mixer/software: new mixer which controls filter/volume

Makefile.am

@@ -97,6 +97,7 @@ mpd_headers = \
 	src/event_pipe.h \
 	src/mixer_plugin.h \
 	src/mixer_type.h \
+	src/mixer/software_mixer_plugin.h \
 	src/daemon.h \
 	src/normalize.h \
 	src/compress.h \
@@ -522,7 +523,8 @@ MIXER_API_SRC = \
 	src/mixer_all.c \
 	src/mixer_api.c
 
-MIXER_SRC =
+MIXER_SRC = \
+	src/mixer/software_mixer_plugin.c
 
 if HAVE_ALSA
 OUTPUT_SRC += src/output/alsa_plugin.c
@@ -741,6 +743,8 @@ test_run_output_SOURCES = test/run_output.c \
 	$(MIXER_SRC) \
 	src/filter_plugin.c src/filter/chain_filter_plugin.c \
 	src/filter/convert_filter_plugin.c \
+	src/filter/volume_filter_plugin.c \
+	src/pcm_volume.c \
 	$(OUTPUT_SRC)
 
 test_read_mixer_CPPFLAGS = $(AM_CPPFLAGS) \
@@ -751,6 +755,8 @@ test_read_mixer_LDADD = $(MPD_LIBS) \
 test_read_mixer_SOURCES = test/read_mixer.c \
 	src/conf.c src/buffer2array.c src/utils.c src/log.c \
 	src/mixer_control.c src/mixer_api.c \
+	src/filter_plugin.c \
+	src/filter/volume_filter_plugin.c \
 	$(MIXER_SRC)
 
 endif

src/filter/volume_filter_plugin.c

@@ -25,6 +25,7 @@
 #include "pcm_buffer.h"
 #include "pcm_volume.h"
 #include "audio_format.h"
+#include "player_control.h"
 
 #include <assert.h>
 #include <string.h>

src/mixer/software_mixer_plugin.c

+/*
+ * Copyright (C) 2003-2009 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "software_mixer_plugin.h"
+#include "mixer_api.h"
+#include "filter_plugin.h"
+#include "filter_registry.h"
+#include "filter/volume_filter_plugin.h"
+#include "pcm_volume.h"
+
+#include <assert.h>
+#include <math.h>
+
+struct software_mixer {
+	/** the base mixer class */
+	struct mixer base;
+
+	struct filter *filter;
+
+	unsigned volume;
+};
+
+static struct mixer *
+software_mixer_init(G_GNUC_UNUSED const struct config_param *param)
+{
+	struct software_mixer *sm = g_new(struct software_mixer, 1);
+
+	mixer_init(&sm->base, &software_mixer_plugin);
+
+	sm->filter = filter_new(&volume_filter_plugin, NULL, NULL);
+	assert(sm->filter != NULL);
+
+	sm->volume = 100;
+
+	return &sm->base;
+}
+
+static void
+software_mixer_finish(struct mixer *data)
+{
+	struct software_mixer *sm = (struct software_mixer *)data;
+
+	g_free(sm);
+}
+
+static bool
+software_mixer_open(struct mixer *data)
+{
+	struct software_mixer *sm = (struct software_mixer *)data;
+
+	(void)sm;
+	return true;
+}
+
+static void
+software_mixer_close(struct mixer *data)
+{
+	struct software_mixer *sm = (struct software_mixer *)data;
+
+	(void)sm;
+}
+
+static int
+software_mixer_get_volume(struct mixer *mixer)
+{
+	struct software_mixer *sm = (struct software_mixer *)mixer;
+
+	return sm->volume;
+}
+
+static bool
+software_mixer_set_volume(struct mixer *mixer, unsigned volume)
+{
+	struct software_mixer *sm = (struct software_mixer *)mixer;
+
+	assert(volume <= 100);
+
+	sm->volume = volume;
+
+	if (volume >= 100)
+		volume = PCM_VOLUME_1;
+	else if (volume > 0)
+		volume = pcm_float_to_volume((exp(volume / 25.0) - 1) /
+					     (54.5981500331F - 1));
+
+	volume_filter_set(sm->filter, volume);
+	return true;
+}
+
+const struct mixer_plugin software_mixer_plugin = {
+	.init = software_mixer_init,
+	.finish = software_mixer_finish,
+	.open = software_mixer_open,
+	.close = software_mixer_close,
+	.get_volume = software_mixer_get_volume,
+	.set_volume = software_mixer_set_volume,
+	.global = true,
+};
+
+struct filter *
+software_mixer_get_filter(struct mixer *mixer)
+{
+	struct software_mixer *sm = (struct software_mixer *)mixer;
+
+	assert(sm->base.plugin == &software_mixer_plugin);
+
+	return sm->filter;
+}

src/mixer/software_mixer_plugin.h

+/*
+ * Copyright (C) 2003-2009 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef SOFTWARE_MIXER_PLUGIN_H
+#define SOFTWARE_MIXER_PLUGIN_H
+
+struct mixer;
+struct filter;
+
+/**
+ * Returns the (volume) filter associated with this mixer.  All users
+ * of this mixer plugin should install this filter.
+ */
+struct filter *
+software_mixer_get_filter(struct mixer *mixer);
+
+#endif

src/mixer_list.h

@@ -25,6 +25,7 @@
 #ifndef MPD_MIXER_LIST_H
 #define MPD_MIXER_LIST_H
 
+extern const struct mixer_plugin software_mixer_plugin;
 extern const struct mixer_plugin alsa_mixer;
 extern const struct mixer_plugin oss_mixer;
 extern const struct mixer_plugin pulse_mixer;

test/read_mixer.c

@@ -19,6 +19,8 @@
 
 #include "mixer_control.h"
 #include "mixer_list.h"
+#include "filter_registry.h"
+#include "pcm_volume.h"
 
 #include <glib.h>
 
@@ -26,6 +28,22 @@
 #include <string.h>
 #include <unistd.h>
 
+const struct filter_plugin *
+filter_plugin_by_name(G_GNUC_UNUSED const char *name)
+{
+	assert(false);
+	return NULL;
+}
+
+bool
+pcm_volume(G_GNUC_UNUSED void *buffer, G_GNUC_UNUSED int length,
+	   G_GNUC_UNUSED const struct audio_format *format,
+	   G_GNUC_UNUSED int volume)
+{
+	assert(false);
+	return false;
+}
+
 int main(int argc, G_GNUC_UNUSED char **argv)
 {
 	struct mixer *mixer;