audio: harden Opus playback

Preserve decoder timing and keep blocking speaker writes off codec
callbacks. Playback failures no longer take down video or control.

1 files changed, 21 insertions, 38 deletions

diff --git a/app/src/main/java/invalid/lena/scrcpy/AudioStream.java b/app/src/main/java/invalid/lena/scrcpy/AudioStream.java
index 13b39f5..45ea69c 100644
--- a/app/src/main/java/invalid/lena/scrcpy/AudioStream.java
+++ b/app/src/main/java/invalid/lena/scrcpy/AudioStream.java
@@ -2,7 +2,6 @@ package invalid.lena.scrcpy;
 
 import java.io.IOException;
 import java.io.InputStream;
-import java.util.concurrent.TimeUnit;
 
 // Reads the scrcpy audio socket and drives an AudioFrames sink.
 //
@@ -19,7 +18,10 @@ import java.util.concurrent.TimeUnit;
 // Takes a plain InputStream; caller owns stream lifecycle.
 public final class AudioStream {
 
-    private static final long FLAG_CONFIG = 1L << 62;
+    private static final long FLAG_SESSION  = 1L << 63;
+    private static final long FLAG_CONFIG   = 1L << 62;
+    private static final long FLAG_KEYFRAME = 1L << 61;
+    private static final long PTS_MASK      = ~(FLAG_SESSION | FLAG_CONFIG | FLAG_KEYFRAME);
 
     // Generous upper bound for one audio packet (a raw PCM block or an
     // opus packet is a few KB). A corrupt or hostile length field must
@@ -28,30 +30,12 @@ public final class AudioStream {
 
     private final InputStream  source;
     private final AudioFrames  sink;
-    private final Runnable     onFatalError;
     private Thread             thread;
     private volatile boolean   stop;
 
-    // Liveness signal for Session's stall watchdog. The audio socket is
-    // the only one that is reliably continuous: the server captures PCM
-    // at 48 kHz whether or not anything on the target's screen moves, so
-    // silence here means the wire is gone. Video is useless for this - a
-    // static screen queues nothing to the encoder and legitimately
-    // produces no frames for minutes.
-    private volatile boolean started;
-    private volatile long    lastPacketAtMs;
-
-    public boolean isStarted()      { return started; }
-    public long    lastPacketAtMs() { return lastPacketAtMs; }
-
     public AudioStream(InputStream source, AudioFrames sink) {
-        this(source, sink, null);
-    }
-
-    public AudioStream(InputStream source, AudioFrames sink, Runnable onFatalError) {
         this.source = source;
         this.sink = sink;
-        this.onFatalError = onFatalError;
     }
 
     public void start() {
@@ -85,9 +69,13 @@ public final class AudioStream {
                 throw new IOException("audio: unexpected codec " + Wire.fourccName(fourcc));
             }
             Log.i("audio meta codec=%s", Wire.fourccName(fourcc));
-            sink.start(fourcc);
-            lastPacketAtMs = monotonicMs();
-            started = true;
+            boolean playback = true;
+            try {
+                sink.start(fourcc);
+            } catch (RuntimeException e) {
+                Log.e(e, "audio output disabled");
+                playback = false;
+            }
 
             byte[] hdr = new byte[12];
             byte[] payload = new byte[16 * 1024];
@@ -97,33 +85,28 @@ public final class AudioStream {
                 long ptsAndFlags = Wire.readBe64(hdr, 0);
                 int  size = Wire.readBe32(hdr, 8);
                 boolean cfg = (ptsAndFlags & FLAG_CONFIG) != 0;
+                long ptsUs = ptsAndFlags & PTS_MASK;
                 if (size <= 0 || size > MAX_FRAME_SIZE) {
                     throw new IOException("audio frame size out of range: " + size);
                 }
                 if (size > payload.length) payload = new byte[size];
                 Wire.readFully(source, payload, 0, size);
-                lastPacketAtMs = monotonicMs();
-                sink.feed(payload, 0, size, cfg);
+                if (playback) {
+                    try {
+                        sink.feed(payload, 0, size, ptsUs, cfg);
+                    } catch (RuntimeException e) {
+                        Log.e(e, "audio output disabled");
+                        playback = false;
+                    }
+                }
                 if (++frames == 1) Log.i("audio frame n=1 size=%d cfg=%s", size, cfg);
             }
         } catch (IOException e) {
-            if (!stop) {
-                Log.e(e, "audio reader");
-                reportFatal();
-            }
+            if (!stop) Log.e(e, "audio reader");
         } catch (Exception e) {
             Log.e(e, "audio reader unexpected");
-            if (!stop) reportFatal();
         } finally {
             Log.i("audio reader: end");
         }
     }
-
-    private void reportFatal() {
-        if (onFatalError != null) onFatalError.run();
-    }
-
-    private static long monotonicMs() {
-        return TimeUnit.NANOSECONDS.toMillis(System.nanoTime());
-    }
 }