Support adding and removing MediaRecorder to camera 2 session.

webrtc/sdk/android/src/java/org/webrtc/CameraCapturer.java

 /*
  *  Copyright 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 package org.webrtc;
 
 import android.content.Context;
+import android.media.MediaRecorder;
 import android.os.Handler;
 import android.os.Looper;
 import java.util.Arrays;
 
 @SuppressWarnings("deprecation")
 abstract class CameraCapturer implements CameraVideoCapturer {
   enum SwitchState {
     IDLE, // No switch requested.
     PENDING, // Waiting for previous capture session to open.
     IN_PROGRESS, // Waiting for new switched capture session to start.
   }
 
+  enum MediaRecorderState {
+    IDLE, // No media recording update (add or remove) requested.
+    IN_PROGRESS, // Waiting for new capture session with updated MediaRecorder surface to start.
+  }
+
   private static final String TAG = "CameraCapturer";
   private final static int MAX_OPEN_CAMERA_ATTEMPTS = 3;
   private final static int OPEN_CAMERA_DELAY_MS = 500;
   private final static int OPEN_CAMERA_TIMEOUT = 10000;
 
   private final CameraEnumerator cameraEnumerator;
   private final CameraEventsHandler eventsHandler;
   private final Handler uiThreadHandler;
 
   private final CameraSession.CreateSessionCallback createSessionCallback =
@@ skipping 13 matching lines @@
 
             if (switchState == SwitchState.IN_PROGRESS) {
               if (switchEventsHandler != null) {
                 switchEventsHandler.onCameraSwitchDone(cameraEnumerator.isFrontFacing(cameraName));
                 switchEventsHandler = null;
               }
               switchState = SwitchState.IDLE;
             } else if (switchState == SwitchState.PENDING) {
               switchState = SwitchState.IDLE;
               switchCameraInternal(switchEventsHandler);
+            } else if (mediaRecorderState == MediaRecorderState.IN_PROGRESS) {

[sakal, 2017/04/21 08:06:15]

One more thing, this shouldn't be else if. switchState can become PENDING while
mediaRecorderState is IN_PROGRESS.

[AlexG, 2017/04/21 19:38:11]

Done.

+              if (mediaRecorderEventsHandler != null) {
+                mediaRecorderEventsHandler.onMediaRecorderSuccess();
+                mediaRecorderEventsHandler = null;
+              }
+              mediaRecorder = null;

[sakal, 2017/04/21 08:06:15]

Why is mediaRecorder set to null here? This means cameraSwitch will cause the
mediaRecorder to be removed. Is this intended?

[AlexG, 2017/04/21 19:38:11]

Yes, camera switch is not allowed while MediaRecorder is added to camera
pipeline. I will add double check to disallow camera switch to start when media
recording is in progress.

+              mediaRecorderState = MediaRecorderState.IDLE;
             }
           }
         }
 
         @Override
         public void onFailure(CameraSession.FailureType failureType, String error) {
           checkIsOnCameraThread();
           uiThreadHandler.removeCallbacks(openCameraTimeoutRunnable);
           synchronized (stateLock) {
             capturerObserver.onCapturerStarted(false /* success */);
             openAttemptsRemaining--;
 
             if (openAttemptsRemaining <= 0) {
               Logging.w(TAG, "Opening camera failed, passing: " + error);
               sessionOpening = false;
               stateLock.notifyAll();
 
               if (switchState != SwitchState.IDLE) {
                 if (switchEventsHandler != null) {
                   switchEventsHandler.onCameraSwitchError(error);
                   switchEventsHandler = null;
                 }
                 switchState = SwitchState.IDLE;
               }
+              if (mediaRecorderState == MediaRecorderState.IN_PROGRESS) {
+                if (mediaRecorderEventsHandler != null) {
+                  mediaRecorderEventsHandler.onMediaRecorderError(error);
+                  mediaRecorderEventsHandler = null;
+                }
+                mediaRecorder = null;
+                mediaRecorderState = MediaRecorderState.IDLE;
+              }
 
               if (failureType == CameraSession.FailureType.DISCONNECTED) {
                 eventsHandler.onCameraDisconnected();
               } else {
                 eventsHandler.onCameraError(error);
               }
             } else {
               Logging.w(TAG, "Opening camera failed, retry: " + error);
 
               createSessionInternal(OPEN_CAMERA_DELAY_MS);
@@ skipping 98 matching lines @@
       eventsHandler.onCameraError("Camera failed to start within timeout.");
     }
   };
 
   // Initialized on initialize
   // -------------------------
   private Handler cameraThreadHandler;
   private Context applicationContext;
   private CapturerObserver capturerObserver;
   private SurfaceTextureHelper surfaceHelper;
+  private MediaRecorder mediaRecorder;
 
   private final Object stateLock = new Object();
   private boolean sessionOpening; /* guarded by stateLock */
   private CameraSession currentSession; /* guarded by stateLock */
   private String cameraName; /* guarded by stateLock */
   private int width; /* guarded by stateLock */
   private int height; /* guarded by stateLock */
   private int framerate; /* guarded by stateLock */
   private int openAttemptsRemaining; /* guarded by stateLock */
   private SwitchState switchState = SwitchState.IDLE; /* guarded by stateLock */
+  /* guarded by stateLock */
+  private MediaRecorderState mediaRecorderState = MediaRecorderState.IDLE;

[sakal, 2017/04/21 07:56:49]

Since these are only manipulated on the camera thread, I don't think a lock is
needed. Make a new section for variables only used on the camera thread.

[AlexG, 2017/04/21 19:38:11]

Done.

   private CameraSwitchHandler switchEventsHandler; /* guarded by stateLock */
+  private MediaRecorderHandler mediaRecorderEventsHandler; /* guarded by stateLock */
   // Valid from onDone call until stopCapture, otherwise null.
   private CameraStatistics cameraStatistics; /* guarded by stateLock */
   private boolean firstFrameObserved; /* guarded by stateLock */
 
   public CameraCapturer(
       String cameraName, CameraEventsHandler eventsHandler, CameraEnumerator cameraEnumerator) {
     if (eventsHandler == null) {
       eventsHandler = new CameraEventsHandler() {
         @Override
         public void onCameraError(String errorDescription) {}
@@ skipping 58 matching lines @@
       createSessionInternal(0);
     }
   }
 
   private void createSessionInternal(int delayMs) {
     uiThreadHandler.postDelayed(openCameraTimeoutRunnable, delayMs + OPEN_CAMERA_TIMEOUT);
     cameraThreadHandler.postDelayed(new Runnable() {
       @Override
       public void run() {
         createCameraSession(createSessionCallback, cameraSessionEventsHandler, applicationContext,
-            surfaceHelper, cameraName, width, height, framerate);
+            surfaceHelper, mediaRecorder, cameraName, width, height, framerate);
       }
     }, delayMs);
   }
 
   @Override
   public void stopCapture() {
     Logging.d(TAG, "Stop capture");
 
     synchronized (stateLock) {
       while (sessionOpening) {
@@ skipping 42 matching lines @@
     Logging.d(TAG, "switchCamera");
     cameraThreadHandler.post(new Runnable() {
       @Override
       public void run() {
         switchCameraInternal(switchEventsHandler);
       }
     });
   }
 
   @Override
+  public void addMediaRecorderToCamera(
+      final MediaRecorder mediaRecorder, final MediaRecorderHandler mediaRecoderEventsHandler) {
+    Logging.d(TAG, "addMediaRecorderToCamera");
+    cameraThreadHandler.post(new Runnable() {
+      @Override
+      public void run() {
+        updateMediaRecorderInternal(mediaRecorder, mediaRecoderEventsHandler);
+      }
+    });
+  }
+
+  @Override
+  public void removeMediaRecorderFromCamera(final MediaRecorderHandler mediaRecoderEventsHandler) {
+    Logging.d(TAG, "removeMediaRecorderFromCamera");
+    cameraThreadHandler.post(new Runnable() {
+      @Override
+      public void run() {
+        updateMediaRecorderInternal(null /* mediaRecorder */, mediaRecoderEventsHandler);
+      }
+    });
+  }
+
+  @Override
   public boolean isScreencast() {
     return false;
   }
 
   public void printStackTrace() {
     Thread cameraThread = null;
     if (cameraThreadHandler != null) {
       cameraThread = cameraThreadHandler.getLooper().getThread();
     }
     if (cameraThread != null) {
@@ skipping 30 matching lines @@
 
       if (!sessionOpening && currentSession == null) {
         Logging.d(TAG, "switchCamera: No session open");
         if (switchEventsHandler != null) {
           switchEventsHandler.onCameraSwitchError("Camera is not running.");
         }
         return;
       }
 
       this.switchEventsHandler = switchEventsHandler;
       if (sessionOpening) {

[magjed_webrtc, 2017/04/21 10:45:16]

We should decide if it's ok or not to call switchCamera in state
'mediaRecorderState == MediaRecorderState.IN_PROGRESS'. I don't think it's
working currently.

[AlexG, 2017/04/21 19:38:11]

I think this is not allowed - we can not reconfigure session while MediaRecorder
is added to it. I added a check to not allow camera switch to start if
MediaRecorder surface is added to camera pipeline.

         switchState = SwitchState.PENDING;
         return;
       } else {
         switchState = SwitchState.IN_PROGRESS;
       }
 
       Logging.d(TAG, "switchCamera: Stopping session");
       cameraStatistics.release();
       cameraStatistics = null;
       final CameraSession oldSession = currentSession;
       cameraThreadHandler.post(new Runnable() {
         @Override
         public void run() {
           oldSession.stop();
         }
       });
       currentSession = null;
 
       int cameraNameIndex = Arrays.asList(deviceNames).indexOf(cameraName);
       cameraName = deviceNames[(cameraNameIndex + 1) % deviceNames.length];
 
       sessionOpening = true;
       openAttemptsRemaining = 1;
       createSessionInternal(0);
     }
     Logging.d(TAG, "switchCamera done");
   }
 
+  private void reportUpdateMediaRecorderError(
+      String error, MediaRecorderHandler mediaRecoderEventsHandler) {
+    Logging.e(TAG, error);

[sakal, 2017/04/21 07:56:49]

Please add checkIsOnCameraThread()

[AlexG, 2017/04/21 19:38:11]

Done.

+    if (mediaRecoderEventsHandler != null) {
+      mediaRecoderEventsHandler.onMediaRecorderError(error);
+    }
+  }
+
+  private void updateMediaRecorderInternal(
+      final MediaRecorder mediaRecorder, final MediaRecorderHandler mediaRecoderEventsHandler) {
+    Logging.d(TAG,

[sakal, 2017/04/21 07:56:49]

Please add checkIsOnCameraThread()

[AlexG, 2017/04/21 19:38:11]

Done.

+        "updateMediaRecoderInternal internal. State: " + mediaRecorderState
+            + ". Session opening: " + sessionOpening);
+
+    synchronized (stateLock) {
+      if (mediaRecorderState != MediaRecorderState.IDLE) {
+        reportUpdateMediaRecorderError(
+            "MediaRecorder update already in progress.", mediaRecoderEventsHandler);
+        return;
+      }
+      if (switchState != SwitchState.IDLE) {
+        reportUpdateMediaRecorderError(
+            "MediaRecorder update while camera is switching.", mediaRecoderEventsHandler);
+        return;
+      }
+      if (sessionOpening) {
+        reportUpdateMediaRecorderError(
+            "MediaRecorder update while camera is still opening.", mediaRecoderEventsHandler);
+        return;
+      }
+
+      this.mediaRecorder = mediaRecorder;
+      this.mediaRecorderEventsHandler = mediaRecoderEventsHandler;
+      mediaRecorderState = MediaRecorderState.IN_PROGRESS;
+
+      Logging.d(TAG, "updateMediaRecoder: Stopping session");
+      cameraStatistics.release();
+      cameraStatistics = null;
+      final CameraSession oldSession = currentSession;
+      cameraThreadHandler.post(new Runnable() {
+        @Override
+        public void run() {
+          oldSession.stop();
+        }
+      });
+      currentSession = null;
+
+      sessionOpening = true;
+      openAttemptsRemaining = 1;
+      createSessionInternal(0);
+    }
+    Logging.d(TAG, "updateMediaRecoderInternal done");
+  }
+
   private void checkIsOnCameraThread() {
     if (Thread.currentThread() != cameraThreadHandler.getLooper().getThread()) {
       Logging.e(TAG, "Check is on camera thread failed.");
       throw new RuntimeException("Not on camera thread.");
     }
   }
 
   protected String getCameraName() {
     synchronized (stateLock) {
       return cameraName;
     }
   }
 
   abstract protected void createCameraSession(
       CameraSession.CreateSessionCallback createSessionCallback, CameraSession.Events events,
-      Context applicationContext, SurfaceTextureHelper surfaceTextureHelper, String cameraName,
-      int width, int height, int framerate);
+      Context applicationContext, SurfaceTextureHelper surfaceTextureHelper,
+      MediaRecorder mediaRecoder, String cameraName, int width, int height, int framerate);
 }