Add audio-visualizer settings

feat(audio): wire audio-visualizer settings into navigation and menu
feat(audio): add audio-visualizer settings screen with live previews
feat(audio): add audio-visualizer settings strings
fix(audio): move visualizer setting to Account section; render at feed size
feat(audio): add Classic (default) and Static visualiser styles

amethyst/src/main/java/com/vitorpamplona/amethyst/model/AccountSyncedSettingsInternal.kt

@@ -201,6 +201,6 @@ class AccountSecurityPreferencesInternal(
 
 @Serializable
 class AccountMediaPreferencesInternal(
-    // Stored as VisualizerStyle.name; defaults to WAVES.
-    var audioVisualizer: String = "WAVES",
+    // Stored as VisualizerStyle.name; defaults to CLASSIC (the app's classic audio animation).
+    var audioVisualizer: String = "CLASSIC",
 )

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/RenderVideoPlayer.kt

@@ -186,6 +186,7 @@ fun RenderVideoPlayer(
         AudioPlayingAnimation(
             controllerState = controllerState,
             waveform = mediaItem.src.waveformData,
+            mediaId = mediaItem.src.videoUri,
             style = visualizerStyle,
             modifier = Modifier.fillMaxSize().align(Alignment.Center),
             hasBlurhash = hasBlurhash,

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/wavefront/AudioPlayingAnimation.kt

@@ -21,7 +21,8 @@
 package com.vitorpamplona.amethyst.service.playback.composable.wavefront
 
 import androidx.compose.foundation.background
-import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.requiredHeight
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.getValue
@@ -30,14 +31,17 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.dp
 import androidx.media3.common.C
 import androidx.media3.common.Player
 import androidx.media3.common.Tracks
 import com.vitorpamplona.amethyst.commons.audio.AudioVisualizer
+import com.vitorpamplona.amethyst.commons.audio.SyntheticSpectrum
 import com.vitorpamplona.amethyst.commons.audio.VisualizerStyle
 import com.vitorpamplona.amethyst.service.playback.composable.MediaControllerState
 import com.vitorpamplona.amethyst.service.playback.composable.WaveformData
 import com.vitorpamplona.amethyst.service.playback.playerPool.PcmTapRegistry
+import kotlinx.coroutines.flow.flowOf
 
 fun Tracks.isAudio() = groups.isNotEmpty() && groups.none { it.type == C.TRACK_TYPE_VIDEO }
 
@@ -45,6 +49,7 @@ fun Tracks.isAudio() = groups.isNotEmpty() && groups.none { it.type == C.TRACK_T
 fun AudioPlayingAnimation(
     controllerState: MediaControllerState,
     waveform: WaveformData?,
+    mediaId: String,
     style: VisualizerStyle,
     modifier: Modifier = Modifier,
     hasBlurhash: Boolean = false,
@@ -69,23 +74,23 @@ fun AudioPlayingAnimation(
         // NIP-A0 voice notes etc. that ship a precomputed waveform keep their seek bar.
         waveform != null -> Waveform(waveform, controllerState, modifier)
 
+        // The app's classic animated waveform.
+        style == VisualizerStyle.CLASSIC -> FakeWaveformAnimation(mediaControllerState = controllerState, modifier = modifier)
+
+        // A still, non-animated bar graphic for users who prefer no motion.
+        style == VisualizerStyle.STATIC -> {
+            val frozen = remember { flowOf(SyntheticSpectrum.frame(0f, 48)) }
+            AudioVisualizer(style = VisualizerStyle.BARS, spectrum = frozen, modifier = modifier.fillMaxWidth().requiredHeight(72.dp))
+        }
+
         // Visualizer disabled: draw nothing so any blurhash/cover backdrop shows through.
         style == VisualizerStyle.OFF -> Unit
 
+        // Live FFT styles (BARS / WAVES / RADIAL / AURORA).
         else -> {
-            val spectrum = remember(controllerState.controller) { PcmTapRegistry.spectrumFor(controllerState.controller) }
-            if (spectrum != null) {
-                // Dim the cover/blurhash backdrop behind the live visualizer.
-                val drawModifier = if (hasBlurhash) modifier.background(Color.Black.copy(alpha = 0.45f)) else modifier
-                AudioVisualizer(
-                    style = style,
-                    spectrum = spectrum,
-                    modifier = drawModifier.fillMaxSize(),
-                )
-            } else if (!hasBlurhash) {
-                // No live PCM available and no backdrop: keep the decorative fallback.
-                FakeWaveformAnimation(mediaControllerState = controllerState, modifier = modifier)
-            }
+            val spectrum = remember(mediaId) { PcmTapRegistry.spectrumFor(mediaId) }
+            val drawModifier = if (hasBlurhash) modifier.background(Color.Black.copy(alpha = 0.45f)) else modifier
+            AudioVisualizer(style = style, spectrum = spectrum, modifier = drawModifier.fillMaxWidth().requiredHeight(72.dp))
         }
     }
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/playerPool/ExoPlayerBuilder.kt

@@ -22,6 +22,8 @@ package com.vitorpamplona.amethyst.service.playback.playerPool
 
 import android.content.Context
 import androidx.annotation.OptIn
+import androidx.media3.common.MediaItem
+import androidx.media3.common.Player
 import androidx.media3.common.util.UnstableApi
 import androidx.media3.datasource.DataSource
 import androidx.media3.exoplayer.DefaultLoadControl
@@ -67,7 +69,18 @@ class ExoPlayerBuilder(
                 setLoadControl(feedTunedLoadControl())
             }.build()
             .apply {
-                PcmTapRegistry.register(this, sink)
+                PcmTapRegistry.registerPlayer(this, sink)
+                addListener(
+                    object : Player.Listener {
+                        override fun onMediaItemTransition(
+                            mediaItem: MediaItem?,
+                            reason: Int,
+                        ) {
+                            PcmTapRegistry.bind(mediaItem?.mediaId, sink)
+                        }
+                    },
+                )
+                PcmTapRegistry.bind(currentMediaItem?.mediaId, sink)
                 addListener(AspectRatioCacher(MediaAspectRatioCache))
                 addListener(KeepVideosPlaying(this))
                 addListener(CurrentPlayPositionCacher(this, VideoViewedPositionCache))

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/playerPool/ExoPlayerPool.kt

@@ -209,7 +209,7 @@ class ExoPlayerPool(
                 coldPool.add(player)
             }
         } else {
-            PcmTapRegistry.unregister(player)
+            PcmTapRegistry.unregisterPlayer(player)
             player.release() // Release if pool is full.
         }
     }
@@ -225,11 +225,11 @@ class ExoPlayerPool(
                             copy
                         }
                     warmSnapshot.forEach {
-                        PcmTapRegistry.unregister(it.player)
+                        PcmTapRegistry.unregisterPlayer(it.player)
                         it.player.release()
                     }
                     coldPool.forEach {
-                        PcmTapRegistry.unregister(it)
+                        PcmTapRegistry.unregisterPlayer(it)
                         it.release()
                     }
                     coldPool.clear()

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/playerPool/PcmTapRegistry.kt

@@ -38,22 +38,22 @@ import java.util.concurrent.ConcurrentHashMap
 
 /**
  * A Media3 [TeeAudioProcessor.AudioBufferSink] that turns the decoded 16-bit PCM of the
- * currently-playing track into a live [Spectrum] stream ([frames]) via FFT + log binning.
+ * currently-playing track into a live [Spectrum] stream via FFT + log binning, emitting into
+ * whichever per-media-id [output] flow [PcmTapRegistry] has currently bound it to.
  *
- * Only 16-bit PCM is handled; other encodings are ignored. Note that ExoPlayer audio
- * *offload* and *passthrough* modes bypass the audio-processor chain entirely, so no PCM
- * reaches this sink in those modes — the [frames] flow simply stays empty and the
- * visualizer renders idle (it never shows a stale/wrong spectrum, thanks to the replay-cache
- * reset in [flush]). Amethyst does not enable audio offload, so this is not expected in
- * practice.
+ * Only 16-bit PCM is handled; other encodings are ignored. ExoPlayer audio *offload* and
+ * *passthrough* modes bypass the processor chain, so no PCM reaches this sink in those modes —
+ * the bound flow stays empty and the visualizer renders idle (never stale). Amethyst does not
+ * enable offload, so this is not expected in practice.
  */
 @OptIn(UnstableApi::class)
 class SpectrumAudioBufferSink(
     private val fftSize: Int = 1024,
     private val binCount: Int = 48,
 ) : TeeAudioProcessor.AudioBufferSink {
-    // replay = 1 so a renderer subscribing mid-playback gets the latest frame immediately.
-    val frames = MutableSharedFlow<Spectrum>(replay = 1, extraBufferCapacity = 1)
+    /** The per-media-id flow this sink currently feeds; set by [PcmTapRegistry.bind]. */
+    @Volatile
+    var output: MutableSharedFlow<Spectrum>? = null
 
     private val window = AudioWindow.hann(fftSize)
     private val mono = ShortArray(fftSize)
@@ -61,7 +61,7 @@ class SpectrumAudioBufferSink(
     private var channels = 1
     private var encoding = C.ENCODING_PCM_16BIT
 
-    @kotlin.OptIn(ExperimentalCoroutinesApi::class)
+    @OptIn(ExperimentalCoroutinesApi::class)
     override fun flush(
         sampleRateHz: Int,
         channelCount: Int,
@@ -70,9 +70,8 @@ class SpectrumAudioBufferSink(
         this.channels = channelCount.coerceAtLeast(1)
         this.encoding = encoding
         filled = 0
-        // Drop any spectrum from the previously-played track so a freshly subscribing
-        // collector doesn't briefly see the old track's last frame on pooled-player reuse.
-        frames.resetReplayCache()
+        // Drop any spectrum from the previous track so a fresh subscriber doesn't see it on reuse.
+        output?.resetReplayCache()
     }
 
     override fun handleBuffer(buffer: ByteBuffer) {
@@ -89,32 +88,48 @@ class SpectrumAudioBufferSink(
         }
     }
 
-    // Allocates a few short-lived arrays per FFT window (~47/s at 48kHz/1024). Acceptable for
-    // now; pre-allocated working buffers would be the optimization if audio-thread GC shows up.
+    // Allocates a few short-lived arrays per FFT window (~47/s at 48kHz/1024). Acceptable for now;
+    // pre-allocated working buffers would be the optimization if audio-thread GC shows up.
     private fun emitSpectrum() {
         val windowed = AudioWindow.shortsToWindowed(mono, window)
         val mags = Fft.magnitudes(windowed).normalizedToPeak()
-        frames.tryEmit(Spectrum(mags.toLogBins(binCount)))
+        output?.tryEmit(Spectrum(mags.toLogBins(binCount)))
     }
 }
 
-/** Maps each pooled player to its live spectrum stream. */
+/**
+ * Routes each pooled player's decoded-PCM spectrum to a stable, per-media-id flow that the UI can
+ * subscribe to by media URL. The flow is created on demand so a UI subscriber can attach before
+ * playback binds the sink (avoids a compose-vs-playback race).
+ */
 @OptIn(UnstableApi::class)
 object PcmTapRegistry {
-    private val sinks = ConcurrentHashMap<Any, SpectrumAudioBufferSink>()
+    private val flowsByMediaId = ConcurrentHashMap<String, MutableSharedFlow<Spectrum>>()
+    private val sinkByPlayer = ConcurrentHashMap<Any, SpectrumAudioBufferSink>()
 
     fun newSink(): SpectrumAudioBufferSink = SpectrumAudioBufferSink()
 
-    fun register(
+    fun registerPlayer(
         playerKey: Any,
         sink: SpectrumAudioBufferSink,
     ) {
-        sinks[playerKey] = sink
+        sinkByPlayer[playerKey] = sink
     }
 
-    fun unregister(playerKey: Any) {
-        sinks.remove(playerKey)
+    /** Points [sink]'s output at the flow for [mediaId] (the item it is now playing), or detaches it. */
+    fun bind(
+        mediaId: String?,
+        sink: SpectrumAudioBufferSink,
+    ) {
+        sink.output = mediaId?.let { flowFor(it) }
     }
 
-    fun spectrumFor(playerKey: Any): Flow<Spectrum>? = sinks[playerKey]?.frames
+    fun unregisterPlayer(playerKey: Any) {
+        sinkByPlayer.remove(playerKey)?.output = null
+    }
+
+    /** Stable spectrum stream for a media URL. Frames arrive once a player is bound to it and plays. */
+    fun spectrumFor(mediaId: String): Flow<Spectrum> = flowFor(mediaId)
+
+    private fun flowFor(mediaId: String): MutableSharedFlow<Spectrum> = flowsByMediaId.getOrPut(mediaId) { MutableSharedFlow(replay = 1, extraBufferCapacity = 1) }
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/AppNavigation.kt

@@ -170,6 +170,7 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.relays.vanish.VanishEventsS
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.scheduledposts.ScheduledPostsScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.search.SearchScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.settings.AllSettingsScreen
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.settings.AudioVisualizerSettingsScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.settings.BlockedUsersScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.settings.BottomBarSettingsScreen
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.settings.CallSettingsScreen
@@ -375,6 +376,7 @@ fun BuildNavigation(
         composableFromEnd<Route.ComposeSettings> { ComposeSettingsScreen(accountViewModel, nav) }
         composableFromEnd<Route.UserSettings> { UserSettingsScreen(accountViewModel, nav) }
         composableFromEnd<Route.ReactionsSettings> { ReactionsSettingsScreen(accountViewModel, nav) }
+        composableFromEnd<Route.AudioVisualizerSettings> { AudioVisualizerSettingsScreen(accountViewModel, nav) }
         composableFromEnd<Route.BottomBarSettings> { BottomBarSettingsScreen(accountViewModel, nav) }
         composableFromEnd<Route.HomeTabsSettings> { HomeTabsSettingsScreen(accountViewModel, nav) }
         composableFromEnd<Route.ProfileUiSettings> { ProfileUiSettingsScreen(accountViewModel, nav) }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/routes/Routes.kt

@@ -325,6 +325,8 @@ sealed class Route {
 
     @Serializable object ReactionsSettings : Route()
 
+    @Serializable object AudioVisualizerSettings : Route()
+
     @Serializable object BottomBarSettings : Route()
 
     @Serializable object HomeTabsSettings : Route()

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/settings/AudioVisualizerSettingsScreen.kt

@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.screen.loggedIn.settings
+
+import androidx.compose.animation.core.LinearEasing
+import androidx.compose.animation.core.RepeatMode
+import androidx.compose.animation.core.animateFloat
+import androidx.compose.animation.core.infiniteRepeatable
+import androidx.compose.animation.core.rememberInfiniteTransition
+import androidx.compose.animation.core.tween
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.RadioButton
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableFloatStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.vitorpamplona.amethyst.R
+import com.vitorpamplona.amethyst.commons.audio.AudioVisualizer
+import com.vitorpamplona.amethyst.commons.audio.SyntheticSpectrum
+import com.vitorpamplona.amethyst.commons.audio.VisualizerStyle
+import com.vitorpamplona.amethyst.service.playback.composable.wavefront.FakeWaveformAnimation
+import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.topbars.TopBarWithBackButton
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
+import com.vitorpamplona.amethyst.ui.stringRes
+import kotlinx.coroutines.flow.flowOf
+
+@Composable
+fun AudioVisualizerSettingsScreen(
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    Scaffold(
+        topBar = {
+            TopBarWithBackButton(stringRes(id = R.string.audio_visualizer_settings), nav)
+        },
+    ) { padding ->
+        AudioVisualizerSettingsContent(accountViewModel, Modifier.padding(padding))
+    }
+}
+
+@Composable
+fun AudioVisualizerSettingsContent(
+    accountViewModel: AccountViewModel,
+    modifier: Modifier = Modifier,
+) {
+    val selected by accountViewModel.audioVisualizerFlow().collectAsStateWithLifecycle()
+
+    LazyColumn(modifier = modifier.fillMaxWidth()) {
+        item {
+            Text(
+                text = stringRes(R.string.audio_visualizer_settings_description),
+                style = MaterialTheme.typography.bodyMedium,
+                color = Color.Gray,
+                modifier = Modifier.padding(16.dp),
+            )
+        }
+        items(VisualizerStyle.entries) { style ->
+            VisualizerStyleRow(
+                style = style,
+                selected = style == selected,
+                onClick = { accountViewModel.changeAudioVisualizer(style) },
+            )
+        }
+        item { Spacer(Modifier.height(16.dp)) }
+    }
+}
+
+@Composable
+private fun VisualizerStyleRow(
+    style: VisualizerStyle,
+    selected: Boolean,
+    onClick: () -> Unit,
+) {
+    Row(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clickable(onClick = onClick)
+                .padding(horizontal = 16.dp, vertical = 8.dp),
+        verticalAlignment = Alignment.CenterVertically,
+        horizontalArrangement = Arrangement.spacedBy(12.dp),
+    ) {
+        RadioButton(selected = selected, onClick = onClick)
+        Column(Modifier.weight(1f)) {
+            Text(visualizerStyleName(style), style = MaterialTheme.typography.bodyLarge)
+        }
+        Box(
+            modifier =
+                Modifier
+                    .size(width = 120.dp, height = 56.dp)
+                    .clip(RoundedCornerShape(8.dp))
+                    .background(Color(0xFF0C0C10)),
+        ) {
+            when (style) {
+                VisualizerStyle.OFF -> Unit
+                VisualizerStyle.CLASSIC -> {
+                    val transition = rememberInfiniteTransition(label = "classicPreview")
+                    val anim by transition.animateFloat(
+                        initialValue = 0f,
+                        targetValue = 1f,
+                        animationSpec = infiniteRepeatable(tween(1500, easing = LinearEasing), RepeatMode.Restart),
+                        label = "classicProgress",
+                    )
+                    val progress = remember { mutableFloatStateOf(0f) }
+                    progress.floatValue = anim
+                    FakeWaveformAnimation(progress, 40, Modifier.fillMaxWidth().height(56.dp))
+                }
+                VisualizerStyle.STATIC -> {
+                    val frozen = remember { flowOf(SyntheticSpectrum.frame(0f, 48)) }
+                    AudioVisualizer(style = VisualizerStyle.BARS, spectrum = frozen, modifier = Modifier.fillMaxWidth().height(56.dp))
+                }
+                else -> {
+                    val preview = remember { SyntheticSpectrum.flow(48) }
+                    AudioVisualizer(style = style, spectrum = preview, modifier = Modifier.fillMaxWidth().height(56.dp))
+                }
+            }
+        }
+    }
+}
+
+@Composable
+fun visualizerStyleName(style: VisualizerStyle): String =
+    when (style) {
+        VisualizerStyle.CLASSIC -> stringRes(R.string.audio_visualizer_classic)
+        VisualizerStyle.OFF -> stringRes(R.string.audio_visualizer_off)
+        VisualizerStyle.BARS -> stringRes(R.string.audio_visualizer_bars)
+        VisualizerStyle.WAVES -> stringRes(R.string.audio_visualizer_waves)
+        VisualizerStyle.RADIAL -> stringRes(R.string.audio_visualizer_radial)
+        VisualizerStyle.AURORA -> stringRes(R.string.audio_visualizer_aurora)
+        VisualizerStyle.STATIC -> stringRes(R.string.audio_visualizer_static)
+    }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/settings/SettingsCatalogBuilder.kt

@@ -71,6 +71,7 @@ fun buildSettingsCatalog(
                     symEntry(R.string.favorite_dvms_title, MaterialSymbols.AutoAwesome, R.string.favorite_dvms_search_keywords, Route.EditFavoriteAlgoFeeds),
                     symEntry(R.string.reactions, MaterialSymbols.FavoriteBorder, R.string.reactions_search_keywords, Route.UpdateReactionType),
                     symEntry(R.string.video_player_settings, MaterialSymbols.VideoSettings, R.string.video_player_search_keywords, Route.VideoPlayerSettings),
+                    symEntry(R.string.audio_visualizer_settings, MaterialSymbols.MusicNote, R.string.audio_visualizer_search_keywords, Route.AudioVisualizerSettings),
                     symEntry(R.string.zaps, MaterialSymbols.Bolt, R.string.zaps_search_keywords, Route.UpdateZapAmount()),
                     symEntry(R.string.payment_targets, MaterialSymbols.Payment, R.string.payment_targets_search_keywords, Route.EditPaymentTargets),
                     symEntry(R.string.security_filters, MaterialSymbols.Security, R.string.security_filters_search_keywords, Route.SecurityFilters),

amethyst/src/main/res/values/strings.xml

@@ -1526,6 +1526,7 @@
     <string name="favorite_dvms_search_keywords" translatable="false">dvm, data vending machine, algo, algorithm, feeds</string>
     <string name="reactions_search_keywords" translatable="false">emoji, like, reaction</string>
     <string name="video_player_search_keywords" translatable="false">video, player, playback, autoplay, mute</string>
+    <string name="audio_visualizer_search_keywords" translatable="false">audio, visualizer, spectrum, bars, waves, radial, aurora, animation</string>
     <string name="payment_targets_search_keywords" translatable="false">zap split, split, recipients, forward zaps</string>
     <string name="call_settings_search_keywords" translatable="false">webrtc, video call, voice call, calls</string>
     <string name="translations_search_keywords" translatable="false">language, translate, locale</string>
@@ -2336,6 +2337,16 @@
     <string name="video_player_settings_action_cast">Cast to Device</string>
     <string name="video_player_settings_action_cast_description">Send the video to a Chromecast receiver on your Wi-Fi (hidden for local files)</string>
 
+    <string name="audio_visualizer_settings">Audio Visualizer</string>
+    <string name="audio_visualizer_settings_description">Choose the animation shown while audio notes play.</string>
+    <string name="audio_visualizer_off">Off</string>
+    <string name="audio_visualizer_bars">Spectrum Bars</string>
+    <string name="audio_visualizer_waves">Color Waves</string>
+    <string name="audio_visualizer_radial">Radial Ring</string>
+    <string name="audio_visualizer_aurora">Aurora Glow</string>
+    <string name="audio_visualizer_classic">Classic Waveform</string>
+    <string name="audio_visualizer_static">Static Image</string>
+
     <string name="profile_image_of_user">Profile Picture of %1$s</string>
     <string name="relay_info">Relay %1$s</string>
     <string name="expand_relay_list">Expand relay list</string>

amethyst/src/test/java/com/vitorpamplona/amethyst/service/playback/playerPool/SpectrumAudioBufferSinkTest.kt

@@ -23,6 +23,8 @@ package com.vitorpamplona.amethyst.service.playback.playerPool
 import androidx.annotation.OptIn
 import androidx.media3.common.C
 import androidx.media3.common.util.UnstableApi
+import com.vitorpamplona.amethyst.commons.audio.Spectrum
+import kotlinx.coroutines.flow.MutableSharedFlow
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertTrue
 import org.junit.Test
@@ -66,11 +68,13 @@ class SpectrumAudioBufferSinkTest {
     @Test
     fun lowFrequencySineLightsLowBins() {
         val sink = SpectrumAudioBufferSink(fftSize = fftSize, binCount = binCount)
+        val out = MutableSharedFlow<Spectrum>(replay = 1, extraBufferCapacity = 1)
+        sink.output = out
         sink.flush(48000, 1, C.ENCODING_PCM_16BIT)
         sink.handleBuffer(monoPcm(sineShorts(k = 2, n = fftSize)))
 
         val bins =
-            sink.frames.replayCache
+            out.replayCache
                 .last()
                 .bins
         assertEquals(binCount, bins.size)
@@ -80,11 +84,13 @@ class SpectrumAudioBufferSinkTest {
     @Test
     fun highFrequencySineLightsHighBins() {
         val sink = SpectrumAudioBufferSink(fftSize = fftSize, binCount = binCount)
+        val out = MutableSharedFlow<Spectrum>(replay = 1, extraBufferCapacity = 1)
+        sink.output = out
         sink.flush(48000, 1, C.ENCODING_PCM_16BIT)
         sink.handleBuffer(monoPcm(sineShorts(k = 28, n = fftSize)))
 
         val bins =
-            sink.frames.replayCache
+            out.replayCache
                 .last()
                 .bins
         assertTrue("expected high bin to dominate, got ${maxBin(bins)}", maxBin(bins) >= binCount / 2)
@@ -93,11 +99,13 @@ class SpectrumAudioBufferSinkTest {
     @Test
     fun stereoIsDownmixedFromFirstChannel() {
         val sink = SpectrumAudioBufferSink(fftSize = fftSize, binCount = binCount)
+        val out = MutableSharedFlow<Spectrum>(replay = 1, extraBufferCapacity = 1)
+        sink.output = out
         sink.flush(48000, 2, C.ENCODING_PCM_16BIT)
         sink.handleBuffer(interleavedStereoPcm(sineShorts(k = 2, n = fftSize), ShortArray(fftSize)))
 
         val bins =
-            sink.frames.replayCache
+            out.replayCache
                 .last()
                 .bins
         assertTrue(maxBin(bins) < binCount / 2)
@@ -106,22 +114,26 @@ class SpectrumAudioBufferSinkTest {
     @Test
     fun emitsOnlyAfterAFullFftWindowAccumulates() {
         val sink = SpectrumAudioBufferSink(fftSize = fftSize, binCount = binCount)
+        val out = MutableSharedFlow<Spectrum>(replay = 1, extraBufferCapacity = 1)
+        sink.output = out
         sink.flush(48000, 1, C.ENCODING_PCM_16BIT)
         val full = sineShorts(k = 4, n = fftSize)
 
         sink.handleBuffer(monoPcm(full.copyOfRange(0, fftSize / 2)))
-        assertTrue("no frame should emit before a full window", sink.frames.replayCache.isEmpty())
+        assertTrue("no frame should emit before a full window", out.replayCache.isEmpty())
 
         sink.handleBuffer(monoPcm(full.copyOfRange(fftSize / 2, fftSize)))
-        assertEquals(1, sink.frames.replayCache.size)
+        assertEquals(1, out.replayCache.size)
     }
 
     @Test
     fun nonPcm16EncodingEmitsNothing() {
         val sink = SpectrumAudioBufferSink(fftSize = fftSize, binCount = binCount)
+        val out = MutableSharedFlow<Spectrum>(replay = 1, extraBufferCapacity = 1)
+        sink.output = out
         sink.flush(48000, 1, C.ENCODING_PCM_FLOAT)
         sink.handleBuffer(monoPcm(sineShorts(k = 4, n = fftSize)))
 
-        assertTrue("non-16-bit PCM must not emit a spectrum", sink.frames.replayCache.isEmpty())
+        assertTrue("non-16-bit PCM must not emit a spectrum", out.replayCache.isEmpty())
     }
 }

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/audio/VisualizerStyle.kt

@@ -21,15 +21,17 @@
 package com.vitorpamplona.amethyst.commons.audio
 
 enum class VisualizerStyle {
-    OFF,
+    CLASSIC,
     BARS,
     WAVES,
     RADIAL,
     AURORA,
+    STATIC,
+    OFF,
     ;
 
     companion object {
-        val DEFAULT = WAVES
+        val DEFAULT = CLASSIC
 
         fun fromName(name: String?): VisualizerStyle = entries.firstOrNull { it.name == name } ?: DEFAULT
     }

commons/src/commonTest/kotlin/com/vitorpamplona/amethyst/commons/audio/VisualizerRegistryTest.kt

@@ -22,20 +22,31 @@ package com.vitorpamplona.amethyst.commons.audio
 
 import kotlin.test.Test
 import kotlin.test.assertEquals
-import kotlin.test.assertTrue
 
 class VisualizerRegistryTest {
     @Test
-    fun everyStyleHasARenderer() {
-        for (style in VisualizerStyle.entries) {
-            assertEquals(style, VisualizerRegistry.forStyle(style).style)
-        }
+    fun registryCoversTheFiveSpectrumStylesExactlyOnce() {
+        val styles = VisualizerRegistry.all.map { it.style }.toSet()
+        assertEquals(
+            setOf(
+                VisualizerStyle.OFF,
+                VisualizerStyle.BARS,
+                VisualizerStyle.WAVES,
+                VisualizerStyle.RADIAL,
+                VisualizerStyle.AURORA,
+            ),
+            styles,
+        )
+        assertEquals(5, VisualizerRegistry.all.size)
     }
 
     @Test
-    fun registryCoversEveryStyleExactlyOnce() {
-        val styles = VisualizerRegistry.all.map { it.style }.toSet()
-        assertTrue(styles.containsAll(VisualizerStyle.entries.toList()))
-        assertEquals(VisualizerStyle.entries.size, VisualizerRegistry.all.size)
+    fun forStyleReturnsMatchingRendererForSpectrumStylesAndFallsBackForOthers() {
+        for (renderer in VisualizerRegistry.all) {
+            assertEquals(renderer.style, VisualizerRegistry.forStyle(renderer.style).style)
+        }
+        // CLASSIC and STATIC have no spectrum renderer; the dispatcher falls back to OFF.
+        assertEquals(VisualizerStyle.OFF, VisualizerRegistry.forStyle(VisualizerStyle.CLASSIC).style)
+        assertEquals(VisualizerStyle.OFF, VisualizerRegistry.forStyle(VisualizerStyle.STATIC).style)
     }
 }

commons/src/commonTest/kotlin/com/vitorpamplona/amethyst/commons/audio/VisualizerStyleTest.kt

@@ -28,12 +28,12 @@ class VisualizerStyleTest {
     fun parsesByNameWithSafeDefault() {
         assertEquals(VisualizerStyle.WAVES, VisualizerStyle.fromName("WAVES"))
         assertEquals(VisualizerStyle.RADIAL, VisualizerStyle.fromName("RADIAL"))
-        assertEquals(VisualizerStyle.WAVES, VisualizerStyle.fromName("nonsense"))
-        assertEquals(VisualizerStyle.WAVES, VisualizerStyle.fromName(null))
+        assertEquals(VisualizerStyle.CLASSIC, VisualizerStyle.fromName("nonsense"))
+        assertEquals(VisualizerStyle.CLASSIC, VisualizerStyle.fromName(null))
     }
 
     @Test
-    fun defaultIsWaves() {
-        assertEquals(VisualizerStyle.WAVES, VisualizerStyle.DEFAULT)
+    fun defaultIsClassic() {
+        assertEquals(VisualizerStyle.CLASSIC, VisualizerStyle.DEFAULT)
     }
 }