Fallback Android video after explicit decoder rejection

tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallVideoEngine.kt

@@ -63,6 +63,8 @@ class CallVideoEngine(private val context: Context, private val id: Long) {
     private var reportAt = 0L
     private var encodedBytes = 0L
     private var encodedFrames = 0
+    private var rejectedGeneration = 0L
+    private var excluded = emptySet<Int>()
 
     init {
         handler.post {
@@ -96,7 +98,7 @@ class CallVideoEngine(private val context: Context, private val id: Long) {
 
     fun surface(surface: Surface?) = player.surface(surface)
     fun select(settings: CallVideoSettings) { handler.post {
-        if (!stopped) { wanted = settings; mutable.value = mutable.value.copy(settings = settings) }
+        if (!stopped) { wanted = settings; excluded = emptySet(); mutable.value = mutable.value.copy(settings = settings) }
     } }
     fun range(value: CallVideoBitrateRange) { handler.post {
         if (CallVideoNative.range(id, value.minimum * 1000, value.maximum * 1000)) mutable.value = mutable.value.copy(range = value)
@@ -119,11 +121,25 @@ class CallVideoEngine(private val context: Context, private val id: Long) {
             val s = CallVideoNative.status(id) ?: return
             if (s[6] >= 300000 && s[7] >= s[6]) mutable.value = mutable.value.copy(range = CallVideoBitrateRange((s[6] / 1000).toInt(), (s[7] / 1000).toInt()))
             if (keySerial != s[0]) { keySerial = s[0]; needKey = true }
+            val current = format
+            if (current != null && s[8] == current.generation && s[9] == 0L && rejectedGeneration != s[8]) {
+                rejectedGeneration = s[8]; excluded = excluded + current.codec
+                if (wanted.codec == 0) {
+                    report("Receiver rejected video; selecting fallback")
+                    val peer = CallVideoNative.peer(id)
+                    if (peer != null) change(peer)
+                } else fail("Receiver cannot decode selected codec")
+            }
             if (s[1] == format?.generation && s[2] > request) {
                 request = s[2]; pendingRequest = request; pendingRate = s[3].toInt()
             }
             if (!wanted.enabled) {
-                if (active != null) { closeCamera(); encoder?.close(); encoder = null; active = null; report("Video off") }
+                if (active != null) {
+                    val pending = if (confirmingRequest != 0L) confirmingRequest else pendingRequest
+                    if (pending != 0L) CallVideoNative.applied(id, format?.generation ?: 0, pending, 0)
+                    confirmingRequest = 0; pendingRequest = 0
+                    closeCamera(); encoder?.close(); encoder = null; active = null; report("Video off")
+                }
             } else if (wanted != active && !opening && !closing && (lastKey < 0 || System.nanoTime() / 1000 - lastKey >= 1_000_000)) {
                 val peer = CallVideoNative.peer(id)
                 if (peer != null) change(peer)
@@ -141,6 +157,7 @@ class CallVideoEngine(private val context: Context, private val id: Long) {
         val previousName = previous?.name; val previousRate = previous?.bitrate
         previous?.close(); encoder = null
         for (codec in if (wanted.codec == 0) listOf(2, 1) else listOf(wanted.codec)) {
+            if (codec in excluded) continue
             val implementation = encoders[codec] ?: continue
             val selected = CallVideoNative.choose(caps, peer, desired.copy(codec = codec).array()) ?: continue
             var candidate: CallVideoCodec? = null
@@ -160,7 +177,7 @@ class CallVideoEngine(private val context: Context, private val id: Long) {
                 LogManager.addLog("WARN", "call", "video mode rejected codec=$codec name=${implementation.name}: ${e.message}")
             }
         }
-        if (previousFormat != null && previousSettings != null && previousName != null && previousRate != null) {
+        if (previousFormat != null && previousFormat.codec !in excluded && previousSettings != null && previousName != null && previousRate != null) {
             encoder = CallVideoCodec(previousFormat, previousRate, previousName).also { it.prepare(); check(it.format == previousFormat) }
             wanted = previousSettings; needKey = true
             mutable.value = mutable.value.copy(settings = wanted)

tools/chatgui-android/app/src/main/java/com/utun/chat/data/CallVideoPlayer.kt

@@ -18,6 +18,7 @@ internal class CallVideoPlayer(private val id: Long, private val failure: (Strin
         var pending: ByteArray? = null; var meta = LongArray(12)
         var held = -1; var heldPts = -1L; var inflight = 0; var draining = false
         var sourceEpoch = 0L; var lastOutput = -1L; var lastProgress = System.nanoTime()
+        var reportedGeneration = 0L; var rejectedGeneration = 0L
         val clock = LongArray(8); val info = MediaCodec.BufferInfo()
         fun close() {
             try { decoder?.stop() } catch (e: Exception) { LogManager.addLog("WARN", "call", "video decoder stop: ${e.message}") }
@@ -47,6 +48,9 @@ internal class CallVideoPlayer(private val id: Long, private val failure: (Strin
                             } else if (info.size == 0) decoder!!.releaseOutputBuffer(out, false)
                             else {
                                 check(info.presentationTimeUs > lastOutput) { "Video decoder reordered PTS" }
+                                format?.let { f -> if (reportedGeneration != f.generation) {
+                                    CallVideoNative.decoded(id, f.generation, true); reportedGeneration = f.generation
+                                } }
                                 lastOutput = info.presentationTimeUs; inflight = (inflight - 1).coerceAtLeast(0)
                                 held = out; heldPts = info.presentationTimeUs; lastProgress = now
                             }
@@ -56,6 +60,7 @@ internal class CallVideoPlayer(private val id: Long, private val failure: (Strin
                     val data = pending
                     if (data != null && surface?.isValid == true && held < 0) {
                         val next = CallVideoFormat.from(meta)
+                        if (next.generation == rejectedGeneration) { pending = null; continue }
                         val key = meta[11] != 0L
                         if (format != next && decoder != null) {
                             if (!draining) {
@@ -89,7 +94,9 @@ internal class CallVideoPlayer(private val id: Long, private val failure: (Strin
                     if (decoder != null && held < 0 && inflight > 0 && now - lastProgress > 2_000_000_000) error("Video decoder stalled")
                 } catch (e: Exception) {
                     LogManager.addLog("ERROR", "call", "video receive call=$id: ${e.message}")
-                    close(); pending = null; CallVideoNative.requestKey(id); failure(e.message ?: "Video decoder failed")
+                    val generation = if (pending != null) meta[0] else format?.generation ?: 0
+                    if (generation != 0L) { CallVideoNative.decoded(id, generation, false); rejectedGeneration = generation }
+                    close(); pending = null; failure(e.message ?: "Video decoder failed")
                 }
                 Thread.sleep(5)
             }