Reland of Support adding and removing MediaRecorder to camera 2 session. (patchset #1 id:1 of https://codereview.webrtc.org/2844233002/ )

Reason for revert:
Revert "Revert of Support adding and removing MediaRecorder to camera 2 session. (patchset #5 id:80001 of https://codereview.webrtc.org/2833773003/ )"

Will fix external bots by cherry picking this CL and updating external functions which depend on CameraVideoCapturer interface

Original issue's description:
> Revert of Support adding and removing MediaRecorder to camera 2 session. (patchset #5 id:80001 of https://codereview.webrtc.org/2833773003/ )
>
> Reason for revert:
> Breaks external bot
>
> Original issue's description:
> > Support adding and removing MediaRecorder to camera 2 session.
> >
> > Camera 1 API is not supported.
> >
> > BUG=b/36684011
> >
> > Review-Url: https://codereview.webrtc.org/2833773003
> > Cr-Commit-Position: refs/heads/master@{#17901}
> > Committed: 2fc04769fa
>
> TBR=sakal@webrtc.org,glaznev@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=b/36684011
>
> Review-Url: https://codereview.webrtc.org/2844233002
> Cr-Commit-Position: refs/heads/master@{#17905}
> Committed: 6702739862

TBR=sakal@webrtc.org,magjed@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=b/36684011

Review-Url: https://codereview.webrtc.org/2844393002
Cr-Commit-Position: refs/heads/master@{#17915}

webrtc/sdk/android/api/org/webrtc/Camera1Capturer.java

@@ -10,11 +10,8 @@
 
 package org.webrtc;
 
-import org.webrtc.CameraEnumerationAndroid.CaptureFormat;
-
 import android.content.Context;
-
+import android.media.MediaRecorder;
-import java.util.List;
 
 public class Camera1Capturer extends CameraCapturer {
   private final boolean captureToTexture;
@@ -29,8 +26,11 @@ public class Camera1Capturer extends CameraCapturer {
   @Override
   protected void createCameraSession(CameraSession.CreateSessionCallback createSessionCallback,
       CameraSession.Events events, Context applicationContext,
-      SurfaceTextureHelper surfaceTextureHelper, String cameraName, int width, int height,
+      SurfaceTextureHelper surfaceTextureHelper, MediaRecorder mediaRecorder, String cameraName,
-      int framerate) {
+      int width, int height, int framerate) {
+    if (mediaRecorder != null) {
+      throw new RuntimeException("MediaRecoder is not supported for camera 1.");
+    }
     Camera1Session.create(createSessionCallback, events, captureToTexture, applicationContext,
         surfaceTextureHelper, Camera1Enumerator.getCameraIndex(cameraName), width, height,
         framerate);

webrtc/sdk/android/api/org/webrtc/Camera2Capturer.java

@@ -13,6 +13,7 @@ package org.webrtc;
 import android.annotation.TargetApi;
 import android.content.Context;
 import android.hardware.camera2.CameraManager;
+import android.media.MediaRecorder;
 
 @TargetApi(21)
 public class Camera2Capturer extends CameraCapturer {
@@ -29,9 +30,9 @@ public class Camera2Capturer extends CameraCapturer {
   @Override
   protected void createCameraSession(CameraSession.CreateSessionCallback createSessionCallback,
       CameraSession.Events events, Context applicationContext,
-      SurfaceTextureHelper surfaceTextureHelper, String cameraName, int width, int height,
+      SurfaceTextureHelper surfaceTextureHelper, MediaRecorder mediaRecoder, String cameraName,
-      int framerate) {
+      int width, int height, int framerate) {
     Camera2Session.create(createSessionCallback, events, applicationContext, cameraManager,
-        surfaceTextureHelper, cameraName, width, height, framerate);
+        surfaceTextureHelper, mediaRecoder, cameraName, width, height, framerate);
   }
 }

webrtc/sdk/android/api/org/webrtc/CameraVideoCapturer.java

@@ -10,6 +10,8 @@
 
 package org.webrtc;
 
+import android.media.MediaRecorder;
+
 /**
  * Base interface for camera1 and camera2 implementations. Extends VideoCapturer with a
  * switchCamera() function. Also provides subinterfaces for handling camera events, and a helper
@@ -59,6 +61,32 @@ public interface CameraVideoCapturer extends VideoCapturer {
    */
   void switchCamera(CameraSwitchHandler switchEventsHandler);
 
+  /**
+   * MediaRecorder add/remove handler - one of these functions are invoked with the result of
+   * addMediaRecorderToCamera() or removeMediaRecorderFromCamera calls.
+   * The callback may be called on an arbitrary thread.
+   */
+  public interface MediaRecorderHandler {
+    // Invoked on success.
+    void onMediaRecorderSuccess();
+
+    // Invoked on failure, e.g. camera is stopped or any exception happens.
+    void onMediaRecorderError(String errorDescription);
+  }
+
+  /**
+   * Add MediaRecorder to camera pipeline. This can only be called while the camera is running.
+   * Once MediaRecorder is added to camera pipeline camera switch is not allowed.
+   * This function can be called from any thread.
+   */
+  void addMediaRecorderToCamera(MediaRecorder mediaRecorder, MediaRecorderHandler resultHandler);
+
+  /**
+   * Remove MediaRecorder from camera pipeline. This can only be called while the camera is running.
+   * This function can be called from any thread.
+   */
+  void removeMediaRecorderFromCamera(MediaRecorderHandler resultHandler);
+
   /**
    * Helper class to log framerate and detect if the camera freezes. It will run periodic callbacks
    * on the SurfaceTextureHelper thread passed in the ctor, and should only be operated from that

webrtc/sdk/android/instrumentationtests/src/org/webrtc/Camera2CapturerTest.java

@@ -25,6 +25,7 @@ import android.support.test.InstrumentationRegistry;
 import android.support.test.filters.LargeTest;
 import android.support.test.filters.MediumTest;
 import android.support.test.filters.SmallTest;
+import java.io.IOException;
 import java.util.concurrent.CountDownLatch;
 import org.chromium.base.test.BaseJUnit4ClassRunner;
 import org.junit.After;
@@ -244,6 +245,12 @@ public class Camera2CapturerTest {
     fixtures.cameraEventsInvoked();
   }
 
+  @Test
+  @MediumTest
+  public void testUpdateMediaRecorder() throws InterruptedException, IOException {
+    fixtures.updateMediaRecorder(true /* useSurfaceCapture */);
+  }
+
   // Test what happens when attempting to call e.g. switchCamera() after camera has been stopped.
   @Test
   @MediumTest

webrtc/sdk/android/instrumentationtests/src/org/webrtc/CameraVideoCapturerTestFixtures.java

@@ -15,7 +15,13 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import android.annotation.TargetApi;
 import android.content.Context;
+import android.media.CamcorderProfile;
+import android.media.MediaRecorder;
+import android.os.Environment;
+import java.io.File;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
@@ -502,6 +508,95 @@ class CameraVideoCapturerTestFixtures {
     disposeVideoTrackWithRenderer(videoTrackWithRenderer);
   }
 
+  @TargetApi(21)
+  public void updateMediaRecorder(boolean useSurfaceCapture)
+      throws InterruptedException, IOException {
+    final CapturerInstance capturerInstance = createCapturer(false /* initialize */);
+    final VideoTrackWithRenderer videoTrackWithRenderer =
+        createVideoTrackWithRenderer(capturerInstance.capturer);
+    // Wait for the camera to start so we can add and remove MediaRecorder.
+    assertTrue(videoTrackWithRenderer.rendererCallbacks.waitForNextFrameToRender() > 0);
+
+    final String videoOutPath = Environment.getExternalStorageDirectory().getPath()
+        + "/chromium_tests_root/testmediarecorder.mp4";
+    File outputFile = new File(videoOutPath);
+
+    // Create MediaRecorder object
+    MediaRecorder mediaRecorder = new MediaRecorder();
+    mediaRecorder.setVideoSource(
+        useSurfaceCapture ? MediaRecorder.VideoSource.SURFACE : MediaRecorder.VideoSource.CAMERA);
+    CamcorderProfile profile = CamcorderProfile.get(CamcorderProfile.QUALITY_480P);
+    profile.videoCodec = MediaRecorder.VideoEncoder.H264;
+    profile.videoBitRate = 2500000;
+    profile.videoFrameWidth = 640;
+    profile.videoFrameHeight = 480;
+    mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
+    mediaRecorder.setVideoFrameRate(profile.videoFrameRate);
+    mediaRecorder.setVideoSize(profile.videoFrameWidth, profile.videoFrameHeight);
+    mediaRecorder.setVideoEncodingBitRate(profile.videoBitRate);
+    mediaRecorder.setVideoEncoder(profile.videoCodec);
+    mediaRecorder.setOutputFile(outputFile.getPath());
+    mediaRecorder.prepare();
+
+    // Add MediaRecorder to camera pipeline.
+    final boolean[] addMediaRecorderSuccessful = new boolean[1];
+    final CountDownLatch addBarrier = new CountDownLatch(1);
+    CameraVideoCapturer.MediaRecorderHandler addMediaRecorderHandler =
+        new CameraVideoCapturer.MediaRecorderHandler() {
+          @Override
+          public void onMediaRecorderSuccess() {
+            addMediaRecorderSuccessful[0] = true;
+            addBarrier.countDown();
+          }
+          @Override
+          public void onMediaRecorderError(String errorDescription) {
+            addMediaRecorderSuccessful[0] = false;
+            addBarrier.countDown();
+          }
+        };
+    capturerInstance.capturer.addMediaRecorderToCamera(mediaRecorder, addMediaRecorderHandler);
+    // Wait until MediaRecoder has been added.
+    addBarrier.await();
+    // Check result.
+    assertTrue(addMediaRecorderSuccessful[0]);
+
+    // Start MediaRecorder and wait for a few frames to capture.
+    mediaRecorder.start();
+    for (int i = 0; i < 5; i++) {
+      assertTrue(videoTrackWithRenderer.rendererCallbacks.waitForNextFrameToRender() > 0);
+    }
+    mediaRecorder.stop();
+
+    // Remove MediaRecorder from camera pipeline.
+    final boolean[] removeMediaRecorderSuccessful = new boolean[1];
+    final CountDownLatch removeBarrier = new CountDownLatch(1);
+    CameraVideoCapturer.MediaRecorderHandler removeMediaRecorderHandler =
+        new CameraVideoCapturer.MediaRecorderHandler() {
+          @Override
+          public void onMediaRecorderSuccess() {
+            removeMediaRecorderSuccessful[0] = true;
+            removeBarrier.countDown();
+          }
+          @Override
+          public void onMediaRecorderError(String errorDescription) {
+            removeMediaRecorderSuccessful[0] = false;
+            removeBarrier.countDown();
+          }
+        };
+    capturerInstance.capturer.removeMediaRecorderFromCamera(removeMediaRecorderHandler);
+    // Wait until MediaRecoder has been removed.
+    removeBarrier.await();
+    // Check result.
+    assertTrue(removeMediaRecorderSuccessful[0]);
+    // Ensure that frames are received after removing MediaRecorder.
+    assertTrue(videoTrackWithRenderer.rendererCallbacks.waitForNextFrameToRender() > 0);
+    // Check that recorded file contains some data.
+    assertTrue(outputFile.length() > 0);
+
+    disposeCapturer(capturerInstance);
+    disposeVideoTrackWithRenderer(videoTrackWithRenderer);
+  }
+
   public void cameraEventsInvoked() throws InterruptedException {
     final CapturerInstance capturerInstance = createCapturer(true /* initialize */);
     startCapture(capturerInstance);

webrtc/sdk/android/src/java/org/webrtc/Camera2Session.java

@@ -21,11 +21,12 @@ import android.hardware.camera2.CameraManager;
 import android.hardware.camera2.CameraMetadata;
 import android.hardware.camera2.CaptureFailure;
 import android.hardware.camera2.CaptureRequest;
+import android.media.MediaRecorder;
 import android.os.Handler;
 import android.util.Range;
 import android.view.Surface;
 import android.view.WindowManager;
-import java.util.Arrays;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 import org.webrtc.CameraEnumerationAndroid.CaptureFormat;
@@ -49,6 +50,7 @@ class Camera2Session implements CameraSession {
   private final Context applicationContext;
   private final CameraManager cameraManager;
   private final SurfaceTextureHelper surfaceTextureHelper;
+  private final Surface mediaRecorderSurface;
   private final String cameraId;
   private final int width;
   private final int height;
@@ -123,9 +125,14 @@ class Camera2Session implements CameraSession {
       final SurfaceTexture surfaceTexture = surfaceTextureHelper.getSurfaceTexture();
       surfaceTexture.setDefaultBufferSize(captureFormat.width, captureFormat.height);
       surface = new Surface(surfaceTexture);
+      List<Surface> surfaces = new ArrayList<Surface>();
+      surfaces.add(surface);
+      if (mediaRecorderSurface != null) {
+        Logging.d(TAG, "Add MediaRecorder surface to capture session.");
+        surfaces.add(mediaRecorderSurface);
+      }
       try {
-        camera.createCaptureSession(
+        camera.createCaptureSession(surfaces, new CaptureSessionCallback(), cameraThreadHandler);
-            Arrays.asList(surface), new CaptureSessionCallback(), cameraThreadHandler);
       } catch (CameraAccessException e) {
         reportError("Failed to create capture session. " + e);
         return;
@@ -175,6 +182,10 @@ class Camera2Session implements CameraSession {
         chooseFocusMode(captureRequestBuilder);
 
         captureRequestBuilder.addTarget(surface);
+        if (mediaRecorderSurface != null) {
+          Logging.d(TAG, "Add MediaRecorder surface to CaptureRequest.Builder");
+          captureRequestBuilder.addTarget(mediaRecorderSurface);
+        }
         session.setRepeatingRequest(
             captureRequestBuilder.build(), new CameraCaptureCallback(), cameraThreadHandler);
       } catch (CameraAccessException e) {
@@ -280,15 +291,15 @@ class Camera2Session implements CameraSession {
 
   public static void create(CreateSessionCallback callback, Events events,
       Context applicationContext, CameraManager cameraManager,
-      SurfaceTextureHelper surfaceTextureHelper, String cameraId, int width, int height,
+      SurfaceTextureHelper surfaceTextureHelper, MediaRecorder mediaRecorder, String cameraId,
-      int framerate) {
+      int width, int height, int framerate) {
     new Camera2Session(callback, events, applicationContext, cameraManager, surfaceTextureHelper,
-        cameraId, width, height, framerate);
+        mediaRecorder, cameraId, width, height, framerate);
   }
 
   private Camera2Session(CreateSessionCallback callback, Events events, Context applicationContext,
-      CameraManager cameraManager, SurfaceTextureHelper surfaceTextureHelper, String cameraId,
+      CameraManager cameraManager, SurfaceTextureHelper surfaceTextureHelper,
-      int width, int height, int framerate) {
+      MediaRecorder mediaRecorder, String cameraId, int width, int height, int framerate) {
     Logging.d(TAG, "Create new camera2 session on camera " + cameraId);
 
     constructionTimeNs = System.nanoTime();
@@ -299,6 +310,7 @@ class Camera2Session implements CameraSession {
     this.applicationContext = applicationContext;
     this.cameraManager = cameraManager;
     this.surfaceTextureHelper = surfaceTextureHelper;
+    this.mediaRecorderSurface = (mediaRecorder != null) ? mediaRecorder.getSurface() : null;
     this.cameraId = cameraId;
     this.width = width;
     this.height = height;

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

@@ -11,6 +11,7 @@
 package org.webrtc;
 
 import android.content.Context;
+import android.media.MediaRecorder;
 import android.os.Handler;
 import android.os.Looper;
 import java.util.Arrays;
@@ -23,6 +24,13 @@ abstract class CameraCapturer implements CameraVideoCapturer {
     IN_PROGRESS, // Waiting for new switched capture session to start.
   }
 
+  enum MediaRecorderState {
+    IDLE, // No media recording update (add or remove) requested.
+    IDLE_TO_ACTIVE, // Waiting for new capture session with added MediaRecorder surface to start.
+    ACTIVE_TO_IDLE, // Waiting for new capture session with removed MediaRecorder surface to start.
+    ACTIVE, // MediaRecorder was successfully added to camera pipeline.
+  }
+
   private static final String TAG = "CameraCapturer";
   private final static int MAX_OPEN_CAMERA_ATTEMPTS = 3;
   private final static int OPEN_CAMERA_DELAY_MS = 500;
@@ -37,7 +45,9 @@ abstract class CameraCapturer implements CameraVideoCapturer {
         @Override
         public void onDone(CameraSession session) {
           checkIsOnCameraThread();
-          Logging.d(TAG, "Create session done");
+          Logging.d(TAG,
+              "Create session done. Switch state: " + switchState
+                  + ". MediaRecorder state: " + mediaRecorderState);
           uiThreadHandler.removeCallbacks(openCameraTimeoutRunnable);
           synchronized (stateLock) {
             capturerObserver.onCapturerStarted(true /* success */);
@@ -57,6 +67,19 @@ abstract class CameraCapturer implements CameraVideoCapturer {
               switchState = SwitchState.IDLE;
               switchCameraInternal(switchEventsHandler);
             }
+
+            if (mediaRecorderState == MediaRecorderState.IDLE_TO_ACTIVE
+                || mediaRecorderState == MediaRecorderState.ACTIVE_TO_IDLE) {
+              if (mediaRecorderEventsHandler != null) {
+                mediaRecorderEventsHandler.onMediaRecorderSuccess();
+                mediaRecorderEventsHandler = null;
+              }
+              if (mediaRecorderState == MediaRecorderState.IDLE_TO_ACTIVE) {
+                mediaRecorderState = MediaRecorderState.ACTIVE;
+              } else {
+                mediaRecorderState = MediaRecorderState.IDLE;
+              }
+            }
           }
         }
 
@@ -81,6 +104,14 @@ abstract class CameraCapturer implements CameraVideoCapturer {
                 switchState = SwitchState.IDLE;
               }
 
+              if (mediaRecorderState != MediaRecorderState.IDLE) {
+                if (mediaRecorderEventsHandler != null) {
+                  mediaRecorderEventsHandler.onMediaRecorderError(error);
+                  mediaRecorderEventsHandler = null;
+                }
+                mediaRecorderState = MediaRecorderState.IDLE;
+              }
+
               if (failureType == CameraSession.FailureType.DISCONNECTED) {
                 eventsHandler.onCameraDisconnected();
               } else {
@@ -88,8 +119,7 @@ abstract class CameraCapturer implements CameraVideoCapturer {
               }
             } else {
               Logging.w(TAG, "Opening camera failed, retry: " + error);
-
+              createSessionInternal(OPEN_CAMERA_DELAY_MS, null /* mediaRecorder */);
-              createSessionInternal(OPEN_CAMERA_DELAY_MS);
             }
           }
         }
@@ -213,6 +243,10 @@ abstract class CameraCapturer implements CameraVideoCapturer {
   private CameraStatistics cameraStatistics; /* guarded by stateLock */
   private boolean firstFrameObserved; /* guarded by stateLock */
 
+  // Variables used on camera thread - do not require stateLock synchronization.
+  private MediaRecorderState mediaRecorderState = MediaRecorderState.IDLE;
+  private MediaRecorderHandler mediaRecorderEventsHandler;
+
   public CameraCapturer(
       String cameraName, CameraEventsHandler eventsHandler, CameraEnumerator cameraEnumerator) {
     if (eventsHandler == null) {
@@ -277,17 +311,17 @@ abstract class CameraCapturer implements CameraVideoCapturer {
 
       sessionOpening = true;
       openAttemptsRemaining = MAX_OPEN_CAMERA_ATTEMPTS;
-      createSessionInternal(0);
+      createSessionInternal(0, null /* mediaRecorder */);
     }
   }
 
-  private void createSessionInternal(int delayMs) {
+  private void createSessionInternal(int delayMs, final MediaRecorder mediaRecorder) {
     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);
   }
@@ -349,6 +383,29 @@ abstract class CameraCapturer implements CameraVideoCapturer {
     });
   }
 
+  @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;
@@ -370,6 +427,13 @@ abstract class CameraCapturer implements CameraVideoCapturer {
     }
   }
 
+  private void reportCameraSwitchError(String error, CameraSwitchHandler switchEventsHandler) {
+    Logging.e(TAG, error);
+    if (switchEventsHandler != null) {
+      switchEventsHandler.onCameraSwitchError(error);
+    }
+  }
+
   private void switchCameraInternal(final CameraSwitchHandler switchEventsHandler) {
     Logging.d(TAG, "switchCamera internal");
 
@@ -384,18 +448,15 @@ abstract class CameraCapturer implements CameraVideoCapturer {
 
     synchronized (stateLock) {
       if (switchState != SwitchState.IDLE) {
-        Logging.d(TAG, "switchCamera switchInProgress");
+        reportCameraSwitchError("Camera switch already in progress.", switchEventsHandler);
-        if (switchEventsHandler != null) {
+        return;
-          switchEventsHandler.onCameraSwitchError("Camera switch already in progress.");
+      }
-        }
+      if (mediaRecorderState != MediaRecorderState.IDLE) {
+        reportCameraSwitchError("switchCamera: media recording is active", switchEventsHandler);
         return;
       }
-
       if (!sessionOpening && currentSession == null) {
-        Logging.d(TAG, "switchCamera: No session open");
+        reportCameraSwitchError("switchCamera: camera is not running.", switchEventsHandler);
-        if (switchEventsHandler != null) {
-          switchEventsHandler.onCameraSwitchError("Camera is not running.");
-        }
         return;
       }
 
@@ -424,11 +485,74 @@ abstract class CameraCapturer implements CameraVideoCapturer {
 
       sessionOpening = true;
       openAttemptsRemaining = 1;
-      createSessionInternal(0);
+      createSessionInternal(0, null /* mediaRecorder */);
     }
     Logging.d(TAG, "switchCamera done");
   }
 
+  private void reportUpdateMediaRecorderError(
+      String error, MediaRecorderHandler mediaRecoderEventsHandler) {
+    checkIsOnCameraThread();
+    Logging.e(TAG, error);
+    if (mediaRecoderEventsHandler != null) {
+      mediaRecoderEventsHandler.onMediaRecorderError(error);
+    }
+  }
+
+  private void updateMediaRecorderInternal(
+      MediaRecorder mediaRecorder, MediaRecorderHandler mediaRecoderEventsHandler) {
+    checkIsOnCameraThread();
+    boolean addMediaRecorder = (mediaRecorder != null);
+    Logging.d(TAG,
+        "updateMediaRecoderInternal internal. State: " + mediaRecorderState
+            + ". Switch state: " + switchState + ". Add MediaRecorder: " + addMediaRecorder);
+
+    synchronized (stateLock) {
+      if ((addMediaRecorder && mediaRecorderState != MediaRecorderState.IDLE)
+          || (!addMediaRecorder && mediaRecorderState != MediaRecorderState.ACTIVE)) {
+        reportUpdateMediaRecorderError(
+            "Incorrect state for MediaRecorder update.", mediaRecoderEventsHandler);
+        return;
+      }
+      if (switchState != SwitchState.IDLE) {
+        reportUpdateMediaRecorderError(
+            "MediaRecorder update while camera is switching.", mediaRecoderEventsHandler);
+        return;
+      }
+      if (currentSession == null) {
+        reportUpdateMediaRecorderError(
+            "MediaRecorder update while camera is closed.", mediaRecoderEventsHandler);
+        return;
+      }
+      if (sessionOpening) {
+        reportUpdateMediaRecorderError(
+            "MediaRecorder update while camera is still opening.", mediaRecoderEventsHandler);
+        return;
+      }
+
+      this.mediaRecorderEventsHandler = mediaRecoderEventsHandler;
+      mediaRecorderState =
+          addMediaRecorder ? MediaRecorderState.IDLE_TO_ACTIVE : MediaRecorderState.ACTIVE_TO_IDLE;
+
+      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, mediaRecorder);
+    }
+    Logging.d(TAG, "updateMediaRecoderInternal done");
+  }
+
   private void checkIsOnCameraThread() {
     if (Thread.currentThread() != cameraThreadHandler.getLooper().getThread()) {
       Logging.e(TAG, "Check is on camera thread failed.");
@@ -444,6 +568,6 @@ abstract class CameraCapturer implements CameraVideoCapturer {
 
   abstract protected void createCameraSession(
       CameraSession.CreateSessionCallback createSessionCallback, CameraSession.Events events,
-      Context applicationContext, SurfaceTextureHelper surfaceTextureHelper, String cameraName,
+      Context applicationContext, SurfaceTextureHelper surfaceTextureHelper,
-      int width, int height, int framerate);
+      MediaRecorder mediaRecoder, String cameraName, int width, int height, int framerate);
 }