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wz-phone/android/app/src/main/java/com/wzp/audio/AudioPipeline.kt
Siavash Sameni 00b405aa87
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feat: debug recording off by default, toggle in settings
- AudioPipeline.debugRecording defaults to false (was true)
- SettingsRepository: persist debug_recording preference
- CallViewModel: debugRecording StateFlow + setter, wired to AudioPipeline
- Only records PCM + RMS when explicitly enabled in settings

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-07 09:01:43 +04:00

360 lines
14 KiB
Kotlin

package com.wzp.audio
import android.Manifest
import android.content.Context
import android.content.pm.PackageManager
import android.media.AudioAttributes
import android.media.AudioFormat
import android.media.AudioRecord
import android.media.AudioTrack
import android.media.MediaRecorder
import android.media.audiofx.AcousticEchoCanceler
import android.media.audiofx.NoiseSuppressor
import android.util.Log
import androidx.core.content.ContextCompat
import com.wzp.engine.WzpEngine
import java.io.BufferedOutputStream
import java.io.File
import java.io.FileOutputStream
import java.io.OutputStreamWriter
import java.nio.ByteBuffer
import java.nio.ByteOrder
import java.util.concurrent.CountDownLatch
import java.util.concurrent.TimeUnit
import kotlin.math.pow
import kotlin.math.sqrt
/**
* Audio pipeline that captures mic audio and plays received audio using
* Android AudioRecord/AudioTrack APIs running on JVM threads.
*
* PCM samples are shuttled to/from the Rust engine via JNI ring buffers:
* - Capture: AudioRecord → WzpEngine.writeAudio() → Rust encoder → network
* - Playout: network → Rust decoder → WzpEngine.readAudio() → AudioTrack
*
* All audio is 48kHz, mono, 16-bit PCM (matching Opus codec requirements).
*/
class AudioPipeline(private val context: Context) {
companion object {
private const val TAG = "AudioPipeline"
private const val SAMPLE_RATE = 48000
private const val CHANNEL_IN = AudioFormat.CHANNEL_IN_MONO
private const val CHANNEL_OUT = AudioFormat.CHANNEL_OUT_MONO
private const val ENCODING = AudioFormat.ENCODING_PCM_16BIT
/** 20ms frame at 48kHz = 960 samples */
private const val FRAME_SAMPLES = 960
}
@Volatile
private var running = false
/** Playout (incoming voice) gain in dB. 0 = unity. */
@Volatile
var playoutGainDb: Float = 0f
/** Capture (mic) gain in dB. 0 = unity. */
@Volatile
var captureGainDb: Float = 0f
/** Whether to attach hardware AEC. Must be set before start(). */
var aecEnabled: Boolean = true
/** Enable debug recording of PCM + RMS histogram to cache dir. */
var debugRecording: Boolean = false
private var captureThread: Thread? = null
private var playoutThread: Thread? = null
// DirectByteBuffers for zero-copy JNI audio transfer.
// Allocated as class fields (NOT locals) because ART's JIT OSR
// can null local variables when it replaces the stack frame mid-loop.
// These survive OSR because they're on the heap.
private val captureDirectBuf: ByteBuffer =
ByteBuffer.allocateDirect(FRAME_SAMPLES * 2).order(ByteOrder.LITTLE_ENDIAN)
private val playoutDirectBuf: ByteBuffer =
ByteBuffer.allocateDirect(FRAME_SAMPLES * 2).order(ByteOrder.LITTLE_ENDIAN)
/** Latch counted down by each audio thread after exiting its loop.
* stop() does NOT wait on this — teardown waits via awaitDrain(). */
private var drainLatch: CountDownLatch? = null
private val debugDir: File by lazy {
File(context.cacheDir, "wzp_debug").also { it.mkdirs() }
}
fun start(engine: WzpEngine) {
if (running) return
running = true
drainLatch = CountDownLatch(2) // one for capture, one for playout
captureThread = Thread({
runCapture(engine)
drainLatch?.countDown() // signal: capture loop exited, no more JNI calls
// Park thread forever — exiting triggers a libcrypto TLS destructor
// crash (SIGSEGV in OPENSSL_free) on Android when a JNI-calling thread exits.
parkThread()
}, "wzp-capture").apply {
isDaemon = true
priority = Thread.MAX_PRIORITY
start()
}
playoutThread = Thread({
runPlayout(engine)
drainLatch?.countDown() // signal: playout loop exited
parkThread()
}, "wzp-playout").apply {
isDaemon = true
priority = Thread.MAX_PRIORITY
start()
}
Log.i(TAG, "audio pipeline started")
}
fun stop() {
running = false
// Don't join threads — they are parked as daemons to avoid native TLS crash.
// Don't null thread refs or drainLatch — teardown() needs awaitDrain().
Log.i(TAG, "audio pipeline stopped (running=false)")
}
/** Block until both audio threads have exited their loops (max 200ms).
* After this returns, no more JNI calls to the engine will be made. */
fun awaitDrain(): Boolean {
val ok = drainLatch?.await(200, TimeUnit.MILLISECONDS) ?: true
if (!ok) Log.w(TAG, "awaitDrain: audio threads did not drain in 200ms")
captureThread = null
playoutThread = null
drainLatch = null
return ok
}
private fun applyGain(pcm: ShortArray, count: Int, db: Float) {
if (db == 0f) return
val linear = 10f.pow(db / 20f)
for (i in 0 until count) {
pcm[i] = (pcm[i] * linear).toInt().coerceIn(-32000, 32000).toShort()
}
}
private fun computeRms(pcm: ShortArray, count: Int): Int {
var sumSq = 0.0
for (i in 0 until count) {
val s = pcm[i].toDouble()
sumSq += s * s
}
return sqrt(sumSq / count).toInt()
}
private fun parkThread() {
try {
Thread.sleep(Long.MAX_VALUE)
} catch (_: InterruptedException) {
// process exiting
}
}
private fun runCapture(engine: WzpEngine) {
if (ContextCompat.checkSelfPermission(context, Manifest.permission.RECORD_AUDIO)
!= PackageManager.PERMISSION_GRANTED
) {
Log.e(TAG, "RECORD_AUDIO permission not granted, capture disabled")
return
}
val minBuf = AudioRecord.getMinBufferSize(SAMPLE_RATE, CHANNEL_IN, ENCODING)
val bufSize = maxOf(minBuf, FRAME_SAMPLES * 2 * 4) // at least 4 frames
val recorder = try {
AudioRecord(
MediaRecorder.AudioSource.VOICE_COMMUNICATION,
SAMPLE_RATE,
CHANNEL_IN,
ENCODING,
bufSize
)
} catch (e: SecurityException) {
Log.e(TAG, "AudioRecord SecurityException: ${e.message}")
return
}
if (recorder.state != AudioRecord.STATE_INITIALIZED) {
Log.e(TAG, "AudioRecord failed to initialize")
recorder.release()
return
}
// Attach hardware AEC if available and enabled in settings
var aec: AcousticEchoCanceler? = null
var ns: NoiseSuppressor? = null
if (aecEnabled) {
if (AcousticEchoCanceler.isAvailable()) {
try {
aec = AcousticEchoCanceler.create(recorder.audioSessionId)
aec?.enabled = true
Log.i(TAG, "AEC enabled (session=${recorder.audioSessionId})")
} catch (e: Exception) {
Log.w(TAG, "AEC init failed: ${e.message}")
}
} else {
Log.w(TAG, "AEC not available on this device")
}
// Attach hardware noise suppressor if available
if (NoiseSuppressor.isAvailable()) {
try {
ns = NoiseSuppressor.create(recorder.audioSessionId)
ns?.enabled = true
Log.i(TAG, "NoiseSuppressor enabled")
} catch (e: Exception) {
Log.w(TAG, "NoiseSuppressor init failed: ${e.message}")
}
}
} else {
Log.i(TAG, "AEC disabled by user setting")
}
recorder.startRecording()
Log.i(TAG, "capture started: ${SAMPLE_RATE}Hz mono, buf=$bufSize, aec=${aec?.enabled}, ns=${ns?.enabled}")
val pcm = ShortArray(FRAME_SAMPLES)
// Debug: PCM file + RMS CSV
var pcmOut: BufferedOutputStream? = null
var rmsCsv: OutputStreamWriter? = null
val byteConv = ByteBuffer.allocate(FRAME_SAMPLES * 2).order(ByteOrder.LITTLE_ENDIAN)
var frameIdx = 0L
if (debugRecording) {
try {
pcmOut = BufferedOutputStream(FileOutputStream(File(debugDir, "capture.pcm")), 65536)
rmsCsv = OutputStreamWriter(FileOutputStream(File(debugDir, "capture_rms.csv")))
rmsCsv.write("frame,time_ms,rms\n")
} catch (e: Exception) {
Log.w(TAG, "debug recording init failed: ${e.message}")
}
}
try {
while (running) {
val read = recorder.read(pcm, 0, FRAME_SAMPLES)
if (read > 0) {
applyGain(pcm, read, captureGainDb)
// Zero-copy write via DirectByteBuffer (class field, survives JIT OSR)
captureDirectBuf.clear()
captureDirectBuf.asShortBuffer().put(pcm, 0, read)
engine.writeAudioDirect(captureDirectBuf, read)
// Debug: write raw PCM + RMS
if (pcmOut != null) {
byteConv.clear()
for (i in 0 until read) byteConv.putShort(pcm[i])
pcmOut.write(byteConv.array(), 0, read * 2)
}
if (rmsCsv != null) {
val rms = computeRms(pcm, read)
val timeMs = frameIdx * FRAME_SAMPLES * 1000L / SAMPLE_RATE
rmsCsv.write("$frameIdx,$timeMs,$rms\n")
}
frameIdx++
} else if (read < 0) {
Log.e(TAG, "AudioRecord.read error: $read")
break
}
}
} finally {
pcmOut?.close()
rmsCsv?.close()
recorder.stop()
aec?.release()
ns?.release()
recorder.release()
Log.i(TAG, "capture stopped (frames=$frameIdx)")
}
}
private fun runPlayout(engine: WzpEngine) {
val minBuf = AudioTrack.getMinBufferSize(SAMPLE_RATE, CHANNEL_OUT, ENCODING)
val bufSize = maxOf(minBuf, FRAME_SAMPLES * 2 * 4)
val track = AudioTrack.Builder()
.setAudioAttributes(
AudioAttributes.Builder()
.setUsage(AudioAttributes.USAGE_VOICE_COMMUNICATION)
.setContentType(AudioAttributes.CONTENT_TYPE_SPEECH)
.build()
)
.setAudioFormat(
AudioFormat.Builder()
.setSampleRate(SAMPLE_RATE)
.setChannelMask(CHANNEL_OUT)
.setEncoding(ENCODING)
.build()
)
.setBufferSizeInBytes(bufSize)
.setTransferMode(AudioTrack.MODE_STREAM)
.build()
if (track.state != AudioTrack.STATE_INITIALIZED) {
Log.e(TAG, "AudioTrack failed to initialize")
track.release()
return
}
track.play()
Log.i(TAG, "playout started: ${SAMPLE_RATE}Hz mono, buf=$bufSize")
val pcm = ShortArray(FRAME_SAMPLES)
val silence = ShortArray(FRAME_SAMPLES)
// Debug: PCM file + RMS CSV for playout
var pcmOut: BufferedOutputStream? = null
var rmsCsv: OutputStreamWriter? = null
val byteConv = ByteBuffer.allocate(FRAME_SAMPLES * 2).order(ByteOrder.LITTLE_ENDIAN)
var frameIdx = 0L
if (debugRecording) {
try {
pcmOut = BufferedOutputStream(FileOutputStream(File(debugDir, "playout.pcm")), 65536)
rmsCsv = OutputStreamWriter(FileOutputStream(File(debugDir, "playout_rms.csv")))
rmsCsv.write("frame,time_ms,rms\n")
} catch (e: Exception) {
Log.w(TAG, "debug playout recording init failed: ${e.message}")
}
}
try {
while (running) {
// Zero-copy read via DirectByteBuffer (class field, survives JIT OSR)
playoutDirectBuf.clear()
val read = engine.readAudioDirect(playoutDirectBuf, FRAME_SAMPLES)
if (read >= FRAME_SAMPLES) {
playoutDirectBuf.rewind()
playoutDirectBuf.asShortBuffer().get(pcm, 0, read)
applyGain(pcm, read, playoutGainDb)
track.write(pcm, 0, read)
// Debug: write raw PCM + RMS
if (pcmOut != null) {
byteConv.clear()
for (i in 0 until read) byteConv.putShort(pcm[i])
pcmOut.write(byteConv.array(), 0, read * 2)
}
if (rmsCsv != null) {
val rms = computeRms(pcm, read)
val timeMs = frameIdx * FRAME_SAMPLES * 1000L / SAMPLE_RATE
rmsCsv.write("$frameIdx,$timeMs,$rms\n")
}
frameIdx++
} else {
track.write(silence, 0, FRAME_SAMPLES)
// Log silence frames to RMS as 0
if (rmsCsv != null) {
val timeMs = frameIdx * FRAME_SAMPLES * 1000L / SAMPLE_RATE
rmsCsv.write("$frameIdx,$timeMs,0\n")
}
frameIdx++
Thread.sleep(5)
}
}
} finally {
pcmOut?.close()
rmsCsv?.close()
track.stop()
track.release()
Log.i(TAG, "playout stopped (frames=$frameIdx)")
}
}
}