new: add playback speed control

core/audioplayer/src/androidMain/kotlin/fr/ajaury/gwenedeg/player/data/AndroidAudioPlayer.kt

@@ -61,6 +61,10 @@ internal class AndroidAudioPlayer(
         player.prepare()
     }
 
+    override fun setSpeed(speed: Float) {
+        player.setPlaybackSpeed(speed)
+    }
+
     override fun play() {
         player.play()
     }

core/audioplayer/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/domain/AudioPlayer.kt

@@ -22,4 +22,7 @@ interface AudioPlayer {
     fun release()
 
     fun load(uri: String)
+
+    /** Sets the playback speed multiplier (e.g. 1.0 for normal speed, 0.5 for half speed). */
+    fun setSpeed(speed: Float)
 }

core/audioplayer/src/iosMain/kotlin/fr/ajaury/gwenedeg/player/data/IosAudioPlayer.kt

@@ -6,14 +6,16 @@ import kotlinx.cinterop.ExperimentalForeignApi
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
+import platform.AVFoundation.AVAudioTimePitchAlgorithmTimeDomain
 import platform.AVFoundation.AVPlayer
 import platform.AVFoundation.AVPlayerItem
 import platform.AVFoundation.AVPlayerItemDidPlayToEndTimeNotification
+import platform.AVFoundation.audioTimePitchAlgorithm
 import platform.AVFoundation.currentItem
 import platform.AVFoundation.currentTime
 import platform.AVFoundation.duration
 import platform.AVFoundation.pause
-import platform.AVFoundation.play
+import platform.AVFoundation.rate
 import platform.AVFoundation.replaceCurrentItemWithPlayerItem
 import platform.AVFoundation.seekToTime
 import platform.CoreMedia.CMTimeGetSeconds
@@ -29,6 +31,7 @@ import kotlin.time.Duration.Companion.seconds
 internal class IosAudioPlayer : AudioPlayer {
     private var player: AVPlayer? = null
     private var endObserver: NSObjectProtocol? = null
+    private var speed: Float = 1f
 
     private val _playbackState = MutableStateFlow(PlaybackState.IDLE)
     override val playbackState: StateFlow<PlaybackState> = _playbackState.asStateFlow()
@@ -63,6 +66,8 @@ internal class IosAudioPlayer : AudioPlayer {
 
         val nsUrl = NSURL.URLWithString(uri) ?: error("Invalid audio URI: $uri")
         val item = AVPlayerItem(uRL = nsUrl)
+        // Time-domain stretching preserves the pitch when the rate is below 1.0.
+        item.audioTimePitchAlgorithm = AVAudioTimePitchAlgorithmTimeDomain
         player = AVPlayer(playerItem = item)
 
         endObserver = NSNotificationCenter.defaultCenter.addObserverForName(
@@ -75,10 +80,18 @@ internal class IosAudioPlayer : AudioPlayer {
     }
 
     override fun play() {
-        player?.play()
+        // Setting a positive rate resumes playback; using the stored speed keeps the chosen tempo.
+        player?.rate = speed
         _playbackState.value = PlaybackState.PLAYING
     }
 
+    override fun setSpeed(speed: Float) {
+        this.speed = speed
+        if (_playbackState.value == PlaybackState.PLAYING) {
+            player?.rate = speed
+        }
+    }
+
     override fun pause() {
         player?.pause()
         _playbackState.value = PlaybackState.PAUSED

core/audioplayer/src/jvmMain/kotlin/fr/ajaury/gwenedeg/player/data/JvmAudioPlayer.kt

@@ -10,6 +10,7 @@ import java.net.URI
 import javax.sound.sampled.AudioFormat
 import javax.sound.sampled.AudioSystem
 import javax.sound.sampled.Clip
+import javax.sound.sampled.FloatControl
 import javax.sound.sampled.LineEvent
 import kotlin.time.Duration
 import kotlin.time.Duration.Companion.microseconds
@@ -26,6 +27,9 @@ internal class JvmAudioPlayer : AudioPlayer {
 
     private var stoppedByUser = false
 
+    private var speed: Float = 1f
+    private var baseSampleRate: Float = 0f
+
     private val _playbackState = MutableStateFlow(PlaybackState.IDLE)
     override val playbackState: StateFlow<PlaybackState> = _playbackState.asStateFlow()
 
@@ -77,6 +81,23 @@ internal class JvmAudioPlayer : AudioPlayer {
             }
             open(decodedInput)
         }
+        baseSampleRate = pcmFormat.sampleRate
+        applySpeed()
+    }
+
+    override fun setSpeed(speed: Float) {
+        this.speed = speed
+        applySpeed()
+    }
+
+    /**
+     * Adjusts the tempo through the clip's sample-rate control. Unlike the other platforms this does
+     * not preserve pitch, and it is a no-op when the mixer does not expose the control.
+     */
+    private fun applySpeed() {
+        val clip = clip ?: return
+        if (baseSampleRate <= 0f || !clip.isControlSupported(FloatControl.Type.SAMPLE_RATE)) return
+        (clip.getControl(FloatControl.Type.SAMPLE_RATE) as FloatControl).value = baseSampleRate * speed
     }
 
     override fun play() {

core/audioplayer/src/webMain/kotlin/fr/ajaury/gwenedeg/player/data/WebAudioPlayer.kt

@@ -12,6 +12,7 @@ import kotlin.time.Duration.Companion.seconds
 
 internal class WebAudioPlayer : AudioPlayer {
     private var audio: HTMLAudioElement? = null
+    private var speed: Float = 1f
 
     private val _playbackState = MutableStateFlow(PlaybackState.IDLE)
     override val playbackState: StateFlow<PlaybackState> = _playbackState.asStateFlow()
@@ -31,12 +32,19 @@ internal class WebAudioPlayer : AudioPlayer {
 
         audio = (document.createElement("audio") as HTMLAudioElement).apply {
             src = uri
+            playbackRate = speed.toDouble()
             addEventListener("play") { _playbackState.value = PlaybackState.PLAYING }
             addEventListener("ended") { _playbackState.value = PlaybackState.ENDED }
             addEventListener("pause") { _playbackState.value = PlaybackState.PAUSED }
         }
     }
 
+    override fun setSpeed(speed: Float) {
+        // Browsers preserve pitch (preservesPitch defaults to true) when changing playbackRate.
+        this.speed = speed
+        audio?.playbackRate = speed.toDouble()
+    }
+
     override fun play() {
         audio?.play()
     }

data/playback/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/data/PlaybackRepositoryImpl.kt

@@ -136,6 +136,10 @@ internal class PlaybackRepositoryImpl(
         audioPlayer.seekTo(position)
     }
 
+    override fun setSpeed(speed: Float) {
+        audioPlayer.setSpeed(speed)
+    }
+
     override fun seekToSentence(sentenceIndex: Int) {
         val matchingSubtitleLine = subtitle.value.lines.getOrNull(sentenceIndex) ?: return
         audioPlayer.seekTo(matchingSubtitleLine.startTime)

data/playback/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/domain/PlaybackRepository.kt

@@ -25,6 +25,8 @@ interface PlaybackRepository {
 
     fun seekTo(position: Duration)
 
+    fun setSpeed(speed: Float)
+
     fun seekToSentence(sentenceIndex: Int)
 
     fun goToPreviousSentence()

data/preferences/src/commonMain/kotlin/fr/ajaury/gwenedeg/preferences/data/PreferencesRepositoryImpl.kt

@@ -1,6 +1,7 @@
 package fr.ajaury.gwenedeg.preferences.data
 
 import fr.ajaury.gwenedeg.preferences.domain.PreferencesRepository
+import fr.ajaury.gwenedeg.preferences.model.PlaybackPreferences
 import fr.ajaury.gwenedeg.preferences.model.SubtitlePreferences
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
@@ -8,14 +9,21 @@ import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.update
 
 internal class PreferencesRepositoryImpl : PreferencesRepository {
-    private val state = MutableStateFlow(SubtitlePreferences())
+    private val subtitleState = MutableStateFlow(SubtitlePreferences())
-    override val subtitlePreferences: StateFlow<SubtitlePreferences> = state.asStateFlow()
+    override val subtitlePreferences: StateFlow<SubtitlePreferences> = subtitleState.asStateFlow()
+
+    private val playbackState = MutableStateFlow(PlaybackPreferences())
+    override val playbackPreferences: StateFlow<PlaybackPreferences> = playbackState.asStateFlow()
 
     override fun setShowTranscription(enabled: Boolean) {
-        state.update { it.copy(showTranscription = enabled) }
+        subtitleState.update { it.copy(showTranscription = enabled) }
     }
 
     override fun setShowTranslation(enabled: Boolean) {
-        state.update { it.copy(showTranslation = enabled) }
+        subtitleState.update { it.copy(showTranslation = enabled) }
+    }
+
+    override fun setPlaybackSpeed(speed: Float) {
+        playbackState.update { it.copy(speed = speed) }
     }
 }

data/preferences/src/commonMain/kotlin/fr/ajaury/gwenedeg/preferences/domain/PreferencesRepository.kt

@@ -1,12 +1,17 @@
 package fr.ajaury.gwenedeg.preferences.domain
 
+import fr.ajaury.gwenedeg.preferences.model.PlaybackPreferences
 import fr.ajaury.gwenedeg.preferences.model.SubtitlePreferences
 import kotlinx.coroutines.flow.StateFlow
 
 interface PreferencesRepository {
     val subtitlePreferences: StateFlow<SubtitlePreferences>
 
+    val playbackPreferences: StateFlow<PlaybackPreferences>
+
     fun setShowTranscription(enabled: Boolean)
 
     fun setShowTranslation(enabled: Boolean)
+
+    fun setPlaybackSpeed(speed: Float)
 }

data/preferences/src/commonMain/kotlin/fr/ajaury/gwenedeg/preferences/model/PlaybackPreferences.kt

@@ -0,0 +1,18 @@
+package fr.ajaury.gwenedeg.preferences.model
+
+/**
+ * User preferences controlling audio playback.
+ *
+ * @property speed playback speed multiplier, clamped between [MIN_SPEED] and [MAX_SPEED] in
+ * [SPEED_STEP] increments. [DEFAULT_SPEED] is the normal, unaltered speed.
+ */
+data class PlaybackPreferences(
+    val speed: Float = DEFAULT_SPEED,
+) {
+    companion object {
+        const val DEFAULT_SPEED = 1f
+        const val MIN_SPEED = 0.5f
+        const val MAX_SPEED = 1f
+        const val SPEED_STEP = 0.1f
+    }
+}

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/PlaybackSpeedBottomSheet.kt

@@ -0,0 +1,100 @@
+package fr.ajaury.gwenedeg.player.ui
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.ModalBottomSheet
+import androidx.compose.material3.SheetState
+import androidx.compose.material3.Slider
+import androidx.compose.material3.Text
+import androidx.compose.material3.rememberModalBottomSheetState
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import fr.ajaury.gwenedeg.preferences.model.PlaybackPreferences
+import fr.ajaury.gwenedeg.theme.GwenedegTheme
+import kotlin.math.roundToInt
+
+/**
+ * Bottom sheet letting the user pick the audio playback speed between
+ * [PlaybackPreferences.MIN_SPEED] and [PlaybackPreferences.MAX_SPEED].
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun PlaybackSpeedBottomSheet(
+    speed: Float,
+    onSpeedChange: (Float) -> Unit = {},
+    onDismiss: () -> Unit = {},
+    sheetState: SheetState = rememberModalBottomSheetState(),
+) {
+    ModalBottomSheet(
+        onDismissRequest = onDismiss,
+        sheetState = sheetState,
+    ) {
+        PlaybackSpeedContent(
+            speed = speed,
+            onSpeedChange = onSpeedChange,
+        )
+    }
+}
+
+@Composable
+private fun PlaybackSpeedContent(
+    speed: Float,
+    onSpeedChange: (Float) -> Unit = {},
+) {
+    // Number of discrete stops strictly between the endpoints (e.g. 0.5..1.0 by 0.1 → 4).
+    val innerSteps = with(PlaybackPreferences) {
+        (((MAX_SPEED - MIN_SPEED) / SPEED_STEP).roundToInt() - 1).coerceAtLeast(0)
+    }
+
+    Column(
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(horizontal = 16.dp)
+            .padding(bottom = 24.dp),
+        verticalArrangement = Arrangement.spacedBy(8.dp),
+    ) {
+        Row(
+            modifier = Modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.SpaceBetween,
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Text(
+                text = "Vitesse de lecture",
+                style = MaterialTheme.typography.titleMedium,
+            )
+            Text(
+                text = formatPlaybackSpeed(speed),
+                style = MaterialTheme.typography.titleMedium,
+                color = MaterialTheme.colorScheme.primary,
+            )
+        }
+        Slider(
+            value = speed,
+            onValueChange = onSpeedChange,
+            valueRange = PlaybackPreferences.MIN_SPEED..PlaybackPreferences.MAX_SPEED,
+            steps = innerSteps,
+        )
+    }
+}
+
+/** Formats a speed multiplier as a short label, e.g. 1.0 → "x1", 0.7 → "x0.7". */
+internal fun formatPlaybackSpeed(speed: Float): String {
+    val tenths = (speed * 10).roundToInt()
+    return if (tenths % 10 == 0) "x${tenths / 10}" else "x${tenths / 10}.${tenths % 10}"
+}
+
+@Preview
+@Composable
+private fun PlaybackSpeedContentPreview() {
+    GwenedegTheme {
+        PlaybackSpeedContent(speed = 0.7f)
+    }
+}

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/PlayerControl.kt

@@ -1,33 +1,24 @@
 package fr.ajaury.gwenedeg.player.ui
 
 import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.size
-import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.Pause
-import androidx.compose.material.icons.filled.PlayArrow
-import androidx.compose.material.icons.filled.Replay
-import androidx.compose.material.icons.filled.SkipNext
-import androidx.compose.material.icons.filled.SkipPrevious
-import androidx.compose.material3.Button
-import androidx.compose.material3.Icon
-import androidx.compose.material3.IconButton
-import androidx.compose.material3.Slider
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import fr.ajaury.gwenedeg.player.model.PlaybackState
 import fr.ajaury.gwenedeg.player.model.PlaybackTiming
+import fr.ajaury.gwenedeg.player.ui.components.NextButton
+import fr.ajaury.gwenedeg.player.ui.components.PlayButton
+import fr.ajaury.gwenedeg.player.ui.components.PlaybackProgress
+import fr.ajaury.gwenedeg.player.ui.components.PreviousButton
+import fr.ajaury.gwenedeg.player.ui.components.SpeedPreferenceButton
+import fr.ajaury.gwenedeg.preferences.model.PlaybackPreferences
 import fr.ajaury.gwenedeg.theme.GwenedegTheme
 
 @Composable
@@ -35,86 +26,68 @@ fun PlayerControl(
     modifier: Modifier = Modifier,
     playbackState: PlaybackState,
     playbackTiming: PlaybackTiming,
+    canGoToPreviousSentence: Boolean,
+    canGoToNextSentence: Boolean,
+    isSpeedActive: Boolean,
+    playbackSpeed: Float,
     onSeek: (Float) -> Unit = {},
     onMainPlayActionButtonClicked: () -> Unit = {},
     onPreviousSentenceClicked: () -> Unit = {},
     onNextSentenceClicked: () -> Unit = {},
-    canGoToPreviousSentence: Boolean = true,
+    onSpeedClicked: () -> Unit = {},
-    canGoToNextSentence: Boolean = true,
 ) {
     Column(
         modifier = modifier.fillMaxWidth(),
         horizontalAlignment = Alignment.CenterHorizontally,
         verticalArrangement = Arrangement.spacedBy(8.dp),
     ) {
-        var seekProgress by remember { mutableStateOf<Float?>(null) }
+        PlaybackProgress(
-        Slider(
+            playbackTiming = playbackTiming,
-            value = seekProgress ?: playbackTiming.progress,
+            onSeek = onSeek,
-            onValueChange = { seekProgress = it },
-            onValueChangeFinished = {
-                seekProgress?.let { fraction ->
-                    if (playbackTiming.durationMs > 0) {
-                        onSeek(fraction)
-                    }
-                }
-                seekProgress = null
-            },
-            modifier = Modifier.fillMaxWidth(),
         )
 
         Row(
+            modifier = Modifier.fillMaxWidth(),
             verticalAlignment = Alignment.CenterVertically,
-            horizontalArrangement = Arrangement.spacedBy(16.dp),
         ) {
-            IconButton(
+            // Left region: the speed button is centered in the space left of the transport group.
-                modifier = Modifier.size(60.dp),
+            Box(
-                enabled = canGoToPreviousSentence,
+                modifier = Modifier.weight(1f),
-                onClick = onPreviousSentenceClicked,
+                contentAlignment = Alignment.Center,
             ) {
-                Icon(
+                SpeedPreferenceButton(
-                    imageVector = Icons.Default.SkipPrevious,
+                    isSpeedActive = isSpeedActive,
-                    contentDescription = "Previous sentence",
+                    playbackSpeed = playbackSpeed,
+                    onSpeedClicked = onSpeedClicked,
                 )
             }
 
-            Button(
+            // Transport group: centered in the full width by the equal-weight cells on either side.
-                modifier = Modifier.size(60.dp),
+            Row(
-                contentPadding = PaddingValues(0.dp),
+                horizontalArrangement = Arrangement.spacedBy(8.dp),
-                onClick = onMainPlayActionButtonClicked,
+                verticalAlignment = Alignment.CenterVertically,
             ) {
-                Icon(
+                PreviousButton(
-                    imageVector = playbackState.toActionIcon(),
+                    canGoToPreviousSentence = canGoToPreviousSentence,
-                    contentDescription = playbackState.toActionContentDescription(),
+                    onPreviousSentenceClicked = onPreviousSentenceClicked,
+                )
+
+                PlayButton(
+                    playbackState = playbackState,
+                    onMainPlayActionButtonClicked = onMainPlayActionButtonClicked,
+                )
+
+                NextButton(
+                    canGoToNextSentence = canGoToNextSentence,
+                    onNextSentenceClicked = onNextSentenceClicked,
                 )
             }
 
-            IconButton(
+            // Right region: mirrors the left weight so the transport group stays centered.
-                modifier = Modifier.size(60.dp),
+            Spacer(modifier = Modifier.weight(1f))
-                enabled = canGoToNextSentence,
-                onClick = onNextSentenceClicked,
-            ) {
-                Icon(
-                    imageVector = Icons.Default.SkipNext,
-                    contentDescription = "Next sentence",
-                )
         }
     }
 }
-}
-
-private fun PlaybackState.toActionIcon(): ImageVector =
-    when (this) {
-        PlaybackState.PLAYING -> Icons.Default.Pause
-        PlaybackState.ENDED -> Icons.Default.Replay
-        PlaybackState.PAUSED, PlaybackState.IDLE -> Icons.Default.PlayArrow
-    }
-
-private fun PlaybackState.toActionContentDescription(): String =
-    when (this) {
-        PlaybackState.PLAYING -> "Pause"
-        PlaybackState.ENDED -> "Replay"
-        PlaybackState.PAUSED, PlaybackState.IDLE -> "Play"
-    }
 
 @Preview
 @Composable
@@ -123,6 +96,10 @@ private fun PlayerControlPreview() {
         PlayerControl(
             playbackState = PlaybackState.PLAYING,
             playbackTiming = PlaybackTiming(positionMs = 1234, durationMs = 5000),
+            canGoToPreviousSentence = true,
+            canGoToNextSentence = true,
+            isSpeedActive = false,
+            playbackSpeed = PlaybackPreferences.DEFAULT_SPEED,
         )
     }
 }
@@ -135,6 +112,24 @@ private fun PlayerControlFirstSentencePreview() {
             playbackState = PlaybackState.PLAYING,
             playbackTiming = PlaybackTiming(positionMs = 1234, durationMs = 5000),
             canGoToPreviousSentence = false,
+            canGoToNextSentence = true,
+            playbackSpeed = PlaybackPreferences.DEFAULT_SPEED,
+            isSpeedActive = false,
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun PlayerControlActiveSpeedPreview() {
+    GwenedegTheme {
+        PlayerControl(
+            playbackState = PlaybackState.PLAYING,
+            playbackTiming = PlaybackTiming(positionMs = 1234, durationMs = 5000),
+            canGoToPreviousSentence = true,
+            canGoToNextSentence = true,
+            playbackSpeed = 0.7f,
+            isSpeedActive = true,
         )
     }
 }
@@ -146,7 +141,10 @@ private fun PlayerControlLastSentencePreview() {
         PlayerControl(
             playbackState = PlaybackState.PLAYING,
             playbackTiming = PlaybackTiming(positionMs = 1234, durationMs = 5000),
+            canGoToPreviousSentence = true,
             canGoToNextSentence = false,
+            playbackSpeed = PlaybackPreferences.DEFAULT_SPEED,
+            isSpeedActive = false,
         )
     }
 }

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/PlayerScreen.kt

@@ -32,6 +32,7 @@ import fr.ajaury.gwenedeg.player.model.PlaybackTiming
 import fr.ajaury.gwenedeg.player.model.PlayerState
 import fr.ajaury.gwenedeg.player.ui.viewmodel.PlayerUiState
 import fr.ajaury.gwenedeg.player.ui.viewmodel.PlayerViewModel
+import fr.ajaury.gwenedeg.preferences.model.PlaybackPreferences
 import fr.ajaury.gwenedeg.preferences.ui.SubtitlePreferencesBottomSheet
 import fr.ajaury.gwenedeg.subtitle.model.SubtitleLine
 import fr.ajaury.gwenedeg.theme.GwenedegTheme
@@ -64,6 +65,7 @@ fun PlayerScreen(
         onNextSentenceClicked = viewModel::goToNextSentence,
         onShowTranscriptionChange = viewModel::setShowTranscription,
         onShowTranslationChange = viewModel::setShowTranslation,
+        onSpeedChange = viewModel::setPlaybackSpeed,
         onBackClicked = onBackClicked,
     )
 }
@@ -79,9 +81,11 @@ fun PlayerScreen(
     onNextSentenceClicked: () -> Unit = {},
     onShowTranscriptionChange: (Boolean) -> Unit = {},
     onShowTranslationChange: (Boolean) -> Unit = {},
+    onSpeedChange: (Float) -> Unit = {},
     onBackClicked: () -> Unit = {},
 ) {
     var showPreferences by remember { mutableStateOf(false) }
+    var showSpeed by remember { mutableStateOf(false) }
 
     Scaffold(
         topBar = {
@@ -146,12 +150,15 @@ fun PlayerScreen(
                 modifier = Modifier.padding(horizontal = 8.dp),
                 playbackState = uiState.playerState.playbackState,
                 playbackTiming = uiState.playerState.playbackTiming,
+                canGoToPreviousSentence = uiState.canGoToPreviousSentence,
+                canGoToNextSentence = uiState.canGoToNextSentence,
+                playbackSpeed = uiState.playbackSpeed,
+                isSpeedActive = uiState.isSpeedActive,
                 onSeek = onSeekToTimePart,
                 onMainPlayActionButtonClicked = onMainPlayActionButtonClicked,
                 onPreviousSentenceClicked = onPreviousSentenceClicked,
                 onNextSentenceClicked = onNextSentenceClicked,
-                canGoToPreviousSentence = uiState.canGoToPreviousSentence,
+                onSpeedClicked = { showSpeed = true },
-                canGoToNextSentence = uiState.canGoToNextSentence,
             )
         }
 
@@ -163,6 +170,14 @@ fun PlayerScreen(
                 onDismiss = { showPreferences = false },
             )
         }
+
+        if (showSpeed) {
+            PlaybackSpeedBottomSheet(
+                speed = uiState.playbackSpeed,
+                onSpeedChange = onSpeedChange,
+                onDismiss = { showSpeed = false },
+            )
+        }
     }
 }
 

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/components/NextButton.kt

@@ -0,0 +1,49 @@
+package fr.ajaury.gwenedeg.player.ui.components
+
+import androidx.compose.foundation.layout.size
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.SkipNext
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import fr.ajaury.gwenedeg.theme.GwenedegTheme
+
+@Composable
+fun NextButton(
+    canGoToNextSentence: Boolean,
+    onNextSentenceClicked: () -> Unit = {},
+) {
+    IconButton(
+        modifier = Modifier.size(60.dp),
+        enabled = canGoToNextSentence,
+        onClick = onNextSentenceClicked,
+    ) {
+        Icon(
+            imageVector = Icons.Default.SkipNext,
+            contentDescription = "Next sentence",
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun NextButtonCanGoToNextSentencePreview() {
+    GwenedegTheme {
+        NextButton(
+            canGoToNextSentence = true,
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun NextButtonCanNotGoToNextSentencePreview() {
+    GwenedegTheme {
+        NextButton(
+            canGoToNextSentence = false,
+        )
+    }
+}

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/components/PlayButton.kt

@@ -0,0 +1,88 @@
+package fr.ajaury.gwenedeg.player.ui.components
+
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.size
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Pause
+import androidx.compose.material.icons.filled.PlayArrow
+import androidx.compose.material.icons.filled.Replay
+import androidx.compose.material3.Button
+import androidx.compose.material3.Icon
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import fr.ajaury.gwenedeg.player.model.PlaybackState
+import fr.ajaury.gwenedeg.theme.GwenedegTheme
+
+@Composable
+fun PlayButton(
+    playbackState: PlaybackState,
+    onMainPlayActionButtonClicked: () -> Unit = {},
+) {
+    Button(
+        modifier = Modifier.size(60.dp),
+        contentPadding = PaddingValues(0.dp),
+        onClick = onMainPlayActionButtonClicked,
+    ) {
+        Icon(
+            imageVector = playbackState.toActionIcon(),
+            contentDescription = playbackState.toActionContentDescription(),
+        )
+    }
+}
+
+private fun PlaybackState.toActionIcon(): ImageVector =
+    when (this) {
+        PlaybackState.PLAYING -> Icons.Default.Pause
+        PlaybackState.ENDED -> Icons.Default.Replay
+        PlaybackState.PAUSED, PlaybackState.IDLE -> Icons.Default.PlayArrow
+    }
+
+private fun PlaybackState.toActionContentDescription(): String =
+    when (this) {
+        PlaybackState.PLAYING -> "Pause"
+        PlaybackState.ENDED -> "Replay"
+        PlaybackState.PAUSED, PlaybackState.IDLE -> "Play"
+    }
+
+@Preview
+@Composable
+private fun PlayButtonPlayingPreview() {
+    GwenedegTheme {
+        PlayButton(
+            playbackState = PlaybackState.PLAYING,
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun PlayButtonPausedPreview() {
+    GwenedegTheme {
+        PlayButton(
+            playbackState = PlaybackState.PAUSED,
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun PlayButtonEndedPreview() {
+    GwenedegTheme {
+        PlayButton(
+            playbackState = PlaybackState.ENDED,
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun PlayButtonIdlePreview() {
+    GwenedegTheme {
+        PlayButton(
+            playbackState = PlaybackState.IDLE,
+        )
+    }
+}

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/components/PlaybackProgress.kt

@@ -0,0 +1,66 @@
+package fr.ajaury.gwenedeg.player.ui.components
+
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.material3.Slider
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import fr.ajaury.gwenedeg.player.model.PlaybackTiming
+import fr.ajaury.gwenedeg.theme.GwenedegTheme
+
+
+@Composable
+fun PlaybackProgress(
+    playbackTiming: PlaybackTiming,
+    onSeek: (Float) -> Unit = {},
+) {
+    var seekProgress by remember { mutableStateOf<Float?>(null) }
+    Slider(
+        value = seekProgress ?: playbackTiming.progress,
+        onValueChange = { seekProgress = it },
+        onValueChangeFinished = {
+            seekProgress?.let { fraction ->
+                if (playbackTiming.durationMs > 0) {
+                    onSeek(fraction)
+                }
+            }
+            seekProgress = null
+        },
+        modifier = Modifier.fillMaxWidth(),
+    )
+}
+
+@Preview
+@Composable
+private fun PlaybackProgressPreview() {
+    GwenedegTheme {
+        PlaybackProgress(
+            playbackTiming = PlaybackTiming(0, 0),
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun PlaybackProgressInProgressPreview() {
+    GwenedegTheme {
+        PlaybackProgress(
+            playbackTiming = PlaybackTiming(7000, 10000),
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun PlaybackProgressEndedPreview() {
+    GwenedegTheme {
+        PlaybackProgress(
+            playbackTiming = PlaybackTiming(10000, 10000),
+        )
+    }
+}
+

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/components/PreviousButton.kt

@@ -0,0 +1,49 @@
+package fr.ajaury.gwenedeg.player.ui.components
+
+import androidx.compose.foundation.layout.size
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.SkipPrevious
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import fr.ajaury.gwenedeg.theme.GwenedegTheme
+
+@Composable
+fun PreviousButton(
+    canGoToPreviousSentence: Boolean,
+    onPreviousSentenceClicked: () -> Unit = {},
+) {
+    IconButton(
+        modifier = Modifier.size(60.dp),
+        enabled = canGoToPreviousSentence,
+        onClick = onPreviousSentenceClicked,
+    ) {
+        Icon(
+            imageVector = Icons.Default.SkipPrevious,
+            contentDescription = "Previous sentence",
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun PreviousButtonCanGoToPreviousSentencePreview() {
+    GwenedegTheme {
+        PreviousButton(
+            canGoToPreviousSentence = true,
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun PreviousButtonCanNotGoToPreviousSentencePreview() {
+    GwenedegTheme {
+        PreviousButton(
+            canGoToPreviousSentence = false,
+        )
+    }
+}

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/components/SpeedPreferenceButton.kt

@@ -0,0 +1,62 @@
+package fr.ajaury.gwenedeg.player.ui.components
+
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.size
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.LocalContentColor
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import fr.ajaury.gwenedeg.player.ui.formatPlaybackSpeed
+import fr.ajaury.gwenedeg.theme.GwenedegTheme
+
+@Composable
+fun SpeedPreferenceButton(
+    isSpeedActive: Boolean,
+    playbackSpeed: Float,
+    onSpeedClicked: () -> Unit = {},
+) {
+    TextButton(
+        modifier = Modifier.size(60.dp),
+        contentPadding = PaddingValues(0.dp),
+        onClick = onSpeedClicked,
+        colors = ButtonDefaults.textButtonColors(
+            contentColor = if (isSpeedActive) {
+                MaterialTheme.colorScheme.primary
+            } else {
+                LocalContentColor.current
+            },
+        ),
+    ) {
+        Text(
+            text = formatPlaybackSpeed(playbackSpeed),
+            style = MaterialTheme.typography.labelLarge,
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun SpeedPreferenceButtonDefaultPreview() {
+    GwenedegTheme {
+        SpeedPreferenceButton(
+            isSpeedActive = false,
+            playbackSpeed = 1f,
+        )
+    }
+}
+
+@Preview
+@Composable
+private fun SpeedPreferenceButtonPreview() {
+    GwenedegTheme {
+        SpeedPreferenceButton(
+            isSpeedActive = true,
+            playbackSpeed = 0.7f,
+        )
+    }
+}

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/viewmodel/PlayerUiState.kt

@@ -2,16 +2,21 @@ package fr.ajaury.gwenedeg.player.ui.viewmodel
 
 import fr.ajaury.gwenedeg.core.model.Phrase
 import fr.ajaury.gwenedeg.player.model.PlayerState
+import fr.ajaury.gwenedeg.preferences.model.PlaybackPreferences
 import fr.ajaury.gwenedeg.preferences.model.SubtitlePreferences
 
 data class PlayerUiState(
     val recordTitle: Phrase = Phrase(transcription = ""),
     val playerState: PlayerState = PlayerState(),
     val subtitlePreferences: SubtitlePreferences = SubtitlePreferences(),
+    val playbackSpeed: Float = PlaybackPreferences.DEFAULT_SPEED,
 ) {
     val canGoToPreviousSentence: Boolean
         get() = playerState.playbackTiming.positionMs > 2000
 
     val canGoToNextSentence: Boolean
         get() = (playerState.currentSubtitleIndex ?: Int.MAX_VALUE) < playerState.subtitleLines.lastIndex
+
+    val isSpeedActive: Boolean
+        get() = playbackSpeed != PlaybackPreferences.DEFAULT_SPEED
 }

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/viewmodel/PlayerViewModel.kt

@@ -8,6 +8,7 @@ import fr.ajaury.gwenedeg.player.domain.AudioSessionManager
 import fr.ajaury.gwenedeg.player.domain.PlaybackRepository
 import fr.ajaury.gwenedeg.player.model.PlaybackState
 import fr.ajaury.gwenedeg.preferences.domain.PreferencesRepository
+import fr.ajaury.gwenedeg.preferences.model.PlaybackPreferences
 import fr.ajaury.gwenedeg.records.domain.RecordRepository
 import fr.ajaury.gwenedeg.records.model.Record
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -17,6 +18,7 @@ import kotlinx.coroutines.flow.WhileSubscribed
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
+import kotlin.math.roundToInt
 import kotlin.time.Duration.Companion.milliseconds
 import kotlin.time.Duration.Companion.seconds
 
@@ -34,11 +36,13 @@ class PlayerViewModel(
         record,
         playbackRepository.playerState,
         preferencesRepository.subtitlePreferences,
-    ) { record, playerState, subtitlePreferences ->
+        preferencesRepository.playbackPreferences,
+    ) { record, playerState, subtitlePreferences, playbackPreferences ->
         PlayerUiState(
             recordTitle = record?.title ?: Phrase(transcription = ""),
             playerState = playerState,
             subtitlePreferences = subtitlePreferences,
+            playbackSpeed = playbackPreferences.speed,
         )
     }.stateIn(
         scope = viewModelScope,
@@ -57,6 +61,7 @@ class PlayerViewModel(
             if (alreadyLoadedRecord != null) {
                 logger.debug("Record $recordId already loaded")
                 playbackRepository.load(record = alreadyLoadedRecord)
+                applyCurrentSpeed()
                 return@launch
             }
 
@@ -67,10 +72,15 @@ class PlayerViewModel(
             }
 
             playbackRepository.load(record = loadedRecord)
+            applyCurrentSpeed()
             record.value = loadedRecord
         }
     }
 
+    private fun applyCurrentSpeed() {
+        playbackRepository.setSpeed(preferencesRepository.playbackPreferences.value.speed)
+    }
+
     fun performMainPlayAction() {
         when (uiState.value.playerState.playbackState) {
             PlaybackState.PLAYING -> playbackRepository.pause()
@@ -97,6 +107,16 @@ class PlayerViewModel(
         playbackRepository.goToNextSentence()
     }
 
+    fun setPlaybackSpeed(speed: Float) {
+        val steppedSpeed = (speed * 10).roundToInt() / 10f
+        val clampedSpeed = steppedSpeed.coerceIn(
+            PlaybackPreferences.MIN_SPEED,
+            PlaybackPreferences.MAX_SPEED,
+        )
+        preferencesRepository.setPlaybackSpeed(clampedSpeed)
+        playbackRepository.setSpeed(clampedSpeed)
+    }
+
     fun setShowTranscription(enabled: Boolean) {
         preferencesRepository.setShowTranscription(enabled)
     }