diff --git a/tools/chatgui-android/app/src/debug/java/com/utun/chat/data/CallVideoProbe.kt b/tools/chatgui-android/app/src/debug/java/com/utun/chat/data/CallVideoProbe.kt
index fc5c4e56..65f7f570 100644
--- a/tools/chatgui-android/app/src/debug/java/com/utun/chat/data/CallVideoProbe.kt
+++ b/tools/chatgui-android/app/src/debug/java/com/utun/chat/data/CallVideoProbe.kt
@@ -10,7 +10,11 @@ import android.os.Bundle
 /** Запускается только явно через adb am instrument; камера и реальные звонки не затрагиваются. */
 class CallVideoProbe : Instrumentation() {
     private var remote: String? = null
-    override fun onCreate(arguments: Bundle?) { remote = arguments?.getString("remote"); super.onCreate(arguments); start() }
+    private var selectedCodec = 0
+    override fun onCreate(arguments: Bundle?) {
+        remote = arguments?.getString("remote"); selectedCodec = arguments?.getString("codec")?.toIntOrNull() ?: 0
+        super.onCreate(arguments); start()
+    }
     override fun onStart() {
         try {
             val decoders = CallVideoCodec.probeDecoders()
@@ -28,7 +32,9 @@ class CallVideoProbe : Instrumentation() {
             }
             val codecs = CallVideoCodec.probe()
             check(codecs.isNotEmpty() && decoders.isNotEmpty()) { "No verified encoders or decoders" }
+            check(selectedCodec == 0 || selectedCodec in codecs) { "Requested codec unavailable: $selectedCodec" }
             for ((codec, entry) in codecs) {
+                if (selectedCodec != 0 && selectedCodec != codec) continue
                 val f = CallVideoFormat(1, 640, 480, codec = codec, level = entry.level, profile = entry.profile)
                 verifyRateChanges(f, entry.name)
                 CallVideoCodec(f, 1_000_000, entry.name).use { encoder ->
@@ -80,7 +86,11 @@ class CallVideoProbe : Instrumentation() {
                                 "elapsed_ms=${(System.nanoTime() - started) / 1_000_000}"
                             android.util.Log.i("CallVideoProbe", "rate check $result")
                             check(input == 120 && output == 120 && key) { "Incomplete rate check: $result" }
-                            check(measured > rate / 2 && measured < rate.toLong() * 3 / 2) { "Bitrate change ineffective: $result" }
+                            // При сильной квантизации шум исчезает: low-rate кадр может занять меньше целевой полосы.
+                            // Игнорирование команды ловит верхний предел, возврат к 4M — нижний предел high-rate фаз.
+                            check(measured > 0 && measured < rate.toLong() * 3 / 2 && (rate == 300_000 || measured > rate / 2)) {
+                                "Bitrate change ineffective: $result"
+                            }
                         }
                     }
                 }