diff --git a/tools/chatgui-android/video-tests/src/main/kotlin/android/media/HostStreamAudio.kt b/tools/chatgui-android/video-tests/src/main/kotlin/android/media/HostStreamAudio.kt
new file mode 100644
index 00000000..b95bc064
--- /dev/null
+++ b/tools/chatgui-android/video-tests/src/main/kotlin/android/media/HostStreamAudio.kt
@@ -0,0 +1,59 @@
+package android.media
+
+import java.util.concurrent.CopyOnWriteArrayList
+
+class AudioAttributes {
+    companion object { const val USAGE_MEDIA = 1; const val CONTENT_TYPE_MOVIE = 1 }
+    class Builder {
+        fun setUsage(value: Int) = this
+        fun setContentType(value: Int) = this
+        fun build() = AudioAttributes()
+    }
+}
+class AudioFormat {
+    companion object { const val CHANNEL_OUT_STEREO = 12; const val ENCODING_PCM_16BIT = 2 }
+    class Builder {
+        fun setSampleRate(value: Int) = this
+        fun setChannelMask(value: Int) = this
+        fun setEncoding(value: Int) = this
+        fun build() = AudioFormat()
+    }
+}
+/** Только JVM: SDK output остаётся наблюдаемым до подтверждённого release. */
+class AudioTrack {
+    companion object {
+        const val STATE_INITIALIZED = 1; const val MODE_STREAM = 1; const val WRITE_NON_BLOCKING = 1
+        val created = CopyOnWriteArrayList<AudioTrack>()
+        var nextFailures = emptySet<String>()
+        fun getMinBufferSize(rate: Int, channels: Int, encoding: Int) = 3840
+    }
+    class Builder {
+        fun setAudioAttributes(value: AudioAttributes) = this
+        fun setAudioFormat(value: AudioFormat) = this
+        fun setBufferSizeInBytes(value: Int) = this
+        fun setTransferMode(value: Int) = this
+        fun build() = AudioTrack().also { created.add(it) }
+    }
+    var failures = nextFailures
+    var released = false
+        private set
+    val state get() = STATE_INITIALIZED
+    var playState = 0
+        private set
+    val bufferSizeInFrames = 960
+    var startThresholdInFrames = 1
+        private set
+    var playbackHeadPosition = 0
+        private set
+    val underrunCount = 0
+    fun setStartThresholdInFrames(value: Int) { check("threshold" !in failures); startThresholdInFrames = value }
+    fun write(pcm: ShortArray, offset: Int, count: Int, mode: Int): Int {
+        check(!released); check("write" !in failures); playbackHeadPosition += count / 2; return count
+    }
+    fun pause() { check(!released); playState = 0 }
+    fun play() { check(!released); check("play" !in failures); playState = 1 }
+    fun release() {
+        check("release" !in failures) { "audio release failed" }; released = true
+        check("release after" !in failures) { "audio release failed after effect" }
+    }
+}
diff --git a/tools/chatgui-android/video-tests/src/main/kotlin/android/os/HostVideoOs.kt b/tools/chatgui-android/video-tests/src/main/kotlin/android/os/HostVideoOs.kt
index c30b323b..5e9a4da1 100644
--- a/tools/chatgui-android/video-tests/src/main/kotlin/android/os/HostVideoOs.kt
+++ b/tools/chatgui-android/video-tests/src/main/kotlin/android/os/HostVideoOs.kt
@@ -63,3 +63,4 @@ object SystemClock {
     fun elapsedRealtimeNanos(): Long = System.nanoTime()
 }
 object Build { object VERSION { const val SDK_INT = 36 } }
+object Process { const val THREAD_PRIORITY_AUDIO = -16; fun setThreadPriority(value: Int) {} }
diff --git a/tools/chatgui-android/video-tests/src/main/kotlin/com/utun/chat/data/StreamHost.kt b/tools/chatgui-android/video-tests/src/main/kotlin/com/utun/chat/data/StreamHost.kt
new file mode 100644
index 00000000..9ac85446
--- /dev/null
+++ b/tools/chatgui-android/video-tests/src/main/kotlin/com/utun/chat/data/StreamHost.kt
@@ -0,0 +1,47 @@
+package com.utun.chat.data
+
+import android.media.AudioTrack
+import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.ConcurrentLinkedQueue
+import java.util.concurrent.atomic.AtomicLong
+import kotlinx.coroutines.flow.MutableStateFlow
+
+object CallController { var blocked = false; fun blocksMedia() = blocked }
+object StreamController { private val ids = AtomicLong(100); fun nextId() = ids.incrementAndGet() }
+object MediaAudioController {
+    data class State(val switching: Boolean = false)
+    val state = MutableStateFlow(State())
+    var failures = emptySet<String>()
+    val outputs = ConcurrentHashMap.newKeySet<AudioTrack>()
+    fun attachOutput(track: AudioTrack): AutoCloseable {
+        check("attach" !in failures); outputs.add(track)
+        return AutoCloseable { check("detach" !in failures); outputs.remove(track) }
+    }
+}
+
+/** Native-границы viewer/mixer: fault injection до изменения владельца, никаких JNI/DSP/сети. */
+object HostStreams {
+    val ports = ConcurrentHashMap.newKeySet<Long>()
+    val signals = ConcurrentHashMap.newKeySet<Long>()
+    val playbacks = ConcurrentHashMap.newKeySet<Long>()
+    val records = ConcurrentLinkedQueue<ByteArray>()
+    private val sequence = AtomicLong()
+    @Volatile var failures = emptySet<String>()
+    @Volatile var audioEnabled = false
+    @Volatile var status = false
+    @Volatile var onWait: () -> Unit = {}
+    @Volatile var onPull: () -> Unit = {}
+    fun access(name: String) { check(name !in failures) { "stream $name failed" } }
+    fun open(id: Long): Boolean { access("open"); ports.add(id); return true }
+    fun stop(id: Long) { access("stop"); ports.remove(id) }
+    fun createSignal(): Long { access("signal create"); return sequence.incrementAndGet().also { signals.add(it) } }
+    fun closeSignal(handle: Long) { access("signal close"); check(signals.remove(handle)) }
+    fun notifySignal(handle: Long) { access("signal notify"); check(handle in signals) }
+    fun waitSignal(handle: Long): Int { onWait(); access("signal wait"); check(handle in signals); Thread.sleep(2); return 0 }
+    fun createPlayback(): Long { access("playback create"); return sequence.incrementAndGet().also { playbacks.add(it) } }
+    fun closePlayback(handle: Long) { access("playback close"); check(playbacks.remove(handle)) }
+    fun reset() {
+        ports.clear(); signals.clear(); playbacks.clear(); records.clear(); failures = emptySet()
+        audioEnabled = false; status = false; onWait = {}; onPull = {}
+    }
+}