gsta2dpsink.c

这是Linux环境下的蓝牙源代码

	element_class->change_state = GST_DEBUG_FUNCPTR(
					gst_a2dp_sink_change_state);

	g_object_class_install_property(object_class, PROP_DEVICE,
			g_param_spec_string("device", "Device",
			"Bluetooth remote device address",
			NULL, G_PARAM_READWRITE));

	g_object_class_install_property(object_class, PROP_AUTOCONNECT,
			g_param_spec_boolean("auto-connect", "Auto-connect",
			"Automatically attempt to connect to device",
			DEFAULT_AUTOCONNECT, G_PARAM_READWRITE));

	GST_DEBUG_CATEGORY_INIT(gst_a2dp_sink_debug, "a2dpsink", 0,
				"A2DP sink element");
}

GstCaps *gst_a2dp_sink_get_device_caps(GstA2dpSink *self)
{
	return gst_avdtp_sink_get_device_caps(self->sink);
}

static GstCaps *gst_a2dp_sink_get_caps(GstPad *pad)
{
	GstCaps *caps;
	GstCaps *caps_aux;
	GstA2dpSink *self = GST_A2DP_SINK(GST_PAD_PARENT(pad));

	if (self->sink == NULL) {
		GST_DEBUG_OBJECT(self, "a2dpsink isn't initialized "
			"returning template caps");
		caps = gst_static_pad_template_get_caps(
				&gst_a2dp_sink_factory);
	} else {
		GST_LOG_OBJECT(self, "Getting device caps");
		caps = gst_a2dp_sink_get_device_caps(self);
		if (caps == NULL)
			caps = gst_static_pad_template_get_caps(
                                &gst_a2dp_sink_factory);
	}
	caps_aux = gst_caps_copy(caps);
	g_object_set(self->capsfilter, "caps", caps_aux, NULL);
	gst_caps_unref(caps_aux);
	return caps;
}

static gboolean gst_a2dp_sink_init_avdtp_sink(GstA2dpSink *self)
{
	GstElement *sink;

	/* check if we don't need a new sink */
	if (self->sink_is_in_bin)
		return TRUE;

	if (self->sink == NULL)
		sink = gst_element_factory_make("avdtpsink", "avdtpsink");
	else
		sink = GST_ELEMENT(self->sink);

	if (sink == NULL) {
		GST_ERROR_OBJECT(self, "Couldn't create avdtpsink");
		return FALSE;
	}

	if (!gst_bin_add(GST_BIN(self), sink)) {
		GST_ERROR_OBJECT(self, "failed to add avdtpsink "
			"to the bin");
		goto cleanup_and_fail;
	}

	if (gst_element_set_state(sink, GST_STATE_READY) ==
			GST_STATE_CHANGE_FAILURE) {
		GST_ERROR_OBJECT(self, "avdtpsink failed to go to ready");
		goto remove_element_and_fail;
	}

	if (!gst_element_link(GST_ELEMENT(self->rtp), sink)) {
		GST_ERROR_OBJECT(self, "couldn't link rtpsbcpay "
			"to avdtpsink");
		goto remove_element_and_fail;
	}

	self->sink = GST_AVDTP_SINK(sink);
	self->sink_is_in_bin = TRUE;
	g_object_set(G_OBJECT(self->sink), "device", self->device, NULL);

	gst_element_set_state(sink, GST_STATE_PAUSED);

	return TRUE;

remove_element_and_fail:
	gst_element_set_state (sink, GST_STATE_NULL);
	gst_bin_remove(GST_BIN(self), sink);
	return FALSE;

cleanup_and_fail:
	if (sink != NULL)
		g_object_unref(G_OBJECT(sink));

	return FALSE;
}

static gboolean gst_a2dp_sink_init_rtp_sbc_element(GstA2dpSink *self)
{
	GstElement *rtppay;

	/* if we already have a rtp, we don't need a new one */
	if (self->rtp != NULL)
		return TRUE;

	rtppay = gst_a2dp_sink_init_element(self, "rtpsbcpay", "rtp",
						self->capsfilter);
	if (rtppay == NULL)
		return FALSE;

	self->rtp = GST_BASE_RTP_PAYLOAD(rtppay);
	g_object_set(G_OBJECT(self->rtp), "min-frames", -1, NULL);

	gst_element_set_state(rtppay, GST_STATE_PAUSED);

	return TRUE;
}

static gboolean gst_a2dp_sink_init_rtp_mpeg_element(GstA2dpSink *self)
{
	GstElement *rtppay;

	/* check if we don't need a new rtp */
	if (self->rtp)
		return TRUE;

	GST_LOG_OBJECT(self, "Initializing rtp mpeg element");
	/* if capsfilter is not created then we can't have our rtp element */
	if (self->capsfilter == NULL)
		return FALSE;

	rtppay = gst_a2dp_sink_init_element(self, "rtpmpapay", "rtp",
					self->capsfilter);
	if (rtppay == NULL)
		return FALSE;

	self->rtp = GST_BASE_RTP_PAYLOAD(rtppay);

	gst_element_set_state(rtppay, GST_STATE_PAUSED);

	return TRUE;
}

static gboolean gst_a2dp_sink_init_dynamic_elements(GstA2dpSink *self,
						GstCaps *caps)
{
	GstStructure *structure;
	GstEvent *event;
	GstPad *capsfilterpad;
	gboolean crc;
	gchar *mode = NULL;

	structure = gst_caps_get_structure(caps, 0);

	/* before everything we need to remove fakesink */
	gst_a2dp_sink_remove_fakesink(self);

	/* first, we need to create our rtp payloader */
	if (gst_structure_has_name(structure, "audio/x-sbc")) {
		GST_LOG_OBJECT(self, "sbc media received");
		if (!gst_a2dp_sink_init_rtp_sbc_element(self))
			return FALSE;
	} else if (gst_structure_has_name(structure, "audio/mpeg")) {
		GST_LOG_OBJECT(self, "mp3 media received");
		if (!gst_a2dp_sink_init_rtp_mpeg_element(self))
			return FALSE;
	} else {
		GST_ERROR_OBJECT(self, "Unexpected media type");
		return FALSE;
	}

	if (!gst_a2dp_sink_init_avdtp_sink(self))
		return FALSE;

	/* check if we should push the taglist FIXME should we push this?
	 * we can send the tags directly if needed */
	if (self->taglist != NULL &&
			gst_structure_has_name(structure, "audio/mpeg")) {

		event = gst_event_new_tag(self->taglist);

		/* send directly the crc */
		if (gst_tag_list_get_boolean(self->taglist, "has-crc", &crc))
			gst_avdtp_sink_set_crc(self->sink, crc);

		if (gst_tag_list_get_string(self->taglist, "channel-mode",
				&mode))
			gst_avdtp_sink_set_channel_mode(self->sink, mode);

		capsfilterpad = gst_ghost_pad_get_target(self->ghostpad);
		gst_pad_send_event(capsfilterpad, event);
		self->taglist = NULL;
		g_free(mode);
	}

	if (!gst_avdtp_sink_set_device_caps(self->sink, caps))
		return FALSE;

	g_object_set(G_OBJECT(self->rtp), "mtu",
		gst_avdtp_sink_get_link_mtu(self->sink), NULL);

	/* we forward our new segment here if we have one */
	if (self->newseg_event) {
		gst_pad_send_event(GST_BASE_RTP_PAYLOAD_SINKPAD(self->rtp),
					self->newseg_event);
		self->newseg_event = NULL;
	}

	return TRUE;
}

static gboolean gst_a2dp_sink_set_caps(GstPad *pad, GstCaps *caps)
{
	GstA2dpSink *self;

	self = GST_A2DP_SINK(GST_PAD_PARENT(pad));
	GST_INFO_OBJECT(self, "setting caps");

	/* now we know the caps */
	gst_a2dp_sink_init_dynamic_elements(self, caps);

	return self->ghostpad_setcapsfunc(GST_PAD(self->ghostpad), caps);
}

/* used for catching newsegment events while we don't have a sink, for
 * later forwarding it to the sink */
static gboolean gst_a2dp_sink_handle_event(GstPad *pad, GstEvent *event)
{
	GstA2dpSink *self;
	GstTagList *taglist = NULL;
	GstObject *parent;

	self = GST_A2DP_SINK(GST_PAD_PARENT(pad));
	parent = gst_element_get_parent(GST_ELEMENT(self->sink));

	if (GST_EVENT_TYPE(event) == GST_EVENT_NEWSEGMENT &&
			parent != GST_OBJECT_CAST(self)) {
		if (self->newseg_event != NULL)
			gst_event_unref(self->newseg_event);
		self->newseg_event = gst_event_ref(event);

	} else if (GST_EVENT_TYPE(event) == GST_EVENT_TAG &&
			parent != GST_OBJECT_CAST(self)) {
		if (self->taglist == NULL)
			gst_event_parse_tag(event, &self->taglist);
		else {
			gst_event_parse_tag(event, &taglist);
			gst_tag_list_insert(self->taglist, taglist,
					GST_TAG_MERGE_REPLACE);
		}
	}

	if (parent != NULL)
		gst_object_unref(GST_OBJECT(parent));

	return self->ghostpad_eventfunc(GST_PAD(self->ghostpad), event);
}

static gboolean gst_a2dp_sink_init_caps_filter(GstA2dpSink *self)
{
	GstElement *element;

	element = gst_element_factory_make("capsfilter", "filter");
	if (element == NULL)
		goto failed;

	if (!gst_bin_add(GST_BIN(self), element))
		goto failed;

	self->capsfilter = element;
	return TRUE;

failed:
	GST_ERROR_OBJECT(self, "Failed to initialize caps filter");
	return FALSE;
}

static gboolean gst_a2dp_sink_init_fakesink(GstA2dpSink *self)
{
	if (self->fakesink != NULL)
		return TRUE;

	g_mutex_lock (self->cb_mutex);
	self->fakesink = gst_a2dp_sink_init_element(self, "fakesink",
			"fakesink", self->capsfilter);
	g_mutex_unlock (self->cb_mutex);

	if (!self->fakesink)
		return FALSE;

	return TRUE;
}

static gboolean gst_a2dp_sink_remove_fakesink(GstA2dpSink *self)
{
	g_mutex_lock(self->cb_mutex);

	if (self->fakesink != NULL) {
		gst_element_set_locked_state(self->fakesink, TRUE);
		gst_element_set_state(self->fakesink, GST_STATE_NULL);

		gst_bin_remove(GST_BIN(self), self->fakesink);
		self->fakesink = NULL;
	}

	g_mutex_unlock(self->cb_mutex);

	return TRUE;
}

static void gst_a2dp_sink_init(GstA2dpSink *self,
			GstA2dpSinkClass *klass)
{
	self->sink = NULL;
	self->fakesink = NULL;
	self->rtp = NULL;
	self->device = NULL;
	self->autoconnect = DEFAULT_AUTOCONNECT;
	self->capsfilter = NULL;
	self->newseg_event = NULL;
	self->taglist = NULL;
	self->ghostpad = NULL;
	self->sink_is_in_bin = FALSE;

	self->cb_mutex = g_mutex_new();

	/* we initialize our capsfilter */
	gst_a2dp_sink_init_caps_filter(self);
	g_object_set(self->capsfilter, "caps",
		gst_static_pad_template_get_caps(&gst_a2dp_sink_factory),
		NULL);

	gst_a2dp_sink_init_fakesink(self);

	gst_a2dp_sink_init_ghost_pad(self);

}

gboolean gst_a2dp_sink_plugin_init (GstPlugin * plugin)
{
	return gst_element_register (plugin, "a2dpsink",
			GST_RANK_PRIMARY, GST_TYPE_A2DP_SINK);
}