replay_gain: reimplement as a filter plugin

Apply the replay gain in the output thread.  This means a new setting
will be active instantly, without going through the whole music pipe.
And we might have different replay gain settings for each audio output
device.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/output_init.c b/src/output_init.c
index 2ce6b30f..387915dd 100644
--- a/src/output_init.c
+++ b/src/output_init.c
@@ -194,6 +194,17 @@ audio_output_init(struct audio_output *ao, const struct config_param *param,
 	ao->filter = filter_chain_new();
 	assert(ao->filter != NULL);
 
+	/* create the replay_gain filter */
+
+	ao->replay_gain_filter = filter_new(&replay_gain_filter_plugin,
+					    param, NULL);
+	assert(ao->replay_gain_filter != NULL);
+
+	filter_chain_append(ao->filter, ao->replay_gain_filter);
+	ao->replay_gain_serial = 0;
+
+	/* create the normalization filter (if configured) */
+
 	if (config_get_bool(CONF_VOLUME_NORMALIZATION, false)) {
 		struct filter *normalize_filter =
 			filter_new(&normalize_filter_plugin, NULL, NULL);