diff --git a/spa/plugins/alsa/alsa-pcm-sink.c b/spa/plugins/alsa/alsa-pcm-sink.c
index c52241cc7..d24fdf83f 100644
--- a/spa/plugins/alsa/alsa-pcm-sink.c
+++ b/spa/plugins/alsa/alsa-pcm-sink.c
@@ -520,11 +520,11 @@ static int port_set_format(void *object,
 	this->port_info.rate = SPA_FRACTION(1, this->rate);
 	this->port_info.change_mask |= SPA_PORT_CHANGE_MASK_PARAMS;
 	if (this->have_format) {
-		this->port_params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_READWRITE);
-		this->port_params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, SPA_PARAM_INFO_READ);
+		this->port_params[IDX_Format] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_READWRITE);
+		this->port_params[IDX_Buffers] = SPA_PARAM_INFO(SPA_PARAM_Buffers, SPA_PARAM_INFO_READ);
 	} else {
-		this->port_params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
-		this->port_params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
+		this->port_params[IDX_Format] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
+		this->port_params[IDX_Buffers] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
 	}
 	emit_port_info(this, false);
 
@@ -762,11 +762,11 @@ impl_init(const struct spa_handle_factory *factory,
 	this->info = SPA_NODE_INFO_INIT();
 	this->info.max_input_ports = 1;
 	this->info.flags = SPA_NODE_FLAG_RT;
-	this->params[0] = SPA_PARAM_INFO(SPA_PARAM_PropInfo, SPA_PARAM_INFO_READ);
-	this->params[1] = SPA_PARAM_INFO(SPA_PARAM_Props, SPA_PARAM_INFO_READWRITE);
-	this->params[2] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
+	this->params[IDX_PropInfo] = SPA_PARAM_INFO(SPA_PARAM_PropInfo, SPA_PARAM_INFO_READ);
+	this->params[IDX_Props] = SPA_PARAM_INFO(SPA_PARAM_Props, SPA_PARAM_INFO_READWRITE);
+	this->params[IDX_NODE_IO] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
 	this->info.params = this->params;
-	this->info.n_params = 3;
+	this->info.n_params = N_NODE_PARAMS;
 
 	reset_props(&this->props);
 
@@ -776,13 +776,13 @@ impl_init(const struct spa_handle_factory *factory,
 	this->port_info.flags = SPA_PORT_FLAG_LIVE |
 			   SPA_PORT_FLAG_PHYSICAL |
 			   SPA_PORT_FLAG_TERMINAL;
-	this->port_params[0] = SPA_PARAM_INFO(SPA_PARAM_EnumFormat, SPA_PARAM_INFO_READ);
-	this->port_params[1] = SPA_PARAM_INFO(SPA_PARAM_Meta, SPA_PARAM_INFO_READ);
-	this->port_params[2] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
-	this->port_params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
-	this->port_params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
+	this->port_params[IDX_EnumFormat] = SPA_PARAM_INFO(SPA_PARAM_EnumFormat, SPA_PARAM_INFO_READ);
+	this->port_params[IDX_Meta] = SPA_PARAM_INFO(SPA_PARAM_Meta, SPA_PARAM_INFO_READ);
+	this->port_params[IDX_IO] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
+	this->port_params[IDX_Format] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
+	this->port_params[IDX_Buffers] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
 	this->port_info.params = this->port_params;
-	this->port_info.n_params = 5;
+	this->port_info.n_params = N_PORT_PARAMS;
 
 	spa_list_init(&this->ready);
 
diff --git a/spa/plugins/alsa/alsa-pcm-source.c b/spa/plugins/alsa/alsa-pcm-source.c
index 273139e8e..128ebae34 100644
--- a/spa/plugins/alsa/alsa-pcm-source.c
+++ b/spa/plugins/alsa/alsa-pcm-source.c
@@ -519,11 +519,11 @@ static int port_set_format(void *object,
 	this->port_info.rate = SPA_FRACTION(1, this->rate);
 	this->port_info.change_mask |= SPA_PORT_CHANGE_MASK_PARAMS;
 	if (this->have_format) {
-		this->port_params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_READWRITE);
-		this->port_params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, SPA_PARAM_INFO_READ);
+		this->port_params[IDX_Format] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_READWRITE);
+		this->port_params[IDX_Buffers] = SPA_PARAM_INFO(SPA_PARAM_Buffers, SPA_PARAM_INFO_READ);
 	} else {
-		this->port_params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
-		this->port_params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
+		this->port_params[IDX_Format] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
+		this->port_params[IDX_Buffers] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
 	}
 	emit_port_info(this, false);
 
@@ -782,11 +782,11 @@ impl_init(const struct spa_handle_factory *factory,
 			SPA_NODE_CHANGE_MASK_PARAMS;
 	this->info.max_output_ports = 1;
 	this->info.flags = SPA_NODE_FLAG_RT;
-	this->params[0] = SPA_PARAM_INFO(SPA_PARAM_PropInfo, SPA_PARAM_INFO_READ);
-	this->params[1] = SPA_PARAM_INFO(SPA_PARAM_Props, SPA_PARAM_INFO_READWRITE);
-	this->params[2] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
+	this->params[IDX_PropInfo] = SPA_PARAM_INFO(SPA_PARAM_PropInfo, SPA_PARAM_INFO_READ);
+	this->params[IDX_Props] = SPA_PARAM_INFO(SPA_PARAM_Props, SPA_PARAM_INFO_READWRITE);
+	this->params[IDX_NODE_IO] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
 	this->info.params = this->params;
-	this->info.n_params = 3;
+	this->info.n_params = N_NODE_PARAMS;
 	reset_props(&this->props);
 
 	this->port_info_all = SPA_PORT_CHANGE_MASK_FLAGS |
@@ -795,13 +795,13 @@ impl_init(const struct spa_handle_factory *factory,
 	this->port_info.flags = SPA_PORT_FLAG_LIVE |
 			   SPA_PORT_FLAG_PHYSICAL |
 			   SPA_PORT_FLAG_TERMINAL;
-	this->port_params[0] = SPA_PARAM_INFO(SPA_PARAM_EnumFormat, SPA_PARAM_INFO_READ);
-	this->port_params[1] = SPA_PARAM_INFO(SPA_PARAM_Meta, SPA_PARAM_INFO_READ);
-	this->port_params[2] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
-	this->port_params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
-	this->port_params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
+	this->port_params[IDX_EnumFormat] = SPA_PARAM_INFO(SPA_PARAM_EnumFormat, SPA_PARAM_INFO_READ);
+	this->port_params[IDX_Meta] = SPA_PARAM_INFO(SPA_PARAM_Meta, SPA_PARAM_INFO_READ);
+	this->port_params[IDX_IO] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
+	this->port_params[IDX_Format] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
+	this->port_params[IDX_Buffers] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
 	this->port_info.params = this->port_params;
-	this->port_info.n_params = 5;
+	this->port_info.n_params = N_PORT_PARAMS;
 
 	spa_list_init(&this->free);
 	spa_list_init(&this->ready);
diff --git a/spa/plugins/alsa/alsa-pcm.h b/spa/plugins/alsa/alsa-pcm.h
index 6803b4eb7..48d6fdf87 100644
--- a/spa/plugins/alsa/alsa-pcm.h
+++ b/spa/plugins/alsa/alsa-pcm.h
@@ -101,7 +101,11 @@ struct state {
 
 	uint64_t info_all;
 	struct spa_node_info info;
-	struct spa_param_info params[8];
+#define IDX_PropInfo	0
+#define IDX_Props	1
+#define IDX_NODE_IO	2
+#define N_NODE_PARAMS	3
+	struct spa_param_info params[N_NODE_PARAMS];
 	struct props props;
 
 	bool opened;
@@ -134,7 +138,13 @@ struct state {
 
 	uint64_t port_info_all;
 	struct spa_port_info port_info;
-	struct spa_param_info port_params[8];
+#define IDX_EnumFormat	0
+#define IDX_Meta	1
+#define IDX_IO		2
+#define IDX_Format	3
+#define IDX_Buffers	4
+#define N_PORT_PARAMS	5
+	struct spa_param_info port_params[N_PORT_PARAMS];
 	struct spa_io_buffers *io;
 	struct spa_io_clock *clock;
 	struct spa_io_position *position;
diff --git a/spa/plugins/alsa/alsa-seq-bridge.c b/spa/plugins/alsa/alsa-seq-bridge.c
index 94f0e0edb..85556449c 100644
--- a/spa/plugins/alsa/alsa-seq-bridge.c
+++ b/spa/plugins/alsa/alsa-seq-bridge.c
@@ -404,14 +404,14 @@ static void init_port(struct seq_state *state, struct seq_port *port, const snd_
 	port->info.flags = SPA_PORT_FLAG_LIVE;
 	if (caps & (SND_SEQ_PORT_TYPE_HARDWARE|SND_SEQ_PORT_TYPE_PORT|SND_SEQ_PORT_TYPE_SPECIFIC))
 		port->info.flags |= SPA_PORT_FLAG_PHYSICAL | SPA_PORT_FLAG_TERMINAL;
-	port->params[0] = SPA_PARAM_INFO(SPA_PARAM_EnumFormat, SPA_PARAM_INFO_READ);
-	port->params[1] = SPA_PARAM_INFO(SPA_PARAM_Meta, SPA_PARAM_INFO_READ);
-	port->params[2] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
-	port->params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
-	port->params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
+	port->params[IDX_EnumFormat] = SPA_PARAM_INFO(SPA_PARAM_EnumFormat, SPA_PARAM_INFO_READ);
+	port->params[IDX_Meta] = SPA_PARAM_INFO(SPA_PARAM_Meta, SPA_PARAM_INFO_READ);
+	port->params[IDX_IO] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
+	port->params[IDX_Format] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
+	port->params[IDX_Buffers] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
 
 	port->info.params = port->params;
-	port->info.n_params = 5;
+	port->info.n_params = N_PORT_PARAMS;
 
 	spa_list_init(&port->free);
 	spa_list_init(&port->ready);
@@ -627,11 +627,11 @@ static int port_set_format(void *object, struct seq_port *port,
 	port->info.rate = SPA_FRACTION(1, 1);
 	port->info.change_mask |= SPA_PORT_CHANGE_MASK_PARAMS;
 	if (port->have_format) {
-		port->params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_READWRITE);
-		port->params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, SPA_PARAM_INFO_READ);
+		port->params[IDX_Format] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_READWRITE);
+		port->params[IDX_Buffers] = SPA_PARAM_INFO(SPA_PARAM_Buffers, SPA_PARAM_INFO_READ);
 	} else {
-		port->params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
-		port->params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
+		port->params[IDX_Format] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
+		port->params[IDX_Buffers] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
 	}
 	emit_port_info(this, port, false);
 
@@ -870,11 +870,11 @@ impl_init(const struct spa_handle_factory *factory,
 	this->info.max_input_ports = MAX_PORTS;
 	this->info.max_output_ports = MAX_PORTS;
 	this->info.flags = SPA_NODE_FLAG_RT;
-	this->params[0] = SPA_PARAM_INFO(SPA_PARAM_PropInfo, SPA_PARAM_INFO_READ);
-	this->params[1] = SPA_PARAM_INFO(SPA_PARAM_Props, SPA_PARAM_INFO_READWRITE);
-	this->params[2] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
+	this->params[IDX_PropInfo] = SPA_PARAM_INFO(SPA_PARAM_PropInfo, SPA_PARAM_INFO_READ);
+	this->params[IDX_Props] = SPA_PARAM_INFO(SPA_PARAM_Props, SPA_PARAM_INFO_READWRITE);
+	this->params[IDX_NODE_IO] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
 	this->info.params = this->params;
-	this->info.n_params = 3;
+	this->info.n_params = N_NODE_PARAMS;
 	reset_props(&this->props);
 
 	for (i = 0; info && i < info->n_items; i++) {
diff --git a/spa/plugins/alsa/alsa-seq.h b/spa/plugins/alsa/alsa-seq.h
index fc4019003..d55119b07 100644
--- a/spa/plugins/alsa/alsa-seq.h
+++ b/spa/plugins/alsa/alsa-seq.h
@@ -71,7 +71,13 @@ struct seq_port {
 
 	uint64_t info_all;
 	struct spa_port_info info;
-	struct spa_param_info params[8];
+#define IDX_EnumFormat	0
+#define IDX_Meta	1
+#define IDX_IO		2
+#define IDX_Format	3
+#define IDX_Buffers	4
+#define N_PORT_PARAMS	5
+	struct spa_param_info params[N_PORT_PARAMS];
 
 	struct spa_io_buffers *io;
 
@@ -128,7 +134,11 @@ struct seq_state {
 
 	uint64_t info_all;
 	struct spa_node_info info;
-	struct spa_param_info params[8];
+#define IDX_PropInfo	0
+#define IDX_Props	1
+#define IDX_NODE_IO	2
+#define N_NODE_PARAMS	3
+	struct spa_param_info params[N_NODE_PARAMS];
 	struct props props;
 
 	struct spa_io_clock *clock;