diff --git a/spa/include/spa/param/audio/raw-json.h b/spa/include/spa/param/audio/raw-json.h
index 282e76ed5..7ef1b27f3 100644
--- a/spa/include/spa/param/audio/raw-json.h
+++ b/spa/include/spa/param/audio/raw-json.h
@@ -29,7 +29,7 @@ extern "C" {
 
 SPA_API_AUDIO_RAW_JSON int
 spa_audio_parse_position_n(const char *str, size_t len,
-		uint32_t *position, uint32_t max_channels, uint32_t *n_channels)
+		uint32_t *position, uint32_t max_position, uint32_t *n_channels)
 {
 	struct spa_json iter;
         char v[256];
@@ -38,9 +38,10 @@ spa_audio_parse_position_n(const char *str, size_t len,
         if (spa_json_begin_array_relax(&iter, str, len) <= 0)
                 return 0;
 
-        while (spa_json_get_string(&iter, v, sizeof(v)) > 0 &&
-		channels < max_channels) {
-                position[channels++] = spa_type_audio_channel_from_short_name(v);
+        while (spa_json_get_string(&iter, v, sizeof(v)) > 0) {
+		if (channels < max_position)
+	                position[channels] = spa_type_audio_channel_from_short_name(v);
+		channels++;
         }
 	*n_channels = channels;
 	return channels;
diff --git a/spa/plugins/alsa/alsa-pcm.c b/spa/plugins/alsa/alsa-pcm.c
index bad6da9fe..2d9492e95 100644
--- a/spa/plugins/alsa/alsa-pcm.c
+++ b/spa/plugins/alsa/alsa-pcm.c
@@ -243,7 +243,7 @@ static int position_to_string(struct channel_map *map, char *val, size_t len)
 	uint32_t i, o = 0;
 	int r;
 	o += snprintf(val, len, "[ ");
-	for (i = 0; i < map->channels; i++) {
+	for (i = 0; i < map->n_pos; i++) {
 		r = snprintf(val+o, len-o, "%s%s", i == 0 ? "" : ", ",
 				spa_debug_type_find_short_name(spa_type_audio_channel,
 					map->pos[i]));
@@ -1645,7 +1645,7 @@ skip_channels:
 		} else {
 			const struct channel_map *map = NULL;
 			spa_pod_builder_int(b, min);
-			if (state->default_pos.channels == min) {
+			if (state->default_pos.n_pos == min) {
 				map = &state->default_pos;
 				spa_log_debug(state->log, "%p: using provided default", state);
 			} else if (min <= 8) {
@@ -1655,7 +1655,7 @@ skip_channels:
 			if (map) {
 				spa_pod_builder_prop(b, SPA_FORMAT_AUDIO_position, 0);
 				spa_pod_builder_push_array(b, &f[0]);
-				for (i = 0; i < map->channels; i++) {
+				for (i = 0; i < map->n_pos; i++) {
 					spa_log_debug(state->log, "%p: position %zd %d", state, i, map->pos[i]);
 					spa_pod_builder_id(b, map->pos[i]);
 				}
diff --git a/spa/plugins/alsa/alsa-pcm.h b/spa/plugins/alsa/alsa-pcm.h
index 09b5140b9..8b8a07721 100644
--- a/spa/plugins/alsa/alsa-pcm.h
+++ b/spa/plugins/alsa/alsa-pcm.h
@@ -72,7 +72,7 @@ struct buffer {
 #define BW_PERIOD	(3 * SPA_NSEC_PER_SEC)
 
 struct channel_map {
-	uint32_t channels;
+	uint32_t n_pos;
 	uint32_t pos[MAX_CHANNELS];
 };
 
@@ -315,7 +315,7 @@ void spa_alsa_emit_port_info(struct state *state, bool full);
 
 static inline void spa_alsa_parse_position(struct channel_map *map, const char *val, size_t len)
 {
-	spa_audio_parse_position_n(val, len, map->pos, SPA_N_ELEMENTS(map->pos), &map->channels);
+	spa_audio_parse_position_n(val, len, map->pos, SPA_N_ELEMENTS(map->pos), &map->n_pos);
 }
 
 static inline uint32_t spa_alsa_parse_rates(uint32_t *rates, uint32_t max, const char *val, size_t len)
diff --git a/spa/plugins/filter-graph/filter-graph.c b/spa/plugins/filter-graph/filter-graph.c
index bb7f24831..ce0765f83 100644
--- a/spa/plugins/filter-graph/filter-graph.c
+++ b/spa/plugins/filter-graph/filter-graph.c
@@ -232,16 +232,17 @@ struct impl {
 	float *discard_data;
 };
 
-static inline void print_channels(char *buffer, size_t max_size, uint32_t n_channels, uint32_t *positions)
+static inline void print_channels(char *buffer, size_t max_size, uint32_t n_positions, uint32_t *positions)
 {
 	uint32_t i;
 	struct spa_strbuf buf;
 
 	spa_strbuf_init(&buf, buffer, max_size);
 	spa_strbuf_append(&buf, "[");
-	for (i = 0; i < n_channels; i++) {
+	for (i = 0; i < n_positions; i++) {
 		spa_strbuf_append(&buf, "%s%s", i ? "," : "",
 			spa_type_audio_channel_to_short_name(positions[i]));
+
 	}
 	spa_strbuf_append(&buf, "]");
 }