feat(dave): improve DAVE decryption handling and silence frame processing

Author: alexandre433

src/Discord/Voice/Client/Packet.php

@@ -229,7 +229,9 @@ public function decrypt(?string $message = null): string|false|null
                 $resultMessage = substr($stripped, $baseHeaderSize);
             }
 
-            if ($resultMessage !== false && is_callable($this->inboundFrameDecryptor)) {
+            // Skip DAVE decryption for the standard Opus silence frame — it is never DAVE-encrypted
+            // and passing it to libdave generates noisy "Decrypt skipping silence" C++ log spam.
+            if ($resultMessage !== false && $resultMessage !== "\xF8\xFF\xFE" && is_callable($this->inboundFrameDecryptor)) {
                 $resultMessage = ($this->inboundFrameDecryptor)($resultMessage, $this);
             }
 

src/Discord/Voice/Dave/MediaCryptoService.php

@@ -116,7 +116,15 @@ public function decrypt(string $frame, ?string $userId, ?int $ssrc = null): stri
         }
 
         if ($decrypted === false) {
-            return false;
+            // Frame failed DAVE decryption — most likely not DAVE-encrypted yet
+            // (user's client hasn't completed MLS handshake). Pass the frame through
+            // as plain Opus so audio isn't silently dropped during key transitions.
+            $this->logger->debug('DAVE decrypt returned auth failure; passing frame through as plain Opus.', [
+                'protocol_version' => $protocolVersion,
+                'frame_length' => strlen($frame),
+                'ssrc' => $ssrc,
+            ]);
+            return $frame;
         }
 
         if ($decrypted === null) {

src/Discord/Voice/Processes/Ffmpeg.php

@@ -74,6 +74,7 @@ public static function encode(
     ): Process {
         $flags = [
             '-protocol_whitelist', 'file,http,https,tcp,tls,crypto,pipe',
+            '-fflags', '+nobuffer',
             '-i', escapeshellarg($filename ?? 'pipe:0'),
             '-map_metadata', '-1',
             '-f', 'opus',

src/Discord/Voice/VoiceClient.php

@@ -712,17 +712,21 @@ protected function readOggOpus(Deferred $deferred, OggStream &$ogg, int &$loops)
     {
         $this->readOpusTimer = null;
 
-        $loops += 1;
+        // Record the target send time for THIS packet BEFORE the async fetch so
+        // that the 20 ms window runs concurrently with getPacket(), not after it.
+        $targetTime = $this->startTime + (20.0 / 1000.0) * $loops;
+        $loops++;
 
-        // If the client is paused, delay by frame size and check again.
+        // If the client is paused, insert silence and wait until the next slot.
         if ($this->paused) {
             $this->udp->insertSilence();
-            $this->readOpusTimer = $this->discord->getLoop()->addTimer($this->frameSize / 1000, fn () => $this->readOggOpus($deferred, $ogg, $loops));
+            $delay = max(0.0, $targetTime + (20.0 / 1000.0) - microtime(true));
+            $this->readOpusTimer = $this->discord->getLoop()->addTimer($delay, fn () => $this->readOggOpus($deferred, $ogg, $loops));
 
             return;
         }
 
-        $ogg->getPacket()->then(function ($packet) use (&$loops, &$ogg, $deferred) {
+        $ogg->getPacket()->then(function ($packet) use (&$loops, &$ogg, $deferred, $targetTime) {
             // EOF for Ogg stream.
             if (null === $packet) {
                 $this->reset();
@@ -731,12 +735,14 @@ protected function readOggOpus(Deferred $deferred, OggStream &$ogg, int &$loops)
                 return;
             }
 
-            $this->udp->sendBuffer($packet);
-
-            $nextTime = $this->startTime + (20.0 / 1000.0) * $loops;
-            $delay = max(0.0, $nextTime - microtime(true));
+            $delay = max(0.0, $targetTime - microtime(true));
 
-            $this->readOpusTimer = $this->discord->getLoop()->addTimer($delay, fn () => $this->readOggOpus($deferred, $ogg, $loops));
+            // Use addTimer(0) even when the deadline has already passed to avoid
+            // unbounded recursion if several consecutive packets arrive late.
+            $this->readOpusTimer = $this->discord->getLoop()->addTimer($delay, function () use ($packet, $deferred, &$ogg, &$loops) {
+                $this->udp->sendBuffer($packet);
+                $this->readOggOpus($deferred, $ogg, $loops);
+            });
         }, function () use ($deferred) {
             $this->reset();
             $deferred->resolve(null);