Fail-fast camera mirroring on Android 11 and older

app/src/cli.c

@@ -189,7 +189,8 @@ static const struct sc_option options[] = {
         .longopt_id = OPT_VIDEO_SOURCE,
         .longopt = "video-source",
         .argdesc = "source",
-        .text = "Select the video source (display or camera).\n"
+        .text = "Select the video source (display or camera) to mirror.\n"
+                "Camera mirroring requires Android 12.\n"
                 "Default is display.",
     },
     {

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

@@ -1,7 +1,11 @@
 package com.genymobile.scrcpy;
 
+import com.genymobile.scrcpy.wrappers.ServiceManager;
+
 import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
+import android.content.ComponentName;
+import android.content.Intent;
 import android.media.AudioFormat;
 import android.media.AudioRecord;
 import android.media.AudioTimestamp;
@@ -60,7 +64,25 @@ private static AudioRecord createAudioRecord(int audioSource) {
         return builder.build();
     }
 
-    private void tryStartRecording(int attempts, int delayMs) throws CaptureForegroundException {
+    private static void startWorkaroundAndroid11() {
+        // Android 11 requires Apps to be at foreground to record audio.
+        // Normally, each App has its own user ID, so Android checks whether the requesting App has the user ID that's at the foreground.
+        // But scrcpy server is NOT an App, it's a Java application started from Android shell, so it has the same user ID (2000) with Android
+        // shell ("com.android.shell").
+        // If there is an Activity from Android shell running at foreground, then the permission system will believe scrcpy is also in the
+        // foreground.
+        Intent intent = new Intent(Intent.ACTION_MAIN);
+        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        intent.addCategory(Intent.CATEGORY_LAUNCHER);
+        intent.setComponent(new ComponentName(FakeContext.PACKAGE_NAME, "com.android.shell.HeapDumpActivity"));
+        ServiceManager.getActivityManager().startActivityAsUserWithFeature(intent);
+    }
+
+    private static void stopWorkaroundAndroid11() {
+        ServiceManager.getActivityManager().forceStopPackage(FakeContext.PACKAGE_NAME);
+    }
+
+    private void tryStartRecording(int attempts, int delayMs) throws AudioCaptureForegroundException {
         while (attempts-- > 0) {
             // Wait for activity to start
             SystemClock.sleep(delayMs);
@@ -72,7 +94,7 @@ private void tryStartRecording(int attempts, int delayMs) throws CaptureForegrou
                     Ln.e("Failed to start audio capture");
                     Ln.e("On Android 11, audio capture must be started in the foreground, make sure that the device is unlocked when starting "
                             + "scrcpy.");
-                    throw new CaptureForegroundException();
+                    throw new AudioCaptureForegroundException();
                 } else {
                     Ln.d("Failed to start audio capture, retrying...");
                 }
@@ -92,13 +114,13 @@ private void startRecording() {
         recorder.startRecording();
     }
 
-    public void start() throws CaptureForegroundException {
+    public void start() throws AudioCaptureForegroundException {
         if (Build.VERSION.SDK_INT == Build.VERSION_CODES.R) {
-            Workarounds.startForegroundWorkaround();
+            startWorkaroundAndroid11();
             try {
                 tryStartRecording(5, 100);
             } finally {
-                Workarounds.stopForegroundWorkaround();
+                stopWorkaroundAndroid11();
             }
         } else {
             startRecording();

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

@@ -0,0 +1,7 @@
+package com.genymobile.scrcpy;
+
+/**
+ * Exception thrown if audio capture failed on Android 11 specifically because the running App (shell) was not in foreground.
+ */
+public class AudioCaptureForegroundException extends Exception {
+}

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

@@ -125,7 +125,7 @@ public void start(TerminationListener listener) {
             } catch (ConfigurationException e) {
                 // Do not print stack trace, a user-friendly error-message has already been logged
                 fatalError = true;
-            } catch (CaptureForegroundException e) {
+            } catch (AudioCaptureForegroundException e) {
                 // Do not print stack trace, a user-friendly error-message has already been logged
             } catch (IOException e) {
                 Ln.e("Audio encoding error", e);
@@ -169,7 +169,7 @@ private synchronized void waitEnded() {
     }
 
     @TargetApi(Build.VERSION_CODES.M)
-    public void encode() throws IOException, ConfigurationException, CaptureForegroundException {
+    public void encode() throws IOException, ConfigurationException, AudioCaptureForegroundException {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) {
             Ln.w("Audio disabled: it is not supported before Android 11");
             streamer.writeDisableStream(false);

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

@@ -21,7 +21,7 @@ public AudioRawRecorder(AudioCapture capture, Streamer streamer) {
         this.streamer = streamer;
     }
 
-    private void record() throws IOException, CaptureForegroundException {
+    private void record() throws IOException, AudioCaptureForegroundException {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) {
             Ln.w("Audio disabled: it is not supported before Android 11");
             streamer.writeDisableStream(false);
@@ -60,7 +60,7 @@ public void start(TerminationListener listener) {
             boolean fatalError = false;
             try {
                 record();
-            } catch (CaptureForegroundException e) {
+            } catch (AudioCaptureForegroundException e) {
                 // Do not print stack trace, a user-friendly error-message has already been logged
             } catch (IOException e) {
                 Ln.e("Audio recording error", e);

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

@@ -1,6 +1,7 @@
 package com.genymobile.scrcpy;
 
 import android.annotation.SuppressLint;
+import android.annotation.TargetApi;
 import android.graphics.Rect;
 import android.hardware.camera2.CameraAccessException;
 import android.hardware.camera2.CameraCaptureSession;
@@ -13,7 +14,6 @@
 import android.os.Build;
 import android.os.Handler;
 import android.os.HandlerThread;
-import android.os.SystemClock;
 import android.view.Surface;
 
 import java.util.Arrays;
@@ -25,30 +25,30 @@
 
 public class CameraEncoder extends SurfaceEncoder {
 
-    private int maxSize;
-    private String cameraId;
-    private CameraPosition cameraPosition;
+    private final String cameraId;
+    private final CameraPosition cameraPosition;
 
+    private int maxSize;
     private String actualCameraId;
     private CameraDevice cameraDevice;
 
-    private HandlerThread cameraThread;
-    private Handler cameraHandler;
+    private final Handler cameraHandler;
 
     public CameraEncoder(int maxSize, String cameraId, CameraPosition cameraPosition, Streamer streamer,
-            int videoBitRate, int maxFps, List<CodecOption> codecOptions, String encoderName, boolean downsizeOnError) {
+                         int videoBitRate, int maxFps, List<CodecOption> codecOptions, String encoderName, boolean downsizeOnError) {
         super(streamer, videoBitRate, maxFps, codecOptions, encoderName, downsizeOnError);
 
         this.maxSize = maxSize;
         this.cameraId = cameraId;
         this.cameraPosition = cameraPosition;
 
-        cameraThread = new HandlerThread("camera");
+        HandlerThread cameraThread = new HandlerThread("camera");
         cameraThread.start();
         cameraHandler = new Handler(cameraThread.getLooper());
     }
 
     @SuppressLint("MissingPermission")
+    @TargetApi(Build.VERSION_CODES.N)
     private CameraDevice openCamera(String id)
             throws CameraAccessException, InterruptedException {
         Ln.v("Open Camera: " + id);
@@ -95,7 +95,7 @@ public void onError(CameraDevice camera, int error) {
         }
     }
 
-    @SuppressWarnings("deprecation")
+    @TargetApi(Build.VERSION_CODES.N)
     private CameraCaptureSession createCaptureSession(CameraDevice camera, Surface surface)
             throws CameraAccessException, InterruptedException {
         Ln.v("Create Capture Session");
@@ -121,6 +121,7 @@ public void onConfigureFailed(CameraCaptureSession session) {
         }
     }
 
+    @TargetApi(Build.VERSION_CODES.N)
     private void setRepeatingRequest(CameraCaptureSession session, CaptureRequest request)
             throws CameraAccessException, InterruptedException {
         Ln.v("Set Repeating Request");
@@ -129,13 +130,13 @@ private void setRepeatingRequest(CameraCaptureSession session, CaptureRequest re
         session.setRepeatingRequest(request, new CameraCaptureSession.CaptureCallback() {
             @Override
             public void onCaptureStarted(CameraCaptureSession session, CaptureRequest request,
-                    long timestamp, long frameNumber) {
+                                         long timestamp, long frameNumber) {
                 future.complete(null);
             }
 
             @Override
             public void onCaptureFailed(CameraCaptureSession session, CaptureRequest request,
-                    CaptureFailure failure) {
+                                        CaptureFailure failure) {
                 future.completeExceptionally(new CameraAccessException(CameraAccessException.CAMERA_ERROR));
             }
         }, cameraHandler);
@@ -148,7 +149,11 @@ public void onCaptureFailed(CameraCaptureSession session, CaptureRequest request
     }
 
     @Override
-    protected void initialize() {
+    protected void initialize() throws ConfigurationException {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.S) {
+            Ln.e("Camera mirroring is not support before Android 12");
+            throw new ConfigurationException("Camera mirroring is not supported");
+        }
     }
 
     @Override
@@ -219,9 +224,6 @@ protected void setSize(int size) {
 
     private void setSurfaceInternal(Surface surface) throws CameraAccessException {
         try {
-            // openCamera, createCaptureSession and setRepeatingRequest all
-            // requires foreground workaround on Android 11.
-            // getCameraIdList and getCameraCharacteristics don't need that.
             cameraDevice = openCamera(actualCameraId);
             CameraCaptureSession session = createCaptureSession(cameraDevice, surface);
             CaptureRequest.Builder requestBuilder = cameraDevice
@@ -236,41 +238,12 @@ private void setSurfaceInternal(Surface surface) throws CameraAccessException {
         }
     }
 
-    private void trySetSurface(int attempts, int delayMs, Surface surface) throws CaptureForegroundException {
-        while (attempts-- > 0) {
-            // Wait for activity to start
-            SystemClock.sleep(delayMs);
-            try {
-                setSurfaceInternal(surface);
-                return; // it worked
-            } catch (CameraAccessException e) {
-                if (attempts == 0) {
-                    Ln.e("Failed to start camera capture");
-                    Ln.e("On Android 11, camera capture must be started in the foreground, make sure that the device is unlocked when starting "
-                            + "scrcpy.");
-                    throw new CaptureForegroundException();
-                } else {
-                    Ln.d("Failed to start camera capture, retrying...");
-                }
-            }
-        }
-    }
-
     @Override
-    protected void setSurface(Surface surface) throws CaptureForegroundException {
-        if (Build.VERSION.SDK_INT == Build.VERSION_CODES.R) {
-            Workarounds.startForegroundWorkaround();
-            try {
-                trySetSurface(5, 100, surface);
-            } finally {
-                // Workarounds.stopForegroundWorkaround();
-            }
-        } else {
-            try {
-                setSurfaceInternal(surface);
-            } catch (CameraAccessException e) {
-                throw new RuntimeException(e);
-            }
+    protected void setSurface(Surface surface) {
+        try {
+            setSurfaceInternal(surface);
+        } catch (CameraAccessException e) {
+            throw new RuntimeException(e);
         }
     }
 

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

@@ -48,13 +48,13 @@ public SurfaceEncoder(Streamer streamer, int videoBitRate, int maxFps, List<Code
         this.downsizeOnError = downsizeOnError;
     }
 
-    protected abstract void initialize();
+    protected abstract void initialize() throws ConfigurationException;
 
-    protected abstract Size getSize() throws CaptureForegroundException, ConfigurationException;
+    protected abstract Size getSize() throws AudioCaptureForegroundException, ConfigurationException;
 
     protected abstract void setSize(int size);
 
-    protected abstract void setSurface(Surface surface) throws CaptureForegroundException;
+    protected abstract void setSurface(Surface surface) throws AudioCaptureForegroundException;
 
     protected abstract void dispose();
 
@@ -63,7 +63,7 @@ private boolean consumeResetCapture() {
     }
 
     protected void startStream()
-            throws CaptureForegroundException, IOException, ConfigurationException {
+            throws AudioCaptureForegroundException, IOException, ConfigurationException {
         initialize();
 
         Codec codec = streamer.getCodec();
@@ -260,7 +260,7 @@ public void start(TerminationListener listener) {
 
             try {
                 startStream();
-            } catch (ConfigurationException | CaptureForegroundException e) {
+            } catch (ConfigurationException | AudioCaptureForegroundException e) {
                 // Do not print stack trace, a user-friendly error-message has already been
                 // logged
             } catch (IOException e) {