Retry on spurious error

MediaCodec may fail spuriously, typically when stopping an encoding and
starting a new one immediately (for example on device rotation).

In that case, retry (3 times), in many cases it should work.

Refs #3693 <https://github.com/Genymobile/scrcpy/issues/3693>

server/src/main/java/com/genymobile/scrcpy/ScreenEncoder.java

@@ -9,6 +9,7 @@ import android.media.MediaCodecList;
 import android.media.MediaFormat;
 import android.os.Build;
 import android.os.IBinder;
+import android.os.SystemClock;
 import android.view.Surface;
 
 import java.io.FileDescriptor;
@@ -27,6 +28,7 @@ public class ScreenEncoder implements Device.RotationListener {
 
     // Keep the values in descending order
     private static final int[] MAX_SIZE_FALLBACK = {2560, 1920, 1600, 1280, 1024, 800};
+    private static final int MAX_CONSECUTIVE_ERRORS = 3; // on error, retry MAX_CONSECUTIVE_ERRORS times
 
     private static final long PACKET_FLAG_CONFIG = 1L << 63;
     private static final long PACKET_FLAG_KEY_FRAME = 1L << 62;
@@ -43,6 +45,7 @@ public class ScreenEncoder implements Device.RotationListener {
     private long ptsOrigin;
 
     private boolean firstFrameSent;
+    private int consecutiveErrors;
 
     public ScreenEncoder(boolean sendFrameMeta, int bitRate, int maxFps, List<CodecOption> codecOptions, String encoderName,
             boolean downsizeOnError) {
@@ -108,20 +111,10 @@ public class ScreenEncoder implements Device.RotationListener {
                     codec.stop();
                 } catch (IllegalStateException | IllegalArgumentException e) {
                     Ln.e("Encoding error: " + e.getClass().getName() + ": " + e.getMessage());
-                    if (!downsizeOnError || firstFrameSent) {
-                        // Fail immediately
+                    if (!prepareRetry(device, screenInfo)) {
                         throw e;
                     }
-
-                    int newMaxSize = chooseMaxSizeFallback(screenInfo.getVideoSize());
-                    if (newMaxSize == 0) {
-                        // Definitively fail
-                        throw e;
-                    }
-
-                    // Retry with a smaller device size
-                    Ln.i("Retrying with -m" + newMaxSize + "...");
-                    device.setMaxSize(newMaxSize);
+                    Ln.i("Retrying...");
                     alive = true;
                 } finally {
                     codec.reset();
@@ -137,6 +130,39 @@ public class ScreenEncoder implements Device.RotationListener {
         }
     }
 
+    private boolean prepareRetry(Device device, ScreenInfo screenInfo) {
+        if (firstFrameSent) {
+            ++consecutiveErrors;
+            if (consecutiveErrors >= MAX_CONSECUTIVE_ERRORS) {
+                // Definitively fail
+                return false;
+            }
+
+            // Wait a bit to increase the probability that retrying will fix the problem
+            SystemClock.sleep(50);
+            return true;
+        }
+
+        if (!downsizeOnError) {
+            // Must fail immediately
+            return false;
+        }
+
+        // Downsizing on error is only enabled if an encoding failure occurs before the first frame (downsizing later could be surprising)
+
+        int newMaxSize = chooseMaxSizeFallback(screenInfo.getVideoSize());
+        Ln.i("newMaxSize = " + newMaxSize);
+        if (newMaxSize == 0) {
+            // Must definitively fail
+            return false;
+        }
+
+        // Retry with a smaller device size
+        Ln.i("Retrying with -m" + newMaxSize + "...");
+        device.setMaxSize(newMaxSize);
+        return true;
+    }
+
     private static int chooseMaxSizeFallback(Size failedSize) {
         int currentMaxSize = Math.max(failedSize.getWidth(), failedSize.getHeight());
         for (int value : MAX_SIZE_FALLBACK) {
@@ -172,6 +198,7 @@ public class ScreenEncoder implements Device.RotationListener {
                     if ((bufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) == 0) {
                         // If this is not a config packet, then it contains a frame
                         firstFrameSent = true;
+                        consecutiveErrors = 0;
                     }
                 }
             } finally {