmap_open)
gst_alsa_release_channel_addresses(this);
}
gst_element_yield (element);
} while (TRUE);
}
static gboolean
gst_alsa_src_process (GstAlsa *this, snd_pcm_uframes_t frames)
{
GstBuffer *buf;
GList *l;
GstAlsaPad *pad = NULL;
GstCaps *caps;
gint unit;
// gint i=0;
static gboolean caps_set = FALSE;
if (!caps_set) {
/* let's get on the caps-setting merry-go-round! */
caps = gst_alsa_caps(this);
l = this->pads;
while (l) {
if (!gst_pad_set_caps (GST_ALSA_PAD(l)->pad, caps)) {
g_print ("DANGER WILL ROBINSON!\n");
sleep(1);
return FALSE;
}
l = l->next;
}
caps_set = TRUE;
}
unit = this->sample_bytes * (this->data_interleaved ? this->channels : 1);
while (frames) {
// g_print ("(%d) frames to process: %d\n", i++, frames);
l = this->pads;
while (l) {
pad = GST_ALSA_PAD(l);
if (!pad->buf) {
pad->buf = g_malloc(this->period_frames * unit);
// g_print ("created buffer %p of size %d\n", pad->buf, this->period_frames * unit);
}
/*
g_print ("pad->buf = %p, offset = %d\n", pad->buf, pad->offset);
g_print ("about to memcpy(%p, %p, %d)\n",
pad->buf + pad->offset * unit,
pad->access_addr,
MIN(frames, this->period_frames - pad->offset) * unit);
*/
memcpy(pad->buf + pad->offset * unit,
pad->access_addr,
MIN(frames, this->period_frames - pad->offset) * unit);
pad->offset += MIN(frames, this->period_frames - pad->offset);
if (pad->offset >= this->period_frames) {
if (pad->offset > this->period_frames)
G_BREAKPOINT();
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;
}
frames -= MIN(frames, this->period_frames - pad->offset); // shouldn't
// matter which pad, in theory (tm)
}
return TRUE;
}
static gboolean
gst_alsa_sink_process (GstAlsa *this, snd_pcm_uframes_t frames)
{
guint8 *peeked;
guint32 len, avail;
GstEvent *event = NULL;
GList *l;
/* this is necessary 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' only.
* */
if (!this->sample_bytes) {
if (!GST_ALSA_PAD(this->pads)->bs)
GST_ALSA_PAD(this->pads)->bs = gst_bytestream_new(GST_ALSA_PAD(this->pads)->pad);
if (!(peeked = gst_bytestream_peek_bytes(GST_ALSA_PAD(this->pads)->bs, frames))) {
g_warning("initial pull on pad %s returned NULL", GST_OBJECT_NAME(GST_ALSA_PAD(this->pads)->pad));
gst_element_set_state(GST_ELEMENT(this), GST_STATE_PAUSED);
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;
l = this->pads;
while (l) {
if (!GST_ALSA_PAD(this->pads)->bs)
GST_ALSA_PAD(this->pads)->bs = gst_bytestream_new(GST_ALSA_PAD(this->pads)->pad);
if (!(peeked = gst_bytestream_peek_bytes(GST_ALSA_PAD(this->pads)->bs, len))) {
gst_bytestream_get_status(GST_ALSA_PAD(this->pads)->bs, &avail, &event);
if (event) {
g_warning("got an event on alsasink");
if (GST_EVENT_TYPE(event) == GST_EVENT_EOS) {
/* really, we should just cut this pad out of the graph. let
* me know when this is needed ;)
* also, for sample accuracy etc, we should play avail
* bytes, but hey. */
gst_element_set_eos(GST_ELEMENT(this));
gst_event_free(event);
return TRUE;
}
} else {
/* the element at the top of the chain did not emit an eos
* event. this is a Bug(tm) */
g_assert_not_reached();
}
}
memcpy(GST_ALSA_PAD(this->pads)->access_addr, peeked, len);
gst_bytestream_flush(GST_ALSA_PAD(this->pads)->bs, len);
l=l->next;
}
return TRUE;
}
/* 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);
g_print("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;
}
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) {
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;
}
if (!this->rate)
this->rate = snd_pcm_hw_params_get_rate(hw_param, 0);
if (!this->format)
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, ~0U);
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;
}
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);
if (this->handle)
gst_alsa_close_audio(this);
g_print("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", 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", 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;
guint32 chn;
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;
}
if (this->stream == SND_PCM_STREAM_PLAYBACK) {
for (chn = 0; chn < this->channels; chn++) {
gst_alsa_sink_silence_on_channel (this, chn, this->buffer_frames);
}
}
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)
{
// gint err;
g_return_if_fail(this != NULL);
g_return_if_fail(this->handle != NULL);
/* if ((err = snd_pcm_drop (this->handle)) < 0) {
g_warning("channel flush for failed: %s", snd_strerror (err));
return;
} */
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;
GList *l;
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\n", (int)this->avail);
// g_print ("snd_pcm_mmap_begin() sets avail = %d\n", this->avail);
l = this->pads;
while (l) {
a = &this->mmap_areas[GST_ALSA_PAD(l)->channel > 0 ?
GST_ALSA_PAD(l)->channel-1 : 0];
GST_ALSA_PAD(l)->access_addr = (char *) a->addr + ((a->first + a->step *
this->offset) / 8);
l = l->next;
}
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;
GList *l;
g_return_if_fail (this->mmap_open == TRUE);
GST_DEBUG(0, "releasing mmap'd data region: %d frames\n", (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;
}
l = this->pads;
while (l) {
GST_ALSA_PAD(l)->access_addr = NULL;
l = l->next;
}
for (i=0; i<this->channels; i++) {
this->access_addr[i] = NULL;
}
this->mmap_open = FALSE;
this->avail=0;
}
static void
gst_alsa_sink_silence_on_channel (GstAlsa *this, guint32 chn, guint32 nframes)
{
if (this->access_interleaved) {
memset_interleave
(this->access_addr[chn],
0, nframes * this->sample_bytes,
this->interleave_unit,
this->interleave_skip);
} else {
memset (this->access_addr[chn], 0, nframes * this->sample_bytes);
}
// mark_channel_done (chn);
}
/* taken directly from paul davis' memops.cc */
static void
memset_interleave (char *dst, char val, unsigned int bytes,
unsigned int unit_bytes,
unsigned int skip_bytes)
{
switch (unit_bytes) {
case 1:
while (bytes--) {
*dst = val;
dst += skip_bytes;
}
break;
case 2:
while (bytes) {
*((short *) dst) = (short) val;
dst += skip_bytes;
bytes -= 2;
}
break;
case 4:
while (bytes) {
*((int *) dst) = (int) val;
dst += skip_bytes;
bytes -= 4;
}
break;
}
}
static gboolean
plugin_init (GModule *module, GstPlugin *plugin)
{
GstElementFactory *factory;
if (!gst_library_load ("gstbytestream")) {
gst_info("alsa: could not load support library: 'gstbytestream'\n");
return FALSE;
}
factory = gst_elementfactory_new ("alsasrc", GST_TYPE_ALSA_SRC, &gst_alsa_src_details);
g_return_val_if_fail (factory != NULL, FALSE);
gst_elementfactory_add_padtemplate (factory, gst_alsa_src_pad_factory());
gst_elementfactory_add_padtemplate (factory, gst_alsa_src_request_pad_factory());
gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));
factory = gst_elementfactory_new ("alsasink", GST_TYPE_ALSA_SINK, &gst_alsa_sink_details);
g_return_val_if_fail (factory != NULL, FALSE);
gst_elementfactory_add_padtemplate (factory, gst_alsa_sink_pad_factory());
gst_elementfactory_add_padtemplate (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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