diff --git a/spa/include/spa/param/param.h b/spa/include/spa/param/param.h
index e33382aa7..7bd2291e3 100644
--- a/spa/include/spa/param/param.h
+++ b/spa/include/spa/param/param.h
@@ -37,6 +37,7 @@ enum spa_param_type {
 	SPA_PARAM_Buffers,		/**< buffer configurations */
 	SPA_PARAM_Meta,			/**< allowed metadata for buffers */
 	SPA_PARAM_IO,			/**< configurable IO areas */
+	SPA_PARAM_Profile,		/**< port profile configuration */
 };
 
 /** Properties for SPA_TYPE_OBJECT_ParamList */
@@ -69,6 +70,13 @@ enum spa_param_io {
 	SPA_PARAM_IO_size,	/**< size of the io area */
 };
 
+/** properties for SPA_TYPE_OBJECT_ParamProfile */
+enum spa_param_profile {
+	SPA_PARAM_PROFILE_START,	/**< object id, one of enum spa_param_type */
+	SPA_PARAM_PROFILE_direction,	/**< direction, input/output */
+	SPA_PARAM_PROFILE_format,	/**< profile format specification */
+};
+
 #ifdef __cplusplus
 }  /* extern "C" */
 #endif
diff --git a/spa/include/spa/param/type-info.h b/spa/include/spa/param/type-info.h
index a9e4f62d1..512fa578b 100644
--- a/spa/include/spa/param/type-info.h
+++ b/spa/include/spa/param/type-info.h
@@ -43,6 +43,7 @@ static const struct spa_type_info spa_type_param[] = {
 	{ SPA_PARAM_Buffers, SPA_TYPE_PARAM_ID_BASE "Buffers", SPA_TYPE_Int, },
 	{ SPA_PARAM_Meta, SPA_TYPE_PARAM_ID_BASE "Meta", SPA_TYPE_Int, },
 	{ SPA_PARAM_IO, SPA_TYPE_PARAM_ID_BASE "IO", SPA_TYPE_Int, },
+	{ SPA_PARAM_Profile, SPA_TYPE_PARAM_ID_BASE "Profile", SPA_TYPE_Int, },
 	{ 0, NULL, },
 };
 
@@ -250,6 +251,16 @@ static const struct spa_type_info spa_type_param_buffers[] = {
 	{ 0, NULL, },
 };
 
+#define SPA_TYPE_PARAM__Profile		SPA_TYPE_PARAM_BASE "Profile"
+#define SPA_TYPE_PARAM_PROFILE_BASE	SPA_TYPE_PARAM__Profile ":"
+
+static const struct spa_type_info spa_type_param_profile[] = {
+	{ SPA_PARAM_PROFILE_START, SPA_TYPE_PARAM_PROFILE_BASE, SPA_TYPE_Id, spa_type_param, },
+	{ SPA_PARAM_PROFILE_direction, SPA_TYPE_PARAM_PROFILE_BASE "direction",  SPA_TYPE_Id, spa_type_direction },
+	{ SPA_PARAM_PROFILE_format, SPA_TYPE_PARAM_PROFILE_BASE "format",  SPA_TYPE_Object, NULL, },
+	{ 0, NULL, },
+};
+
 #ifdef __cplusplus
 }  /* extern "C" */
 #endif
diff --git a/spa/include/spa/utils/type-info.h b/spa/include/spa/utils/type-info.h
index 44f231934..76bbe80cf 100644
--- a/spa/include/spa/utils/type-info.h
+++ b/spa/include/spa/utils/type-info.h
@@ -71,6 +71,18 @@ struct spa_type_info {
 #define SPA_TYPE__Command			SPA_TYPE_OBJECT_BASE "Command"
 #define SPA_TYPE_COMMAND_BASE			SPA_TYPE__Command ":"
 
+#include <spa/utils/type.h>
+
+/* base for parameter object enumerations */
+#define SPA_TYPE__Direction		SPA_TYPE_ENUM_BASE "Direction"
+#define SPA_TYPE_DIRECTION_BASE		SPA_TYPE__Direction ":"
+
+static const struct spa_type_info spa_type_direction[] = {
+	{ SPA_DIRECTION_INPUT, SPA_TYPE_DIRECTION_BASE "Input", SPA_TYPE_Int,   },
+	{ SPA_DIRECTION_OUTPUT, SPA_TYPE_DIRECTION_BASE "Output", SPA_TYPE_Int,   },
+	{ 0, NULL, }
+};
+
 #include <spa/monitor/type-info.h>
 #include <spa/node/type-info.h>
 #include <spa/param/type-info.h>
@@ -147,6 +159,7 @@ static const struct spa_type_info spa_types[] = {
 	{ SPA_TYPE_OBJECT_ParamBuffers, SPA_TYPE_PARAM__Buffers, SPA_TYPE_Object, spa_type_param_buffers, },
 	{ SPA_TYPE_OBJECT_ParamMeta, SPA_TYPE_PARAM__Meta, SPA_TYPE_Object, spa_type_param_meta },
 	{ SPA_TYPE_OBJECT_ParamIO, SPA_TYPE_PARAM__IO, SPA_TYPE_Object, spa_type_param_io },
+	{ SPA_TYPE_OBJECT_ParamProfile, SPA_TYPE_PARAM__Profile, SPA_TYPE_Object, spa_type_param_profile },
 
 	{ 0, NULL, }
 };
diff --git a/spa/include/spa/utils/type.h b/spa/include/spa/utils/type.h
index c2e5b09cf..6c3e67f68 100644
--- a/spa/include/spa/utils/type.h
+++ b/spa/include/spa/utils/type.h
@@ -89,6 +89,7 @@ enum {
 	SPA_TYPE_OBJECT_ParamBuffers,
 	SPA_TYPE_OBJECT_ParamMeta,
 	SPA_TYPE_OBJECT_ParamIO,
+	SPA_TYPE_OBJECT_ParamProfile,
 
 	/* vendor extensions */
 	SPA_TYPE_VENDOR_PipeWire	= 0x02000000,
diff --git a/spa/plugins/audioconvert/audioconvert.c b/spa/plugins/audioconvert/audioconvert.c
index 7c616e44b..777e111f8 100644
--- a/spa/plugins/audioconvert/audioconvert.c
+++ b/spa/plugins/audioconvert/audioconvert.c
@@ -411,7 +411,40 @@ static int impl_node_enum_params(struct spa_node *node,
 static int impl_node_set_param(struct spa_node *node, uint32_t id, uint32_t flags,
 			       const struct spa_pod *param)
 {
-	return -ENOTSUP;
+	int res = 0;
+	struct impl *this;
+
+	spa_return_val_if_fail(node != NULL, -EINVAL);
+
+	this = SPA_CONTAINER_OF(node, struct impl, node);
+
+	switch (id) {
+	case SPA_PARAM_Profile:
+	{
+		enum spa_direction direction;
+
+		if (spa_pod_object_parse(param,
+				":", SPA_PARAM_PROFILE_direction, "I", &direction,
+				NULL) < 0)
+			return -EINVAL;
+
+		switch (direction) {
+		case SPA_DIRECTION_INPUT:
+		case SPA_DIRECTION_OUTPUT:
+			res = spa_node_set_param(this->fmt[direction],
+					id, flags, param);
+			break;
+		default:
+			res = -EINVAL;
+			break;
+		}
+		break;
+	}
+	default:
+		res = -ENOTSUP;
+		break;
+	}
+	return res;
 }
 
 static int impl_node_send_command(struct spa_node *node, const struct spa_command *command)
diff --git a/spa/plugins/audioconvert/merger.c b/spa/plugins/audioconvert/merger.c
index 3e3e8f876..4cf975632 100644
--- a/spa/plugins/audioconvert/merger.c
+++ b/spa/plugins/audioconvert/merger.c
@@ -30,10 +30,12 @@
 #include <spa/param/param.h>
 #include <spa/pod/filter.h>
 #include <spa/debug/types.h>
+#include <spa/debug/mem.h>
 
 #define NAME "merger"
 
-#define DEFAULT_RATE	48000
+#define DEFAULT_RATE		48000
+#define DEFAULT_CHANNELS	2
 
 #define MAX_SAMPLES	1024
 #define MAX_BUFFERS	64
@@ -47,7 +49,6 @@ struct buffer {
 };
 
 struct port {
-	bool valid;
 	uint32_t id;
 
 	struct spa_io_buffers *io;
@@ -56,6 +57,7 @@ struct port {
 	struct spa_port_info info;
 	struct spa_dict info_props;
 	struct spa_dict_item info_props_items[2];
+	char position[8];
 
 	bool have_format;
 	struct spa_audio_info format;
@@ -80,28 +82,48 @@ struct impl {
 	void *user_data;
 
 	int port_count;
-	int last_port;
 	struct port in_ports[MAX_PORTS];
 	struct port out_ports[1];
 
-	int n_formats;
-	bool have_format;
-	struct spa_audio_info format;
-	bool force_rate;
-
 	bool started;
 	convert_func_t convert;
 
 	float empty[MAX_SAMPLES];
 };
 
-#define CHECK_FREE_IN_PORT(this,d,p) ((d) == SPA_DIRECTION_INPUT && (p) < MAX_PORTS && !this->in_ports[(p)].valid)
-#define CHECK_IN_PORT(this,d,p)	     ((d) == SPA_DIRECTION_INPUT && (p) < MAX_PORTS && this->in_ports[(p)].valid)
-#define CHECK_OUT_PORT(this,d,p)      ((d) == SPA_DIRECTION_OUTPUT && (p) == 0)
-#define CHECK_PORT(this,d,p)	      (CHECK_OUT_PORT(this,d,p) || CHECK_IN_PORT (this,d,p))
-#define GET_IN_PORT(this,p)	      (&this->in_ports[p])
-#define GET_OUT_PORT(this,p)	      (&this->out_ports[p])
-#define GET_PORT(this,d,p)	      (d == SPA_DIRECTION_INPUT ? GET_IN_PORT(this,p) : GET_OUT_PORT(this,p))
+#define CHECK_IN_PORT(this,d,p)		((d) == SPA_DIRECTION_INPUT && (p) < this->port_count)
+#define CHECK_OUT_PORT(this,d,p)	((d) == SPA_DIRECTION_OUTPUT && (p) == 0)
+#define CHECK_PORT(this,d,p)		(CHECK_OUT_PORT(this,d,p) || CHECK_IN_PORT (this,d,p))
+#define GET_IN_PORT(this,p)		(&this->in_ports[p])
+#define GET_OUT_PORT(this,p)		(&this->out_ports[p])
+#define GET_PORT(this,d,p)		(d == SPA_DIRECTION_INPUT ? GET_IN_PORT(this,p) : GET_OUT_PORT(this,p))
+
+static int init_port(struct impl *this, uint32_t port_id, uint32_t rate, uint32_t position)
+{
+	struct port *port = GET_IN_PORT(this, port_id);
+	port->id = port_id;
+
+	snprintf(port->position, 7, "%s", rindex(spa_type_audio_channel[position].name, ':')+1);
+
+	port->info.flags = SPA_PORT_INFO_FLAG_CAN_USE_BUFFERS;
+	port->info_props_items[0] = SPA_DICT_ITEM_INIT("port.dsp", "32 bit float mono audio");
+	port->info_props_items[1] = SPA_DICT_ITEM_INIT("port.channel", port->position);
+	port->info_props = SPA_DICT_INIT(port->info_props_items, 2);
+	port->info.props = &port->info_props;
+
+	port->n_buffers = 0;
+	port->have_format = false;
+	port->format.media_type = SPA_MEDIA_TYPE_audio;
+	port->format.media_subtype = SPA_MEDIA_SUBTYPE_raw;
+	port->format.info.raw.format = SPA_AUDIO_FORMAT_F32P;
+	port->format.info.raw.rate = rate;
+	port->format.info.raw.channels = 1;
+	port->format.info.raw.position[0] = position;
+
+	spa_log_debug(this->log, NAME " %p: add port %d", this, port_id);
+
+	return 0;
+}
 
 static int impl_node_enum_params(struct spa_node *node,
 				 uint32_t id, uint32_t *index,
@@ -109,13 +131,89 @@ static int impl_node_enum_params(struct spa_node *node,
 				 struct spa_pod **param,
 				 struct spa_pod_builder *builder)
 {
-	return -ENOTSUP;
+	spa_return_val_if_fail(node != NULL, -EINVAL);
+
+	switch (id) {
+	case SPA_PARAM_List:
+	{
+		uint32_t list[] = { SPA_PARAM_Profile };
+
+		if (*index < SPA_N_ELEMENTS(list))
+			param = spa_pod_builder_object(builder,
+					SPA_TYPE_OBJECT_ParamList, id,
+					SPA_PARAM_LIST_id, &SPA_POD_Id(list[*index]),
+					0);
+		else
+			return 0;
+		break;
+	}
+	default:
+		return 0;
+	}
+	(*index)++;
+
+	return 1;
 }
 
 static int impl_node_set_param(struct spa_node *node, uint32_t id, uint32_t flags,
 			       const struct spa_pod *param)
 {
-	return -ENOTSUP;
+	struct impl *this;
+	int res;
+
+	spa_return_val_if_fail(node != NULL, -EINVAL);
+
+	this = SPA_CONTAINER_OF(node, struct impl, node);
+
+	switch (id) {
+	case SPA_PARAM_Profile:
+	{
+		struct spa_audio_info info = { 0, };
+		struct port *port;
+		struct spa_pod *format;
+		int i;
+
+		if (spa_pod_object_parse(param,
+					":", SPA_PARAM_PROFILE_format, "P", &format,
+					NULL) < 0)
+			return -EINVAL;
+
+		if (!SPA_POD_IS_OBJECT_TYPE(format, SPA_TYPE_OBJECT_Format))
+			return -EINVAL;
+
+		if ((res = spa_format_parse(format, &info.media_type, &info.media_subtype)) < 0)
+			return res;
+
+		if (info.media_type != SPA_MEDIA_TYPE_audio ||
+		    info.media_subtype != SPA_MEDIA_SUBTYPE_raw)
+			return -EINVAL;
+
+		if (spa_format_audio_raw_parse(format, &info.info.raw) < 0)
+			return -EINVAL;
+
+		port = GET_OUT_PORT(this, 0);
+		if (port->have_format && memcmp(&port->format, &info, sizeof(info)) == 0)
+			return 0;
+
+		port->have_format = true;
+		port->format = info;
+
+		this->port_count = info.info.raw.channels;
+		for (i = 0; i < this->port_count; i++) {
+			init_port(this, i, info.info.raw.rate,
+					info.info.raw.position[i]);
+		}
+
+		if (this->callbacks && this->callbacks->event)
+			this->callbacks->event(this->user_data,
+				&SPA_NODE_EVENT_INIT(SPA_NODE_EVENT_PortsChanged));
+
+		return 0;
+	}
+	default:
+		return -ENOENT;
+	}
+	return 0;
 }
 
 static int impl_node_send_command(struct spa_node *node, const struct spa_command *command)
@@ -173,7 +271,7 @@ impl_node_get_n_ports(struct spa_node *node,
 	if (n_input_ports)
 		*n_input_ports = this->port_count;
 	if (max_input_ports)
-		*max_input_ports = MAX_PORTS;
+		*max_input_ports = this->port_count;
 	if (n_output_ports)
 		*n_output_ports = 1;
 	if (max_output_ports)
@@ -190,17 +288,16 @@ impl_node_get_port_ids(struct spa_node *node,
 		       uint32_t n_output_ids)
 {
 	struct impl *this;
-	int i, idx;
+	int i;
 
 	spa_return_val_if_fail(node != NULL, -EINVAL);
 
 	this = SPA_CONTAINER_OF(node, struct impl, node);
 
 	if (input_ids) {
-		for (i = 0, idx = 0; i < this->last_port && idx < n_input_ids; i++) {
-			if (this->in_ports[i].valid)
-				input_ids[idx++] = i;
-		}
+		n_input_ids = SPA_MIN(n_input_ids, this->port_count);
+		for (i = 0; i < n_input_ids; i++)
+			input_ids[i] = i;
 	}
 	if (n_output_ids > 0 && output_ids)
 		output_ids[0] = 0;
@@ -210,73 +307,15 @@ impl_node_get_port_ids(struct spa_node *node,
 
 static int impl_node_add_port(struct spa_node *node, enum spa_direction direction, uint32_t port_id)
 {
-	struct impl *this;
-	struct port *port;
-
 	spa_return_val_if_fail(node != NULL, -EINVAL);
-
-	this = SPA_CONTAINER_OF(node, struct impl, node);
-
-	spa_return_val_if_fail(CHECK_FREE_IN_PORT(this, direction, port_id), -EINVAL);
-
-	port = GET_IN_PORT (this, port_id);
-	port->valid = true;
-	port->id = port_id;
-
-	port->info.flags = SPA_PORT_INFO_FLAG_CAN_USE_BUFFERS |
-			   SPA_PORT_INFO_FLAG_REMOVABLE;
-	port->info_props_items[0] = SPA_DICT_ITEM_INIT("port.dsp", "32 bit float mono audio");
-	port->info_props = SPA_DICT_INIT(port->info_props_items, 1);
-	port->info.props = &port->info_props;
-
-	this->port_count++;
-	if (this->last_port <= port_id)
-		this->last_port = port_id + 1;
-
-	port->have_format = false;
-	this->have_format = false;
-
-	spa_log_debug(this->log, NAME " %p: add port %d", this, port_id);
-
-	return 0;
+	return -ENOTSUP;
 }
 
 static int
 impl_node_remove_port(struct spa_node *node, enum spa_direction direction, uint32_t port_id)
 {
-	struct impl *this;
-	struct port *port;
-
 	spa_return_val_if_fail(node != NULL, -EINVAL);
-
-	this = SPA_CONTAINER_OF(node, struct impl, node);
-
-	spa_return_val_if_fail(CHECK_IN_PORT(this, direction, port_id), -EINVAL);
-
-	port = GET_IN_PORT (this, port_id);
-
-	this->port_count--;
-	if (port->have_format) {
-		if (--this->n_formats == 0) {
-			this->have_format = false;
-			this->convert = NULL;
-		}
-	}
-
-	spa_memzero(port, sizeof(struct port));
-
-	if (port_id == this->last_port + 1) {
-		int i;
-
-		for (i = this->last_port; i >= 0; i--)
-			if (GET_IN_PORT (this, i)->valid)
-				break;
-
-		this->last_port = i + 1;
-	}
-	spa_log_debug(this->log, NAME " %p: remove port %d", this, port_id);
-
-	return 0;
+	return -ENOTSUP;
 }
 
 static int
@@ -308,23 +347,21 @@ static int port_enum_formats(struct spa_node *node,
 			     struct spa_pod_builder *builder)
 {
 	struct impl *this = SPA_CONTAINER_OF(node, struct impl, node);
-	void *rate;
+	struct port *port = GET_PORT(this, direction, port_id);
 
 	switch (*index) {
 	case 0:
-		if (this->have_format || this->force_rate) {
-			rate = &SPA_POD_Int(this->format.info.raw.rate);
-		}
-		else {
-			rate = &SPA_POD_CHOICE_RANGE_Int(DEFAULT_RATE, 1, INT32_MAX);
-		}
-
 		if (direction == SPA_DIRECTION_OUTPUT) {
-			*param = spa_pod_builder_object(builder,
-				SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
-				SPA_FORMAT_mediaType,      &SPA_POD_Id(SPA_MEDIA_TYPE_audio),
-				SPA_FORMAT_mediaSubtype,   &SPA_POD_Id(SPA_MEDIA_SUBTYPE_raw),
-				SPA_FORMAT_AUDIO_format,   &SPA_POD_CHOICE_ENUM_Id(13,
+			if (port->have_format) {
+				*param = spa_format_audio_raw_build(builder,
+					SPA_PARAM_EnumFormat, &port->format.info.raw);
+			}
+			else {
+				*param = spa_pod_builder_object(builder,
+					SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
+					SPA_FORMAT_mediaType,      &SPA_POD_Id(SPA_MEDIA_TYPE_audio),
+					SPA_FORMAT_mediaSubtype,   &SPA_POD_Id(SPA_MEDIA_SUBTYPE_raw),
+					SPA_FORMAT_AUDIO_format,   &SPA_POD_CHOICE_ENUM_Id(13,
 								SPA_AUDIO_FORMAT_F32,
 								SPA_AUDIO_FORMAT_F32,
 								SPA_AUDIO_FORMAT_F32P,
@@ -338,19 +375,17 @@ static int port_enum_formats(struct spa_node *node,
 								SPA_AUDIO_FORMAT_S16P,
 								SPA_AUDIO_FORMAT_U8,
 								SPA_AUDIO_FORMAT_U8P),
-				SPA_FORMAT_AUDIO_rate,     rate,
-				SPA_FORMAT_AUDIO_channels, &SPA_POD_Int(this->port_count),
-				0);
+					SPA_FORMAT_AUDIO_rate,     &SPA_POD_CHOICE_RANGE_Int(
+						DEFAULT_RATE, 1, INT32_MAX),
+					SPA_FORMAT_AUDIO_channels, &SPA_POD_CHOICE_RANGE_Int(
+						DEFAULT_CHANNELS, 1, MAX_PORTS),
+					0);
+			}
 		}
 		else {
-			*param = spa_pod_builder_object(builder,
-				SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
-				SPA_FORMAT_mediaType,      &SPA_POD_Id(SPA_MEDIA_TYPE_audio),
-				SPA_FORMAT_mediaSubtype,   &SPA_POD_Id(SPA_MEDIA_SUBTYPE_raw),
-				SPA_FORMAT_AUDIO_format,   &SPA_POD_Id(SPA_AUDIO_FORMAT_F32P),
-				SPA_FORMAT_AUDIO_rate,     rate,
-				SPA_FORMAT_AUDIO_channels, &SPA_POD_Int(1),
-				0);
+			struct port *other = GET_IN_PORT(this, port_id);
+			*param = spa_format_audio_raw_build(builder,
+					SPA_PARAM_EnumFormat, &other->format.info.raw);
 		}
 		break;
 	default:
@@ -387,7 +422,7 @@ impl_node_port_enum_params(struct spa_node *node,
       next:
 	spa_pod_builder_init(&b, buffer, sizeof(buffer));
 
-	spa_log_debug(this->log, NAME " %p: enum param %d %d", this, id, this->have_format);
+	spa_log_debug(this->log, NAME " %p: enum param %d %d", this, id, port->have_format);
 
 	switch (id) {
 	case SPA_PARAM_List:
@@ -486,37 +521,21 @@ static int clear_buffers(struct impl *this, struct port *port)
 	return 0;
 }
 
-static struct port *find_in_port(struct impl *this)
-{
-	int i;
-	struct port *port;
-
-	for (i = 0; i < this->last_port; i++) {
-		port = &this->in_ports[i];
-		if (port->have_format)
-			return port;
-	}
-	return NULL;
-}
-
 static int setup_convert(struct impl *this)
 {
 	const struct conv_info *conv;
-	struct port *inport, *outport;
+	struct port *outport;
 	uint32_t src_fmt, dst_fmt;
 
 	outport = GET_OUT_PORT(this, 0);
-	inport = find_in_port(this);
-	if (inport == NULL || !outport->have_format)
-		return -EINVAL;
 
-	src_fmt = inport->format.info.raw.format;
+	src_fmt = SPA_AUDIO_FORMAT_F32P;
 	dst_fmt = outport->format.info.raw.format;
 
 	spa_log_info(this->log, NAME " %p: %s/%d@%dx%d->%s/%d@%d", this,
 			spa_debug_type_find_name(spa_type_audio_format, src_fmt),
-			inport->format.info.raw.channels,
-			inport->format.info.raw.rate,
+			1,
+			outport->format.info.raw.rate,
 			this->port_count,
 			spa_debug_type_find_name(spa_type_audio_format, dst_fmt),
 			outport->format.info.raw.channels,
@@ -561,13 +580,11 @@ static int port_set_format(struct spa_node *node,
 
 	port = GET_PORT(this, direction, port_id);
 
-	spa_log_debug(this->log, NAME " %p: set format %d", this, this->have_format);
+	spa_log_debug(this->log, NAME " %p: set format", this);
 
 	if (format == NULL) {
 		if (port->have_format) {
 			port->have_format = false;
-			if (--this->n_formats == 0)
-				this->have_format = false;
 			clear_buffers(this, port);
 		}
 	} else {
@@ -583,19 +600,18 @@ static int port_set_format(struct spa_node *node,
 		if (spa_format_audio_raw_parse(format, &info.info.raw) < 0)
 			return -EINVAL;
 
-		if ((this->have_format || this->force_rate) &&
-		    info.info.raw.rate != this->format.info.raw.rate)
-			return -EINVAL;
-
-		if (direction == SPA_DIRECTION_OUTPUT) {
-			if (info.info.raw.channels != this->port_count)
+		if (direction == SPA_DIRECTION_INPUT) {
+			if (info.info.raw.rate != port->format.info.raw.rate)
 				return -EINVAL;
-		} else {
 			if (info.info.raw.format != SPA_AUDIO_FORMAT_F32P)
 				return -EINVAL;
 			if (info.info.raw.channels != 1)
 				return -EINVAL;
 		}
+		else {
+			if (info.info.raw.channels != this->port_count)
+				return -EINVAL;
+		}
 
 		port->format = info;
 		port->stride = calc_width(&info);
@@ -608,16 +624,10 @@ static int port_set_format(struct spa_node *node,
 		}
 		spa_log_debug(this->log, NAME " %p: %d %d %d", this, port_id, port->stride, port->blocks);
 
-		this->have_format = true;
-		this->format = info;
+		if (direction == SPA_DIRECTION_OUTPUT)
+			setup_convert(this);
 
-		if (!port->have_format) {
-			this->n_formats++;
-			port->have_format = true;
-			spa_log_debug(this->log, NAME " %p: set format on port %d", this, port_id);
-		}
-
-		setup_convert(this);
+		port->have_format = true;
 	}
 
 	return 0;
@@ -837,7 +847,7 @@ static int impl_node_process(struct spa_node *node)
 
 	/* produce more output if possible */
 	n_src_datas = 0;
-	for (i = 0; i < this->last_port; i++) {
+	for (i = 0; i < this->port_count; i++) {
 		struct port *inport = GET_IN_PORT(this, i);
 		struct spa_io_buffers *inio;
 
@@ -942,8 +952,6 @@ impl_init(const struct spa_handle_factory *factory,
 	struct impl *this;
 	struct port *port;
 	uint32_t i;
-	const char *str;
-	int rate;
 
 	spa_return_val_if_fail(factory != NULL, -EINVAL);
 	spa_return_val_if_fail(handle != NULL, -EINVAL);
@@ -958,17 +966,9 @@ impl_init(const struct spa_handle_factory *factory,
 			this->log = support[i].data;
 	}
 
-	if ((str = spa_dict_lookup(info, "node.format.rate")))
-		if ((rate = atoi(str)) != 0) {
-			this->format.info.raw.rate = rate;
-			this->force_rate = true;
-		}
-
 	this->node = impl_node;
-	this->have_format = false;
 
 	port = GET_OUT_PORT(this, 0);
-	port->valid = true;
 	port->id = 0;
 	port->info.flags = SPA_PORT_INFO_FLAG_CAN_USE_BUFFERS;
 	spa_list_init(&port->queue);
diff --git a/spa/plugins/audioconvert/splitter.c b/spa/plugins/audioconvert/splitter.c
index e290aa225..2d868e73e 100644
--- a/spa/plugins/audioconvert/splitter.c
+++ b/spa/plugins/audioconvert/splitter.c
@@ -30,10 +30,13 @@
 #include <spa/param/param.h>
 #include <spa/pod/filter.h>
 #include <spa/debug/types.h>
+#include <spa/debug/mem.h>
 
 #define NAME "splitter"
 
-#define DEFAULT_RATE	48000
+#define DEFAULT_RATE		48000
+#define DEFAULT_CHANNELS	2
+#define DEFAULT_MASK		(1LL << SPA_AUDIO_CHANNEL_FL) | (1LL << SPA_AUDIO_CHANNEL_FR)
 
 #define MAX_SAMPLES	1024
 #define MAX_BUFFERS	64
@@ -47,7 +50,6 @@ struct buffer {
 };
 
 struct port {
-	bool valid;
 	uint32_t id;
 
 	struct spa_io_buffers *io;
@@ -56,6 +58,7 @@ struct port {
 	struct spa_port_info info;
 	struct spa_dict info_props;
 	struct spa_dict_item info_props_items[2];
+	char position[8];
 
 	bool have_format;
 	struct spa_audio_info format;
@@ -80,14 +83,8 @@ struct impl {
 	void *user_data;
 
 	struct port in_ports[1];
-	int port_count;
-	int last_port;
 	struct port out_ports[MAX_PORTS];
-
-	int n_formats;
-	bool have_format;
-	struct spa_audio_info format;
-	bool force_rate;
+	int port_count;
 
 	bool started;
 	convert_func_t convert;
@@ -95,13 +92,40 @@ struct impl {
 	float empty[MAX_SAMPLES];
 };
 
-#define CHECK_FREE_OUT_PORT(this,d,p) ((d) == SPA_DIRECTION_OUTPUT && (p) < MAX_PORTS && !this->out_ports[(p)].valid)
-#define CHECK_OUT_PORT(this,d,p)      ((d) == SPA_DIRECTION_OUTPUT && (p) < MAX_PORTS && this->out_ports[(p)].valid)
-#define CHECK_IN_PORT(this,d,p)       ((d) == SPA_DIRECTION_INPUT && (p) == 0)
-#define CHECK_PORT(this,d,p)	      (CHECK_OUT_PORT(this,d,p) || CHECK_IN_PORT (this,d,p))
-#define GET_IN_PORT(this,p)	      (&this->in_ports[p])
-#define GET_OUT_PORT(this,p)	      (&this->out_ports[p])
-#define GET_PORT(this,d,p)	      (d == SPA_DIRECTION_INPUT ? GET_IN_PORT(this,p) : GET_OUT_PORT(this,p))
+#define CHECK_OUT_PORT(this,d,p)	((d) == SPA_DIRECTION_OUTPUT && (p) < this->port_count)
+#define CHECK_IN_PORT(this,d,p)		((d) == SPA_DIRECTION_INPUT && (p) == 0)
+#define CHECK_PORT(this,d,p)		(CHECK_OUT_PORT(this,d,p) || CHECK_IN_PORT (this,d,p))
+#define GET_IN_PORT(this,p)		(&this->in_ports[p])
+#define GET_OUT_PORT(this,p)		(&this->out_ports[p])
+#define GET_PORT(this,d,p)		(d == SPA_DIRECTION_INPUT ? GET_IN_PORT(this,p) : GET_OUT_PORT(this,p))
+
+static int init_port(struct impl *this, uint32_t port_id, uint32_t rate, uint32_t position)
+{
+	struct port *port = GET_OUT_PORT(this, port_id);
+
+	port->id = port_id;
+	port->info.flags = SPA_PORT_INFO_FLAG_CAN_USE_BUFFERS;
+	snprintf(port->position, 7, "%s", rindex(spa_type_audio_channel[position].name, ':')+1);
+	port->info_props_items[0] = SPA_DICT_ITEM_INIT("port.dsp", "32 bit float mono audio");
+	port->info_props_items[1] = SPA_DICT_ITEM_INIT("port.channel", port->position);
+	port->info_props = SPA_DICT_INIT(port->info_props_items, 2);
+	port->info.props = &port->info_props;
+
+	spa_list_init(&port->queue);
+
+	port->n_buffers = 0;
+	port->have_format = false;
+	port->format.media_type = SPA_MEDIA_TYPE_audio;
+	port->format.media_subtype = SPA_MEDIA_SUBTYPE_raw;
+	port->format.info.raw.format = SPA_AUDIO_FORMAT_F32P;
+	port->format.info.raw.rate = rate;
+	port->format.info.raw.channels = 1;
+	port->format.info.raw.position[0] = position;
+
+	spa_log_debug(this->log, NAME " %p: init port %d %s", this, port_id, port->position);
+
+	return 0;
+}
 
 static int impl_node_enum_params(struct spa_node *node,
 				 uint32_t id, uint32_t *index,
@@ -109,13 +133,87 @@ static int impl_node_enum_params(struct spa_node *node,
 				 struct spa_pod **param,
 				 struct spa_pod_builder *builder)
 {
-	return -ENOTSUP;
+	spa_return_val_if_fail(node != NULL, -EINVAL);
+
+	switch (id) {
+	case SPA_PARAM_List:
+	{
+		uint32_t list[] = { SPA_PARAM_Profile };
+
+		if (*index < SPA_N_ELEMENTS(list))
+			param = spa_pod_builder_object(builder,
+					SPA_TYPE_OBJECT_ParamList, id,
+					SPA_PARAM_LIST_id, &SPA_POD_Id(list[*index]),
+					0);
+		else
+			return 0;
+		break;
+	}
+	default:
+		return 0;
+	}
+	(*index)++;
+
+	return 1;
 }
 
 static int impl_node_set_param(struct spa_node *node, uint32_t id, uint32_t flags,
 			       const struct spa_pod *param)
 {
-	return -ENOTSUP;
+	struct impl *this;
+	int res;
+
+	spa_return_val_if_fail(node != NULL, -EINVAL);
+
+	this = SPA_CONTAINER_OF(node, struct impl, node);
+
+	switch (id) {
+	case SPA_PARAM_Profile:
+	{
+		struct port *port;
+		struct spa_audio_info info = { 0, };
+		struct spa_pod *format;
+		int i;
+
+		if (spa_pod_object_parse(param,
+					":", SPA_PARAM_PROFILE_format, "P", &format,
+					NULL) < 0)
+			return -EINVAL;
+
+		if (!SPA_POD_IS_OBJECT_TYPE(format, SPA_TYPE_OBJECT_Format))
+			return -EINVAL;
+
+		if ((res = spa_format_parse(format, &info.media_type, &info.media_subtype)) < 0)
+			return res;
+
+		if (info.media_type != SPA_MEDIA_TYPE_audio ||
+		    info.media_subtype != SPA_MEDIA_SUBTYPE_raw)
+			return -EINVAL;
+
+		if (spa_format_audio_raw_parse(format, &info.info.raw) < 0)
+			return -EINVAL;
+
+		port = GET_IN_PORT(this, 0);
+		if (port->have_format && memcmp(&port->format, &info, sizeof(info)) == 0)
+			return 0;
+
+		this->port_count = info.info.raw.channels;
+		for (i = 0; i < this->port_count; i++) {
+			init_port(this, i, info.info.raw.rate,
+					info.info.raw.position[i]);
+		}
+		port->have_format = true;
+		port->format = info;
+
+		if (this->callbacks && this->callbacks->event)
+			this->callbacks->event(this->user_data,
+				&SPA_NODE_EVENT_INIT(SPA_NODE_EVENT_PortsChanged));
+		return 0;
+	}
+	default:
+		return -ENOENT;
+	}
+	return 0;
 }
 
 static int impl_node_send_command(struct spa_node *node, const struct spa_command *command)
@@ -177,7 +275,7 @@ impl_node_get_n_ports(struct spa_node *node,
 	if (n_output_ports)
 		*n_output_ports = this->port_count;
 	if (max_output_ports)
-		*max_output_ports = MAX_PORTS;
+		*max_output_ports = this->port_count;
 
 	return 0;
 }
@@ -190,7 +288,7 @@ impl_node_get_port_ids(struct spa_node *node,
 		       uint32_t n_output_ids)
 {
 	struct impl *this;
-	int i, idx;
+	int i;
 
 	spa_return_val_if_fail(node != NULL, -EINVAL);
 
@@ -199,86 +297,24 @@ impl_node_get_port_ids(struct spa_node *node,
 	if (n_input_ids > 0 && input_ids)
 		input_ids[0] = 0;
 	if (output_ids) {
-		for (i = 0, idx = 0; i < this->last_port && idx < n_output_ids; i++) {
-			if (this->out_ports[i].valid)
-				output_ids[idx++] = i;
-		}
+		n_output_ids = SPA_MIN(n_output_ids, this->port_count);
+		for (i = 0; i < n_output_ids; i++)
+			output_ids[i] = i;
 	}
 	return 0;
 }
 
 static int impl_node_add_port(struct spa_node *node, enum spa_direction direction, uint32_t port_id)
 {
-	struct impl *this;
-	struct port *port;
-
 	spa_return_val_if_fail(node != NULL, -EINVAL);
-
-	this = SPA_CONTAINER_OF(node, struct impl, node);
-
-	spa_return_val_if_fail(CHECK_FREE_OUT_PORT(this, direction, port_id), -EINVAL);
-
-	port = GET_OUT_PORT (this, port_id);
-	port->valid = true;
-	port->id = port_id;
-
-	port->info.flags = SPA_PORT_INFO_FLAG_CAN_USE_BUFFERS |
-			   SPA_PORT_INFO_FLAG_REMOVABLE;
-
-	port->info_props_items[0] = SPA_DICT_ITEM_INIT("port.dsp", "32 bit float mono audio");
-	port->info_props = SPA_DICT_INIT(port->info_props_items, 1);
-	port->info.props = &port->info_props;
-
-	spa_list_init(&port->queue);
-
-	this->port_count++;
-	if (this->last_port <= port_id)
-		this->last_port = port_id + 1;
-
-	port->have_format = false;
-	this->have_format = false;
-
-	spa_log_debug(this->log, NAME " %p: add port %d", this, port_id);
-
-	return 0;
+	return -ENOTSUP;
 }
 
 static int
 impl_node_remove_port(struct spa_node *node, enum spa_direction direction, uint32_t port_id)
 {
-	struct impl *this;
-	struct port *port;
-
 	spa_return_val_if_fail(node != NULL, -EINVAL);
-
-	this = SPA_CONTAINER_OF(node, struct impl, node);
-
-	spa_return_val_if_fail(CHECK_OUT_PORT(this, direction, port_id), -EINVAL);
-
-	port = GET_OUT_PORT (this, port_id);
-
-	this->port_count--;
-	if (port->have_format) {
-		if (--this->n_formats == 0) {
-			this->have_format = false;
-			this->convert = NULL;
-		}
-	}
-
-	spa_memzero(port, sizeof(struct port));
-
-	if (port_id == this->last_port + 1) {
-		int i;
-
-		for (i = this->last_port; i >= 0; i--)
-			if (GET_OUT_PORT (this, i)->valid)
-				break;
-
-		this->last_port = i + 1;
-	}
-	spa_log_debug(this->log, NAME " %p: remove port %d", this, port_id);
-
-	return 0;
+	return -ENOTSUP;
 }
 
 static int
@@ -311,21 +347,21 @@ static int port_enum_formats(struct spa_node *node,
 			     struct spa_pod_builder *builder)
 {
 	struct impl *this = SPA_CONTAINER_OF(node, struct impl, node);
-	struct spa_pod *prate;
+	struct port *port = GET_PORT(this, direction, port_id);
 
 	switch (*index) {
 	case 0:
-		if (this->have_format || this->force_rate)
-			prate = (struct spa_pod*)&SPA_POD_Int(this->format.info.raw.rate);
-		else
-			prate = (struct spa_pod*)&SPA_POD_CHOICE_RANGE_Int(DEFAULT_RATE, 1, INT32_MAX);
-
 		if (direction == SPA_DIRECTION_INPUT) {
-			*param = spa_pod_builder_object(builder,
-				SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
-				SPA_FORMAT_mediaType,      &SPA_POD_Id(SPA_MEDIA_TYPE_audio),
-				SPA_FORMAT_mediaSubtype,   &SPA_POD_Id(SPA_MEDIA_SUBTYPE_raw),
-				SPA_FORMAT_AUDIO_format,   &SPA_POD_CHOICE_ENUM_Id(18,
+			if (port->have_format) {
+				*param = spa_format_audio_raw_build(builder,
+						SPA_PARAM_EnumFormat, &port->format.info.raw);
+			}
+			else {
+				*param = spa_pod_builder_object(builder,
+					SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
+					SPA_FORMAT_mediaType,      &SPA_POD_Id(SPA_MEDIA_TYPE_audio),
+					SPA_FORMAT_mediaSubtype,   &SPA_POD_Id(SPA_MEDIA_SUBTYPE_raw),
+					SPA_FORMAT_AUDIO_format,   &SPA_POD_CHOICE_ENUM_Id(18,
 								SPA_AUDIO_FORMAT_F32,
 								SPA_AUDIO_FORMAT_F32P,
 								SPA_AUDIO_FORMAT_F32,
@@ -344,19 +380,17 @@ static int port_enum_formats(struct spa_node *node,
 								SPA_AUDIO_FORMAT_S16_OE,
 								SPA_AUDIO_FORMAT_U8P,
 								SPA_AUDIO_FORMAT_U8),
-				SPA_FORMAT_AUDIO_rate,     prate,
-				SPA_FORMAT_AUDIO_channels, &SPA_POD_Int(this->port_count),
-				0);
+					SPA_FORMAT_AUDIO_rate,     &SPA_POD_CHOICE_RANGE_Int(
+							DEFAULT_RATE, 1, INT32_MAX),
+					SPA_FORMAT_AUDIO_channels, &SPA_POD_CHOICE_RANGE_Int(
+							DEFAULT_CHANNELS, 1, MAX_PORTS),
+					0);
+			}
 		}
 		else {
-			*param = spa_pod_builder_object(builder,
-				SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
-				SPA_FORMAT_mediaType,      &SPA_POD_Id(SPA_MEDIA_TYPE_audio),
-				SPA_FORMAT_mediaSubtype,   &SPA_POD_Id(SPA_MEDIA_SUBTYPE_raw),
-				SPA_FORMAT_AUDIO_format,   &SPA_POD_Id(SPA_AUDIO_FORMAT_F32P),
-				SPA_FORMAT_AUDIO_rate,     prate,
-				SPA_FORMAT_AUDIO_channels, &SPA_POD_Int(1),
-				0);
+			struct port *other = GET_OUT_PORT(this, port_id);
+			*param = spa_format_audio_raw_build(builder,
+					SPA_PARAM_EnumFormat, &other->format.info.raw);
 		}
 		break;
 	default:
@@ -393,7 +427,7 @@ impl_node_port_enum_params(struct spa_node *node,
       next:
 	spa_pod_builder_init(&b, buffer, sizeof(buffer));
 
-	spa_log_debug(this->log, NAME " %p: enum param %d %d", this, id, this->have_format);
+	spa_log_debug(this->log, NAME " %p: enum param %d", this, id);
 
 	switch (id) {
 	case SPA_PARAM_List:
@@ -495,40 +529,24 @@ static int clear_buffers(struct impl *this, struct port *port)
 	return 0;
 }
 
-static struct port *find_out_port(struct impl *this)
-{
-	int i;
-	struct port *port;
-
-	for (i = 0; i < this->last_port; i++) {
-		port = GET_OUT_PORT(this, i);
-		if (port->have_format)
-			return port;
-	}
-	return NULL;
-}
-
 static int setup_convert(struct impl *this)
 {
 	const struct conv_info *conv;
-	struct port *inport, *outport;
+	struct port *inport;
 	uint32_t src_fmt, dst_fmt;
 
 	inport = GET_IN_PORT(this, 0);
-	outport = find_out_port(this);
-	if (outport == NULL || !inport->have_format)
-		return -EINVAL;
 
 	src_fmt = inport->format.info.raw.format;
-	dst_fmt = outport->format.info.raw.format;
+	dst_fmt = SPA_AUDIO_FORMAT_F32P;
 
 	spa_log_info(this->log, NAME " %p: %s/%d@%d->%s/%d@%dx%d", this,
 			spa_debug_type_find_name(spa_type_audio_format, src_fmt),
 			inport->format.info.raw.channels,
 			inport->format.info.raw.rate,
 			spa_debug_type_find_name(spa_type_audio_format, dst_fmt),
-			outport->format.info.raw.channels,
-			outport->format.info.raw.rate,
+			1,
+			inport->format.info.raw.rate,
 			this->port_count);
 
 	conv = find_conv_info(src_fmt, dst_fmt, FEATURE_SSE);
@@ -573,13 +591,11 @@ static int port_set_format(struct spa_node *node,
 
 	port = GET_PORT(this, direction, port_id);
 
-	spa_log_debug(this->log, NAME " %p: set format %d", this, this->have_format);
+	spa_log_debug(this->log, NAME " %p: set format", this);
 
 	if (format == NULL) {
 		if (port->have_format) {
 			port->have_format = false;
-			if (--this->n_formats == 0)
-				this->have_format = false;
 			clear_buffers(this, port);
 		}
 	} else {
@@ -595,22 +611,22 @@ static int port_set_format(struct spa_node *node,
 		if (spa_format_audio_raw_parse(format, &info.info.raw) < 0)
 			return -EINVAL;
 
-		if ((this->have_format || this->force_rate) &&
-		    info.info.raw.rate != this->format.info.raw.rate)
-			return -EINVAL;
-
-		if (direction == SPA_DIRECTION_INPUT) {
-			if (info.info.raw.channels != this->port_count)
+		if (direction == SPA_DIRECTION_OUTPUT) {
+			if (info.info.raw.rate != port->format.info.raw.rate)
 				return -EINVAL;
-		} else {
 			if (info.info.raw.format != SPA_AUDIO_FORMAT_F32P)
 				return -EINVAL;
 			if (info.info.raw.channels != 1)
 				return -EINVAL;
 		}
+		else {
+			if (info.info.raw.channels != this->port_count)
+				return -EINVAL;
+		}
 
 		port->format = info;
 		port->stride = calc_width(&info);
+
 		if (SPA_AUDIO_FORMAT_IS_PLANAR(info.info.raw.format)) {
 			port->blocks = info.info.raw.channels;
 		} else {
@@ -619,16 +635,10 @@ static int port_set_format(struct spa_node *node,
 		}
 		spa_log_debug(this->log, NAME " %p: %d %d %d", this, port_id, port->stride, port->blocks);
 
-		this->have_format = true;
-		this->format = info;
+		if (direction == SPA_DIRECTION_INPUT)
+			setup_convert(this);
 
-		if (!port->have_format) {
-			this->n_formats++;
-			port->have_format = true;
-			spa_log_debug(this->log, NAME " %p: set format on port %d", this, port_id);
-		}
-
-		setup_convert(this);
+		port->have_format = true;
 	}
 
 	return 0;
@@ -848,7 +858,7 @@ static int impl_node_process(struct spa_node *node)
 	dst_datas = alloca(sizeof(void*) * MAX_PORTS);
 
 	n_dst_datas = 0;
-	for (i = 0; i < this->last_port; i++) {
+	for (i = 0; i < this->port_count; i++) {
 		struct port *outport = GET_OUT_PORT(this, i);
 		struct spa_io_buffers *outio;
 
@@ -962,10 +972,7 @@ impl_init(const struct spa_handle_factory *factory,
 {
 	struct impl *this;
 	struct port *port;
-	uint32_t i;
-	const char *str;
-	int rate;
-
+	int i;
 
 	spa_return_val_if_fail(factory != NULL, -EINVAL);
 	spa_return_val_if_fail(handle != NULL, -EINVAL);
@@ -980,17 +987,9 @@ impl_init(const struct spa_handle_factory *factory,
 			this->log = support[i].data;
 	}
 
-	if ((str = spa_dict_lookup(info, "node.format.rate")))
-		if ((rate = atoi(str)) != 0) {
-			this->format.info.raw.rate = rate;
-			this->force_rate = true;
-		}
-
 	this->node = impl_node;
-	this->have_format = false;
 
 	port = GET_IN_PORT(this, 0);
-	port->valid = true;
 	port->id = 0;
 	port->info.flags = SPA_PORT_INFO_FLAG_CAN_USE_BUFFERS;
 
diff --git a/src/examples/media-session.c b/src/examples/media-session.c
index e93f207f7..8ad86c5c0 100644
--- a/src/examples/media-session.c
+++ b/src/examples/media-session.c
@@ -739,7 +739,7 @@ static int find_session(void *data, struct session *sess)
 	return 0;
 }
 
-static int link_nodes(struct node *peer, enum pw_direction direction, struct node *node)
+static int link_nodes(struct node *peer, enum pw_direction direction, struct node *node, int max)
 {
 	struct impl *impl = peer->obj.impl;
 	struct port *p;
@@ -752,6 +752,9 @@ static int link_nodes(struct node *peer, enum pw_direction direction, struct nod
 		if (p->direction == direction)
 			continue;
 
+		if (max-- == 0)
+			return 0;
+
 		props = pw_properties_new(NULL, NULL);
 		if (p->direction == PW_DIRECTION_OUTPUT) {
 			pw_properties_setf(props, PW_LINK_OUTPUT_NODE_ID, "%d", node->obj.id);
@@ -793,7 +796,10 @@ static int rescan_node(struct impl *impl, struct node *node)
 	struct pw_node_info *info;
 	struct node *peer;
 	enum pw_direction direction;
+	struct spa_pod_builder b = { 0, };
 	struct spa_audio_info_raw audio_info;
+	struct spa_pod *param;
+	char buf[1024];
 
 	if (node->type == NODE_TYPE_DSP || node->type == NODE_TYPE_DEVICE)
 		return 0;
@@ -906,12 +912,26 @@ static int rescan_node(struct impl *impl, struct node *node)
 	node->session = session;
 	spa_list_append(&session->node_list, &node->session_link);
 
-	audio_info = node->format;
-	audio_info.format = SPA_AUDIO_FORMAT_F32P;
-	audio_info.rate = session->node->format.rate;
-	audio_info.channels = SPA_MIN(session->node->format.channels, audio_info.channels);
+	if (!exclusive) {
+		audio_info = node->format;
+		audio_info.format = SPA_AUDIO_FORMAT_F32P;
+		audio_info.rate = session->node->format.rate;
+		audio_info.channels = SPA_MIN(session->node->format.channels, audio_info.channels);
 
-	link_nodes(peer, direction, node);
+		spa_pod_builder_init(&b, buf, sizeof(buf));
+		param = spa_pod_builder_object(&b,
+			SPA_TYPE_OBJECT_ParamProfile, SPA_PARAM_Profile,
+			SPA_PARAM_PROFILE_direction, &SPA_POD_Id(pw_direction_reverse(direction)),
+			SPA_PARAM_PROFILE_format,    spa_format_audio_raw_build(&b,
+							SPA_PARAM_Format, &audio_info),
+			0);
+
+		pw_node_proxy_set_param((struct pw_node_proxy*)node->obj.proxy,
+				SPA_PARAM_Profile, 0, param);
+	} else {
+		audio_info.channels = 1;
+	}
+	link_nodes(peer, direction, node, audio_info.channels);
 
         return 1;
 }
@@ -944,20 +964,18 @@ static void rescan_session(struct impl *impl, struct session *sess)
 	if (sess->need_dsp && sess->dsp == NULL && sess->dsp_proxy == NULL) {
 		struct pw_properties *props;
 		struct node *node = sess->node;
-		int i;
-		uint64_t mask = 0;
+		struct spa_audio_info_raw info;
+		uint8_t buf[1024];
+		struct spa_pod_builder b = { 0, };
+		struct spa_pod *param;
 
 		if (node->info->props == NULL)
 			return;
 
-		for (i = 0; i < node->format.channels; i++)
-			mask |= 1UL << node->format.position[i];
+		info = node->format;
 
 		props = pw_properties_new_dict(node->info->props);
 		pw_properties_setf(props, "audio-dsp.direction", "%d", sess->direction);
-		pw_properties_setf(props, "audio-dsp.channels", "%d", node->format.channels);
-		pw_properties_setf(props, "audio-dsp.channelmask", "%"PRIu64, mask);
-		pw_properties_setf(props, "audio-dsp.rate", "%d", node->format.rate);
 		pw_properties_setf(props, "audio-dsp.maxbuffer", "%ld", MAX_QUANTUM_SIZE * sizeof(float));
 
 		pw_log_debug(NAME" %p: making audio dsp for session %d", impl, sess->id);
@@ -971,6 +989,18 @@ static void rescan_session(struct impl *impl, struct session *sess)
 		pw_properties_free(props);
 
 		pw_proxy_add_proxy_listener(sess->dsp_proxy, &sess->listener, &dsp_node_events, sess);
+
+		spa_pod_builder_init(&b, buf, sizeof(buf));
+		param = spa_format_audio_raw_build(&b, SPA_PARAM_Format, &info);
+		param = spa_pod_builder_object(&b,
+			SPA_TYPE_OBJECT_ParamProfile, SPA_PARAM_Profile,
+			SPA_PARAM_PROFILE_direction, &SPA_POD_Id(pw_direction_reverse(sess->direction)),
+			SPA_PARAM_PROFILE_format,    param,
+			0);
+
+		pw_node_proxy_set_param((struct pw_node_proxy*)sess->dsp_proxy,
+				SPA_PARAM_Profile, 0, param);
+		schedule_rescan(impl);
 	}
 	else {
 		sess->starting = false;
diff --git a/src/modules/module-audio-dsp.c b/src/modules/module-audio-dsp.c
index 043f4350c..d04a0a242 100644
--- a/src/modules/module-audio-dsp.c
+++ b/src/modules/module-audio-dsp.c
@@ -96,8 +96,7 @@ static void *create_object(void *_data,
 	struct factory_data *d = _data;
 	struct pw_client *client;
 	struct pw_node *dsp;
-	int res, channels, rate, maxbuffer;
-	uint64_t channelmask;
+	int res, maxbuffer;
 	const char *str;
 	enum pw_direction direction;
 	struct node_data *nd;
@@ -113,21 +112,6 @@ static void *create_object(void *_data,
 
 	direction = pw_properties_parse_int(str);
 
-	if ((str = pw_properties_get(properties, "audio-dsp.channels")) == NULL)
-		goto no_props;
-
-	channels = pw_properties_parse_int(str);
-
-	if ((str = pw_properties_get(properties, "audio-dsp.channelmask")) == NULL)
-		goto no_props;
-
-	channelmask = pw_properties_parse_uint64(str);
-
-	if ((str = pw_properties_get(properties, "audio-dsp.rate")) == NULL)
-		goto no_props;
-
-	rate = pw_properties_parse_int(str);
-
 	if ((str = pw_properties_get(properties, "audio-dsp.maxbuffer")) == NULL)
 		goto no_props;
 
@@ -136,7 +120,7 @@ static void *create_object(void *_data,
 	dsp = pw_audio_dsp_new(pw_module_get_core(d->module),
 			properties,
 			direction,
-			channels, channelmask, rate, maxbuffer,
+			maxbuffer,
 			sizeof(struct node_data));
 
 	if (dsp == NULL)
diff --git a/src/modules/module-audio-dsp/audio-dsp.c b/src/modules/module-audio-dsp/audio-dsp.c
index b1ab43e24..b539695c5 100644
--- a/src/modules/module-audio-dsp/audio-dsp.c
+++ b/src/modules/module-audio-dsp/audio-dsp.c
@@ -43,6 +43,7 @@
 #define NAME "audio-dsp"
 
 #define PORT_BUFFERS	1
+#define MAX_BUFFER_SIZE	2048
 
 extern const struct spa_handle_factory spa_floatmix_factory;
 
@@ -55,6 +56,8 @@ struct buffer {
 struct node;
 
 struct port {
+	struct spa_list link;
+
 	struct pw_port *port;
 	struct node *node;
 
@@ -65,19 +68,23 @@ struct port {
 	struct spa_handle *spa_handle;
 	struct spa_node *spa_node;
 
-	float empty[4096];
+	float empty[MAX_BUFFER_SIZE];
 };
 
 struct node {
 	struct pw_core *core;
+
 	struct pw_node *node;
+	struct spa_hook node_listener;
 
 	void *user_data;
+	enum pw_direction direction;
+	struct pw_properties *props;
 
-	int channels;
-	uint64_t channelmask;
-	int sample_rate;
+	struct spa_audio_info format;
 	int max_buffer_size;
+
+	struct spa_list ports;
 };
 
 /** \endcond */
@@ -101,6 +108,7 @@ static void init_buffer(struct port *port, uint32_t id)
 	b->datas[0].chunk->size = 0;
 	b->datas[0].chunk->stride = 0;
 	port->bufs[id] = &b->buf;
+	memset(port->empty, 0, sizeof(port->empty));
 }
 
 static void init_port(struct port *p, enum spa_direction direction)
@@ -146,46 +154,95 @@ static const struct pw_port_implementation port_implementation = {
 	.use_buffers = port_use_buffers,
 };
 
-static int make_channel_name(struct node *n, char *channel_name, int i, uint64_t channelmask)
+static void node_destroy(void *data)
 {
-	int j;
-
-	sprintf(channel_name, "%d", i + 1);
-	for (j = 0; j < 64; j++) {
-		if (channelmask & (1LL << j)) {
-			if (i-- == 0) {
-				sprintf(channel_name, "%s",
-						rindex(spa_type_audio_channel[j].name, ':')+1);
-				return 1;
-			}
-		}
-	}
-	return 0;
+	struct node *n = data;
+	pw_properties_free(n->props);
 }
 
+static void node_port_init(void *data, struct pw_port *port)
+{
+	struct node *n = data;
+	struct port *p;
+	const struct pw_properties *old;
+	enum pw_direction direction;
+	struct pw_properties *new;
+	const char *str;
+	void *iface;
+	const struct spa_support *support;
+	uint32_t n_support;
+
+	direction = pw_port_get_direction(port);
+	if (direction == n->direction)
+		return;
+
+	old = pw_port_get_properties(port);
+
+	new = pw_properties_new(
+			"port.dsp", "32 bit float mono audio",
+			"port.physical", "1",
+			"port.terminal", "1",
+			NULL);
+
+	if ((str = pw_properties_get(old, "port.channel")) != NULL)
+		pw_properties_setf(new, "port.name", "%s_%s",
+			direction == PW_DIRECTION_INPUT ? "playback" : "capture",
+			str);
+
+	pw_properties_setf(new, "port.alias1", "%s_pcm:%s:%s%s",
+			pw_properties_get(n->props, "device.api"),
+			pw_properties_get(n->props, "device.name"),
+			direction == PW_DIRECTION_INPUT ? "in" : "out",
+			str ? str : "UNK");
+
+	pw_port_update_properties(port, &new->dict);
+	pw_properties_free(new);
+
+	p = calloc(1, sizeof(struct port) +
+			spa_handle_factory_get_size(&spa_floatmix_factory, NULL));
+	p->node = n;
+	p->port = port;
+	init_port(p, direction);
+	p->spa_handle = SPA_MEMBER(p, sizeof(struct port), struct spa_handle);
+
+	support = pw_core_get_support(n->core, &n_support);
+	spa_handle_factory_init(&spa_floatmix_factory,
+			p->spa_handle, NULL,
+			support, n_support);
+
+	spa_handle_get_interface(p->spa_handle, SPA_TYPE_INTERFACE_Node, &iface);
+	p->spa_node = iface;
+
+	if (direction == PW_DIRECTION_INPUT) {
+		pw_log_debug("mix node %p", p->spa_node);
+		pw_port_set_mix(port, p->spa_node, PW_PORT_MIX_FLAG_MULTI);
+		port->implementation = &port_implementation;
+		port->implementation_data = p;
+	}
+	spa_list_append(&n->ports, &p->link);
+}
+
+static const struct pw_node_events node_events = {
+	PW_VERSION_NODE_EVENTS,
+	.destroy = node_destroy,
+	.port_init = node_port_init,
+};
+
 struct pw_node *pw_audio_dsp_new(struct pw_core *core,
 		const struct pw_properties *props,
 		enum pw_direction direction,
-		uint32_t channels,
-		uint64_t channelmask,
-		uint32_t sample_rate,
 		uint32_t max_buffer_size,
 		size_t user_data_size)
 {
 	struct pw_node *node;
-	struct pw_port *port;
 	struct node *n;
 	const char *api, *alias, *plugged, *str;
 	char node_name[128];
 	struct pw_properties *pr;
-	const struct spa_support *support;
-	uint32_t n_support;
-	void *iface;
 	int i;
 
 	if ((api = pw_properties_get(props, "device.api")) == NULL)
 		goto error;
-
 	if ((alias = pw_properties_get(props, "device.name")) == NULL)
 		goto error;
 
@@ -201,6 +258,7 @@ struct pw_node *pw_audio_dsp_new(struct pw_core *core,
 				"Audio/DSP/Playback" :
 				"Audio/DSP/Capture",
 			"device.name", alias,
+			"device.api", api,
 			NULL);
 
 	if ((plugged = pw_properties_get(props, "node.plugged")) != NULL)
@@ -208,10 +266,6 @@ struct pw_node *pw_audio_dsp_new(struct pw_core *core,
 	if ((str = pw_properties_get(props, "node.id")) != NULL)
 		pw_properties_set(pr, "node.session", str);
 
-	pw_properties_setf(pr, "node.format.rate", "%d", sample_rate);
-	pw_properties_setf(pr, "node.format.channels", "%d", channels);
-	pw_properties_setf(pr, "node.format.channelmask", "%"PRIu64, channelmask);
-
 	node = pw_spa_node_load(core, NULL, NULL,
 			"audioconvert/libspa-audioconvert",
 			direction == PW_DIRECTION_OUTPUT ?
@@ -227,83 +281,19 @@ struct pw_node *pw_audio_dsp_new(struct pw_core *core,
 	n = pw_spa_node_get_user_data(node);
 	n->core = core;
 	n->node = node;
+	n->direction = direction;
+	n->props = pw_properties_copy(props);
+	spa_list_init(&n->ports);
 
-	n->channels = channels;
-	n->channelmask = channelmask;
-	n->sample_rate = sample_rate;
 	n->max_buffer_size = max_buffer_size;
 
 	if (user_data_size > 0)
 		n->user_data = SPA_MEMBER(n, sizeof(struct node), void);
 
-	pw_node_update_ports(node);
+	pw_node_add_listener(node, &n->node_listener, &node_events, n);
 
-	direction = pw_direction_reverse(direction);
-
-	support = pw_core_get_support(core, &n_support);
-
-	for (i = 0; i < n->channels; i++) {
-		struct port *p;
-		struct pw_properties *props;
-		char channel_name[16];
-
-		make_channel_name(n, channel_name, i, channelmask);
-
-		props = pw_properties_new(
-				"port.dsp", "32 bit float mono audio",
-				"port.physical", "1",
-				"port.terminal", "1",
-				NULL);
-		pw_properties_setf(props, "port.name", "%s_%s",
-				direction == PW_DIRECTION_INPUT ? "playback" : "capture",
-				channel_name);
-		pw_properties_setf(props, "port.alias1", "%s_pcm:%s:%s%s",
-				api,
-				alias,
-				direction == PW_DIRECTION_INPUT ? "in" : "out",
-				channel_name);
-		pw_properties_setf(props, "port.channel", "%s", channel_name);
-
-		port = pw_port_new(direction,
-				   i,
-				   props,
-				   sizeof(struct port) +
-				   spa_handle_factory_get_size(&spa_floatmix_factory, NULL));
-		if (port == NULL)
-			goto error_free_node;
-
-
-		p = pw_port_get_user_data(port);
-		port->owner_data = p;
-		p->node = n;
-		p->port = port;
-		init_port(p, direction);
-		p->spa_handle = SPA_MEMBER(p, sizeof(struct port), struct spa_handle);
-
-		spa_handle_factory_init(&spa_floatmix_factory,
-				p->spa_handle, NULL,
-				support, n_support);
-
-		spa_handle_get_interface(p->spa_handle, SPA_TYPE_INTERFACE_Node, &iface);
-
-		p->spa_node = iface;
-
-		if (direction == PW_DIRECTION_INPUT) {
-			pw_log_debug("mix node %p", p->spa_node);
-
-			pw_port_set_mix(port, p->spa_node, PW_PORT_MIX_FLAG_MULTI);
-			port->implementation = &port_implementation;
-			port->implementation_data = p;
-		}
-		if (pw_port_add(port, node) < 0)
-			goto error_free_port;
-	}
 	return node;
 
-     error_free_port:
-	pw_port_destroy(port);
-     error_free_node:
-	pw_node_destroy(node);
      error:
 	return NULL;
 }
diff --git a/src/modules/module-audio-dsp/audio-dsp.h b/src/modules/module-audio-dsp/audio-dsp.h
index 75034260c..4253bf2d4 100644
--- a/src/modules/module-audio-dsp/audio-dsp.h
+++ b/src/modules/module-audio-dsp/audio-dsp.h
@@ -31,9 +31,6 @@ struct pw_node *
 pw_audio_dsp_new(struct pw_core *core,
 		 const struct pw_properties *properties,
 		 enum pw_direction direction,
-		 uint32_t channels,
-		 uint64_t channelmask,
-		 uint32_t sample_rate,
 		 uint32_t max_buffer_size,
 		 size_t user_data_size);
 
diff --git a/src/modules/module-client-node/client-stream.c b/src/modules/module-client-node/client-stream.c
index 3533230ce..3aa47d674 100644
--- a/src/modules/module-client-node/client-stream.c
+++ b/src/modules/module-client-node/client-stream.c
@@ -126,7 +126,30 @@ static int impl_node_enum_params(struct spa_node *node,
 static int impl_node_set_param(struct spa_node *node, uint32_t id, uint32_t flags,
 			       const struct spa_pod *param)
 {
-	return 0;
+	int res = 0;
+	struct node *this;
+	struct impl *impl;
+
+	this = SPA_CONTAINER_OF(node, struct node, node);
+	impl = this->impl;
+
+	switch (id) {
+	case SPA_PARAM_Profile:
+		if (impl->started)
+			return -EIO;
+		if (impl->adapter != impl->cnode) {
+			spa_node_set_param(impl->adapter, id, flags, param);
+
+			if (this->callbacks && this->callbacks->event)
+				this->callbacks->event(this->callbacks_data,
+					&SPA_NODE_EVENT_INIT(SPA_NODE_EVENT_PortsChanged));
+		}
+		break;
+	default:
+		res = -ENOTSUP;
+		break;
+	}
+	return res;
 }
 
 static int impl_node_send_command(struct spa_node *node, const struct spa_command *command)
@@ -958,6 +981,12 @@ static void client_node_initialized(void *data)
 					impl->client_port_mix.io,
 					sizeof(impl->client_port_mix.io))) < 0)
 			return;
+		if ((res = spa_node_port_set_io(impl->adapter_mix,
+					impl->direction, 0,
+					SPA_IO_Range,
+					&impl->range,
+					sizeof(&impl->range))) < 0)
+			return;
 	}
 
 	switch (media_type) {