sdk/android/api/org/webrtc/SurfaceTextureHelper.java - src - Git at Google

 /*
  *  Copyright 2015 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.annotation.TargetApi;
 import android.graphics.SurfaceTexture;
 import android.opengl.GLES11Ext;
 import android.opengl.GLES20;
 import android.os.Build;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.support.annotation.Nullable;
 import java.util.concurrent.Callable;
 import org.webrtc.EglBase.Context;
 import org.webrtc.TextureBufferImpl.RefCountMonitor;
 import org.webrtc.VideoFrame.TextureBuffer;

 /**
  * Helper class for using a SurfaceTexture to create WebRTC VideoFrames. In order to create WebRTC
  * VideoFrames, render onto the SurfaceTexture. The frames will be delivered to the listener. Only
  * one texture frame can be in flight at once, so the frame must be released in order to receive a
  * new frame. Call stopListening() to stop receiveing new frames. Call dispose to release all
  * resources once the texture frame is released.
  */
 public class SurfaceTextureHelper {
   /**
    * Interface for monitoring texture buffers created from this SurfaceTexture. Since only one
    * texture buffer can exist at a time, this can be used to monitor for stuck frames.
    */
   public interface FrameRefMonitor {
     /** A new frame was created. New frames start with ref count of 1. */
     void onNewBuffer(TextureBuffer textureBuffer);
     /** Ref count of the frame was incremented by the calling thread. */
     void onRetainBuffer(TextureBuffer textureBuffer);
     /** Ref count of the frame was decremented by the calling thread. */
     void onReleaseBuffer(TextureBuffer textureBuffer);
     /** Frame was destroyed (ref count reached 0). */
     void onDestroyBuffer(TextureBuffer textureBuffer);
   }

   private static final String TAG = "SurfaceTextureHelper";
   /**
    * Construct a new SurfaceTextureHelper sharing OpenGL resources with |sharedContext|. A dedicated
    * thread and handler is created for handling the SurfaceTexture. May return null if EGL fails to
    * initialize a pixel buffer surface and make it current. If alignTimestamps is true, the frame
    * timestamps will be aligned to rtc::TimeNanos(). If frame timestamps are aligned to
    * rtc::TimeNanos() there is no need for aligning timestamps again in
    * PeerConnectionFactory.createVideoSource(). This makes the timestamps more accurate and
    * closer to actual creation time.
    */
   public static SurfaceTextureHelper create(final String threadName,
       final EglBase.Context sharedContext, boolean alignTimestamps, final YuvConverter yuvConverter,
       FrameRefMonitor frameRefMonitor) {
     final HandlerThread thread = new HandlerThread(threadName);
     thread.start();
     final Handler handler = new Handler(thread.getLooper());

     // The onFrameAvailable() callback will be executed on the SurfaceTexture ctor thread. See:
     // http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/5.1.1_r1/android/graphics/SurfaceTexture.java#195.
     // Therefore, in order to control the callback thread on API lvl < 21, the SurfaceTextureHelper
     // is constructed on the |handler| thread.
     return ThreadUtils.invokeAtFrontUninterruptibly(handler, new Callable<SurfaceTextureHelper>() {
       @Nullable
       @Override
       public SurfaceTextureHelper call() {
         try {
           return new SurfaceTextureHelper(
               sharedContext, handler, alignTimestamps, yuvConverter, frameRefMonitor);
         } catch (RuntimeException e) {
           Logging.e(TAG, threadName + " create failure", e);
           return null;
         }
       }
     });
   }

   /**
    * Same as above with alignTimestamps set to false and yuvConverter set to new YuvConverter.
    *
    * @see #create(String, EglBase.Context, boolean, YuvConverter, FrameRefMonitor)
    */
   public static SurfaceTextureHelper create(
       final String threadName, final EglBase.Context sharedContext) {
     return create(threadName, sharedContext, /* alignTimestamps= */ false, new YuvConverter(),
         /*frameRefMonitor=*/null);
   }

   /**
    * Same as above with yuvConverter set to new YuvConverter.
    *
    * @see #create(String, EglBase.Context, boolean, YuvConverter, FrameRefMonitor)
    */
   public static SurfaceTextureHelper create(
       final String threadName, final EglBase.Context sharedContext, boolean alignTimestamps) {
     return create(
         threadName, sharedContext, alignTimestamps, new YuvConverter(), /*frameRefMonitor=*/null);
   }

   /**
    * Create a SurfaceTextureHelper without frame ref monitor.
    *
    * @see #create(String, EglBase.Context, boolean, YuvConverter, FrameRefMonitor)
    */
   public static SurfaceTextureHelper create(final String threadName,
       final EglBase.Context sharedContext, boolean alignTimestamps, YuvConverter yuvConverter) {
     return create(
         threadName, sharedContext, alignTimestamps, yuvConverter, /*frameRefMonitor=*/null);
   }

   private final RefCountMonitor textureRefCountMonitor = new RefCountMonitor() {
     @Override
     public void onRetain(TextureBufferImpl textureBuffer) {
       if (frameRefMonitor != null) {
         frameRefMonitor.onRetainBuffer(textureBuffer);
       }
     }

     @Override
     public void onRelease(TextureBufferImpl textureBuffer) {
       if (frameRefMonitor != null) {
         frameRefMonitor.onReleaseBuffer(textureBuffer);
       }
     }

     @Override
     public void onDestroy(TextureBufferImpl textureBuffer) {
       returnTextureFrame();
       if (frameRefMonitor != null) {
         frameRefMonitor.onDestroyBuffer(textureBuffer);
       }
     }
   };

   private final Handler handler;
   private final EglBase eglBase;
   private final SurfaceTexture surfaceTexture;
   private final int oesTextureId;
   private final YuvConverter yuvConverter;
   @Nullable private final TimestampAligner timestampAligner;
   private final FrameRefMonitor frameRefMonitor;

   // These variables are only accessed from the |handler| thread.
   @Nullable private VideoSink listener;
   // The possible states of this class.
   private boolean hasPendingTexture;
   private volatile boolean isTextureInUse;
   private boolean isQuitting;
   private int frameRotation;
   private int textureWidth;
   private int textureHeight;
   // |pendingListener| is set in setListener() and the runnable is posted to the handler thread.
   // setListener() is not allowed to be called again before stopListening(), so this is thread safe.
   @Nullable private VideoSink pendingListener;
   final Runnable setListenerRunnable = new Runnable() {
     @Override
     public void run() {
       Logging.d(TAG, "Setting listener to " + pendingListener);
       listener = pendingListener;
       pendingListener = null;
       // May have a pending frame from the previous capture session - drop it.
       if (hasPendingTexture) {
         // Calling updateTexImage() is neccessary in order to receive new frames.
         updateTexImage();
         hasPendingTexture = false;
       }
     }
   };

   private SurfaceTextureHelper(Context sharedContext, Handler handler, boolean alignTimestamps,
       YuvConverter yuvConverter, FrameRefMonitor frameRefMonitor) {
     if (handler.getLooper().getThread() != Thread.currentThread()) {
       throw new IllegalStateException("SurfaceTextureHelper must be created on the handler thread");
     }
     this.handler = handler;
     this.timestampAligner = alignTimestamps ? new TimestampAligner() : null;
     this.yuvConverter = yuvConverter;
     this.frameRefMonitor = frameRefMonitor;

     eglBase = EglBase.create(sharedContext, EglBase.CONFIG_PIXEL_BUFFER);
     try {
       // Both these statements have been observed to fail on rare occasions, see BUG=webrtc:5682.
       eglBase.createDummyPbufferSurface();
       eglBase.makeCurrent();
     } catch (RuntimeException e) {
       // Clean up before rethrowing the exception.
       eglBase.release();
       handler.getLooper().quit();
       throw e;
     }

     oesTextureId = GlUtil.generateTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES);
     surfaceTexture = new SurfaceTexture(oesTextureId);
     setOnFrameAvailableListener(surfaceTexture, (SurfaceTexture st) -> {
       if (hasPendingTexture) {
         Logging.d(TAG, "A frame is already pending, dropping frame.");
       }

       hasPendingTexture = true;
       tryDeliverTextureFrame();
     }, handler);
   }

   @TargetApi(21)
   private static void setOnFrameAvailableListener(SurfaceTexture surfaceTexture,
       SurfaceTexture.OnFrameAvailableListener listener, Handler handler) {
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
       surfaceTexture.setOnFrameAvailableListener(listener, handler);
     } else {
       // The documentation states that the listener will be called on an arbitrary thread, but in
       // pratice, it is always the thread on which the SurfaceTexture was constructed. There are
       // assertions in place in case this ever changes. For API >= 21, we use the new API to
       // explicitly specify the handler.
       surfaceTexture.setOnFrameAvailableListener(listener);
     }
   }

   /**
    * Start to stream textures to the given |listener|. If you need to change listener, you need to
    * call stopListening() first.
    */
   public void startListening(final VideoSink listener) {
     if (this.listener != null || this.pendingListener != null) {
       throw new IllegalStateException("SurfaceTextureHelper listener has already been set.");
     }
     this.pendingListener = listener;
     handler.post(setListenerRunnable);
   }

   /**
    * Stop listening. The listener set in startListening() is guaranteded to not receive any more
    * onFrame() callbacks after this function returns.
    */
   public void stopListening() {
     Logging.d(TAG, "stopListening()");
     handler.removeCallbacks(setListenerRunnable);
     ThreadUtils.invokeAtFrontUninterruptibly(handler, () -> {
       listener = null;
       pendingListener = null;
     });
   }

   /**
    * Use this function to set the texture size. Note, do not call setDefaultBufferSize() yourself
    * since this class needs to be aware of the texture size.
    */
   public void setTextureSize(int textureWidth, int textureHeight) {
     if (textureWidth <= 0) {
       throw new IllegalArgumentException("Texture width must be positive, but was " + textureWidth);
     }
     if (textureHeight <= 0) {
       throw new IllegalArgumentException(
           "Texture height must be positive, but was " + textureHeight);
     }
     surfaceTexture.setDefaultBufferSize(textureWidth, textureHeight);
     handler.post(() -> {
       this.textureWidth = textureWidth;
       this.textureHeight = textureHeight;
       tryDeliverTextureFrame();
     });
   }

   /**
    * Forces a frame to be produced. If no new frame is available, the last frame is sent to the
    * listener again.
    */
   public void forceFrame() {
     handler.post(() -> {
       hasPendingTexture = true;
       tryDeliverTextureFrame();
     });
   }

   /** Set the rotation of the delivered frames. */
   public void setFrameRotation(int rotation) {
     handler.post(() -> this.frameRotation = rotation);
   }

   /**
    * Retrieve the underlying SurfaceTexture. The SurfaceTexture should be passed in to a video
    * producer such as a camera or decoder.
    */
   public SurfaceTexture getSurfaceTexture() {
     return surfaceTexture;
   }

   /** Retrieve the handler that calls onFrame(). This handler is valid until dispose() is called. */
   public Handler getHandler() {
     return handler;
   }

   /**
    * This function is called when the texture frame is released. Only one texture frame can be in
    * flight at once, so this function must be called before a new frame is delivered.
    */
   private void returnTextureFrame() {
     handler.post(() -> {
       isTextureInUse = false;
       if (isQuitting) {
         release();
       } else {
         tryDeliverTextureFrame();
       }
     });
   }

   public boolean isTextureInUse() {
     return isTextureInUse;
   }

   /**
    * Call disconnect() to stop receiving frames. OpenGL resources are released and the handler is
    * stopped when the texture frame has been released. You are guaranteed to not receive any more
    * onFrame() after this function returns.
    */
   public void dispose() {
     Logging.d(TAG, "dispose()");
     ThreadUtils.invokeAtFrontUninterruptibly(handler, () -> {
       isQuitting = true;
       if (!isTextureInUse) {
         release();
       }
     });
   }

   /**
    * Posts to the correct thread to convert |textureBuffer| to I420.
    *
    * @deprecated Use toI420() instead.
    */
   @Deprecated
   public VideoFrame.I420Buffer textureToYuv(final TextureBuffer textureBuffer) {
     return textureBuffer.toI420();
   }

   private void updateTexImage() {
     // SurfaceTexture.updateTexImage apparently can compete and deadlock with eglSwapBuffers,
     // as observed on Nexus 5. Therefore, synchronize it with the EGL functions.
     // See https://bugs.chromium.org/p/webrtc/issues/detail?id=5702 for more info.
     synchronized (EglBase.lock) {
       surfaceTexture.updateTexImage();
     }
   }

   private void tryDeliverTextureFrame() {
     if (handler.getLooper().getThread() != Thread.currentThread()) {
       throw new IllegalStateException("Wrong thread.");
     }
     if (isQuitting || !hasPendingTexture || isTextureInUse || listener == null) {
       return;
     }
     if (textureWidth == 0 || textureHeight == 0) {
       // Information about the resolution needs to be provided by a call to setTextureSize() before
       // frames are produced.
       Logging.w(TAG, "Texture size has not been set.");
       return;
     }
     isTextureInUse = true;
     hasPendingTexture = false;

     updateTexImage();

     final float[] transformMatrix = new float[16];
     surfaceTexture.getTransformMatrix(transformMatrix);
     long timestampNs = surfaceTexture.getTimestamp();
     if (timestampAligner != null) {
       timestampNs = timestampAligner.translateTimestamp(timestampNs);
     }
     final VideoFrame.TextureBuffer buffer =
         new TextureBufferImpl(textureWidth, textureHeight, TextureBuffer.Type.OES, oesTextureId,
             RendererCommon.convertMatrixToAndroidGraphicsMatrix(transformMatrix), handler,
             yuvConverter, textureRefCountMonitor);
     if (frameRefMonitor != null) {
       frameRefMonitor.onNewBuffer(buffer);
     }
     final VideoFrame frame = new VideoFrame(buffer, frameRotation, timestampNs);
     listener.onFrame(frame);
     frame.release();
   }

   private void release() {
     if (handler.getLooper().getThread() != Thread.currentThread()) {
       throw new IllegalStateException("Wrong thread.");
     }
     if (isTextureInUse || !isQuitting) {
       throw new IllegalStateException("Unexpected release.");
     }
     yuvConverter.release();
     GLES20.glDeleteTextures(1, new int[] {oesTextureId}, 0);
     surfaceTexture.release();
     eglBase.release();
     handler.getLooper().quit();
     if (timestampAligner != null) {
       timestampAligner.dispose();
     }
   }
 }
	/*
	* Copyright 2015 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.annotation.TargetApi;
	import android.graphics.SurfaceTexture;
	import android.opengl.GLES11Ext;
	import android.opengl.GLES20;
	import android.os.Build;
	import android.os.Handler;
	import android.os.HandlerThread;
	import android.support.annotation.Nullable;
	import java.util.concurrent.Callable;
	import org.webrtc.EglBase.Context;
	import org.webrtc.TextureBufferImpl.RefCountMonitor;
	import org.webrtc.VideoFrame.TextureBuffer;

	/**
	* Helper class for using a SurfaceTexture to create WebRTC VideoFrames. In order to create WebRTC
	* VideoFrames, render onto the SurfaceTexture. The frames will be delivered to the listener. Only
	* one texture frame can be in flight at once, so the frame must be released in order to receive a
	* new frame. Call stopListening() to stop receiveing new frames. Call dispose to release all
	* resources once the texture frame is released.
	*/
	public class SurfaceTextureHelper {
	/**
	* Interface for monitoring texture buffers created from this SurfaceTexture. Since only one
	* texture buffer can exist at a time, this can be used to monitor for stuck frames.
	*/
	public interface FrameRefMonitor {
	/** A new frame was created. New frames start with ref count of 1. */
	void onNewBuffer(TextureBuffer textureBuffer);
	/** Ref count of the frame was incremented by the calling thread. */
	void onRetainBuffer(TextureBuffer textureBuffer);
	/** Ref count of the frame was decremented by the calling thread. */
	void onReleaseBuffer(TextureBuffer textureBuffer);
	/** Frame was destroyed (ref count reached 0). */
	void onDestroyBuffer(TextureBuffer textureBuffer);
	}

	private static final String TAG = "SurfaceTextureHelper";
	/**
	* Construct a new SurfaceTextureHelper sharing OpenGL resources with \|sharedContext\|. A dedicated
	* thread and handler is created for handling the SurfaceTexture. May return null if EGL fails to
	* initialize a pixel buffer surface and make it current. If alignTimestamps is true, the frame
	* timestamps will be aligned to rtc::TimeNanos(). If frame timestamps are aligned to
	* rtc::TimeNanos() there is no need for aligning timestamps again in
	* PeerConnectionFactory.createVideoSource(). This makes the timestamps more accurate and
	* closer to actual creation time.
	*/
	public static SurfaceTextureHelper create(final String threadName,
	final EglBase.Context sharedContext, boolean alignTimestamps, final YuvConverter yuvConverter,
	FrameRefMonitor frameRefMonitor) {
	final HandlerThread thread = new HandlerThread(threadName);
	thread.start();
	final Handler handler = new Handler(thread.getLooper());

	// The onFrameAvailable() callback will be executed on the SurfaceTexture ctor thread. See:
	// http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/5.1.1_r1/android/graphics/SurfaceTexture.java#195.
	// Therefore, in order to control the callback thread on API lvl < 21, the SurfaceTextureHelper
	// is constructed on the \|handler\| thread.
	return ThreadUtils.invokeAtFrontUninterruptibly(handler, new Callable<SurfaceTextureHelper>() {
	@Nullable
	@Override
	public SurfaceTextureHelper call() {
	try {
	return new SurfaceTextureHelper(
	sharedContext, handler, alignTimestamps, yuvConverter, frameRefMonitor);
	} catch (RuntimeException e) {
	Logging.e(TAG, threadName + " create failure", e);
	return null;
	}
	}
	});
	}

	/**
	* Same as above with alignTimestamps set to false and yuvConverter set to new YuvConverter.
	*
	* @see #create(String, EglBase.Context, boolean, YuvConverter, FrameRefMonitor)
	*/
	public static SurfaceTextureHelper create(
	final String threadName, final EglBase.Context sharedContext) {
	return create(threadName, sharedContext, /* alignTimestamps= */ false, new YuvConverter(),
	/frameRefMonitor=/null);
	}

	/**
	* Same as above with yuvConverter set to new YuvConverter.
	*
	* @see #create(String, EglBase.Context, boolean, YuvConverter, FrameRefMonitor)
	*/
	public static SurfaceTextureHelper create(
	final String threadName, final EglBase.Context sharedContext, boolean alignTimestamps) {
	return create(
	threadName, sharedContext, alignTimestamps, new YuvConverter(), /frameRefMonitor=/null);
	}

	/**
	* Create a SurfaceTextureHelper without frame ref monitor.
	*
	* @see #create(String, EglBase.Context, boolean, YuvConverter, FrameRefMonitor)
	*/
	public static SurfaceTextureHelper create(final String threadName,
	final EglBase.Context sharedContext, boolean alignTimestamps, YuvConverter yuvConverter) {
	return create(
	threadName, sharedContext, alignTimestamps, yuvConverter, /frameRefMonitor=/null);
	}

	private final RefCountMonitor textureRefCountMonitor = new RefCountMonitor() {
	@Override
	public void onRetain(TextureBufferImpl textureBuffer) {
	if (frameRefMonitor != null) {
	frameRefMonitor.onRetainBuffer(textureBuffer);
	}
	}

	@Override
	public void onRelease(TextureBufferImpl textureBuffer) {
	if (frameRefMonitor != null) {
	frameRefMonitor.onReleaseBuffer(textureBuffer);
	}
	}

	@Override
	public void onDestroy(TextureBufferImpl textureBuffer) {
	returnTextureFrame();
	if (frameRefMonitor != null) {
	frameRefMonitor.onDestroyBuffer(textureBuffer);
	}
	}
	};

	private final Handler handler;
	private final EglBase eglBase;
	private final SurfaceTexture surfaceTexture;
	private final int oesTextureId;
	private final YuvConverter yuvConverter;
	@Nullable private final TimestampAligner timestampAligner;
	private final FrameRefMonitor frameRefMonitor;

	// These variables are only accessed from the \|handler\| thread.
	@Nullable private VideoSink listener;
	// The possible states of this class.
	private boolean hasPendingTexture;
	private volatile boolean isTextureInUse;
	private boolean isQuitting;
	private int frameRotation;
	private int textureWidth;
	private int textureHeight;
	// \|pendingListener\| is set in setListener() and the runnable is posted to the handler thread.
	// setListener() is not allowed to be called again before stopListening(), so this is thread safe.
	@Nullable private VideoSink pendingListener;
	final Runnable setListenerRunnable = new Runnable() {
	@Override
	public void run() {
	Logging.d(TAG, "Setting listener to " + pendingListener);
	listener = pendingListener;
	pendingListener = null;
	// May have a pending frame from the previous capture session - drop it.
	if (hasPendingTexture) {
	// Calling updateTexImage() is neccessary in order to receive new frames.
	updateTexImage();
	hasPendingTexture = false;
	}
	}
	};

	private SurfaceTextureHelper(Context sharedContext, Handler handler, boolean alignTimestamps,
	YuvConverter yuvConverter, FrameRefMonitor frameRefMonitor) {
	if (handler.getLooper().getThread() != Thread.currentThread()) {
	throw new IllegalStateException("SurfaceTextureHelper must be created on the handler thread");
	}
	this.handler = handler;
	this.timestampAligner = alignTimestamps ? new TimestampAligner() : null;
	this.yuvConverter = yuvConverter;
	this.frameRefMonitor = frameRefMonitor;

	eglBase = EglBase.create(sharedContext, EglBase.CONFIG_PIXEL_BUFFER);
	try {
	// Both these statements have been observed to fail on rare occasions, see BUG=webrtc:5682.
	eglBase.createDummyPbufferSurface();
	eglBase.makeCurrent();
	} catch (RuntimeException e) {
	// Clean up before rethrowing the exception.
	eglBase.release();
	handler.getLooper().quit();
	throw e;
	}

	oesTextureId = GlUtil.generateTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES);
	surfaceTexture = new SurfaceTexture(oesTextureId);
	setOnFrameAvailableListener(surfaceTexture, (SurfaceTexture st) -> {
	if (hasPendingTexture) {
	Logging.d(TAG, "A frame is already pending, dropping frame.");
	}

	hasPendingTexture = true;
	tryDeliverTextureFrame();
	}, handler);
	}

	@TargetApi(21)
	private static void setOnFrameAvailableListener(SurfaceTexture surfaceTexture,
	SurfaceTexture.OnFrameAvailableListener listener, Handler handler) {
	if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
	surfaceTexture.setOnFrameAvailableListener(listener, handler);
	} else {
	// The documentation states that the listener will be called on an arbitrary thread, but in
	// pratice, it is always the thread on which the SurfaceTexture was constructed. There are
	// assertions in place in case this ever changes. For API >= 21, we use the new API to
	// explicitly specify the handler.
	surfaceTexture.setOnFrameAvailableListener(listener);
	}
	}

	/**
	* Start to stream textures to the given \|listener\|. If you need to change listener, you need to
	* call stopListening() first.
	*/
	public void startListening(final VideoSink listener) {
	if (this.listener != null \|\| this.pendingListener != null) {
	throw new IllegalStateException("SurfaceTextureHelper listener has already been set.");
	}
	this.pendingListener = listener;
	handler.post(setListenerRunnable);
	}

	/**
	* Stop listening. The listener set in startListening() is guaranteded to not receive any more
	* onFrame() callbacks after this function returns.
	*/
	public void stopListening() {
	Logging.d(TAG, "stopListening()");
	handler.removeCallbacks(setListenerRunnable);
	ThreadUtils.invokeAtFrontUninterruptibly(handler, () -> {
	listener = null;
	pendingListener = null;
	});
	}

	/**
	* Use this function to set the texture size. Note, do not call setDefaultBufferSize() yourself
	* since this class needs to be aware of the texture size.
	*/
	public void setTextureSize(int textureWidth, int textureHeight) {
	if (textureWidth <= 0) {
	throw new IllegalArgumentException("Texture width must be positive, but was " + textureWidth);
	}
	if (textureHeight <= 0) {
	throw new IllegalArgumentException(
	"Texture height must be positive, but was " + textureHeight);
	}
	surfaceTexture.setDefaultBufferSize(textureWidth, textureHeight);
	handler.post(() -> {
	this.textureWidth = textureWidth;
	this.textureHeight = textureHeight;
	tryDeliverTextureFrame();
	});
	}

	/**
	* Forces a frame to be produced. If no new frame is available, the last frame is sent to the
	* listener again.
	*/
	public void forceFrame() {
	handler.post(() -> {
	hasPendingTexture = true;
	tryDeliverTextureFrame();
	});
	}

	/** Set the rotation of the delivered frames. */
	public void setFrameRotation(int rotation) {
	handler.post(() -> this.frameRotation = rotation);
	}

	/**
	* Retrieve the underlying SurfaceTexture. The SurfaceTexture should be passed in to a video
	* producer such as a camera or decoder.
	*/
	public SurfaceTexture getSurfaceTexture() {
	return surfaceTexture;
	}

	/** Retrieve the handler that calls onFrame(). This handler is valid until dispose() is called. */
	public Handler getHandler() {
	return handler;
	}

	/**
	* This function is called when the texture frame is released. Only one texture frame can be in
	* flight at once, so this function must be called before a new frame is delivered.
	*/
	private void returnTextureFrame() {
	handler.post(() -> {
	isTextureInUse = false;
	if (isQuitting) {
	release();
	} else {
	tryDeliverTextureFrame();
	}
	});
	}

	public boolean isTextureInUse() {
	return isTextureInUse;
	}

	/**
	* Call disconnect() to stop receiving frames. OpenGL resources are released and the handler is
	* stopped when the texture frame has been released. You are guaranteed to not receive any more
	* onFrame() after this function returns.
	*/
	public void dispose() {
	Logging.d(TAG, "dispose()");
	ThreadUtils.invokeAtFrontUninterruptibly(handler, () -> {
	isQuitting = true;
	if (!isTextureInUse) {
	release();
	}
	});
	}

	/**
	* Posts to the correct thread to convert \|textureBuffer\| to I420.
	*
	* @deprecated Use toI420() instead.
	*/
	@Deprecated
	public VideoFrame.I420Buffer textureToYuv(final TextureBuffer textureBuffer) {
	return textureBuffer.toI420();
	}

	private void updateTexImage() {
	// SurfaceTexture.updateTexImage apparently can compete and deadlock with eglSwapBuffers,
	// as observed on Nexus 5. Therefore, synchronize it with the EGL functions.
	// See https://bugs.chromium.org/p/webrtc/issues/detail?id=5702 for more info.
	synchronized (EglBase.lock) {
	surfaceTexture.updateTexImage();
	}
	}

	private void tryDeliverTextureFrame() {
	if (handler.getLooper().getThread() != Thread.currentThread()) {
	throw new IllegalStateException("Wrong thread.");
	}
	if (isQuitting \|\| !hasPendingTexture \|\| isTextureInUse \|\| listener == null) {
	return;
	}
	if (textureWidth == 0 \|\| textureHeight == 0) {
	// Information about the resolution needs to be provided by a call to setTextureSize() before
	// frames are produced.
	Logging.w(TAG, "Texture size has not been set.");
	return;
	}
	isTextureInUse = true;
	hasPendingTexture = false;

	updateTexImage();

	final float[] transformMatrix = new float[16];
	surfaceTexture.getTransformMatrix(transformMatrix);
	long timestampNs = surfaceTexture.getTimestamp();
	if (timestampAligner != null) {
	timestampNs = timestampAligner.translateTimestamp(timestampNs);
	}
	final VideoFrame.TextureBuffer buffer =
	new TextureBufferImpl(textureWidth, textureHeight, TextureBuffer.Type.OES, oesTextureId,
	RendererCommon.convertMatrixToAndroidGraphicsMatrix(transformMatrix), handler,
	yuvConverter, textureRefCountMonitor);
	if (frameRefMonitor != null) {
	frameRefMonitor.onNewBuffer(buffer);
	}
	final VideoFrame frame = new VideoFrame(buffer, frameRotation, timestampNs);
	listener.onFrame(frame);
	frame.release();
	}

	private void release() {
	if (handler.getLooper().getThread() != Thread.currentThread()) {
	throw new IllegalStateException("Wrong thread.");
	}
	if (isTextureInUse \|\| !isQuitting) {
	throw new IllegalStateException("Unexpected release.");
	}
	yuvConverter.release();
	GLES20.glDeleteTextures(1, new int[] {oesTextureId}, 0);
	surfaceTexture.release();
	eglBase.release();
	handler.getLooper().quit();
	if (timestampAligner != null) {
	timestampAligner.dispose();
	}
	}
	}