mixer_plugin: pass audio_output pointer to mixer_plugin.init()

This allows the mixer object to access its associated audio output
object.

src/mixer/alsa_mixer_plugin.c

@@ -52,7 +52,7 @@ alsa_mixer_quark(void)
 }
 
 static struct mixer *
-alsa_mixer_init(const struct config_param *param,
+alsa_mixer_init(G_GNUC_UNUSED void *ao, const struct config_param *param,
 		G_GNUC_UNUSED GError **error_r)
 {
 	struct alsa_mixer *am = g_new(struct alsa_mixer, 1);

src/mixer/oss_mixer_plugin.c

@@ -74,7 +74,8 @@ oss_find_mixer(const char *name)
 }
 
 static struct mixer *
-oss_mixer_init(const struct config_param *param, GError **error_r)
+oss_mixer_init(G_GNUC_UNUSED void *ao, const struct config_param *param,
+	       GError **error_r)
 {
 	struct oss_mixer *om = g_new(struct oss_mixer, 1);
 

src/mixer/pulse_mixer_plugin.c

@@ -212,7 +212,7 @@ context_state_cb(pa_context *context, void *userdata)
 
 
 static struct mixer *
-pulse_mixer_init(const struct config_param *param,
+pulse_mixer_init(G_GNUC_UNUSED void *ao, const struct config_param *param,
 		 G_GNUC_UNUSED GError **error_r)
 {
 	struct pulse_mixer *pm = g_new(struct pulse_mixer,1);

src/mixer/software_mixer_plugin.c

@@ -37,7 +37,8 @@ struct software_mixer {
 };
 
 static struct mixer *
-software_mixer_init(G_GNUC_UNUSED const struct config_param *param,
+software_mixer_init(G_GNUC_UNUSED void *ao,
+		    G_GNUC_UNUSED const struct config_param *param,
 		    G_GNUC_UNUSED GError **error_r)
 {
 	struct software_mixer *sm = g_new(struct software_mixer, 1);

src/mixer_control.c

@@ -27,14 +27,15 @@
 #define G_LOG_DOMAIN "mixer"
 
 struct mixer *
-mixer_new(const struct mixer_plugin *plugin, const struct config_param *param,
+mixer_new(const struct mixer_plugin *plugin, void *ao,
+	  const struct config_param *param,
 	  GError **error_r)
 {
 	struct mixer *mixer;
 
 	assert(plugin != NULL);
 
-	mixer = plugin->init(param, error_r);
+	mixer = plugin->init(ao, param, error_r);
 
 	assert(mixer == NULL || mixer->plugin == plugin);
 

src/mixer_control.h

@@ -34,7 +34,8 @@ struct mixer_plugin;
 struct config_param;
 
 struct mixer *
-mixer_new(const struct mixer_plugin *plugin, const struct config_param *param,
+mixer_new(const struct mixer_plugin *plugin, void *ao,
+	  const struct config_param *param,
 	  GError **error_r);
 
 void

src/mixer_plugin.h

@@ -38,11 +38,14 @@ struct mixer_plugin {
 	/**
          * Alocates and configures a mixer device.
 	 *
+	 * @param ao the pointer returned by audio_output_plugin.init
+	 * @param param the configuration section, or NULL if there is
+	 * no configuration
 	 * @param error_r location to store the error occuring, or
 	 * NULL to ignore errors
 	 * @return a mixer object, or NULL on error
 	 */
-	struct mixer *(*init)(const struct config_param *param,
+	struct mixer *(*init)(void *ao, const struct config_param *param,
 			      GError **error_r);
 
 	/**

src/output_init.c

@@ -89,7 +89,7 @@ audio_output_mixer_type(const struct config_param *param)
 }
 
 static struct mixer *
-audio_output_load_mixer(const struct config_param *param,
+audio_output_load_mixer(void *ao, const struct config_param *param,
 			const struct mixer_plugin *plugin,
 			struct filter *filter_chain,
 			GError **error_r)
@@ -105,10 +105,10 @@ audio_output_load_mixer(const struct config_param *param,
 		if (plugin == NULL)
 			return NULL;
 
-		return mixer_new(plugin, param, error_r);
+		return mixer_new(plugin, ao, param, error_r);
 
 	case MIXER_TYPE_SOFTWARE:
-		mixer = mixer_new(&software_mixer_plugin, NULL, NULL);
+		mixer = mixer_new(&software_mixer_plugin, NULL, NULL, NULL);
 		assert(mixer != NULL);
 
 		filter_chain_append(filter_chain,
@@ -200,7 +200,8 @@ audio_output_init(struct audio_output *ao, const struct config_param *param,
 	if (ao->data == NULL)
 		return false;
 
-	ao->mixer = audio_output_load_mixer(param, plugin->mixer_plugin,
+	ao->mixer = audio_output_load_mixer(ao->data, param,
+					    plugin->mixer_plugin,
 					    ao->filter, &error);
 	if (ao->mixer == NULL && error != NULL) {
 		g_warning("Failed to initialize hardware mixer for '%s': %s",

test/read_mixer.c

@@ -58,7 +58,7 @@ int main(int argc, G_GNUC_UNUSED char **argv)
 
 	g_thread_init(NULL);
 
-	mixer = mixer_new(&alsa_mixer_plugin, NULL, &error);
+	mixer = mixer_new(&alsa_mixer_plugin, NULL, NULL, &error);
 	if (mixer == NULL) {
 		g_printerr("mixer_new() failed: %s\n", error->message);
 		g_error_free(error);