diff --git a/tools/chatgui-android/app/src/debug/java/com/utun/chat/data/CallVideoHevcProbe.kt b/tools/chatgui-android/app/src/debug/java/com/utun/chat/data/CallVideoHevcProbe.kt
index 6e0b76ac..2e0d197c 100644
--- a/tools/chatgui-android/app/src/debug/java/com/utun/chat/data/CallVideoHevcProbe.kt
+++ b/tools/chatgui-android/app/src/debug/java/com/utun/chat/data/CallVideoHevcProbe.kt
@@ -45,10 +45,11 @@ object CallVideoHevcProbe {
             check(files.isNotEmpty()) { "No remote KEY files in $directory" }
             for (file in files) {
                 val bytes = file.readBytes(); val inspected = checkNotNull(CallVideoNative.inspect(2, bytes))
-                val format = CallVideoFormat(1, inspected[0].toInt(), inspected[1].toInt(), codec = 2,
+                val fps = Regex("-fps(30|50|60)-").find(file.name)?.groupValues?.get(1)?.toInt() ?: 30
+                val format = CallVideoFormat(1, inspected[0].toInt(), inspected[1].toInt(), fps = fps, codec = 2,
                     level = inspected[2].toInt(), profile = inspected[3].toInt())
                 val implementation = checkNotNull(decoders.modes.firstOrNull { it.supports(format) })
-                CallVideoCodec.verifyDecode(format, List(FRAMES) { CallVideoCodec.Packet(1_000_000L + it * 33333, true, bytes) },
+                CallVideoCodec.verifyDecode(format, List(FRAMES) { CallVideoCodec.Packet(1_000_000L + it * 1_000_000L / fps, true, bytes) },
                     implementation.name)
                 report("remote PASSED file=${file.name} format=$format decoder=${implementation.name}")
             }
@@ -63,7 +64,7 @@ object CallVideoHevcProbe {
             report("production encoders=$modes decoders=$receiving")
             for (mode in modes) for (portrait in listOf(false, true)) {
                 val format = CallVideoFormat(1, if (portrait) mode.size.height else mode.size.width,
-                    if (portrait) mode.size.width else mode.size.height, codec = 2, level = mode.level, profile = mode.profile)
+                    if (portrait) mode.size.width else mode.size.height, fps = mode.fps, codec = 2, level = mode.level, profile = mode.profile)
                 val implementation = checkNotNull(receiving.modes.firstOrNull { it.supports(format) })
                 CallVideoCodec(format, 1_000_000, mode.name).use { codec ->
                     codec.prepare()
@@ -74,13 +75,13 @@ object CallVideoHevcProbe {
                         val base = 2_000_000L + phase * 1_000_000L
                         val deadline = System.nanoTime() + 5_000_000_000L
                         while (packets.size < FRAMES && System.nanoTime() < deadline) {
-                            if (input < FRAMES && codec.submit(null, base + input * 33333, input == 0)) ++input
+                            if (input < FRAMES && codec.submit(null, base + input * 1_000_000L / format.fps, input == 0)) ++input
                             packets += codec.drain(); Thread.sleep(2)
                         }
                         check(packets.size == FRAMES && packets.first().key) { "Incomplete production encode" }
                         CallVideoCodec.verifyDecode(codec.format, packets, implementation.name)
                         report("production PASSED format=${codec.format} rate=$rate frames=${packets.size} decoder=${implementation.name}")
-                        File(directory, "production-${format.width}x${format.height}-$phase.key").writeBytes(packets.first().bytes)
+                        File(directory, "production-${format.width}x${format.height}-fps${format.fps}-$phase.key").writeBytes(packets.first().bytes)
                     }
                 }
             }
diff --git a/tools/chatgui-android/app/src/test/java/com/utun/chat/data/CallVideoCadenceTest.kt b/tools/chatgui-android/app/src/test/java/com/utun/chat/data/CallVideoCadenceTest.kt
new file mode 100644
index 00000000..b53cc9fc
--- /dev/null
+++ b/tools/chatgui-android/app/src/test/java/com/utun/chat/data/CallVideoCadenceTest.kt
@@ -0,0 +1,31 @@
+package com.utun.chat.data
+
+import org.junit.Assert.*
+import org.junit.Test
+
+class CallVideoCadenceTest {
+    @Test fun fasterCameraPreservesSelectedOutputRate() {
+        for (source in listOf(50, 60, 100, 330)) for (fps in listOf(30, 50, 60).filter { it <= source }) {
+            val cadence = CallVideoCadence(fps)
+            val accepted = (0 until source * 10).count { cadence.accept(1_000_000L + it * 1_000_000L / source) }
+            assertTrue("source=$source output=$fps accepted=$accepted", kotlin.math.abs(accepted - fps * 10) <= 1)
+        }
+    }
+    @Test fun jitterAndPauseDoNotCauseHalvingOrBurst() {
+        for (fps in listOf(30, 50, 60)) {
+            val cadence = CallVideoCadence(fps)
+            repeat(300) { assertTrue(cadence.accept(1_000_000L + it * 1_000_000L / fps + if (it % 2 == 0) 700 else -700)) }
+            assertTrue(cadence.accept(20_000_000)); assertFalse(cadence.accept(20_000_001))
+            assertFalse(cadence.accept(20_000_000)); assertFalse(cadence.accept(Long.MAX_VALUE))
+        }
+    }
+    @Test fun advertisedModesKeepSizeAndRateTogether() {
+        val low = CallVideoMode(1280, 720, 60); val high = CallVideoMode(1920, 1080, 30)
+        val state = CallVideoState(cameras = listOf(CallVideoCamera("c", "camera", listOf(low, high), 90, false)),
+            codecModes = mapOf(1 to listOf(high), 2 to listOf(low)))
+        assertEquals(listOf(low, high), state.modes("c", 0))
+        assertEquals(listOf(high), state.modes("c", 1))
+        assertEquals(listOf(low), state.modes("c", 2))
+        assertFalse(CallVideoMode(1920, 1080, 60) in state.modes("c", 0))
+    }
+}