Revert of Android: Make base interface for camera1 and camera2 (patchset #1 id:1 of https://codereview.webrtc.org/1994893002/ )

Reason for revert:
Still breaks downstream import.

Original issue's description:
> Reland of Android: Make base interface for camera1 and camera2 (patchset #1 id:1 of https://codereview.webrtc.org/1979583002/ )
>
> Reason for revert:
> Downstream code has been updated.
>
> Original issue's description:
> > Revert of Android: Make base interface for camera1 and camera2 (patchset #3 id:80001 of https://codereview.webrtc.org/1895483002/ )
> >
> > Reason for revert:
> > Breaks downstream import.
> >
> > Original issue's description:
> > > Android: Make base interface for camera1 and camera2
> > >
> > > This CL adds a new interface CameraVideoCapturer that extends VideoCapturer with a switchCamera() function. It also moves moves CameraEventsHandler, CameraStatistics, and CameraSwitchHandler from VideoCapturerAndroid to this new interface. The purpose is to prepare for a camera2 implementation that will use the same interfaces and helper class.
> > >
> > > BUG=webrtc:5519
> > >
> > > Committed: https://crrev.com/6bdacaddfb18edef1f0cdd778209f6b05a8f9210
> > > Cr-Commit-Position: refs/heads/master@{#12723}
> >
> > TBR=perkj@webrtc.org
> > # Skipping CQ checks because original CL landed less than 1 days ago.
> > NOPRESUBMIT=true
> > NOTREECHECKS=true
> > NOTRY=true
> > BUG=webrtc:5519
> >
> > Committed: https://crrev.com/181b5ffdf036427d92929667d9d43bbcff560435
> > Cr-Commit-Position: refs/heads/master@{#12727}
>
> TBR=perkj@webrtc.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=webrtc:5519
>
> Committed: https://crrev.com/d269b023bfe1c321798fe9c8dbd631a562914fe1
> Cr-Commit-Position: refs/heads/master@{#12807}

TBR=perkj@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:5519

Review-Url: https://codereview.webrtc.org/1994013004
Cr-Commit-Position: refs/heads/master@{#12809}

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

@@ -1,128 +0,0 @@
-/*
- *  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;
-
-/**
- * Base interface for camera1 and camera2 implementations. Extends VideoCapturer with a
- * switchCamera() function. Also provides subinterfaces for handling camera events, and a helper
- * class for detecting camera freezes.
- */
-public interface CameraVideoCapturer extends VideoCapturer {
-  /**
-   * Camera events handler - can be used to be notifed about camera events. The callbacks are
-   * executed from an arbitrary thread.
-   */
-  public interface CameraEventsHandler {
-    // Camera error handler - invoked when camera can not be opened
-    // or any camera exception happens on camera thread.
-    void onCameraError(String errorDescription);
-
-    // Invoked when camera stops receiving frames.
-    void onCameraFreezed(String errorDescription);
-
-    // Callback invoked when camera is opening.
-    void onCameraOpening(int cameraId);
-
-    // Callback invoked when first camera frame is available after camera is started.
-    void onFirstFrameAvailable();
-
-    // Callback invoked when camera is closed.
-    void onCameraClosed();
-  }
-
-  /**
-   * Camera switch handler - one of these functions are invoked with the result of switchCamera().
-   * The callback may be called on an arbitrary thread.
-   */
-  public interface CameraSwitchHandler {
-    // Invoked on success. |isFrontCamera| is true if the new camera is front facing.
-    void onCameraSwitchDone(boolean isFrontCamera);
-
-    // Invoked on failure, e.g. camera is stopped or only one camera available.
-    void onCameraSwitchError(String errorDescription);
-  }
-
-  /**
-   * Switch camera to the next valid camera id. This can only be called while the camera is running.
-   * This function can be called from any thread.
-   */
-  void switchCamera(CameraSwitchHandler switchEventsHandler);
-
-  /**
-   * 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
-   * thread.
-   */
-  public static class CameraStatistics {
-    private final static String TAG = "CameraStatistics";
-    private final static int CAMERA_OBSERVER_PERIOD_MS = 2000;
-    private final static int CAMERA_FREEZE_REPORT_TIMOUT_MS = 4000;
-
-    private final SurfaceTextureHelper surfaceTextureHelper;
-    private final CameraEventsHandler eventsHandler;
-    private int frameCount;
-    private int freezePeriodCount;
-    // Camera observer - monitors camera framerate. Observer is executed on camera thread.
-    private final Runnable cameraObserver = new Runnable() {
-      @Override
-      public void run() {
-        final int cameraFps = Math.round(frameCount * 1000.0f / CAMERA_OBSERVER_PERIOD_MS);
-        Logging.d(TAG, "Camera fps: " + cameraFps +".");
-        if (frameCount == 0) {
-          ++freezePeriodCount;
-          if (CAMERA_OBSERVER_PERIOD_MS * freezePeriodCount >= CAMERA_FREEZE_REPORT_TIMOUT_MS
-              && eventsHandler != null) {
-            Logging.e(TAG, "Camera freezed.");
-            if (surfaceTextureHelper.isTextureInUse()) {
-              // This can only happen if we are capturing to textures.
-              eventsHandler.onCameraFreezed("Camera failure. Client must return video buffers.");
-            } else {
-              eventsHandler.onCameraFreezed("Camera failure.");
-            }
-            return;
-          }
-        } else {
-          freezePeriodCount = 0;
-        }
-        frameCount = 0;
-        surfaceTextureHelper.getHandler().postDelayed(this, CAMERA_OBSERVER_PERIOD_MS);
-      }
-    };
-
-    public CameraStatistics(
-        SurfaceTextureHelper surfaceTextureHelper, CameraEventsHandler eventsHandler) {
-      if (surfaceTextureHelper == null) {
-        throw new IllegalArgumentException("SurfaceTextureHelper is null");
-      }
-      this.surfaceTextureHelper = surfaceTextureHelper;
-      this.eventsHandler = eventsHandler;
-      this.frameCount = 0;
-      this.freezePeriodCount = 0;
-      surfaceTextureHelper.getHandler().postDelayed(cameraObserver, CAMERA_OBSERVER_PERIOD_MS);
-    }
-
-    private void checkThread() {
-      if (Thread.currentThread() != surfaceTextureHelper.getHandler().getLooper().getThread()) {
-        throw new IllegalStateException("Wrong thread");
-      }
-    }
-
-    public void addFrame() {
-      checkThread();
-      ++frameCount;
-    }
-
-    public void release() {
-      checkThread();
-      surfaceTextureHelper.getHandler().removeCallbacks(cameraObserver);
-    }
-  }
-}

webrtc/api/java/android/org/webrtc/VideoCapturerAndroid.java

@@ -38,13 +38,14 @@ import java.util.concurrent.TimeUnit;
 // arbitrary Java threads. All public entry points are thread safe, and delegate the work to the
 // camera thread. The internal *OnCameraThread() methods must check |camera| for null to check if
 // the camera has been stopped.
-// TODO(magjed): This class name is now confusing - rename to Camera1VideoCapturer.
 @SuppressWarnings("deprecation")
 public class VideoCapturerAndroid implements
-    CameraVideoCapturer,
+    VideoCapturer,
     android.hardware.Camera.PreviewCallback,
     SurfaceTextureHelper.OnTextureFrameAvailableListener {
   private final static String TAG = "VideoCapturerAndroid";
+  private final static int CAMERA_OBSERVER_PERIOD_MS = 2000;
+  private final static int CAMERA_FREEZE_REPORT_TIMOUT_MS = 4000;
   private static final int CAMERA_STOP_TIMEOUT_MS = 7000;
 
   private boolean isDisposed = false;
@@ -59,7 +60,7 @@ public class VideoCapturerAndroid implements
   private final Object cameraIdLock = new Object();
   private int id;
   private android.hardware.Camera.CameraInfo info;
-  private CameraStatistics cameraStatistics;
+  private final CameraStatistics cameraStatistics;
   // Remember the requested format in case we want to switch cameras.
   private int requestedWidth;
   private int requestedHeight;
@@ -103,6 +104,84 @@ public class VideoCapturerAndroid implements
     }
   };
 
+  // Camera observer - monitors camera framerate. Observer is executed on camera thread.
+  private final Runnable cameraObserver = new Runnable() {
+    private int freezePeriodCount;
+    @Override
+    public void run() {
+      int cameraFramesCount = cameraStatistics.getAndResetFrameCount();
+      int cameraFps = (cameraFramesCount * 1000 + CAMERA_OBSERVER_PERIOD_MS / 2)
+          / CAMERA_OBSERVER_PERIOD_MS;
+
+      Logging.d(TAG, "Camera fps: " + cameraFps +".");
+      if (cameraFramesCount == 0) {
+        ++freezePeriodCount;
+        if (CAMERA_OBSERVER_PERIOD_MS * freezePeriodCount >= CAMERA_FREEZE_REPORT_TIMOUT_MS
+            && eventsHandler != null) {
+          Logging.e(TAG, "Camera freezed.");
+          if (surfaceHelper.isTextureInUse()) {
+            // This can only happen if we are capturing to textures.
+            eventsHandler.onCameraFreezed("Camera failure. Client must return video buffers.");
+          } else {
+            eventsHandler.onCameraFreezed("Camera failure.");
+          }
+          return;
+        }
+      } else {
+        freezePeriodCount = 0;
+      }
+      maybePostDelayedOnCameraThread(CAMERA_OBSERVER_PERIOD_MS, this);
+    }
+  };
+
+  private static class CameraStatistics {
+    private int frameCount = 0;
+    private final ThreadUtils.ThreadChecker threadChecker = new ThreadUtils.ThreadChecker();
+
+    CameraStatistics() {
+      threadChecker.detachThread();
+    }
+
+    public void addFrame() {
+      threadChecker.checkIsOnValidThread();
+      ++frameCount;
+    }
+
+    public int getAndResetFrameCount() {
+      threadChecker.checkIsOnValidThread();
+      int count = frameCount;
+      frameCount = 0;
+      return count;
+    }
+  }
+
+  public static interface CameraEventsHandler {
+    // Camera error handler - invoked when camera can not be opened
+    // or any camera exception happens on camera thread.
+    void onCameraError(String errorDescription);
+
+    // Invoked when camera stops receiving frames
+    void onCameraFreezed(String errorDescription);
+
+    // Callback invoked when camera is opening.
+    void onCameraOpening(int cameraId);
+
+    // Callback invoked when first camera frame is available after camera is opened.
+    void onFirstFrameAvailable();
+
+    // Callback invoked when camera closed.
+    void onCameraClosed();
+  }
+
+  // Camera switch handler - one of these functions are invoked with the result of switchCamera().
+  // The callback may be called on an arbitrary thread.
+  public interface CameraSwitchHandler {
+    // Invoked on success. |isFrontCamera| is true if the new camera is front facing.
+    void onCameraSwitchDone(boolean isFrontCamera);
+    // Invoked on failure, e.g. camera is stopped or only one camera available.
+    void onCameraSwitchError(String errorDescription);
+  }
+
   public static VideoCapturerAndroid create(String name,
       CameraEventsHandler eventsHandler) {
     return VideoCapturerAndroid.create(name, eventsHandler, false /* captureToTexture */);
@@ -137,7 +216,6 @@ public class VideoCapturerAndroid implements
 
   // Switch camera to the next valid camera id. This can only be called while
   // the camera is running.
-  @Override
   public void switchCamera(final CameraSwitchHandler switchEventsHandler) {
     if (android.hardware.Camera.getNumberOfCameras() < 2) {
       if (switchEventsHandler != null) {
@@ -221,6 +299,7 @@ public class VideoCapturerAndroid implements
     this.id = cameraId;
     this.eventsHandler = eventsHandler;
     isCapturingToTexture = captureToTexture;
+    cameraStatistics = new CameraStatistics();
     Logging.d(TAG, "VideoCapturerAndroid isCapturingToTexture : " + isCapturingToTexture);
   }
 
@@ -381,7 +460,7 @@ public class VideoCapturerAndroid implements
       }
 
       // Start camera observer.
-      cameraStatistics = new CameraStatistics(surfaceHelper, eventsHandler);
+      maybePostDelayedOnCameraThread(CAMERA_OBSERVER_PERIOD_MS, cameraObserver);
       return;
     } catch (RuntimeException e) {
       error = e;
@@ -534,10 +613,8 @@ public class VideoCapturerAndroid implements
     if (surfaceHelper != null) {
       surfaceHelper.stopListening();
     }
-    if (cameraStatistics != null) {
+    cameraThreadHandler.removeCallbacks(cameraObserver);
-      cameraStatistics.release();
+    cameraStatistics.getAndResetFrameCount();
-      cameraStatistics = null;
-    }
     Logging.d(TAG, "Stop preview.");
     if (camera != null) {
       camera.stopPreview();