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 8ee5b4c9..0c7a7fdc 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
@@ -5,10 +5,23 @@ import android.os.Bundle
 
 /** Запускается только явно через adb am instrument; камера и реальные звонки не затрагиваются. */
 class CallVideoProbe : Instrumentation() {
-    override fun onCreate(arguments: Bundle?) { super.onCreate(arguments); start() }
+    private var remote: String? = null
+    override fun onCreate(arguments: Bundle?) { remote = arguments?.getString("remote"); super.onCreate(arguments); start() }
     override fun onStart() {
         try {
             val decoders = CallVideoCodec.probeDecoders()
+            remote?.let { name ->
+                require(name.startsWith("call-video-") && '/' !in name)
+                val codec = if (name.endsWith("-codec1.idr")) 1 else 2
+                val bytes = java.io.File(targetContext.filesDir, name).readBytes()
+                val actual = checkNotNull(CallVideoNative.inspect(codec, bytes))
+                val format = CallVideoFormat(1, actual[0].toInt(), actual[1].toInt(), codec = codec,
+                    level = actual[2].toInt(), profile = actual[3].toInt())
+                val decoder = checkNotNull(decoders[codec])
+                CallVideoCodec.verifyDecode(format, List(4) { CallVideoCodec.Packet(1_000_000L + it * 33333, true, bytes) }, decoder.name)
+                finish(0, Bundle().apply { putString("remote_decoded", "$name using ${decoder.name} format=$format") })
+                return
+            }
             val codecs = CallVideoCodec.probe()
             check(codecs.isNotEmpty() && decoders.isNotEmpty()) { "No verified encoders or decoders" }
             for ((codec, entry) in codecs) {
@@ -16,6 +29,15 @@ class CallVideoProbe : Instrumentation() {
                 for (rate in listOf(4_000_000, 300_000, 4_000_000)) {
                     CallVideoCodec(f, rate, entry.name).use { it.prepare() }
                 }
+                CallVideoCodec(f, 1_000_000, entry.name).use { encoder ->
+                    encoder.prepare(); var key: ByteArray? = null; var input = 0
+                    val deadline = System.nanoTime() + 3_000_000_000
+                    while (key == null && System.nanoTime() < deadline) {
+                        if (input < 8 && encoder.submit(null, 10_000_000L + input * 33333, input == 0)) input++
+                        key = encoder.drain().firstOrNull { it.key }?.bytes; Thread.sleep(2)
+                    }
+                    java.io.File(targetContext.filesDir, "call-video-local-codec$codec.idr").writeBytes(checkNotNull(key))
+                }
             }
             finish(0, Bundle().apply { putString("codecs", codecs.toString()); putString("decoders", decoders.toString()) })
         } catch (e: Exception) {
diff --git a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallVideoCodec.kt b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallVideoCodec.kt
index a09299ab..e889bdf3 100644
--- a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallVideoCodec.kt
+++ b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallVideoCodec.kt
@@ -192,7 +192,7 @@ internal class CallVideoCodec(requested: CallVideoFormat, val bitrate: Int, val
             }
             return result
         }
-        private fun verifyDecode(f: CallVideoFormat, packets: List<Packet>, name: String) {
+        internal fun verifyDecode(f: CallVideoFormat, packets: List<Packet>, name: String) {
             val type = StreamVideoCodec.fromId(f.codec)
             val config = type.unpackKey(packets.first().bytes).first
             val decoder = MediaCodec.createByCodecName(name)