playback: add dynamic replaygain mode [#7]

Add a "Dynamic" replaygain mode inspired by the FooBar2000 plugin. This will automatically determine whether the playback is in an album or not and use the album gain or track gain accordingly.
2022-01-13 20:15:22 -07:00 · 2022-01-13 20:15:22 -07:00 · ddf2757cb6
commit ddf2757cb6
parent 5359c819bd
7 changed files with 85 additions and 28 deletions
--- a/README.md
+++ b/README.md
@ -63,9 +63,9 @@ I primarily built Auxio for myself, but you can use it too, I guess.

 ## Building

-Auxio relies on a local version of ExoPlayer that enables some extra features. So, the build process is as follows:
+Auxio relies on a custom version of ExoPlayer that enables some extra features. So, the build process is as follows:

-1. Change into the project directory
+1. Enter into the project directory
 2. Run `python3 prebuild.py`, which installs ExoPlayer and it's extensions.
 3. Build the project normally in Android Studio.

--- a/app/src/main/java/org/oxycblt/auxio/playback/system/AudioReactor.kt
+++ b/app/src/main/java/org/oxycblt/auxio/playback/system/AudioReactor.kt
@ -27,6 +27,7 @@ import androidx.media.AudioManagerCompat
 import com.google.android.exoplayer2.metadata.Metadata
 import com.google.android.exoplayer2.metadata.id3.TextInformationFrame
 import com.google.android.exoplayer2.metadata.vorbis.VorbisComment
+import org.oxycblt.auxio.music.Album
 import org.oxycblt.auxio.playback.state.PlaybackStateManager
 import org.oxycblt.auxio.settings.SettingsManager
 import org.oxycblt.auxio.util.getSystemServiceSafe
@ -88,30 +89,54 @@ class AudioReactor(
     * This is based off Vanilla Music's implementation.
     */
    fun applyReplayGain(metadata: Metadata?) {
-        if (settingsManager.replayGainMode == ReplayGainMode.OFF || metadata == null) {
-            logD("ReplayGain is disabled or cannot be determined for this track, resetting volume.")
+        if (metadata == null) {
+            logD("No metadata.")
            volume = 1f
            return
        }

+        // ReplayGain is configurable, so determine what to do based off of the mode.
+        val useAlbumGain: (Gain) -> Boolean = when (settingsManager.replayGainMode) {
+            ReplayGainMode.OFF -> {
+                logD("ReplayGain is off.")
+                volume = 1f
+                return
+            }
+
+            // User wants track gain to be preferred
+            ReplayGainMode.TRACK ->
+                { gain ->
+                    gain.track == 0f
+                }
+
+            ReplayGainMode.ALBUM ->
+                { gain ->
+                    gain.album != 0f
+                }
+
+            ReplayGainMode.DYNAMIC ->
+                { _ ->
+                    playbackManager.parent is Album &&
+                        playbackManager.song?.album == playbackManager.parent
+                }
+        }
        val gain = parseReplayGain(metadata)

-        // Currently we consider both the album and the track gain.
-        var adjust = 0f
-
-        if (gain != null) {
-            // Allow the user to configure a preferred mode for ReplayGain.
-            adjust = if (settingsManager.replayGainMode == ReplayGainMode.TRACK) {
-                if (gain.track != 0f) gain.track else gain.album
+        val adjust = if (gain != null) {
+            if (useAlbumGain(gain)) {
+                logD("Using album gain.")
+                gain.album
            } else {
-                if (gain.album != 0f) gain.album else gain.track
+                logD("Using track gain.")
+                gain.track
            }
+        } else {
+            0f
        }

        // Final adjustment along the volume curve.
        // Ensure this is clamped to 0 or 1 so that it can be used as a volume.
        volume = MathUtils.clamp((10f.pow((adjust / 20f))), 0f, 1f)
-        logD("Applied ReplayGain adjustment: $volume")
    }

    private fun parseReplayGain(metadata: Metadata): Gain? {
@ -126,14 +151,25 @@ class AudioReactor(
        for (i in 0 until metadata.length()) {
            val entry = metadata.get(i)

-            // Sometimes the ReplayGain keys will be lowercase, so make them uppercase.
-            if (entry is TextInformationFrame && entry.description?.uppercase() in REPLAY_GAIN_TAGS) {
-                tags.add(GainTag(entry.description!!.uppercase(), parseReplayGainFloat(entry.value)))
-                continue
+            val key: String?
+            val value: String
+
+            when (entry) {
+                is TextInformationFrame -> {
+                    key = entry.description?.uppercase()
+                    value = entry.value
+                }
+
+                is VorbisComment -> {
+                    key = entry.key
+                    value = entry.value
+                }
+
+                else -> continue
            }

-            if (entry is VorbisComment && entry.key.uppercase() in REPLAY_GAIN_TAGS) {
-                tags.add(GainTag(entry.key.uppercase(), parseReplayGainFloat(entry.value)))
+            if (key in REPLAY_GAIN_TAGS) {
+                tags.add(GainTag(key!!, parseReplayGainFloat(value)))
            }
        }

--- a/app/src/main/java/org/oxycblt/auxio/playback/system/ReplayGainMode.kt
+++ b/app/src/main/java/org/oxycblt/auxio/playback/system/ReplayGainMode.kt
@ -3,13 +3,15 @@ package org.oxycblt.auxio.playback.system
 enum class ReplayGainMode {
    OFF,
    TRACK,
-    ALBUM;
+    ALBUM,
+    DYNAMIC;

    fun toInt(): Int {
        return when (this) {
            OFF -> INT_OFF
            TRACK -> INT_TRACK
            ALBUM -> INT_ALBUM
+            DYNAMIC -> INT_DYNAMIC
        }
    }

@ -17,12 +19,14 @@ enum class ReplayGainMode {
        private const val INT_OFF = 0xA110
        private const val INT_TRACK = 0xA111
        private const val INT_ALBUM = 0xA112
+        private const val INT_DYNAMIC = 0xA113

        fun fromInt(value: Int): ReplayGainMode? {
            return when (value) {
                INT_OFF -> OFF
                INT_TRACK -> TRACK
                INT_ALBUM -> ALBUM
+                INT_DYNAMIC -> DYNAMIC
                else -> null
            }
        }
--- a/app/src/main/res/values/settings.xml
+++ b/app/src/main/res/values/settings.xml
@ -36,12 +36,14 @@
        <item>@string/set_replay_gain_off</item>
        <item>@string/set_replay_gain_track</item>
        <item>@string/set_replay_gain_album</item>
+        <item>@string/set_replay_gain_dynamic</item>
    </array>

    <string-array name="values_replay_gain">
        <item>@integer/replay_gain_off</item>
        <item>@integer/replay_gain_track</item>
        <item>@integer/replay_gain_album</item>
+        <item>@integer/replay_gain_dynamic</item>
    </string-array>

    <integer name="theme_auto">-1</integer>
@ -56,4 +58,5 @@
    <integer name="replay_gain_off">0xA110</integer>
    <integer name="replay_gain_track">0xA111</integer>
    <integer name="replay_gain_album">0xA112</integer>
+    <integer name="replay_gain_dynamic">0xA113</integer>
 </resources>
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@ -85,10 +85,11 @@
    <string name="set_focus_desc">Pause when other audio plays (ex. Calls)</string>
    <string name="set_plug_mgt">Headset focus</string>
    <string name="set_plug_mgt_desc">Play/Pause when the headset connection changes</string>
-    <string name="set_replay_gain">ReplayGain (MP3/FLAC Only)</string>
+    <string name="set_replay_gain">ReplayGain</string>
    <string name="set_replay_gain_off">Off</string>
    <string name="set_replay_gain_track">Prefer track</string>
    <string name="set_replay_gain_album">Prefer album</string>
+    <string name="set_replay_gain_dynamic">Dynamic</string>

    <string name="set_behavior">Behavior</string>
    <string name="set_song_mode">When a song is selected</string>
--- a/info/FAQ.md
+++ b/info/FAQ.md
@ -30,6 +30,19 @@ As per the [Supported ExoPlayer Formats](https://exoplayer.dev/supported-formats
 MP4, MP3, MKA, OGG, WAV, MPEG, AAC on all versions of Android. Auxio also supports FLAC on all versions
 of Android through the use of the ExoPlayer FLAC extension.

+#### ReplayGain isn't working on my music!
+
+This is for a couple reason:
+- Auxio doesn't extract ReplayGain tags for your format. This is the case with MP4 files since there's no
+defined ReplayGain standard for those.
+- Auxio doesn't recognize your ReplayGain tags. This is usually because of a non-standard tag like ID3v2's `RVAD` or
+an unrecognized name.
+
+#### What is dynamic ReplayGain?
+
+Dynamic ReplayGain is a quirk based off the FooBar2000 plugin that dynamically switches from track gain to album
+gain depending on if the current playback is from an album or not.
+
 #### Why are accents lighter/less saturated in dark mode?

 As per the [Material Design Guidelines](https://material.io/design/color/dark-theme.html), accents should be less
--- a/prebuild.py
+++ b/prebuild.py
@ -33,7 +33,7 @@ def sh(cmd):
 exoplayer_path = os.path.join(os.path.abspath(os.curdir), "deps", "exoplayer")

 if os.path.exists(exoplayer_path):
-    reinstall = input(INFO + "info:" + NC + " ExoPlayer is already installed. Would you like to reinstall it? [y/n] ")
+    reinstall = input(INFO + "info:" + NC + " exoplayer is already installed. would you like to reinstall it? [y/n] ")

    if not re.match("[yY][eE][sS]|[yY]", reinstall):
        sys.exit(0)
@ -55,31 +55,31 @@ if ndk_path is None or not os.path.isfile(os.path.join(ndk_path, "ndk_build")):
            candidates.append(entry.path)

    if len(candidates) > 0:
-        print(WARN + "warn:" + NC + " NDK_PATH was not set or invalid. Multiple candidates were found however:")
+        print(WARN + "warn:" + NC + " NDK_PATH was not set or invalid. multiple candidates were found however:")

        for i, candidate in enumerate(candidates):
            print("[" + str(i) + "] " + candidate)

        try:
-            ndk_path = candidates[int(input("Enter the NDK to use [Default 0]: "))]
+            ndk_path = candidates[int(input("Enter the ndk to use [Default 0]: "))]
        except:
            ndk_path = candidates[0]
    else:
-        print(FATAL + "fatal:" + NC + " NDK_PATH is either invalid, or the Android NDK was not installed at a recognized location.")
+        print(FATAL + "fatal:" + NC + " NDK_PATH is either invalid, or the android ndk was not installed at a recognized location.")
        system.exit(1)

 # Now try to install ExoPlayer.
 sh("rm -rf deps")

-print(INFO + "info:" + NC + " Cloning ExoPlayer...")
+print(INFO + "info:" + NC + " cloning ExoPlayer...")
 sh("git clone https://github.com/oxygencobalt/ExoPlayer.git " + exoplayer_path)
 os.chdir(exoplayer_path)
 sh("git checkout release-v2")

 flac_ext_jni_path = os.path.join("extensions", "flac", "src", "main", "jni")
-print(INFO + "info:" + NC + " Installing FLAC extension...")
+print(INFO + "info:" + NC + " installing FLAC extension...")
 os.chdir(flac_ext_jni_path)
 sh('curl "https://ftp.osuosl.org/pub/xiph/releases/flac/flac-' + FLAC_VERSION + '.tar.xz" | tar xJ && mv "flac-' + FLAC_VERSION + '" flac')
 sh(ndk_path + "/ndk-build APP_ABI=all -j4")

-print(OK + "success:" + NC + " Completed pre-build.")
+print(OK + "success:" + NC + " completed pre-build.")