diff --git a/src/mixer/pulse_mixer.c b/src/mixer/pulse_mixer.c
index 9ecf73354..899ab5446 100644
--- a/src/mixer/pulse_mixer.c
+++ b/src/mixer/pulse_mixer.c
@@ -31,11 +31,14 @@
 
 struct pulse_mixer {
 	struct mixer base;
+
 	const char *server;
 	const char *sink;
 	const char *output_name;
+
 	uint32_t index;
-	bool	online;
+	bool online;
+
 	struct pa_context *context;
 	struct pa_threaded_mainloop *mainloop;
 	struct pa_cvolume volume;
@@ -48,19 +51,22 @@ sink_input_cb(G_GNUC_UNUSED pa_context *context, const pa_sink_input_info *i,
 {
 
 	struct pulse_mixer *pm = userdata;
+
 	if (eol) {
 		g_debug("eol error sink_input_cb");
 		return;
 	}
 
-	if (!i) {
+	if (i == NULL) {
 		g_debug("Sink input callback failure");
 		return;
 	}
+
 	g_debug("sink input cb %s, index %d ",i->name,i->index);
-	if(strcmp(i->name,pm->output_name)==0) {
-		pm->index=i->index;
-		pm->online=true;
+
+	if (strcmp(i->name,pm->output_name) == 0) {
+		pm->index = i->index;
+		pm->online = true;
 		pm->volume = i->volume;
 	} else
 		g_debug("bad name");
@@ -72,15 +78,17 @@ sink_input_vol(G_GNUC_UNUSED pa_context *context, const pa_sink_input_info *i,
 {
 
 	struct pulse_mixer *pm = userdata;
+
 	if (eol) {
 		g_debug("eol error sink_input_vol");
 		return;
 	}
 
-	if (!i) {
+	if (i == NULL) {
 		g_debug("Sink input callback failure");
 		return;
 	}
+
 	g_debug("sink input vol %s, index %d ", i->name, i->index);
 	pm->volume = i->volume;
 }
@@ -91,17 +99,21 @@ subscribe_cb(G_GNUC_UNUSED pa_context *c, pa_subscription_event_type_t t,
 {
 
 	struct pulse_mixer *pm = userdata;
+
 	g_debug("subscribe call back");
+
 	switch (t & PA_SUBSCRIPTION_EVENT_FACILITY_MASK) {
 	case PA_SUBSCRIPTION_EVENT_SINK_INPUT:
 		if ((t & PA_SUBSCRIPTION_EVENT_TYPE_MASK) ==
 		    PA_SUBSCRIPTION_EVENT_REMOVE &&
 		    pm->index == idx)
-			pm->online =false;
+			pm->online = false;
 		else {
 			pa_operation *o;
 
-			if (!(o = pa_context_get_sink_input_info(pm->context, idx, sink_input_cb, pm))) {
+			o = pa_context_get_sink_input_info(pm->context, idx,
+							   sink_input_cb, pm);
+			if (o == NULL) {
 				g_debug("pa_context_get_sink_input_info() failed");
 				return;
 			}
@@ -116,26 +128,31 @@ static void
 context_state_cb(pa_context *context, void *userdata)
 {
 	struct pulse_mixer *pm = userdata;
+
 	switch (pa_context_get_state(context)) {
 	case PA_CONTEXT_READY: {
 		pa_operation *o;
 
 		pa_context_set_subscribe_callback(context, subscribe_cb, pm);
 
-		if (!(o = pa_context_subscribe(context, (pa_subscription_mask_t)
-					       (PA_SUBSCRIPTION_MASK_SINK_INPUT), NULL, NULL))) {
+		o = pa_context_subscribe(context,
+					 (pa_subscription_mask_t)PA_SUBSCRIPTION_MASK_SINK_INPUT,
+					 NULL, NULL);
+		if (o == NULL) {
 			g_debug("pa_context_subscribe() failed");
 			return;
 		}
+
 		pa_operation_unref(o);
 
-
-		if (!(o = pa_context_get_sink_input_info_list(context, sink_input_cb, pm))) {
+		o = pa_context_get_sink_input_info_list(context,
+							sink_input_cb, pm);
+		if (o == NULL) {
 			g_debug("pa_context_get_sink_input_info_list() failed");
 			return;
 		}
-		pa_operation_unref(o);
 
+		pa_operation_unref(o);
 
 		pa_threaded_mainloop_signal(pm->mainloop, 0);
 		break;
@@ -160,7 +177,7 @@ pulse_mixer_init(const struct config_param *param)
 	struct pulse_mixer *pm = g_new(struct pulse_mixer,1);
 	mixer_init(&pm->base, &pulse_mixer);
 
-	pm->online=false;
+	pm->online = false;
 
 	pm->server = config_get_block_string(param, "server", NULL);
 	pm->sink = config_get_block_string(param, "sink", NULL);
@@ -213,18 +230,21 @@ static bool
 pulse_mixer_open(G_GNUC_UNUSED struct mixer *data)
 {
 	struct pulse_mixer *pm = (struct pulse_mixer *) data;
+
 	g_debug("pulse mixer open");
 
 	pm->index = 0;
 	pm->online = false;
 
-	if(!(pm->mainloop = pa_threaded_mainloop_new())) {
+	pm->mainloop = pa_threaded_mainloop_new();
+	if (pm->mainloop == NULL) {
 		g_debug("failed mainloop");
 		return false;
 	}
 
-	if(!(pm->context = pa_context_new(pa_threaded_mainloop_get_api(pm->mainloop),
-					  "Mixer mpd"))) {
+	pm->context = pa_context_new(pa_threaded_mainloop_get_api(pm->mainloop),
+				     "Mixer mpd");
+	if (pm->context == NULL) {
 		pa_threaded_mainloop_stop(pm->mainloop);
 		pa_threaded_mainloop_free(pm->mainloop);
 		g_debug("failed context");
@@ -245,7 +265,7 @@ pulse_mixer_open(G_GNUC_UNUSED struct mixer *data)
 static void
 pulse_mixer_close(G_GNUC_UNUSED struct mixer *data)
 {
-	struct pulse_mixer *pm=(struct pulse_mixer *) data;
+	struct pulse_mixer *pm = (struct pulse_mixer *) data;
 
 	pa_threaded_mainloop_stop(pm->mainloop);
 	pa_context_disconnect(pm->context);
@@ -258,18 +278,20 @@ pulse_mixer_close(G_GNUC_UNUSED struct mixer *data)
 static int
 pulse_mixer_get_volume(struct mixer *mixer)
 {
-	struct pulse_mixer *pm=(struct pulse_mixer *) mixer;
+	struct pulse_mixer *pm = (struct pulse_mixer *) mixer;
 	int ret;
 	pa_operation *o;
 
 	g_debug("get_volume %s",
 		pm->online == TRUE ? "online" : "offline");
-	if(pm->online) {
-		if (!(o = pa_context_get_sink_input_info(pm->context, pm->index,
-							 sink_input_vol, pm))) {
+	if (pm->online) {
+		o = pa_context_get_sink_input_info(pm->context, pm->index,
+						   sink_input_vol, pm);
+		if (o == NULL) {
 			g_debug("pa_context_get_sink_input_info() failed");
 			return false;
 		}
+
 		pa_operation_unref(o);
 
 		ret = (int)((100*(pa_cvolume_avg(&pm->volume)+1))/PA_VOLUME_NORM);
@@ -283,14 +305,17 @@ pulse_mixer_get_volume(struct mixer *mixer)
 static bool
 pulse_mixer_set_volume(struct mixer *mixer, unsigned volume)
 {
-	struct pulse_mixer *pm=(struct pulse_mixer *) mixer;
-	pa_operation *o;
-	if (pm->online) {
-		pa_cvolume_set(&pm->volume, pm->volume.channels,
-				(pa_volume_t)(volume)*PA_VOLUME_NORM/100+0.5);
+	struct pulse_mixer *pm = (struct pulse_mixer *) mixer;
 
-		if (!(o = pa_context_set_sink_input_volume(pm->context, pm->index,
-							   &pm->volume, NULL, NULL))) {
+	if (pm->online) {
+		pa_operation *o;
+
+		pa_cvolume_set(&pm->volume, pm->volume.channels,
+				(pa_volume_t)volume * PA_VOLUME_NORM / 100 + 0.5);
+
+		o = pa_context_set_sink_input_volume(pm->context, pm->index,
+						     &pm->volume, NULL, NULL);
+		if (o == NULL) {
 			g_debug("pa_context_set_sink_input_volume() failed");
 			return false;
 		}