Files
platform-external-webrtc/webrtc/sdk/android/api/org/webrtc/EglRenderer.java
sakal d15165222f Trigger framelisteners even on frames dropped by the FPS reduction by default.
Modification affects EglRenderer on Android. Moves frame dropping to the
renderer thread. Frame listeners are triggered even when FPS reduction is
active unless applyFpsReduction is set to true.

BUG=webrtc:7149

Review-Url: https://codereview.webrtc.org/2688843002
Cr-Commit-Position: refs/heads/master@{#17206}
2017-03-13 12:11:48 +00:00

707 lines
25 KiB
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.graphics.Bitmap;
import android.graphics.SurfaceTexture;
import android.opengl.GLES20;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.view.Surface;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Locale;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
/**
* Implements org.webrtc.VideoRenderer.Callbacks by displaying the video stream on an EGL Surface.
* This class is intended to be used as a helper class for rendering on SurfaceViews and
* TextureViews.
*/
public class EglRenderer implements VideoRenderer.Callbacks {
private static final String TAG = "EglRenderer";
private static final long LOG_INTERVAL_SEC = 4;
private static final int MAX_SURFACE_CLEAR_COUNT = 3;
public interface FrameListener { void onFrame(Bitmap frame); }
private static class FrameListenerAndParams {
public final FrameListener listener;
public final float scale;
public final RendererCommon.GlDrawer drawer;
public FrameListenerAndParams(
FrameListener listener, float scale, RendererCommon.GlDrawer drawer) {
this.listener = listener;
this.scale = scale;
this.drawer = drawer;
}
}
private class EglSurfaceCreation implements Runnable {
private Object surface;
public synchronized void setSurface(Object surface) {
this.surface = surface;
}
@Override
public synchronized void run() {
if (surface != null && eglBase != null && !eglBase.hasSurface()) {
if (surface instanceof Surface) {
eglBase.createSurface((Surface) surface);
} else if (surface instanceof SurfaceTexture) {
eglBase.createSurface((SurfaceTexture) surface);
} else {
throw new IllegalStateException("Invalid surface: " + surface);
}
eglBase.makeCurrent();
// Necessary for YUV frames with odd width.
GLES20.glPixelStorei(GLES20.GL_UNPACK_ALIGNMENT, 1);
}
}
}
private final String name;
// |renderThreadHandler| is a handler for communicating with |renderThread|, and is synchronized
// on |handlerLock|.
private final Object handlerLock = new Object();
private Handler renderThreadHandler;
private final ArrayList<FrameListenerAndParams> frameListeners = new ArrayList<>();
// Variables for fps reduction.
private final Object fpsReductionLock = new Object();
// Time for when next frame should be rendered.
private long nextFrameTimeNs;
// Minimum duration between frames when fps reduction is active, or -1 if video is completely
// paused.
private long minRenderPeriodNs;
// EGL and GL resources for drawing YUV/OES textures. After initilization, these are only accessed
// from the render thread.
private EglBase eglBase;
private final RendererCommon.YuvUploader yuvUploader = new RendererCommon.YuvUploader();
private RendererCommon.GlDrawer drawer;
// Pending frame to render. Serves as a queue with size 1. Synchronized on |frameLock|.
private final Object frameLock = new Object();
private VideoRenderer.I420Frame pendingFrame;
// These variables are synchronized on |layoutLock|.
private final Object layoutLock = new Object();
private float layoutAspectRatio;
// If true, mirrors the video stream horizontally.
private boolean mirror;
// These variables are synchronized on |statisticsLock|.
private final Object statisticsLock = new Object();
// Total number of video frames received in renderFrame() call.
private int framesReceived;
// Number of video frames dropped by renderFrame() because previous frame has not been rendered
// yet.
private int framesDropped;
// Number of rendered video frames.
private int framesRendered;
// Start time for counting these statistics, or 0 if we haven't started measuring yet.
private long statisticsStartTimeNs;
// Time in ns spent in renderFrameOnRenderThread() function.
private long renderTimeNs;
// Time in ns spent by the render thread in the swapBuffers() function.
private long renderSwapBufferTimeNs;
// Used for bitmap capturing.
private GlTextureFrameBuffer bitmapTextureFramebuffer;
// Runnable for posting frames to render thread.
private final Runnable renderFrameRunnable = new Runnable() {
@Override
public void run() {
renderFrameOnRenderThread();
}
};
private final Runnable logStatisticsRunnable = new Runnable() {
@Override
public void run() {
logStatistics();
synchronized (handlerLock) {
if (renderThreadHandler != null) {
renderThreadHandler.removeCallbacks(logStatisticsRunnable);
renderThreadHandler.postDelayed(
logStatisticsRunnable, TimeUnit.SECONDS.toMillis(LOG_INTERVAL_SEC));
}
}
}
};
private final EglSurfaceCreation eglSurfaceCreationRunnable = new EglSurfaceCreation();
/**
* Standard constructor. The name will be used for the render thread name and included when
* logging. In order to render something, you must first call init() and createEglSurface.
*/
public EglRenderer(String name) {
this.name = name;
}
/**
* Initialize this class, sharing resources with |sharedContext|. The custom |drawer| will be used
* for drawing frames on the EGLSurface. This class is responsible for calling release() on
* |drawer|. It is allowed to call init() to reinitialize the renderer after a previous
* init()/release() cycle.
*/
public void init(final EglBase.Context sharedContext, final int[] configAttributes,
RendererCommon.GlDrawer drawer) {
synchronized (handlerLock) {
if (renderThreadHandler != null) {
throw new IllegalStateException(name + "Already initialized");
}
logD("Initializing EglRenderer");
this.drawer = drawer;
final HandlerThread renderThread = new HandlerThread(name + "EglRenderer");
renderThread.start();
renderThreadHandler = new Handler(renderThread.getLooper());
// Create EGL context on the newly created render thread. It should be possibly to create the
// context on this thread and make it current on the render thread, but this causes failure on
// some Marvel based JB devices. https://bugs.chromium.org/p/webrtc/issues/detail?id=6350.
ThreadUtils.invokeAtFrontUninterruptibly(renderThreadHandler, new Runnable() {
@Override
public void run() {
// If sharedContext is null, then texture frames are disabled. This is typically for old
// devices that might not be fully spec compliant, so force EGL 1.0 since EGL 1.4 has
// caused trouble on some weird devices.
if (sharedContext == null) {
logD("EglBase10.create context");
eglBase = new EglBase10(null /* sharedContext */, configAttributes);
} else {
logD("EglBase.create shared context");
eglBase = EglBase.create(sharedContext, configAttributes);
}
}
});
renderThreadHandler.post(eglSurfaceCreationRunnable);
final long currentTimeNs = System.nanoTime();
resetStatistics(currentTimeNs);
renderThreadHandler.postDelayed(
logStatisticsRunnable, TimeUnit.SECONDS.toMillis(LOG_INTERVAL_SEC));
}
}
public void createEglSurface(Surface surface) {
createEglSurfaceInternal(surface);
}
public void createEglSurface(SurfaceTexture surfaceTexture) {
createEglSurfaceInternal(surfaceTexture);
}
private void createEglSurfaceInternal(Object surface) {
eglSurfaceCreationRunnable.setSurface(surface);
postToRenderThread(eglSurfaceCreationRunnable);
}
/**
* Block until any pending frame is returned and all GL resources released, even if an interrupt
* occurs. If an interrupt occurs during release(), the interrupt flag will be set. This function
* should be called before the Activity is destroyed and the EGLContext is still valid. If you
* don't call this function, the GL resources might leak.
*/
public void release() {
logD("Releasing.");
final CountDownLatch eglCleanupBarrier = new CountDownLatch(1);
synchronized (handlerLock) {
if (renderThreadHandler == null) {
logD("Already released");
return;
}
renderThreadHandler.removeCallbacks(logStatisticsRunnable);
// Release EGL and GL resources on render thread.
renderThreadHandler.postAtFrontOfQueue(new Runnable() {
@Override
public void run() {
if (drawer != null) {
drawer.release();
drawer = null;
}
yuvUploader.release();
if (bitmapTextureFramebuffer != null) {
bitmapTextureFramebuffer.release();
bitmapTextureFramebuffer = null;
}
if (eglBase != null) {
logD("eglBase detach and release.");
eglBase.detachCurrent();
eglBase.release();
eglBase = null;
}
eglCleanupBarrier.countDown();
}
});
final Looper renderLooper = renderThreadHandler.getLooper();
// TODO(magjed): Replace this post() with renderLooper.quitSafely() when API support >= 18.
renderThreadHandler.post(new Runnable() {
@Override
public void run() {
logD("Quitting render thread.");
renderLooper.quit();
}
});
// Don't accept any more frames or messages to the render thread.
renderThreadHandler = null;
}
// Make sure the EGL/GL cleanup posted above is executed.
ThreadUtils.awaitUninterruptibly(eglCleanupBarrier);
synchronized (frameLock) {
if (pendingFrame != null) {
VideoRenderer.renderFrameDone(pendingFrame);
pendingFrame = null;
}
}
logD("Releasing done.");
}
/**
* Reset the statistics logged in logStatistics().
*/
private void resetStatistics(long currentTimeNs) {
synchronized (statisticsLock) {
statisticsStartTimeNs = currentTimeNs;
framesReceived = 0;
framesDropped = 0;
framesRendered = 0;
renderTimeNs = 0;
renderSwapBufferTimeNs = 0;
}
}
public void printStackTrace() {
synchronized (handlerLock) {
final Thread renderThread =
(renderThreadHandler == null) ? null : renderThreadHandler.getLooper().getThread();
if (renderThread != null) {
final StackTraceElement[] renderStackTrace = renderThread.getStackTrace();
if (renderStackTrace.length > 0) {
logD("EglRenderer stack trace:");
for (StackTraceElement traceElem : renderStackTrace) {
logD(traceElem.toString());
}
}
}
}
}
/**
* Set if the video stream should be mirrored or not.
*/
public void setMirror(final boolean mirror) {
logD("setMirror: " + mirror);
synchronized (layoutLock) {
this.mirror = mirror;
}
}
/**
* Set layout aspect ratio. This is used to crop frames when rendering to avoid stretched video.
* Set this to 0 to disable cropping.
*/
public void setLayoutAspectRatio(float layoutAspectRatio) {
logD("setLayoutAspectRatio: " + layoutAspectRatio);
synchronized (layoutLock) {
this.layoutAspectRatio = layoutAspectRatio;
}
}
/**
* Limit render framerate.
*
* @param fps Limit render framerate to this value, or use Float.POSITIVE_INFINITY to disable fps
* reduction.
*/
public void setFpsReduction(float fps) {
logD("setFpsReduction: " + fps);
synchronized (fpsReductionLock) {
final long previousRenderPeriodNs = minRenderPeriodNs;
if (fps <= 0) {
minRenderPeriodNs = Long.MAX_VALUE;
} else {
minRenderPeriodNs = (long) (TimeUnit.SECONDS.toNanos(1) / fps);
}
if (minRenderPeriodNs != previousRenderPeriodNs) {
// Fps reduction changed - reset frame time.
nextFrameTimeNs = System.nanoTime();
}
}
}
public void disableFpsReduction() {
setFpsReduction(Float.POSITIVE_INFINITY /* fps */);
}
public void pauseVideo() {
setFpsReduction(0 /* fps */);
}
/**
* Register a callback to be invoked when a new video frame has been received. This version uses
* the drawer of the EglRenderer that was passed in init.
*
* @param listener The callback to be invoked. The callback will be invoked on the render thread.
* It should be lightweight and must not call removeFrameListener.
* @param scale The scale of the Bitmap passed to the callback, or 0 if no Bitmap is
* required.
*/
public void addFrameListener(final FrameListener listener, final float scale) {
addFrameListener(listener, scale, null);
}
/**
* Register a callback to be invoked when a new video frame has been received.
*
* @param listener The callback to be invoked. The callback will be invoked on the render thread.
* It should be lightweight and must not call removeFrameListener.
* @param scale The scale of the Bitmap passed to the callback, or 0 if no Bitmap is
* required.
* @param drawer Custom drawer to use for this frame listener or null to use the default one.
*/
public void addFrameListener(
final FrameListener listener, final float scale, final RendererCommon.GlDrawer drawerParam) {
postToRenderThread(new Runnable() {
@Override
public void run() {
final RendererCommon.GlDrawer listenerDrawer = drawerParam == null ? drawer : drawerParam;
frameListeners.add(new FrameListenerAndParams(listener, scale, listenerDrawer));
}
});
}
/**
* Remove any pending callback that was added with addFrameListener. If the callback is not in
* the queue, nothing happens. It is ensured that callback won't be called after this method
* returns.
*
* @param runnable The callback to remove.
*/
public void removeFrameListener(final FrameListener listener) {
if (Thread.currentThread() == renderThreadHandler.getLooper().getThread()) {
throw new RuntimeException("removeFrameListener must not be called on the render thread.");
}
final CountDownLatch latch = new CountDownLatch(1);
postToRenderThread(new Runnable() {
@Override
public void run() {
latch.countDown();
final Iterator<FrameListenerAndParams> iter = frameListeners.iterator();
while (iter.hasNext()) {
if (iter.next().listener == listener) {
iter.remove();
}
}
}
});
ThreadUtils.awaitUninterruptibly(latch);
}
// VideoRenderer.Callbacks interface.
@Override
public void renderFrame(VideoRenderer.I420Frame frame) {
synchronized (statisticsLock) {
++framesReceived;
}
final boolean dropOldFrame;
synchronized (handlerLock) {
if (renderThreadHandler == null) {
logD("Dropping frame - Not initialized or already released.");
VideoRenderer.renderFrameDone(frame);
return;
}
synchronized (frameLock) {
dropOldFrame = (pendingFrame != null);
if (dropOldFrame) {
VideoRenderer.renderFrameDone(pendingFrame);
}
pendingFrame = frame;
renderThreadHandler.post(renderFrameRunnable);
}
}
if (dropOldFrame) {
synchronized (statisticsLock) {
++framesDropped;
}
}
}
/**
* Release EGL surface. This function will block until the EGL surface is released.
*/
public void releaseEglSurface(final Runnable completionCallback) {
// Ensure that the render thread is no longer touching the Surface before returning from this
// function.
eglSurfaceCreationRunnable.setSurface(null /* surface */);
synchronized (handlerLock) {
if (renderThreadHandler != null) {
renderThreadHandler.removeCallbacks(eglSurfaceCreationRunnable);
renderThreadHandler.postAtFrontOfQueue(new Runnable() {
@Override
public void run() {
if (eglBase != null) {
eglBase.detachCurrent();
eglBase.releaseSurface();
}
completionCallback.run();
}
});
return;
}
}
completionCallback.run();
}
/**
* Private helper function to post tasks safely.
*/
private void postToRenderThread(Runnable runnable) {
synchronized (handlerLock) {
if (renderThreadHandler != null) {
renderThreadHandler.post(runnable);
}
}
}
private void clearSurfaceOnRenderThread() {
if (eglBase != null && eglBase.hasSurface()) {
logD("clearSurface");
GLES20.glClearColor(0 /* red */, 0 /* green */, 0 /* blue */, 0 /* alpha */);
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
eglBase.swapBuffers();
}
}
/**
* Post a task to clear the TextureView to a transparent uniform color.
*/
public void clearImage() {
synchronized (handlerLock) {
if (renderThreadHandler == null) {
return;
}
renderThreadHandler.postAtFrontOfQueue(new Runnable() {
@Override
public void run() {
clearSurfaceOnRenderThread();
}
});
}
}
/**
* Renders and releases |pendingFrame|.
*/
private void renderFrameOnRenderThread() {
// Fetch and render |pendingFrame|.
final VideoRenderer.I420Frame frame;
synchronized (frameLock) {
if (pendingFrame == null) {
return;
}
frame = pendingFrame;
pendingFrame = null;
}
if (eglBase == null || !eglBase.hasSurface()) {
logD("Dropping frame - No surface");
VideoRenderer.renderFrameDone(frame);
return;
}
// Check if fps reduction is active.
final boolean shouldRenderFrame;
synchronized (fpsReductionLock) {
if (minRenderPeriodNs == Long.MAX_VALUE) {
// Rendering is paused.
shouldRenderFrame = false;
} else if (minRenderPeriodNs <= 0) {
// FPS reduction is disabled.
shouldRenderFrame = true;
} else {
final long currentTimeNs = System.nanoTime();
if (currentTimeNs < nextFrameTimeNs) {
logD("Skipping frame rendering - fps reduction is active.");
shouldRenderFrame = false;
} else {
nextFrameTimeNs += minRenderPeriodNs;
// The time for the next frame should always be in the future.
nextFrameTimeNs = Math.max(nextFrameTimeNs, currentTimeNs);
shouldRenderFrame = true;
}
}
}
final long startTimeNs = System.nanoTime();
final float[] texMatrix =
RendererCommon.rotateTextureMatrix(frame.samplingMatrix, frame.rotationDegree);
final float[] drawMatrix;
// After a surface size change, the EGLSurface might still have a buffer of the old size in the
// pipeline. Querying the EGLSurface will show if the underlying buffer dimensions haven't yet
// changed. Such a buffer will be rendered incorrectly, so flush it with a black frame.
final int drawnFrameWidth;
final int drawnFrameHeight;
synchronized (layoutLock) {
final float[] layoutMatrix;
if (layoutAspectRatio > 0) {
final float frameAspectRatio = frame.rotatedWidth() / (float) frame.rotatedHeight();
layoutMatrix = RendererCommon.getLayoutMatrix(mirror, frameAspectRatio, layoutAspectRatio);
if (frameAspectRatio > layoutAspectRatio) {
drawnFrameWidth = (int) (frame.rotatedHeight() * layoutAspectRatio);
drawnFrameHeight = frame.rotatedHeight();
} else {
drawnFrameWidth = frame.rotatedWidth();
drawnFrameHeight = (int) (frame.rotatedWidth() / layoutAspectRatio);
}
} else {
layoutMatrix =
mirror ? RendererCommon.horizontalFlipMatrix() : RendererCommon.identityMatrix();
drawnFrameWidth = frame.rotatedWidth();
drawnFrameHeight = frame.rotatedHeight();
}
drawMatrix = RendererCommon.multiplyMatrices(texMatrix, layoutMatrix);
}
boolean shouldUploadYuvTextures = false;
if (frame.yuvFrame) {
shouldUploadYuvTextures = shouldRenderFrame;
// Check if there are frame listeners that we want to render a bitmap for regardless of if the
// frame was rendered. This is the case when there are frameListeners with scale != 0f.
if (!shouldUploadYuvTextures) {
for (FrameListenerAndParams listenerAndParams : frameListeners) {
if (listenerAndParams.scale != 0f) {
shouldUploadYuvTextures = true;
break;
}
}
}
}
final int[] yuvTextures = shouldUploadYuvTextures
? yuvUploader.uploadYuvData(frame.width, frame.height, frame.yuvStrides, frame.yuvPlanes)
: null;
if (shouldRenderFrame) {
GLES20.glClearColor(0 /* red */, 0 /* green */, 0 /* blue */, 0 /* alpha */);
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
if (frame.yuvFrame) {
drawer.drawYuv(yuvTextures, drawMatrix, drawnFrameWidth, drawnFrameHeight, 0, 0,
eglBase.surfaceWidth(), eglBase.surfaceHeight());
} else {
drawer.drawOes(frame.textureId, drawMatrix, drawnFrameWidth, drawnFrameHeight, 0, 0,
eglBase.surfaceWidth(), eglBase.surfaceHeight());
}
final long swapBuffersStartTimeNs = System.nanoTime();
eglBase.swapBuffers();
final long currentTimeNs = System.nanoTime();
synchronized (statisticsLock) {
++framesRendered;
renderTimeNs += (currentTimeNs - startTimeNs);
renderSwapBufferTimeNs += (currentTimeNs - swapBuffersStartTimeNs);
}
}
notifyCallbacks(frame, yuvTextures, texMatrix);
VideoRenderer.renderFrameDone(frame);
}
private void notifyCallbacks(
VideoRenderer.I420Frame frame, int[] yuvTextures, float[] texMatrix) {
if (frameListeners.isEmpty())
return;
final float[] bitmapMatrix = RendererCommon.multiplyMatrices(
RendererCommon.multiplyMatrices(texMatrix,
mirror ? RendererCommon.horizontalFlipMatrix() : RendererCommon.identityMatrix()),
RendererCommon.verticalFlipMatrix());
for (FrameListenerAndParams listenerAndParams : frameListeners) {
final int scaledWidth = (int) (listenerAndParams.scale * frame.rotatedWidth());
final int scaledHeight = (int) (listenerAndParams.scale * frame.rotatedHeight());
if (scaledWidth == 0 || scaledHeight == 0) {
listenerAndParams.listener.onFrame(null);
continue;
}
if (bitmapTextureFramebuffer == null) {
bitmapTextureFramebuffer = new GlTextureFrameBuffer(GLES20.GL_RGBA);
}
bitmapTextureFramebuffer.setSize(scaledWidth, scaledHeight);
GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, bitmapTextureFramebuffer.getFrameBufferId());
GLES20.glFramebufferTexture2D(GLES20.GL_FRAMEBUFFER, GLES20.GL_COLOR_ATTACHMENT0,
GLES20.GL_TEXTURE_2D, bitmapTextureFramebuffer.getTextureId(), 0);
GLES20.glClearColor(0 /* red */, 0 /* green */, 0 /* blue */, 0 /* alpha */);
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
if (frame.yuvFrame) {
listenerAndParams.drawer.drawYuv(yuvTextures, bitmapMatrix, frame.rotatedWidth(),
frame.rotatedHeight(), 0 /* viewportX */, 0 /* viewportY */, scaledWidth, scaledHeight);
} else {
listenerAndParams.drawer.drawOes(frame.textureId, bitmapMatrix, frame.rotatedWidth(),
frame.rotatedHeight(), 0 /* viewportX */, 0 /* viewportY */, scaledWidth, scaledHeight);
}
final ByteBuffer bitmapBuffer = ByteBuffer.allocateDirect(scaledWidth * scaledHeight * 4);
GLES20.glViewport(0, 0, scaledWidth, scaledHeight);
GLES20.glReadPixels(
0, 0, scaledWidth, scaledHeight, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, bitmapBuffer);
GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, 0);
GlUtil.checkNoGLES2Error("EglRenderer.notifyCallbacks");
final Bitmap bitmap = Bitmap.createBitmap(scaledWidth, scaledHeight, Bitmap.Config.ARGB_8888);
bitmap.copyPixelsFromBuffer(bitmapBuffer);
listenerAndParams.listener.onFrame(bitmap);
}
frameListeners.clear();
}
private String averageTimeAsString(long sumTimeNs, int count) {
return (count <= 0) ? "NA" : TimeUnit.NANOSECONDS.toMicros(sumTimeNs / count) + " μs";
}
private void logStatistics() {
final long currentTimeNs = System.nanoTime();
synchronized (statisticsLock) {
final long elapsedTimeNs = currentTimeNs - statisticsStartTimeNs;
if (elapsedTimeNs <= 0) {
return;
}
final float renderFps = framesRendered * TimeUnit.SECONDS.toNanos(1) / (float) elapsedTimeNs;
logD("Duration: " + TimeUnit.NANOSECONDS.toMillis(elapsedTimeNs) + " ms."
+ " Frames received: " + framesReceived + "."
+ " Dropped: " + framesDropped + "."
+ " Rendered: " + framesRendered + "."
+ " Render fps: " + String.format(Locale.US, "%.1f", renderFps) + "."
+ " Average render time: " + averageTimeAsString(renderTimeNs, framesRendered) + "."
+ " Average swapBuffer time: "
+ averageTimeAsString(renderSwapBufferTimeNs, framesRendered) + ".");
resetStatistics(currentTimeNs);
}
}
private void logD(String string) {
Logging.d(TAG, name + string);
}
}