Test codec keyframes and bitrate selection across camera changes

tools/chatgui-android/app/src/test/java/com/utun/chat/data/StreamVideoCodecTest.kt

@@ -0,0 +1,32 @@
+package com.utun.chat.data
+
+import org.junit.Assert.*
+import org.junit.Test
+
+class StreamVideoCodecTest {
+    private fun nal(vararg bytes: Int) = byteArrayOf(0, 0, 0, 1) + bytes.map { it.toByte() }.toByteArray()
+    @Test fun everyCodecCarriesConfigurationWithKey() {
+        val configs = listOf(nal(0x67, 1) + nal(0x68, 2), nal(64, 1) + nal(66, 1) + nal(68, 1),
+            byteArrayOf(1, 2), byteArrayOf(3, 4), nal(0, 121) + nal(0, 129))
+        val frames = listOf(nal(0x65, 3), nal(38, 1), byteArrayOf(5, 6), byteArrayOf(7, 8), nal(0, 57))
+        StreamVideoCodec.values().forEachIndexed { i, codec ->
+            val packet = codec.keyFrame(frames[i], configs[i]); val decoded = codec.unpackKey(packet)
+            assertArrayEquals(configs[i], decoded.first); assertArrayEquals(frames[i], decoded.second)
+            assertEquals(codec, StreamVideoCodec.fromId(i + 1))
+        }
+    }
+    @Test fun malformedConfigurationIsRejected() {
+        for (size in 0..4) assertThrows(IllegalArgumentException::class.java) { StreamVideoCodec.VP9.unpackKey(ByteArray(size)) }
+        assertThrows(IllegalArgumentException::class.java) { StreamVideoCodec.AV1.unpackKey(byteArrayOf(0, 1, 0, 1, 1)) }
+        assertThrows(IllegalArgumentException::class.java) { StreamVideoCodec.H264.keyFrame(nal(0x41, 1), byteArrayOf()) }
+        val decoded = StreamVideoCodec.VP9.unpackKey(StreamVideoCodec.VP9.keyFrame(byteArrayOf(1), byteArrayOf()))
+        assertTrue(decoded.first.isEmpty()); assertArrayEquals(byteArrayOf(1), decoded.second)
+    }
+    @Test fun codecAndBitrateSurviveCameraModeSelection() {
+        val base = StreamCaptureMode("a", 1280, 720, 30, 30, false, "encoder", 2_000_000)
+        val hevc = base.copy(videoCodec = StreamVideoCodec.H265, minimumBitrate = 500000, maximumBitrate = 3000000)
+        assertEquals(hevc, StreamCameraModes.choose(listOf(base, hevc), hevc))
+        val config = StreamCaptureConfig(base, StreamOrientation.LEFT, 4000000).withMode(hevc)
+        assertEquals(3000000, config.bitrate); assertEquals(StreamOrientation.LEFT, config.orientation)
+    }
+}