VideoCapturerAndroid: Add custom nativeCreateVideoCapturer()

This CL shouldn't make any functional changes. It adds a new VideoCapturerAndroid.nativeCreateVideoCapturer() instead of always using VideoCapturer.nativeCreateVideoCapturer(). The purpose is to simplify androidvideocapturer_jni and VideoCapturerAndroid.create(). This way, it is possible to use the ctor instead of VideoCapturerAndroid.init() to initialize variables, and they can be made final etc.

R=perkj@webrtc.org

Review URL: https://codereview.webrtc.org/1360173002 .

Cr-Commit-Position: refs/heads/master@{#10171}

talk/app/webrtc/java/android/org/webrtc/VideoCapturerAndroid.java

@@ -92,7 +92,7 @@ public class VideoCapturerAndroid extends VideoCapturer implements PreviewCallba
   private final Object pendingCameraSwitchLock = new Object();
   private volatile boolean pendingCameraSwitch;
   private CapturerObserver frameObserver = null;
-  private CameraErrorHandler errorHandler = null;
+  private final CameraErrorHandler errorHandler;
 
   // Camera error callback.
   private final Camera.ErrorCallback cameraErrorCallback =
@@ -155,15 +155,14 @@ public class VideoCapturerAndroid extends VideoCapturer implements PreviewCallba
     void onCameraSwitchError(String errorDescription);
   }
 
-  public static VideoCapturerAndroid create(String name,
-      CameraErrorHandler errorHandler) {
-    VideoCapturer capturer = VideoCapturer.create(name);
-    if (capturer != null) {
-      VideoCapturerAndroid capturerAndroid = (VideoCapturerAndroid) capturer;
-      capturerAndroid.errorHandler = errorHandler;
-      return capturerAndroid;
+  public static VideoCapturerAndroid create(String name, CameraErrorHandler errorHandler) {
+    final int cameraId = lookupDeviceName(name);
+    if (cameraId == -1) {
+      return null;
     }
-    return null;
+    final VideoCapturerAndroid capturer = new VideoCapturerAndroid(cameraId, errorHandler);
+    capturer.setNativeCapturer(nativeCreateVideoCapturer(capturer));
+    return capturer;
   }
 
   // Switch camera to the next valid camera id. This can only be called while
@@ -244,8 +243,15 @@ public class VideoCapturerAndroid extends VideoCapturer implements PreviewCallba
     return CameraEnumerationAndroid.getSupportedFormatsAsJson(getCurrentCameraId());
   }
 
-  private VideoCapturerAndroid() {
+  // Called from native VideoCapturer_nativeCreateVideoCapturer.
+  private VideoCapturerAndroid(int cameraId) {
+    this(cameraId, null);
+  }
+
+  private VideoCapturerAndroid(int cameraId, CameraErrorHandler errorHandler) {
     Logging.d(TAG, "VideoCapturerAndroid");
+    this.id = cameraId;
+    this.errorHandler = errorHandler;
     cameraThread = new HandlerThread(TAG);
     cameraThread.start();
     cameraThreadHandler = new Handler(cameraThread.getLooper());
@@ -258,30 +264,22 @@ public class VideoCapturerAndroid extends VideoCapturer implements PreviewCallba
     }
   }
 
-  // Called by native code.
-  // Initializes local variables for the camera named |deviceName|. If |deviceName| is empty, the
-  // first available device is used in order to be compatible with the generic VideoCapturer class.
-  boolean init(String deviceName) {
-    Logging.d(TAG, "init: " + deviceName);
-    if (deviceName == null)
-      return false;
-
+  // Returns the camera index for camera with name |deviceName|, or -1 if no such camera can be
+  // found. If |deviceName| is empty, the first available device is used.
+  private static int lookupDeviceName(String deviceName) {
+    Logging.d(TAG, "lookupDeviceName: " + deviceName);
+    if (deviceName == null || Camera.getNumberOfCameras() == 0) {
+      return -1;
+    }
     if (deviceName.isEmpty()) {
-      synchronized (cameraIdLock) {
-        this.id = 0;
-      }
-      return true;
-    } else {
-      for (int i = 0; i < Camera.getNumberOfCameras(); ++i) {
-        if (deviceName.equals(CameraEnumerationAndroid.getDeviceName(i))) {
-          synchronized (cameraIdLock) {
-            this.id = i;
-          }
-          return true;
-        }
+      return 0;
+    }
+    for (int i = 0; i < Camera.getNumberOfCameras(); ++i) {
+      if (deviceName.equals(CameraEnumerationAndroid.getDeviceName(i))) {
+        return i;
       }
     }
-    return false;
+    return -1;
   }
 
   // Called by native code to quit the camera thread. This needs to be done manually, otherwise the
@@ -769,4 +767,6 @@ public class VideoCapturerAndroid extends VideoCapturer implements PreviewCallba
     private native void nativeOnOutputFormatRequest(long nativeCapturer,
         int width, int height, int fps);
   }
+
+  private static native long nativeCreateVideoCapturer(VideoCapturerAndroid videoCapturer);
 }

talk/app/webrtc/java/jni/androidvideocapturer_jni.cc

@@ -46,22 +46,6 @@ int AndroidVideoCapturerJni::SetAndroidObjects(JNIEnv* jni,
   return 0;
 }
 
-// static
-rtc::scoped_refptr<AndroidVideoCapturerJni>
-AndroidVideoCapturerJni::Create(JNIEnv* jni,
-                                jobject j_video_capture,
-                                jstring device_name) {
-  LOG(LS_INFO) << "AndroidVideoCapturerJni::Create";
-  rtc::scoped_refptr<AndroidVideoCapturerJni> capturer(
-      new rtc::RefCountedObject<AndroidVideoCapturerJni>(jni, j_video_capture));
-
-  if (capturer->Init(device_name)) {
-    return capturer;
-  }
-  LOG(LS_ERROR) << "AndroidVideoCapturerJni init fails";
-  return nullptr;
-}
-
 AndroidVideoCapturerJni::AndroidVideoCapturerJni(JNIEnv* jni,
                                                  jobject j_video_capturer)
     : j_capturer_global_(jni, j_video_capturer),
@@ -76,16 +60,6 @@ AndroidVideoCapturerJni::AndroidVideoCapturerJni(JNIEnv* jni,
   thread_checker_.DetachFromThread();
 }
 
-bool AndroidVideoCapturerJni::Init(jstring device_name) {
-  const jmethodID m(GetMethodID(
-        jni(), *j_video_capturer_class_, "init", "(Ljava/lang/String;)Z"));
-  if (!jni()->CallBooleanMethod(*j_capturer_global_, m, device_name)) {
-    return false;
-  }
-  CHECK_EXCEPTION(jni()) << "error during CallVoidMethod";
-  return true;
-}
-
 AndroidVideoCapturerJni::~AndroidVideoCapturerJni() {
   LOG(LS_INFO) << "AndroidVideoCapturerJni dtor";
   jni()->CallVoidMethod(
@@ -246,4 +220,14 @@ JOW(void, VideoCapturerAndroid_00024NativeObserver_nativeOnOutputFormatRequest)
       j_width, j_height, j_fps);
 }
 
+JOW(jlong, VideoCapturerAndroid_nativeCreateVideoCapturer)
+    (JNIEnv* jni, jclass, jobject j_video_capturer) {
+  rtc::scoped_refptr<webrtc::AndroidVideoCapturerDelegate> delegate =
+      new rtc::RefCountedObject<AndroidVideoCapturerJni>(jni, j_video_capturer);
+  rtc::scoped_ptr<cricket::VideoCapturer> capturer(
+      new webrtc::AndroidVideoCapturer(delegate));
+  // Caller takes ownership of the cricket::VideoCapturer* pointer.
+  return jlongFromPointer(capturer.release());
+}
+
 }  // namespace webrtc_jni

talk/app/webrtc/java/jni/androidvideocapturer_jni.h

@@ -46,12 +46,7 @@ class AndroidVideoCapturerJni : public webrtc::AndroidVideoCapturerDelegate {
  public:
   static int SetAndroidObjects(JNIEnv* jni, jobject appliction_context);
 
-  // Creates a new instance of AndroidVideoCapturerJni. Returns a nullptr if
-  // it can't be created. This happens if |device_name| is invalid.
-  static rtc::scoped_refptr<AndroidVideoCapturerJni> Create(
-      JNIEnv* jni,
-      jobject j_video_capture, // Instance of VideoCapturerAndroid
-      jstring device_name); // Name of the camera to use.
+  AndroidVideoCapturerJni(JNIEnv* jni, jobject j_video_capturer);
 
   void Start(int width, int height, int framerate,
              webrtc::AndroidVideoCapturer* capturer) override;
@@ -68,12 +63,11 @@ class AndroidVideoCapturerJni : public webrtc::AndroidVideoCapturerDelegate {
                        int rotation,
                        int64 time_stamp);
   void OnOutputFormatRequest(int width, int height, int fps);
-protected:
-  AndroidVideoCapturerJni(JNIEnv* jni, jobject j_video_capturer);
+
+ protected:
   ~AndroidVideoCapturerJni();
 
-private:
-  bool Init(jstring device_name);
+ private:
   void ReturnBuffer(int64 time_stamp);
   JNIEnv* jni();
 

talk/app/webrtc/java/jni/peerconnection_jni.cc

@@ -1672,17 +1672,21 @@ JOW(jobject, VideoCapturer_nativeCreateVideoCapturer)(
 #if defined(ANDROID)
   jclass j_video_capturer_class(
       FindClass(jni, "org/webrtc/VideoCapturerAndroid"));
-  const jmethodID j_videocapturer_ctor(GetMethodID(
-      jni, j_video_capturer_class, "<init>", "()V"));
-  jobject j_video_capturer = jni->NewObject(j_video_capturer_class,
-                                            j_videocapturer_ctor);
-  CHECK_EXCEPTION(jni) << "error during NewObject";
-
-  rtc::scoped_refptr<AndroidVideoCapturerJni> delegate =
-      AndroidVideoCapturerJni::Create(jni, j_video_capturer, j_device_name);
-  if (!delegate.get())
+  const int camera_id = jni->CallStaticIntMethod(
+      j_video_capturer_class,
+      GetStaticMethodID(jni, j_video_capturer_class, "lookupDeviceName",
+                        "(Ljava/lang/String;)I"),
+      j_device_name);
+  CHECK_EXCEPTION(jni) << "error during VideoCapturerAndroid.lookupDeviceName";
+  if (camera_id == -1)
     return nullptr;
-  rtc::scoped_ptr<webrtc::AndroidVideoCapturer> capturer(
+  jobject j_video_capturer = jni->NewObject(
+      j_video_capturer_class,
+      GetMethodID(jni, j_video_capturer_class, "<init>", "(I)V"), camera_id);
+  CHECK_EXCEPTION(jni) << "error during creation of VideoCapturerAndroid";
+  rtc::scoped_refptr<webrtc::AndroidVideoCapturerDelegate> delegate =
+      new rtc::RefCountedObject<AndroidVideoCapturerJni>(jni, j_video_capturer);
+  rtc::scoped_ptr<cricket::VideoCapturer> capturer(
       new webrtc::AndroidVideoCapturer(delegate));
 
 #else
@@ -1712,7 +1716,7 @@ JOW(jobject, VideoCapturer_nativeCreateVideoCapturer)(
       jni, j_video_capturer_class, "setNativeCapturer", "(J)V"));
   jni->CallVoidMethod(j_video_capturer,
                       j_videocapturer_set_native_capturer,
-                      (jlong)capturer.release());
+                      jlongFromPointer(capturer.release()));
   CHECK_EXCEPTION(jni) << "error during setNativeCapturer";
   return j_video_capturer;
 }