output_plugin: replaced output_plugin.get_mixer() with mixer_plugin

The mixer core library is now responsible for creating and managing
the mixer object.  This removes duplicated code from the output
plugins.

src/mixer_all.c

@@ -42,7 +42,7 @@ output_mixer_get_volume(unsigned i)
 	if (!output->enabled)
 		return -1;
 
-	mixer = ao_plugin_get_mixer(output->plugin, output->data);
+	mixer = output->mixer;
 	if (mixer == NULL)
 		return -1;
 
@@ -81,7 +81,7 @@ output_mixer_set_volume(unsigned i, int volume, bool relative)
 	if (!output->enabled)
 		return false;
 
-	mixer = ao_plugin_get_mixer(output->plugin, output->data);
+	mixer = output->mixer;
 	if (mixer == NULL)
 		return false;
 

src/output/alsa_plugin.c

@@ -19,7 +19,6 @@
 
 #include "../output_api.h"
 #include "mixer_list.h"
-#include "mixer_control.h"
 
 #include <glib.h>
 #include <alsa/asoundlib.h>
@@ -70,9 +69,6 @@ struct alsa_data {
 
 	/** the size of one audio frame */
 	size_t frame_size;
-
-	/** the mixer object associated with this output */
-	struct mixer *mixer;
 };
 
 /**
@@ -105,7 +101,6 @@ static void
 alsa_data_free(struct alsa_data *ad)
 {
 	g_free(ad->device);
-	mixer_free(ad->mixer);
 	g_free(ad);
 }
 
@@ -151,7 +146,6 @@ alsa_init(G_GNUC_UNUSED const struct audio_format *audio_format,
 	}
 
 	alsa_configure(ad, param);
-	ad->mixer = mixer_new(&alsa_mixer, param);
 
 	return ad;
 }
@@ -164,14 +158,6 @@ alsa_finish(void *data)
 	alsa_data_free(ad);
 }
 
-static struct mixer *
-alsa_get_mixer(void *data)
-{
-	struct alsa_data *ad = data;
-
-	return ad->mixer;
-}
-
 static bool
 alsa_test_default_device(void)
 {
@@ -400,8 +386,6 @@ alsa_open(void *data, struct audio_format *audio_format, GError **error)
 	int err;
 	bool success;
 
-	mixer_open(ad->mixer);
-
 	bitformat = get_bitformat(audio_format);
 	if (bitformat == SND_PCM_FORMAT_UNKNOWN) {
 		/* sample format is not supported by this plugin -
@@ -484,8 +468,6 @@ alsa_close(void *data)
 		snd_pcm_drain(ad->pcm);
 
 	snd_pcm_close(ad->pcm);
-
-	mixer_close(ad->mixer);
 }
 
 static size_t
@@ -514,9 +496,9 @@ const struct audio_output_plugin alsaPlugin = {
 	.test_default_device = alsa_test_default_device,
 	.init = alsa_init,
 	.finish = alsa_finish,
-	.get_mixer = alsa_get_mixer,
 	.open = alsa_open,
 	.play = alsa_play,
 	.cancel = alsa_cancel,
 	.close = alsa_close,
+	.mixer_plugin = &alsa_mixer,
 };

src/output/oss_plugin.c

@@ -19,7 +19,6 @@
 
 #include "../output_api.h"
 #include "mixer_list.h"
-#include "mixer_control.h"
 
 #include <glib.h>
 
@@ -54,9 +53,6 @@ struct oss_data {
 	unsigned num_supported[3];
 	int *unsupported[3];
 	unsigned num_unsupported[3];
-
-	/** the mixer object associated with this output */
-	struct mixer *mixer;
 };
 
 enum oss_support {
@@ -302,8 +298,6 @@ oss_data_free(struct oss_data *od)
 	g_free(od->unsupported[OSS_CHANNELS]);
 	g_free(od->unsupported[OSS_BITS]);
 
-	mixer_free(od->mixer);
-
 	g_free(od);
 }
 
@@ -372,7 +366,6 @@ oss_open_default(GError **error)
 		if (ret[i] == OSS_STAT_NO_ERROR) {
 			struct oss_data *od = oss_data_new();
 			od->device = default_devices[i];
-			od->mixer = mixer_new(&oss_mixer, NULL);
 			return od;
 		}
 	}
@@ -412,7 +405,6 @@ oss_output_init(G_GNUC_UNUSED const struct audio_format *audio_format,
 	if (device != NULL) {
 		struct oss_data *od = oss_data_new();
 		od->device = device;
-		od->mixer = mixer_new(&oss_mixer, param);
 		return od;
 	}
 
@@ -427,14 +419,6 @@ oss_output_finish(void *data)
 	oss_data_free(od);
 }
 
-static struct mixer *
-oss_get_mixer(void *data)
-{
-	struct oss_data *od = data;
-
-	return od->mixer;
-}
-
 static int
 oss_set_param(struct oss_data *od, unsigned param, int *value)
 {
@@ -562,8 +546,6 @@ oss_output_open(void *data, struct audio_format *audio_format, GError **error)
 
 	*audio_format = od->audio_format;
 
-	mixer_open(od->mixer);
-
 	return ret;
 }
 
@@ -573,7 +555,6 @@ oss_output_close(void *data)
 	struct oss_data *od = data;
 
 	oss_close(od);
-	mixer_close(od->mixer);
 }
 
 static void
@@ -616,9 +597,9 @@ const struct audio_output_plugin oss_output_plugin = {
 	.test_default_device = oss_output_test_default_device,
 	.init = oss_output_init,
 	.finish = oss_output_finish,
-	.get_mixer = oss_get_mixer,
 	.open = oss_output_open,
 	.close = oss_output_close,
 	.play = oss_output_play,
 	.cancel = oss_output_cancel,
+	.mixer_plugin = &oss_mixer,
 };

src/output/pulse_plugin.c

@@ -19,7 +19,6 @@
 
 #include "../output_api.h"
 #include "mixer_list.h"
-#include "mixer_control.h"
 
 #include <glib.h>
 #include <pulse/simple.h>
@@ -29,7 +28,6 @@
 
 struct pulse_data {
 	const char *name;
-	struct mixer *mixer;
 
 	pa_simple *s;
 	char *server;
@@ -62,7 +60,6 @@ static void pulse_free_data(struct pulse_data *pd)
 	g_free(pd->server);
 	g_free(pd->sink);
 	g_free(pd);
-	mixer_free(pd->mixer);
 }
 
 static void *
@@ -78,8 +75,6 @@ pulse_init(G_GNUC_UNUSED const struct audio_format *audio_format,
 	pd->sink = param != NULL
 		? config_dup_block_string(param, "sink", NULL) : NULL;
 
-	pd->mixer=mixer_new(&pulse_mixer, param);
-
 	return pd;
 }
 
@@ -90,15 +85,6 @@ static void pulse_finish(void *data)
 	pulse_free_data(pd);
 }
 
-static struct mixer *
-pulse_get_mixer(void *data)
-{
-	struct pulse_data *pd = data;
-
-	return pd->mixer;
-}
-
-
 static bool pulse_test_default_device(void)
 {
 	pa_simple *s;
@@ -147,7 +133,6 @@ pulse_open(void *data, struct audio_format *audio_format, GError **error_r)
 			    pa_strerror(error));
 		return false;
 	}
-	mixer_open(pd->mixer);
 
 	return true;
 }
@@ -190,9 +175,9 @@ const struct audio_output_plugin pulse_plugin = {
 	.test_default_device = pulse_test_default_device,
 	.init = pulse_init,
 	.finish = pulse_finish,
-	.get_mixer = pulse_get_mixer,
 	.open = pulse_open,
 	.play = pulse_play,
 	.cancel = pulse_cancel,
 	.close = pulse_close,
+	.mixer_plugin = &pulse_mixer,
 };

src/output_command.c

@@ -61,7 +61,7 @@ audio_output_disable_index(unsigned idx)
 	ao->enabled = false;
 	idle_add(IDLE_OUTPUT);
 
-	mixer = ao_plugin_get_mixer(ao->plugin, ao->data);
+	mixer = ao->mixer;
 	if (mixer != NULL) {
 		mixer_close(mixer);
 		idle_add(IDLE_MIXER);

src/output_control.c

@@ -21,6 +21,7 @@
 #include "output_api.h"
 #include "output_internal.h"
 #include "output_thread.h"
+#include "mixer_control.h"
 
 #include <assert.h>
 #include <stdlib.h>
@@ -61,6 +62,8 @@ audio_output_open(struct audio_output *ao,
 		  const struct audio_format *audio_format,
 		  const struct music_pipe *mp)
 {
+	bool open;
+
 	assert(mp != NULL);
 
 	if (ao->fail_timer != NULL) {
@@ -93,10 +96,16 @@ audio_output_open(struct audio_output *ao,
 	if (ao->thread == NULL)
 		audio_output_thread_start(ao);
 
-	if (!ao->open)
+	open = ao->open;
+	if (!open) {
 		ao_command(ao, AO_COMMAND_OPEN);
+		open = ao->open;
+	}
 
-	return ao->open;
+	if (open && ao->mixer != NULL)
+		mixer_open(ao->mixer);
+
+	return open;
 }
 
 bool
@@ -139,6 +148,9 @@ void audio_output_close(struct audio_output *ao)
 {
 	assert(!ao->open || ao->fail_timer == NULL);
 
+	if (ao->mixer != NULL)
+		mixer_close(ao->mixer);
+
 	if (ao->open)
 		ao_command(ao, AO_COMMAND_CLOSE);
 	else if (ao->fail_timer != NULL) {
@@ -158,6 +170,9 @@ void audio_output_finish(struct audio_output *ao)
 		g_thread_join(ao->thread);
 	}
 
+	if (ao->mixer != NULL)
+		mixer_free(ao->mixer);
+
 	ao_plugin_finish(ao->plugin, ao->data);
 
 	notify_deinit(&ao->notify);

src/output_init.c

@@ -22,6 +22,7 @@
 #include "output_internal.h"
 #include "output_list.h"
 #include "audio_parser.h"
+#include "mixer_control.h"
 
 #include <glib.h>
 
@@ -134,5 +135,10 @@ audio_output_init(struct audio_output *ao, const struct config_param *param,
 	if (ao->data == NULL)
 		return false;
 
+	if (plugin->mixer_plugin != NULL)
+		ao->mixer = mixer_new(plugin->mixer_plugin, param);
+	else
+		ao->mixer = NULL;
+
 	return true;
 }

src/output_internal.h

@@ -52,6 +52,13 @@ struct audio_output {
 	 */
 	void *data;
 
+	/**
+	 * The #mixer object associated with this audio output device.
+	 * May be NULL if none is available, or if software volume is
+	 * configured.
+	 */
+	struct mixer *mixer;
+
 	/**
 	 * This flag is true, when the audio_format of this device is
 	 * configured in mpd.conf.

src/output_plugin.h

@@ -66,15 +66,6 @@ struct audio_output_plugin {
 	 */
 	void (*finish)(void *data);
 
-	/**
-	 * Returns the mixer device associated with this audio output.
-	 * This does not actually open the mixer device yet.
-	 *
-	 * @return the mixer object, or NULL if there is no mixer
-	 * attached to this audio output
-	 */
-	struct mixer *(*get_mixer)(void *data);
-
 	/**
 	 * Really open the device.
 	 *
@@ -125,6 +116,14 @@ struct audio_output_plugin {
 	 * for continue to pause
 	 */
 	bool (*pause)(void *data);
+
+	/**
+	 * The mixer plugin associated with this output plugin.  This
+	 * may be NULL if no mixer plugin is implemented.  When
+	 * created, this mixer plugin gets the same #config_param as
+	 * this audio output device.
+	 */
+	const struct mixer_plugin *mixer_plugin;
 };
 
 static inline bool
@@ -150,14 +149,6 @@ ao_plugin_finish(const struct audio_output_plugin *plugin, void *data)
 	plugin->finish(data);
 }
 
-static inline struct mixer *
-ao_plugin_get_mixer(const struct audio_output_plugin *plugin, void *data)
-{
-	return plugin->get_mixer != NULL
-		? plugin->get_mixer(data)
-		: NULL;
-}
-
 static inline bool
 ao_plugin_open(const struct audio_output_plugin *plugin,
 	       void *data, struct audio_format *audio_format,