call: add SpeexDSP AEC (acoustic echo cancellation) for desktop + Android

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

@@ -6,8 +6,11 @@ import android.media.AudioDeviceInfo
 import android.media.AudioFormat
 import android.media.AudioManager
 import android.media.AudioRecord
+import android.media.AudioTimestamp
 import android.media.AudioTrack
 import android.media.MediaRecorder
+import android.os.Handler
+import android.os.Looper
 import com.utun.chat.ChatApplication
 
 /**
@@ -27,6 +30,11 @@ class CallAudioEngine {
         const val SAMPLE_RATE = 48000
         const val FRAME_MS = 20
         const val FRAME_SAMPLES = SAMPLE_RATE * FRAME_MS / 1000   // 960
+
+        /** Задержка рендер→захват AEC по умолчанию (кадров), если замер недоступен. */
+        const val AEC_DEFAULT_DELAY_FRAMES = 4
+        /** Акустический ход эха ~3мс (сэмплы @48кГц), добавляется к замеру. */
+        const val AEC_ACOUSTIC_SAMPLES = 150L
     }
 
     private var audioRecord: AudioRecord? = null
@@ -44,6 +52,12 @@ class CallAudioEngine {
 
     @Volatile private var muted = false
 
+    /* Для замера задержки AEC (getTimestamp) — счётчики кадров play/capture. */
+    @Volatile private var playFramesWritten = 0L
+    @Volatile private var capFramesRead = 0L
+    private val mainHandler = Handler(Looper.getMainLooper())
+    private val aecDelayRunnable = Runnable { measureAecDelay() }
+
     fun isActive(): Boolean = active
 
     /** Mute: пир слышит тишину (отправляем нулевые кадры вместо захваченного PCM). */
@@ -80,6 +94,12 @@ class CallAudioEngine {
 
         router.start()
 
+        /* AEC: включён только на громкой связи (спикерфон); на гарнитуре/разговорном
+         * динамике эхо незначимо. Задержка рендер→захват замеряется чуть позже. */
+        playFramesWritten = 0L
+        capFramesRead = 0L
+        syncAecForRoute(router.route)
+
         // ── AudioRecord (захват) ──
         val recMin = AudioRecord.getMinBufferSize(
             SAMPLE_RATE, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT)
@@ -134,6 +154,9 @@ class CallAudioEngine {
             priority = Thread.MAX_PRIORITY; start()
         }
 
+        /* Через ~300мс буферы устройства заполнены — замеряем реальную задержку AEC. */
+        mainHandler.postDelayed(aecDelayRunnable, 300)
+
         LogManager.addLog("INFO", "CallAudio", "started id=$id recBuf=$recMin trackBuf=$trackBuf")
         return true
     }
@@ -141,6 +164,7 @@ class CallAudioEngine {
     fun stop() {
         if (!active) return
         active = false
+        mainHandler.removeCallbacks(aecDelayRunnable)
 
         captureThread?.join(1000); captureThread = null
         playThread?.join(1000); playThread = null
@@ -172,6 +196,7 @@ class CallAudioEngine {
                 read += n
             }
             val out = if (muted) silence else buf
+            capFramesRead += FRAME_SAMPLES
             if (!NativeLib.callAudioFeed(callId, out)) {
                 LogManager.addLog("WARN", "CallAudio", "callAudioFeed returned false")
             }
@@ -182,21 +207,64 @@ class CallAudioEngine {
     private fun playLoop() {
         val buf = ShortArray(FRAME_SAMPLES)
         val silence = ShortArray(FRAME_SAMPLES)
+        val frameNs = FRAME_MS * 1_000_000L
+        var nextNs = System.nanoTime()
         while (active) {
-            val t0 = System.nanoTime()
             val track = audioTrack ?: return
             val n = NativeLib.callAudioPull(callId, buf)
             if (n > 0) track.write(buf, 0, n)
             if (n < FRAME_SAMPLES) track.write(silence, 0, FRAME_SAMPLES - n)
-            val elapsedMs = (System.nanoTime() - t0) / 1_000_000
-            val sleepMs = FRAME_MS - elapsedMs
-            if (sleepMs > 0) {
-                try { Thread.sleep(sleepMs) } catch (_: InterruptedException) { return }
+            playFramesWritten += FRAME_SAMPLES
+
+            /* абсолютный deadline: не даём Thread.sleep накопить систематический дрейф
+             * (важно для стабильного выравнивания рендер↔захват в AEC). */
+            nextNs += frameNs
+            val waitNs = nextNs - System.nanoTime()
+            if (waitNs > 0) {
+                try { Thread.sleep(waitNs / 1_000_000L, (waitNs % 1_000_000L).toInt()) }
+                catch (_: InterruptedException) { return }
+            } else {
+                nextNs = System.nanoTime()   /* отстали — сбрасываем, не копим долг */
             }
         }
         LogManager.addLog("DEBUG", "CallAudio", "play loop done")
     }
 
+    /** AEC включается только на громкой связи (спикерфон). */
+    fun syncAecForRoute(route: AudioRoute) {
+        val on = route == AudioRoute.SPEAKER
+        LogManager.addLog("INFO", "CallAudio", "AEC ${if (on) "on" else "off"} (route=$route)")
+        NativeLib.callAudioSetAec(on)
+    }
+
+    /** Замер реальной задержки рендер→захват и применение к AEC (один раз после старта). */
+    private fun measureAecDelay() {
+        if (!active) return
+        val track = audioTrack ?: return
+        val rec = audioRecord ?: return
+        try {
+            val tTs = AudioTimestamp()
+            val rTs = AudioTimestamp()
+            val trackOk = track.getTimestamp(tTs)
+            val recOk = rec.getTimestamp(rTs, AudioTimestamp.TIMEBASE_MONOTONIC) == AudioRecord.SUCCESS
+            if (!trackOk || !recOk) {
+                LogManager.addLog("WARN", "CallAudio", "getTimestamp unavailable; AEC delay = $AEC_DEFAULT_DELAY_FRAMES frames")
+                NativeLib.callAudioSetAecDelay(AEC_DEFAULT_DELAY_FRAMES)
+                return
+            }
+            val trackLatency = (playFramesWritten - tTs.framePosition).coerceAtLeast(0L)
+            val recLatency = (rTs.framePosition - capFramesRead).coerceAtLeast(0L)
+            val total = trackLatency + recLatency + AEC_ACOUSTIC_SAMPLES
+            val delayFrames = ((total + FRAME_SAMPLES - 1) / FRAME_SAMPLES).toInt().coerceIn(1, 20)
+            LogManager.addLog("INFO", "CallAudio",
+                "AEC delay measured: trackLat=$trackLatency recLat=$recLatency total=$total -> $delayFrames frames")
+            NativeLib.callAudioSetAecDelay(delayFrames)
+        } catch (e: Exception) {
+            LogManager.addLog("WARN", "CallAudio", "AEC delay measure failed: ${e.message}")
+            NativeLib.callAudioSetAecDelay(AEC_DEFAULT_DELAY_FRAMES)
+        }
+    }
+
     private fun restoreAudioMode() {
         try {
             val am = ChatApplication.instance.getSystemService(Context.AUDIO_SERVICE) as AudioManager

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

@@ -156,6 +156,10 @@ object NativeLib {
     fun callAudioPull(callId: Long, out: ShortArray): Int = nativeCallAudioPull(callId, out)
     fun callAudioStop() { nativeCallAudioStop() }
 
+    /* AEC (эхоподавление): включается по спикерфону; delay — измеренная задержка в кадрах. */
+    fun callAudioSetAec(enabled: Boolean) { nativeCallAudioSetAec(enabled) }
+    fun callAudioSetAecDelay(frames: Int) { nativeCallAudioSetAecDelay(frames) }
+
     /* ── Рация (PTT walkie-talkie) ── */
     fun radioSetActive(groupId: Long, on: Boolean) { nativeRadioSetActive(groupId, on) }
     fun radioSubscribers(groupId: Long): Int = nativeRadioSubscribers(groupId)
@@ -263,6 +267,8 @@ object NativeLib {
     private external fun nativeCallAudioFeed(callId: Long, samples: ShortArray): Boolean
     private external fun nativeCallAudioPull(callId: Long, out: ShortArray): Int
     private external fun nativeCallAudioStop()
+    private external fun nativeCallAudioSetAec(enabled: Boolean)
+    private external fun nativeCallAudioSetAecDelay(frames: Int)
 
     /* ── Рация JNI ── */
     private external fun nativeRadioSetActive(groupId: Long, on: Boolean)

tools/chatgui-android/app/src/main/java/com/utun/chat/viewmodel/ChatViewModel.kt

@@ -611,6 +611,7 @@ class ChatViewModel : ViewModel() {
                         callAudio.router.onChanged = { r, headset ->
                             _audioRoute.value = r
                             _headsetAvailable.value = headset
+                            callAudio.syncAecForRoute(r)
                         }
                         _audioRoute.value = callAudio.router.route
                         _headsetAvailable.value = callAudio.router.headsetAvailable