Take R128 header (not) into account while calculating replay gain.

app/src/main/java/ch/blinkenlights/android/vanilla/BastpUtil.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013-2016 Adrian Ulrich <adrian@blinkenlights.ch>
+ * Copyright (C) 2013-2019 Adrian Ulrich <adrian@blinkenlights.ch>
  *
  * 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
@@ -33,6 +33,7 @@ public class BastpUtil {
 	public class GainValues {
 		public float album;
 		public float track;
+		public boolean found;
 	}
 	/**
 	 * LRU cache for ReplayGain values
@@ -45,7 +46,7 @@ public class BastpUtil {
 
 
 	public BastpUtil() {
-		rgCache = new RGLruCache(64); /* Cache up to 64 entries */
+		rgCache = new RGLruCache(64);
 	}
 
 	/**
@@ -75,25 +76,34 @@ public class BastpUtil {
 		// normal replay gain
 		if(tags.containsKey("REPLAYGAIN_TRACK_GAIN")) {
 			gv.track = getFloatFromString((String)((ArrayList)tags.get("REPLAYGAIN_TRACK_GAIN")).get(0));
+			gv.found = true;
 		}
 		if(tags.containsKey("REPLAYGAIN_ALBUM_GAIN")) {
 			gv.album = getFloatFromString((String)((ArrayList)tags.get("REPLAYGAIN_ALBUM_GAIN")).get(0));
+			gv.found = true;
 		}
 
 		// R128 replay gain
 		boolean r128 = false;
 		if(tags.containsKey("R128_BASTP_BASE_GAIN")) {
+			// This is the gain found in the opus header which automatically gets applied by the media framework.
+			// We therefore do not need to include it in our calculation, but we set the 'found' bit and reset
+			// both album and track gain information as an opus file should only ever contain r128 gain infos.
 			float base = getFloatFromString((String)((ArrayList)tags.get("R128_BASTP_BASE_GAIN")).get(0)) / 256.0f;
-			gv.track = base;
+			if (base != 0.0f) {
-			gv.album = base;
+				gv.track = 0;
-			r128 = true;
+				gv.album = 0;
+				gv.found = true;
+			}
 		}
 		if(tags.containsKey("R128_TRACK_GAIN")) {
 			gv.track += getFloatFromString((String)((ArrayList)tags.get("R128_TRACK_GAIN")).get(0)) / 256.0f;
+			gv.found = true;
 			r128 = true;
 		}
 		if(tags.containsKey("R128_ALBUM_GAIN")) {
 			gv.album += getFloatFromString((String)((ArrayList)tags.get("R128_ALBUM_GAIN")).get(0)) / 256.0f;
+			gv.found = true;
 			r128 = true;
 		}
 

app/src/main/java/ch/blinkenlights/android/vanilla/PlaybackService.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012-2018 Adrian Ulrich <adrian@blinkenlights.ch>
+ * Copyright (C) 2012-2019 Adrian Ulrich <adrian@blinkenlights.ch>
  * Copyright (C) 2010, 2011 Christopher Eby <kreed@kreed.org>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -735,33 +735,33 @@ public final class PlaybackService extends Service
 		float adjust = 0f;
 
 		if (mReplayGainAlbumEnabled) {
-			adjust = (rg.track != 0 ? rg.track : adjust); /* do we have track adjustment ? */
+			adjust = (rg.track != 0 ? rg.track : adjust); // Album gain enabled, but we use the track gain as a backup.
-			adjust = (rg.album != 0 ? rg.album : adjust); /* ..or, even better, album adj? */
+			adjust = (rg.album != 0 ? rg.album : adjust); // If album gain is present, we will prefer it.
 		}
 
 		if (mReplayGainTrackEnabled || (mReplayGainAlbumEnabled && adjust == 0)) {
-			adjust = (rg.album != 0 ? rg.album : adjust); /* do we have album adjustment ? */
+			adjust = (rg.album != 0 ? rg.album : adjust); // Track gain enabled, but we use the album gain as a backup.
-			adjust = (rg.track != 0 ? rg.track : adjust); /* ..or, even better, track adj? */
+			adjust = (rg.track != 0 ? rg.track : adjust); // If track gain is present, we will prefer it.
 		}
 
-		if(adjust == 0) {
+		if (!rg.found) {
-			/* No RG value found: decrease volume for untagged song if requested by user */
+			// No replay gain information found: adjust volume if requested by user.
 			adjust = (mReplayGainUntaggedDeBump-150)/10f;
 		} else {
-			/* This song has some replay gain info, we are now going to apply the 'bump' value
+			// This song has some replay gain info, we are now going to apply the 'bump' value
-			** The preferences stores the raw value of the seekbar, that's 0-150
+			// The preferences stores the raw value of the seekbar, that's 0-150
-			** But we want -15 <-> +15, so 75 shall be zero */
+			// But we want -15 <-> +15, so 75 shall be zero.
-			adjust += 2*(mReplayGainBump-75)/10f; /* 2* -> we want +-15, not +-7.5 */
+			adjust += 2*(mReplayGainBump-75)/10f; // 2* -> we want +-15, not +-7.5
 		}
 
 		if(mReplayGainAlbumEnabled == false && mReplayGainTrackEnabled == false) {
-			/* Feature is disabled: Make sure that we are going to 100% volume */
+			// Feature is disabled: Make sure that we are going to 100% volume.
 			adjust = 0f;
 		}
 
 		float rg_result = ((float)Math.pow(10, (adjust/20) ))*mFadeOut;
 		if(rg_result > 1.0f) {
-			rg_result = 1.0f; /* android would IGNORE the change if this is > 1 and we would end up with the wrong volume */
+			rg_result = 1.0f; // Android would IGNORE the change if this is > 1 and we would end up with the wrong volume.
 		} else if (rg_result < 0.0f) {
 			rg_result = 0.0f;
 		}