Preamp for missing replay-gain

src/conf.c

@@ -196,6 +196,7 @@ void config_global_init(void)
 	registerConfigParam(CONF_MIXER_CONTROL,                 0,     0);
 	registerConfigParam(CONF_REPLAYGAIN,                    0,     0);
 	registerConfigParam(CONF_REPLAYGAIN_PREAMP,             0,     0);
+	registerConfigParam(CONF_REPLAYGAIN_MISSING_PREAMP,     0,     0);
 	registerConfigParam(CONF_VOLUME_NORMALIZATION,          0,     0);
 	registerConfigParam(CONF_SAMPLERATE_CONVERTER,          0,     0);
 	registerConfigParam(CONF_AUDIO_BUFFER_SIZE,             0,     0);

src/conf.h

@@ -48,6 +48,7 @@
 #define CONF_MIXER_CONTROL              "mixer_control"
 #define CONF_REPLAYGAIN                 "replaygain"
 #define CONF_REPLAYGAIN_PREAMP          "replaygain_preamp"
+#define CONF_REPLAYGAIN_MISSING_PREAMP  "replaygain_missing_preamp"
 #define CONF_VOLUME_NORMALIZATION       "volume_normalization"
 #define CONF_SAMPLERATE_CONVERTER       "samplerate_converter"
 #define CONF_AUDIO_BUFFER_SIZE          "audio_buffer_size"

src/decoder_api.c

@@ -301,8 +301,7 @@ decoder_data(struct decoder *decoder,
 
 		/* apply replay gain or normalization */
 
-		if (replay_gain_info != NULL &&
-		    replay_gain_mode != REPLAY_GAIN_OFF)
+		if (replay_gain_mode != REPLAY_GAIN_OFF)
 			replay_gain_apply(replay_gain_info, dest, nbytes,
 					  &dc.out_audio_format);
 		else if (normalizationEnabled)

src/replay_gain.c

@@ -38,6 +38,7 @@ static const char *const replay_gain_mode_names[] = {
 enum replay_gain_mode replay_gain_mode = REPLAY_GAIN_OFF;
 
 static float replay_gain_preamp = 1.0;
+static float replay_gain_missing_preamp = 1.0;
 
 void replay_gain_global_init(void)
 {
@@ -73,6 +74,25 @@ void replay_gain_global_init(void)
 
 		replay_gain_preamp = pow(10, f / 20.0);
 	}
+
+	param = config_get_param(CONF_REPLAYGAIN_MISSING_PREAMP);
+
+	if (param) {
+		char *test;
+		float f = strtod(param->value, &test);
+
+		if (*test != '\0') {
+			g_error("Replaygain missing preamp \"%s\" is not a number at "
+				"line %i\n", param->value, param->line);
+		}
+
+		if (f < -15 || f > 15) {
+			g_error("Replaygain missing preamp \"%s\" is not between -15 and"
+				"15 at line %i\n", param->value, param->line);
+		}
+
+		replay_gain_missing_preamp = pow(10, f / 20.0);
+	}
 }
 
 static float calc_replay_gain_scale(float gain, float peak)
@@ -116,19 +136,28 @@ void
 replay_gain_apply(struct replay_gain_info *info, char *buffer, int size,
 		  const struct audio_format *format)
 {
-	if (replay_gain_mode == REPLAY_GAIN_OFF || !info)
+	float scale;
+
+	if (replay_gain_mode == REPLAY_GAIN_OFF)
 		return;
 
-	if (info->scale < 0) {
-		const struct replay_gain_tuple *tuple =
-			&info->tuples[replay_gain_mode];
+	if (info) {
+	    if (info->scale < 0) {
+		    const struct replay_gain_tuple *tuple =
+			    &info->tuples[replay_gain_mode];
 
-		g_debug("computing ReplayGain %s scale with gain %f, peak %f\n",
-			replay_gain_mode_names[replay_gain_mode],
-			tuple->gain, tuple->peak);
+		    g_debug("computing ReplayGain %s scale with gain %f, peak %f\n",
+			    replay_gain_mode_names[replay_gain_mode],
+			    tuple->gain, tuple->peak);
 
-		info->scale = calc_replay_gain_scale(tuple->gain, tuple->peak);
+		    info->scale = calc_replay_gain_scale(tuple->gain, tuple->peak);
+	    }
+	    scale = info->scale;
+	}
+	else {
+	    scale = replay_gain_missing_preamp;
+	    g_debug("ReplayGain is missing, computing scale %f\n", scale);
 	}
 
-	pcm_volume(buffer, size, format, pcm_float_to_volume(info->scale));
+	pcm_volume(buffer, size, format, pcm_float_to_volume(scale));
 }