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Fix FLAC playback in float output mode #125

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Merged
lostf1sh merged 1 commit into from
Sep 12, 2026
Merged

Fix FLAC playback in float output mode #125

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18 changes: 14 additions & 4 deletions app/src/main/java/com/lostf1sh/pixelplayeross/data/service/player/AudioDecoderPolicy.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,7 @@ package com.lostf1sh.pixelplayeross.data.service.player

import androidx.media3.common.MimeTypes
import androidx.media3.common.util.UnstableApi
import com.lostf1sh.pixelplayeross.data.model.AudioOutputMode
import java.util.Locale

@androidx.annotation.OptIn(UnstableApi::class)
Expand All @@ -13,12 +14,21 @@ internal object AudioDecoderPolicy {
AUDIO_MIDI
)

fun shouldUseExtensionRenderer(mimeType: String): Boolean {
return extensionOnlyMimeTypes.any { it.equals(mimeType, ignoreCase = true) }
fun shouldUseExtensionRenderer(mimeType: String, outputMode: AudioOutputMode): Boolean {
// Some platform FLAC decoders produce corrupt audio when Media3 requests PCM_FLOAT
// (reported on the Galaxy S25 Ultra, issue #122). FFmpeg can decode FLAC directly to
// float PCM without that platform negotiation. Keep the normal decoder order in the
// integer output modes, where the reporter confirmed playback works.
return (outputMode.usesFloatOutput && MimeTypes.AUDIO_FLAC.equals(mimeType, ignoreCase = true)) ||
extensionOnlyMimeTypes.any { it.equals(mimeType, ignoreCase = true) }
}

fun <T> selectPlatformDecoders(mimeType: String, decoderInfos: List<T>): List<T> {
return if (shouldUseExtensionRenderer(mimeType)) {
fun <T> selectPlatformDecoders(
mimeType: String,
decoderInfos: List<T>,
outputMode: AudioOutputMode
): List<T> {
return if (shouldUseExtensionRenderer(mimeType, outputMode)) {
emptyList()
} else {
decoderInfos
Expand Down
13 changes: 8 additions & 5 deletions app/src/main/java/com/lostf1sh/pixelplayeross/data/service/player/DualPlayerEngine.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -990,22 +990,25 @@ class DualPlayerEngine @Inject constructor(
}

private fun buildPlayer(): ExoPlayer {
// Decoder selection happens on the playback thread. Keep it tied to this player's sink
// even while a mode change is rebuilding the players.
val outputMode = audioOutputMode
val mediaCodecSelector = MediaCodecSelector { mimeType, requiresSecureDecoder, requiresTunnelingDecoder ->
val decoderInfos = MediaCodecSelector.DEFAULT.getDecoderInfos(
mimeType,
requiresSecureDecoder,
requiresTunnelingDecoder
)

AudioDecoderPolicy.selectPlatformDecoders(mimeType, decoderInfos)
AudioDecoderPolicy.selectPlatformDecoders(mimeType, decoderInfos, outputMode)
}
val renderersFactory = object : DefaultRenderersFactory(context) {
override fun buildAudioSink(
context: Context,
enableFloatOutput: Boolean,
enableAudioOutputPlaybackParams: Boolean
): AudioSink {
if (audioOutputMode.usesUnmodifiedMedia3AudioSink) {
if (outputMode.usesUnmodifiedMedia3AudioSink) {
// Android's audio policy may
// grant a DIRECT thread for a compatible device/format, or safely fall back
// to the mixed path. This deliberately does not promise exclusive output.
Expand All @@ -1018,7 +1021,7 @@ class DualPlayerEngine @Inject constructor(
) { "Media3 did not create its default AudioSink" }
}
return DefaultAudioSink.Builder(context)
.setEnableFloatOutput(audioOutputMode.usesFloatOutput)
.setEnableFloatOutput(outputMode.usesFloatOutput)
.setEnableAudioOutputPlaybackParameters(enableAudioOutputPlaybackParams)
.setAudioProcessorChain(
DefaultAudioSink.DefaultAudioProcessorChain(
Expand Down Expand Up @@ -1056,7 +1059,7 @@ class DualPlayerEngine @Inject constructor(
out: ArrayList<Renderer>
) {
}
}.setEnableAudioFloatOutput(audioOutputMode.usesFloatOutput)
}.setEnableAudioFloatOutput(outputMode.usesFloatOutput)
.setMediaCodecSelector(mediaCodecSelector)
.setEnableDecoderFallback(true)
.setExtensionRendererMode(DefaultRenderersFactory.EXTENSION_RENDERER_MODE_ON)
Expand Down Expand Up @@ -1126,7 +1129,7 @@ class DualPlayerEngine @Inject constructor(
.setMediaSourceFactory(DefaultMediaSourceFactory(resolvingFactory, extractorsFactory))
.setLoadControl(loadControl)
.build().apply {
if (!audioOutputMode.usesUnmodifiedMedia3AudioSink) {
if (!outputMode.usesUnmodifiedMedia3AudioSink) {
sharedAudioSessionIdOrNull()?.let { setAudioSessionId(it) }
}
setAudioAttributes(audioAttributes, false)
Expand Down
54 changes: 45 additions & 9 deletions app/src/test/java/com/lostf1sh/pixelplayeross/data/service/player/AudioDecoderPolicyTest.kt
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@@ -1,38 +1,74 @@
package com.lostf1sh.pixelplayeross.data.service.player

import androidx.media3.common.MimeTypes
import com.lostf1sh.pixelplayeross.data.model.AudioOutputMode
import com.google.common.truth.Truth.assertThat
import org.junit.jupiter.api.Test
import org.junit.jupiter.params.ParameterizedTest
import org.junit.jupiter.params.provider.EnumSource

class AudioDecoderPolicyTest {

@Test
fun selectPlatformDecoders_routesAlacToExtensionRenderer() {
@ParameterizedTest
@EnumSource(AudioOutputMode::class)
fun selectPlatformDecoders_routesAlacToExtensionRenderer(outputMode: AudioOutputMode) {
val decoders = listOf("c2.qti.alac.decoder", "c2.android.alac.decoder")

val selected = AudioDecoderPolicy.selectPlatformDecoders(MimeTypes.AUDIO_ALAC, decoders)
val selected = AudioDecoderPolicy.selectPlatformDecoders(MimeTypes.AUDIO_ALAC, decoders, outputMode)

assertThat(selected).isEmpty()
}

@Test
fun selectPlatformDecoders_routesMidiToExtensionRenderer() {
@ParameterizedTest
@EnumSource(AudioOutputMode::class)
fun selectPlatformDecoders_routesMidiToExtensionRenderer(outputMode: AudioOutputMode) {
val decoders = listOf("platform-midi-decoder")

val selected = AudioDecoderPolicy.selectPlatformDecoders(MimeTypes.AUDIO_EXOPLAYER_MIDI, decoders)
val selected = AudioDecoderPolicy.selectPlatformDecoders(MimeTypes.AUDIO_EXOPLAYER_MIDI, decoders, outputMode)

assertThat(selected).isEmpty()
}

@Test
fun selectPlatformDecoders_preservesMedia3OrderForCoreFormats() {
@ParameterizedTest
@EnumSource(AudioOutputMode::class)
fun selectPlatformDecoders_preservesMedia3OrderForCoreFormats(outputMode: AudioOutputMode) {
val decoders = listOf("c2.android.aac.decoder", "c2.qti.aac.decoder")

val selected = AudioDecoderPolicy.selectPlatformDecoders(MimeTypes.AUDIO_AAC, decoders)
val selected = AudioDecoderPolicy.selectPlatformDecoders(MimeTypes.AUDIO_AAC, decoders, outputMode)

assertThat(selected).containsExactlyElementsIn(decoders).inOrder()
}

@Test
fun selectPlatformDecoders_routesFlacToExtensionRendererForFloatOutput() {
val decoders = listOf("c2.qti.flac.decoder", "c2.android.flac.decoder")

val selected = AudioDecoderPolicy.selectPlatformDecoders(
MimeTypes.AUDIO_FLAC, decoders, AudioOutputMode.PCM_FLOAT
)

assertThat(selected).isEmpty()
}

@ParameterizedTest
@EnumSource(value = AudioOutputMode::class, names = ["SYSTEM_DEFAULT", "DIRECT"])
fun selectPlatformDecoders_preservesFlacDecodersForIntegerOutput(outputMode: AudioOutputMode) {
val decoders = listOf("c2.qti.flac.decoder", "c2.android.flac.decoder")

val selected = AudioDecoderPolicy.selectPlatformDecoders(MimeTypes.AUDIO_FLAC, decoders, outputMode)

assertThat(selected).containsExactlyElementsIn(decoders).inOrder()
}

@Test
fun selectPlatformDecoders_matchesFlacMimeTypeIgnoringCase() {
val selected = AudioDecoderPolicy.selectPlatformDecoders(
"AUDIO/FLAC", listOf("c2.qti.flac.decoder"), AudioOutputMode.PCM_FLOAT
)

assertThat(selected).isEmpty()
}

@Test
fun isLikelyHardwareDecoder_marksSoftwareRenderersAsSoftware() {
assertThat(AudioDecoderPolicy.isLikelyHardwareDecoder("OMX.google.aac.decoder")).isFalse()
Expand Down