File size: 3,231 Bytes
38cf36c | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 | package com.blaze.agent.voice
import android.content.Context
import android.media.AudioFormat
import android.media.AudioRecord
import android.media.MediaRecorder
import android.util.Log
import com.blaze.agent.state.AppState
import com.blaze.agent.state.AppStateManager
import kotlinx.coroutines.*
import java.nio.ByteBuffer
import java.nio.ByteOrder
class WakeWordDetector(
private val context: Context,
private val onWakeWordDetected: () -> Unit
) {
companion object {
private const val TAG = "BlazeWakeWord"
private const val SAMPLE_RATE = 16000
private const val CHANNEL = AudioFormat.CHANNEL_IN_MONO
private const val ENCODING = AudioFormat.ENCODING_PCM_16BIT
private const val CHUNK_MS = 30
private const val CHUNK_SIZE = SAMPLE_RATE * CHUNK_MS / 1000 * 2
private const val ENERGY_THRESHOLD = 800.0f
private const val SPEECH_FRAMES_REQUIRED = 4
private val WAKE_PHRASES = listOf("hey blaze", "ok blaze", "blaze", "hi blaze")
}
private var audioRecord: AudioRecord? = null
private var detectorJob: Job? = null
private val scope = CoroutineScope(Dispatchers.Default + SupervisorJob())
private var consecutiveSpeechFrames = 0
private var isRunning = false
fun start() {
if (isRunning) return
isRunning = true
val minBuf = AudioRecord.getMinBufferSize(SAMPLE_RATE, CHANNEL, ENCODING)
val bufSize = maxOf(minBuf, CHUNK_SIZE * 4)
audioRecord = AudioRecord(MediaRecorder.AudioSource.VOICE_RECOGNITION, SAMPLE_RATE, CHANNEL, ENCODING, bufSize)
if (audioRecord?.state != AudioRecord.STATE_INITIALIZED) { Log.e(TAG, "AudioRecord init failed"); return }
audioRecord?.startRecording()
detectorJob = scope.launch {
val buffer = ByteArray(CHUNK_SIZE)
while (isRunning && isActive) {
val read = audioRecord?.read(buffer, 0, buffer.size) ?: break
if (read <= 0) continue
val energy = computeEnergy(buffer, read)
if (energy > ENERGY_THRESHOLD) {
consecutiveSpeechFrames++
if (consecutiveSpeechFrames >= SPEECH_FRAMES_REQUIRED) {
consecutiveSpeechFrames = 0
withContext(Dispatchers.Main) {
AppStateManager.transitionTo(AppState.LISTENING)
onWakeWordDetected()
}
stop()
}
} else { if (consecutiveSpeechFrames > 0) consecutiveSpeechFrames-- }
}
}
}
fun stop() {
isRunning = false; consecutiveSpeechFrames = 0
detectorJob?.cancel(); detectorJob = null
audioRecord?.stop(); audioRecord?.release(); audioRecord = null
}
private fun computeEnergy(buffer: ByteArray, length: Int): Float {
val shortBuf = ByteBuffer.wrap(buffer, 0, length).order(ByteOrder.LITTLE_ENDIAN).asShortBuffer()
var sum = 0.0; val count = length / 2
repeat(count) { val s = shortBuf.get().toDouble(); sum += s * s }
return if (count > 0) Math.sqrt(sum / count).toFloat() else 0f
}
}
|