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Fix Android stream audio backpressure without blocking video

master
evgeny 4 days ago
parent
commit
0fdc6e435b
  1. 143
      tools/chatgui-android/app/src/main/java/com/utun/chat/data/StreamAudioOutput.kt
  2. 79
      tools/chatgui-android/app/src/main/java/com/utun/chat/data/StreamPlayerEngine.kt
  3. 133
      tools/chatgui-android/app/src/test/java/com/utun/chat/data/StreamAudioOutputTest.kt

143
tools/chatgui-android/app/src/main/java/com/utun/chat/data/StreamAudioOutput.kt

@ -0,0 +1,143 @@
package com.utun.chat.data
import android.media.AudioAttributes
import android.media.AudioFormat
import android.media.AudioTrack
import android.os.Build
/** Один player worker владеет устройством и единственным недописанным PCM.
* Native уже учёл выданные кадры: остаток нельзя терять или переставлять до сброса всей шкалы. */
internal class StreamAudioOutput(
private val open: () -> Sink = { AndroidSink() },
private val log: (String) -> Unit = {}
) {
internal interface Sink {
val threshold: Int
val head: Long
val description: String
fun write(pcm: ShortArray, offset: Int, count: Int): Int
fun pause()
fun play()
fun close()
}
private class AndroidSink : Sink {
private val track = AudioTrack.Builder()
.setAudioAttributes(AudioAttributes.Builder().setUsage(AudioAttributes.USAGE_MEDIA)
.setContentType(AudioAttributes.CONTENT_TYPE_MOVIE).build())
.setAudioFormat(AudioFormat.Builder().setSampleRate(48000).setChannelMask(AudioFormat.CHANNEL_OUT_STEREO)
.setEncoding(AudioFormat.ENCODING_PCM_16BIT).build())
.setBufferSizeInBytes(AudioTrack.getMinBufferSize(48000, AudioFormat.CHANNEL_OUT_STEREO,
AudioFormat.ENCODING_PCM_16BIT).coerceAtLeast(3840)).setTransferMode(AudioTrack.MODE_STREAM).build()
init {
try {
check(track.state == AudioTrack.STATE_INITIALIZED) { "AudioTrack initialization failed" }
// API 26..30 не умеет уменьшать порог отдельно от аппаратного буфера.
if (Build.VERSION.SDK_INT >= 31) track.setStartThresholdInFrames(1)
} catch (e: Exception) { track.release(); throw e }
}
override val threshold: Int get() = if (Build.VERSION.SDK_INT >= 31)
minOf(track.startThresholdInFrames, track.bufferSizeInFrames) else track.bufferSizeInFrames
override val head: Long get() = track.playbackHeadPosition.toLong() and 0xffffffffL
override val description: String get() = "state=${track.state} playState=${track.playState} " +
"buffer=${track.bufferSizeInFrames} threshold=$threshold underruns=${track.underrunCount}"
override fun write(pcm: ShortArray, offset: Int, count: Int) = track.write(pcm, offset, count, AudioTrack.WRITE_NON_BLOCKING)
override fun pause() = track.pause()
override fun play() = track.play()
override fun close() = track.release()
}
private var sink: Sink? = null
private var pending: ShortArray? = null
private var offset = 0
private var padding = false
private var padded = 0L
private var previousHead = 0L
private var headEpoch = 0L
private var deviceHead = 0L
private var stalledSince = -1L
private var openedAt = 0L
private var paused = false
private val silence = ShortArray(960)
var written = 0L
private set
var played = 0L
private set
val pendingFrames: Int get() = if (padding) 0 else ((pending?.size ?: 0) - offset) / 2
val leadUs: Long get() = (written - played + pendingFrames) * 1_000_000 / 48000
val drained: Boolean get() = pendingFrames == 0 && played == written
val description: String get() = "written=$written played=$played pending=$pendingFrames padded=$padded " +
"head=$deviceHead paused=$paused ${sink?.description ?: "device=closed"}"
/** Не экстраполируем старый timestamp: при остановке устройства media clock также стоит. */
private fun poll(now: Long) {
val s = sink ?: return
val raw = s.head
if (raw < previousHead) {
check(previousHead - raw > 0x80000000L) { "AudioTrack head regressed $previousHead->$raw; $description" }
headEpoch += 0x100000000L
}
previousHead = raw
val head = headEpoch + raw
if (head > deviceHead) {
if (deviceHead == 0L) log("audio started delayMs=${(now - openedAt) / 1_000_000} $description")
stalledSince = -1
}
deviceHead = head
played = head.coerceAtMost(written)
}
/** Ровно одна неблокирующая запись за итерацию; ожидание устройства не задерживает video pump. */
fun step(now: Long, hold: Boolean, pull: () -> ShortArray?, finished: () -> Boolean) {
poll(now)
if (paused != hold) {
if (hold) sink?.pause() else sink?.play()
paused = hold; stalledSince = -1
log("audio ${if (hold) "paused" else "resumed"} $description")
}
if (hold) return
if (pending == null && written - played < maxOf(960, sink?.threshold ?: 1)) {
val pcm = pull()
if (pcm != null) {
check(pcm.isNotEmpty() && pcm.size <= 960 && pcm.size % 2 == 0) { "Invalid stream PCM size=${pcm.size}" }
if (sink == null) {
sink = open(); openedAt = now; sink!!.play()
log("audio opened ${sink!!.description}")
}
pending = pcm; offset = 0; padding = false
}
}
val s = sink ?: return
// Короткий EOF должен пересечь порог старых AudioTrack даже после underrun.
// Тишина идёт только после всего PCM; played ограничен written и не сдвигает media PTS.
if (pending == null && finished() && played < written && padded < s.threshold) {
val frames = minOf(480L, s.threshold - padded).toInt()
pending = if (frames == 480) silence else ShortArray(frames * 2)
offset = 0; padding = true
if (padded == 0L) log("audio draining threshold=${s.threshold} $description")
}
var blocked = false
pending?.let { pcm ->
val count = s.write(pcm, offset, pcm.size - offset)
check(count >= 0 && count <= pcm.size - offset && count % 2 == 0) { "AudioTrack write=$count; $description" }
blocked = count == 0
offset += count
if (padding) padded += count / 2 else written += count / 2
if (offset == pcm.size) { pending = null; offset = 0; padding = false }
}
poll(now)
// До достаточного заполнения ожидание сети не является зависанием устройства.
val expectedProgress = written + padded - deviceHead >= s.threshold || blocked
if (!expectedProgress) stalledSince = -1
else if (stalledSince < 0) stalledSince = now
else check(now - stalledSince < 2_000_000_000) {
"AudioTrack made no playback progress for ${(now - stalledSince) / 1_000_000}ms; $description"
}
}
fun close() {
val s = sink
sink = null; pending = null; offset = 0; padding = false
s?.close()
}
}

79
tools/chatgui-android/app/src/main/java/com/utun/chat/data/StreamPlayerEngine.kt

@ -1,9 +1,5 @@
package com.utun.chat.data
import android.media.AudioAttributes
import android.media.AudioFormat
import android.media.AudioTimestamp
import android.media.AudioTrack
import android.media.MediaCodec
import android.media.MediaCodecInfo
import android.media.MediaCodecList
@ -44,28 +40,24 @@ class StreamPlayerEngine(private val group: Long, private val source: Long, priv
private fun play(surface: Surface) {
var decoder: MediaCodec? = null
var track: AudioTrack? = null
fun audioOutput() = StreamAudioOutput(log = { LogManager.addLog("INFO", "stream", "viewer id=$id $it") })
var audio = audioOutput()
var playback = 0L
lateinit var video: StreamDecodePump<Frame>
var waitingKey = true
var audioEnabled = false
var opened = false
var ended = false
var pausedAudio = false
var videoRevision = 0L
var position = -1L
var ready = -1L
var needsAudio = true
var written = 0L
var previousHead = 0L
var headEpoch = 0L
var generation = 0L
var playbackStarted = false
var eosQueued = false
var endUntil = 0L
var reported = 0L
var deadline = System.nanoTime() + 10_000_000_000
val timestamp = AudioTimestamp()
val info = MediaCodec.BufferInfo()
var clockState: LongArray? = null
@ -134,57 +126,21 @@ class StreamPlayerEngine(private val group: Long, private val source: Long, priv
mutableStatus.value = R.string.stream_waiting_key
}
fun resetTimeline(request: Boolean) {
try { track?.pause(); track?.flush(); track?.release() }
try { audio.close() }
catch (e: Exception) { LogManager.addLog("WARN", "stream", "audio reset id=$id: ${e.message}") }
track = null; pausedAudio = false; written = 0; previousHead = 0; headEpoch = 0
audio = audioOutput()
if (playback != 0L) NativeLib.streamPlaybackClose(playback)
playback = 0; position = -1; generation = 0; needsAudio = true; clockState = null; playbackStarted = false
resetVideo(); deadline = System.nanoTime() + 10_000_000_000
if (request) check(NativeLib.streamResync(id)) { "Media resync refused" }
}
fun playedFrames(now: Long): Long {
val t = track ?: return 0
val raw = t.playbackHeadPosition.toLong() and 0xffffffffL
if (raw < previousHead) headEpoch += 0x100000000L
previousHead = raw
val head = headEpoch + raw
if (pausedAudio || !t.getTimestamp(timestamp)) return head.coerceAtMost(written)
var frames = timestamp.framePosition
if (frames <= 0xffffffffL) {
frames += headEpoch
if (frames - head > 0x80000000L) frames -= 0x100000000L
if (head - frames > 0x80000000L) frames += 0x100000000L
}
return (frames + (now - timestamp.nanoTime).coerceAtLeast(0) * 48000 / 1_000_000_000).coerceIn(0, written)
}
fun writePcm(pcm: ShortArray) {
if (track == null) {
track = AudioTrack.Builder().setAudioAttributes(AudioAttributes.Builder().setUsage(AudioAttributes.USAGE_MEDIA)
.setContentType(AudioAttributes.CONTENT_TYPE_MOVIE).build()).setAudioFormat(AudioFormat.Builder()
.setSampleRate(48000).setChannelMask(AudioFormat.CHANNEL_OUT_STEREO).setEncoding(AudioFormat.ENCODING_PCM_16BIT).build())
.setBufferSizeInBytes(AudioTrack.getMinBufferSize(48000, AudioFormat.CHANNEL_OUT_STEREO,
AudioFormat.ENCODING_PCM_16BIT).coerceAtLeast(3840)).setTransferMode(AudioTrack.MODE_STREAM).build()
check(track!!.state == AudioTrack.STATE_INITIALIZED); track!!.play()
LogManager.addLog("INFO", "stream", "audio output id=$id bufferFrames=${track!!.bufferSizeInFrames} stereo=1")
}
val until = System.nanoTime() + 100_000_000
var offset = 0
while (running && offset < pcm.size) {
val count = track!!.write(pcm, offset, pcm.size - offset, AudioTrack.WRITE_NON_BLOCKING)
check(count >= 0 && count % 2 == 0) { "AudioTrack write=$count" }
if (count > 0) { offset += count; written += count / 2 }
else { check(System.nanoTime() < until) { "AudioTrack stalled" }; Thread.sleep(2) }
}
}
video = createVideoPump()
try {
check(NativeLib.streamOpen(id, group, source, audio = true, epoch = epoch)) { "Viewer open refused" }
while (running && surface.isValid) {
check(NativeLib.isReady()) { "Core stopped" }
observeStatus(NativeLib.streamStatus(id))
val now = System.nanoTime()
val played = playedFrames(now)
val deviceLead = (written - played).coerceAtLeast(0) * 1_000_000 / 48000
val deviceLead = audio.leadUs
for (work in 0 until 4) {
video.step(position, System.nanoTime() / 1000)
val audioAhead = if (audioEnabled && needsAudio) deviceLead + 80000 else -1L
@ -245,24 +201,17 @@ class StreamPlayerEngine(private val group: Long, private val source: Long, priv
LogManager.addLog("INFO", "video", "viewer first decoded frame id=$id revision=$videoRevision " +
"PTS=${video.firstOutputPts} inputs=${video.inputCount} decoderLeadUs=${video.decoderLeadUs}")
}
if (playbackStarted && playback != 0L && audioEnabled && !pausedAudio) {
val head = playedFrames(System.nanoTime())
val t = track
val prime = t == null || (head == 0L && written < t.bufferSizeInFrames)
if (prime || written - head < 960) {
NativeLib.streamPlaybackPull(playback, 480, if (ended) Long.MAX_VALUE else ready)?.let { writePcm(it) }
}
}
if (playbackStarted && playback != 0L && ready >= 0) {
val lateVideo = !video.ended && (video.firstOutputPts == null
|| (video.oldestSubmittedPts >= 0 && video.oldestSubmittedPts < position - 10000))
if (lateVideo && track != null && !pausedAudio) { track!!.pause(); pausedAudio = true }
if (pausedAudio && !lateVideo) { track!!.play(); pausedAudio = false }
val head = playedFrames(System.nanoTime())
val audioEmpty = audioEnabled && written > 0 && head >= written && !ended
if (audioEnabled) audio.step(System.nanoTime(), lateVideo,
pull = { NativeLib.streamPlaybackPull(playback, 480, if (ended) Long.MAX_VALUE else ready) },
finished = { ended && NativeLib.streamPlaybackEmpty(playback) })
val head = audio.played
val audioEmpty = audioEnabled && head >= audio.written && !ended
clockState = NativeLib.streamPlaybackUpdate(playback, System.nanoTime() / 1000, head,
if (ended) ready.coerceAtLeast(position) else ready,
maxOf(deviceLead + 10000, video.decoderLeadUs + video.framePeriodUs), lateVideo || audioEmpty)
maxOf(audio.leadUs + 10000, video.decoderLeadUs + video.framePeriodUs), lateVideo || audioEmpty)
check(clockState != null) { "Playback timeline failed" }
position = clockState!![0]; needsAudio = clockState!![5] != 0L
}
@ -277,7 +226,7 @@ class StreamPlayerEngine(private val group: Long, private val source: Long, priv
check(!video.ended || video.firstOutputPts != null || video.inputCount == 0L) { "Decoder ended without producing an image" }
}
if (ended && video.input == null && (decoder == null || video.ended) && NativeLib.streamPlaybackEmpty(playback)
&& playedFrames(System.nanoTime()) >= written) {
&& audio.drained) {
if (endUntil == 0L) endUntil = System.nanoTime() + 100_000_000
if (System.nanoTime() >= endUntil) { mutableStatus.value = R.string.stream_ended; break }
}
@ -287,7 +236,7 @@ class StreamPlayerEngine(private val group: Long, private val source: Long, priv
"decoded=${video.outputCount} shown=${video.shown} discarded=${video.discarded} input=${video.input != null} " +
"output=${video.output?.pts} inflight=${video.inflight} decoderLeadUs=${video.decoderLeadUs} " +
"clock=$position reserve=${clockState?.get(1)} minimum=${clockState?.get(2)} " +
"tempo=${clockState?.get(3)} written=$written waitingKey=$waitingKey")
"tempo=${clockState?.get(3)} ${audio.description} waitingKey=$waitingKey")
}
Thread.sleep(5)
}
@ -300,7 +249,7 @@ class StreamPlayerEngine(private val group: Long, private val source: Long, priv
NativeLib.streamStop(id)
try { decoder?.stop(); decoder?.release() }
catch (e: Exception) { LogManager.addLog("WARN", "video", "decoder release id=$id: ${e.message}") }
try { track?.stop(); track?.release() }
try { audio.close() }
catch (e: Exception) { LogManager.addLog("WARN", "stream", "audio release id=$id: ${e.message}") }
if (playback != 0L) NativeLib.streamPlaybackClose(playback)
val until = System.nanoTime() + 500_000_000

133
tools/chatgui-android/app/src/test/java/com/utun/chat/data/StreamAudioOutputTest.kt

@ -0,0 +1,133 @@
package com.utun.chat.data
import org.junit.Assert.*
import org.junit.Test
import java.util.ArrayDeque
class StreamAudioOutputTest {
private class Device(override val threshold: Int = 1) : StreamAudioOutput.Sink {
override var head = 0L
override val description: String get() = "fake threshold=$threshold"
val samples = ArrayList<Short>()
var limit = 960
var calls = 0
var paused = false
var closed = false
override fun write(pcm: ShortArray, offset: Int, count: Int): Int {
check(!paused && !closed)
calls++
if (limit < 0) return limit
val accepted = minOf(limit, count)
for (i in offset until offset + accepted) samples.add(pcm[i])
return accepted
}
override fun pause() { paused = true }
override fun play() { paused = false }
override fun close() { closed = true }
}
private class Player(val device: Device = Device()) {
val input = ArrayDeque<ShortArray>()
val logs = ArrayList<String>()
val output = StreamAudioOutput({ device }, { logs.add(it) })
var finished = false
var pulls = 0
fun step(ms: Long, hold: Boolean = false) = output.step(ms * 1_000_000, hold,
{ pulls++; input.pollFirst() }, { finished && input.isEmpty() })
}
@Test fun slowStartupDoesNotBlockOtherPlayerWork() {
val p = Player(); p.input.add(ShortArray(960) { it.toShort() }); p.device.limit = 0
var videoSteps = 0
for (ms in 0L..300L step 5) { p.step(ms); videoSteps++ }
assertEquals(61, videoSteps); assertEquals(61, p.device.calls); assertEquals(1, p.pulls)
assertEquals(480, p.output.pendingFrames); assertEquals(0L, p.output.played)
p.device.limit = 960; p.step(305); p.device.head = 480; p.step(310)
assertTrue(p.output.drained); assertTrue(p.logs.any { it.contains("audio started") })
}
@Test fun partialWritesPreserveEverySampleAndOnlyPullOnce() {
val p = Player(); val pcm = ShortArray(960) { it.toShort() }; p.input.add(pcm)
p.device.limit = 120
repeat(8) { p.step(it * 5L) }
assertEquals(pcm.toList(), p.device.samples); assertEquals(1, p.pulls)
assertEquals(480L, p.output.written); assertEquals(0L, p.output.played)
assertEquals(0, p.output.pendingFrames); assertFalse(p.output.drained)
}
@Test fun waitingForInitialNetworkDataIsNotDeviceStall() {
val p = Player(Device(3848)); p.input.add(ShortArray(200)); p.step(0); p.step(10000)
assertEquals(100L, p.output.written); assertEquals(0L, p.output.played)
}
@Test fun clockDoesNotAdvanceWithWallTimeAndStalledDeviceFails() {
val p = Player(); p.input.add(ShortArray(960)); p.step(0); p.step(1999)
assertEquals(0L, p.output.played)
val error = assertThrows(IllegalStateException::class.java) { p.step(2000) }
assertTrue(error.message!!.contains("no playback progress"))
assertTrue(error.message!!.contains("written=480 played=0"))
}
@Test fun actualHeadProgressRestartsWatchdog() {
val p = Player(); p.input.add(ShortArray(960)); p.step(0)
p.device.head = 100; p.step(1900); p.step(3800)
assertEquals(100L, p.output.played)
p.device.head = 480; p.step(3900); p.step(10000)
assertTrue(p.output.drained)
}
@Test fun intentionalPausePreservesPartialPcmAndSuspendsWatchdog() {
val p = Player(); val pcm = ShortArray(960) { it.toShort() }; p.input.add(pcm); p.device.limit = 120
p.step(0); p.step(5, true); p.step(10000, true)
assertTrue(p.device.paused); assertEquals(1, p.device.calls); assertEquals(420, p.output.pendingFrames)
p.device.limit = 960; p.step(10005)
assertFalse(p.device.paused); assertEquals(pcm.toList(), p.device.samples)
}
@Test fun eofWaitsForPendingPcmAndPhysicalPlayback() {
val p = Player(); p.input.add(ShortArray(960) { 7 }); p.finished = true; p.device.limit = 480
p.step(0); p.device.head = 240; p.step(5)
assertFalse(p.output.drained); assertEquals(480L, p.output.written)
p.device.head = 480; p.step(10)
assertTrue(p.output.drained); assertEquals(List(960) { 7.toShort() }, p.device.samples)
}
@Test fun shortEofPrimesOldDeviceWithoutAdvancingMediaClock() {
val p = Player(Device(3848)); p.input.add(ShortArray(200) { 7 }); p.finished = true
repeat(12) { p.step(it * 5L) }
assertEquals(100L, p.output.written); assertEquals(0L, p.output.played)
assertEquals(200 + 3848 * 2, p.device.samples.size)
assertTrue(p.device.samples.drop(200).all { it == 0.toShort() })
p.device.head = 200; p.step(65)
assertEquals(100L, p.output.played); assertTrue(p.output.drained)
}
@Test fun eofAfterUnderrunAlsoPrimesOldDevice() {
val p = Player(Device(3848)); p.input.add(ShortArray(960)); p.step(0)
p.device.head = 480; p.step(5)
p.input.add(ShortArray(100) { 9 }); p.finished = true
repeat(12) { p.step(10 + it * 5L) }
assertEquals(530L, p.output.written)
assertTrue(p.device.samples.size / 2 - p.device.head >= p.device.threshold)
p.device.head = 530; p.step(75); assertTrue(p.output.drained)
}
@Test fun resetDiscardsPendingAndNewOutputStartsAtZero() {
val p = Player(); p.input.add(ShortArray(960) { 8 }); p.device.limit = 120; p.step(0); p.output.close()
assertTrue(p.device.closed); assertEquals(0, p.output.pendingFrames)
val next = Player(); next.input.add(ShortArray(960) { 9 }); next.step(10)
assertEquals(480L, next.output.written); assertEquals(0L, next.output.played)
assertTrue(next.device.samples.all { it == 9.toShort() })
}
@Test fun writeErrorContainsDeviceAndQueueState() {
val p = Player(); p.input.add(ShortArray(960)); p.device.limit = -6
val error = assertThrows(IllegalStateException::class.java) { p.step(0) }
assertTrue(error.message!!.contains("write=-6")); assertTrue(error.message!!.contains("pending=480"))
}
@Test fun unexpectedHeadResetIsNotInterpretedAsFourBillionPlayedFrames() {
val p = Player(); p.input.add(ShortArray(960)); p.step(0); p.device.head = 100; p.step(5)
p.device.head = 0
assertThrows(IllegalStateException::class.java) { p.step(10) }
}
}
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