diff --git a/src/modules/module-protocol-pulse/collect.c b/src/modules/module-protocol-pulse/collect.c
index 2ae92b5b4..78a00fb42 100644
--- a/src/modules/module-protocol-pulse/collect.c
+++ b/src/modules/module-protocol-pulse/collect.c
@@ -232,7 +232,7 @@ uint32_t find_profile_id(struct pw_manager_object *card, const char *name)
 }
 
 void collect_device_info(struct pw_manager_object *device, struct pw_manager_object *card,
-			 struct device_info *dev_info, bool monitor)
+			 struct device_info *dev_info, bool monitor, struct defs *defs)
 {
 	struct pw_manager_param *p;
 
@@ -266,12 +266,14 @@ void collect_device_info(struct pw_manager_object *device, struct pw_manager_obj
 		{
 			struct spa_pod *copy = spa_pod_copy(p->param);
 			spa_pod_fixate(copy);
-			format_parse_param(copy, &dev_info->ss, &dev_info->map);
+			format_parse_param(copy, &dev_info->ss, &dev_info->map,
+					&defs->sample_spec, &defs->channel_map);
 			free(copy);
 			break;
 		}
 		case SPA_PARAM_Format:
-			format_parse_param(p->param, &dev_info->ss, &dev_info->map);
+			format_parse_param(p->param, &dev_info->ss, &dev_info->map,
+					NULL, NULL);
 			break;
 
 		case SPA_PARAM_Props:
diff --git a/src/modules/module-protocol-pulse/collect.h b/src/modules/module-protocol-pulse/collect.h
index 56bbc4c4a..ad15846ea 100644
--- a/src/modules/module-protocol-pulse/collect.h
+++ b/src/modules/module-protocol-pulse/collect.h
@@ -32,6 +32,7 @@
 #include <spa/param/bluetooth/audio.h>
 #include <pipewire/pipewire.h>
 
+#include "internal.h"
 #include "format.h"
 #include "volume.h"
 
@@ -79,7 +80,7 @@ struct device_info {
 	}
 
 void collect_device_info(struct pw_manager_object *device, struct pw_manager_object *card,
-			 struct device_info *dev_info, bool monitor);
+			 struct device_info *dev_info, bool monitor, struct defs *defs);
 
 /* ========================================================================== */
 
diff --git a/src/modules/module-protocol-pulse/format.c b/src/modules/module-protocol-pulse/format.c
index 04bd6f2bd..7c111a695 100644
--- a/src/modules/module-protocol-pulse/format.c
+++ b/src/modules/module-protocol-pulse/format.c
@@ -424,7 +424,27 @@ static enum encoding format_encoding_from_id(uint32_t id)
 	return ENCODING_ANY;
 }
 
-int format_parse_param(const struct spa_pod *param, struct sample_spec *ss, struct channel_map *map)
+static inline int
+audio_raw_parse_opt(const struct spa_pod *format, struct spa_audio_info_raw *info)
+{
+	struct spa_pod *position = NULL;
+	int res;
+	info->flags = 0;
+	res = spa_pod_parse_object(format,
+			SPA_TYPE_OBJECT_Format, NULL,
+			SPA_FORMAT_AUDIO_format,        SPA_POD_OPT_Id(&info->format),
+			SPA_FORMAT_AUDIO_rate,          SPA_POD_OPT_Int(&info->rate),
+			SPA_FORMAT_AUDIO_channels,      SPA_POD_OPT_Int(&info->channels),
+			SPA_FORMAT_AUDIO_position,      SPA_POD_OPT_Pod(&position));
+	if (position == NULL ||
+	    !spa_pod_copy_array(position, SPA_TYPE_Id, info->position, SPA_AUDIO_MAX_CHANNELS))
+		SPA_FLAG_SET(info->flags, SPA_AUDIO_FLAG_UNPOSITIONED);
+
+	return res;
+}
+
+int format_parse_param(const struct spa_pod *param, struct sample_spec *ss, struct channel_map *map,
+		const struct sample_spec *def_ss, const struct channel_map *def_map)
 {
 	struct spa_audio_info info = { 0 };
 	uint32_t i;
@@ -437,8 +457,15 @@ int format_parse_param(const struct spa_pod *param, struct sample_spec *ss, stru
 
 	switch (info.media_subtype) {
 	case SPA_MEDIA_SUBTYPE_raw:
-		if (spa_format_audio_raw_parse(param, &info.info.raw) < 0)
-	                return -ENOTSUP;
+		if (def_ss != NULL) {
+			if (ss != NULL)
+				*ss = *def_ss;
+			if (audio_raw_parse_opt(param, &info.info.raw) < 0)
+		                return -ENOTSUP;
+		} else {
+			if (spa_format_audio_raw_parse(param, &info.info.raw) < 0)
+		                return -ENOTSUP;
+		}
 		break;
 	case SPA_MEDIA_SUBTYPE_iec958:
 	{
@@ -458,9 +485,12 @@ int format_parse_param(const struct spa_pod *param, struct sample_spec *ss, stru
 		return -ENOTSUP;
         }
 	if (ss) {
-	        ss->format = info.info.raw.format;
-	        ss->rate = info.info.raw.rate;
-	        ss->channels = info.info.raw.channels;
+		if (info.info.raw.format)
+		        ss->format = info.info.raw.format;
+		if (info.info.raw.rate)
+		        ss->rate = info.info.raw.rate;
+		if (info.info.raw.channels)
+		        ss->channels = info.info.raw.channels;
 	}
 	if (map) {
 		map->channels = info.info.raw.channels;
diff --git a/src/modules/module-protocol-pulse/format.h b/src/modules/module-protocol-pulse/format.h
index 2173bedc7..0acdce349 100644
--- a/src/modules/module-protocol-pulse/format.h
+++ b/src/modules/module-protocol-pulse/format.h
@@ -205,7 +205,8 @@ void channel_map_parse(const char *str, struct channel_map *map);
 bool channel_map_valid(const struct channel_map *map);
 
 int format_parse_param(const struct spa_pod *param, struct sample_spec *ss,
-		struct channel_map *map);
+		struct channel_map *map, const struct sample_spec *def_ss,
+		const struct channel_map *def_map);
 
 const struct spa_pod *format_build_param(struct spa_pod_builder *b, uint32_t id,
 		const struct sample_spec *spec, const struct channel_map *map);
diff --git a/src/modules/module-protocol-pulse/modules/module-zeroconf-publish.c b/src/modules/module-protocol-pulse/modules/module-zeroconf-publish.c
index c58fd0d46..f850bef77 100644
--- a/src/modules/module-protocol-pulse/modules/module-zeroconf-publish.c
+++ b/src/modules/module-protocol-pulse/modules/module-zeroconf-publish.c
@@ -233,6 +233,7 @@ static char* channel_map_snprint(char *s, size_t l, const struct channel_map *ma
 static void get_service_data(struct module_zeroconf_publish_data *d,
 		struct service *s, struct pw_manager_object *o)
 {
+	struct impl *impl = d->module->impl;
 	bool is_sink = pw_manager_object_is_sink(o);
 	bool is_source = pw_manager_object_is_source(o);
 	struct pw_node_info *info = o->info;
@@ -265,7 +266,7 @@ static void get_service_data(struct module_zeroconf_publish_data *d,
 	if (card)
 		collect_card_info(card, &card_info);
 
-	collect_device_info(o, card, &dev_info, false);
+	collect_device_info(o, card, &dev_info, false, &impl->defs);
 
 	if ((str = spa_dict_lookup(info->props, PW_KEY_DEVICE_API)) != NULL) {
 		if (pw_manager_object_is_sink(o))
diff --git a/src/modules/module-protocol-pulse/pulse-server.c b/src/modules/module-protocol-pulse/pulse-server.c
index e3039a580..e88b58847 100644
--- a/src/modules/module-protocol-pulse/pulse-server.c
+++ b/src/modules/module-protocol-pulse/pulse-server.c
@@ -981,7 +981,7 @@ static void stream_param_changed(void *data, uint32_t id, const struct spa_pod *
 	if (id != SPA_PARAM_Format || param == NULL)
 		return;
 
-	if ((res = format_parse_param(param, &stream->ss, &stream->map)) < 0) {
+	if ((res = format_parse_param(param, &stream->ss, &stream->map, NULL, NULL)) < 0) {
 		pw_stream_set_error(stream->stream, res, "format not supported");
 		return;
 	}
@@ -2669,7 +2669,7 @@ static int do_set_volume(struct client *client, uint32_t command, uint32_t tag,
 		struct selector sel = { .id = card_id, .type = pw_manager_object_is_card, };
 		card = select_object(manager, &sel);
 	}
-	collect_device_info(o, card, &dev_info, is_monitor);
+	collect_device_info(o, card, &dev_info, is_monitor, &impl->defs);
 
 	if (dev_info.have_volume &&
 	    volume_compare(&dev_info.volume_info.volume, &volume) == 0)
@@ -2735,7 +2735,7 @@ static int do_set_mute(struct client *client, uint32_t command, uint32_t tag, st
 		struct selector sel = { .id = card_id, .type = pw_manager_object_is_card, };
 		card = select_object(manager, &sel);
 	}
-	collect_device_info(o, card, &dev_info, is_monitor);
+	collect_device_info(o, card, &dev_info, is_monitor, &impl->defs);
 
 	if (dev_info.have_volume &&
 	    dev_info.volume_info.mute == mute)
@@ -3406,6 +3406,7 @@ static int fill_card_info(struct client *client, struct message *m,
 static int fill_sink_info(struct client *client, struct message *m,
 		struct pw_manager_object *o)
 {
+	struct impl *impl = client->impl;
 	struct pw_node_info *info = o->info;
 	struct pw_manager *manager = client->manager;
 	const char *name, *desc, *str;
@@ -3447,7 +3448,7 @@ static int fill_sink_info(struct client *client, struct message *m,
 	if (card)
 		collect_card_info(card, &card_info);
 
-	collect_device_info(o, card, &dev_info, false);
+	collect_device_info(o, card, &dev_info, false, &impl->defs);
 
 	if (!sample_spec_valid(&dev_info.ss) ||
 	    !channel_map_valid(&dev_info.map) ||
@@ -3576,6 +3577,7 @@ static int fill_sink_info(struct client *client, struct message *m,
 static int fill_source_info(struct client *client, struct message *m,
 		struct pw_manager_object *o)
 {
+	struct impl *impl = client->impl;
 	struct pw_node_info *info = o->info;
 	struct pw_manager *manager = client->manager;
 	bool is_monitor;
@@ -3622,7 +3624,7 @@ static int fill_source_info(struct client *client, struct message *m,
 	if (card)
 		collect_card_info(card, &card_info);
 
-	collect_device_info(o, card, &dev_info, is_monitor);
+	collect_device_info(o, card, &dev_info, is_monitor, &impl->defs);
 
 	if (!sample_spec_valid(&dev_info.ss) ||
 	    !channel_map_valid(&dev_info.map) ||
@@ -3740,6 +3742,7 @@ static const char *get_media_name(struct pw_node_info *info)
 static int fill_sink_input_info(struct client *client, struct message *m,
 		struct pw_manager_object *o)
 {
+	struct impl *impl = client->impl;
 	struct pw_node_info *info = o->info;
 	struct pw_manager *manager = client->manager;
 	struct pw_manager_object *peer;
@@ -3756,7 +3759,7 @@ static int fill_sink_input_info(struct client *client, struct message *m,
 	    (str = spa_dict_lookup(info->props, PW_KEY_CLIENT_ID)) != NULL)
 		client_id = (uint32_t)atoi(str);
 
-	collect_device_info(o, NULL, &dev_info, false);
+	collect_device_info(o, NULL, &dev_info, false, &impl->defs);
 
 	if (!sample_spec_valid(&dev_info.ss) ||
 	    !channel_map_valid(&dev_info.map) ||
@@ -3810,6 +3813,7 @@ static int fill_sink_input_info(struct client *client, struct message *m,
 static int fill_source_output_info(struct client *client, struct message *m,
 		struct pw_manager_object *o)
 {
+	struct impl *impl = client->impl;
 	struct pw_node_info *info = o->info;
 	struct pw_manager *manager = client->manager;
 	struct pw_manager_object *peer;
@@ -3827,7 +3831,7 @@ static int fill_source_output_info(struct client *client, struct message *m,
 	    (str = spa_dict_lookup(info->props, PW_KEY_CLIENT_ID)) != NULL)
 		client_id = (uint32_t)atoi(str);
 
-	collect_device_info(o, NULL, &dev_info, false);
+	collect_device_info(o, NULL, &dev_info, false, &impl->defs);
 
 	if (!sample_spec_valid(&dev_info.ss) ||
 	    !channel_map_valid(&dev_info.map) ||