decoder_list: added configuration block "decoder"

The "decoder" configuration block may contain the configuration of one
decoder plugin.

src/conf.c

@@ -210,6 +210,7 @@ void config_global_init(void)
 	registerConfigParam(CONF_ID3V1_ENCODING,                0,     0);
 	registerConfigParam(CONF_METADATA_TO_USE,               0,     0);
 	registerConfigParam(CONF_SAVE_ABSOLUTE_PATHS,           0,     0);
+	registerConfigParam(CONF_DECODER, true, true);
 	registerConfigParam(CONF_GAPLESS_MP3_PLAYBACK,          0,     0);
 }
 

src/conf.h

@@ -64,6 +64,7 @@
 #define CONF_ID3V1_ENCODING             "id3v1_encoding"
 #define CONF_METADATA_TO_USE            "metadata_to_use"
 #define CONF_SAVE_ABSOLUTE_PATHS        "save_absolute_paths_in_playlists"
+#define CONF_DECODER "decoder"
 #define CONF_GAPLESS_MP3_PLAYBACK	"gapless_mp3_playback"
 
 #define CONF_BOOL_UNSET         -1

src/decoder_list.c

@@ -20,6 +20,7 @@
 #include "decoder_plugin.h"
 #include "utils.h"
 #include "config.h"
+#include "conf.h"
 
 #include <glib.h>
 
@@ -185,12 +186,39 @@ void decoder_plugin_print_all_decoders(FILE * fp)
 	fflush(fp);
 }
 
+/**
+ * Find the "decoder" configuration block for the specified plugin.
+ *
+ * @param plugin_name the name of the decoder plugin
+ * @return the configuration block, or NULL if none was configured
+ */
+static const struct config_param *
+decoder_plugin_config(const char *plugin_name)
+{
+	const struct config_param *param = NULL;
+
+	while ((param = config_get_next_param(CONF_DECODER, param)) != NULL) {
+		const char *name =
+			config_get_block_string(param, "plugin", NULL);
+		if (name == NULL)
+			g_error("decoder configuration without 'plugin' name in line %d",
+				param->line);
+
+		if (strcmp(name, plugin_name) == 0)
+			return param;
+	}
+
+	return NULL;
+}
+
 void decoder_plugin_init_all(void)
 {
 	for (unsigned i = 0; i < num_decoder_plugins; ++i) {
 		const struct decoder_plugin *plugin = decoder_plugins[i];
+		const struct config_param *param =
+			decoder_plugin_config(plugin->name);
 
-		if (decoder_plugin_init(plugin, NULL))
+		if (decoder_plugin_init(plugin, param))
 			decoder_plugins_enabled[i] = true;
 	}
 }