最近本人对自己的相机项目(https://github.com/CainKernel/CainCamera) 做了优化，使得实时渲染的帧率能够得到明显的提升。在此，本人说说优化的一些思路吧。
1、为什么实时渲染跟onPreviewFrame相关？
其实这个跟实时渲染是没太大关系的，主要的原因是——目前的所有人脸检测的SDK都是通过byte[] 的图像数据来做人脸检测的，而glReadPixels的实现实在是太长了，一般都要100毫秒以上，通过GPU读取图像数据实在是没什么好的办法。也就是说，要使用人脸检测SDK，目前Android平台最好的办法就是通过回调的onPreviewFrame提取图像数据。如果没有人脸检测的需求，实时渲染可以通过onFrameAvailable回调直接更新渲染，效率会更高。由于目前的人脸检测SDK的影响，我们就需要保证onPrevieFrame 的帧率，onPreviewFrame 的帧率高低，直接影响了预览画面是否卡顿，录制出来的视频帧率是否足够。基本上对于相机类应用来说，是最核心的部分。
2、对比市面上的相机
目前市面上的主流美颜类相机，在实时渲染上采取的方案都差不多，大多都是通过自定义SurfaceView来实现的，预览帧率方面则差距比较大，尤其是在MTK的CPU上表现并不一致。至于为什么在MTK的CPU上表现不一致，请参考本人的文章——《关于Android Camera onPreviewFrame 预览回调帧率问题》(http://www.jianshu.com/p/a33b1eabe71c)，在这篇文章上面，采用单HandlerThread 和双HandlerThread 在高通CPU和MTK CPU上的onPreviewFrame帧率的差异，可以大体上猜测出市面上的主流相机的方案。在只做磨皮算法的情况下，主流相机的表现如下:
测试设备信息：
设备名称：红米Note2
CPU： 联发科 Helio X10（MT6795）
测试应用以及帧率如下：
美颜相机——渲染的Texture大小 960 x 540，SurfaceView的帧率 7 ~ 13帧，比较卡：
美颜相机_960x540P.png
FaceU激萌——渲染的Texture大小1280 x 720， SufaceView的帧率15~19帧，偶尔画面不够连贯：
FaceU_1280x720P.png
天天P图——渲染的Texture大小1280 x 720， SurfaceView的帧率13 ~ 19帧，偶尔画面不够连贯：
天天P图_1280x720P.png
无他相机 —— 渲染的Texture大小 1280 x 720， SurfaceView的帧率 17 ~ 19帧，偶尔画面不够连贯：
无他相机_1280x720P.png
测试结论：
从上面可以看到，在关闭所有特效，仅仅开启磨皮算法时，各个应用的帧率表现不一，大多数应用的帧率在红米Note2的表现都没有超过20帧的，底层的BufferQueueProducer产生的帧率也勉强达到20帧。这里有个例外，那就是美颜相机的帧率过低了。根据我之前那篇文章，可以猜测美颜相机是采用了双HandlerThread的方式进行渲染的，一个HandlerThread 用来控制相机的打开关闭等操作，一个HandlerThread用来控制渲染各种特效。因为美颜相机在高通的CPU上的帧率是比较正常的，跟其他的相机帧率都在同一个范围内，而在MTK的CPU上帧率却只有一半左右。大部分相机类的APP在红米Note2上的表现都是偶尔画面不够连贯。这个产生的问题主要还是红米Note2 的CPU 和 GPU确实有点落后了，渲染的效率跟不上。在Nexus 5X 、高通808CPU上，以上的各个应用最高值都是超过20帧的，并且帧率相对比较稳定，画面也并没有出现不连贯的情况。
3、怎么优化？
基于前面测试得到的结论，我们想想如何做渲染的优化？在之前的文章里面我们讨论过单双HandlerThread对MTKCPU的onPreviewFrame帧率的影响，一个HandlerThread控制Camera操作，一个HandlerThread 控制渲染的方案很明显是不行的，onPreviewFrame的帧率过低，无法满足实时性要求的，因此我们把相机的控制逻辑以及渲染逻辑都通过一个HandlerThread线程来进行控制。另外方面，渲染次数的控制。比如在录制视频时，不要重复渲染已经渲染过的特效，可以通过在特效渲染完成后，取出texture 的 id，然后单独做添加水印的渲染过程，此时我们只需要绘制一帧所需要的操作就是渲染特效 + 渲染水印，如果在录制视频时再次绘制渲染特效，则此时绘制一帧所需要的操作就是 渲染特效 + (录制视频)渲染特效 + 渲染水印，这样的话，在录制视频的时候，帧率会明显下降。
4、实现过程
基于上面的思路，我们就可以对实时渲染部分进行优化了。首先放渲染优化的结果：
测试设备信息：
设备名称：红米Note2
CPU： 联发科 Helio X10（MT6795）
测试应用及帧率如下：
CainCamera —— 渲染的Texture大小 1280 x 720，SurfaceView的帧率稳定保证在19帧以上，偶尔画面不够连贯，比市面上的所有相机APP不连贯感要弱很多：
CainCamera_1280x720P.png
优化过程：
为了方便控制和解耦，本人预览实现渲染部分分成了几个部分：
DrawerManager：Activity以及SurfaceView 等调用的管理类，用于控制绘制线程RenderThread和RenderHandler回调
RenderThread： 渲染线程，所有的预览、拍照、录制视频等操作均由RenderThread控制
RenderHandler：渲染线程回调
RenderManager：渲染管理器，渲染实体，用于管理渲染预览还是渲染录制的视频等操作
FilterManager：用于管理不同的滤镜，用于返回一个具体的滤镜或者滤镜组
CameraUtils： Camera控制部分，用于打开关闭相机等操作的封装
接下来将会介绍一下主要的实现过程，具体的实现过程请参考本人的开源相机项目 CainCamera：
https://github.com/CainKernel/CainCamera
4.1、SurfaceView 的实现：
public class CameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback {
private static final String TAG = "CameraSurfaceView";
// 触摸点击默认值，触摸差值小于该值算点击事件
private final static float MAX_TOUCH_SIZE_FOR_CLICK = 15f;
// 小于该时间间隔则表示双击
private final static int MAX_DOUBLE_CLICK_INTERVAL = 200;
// 点击时间有效时间
private final static int MAX_CLICK_INTERVAL = 100;
private float mTouchPreviewX = 0;
private float mTouchPreviewY = 0;
private float mTouchUpX = 0;
private float mTouchUpY = 0;
private final Object mOperation = new Object();
private boolean mTouchWithoutSwipe = false;
private OnTouchScroller mScroller;
private OnClickListener mClickListener;
public CameraSurfaceView(Context context) {
super(context);
init();
}
public CameraSurfaceView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public CameraSurfaceView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
getHolder().addCallback(this);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
DrawerManager.getInstance().surfaceCreated(holder);
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
DrawerManager.getInstance().surfacrChanged(width, height);
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
DrawerManager.getInstance().surfaceDestroyed();
}
private boolean mIsWaitUpEvent = false;
private boolean mIsWaitDoubleClick = false;
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mTouchPreviewX = event.getX();
mTouchPreviewY = event.getY();
mIsWaitUpEvent = true;
postDelayed(mTimerForUpEvent, MAX_CLICK_INTERVAL);
break;
case MotionEvent.ACTION_MOVE:
if (Math.abs(event.getX() - mTouchPreviewX) > MAX_TOUCH_SIZE_FOR_CLICK
|| Math.abs(mTouchPreviewY) > MAX_TOUCH_SIZE_FOR_CLICK) {
mIsWaitUpEvent = false;
removeCallbacks(mTimerForUpEvent);
}
break;
case MotionEvent.ACTION_UP:
mTouchUpX = event.getX();
mTouchUpY = event.getY();
mIsWaitUpEvent = false;
removeCallbacks(mTimerForUpEvent);
if (Math.abs(event.getX() - mTouchPreviewX) < MAX_TOUCH_SIZE_FOR_CLICK
&& Math.abs(event.getY() - mTouchPreviewY) < MAX_TOUCH_SIZE_FOR_CLICK) {
synchronized (mOperation) {
mTouchWithoutSwipe = true;
}
processClickEvent();
synchronized (mOperation) {
mTouchWithoutSwipe = false;
}
} else {
synchronized (mOperation) {
if (!mTouchWithoutSwipe) {
processTouchMovingEvent(event);
}
}
}
break;
case MotionEvent.ACTION_CANCEL:
mIsWaitUpEvent = false;
removeCallbacks(mTimerForUpEvent);
break;
}
return true;
}
/**
* 等待松手
*/
private Runnable mTimerForUpEvent = new Runnable() {
@Override
public void run() {
if (mIsWaitUpEvent) {
mIsWaitUpEvent = false;
} else {
}
}
};
/**
* 等待是否存在第二次点击事件
*/
private Runnable mTimerForSecondClick = new Runnable() {
@Override
public void run() {
if (mIsWaitDoubleClick) {
mIsWaitDoubleClick = false;
if (mClickListener != null) {
mClickListener.onClick(mTouchUpX, mTouchUpY);
}
}
}
};
/**
* 点击事件
*/
private void processClickEvent() {
if (mIsWaitDoubleClick) {
if (mClickListener != null) {
mClickListener.doubleClick(mTouchUpX, mTouchUpY);
}
mIsWaitDoubleClick = false;
removeCallbacks(mTimerForSecondClick);
} else {
mIsWaitDoubleClick = true;
postDelayed(mTimerForSecondClick, MAX_DOUBLE_CLICK_INTERVAL);
}
}
/**
* 触摸滑动事件
* @param event
*/
private void processTouchMovingEvent(MotionEvent event) {
if (Math.abs(event.getX() - mTouchPreviewX)
> Math.abs(event.getY() - mTouchPreviewY) * 1.5) {
if (event.getX() - mTouchPreviewX < 0) {
if (mScroller != null) {
mScroller.swipeBack();
}
} else {
if (mScroller != null) {
mScroller.swipeFrontal();
}
}
} else if (Math.abs(event.getY() - mTouchPreviewY)
> Math.abs(event.getX() - mTouchPreviewX) * 1.5) {
if (event.getY() - mTouchPreviewY < 0) {
if (mScroller != null) {
if (mTouchPreviewX < getWidth() / 2) {
mScroller.swipeUpper(true);
} else {
mScroller.swipeUpper(false);
}
}
} else {
if (mScroller != null) {
if (mTouchPreviewX < getWidth() / 2) {
mScroller.swipeDown(true);
} else {
mScroller.swipeDown(false);
}
}
}
}
}
/**
* 添加滑动回调
* @param scroller
*/
public void addScroller(OnTouchScroller scroller) {
mScroller = scroller;
}
/**
* 滑动监听器
*/
public interface OnTouchScroller {
void swipeBack();
void swipeFrontal();
void swipeUpper(boolean startInLeft);
void swipeDown(boolean startInLeft);
}
/**
* 添加点击事件回调
* @param listener
*/
public void addClickListener(OnClickListener listener) {
mClickListener = listener;
}
/**
* 点击事件监听器
*/
public interface OnClickListener {
void onClick(float x, float y);
void doubleClick(float x, float y);
}
}
以上代码实现了自定义SurfaceView，以及单击、双击操作、左滑、右滑、上滑、下滑等操作。实现这些操作主要是为了方便在预览页面进行左右滑动切换滤镜、上下滑动可以改变相机光照亮度(暂未实现)、单击改变对焦等功能。
DrawerManager 的实现如下：
public class DrawerManager {
private static final String TAG = "DrawerManager";
private static DrawerManager mInstance;
private RenderHandler mRenderHandler;
private RenderThread mRenderThread;
// 操作锁
private final Object mSynOperation = new Object();
public static DrawerManager getInstance() {
if (mInstance == null) {
mInstance = new DrawerManager();
}
return mInstance;
}
private DrawerManager() {
}
public void surfaceCreated(SurfaceHolder holder) {
create();
if (mRenderHandler != null) {
mRenderHandler.sendMessage(mRenderHandler
.obtainMessage(RenderHandler.MSG_SURFACE_CREATED, holder));
}
}
public void surfacrChanged(int width, int height) {
if (mRenderHandler != null) {
mRenderHandler.sendMessage(mRenderHandler
.obtainMessage(RenderHandler.MSG_SURFACE_CHANGED, width, height));
}
startPreview();
}
public void surfaceDestroyed() {
stopPreview();
if (mRenderHandler != null) {
mRenderHandler.sendMessage(mRenderHandler
.obtainMessage(RenderHandler.MSG_SURFACE_DESTROYED));
}
destory();
}
/**
* 创建HandlerThread和Handler
*/
synchronized private void create() {
mRenderThread = new RenderThread("RenderThread");
mRenderThread.start();
mRenderHandler = new RenderHandler(mRenderThread.getLooper(), mRenderThread);
// 绑定Handler
mRenderThread.setRenderHandler(mRenderHandler);
}
/**
* 销毁当前持有的Looper 和 Handler
*/
synchronized private void destory() {
// Handler不存在时，需要销毁当前线程，否则可能会出现重新打开不了的情况
if (mRenderHandler == null) {
if (mRenderThread != null) {
mRenderThread.quitSafely();
try {
mRenderThread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
mRenderThread = null;
}
return;
}
mRenderHandler.sendEmptyMessage(RenderHandler.MSG_DESTROY);
mRenderThread.quitSafely();
try {
mRenderThread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
mRenderThread = null;
mRenderHandler = null;
}
/**
* 开始预览
*/
public void startPreview() {
if (mRenderHandler == null) {
return;
}
synchronized (mSynOperation) {
mRenderHandler.sendMessage(mRenderHandler
.obtainMessage(RenderHandler.MSG_START_PREVIEW));
}
}
/**
* 停止预览
*/
public void stopPreview() {
if (mRenderHandler == null) {
return;
}
synchronized (mSynOperation) {
mRenderHandler.sendMessage(mRenderHandler
.obtainMessage(RenderHandler.MSG_STOP_PREVIEW));
}
}
/**
* 设置触摸区域
* @param rect 已经归整到(-1000, -1000)~(1000, 1000) 的区域
*/
public void setFocusAres(Rect rect) {
if (mRenderHandler == null) {
return;
}
synchronized (mSynOperation) {
mRenderHandler.sendMessage(mRenderHandler
.obtainMessage(RenderHandler.MSG_FOCUS_RECT, rect));
}
}
/**
* 改变Filter类型
*/
public void changeFilterType(FilterType type) {
if (mRenderHandler == null) {
return;
}
synchronized (mSynOperation) {
mRenderHandler.sendMessage(mRenderHandler
.obtainMessage(RenderHandler.MSG_FILTER_TYPE, type));
}
}
/**
* 改变滤镜组类型
* @param type
*/
public void changeFilterGroup(FilterGroupType type) {
if (mRenderHandler == null) {
return;
}
synchronized (mSynOperation) {
mRenderHandler.sendMessage(mRenderHandler
.obtainMessage(RenderHandler.MSG_FILTER_GROUP, type));
}
}
/**
* 切换相机
*/
public void switchCamera() {
if (mRenderHandler == null) {
return;
}
synchronized (mSynOperation) {
mRenderHandler.sendMessage(mRenderHandler
.obtainMessage(RenderHandler.MSG_SWITCH_CAMERA));
}
// 开始预览
startPreview();
}
/**
* 开始录制
*/
public void startRecording() {
if (mRenderHandler == null) {
return;
}
synchronized (mSynOperation) {
mRenderHandler.sendMessage(mRenderHandler
.obtainMessage(RenderHandler.MSG_START_RECORDING));
}
}
/**
* 停止录制
*/
public void stopRecording() {
if (mRenderHandler == null) {
return;
}
synchronized (mSynOperation) {
mRenderHandler.sendEmptyMessage(RenderHandler.MSG_STOP_RECORDING);
}
}
/**
* 拍照
*/
public void takePicture() {
if (mRenderHandler == null) {
return;
}
synchronized (mSynOperation) {
// 发送拍照命令
mRenderHandler.sendMessage(mRenderHandler
.obtainMessage(RenderHandler.MSG_TAKE_PICTURE));
}
}
}
DrawerManager 用来操作渲染线程和回调的，用来控制渲染线程的打开关闭、开始预览、停止预览、改变滤镜、改变滤镜组、切换相机、开始录制、停止录制等功能，主要是给Activity等外界调用的，所有相机相关的操作逻辑、渲染逻辑通过Handler回调控制。
接下来，我们看看RenderThread 的实现：
public class RenderThread extends HandlerThread implements SurfaceTexture.OnFrameAvailableListener,
Camera.PreviewCallback {
private static final String TAG = "RenderThread";
// 操作锁
private final Object mSynOperation = new Object();
// Looping锁
private final Object mSyncIsLooping = new Object();
private boolean isPreviewing = false; // 是否预览状态
private boolean isRecording = false; // 是否录制状态
// EGL共享上下文
private EglCore mEglCore;
// EGLSurface
private WindowSurface mDisplaySurface;
// 录制视频用的EGLSurface
private WindowSurface mRecordWindowSurface;
private VideoEncoderCore mVideoEncoder;
// CameraTexture对应的Id
private int mCameraTextureId;
private SurfaceTexture mCameraTexture;
// 矩阵
private final float[] mMatrix = new float[16];
// 视图宽高
private int mViewWidth, mViewHeight;
// 预览图片大小
private int mImageWidth, mImageHeight;
// 是否处于检测阶段
private boolean isFaceDetecting = false;
// 更新帧的锁
private final Object mSyncFrameNum = new Object();
private final Object mSyncTexture = new Object();
// 可用帧
private int mFrameNum = 0;
// 拍照
private boolean isTakePicture = false;
// 录制比特率
private int mRecordBitrate;
// 录制帧率
private static final int FRAME_RATE = 25;
// 录制质量
private static final int BPP = 4;
// 关键点绘制（调试用）
private FacePointsDrawer mFacePointsDrawer;
// 预览回调缓存，解决previewCallback回调内存抖动问题
private byte[] mPreviewBuffer;
private RenderHandler mRenderHandler;
public RenderThread(String name) {
super(name);
}
public void setRenderHandler(RenderHandler handler) {
mRenderHandler = handler;
}
@Override
public void onFrameAvailable(SurfaceTexture surfaceTexture) {
}
private long time = 0;
@Override
public void onPreviewFrame(final byte[] data, Camera camera) {
addNewFrame();
if (mRenderHandler != null) {
synchronized (mSynOperation) {
if (isPreviewing || isRecording) {
mRenderHandler.sendMessage(mRenderHandler
.obtainMessage(RenderHandler.MSG_PREVIEW_CALLBACK, data));
}
}
}
if (mPreviewBuffer != null) {
camera.addCallbackBuffer(mPreviewBuffer);
}
Log.d("onPreviewFrame", "update time = " + (System.currentTimeMillis() - time));
time = System.currentTimeMillis();
}
void surfaceCreated(SurfaceHolder holder) {
mEglCore = new EglCore(null, EglCore.FLAG_RECORDABLE);
mDisplaySurface = new WindowSurface(mEglCore, holder.getSurface(), false);
mDisplaySurface.makeCurrent();
mCameraTextureId = GlUtil.createTextureOES();
mCameraTexture = new SurfaceTexture(mCameraTextureId);
mCameraTexture.setOnFrameAvailableListener(this);
// 打开相机
CameraUtils.openCamera(CameraUtils.DESIRED_PREVIEW_FPS);
// 设置预览Surface
CameraUtils.setPreviewSurface(mCameraTexture);
calculateImageSize();
// 渲染初始化
RenderManager.getInstance().init();
RenderManager.getInstance().onInputSizeChanged(mImageWidth, mImageHeight);
// 禁用深度测试和背面绘制
GLES30.glDisable(GLES30.GL_DEPTH_TEST);
GLES30.glDisable(GLES30.GL_CULL_FACE);
// 添加预览回调以及回调buffer，用于人脸检测
initPreviewCallback();
// 初始化人脸检测工具
initFaceDetection();
}
void surfaceChanged(int width, int height) {
mViewWidth = width;
mViewHeight = height;
onFilterChanged();
RenderManager.getInstance().adjustViewSize();
RenderManager.getInstance().updateTextureBuffer();
RenderManager.getInstance().onDisplaySizeChanged(mViewWidth, mViewHeight);
// 开始预览
CameraUtils.startPreview();
// 渲染视图变化
RenderManager.getInstance().onDisplaySizeChanged(mViewWidth, mViewHeight);
isPreviewing = true;
}
void surfaceDestoryed() {
isPreviewing = false;
CameraUtils.releaseCamera();
FaceManager.getInstance().destory();
if (mCameraTexture != null) {
mCameraTexture.release();
mCameraTexture = null;
}
if (mDisplaySurface != null) {
mDisplaySurface.release();
mDisplaySurface = null;
}
if (mEglCore != null) {
mEglCore.release();
mEglCore = null;
}
if (mFacePointsDrawer != null) {
mFacePointsDrawer.release();
mFacePointsDrawer = null;
}
RenderManager.getInstance().release();
}
/**
* 初始化预览回调
* 备注：在某些设备上，需要在setPreviewTexture之后，startPreview之前添加回调才能使得onPreviewFrame回调正常
*/
private void initPreviewCallback() {
Size previewSize = CameraUtils.getPreviewSize();
int size = previewSize.getWidth() * previewSize.getHeight() * 3 / 2;
mPreviewBuffer = new byte[size];
CameraUtils.setPreviewCallbackWithBuffer(this, mPreviewBuffer);
}
/**
* 初始化人脸检测工具
*/
private void initFaceDetection() {
FaceManager.getInstance().createHandleThread();
if (ParamsManager.canFaceTrack) {
FaceManager.getInstance().initFaceConfig(mImageWidth, mImageHeight);
FaceManager.getInstance().getFaceDetector().setBackCamera(CameraUtils.getCameraID()
== Camera.CameraInfo.CAMERA_FACING_BACK);
addDetectorCallback();
if (ParamsManager.enableDrawingPoints) {
mFacePointsDrawer = new FacePointsDrawer();
}
}
}
/**
* 预览回调
* @param data
*/
void onPreviewCallback(byte[] data) {
if (isFaceDetecting)
return;
isFaceDetecting = true;
if (ParamsManager.canFaceTrack) {
synchronized (mSyncIsLooping) {
FaceManager.getInstance().faceDetecting(data, mImageHeight, mImageWidth);
}
}
isFaceDetecting = false;
}
/**
* 开始预览
*/
void startPreview() {
isPreviewing = true;
if (mCameraTexture != null) {
RenderManager.getInstance().updateTextureBuffer();
CameraUtils.setPreviewSurface(mCameraTexture);
initPreviewCallback();
CameraUtils.startPreview();
}
}
/**
* 停止预览
*/
void stopPreview() {
isPreviewing = false;
CameraUtils.stopPreview();
}
/**
* 计算imageView 的宽高
*/
private void calculateImageSize() {
Size size = CameraUtils.getPreviewSize();
CameraInfo info = CameraUtils.getCameraInfo();
if (info != null) {
if (info.getOrientation() == 90 || info.getOrientation() == 270) {
mImageWidth = size.getHeight();
mImageHeight = size.getWidth();
} else {
mImageWidth = size.getWidth();
mImageHeight = size.getHeight();
}
}
}
/**
* 设置对焦区域
* @param rect
*/
void setFocusAres(Rect rect) {
CameraUtils.setFocusArea(rect, null);
}
/**
* 滤镜或视图发生变化时调用
*/
private void onFilterChanged() {
RenderManager.getInstance().onFilterChanged();
}
/**
* 更新filter
* @param type Filter类型
*/
void changeFilter(FilterType type) {
RenderManager.getInstance().changeFilter(type);
}
/**
* 切换滤镜组
* @param type
*/
void changeFilterGroup(FilterGroupType type) {
synchronized (mSyncIsLooping) {
RenderManager.getInstance().changeFilterGroup(type);
}
}
/**
* 绘制帧
*/
void drawFrame() {
// 如果存在新的帧，则更新帧
synchronized (mSyncFrameNum) {
synchronized (mSyncTexture) {
if (mCameraTexture != null) {
while (mFrameNum != 0) {
mCameraTexture.updateTexImage();
--mFrameNum;
}
} else {
return;
}
}
}
// 切换渲染上下文
mDisplaySurface.makeCurrent();
mCameraTexture.getTransformMatrix(mMatrix);
RenderManager.getInstance().setTextureTransformMatirx(mMatrix);
// 绘制
draw();
// 拍照状态
if (isTakePicture) {
isTakePicture = false;
File file = new File(ParamsManager.ImagePath + "CainCamera_"
+ System.currentTimeMillis() + ".jpeg");
if (!file.getParentFile().exists()) {
file.getParentFile().mkdirs();
}
try {
mDisplaySurface.saveFrame(file);
} catch (IOException e) {
Log.w(TAG, "saceFrame error: " + e.toString());
}
}
mDisplaySurface.swapBuffers();
// 是否处于录制状态
if (isRecording) {
mRecordWindowSurface.makeCurrent();
mVideoEncoder.drainEncoder(false);
// draw();
RenderManager.getInstance().drawRecordingFrame();
mRecordWindowSurface.setPresentationTime(mCameraTexture.getTimestamp());
mRecordWindowSurface.swapBuffers();
}
}
/**
* 添加检测回调
*/
private void addDetectorCallback() {
FaceManager.getInstance().getFaceDetector()
.addDetectorCallback(new DetectorCallback() {
@Override
public void onTrackingFinish(boolean hasFaces) {
// 如果有人脸并且允许绘制关键点，则添加数据
if (hasFaces) {
if (ParamsManager.enableDrawingPoints && mFacePointsDrawer != null) {
mFacePointsDrawer.addPoints(FaceManager.getInstance()
.getFaceDetector().getFacePoints());
}
} else {
if (ParamsManager.enableDrawingPoints && mFacePointsDrawer != null) {
mFacePointsDrawer.addPoints(null);
}
}
}
});
}
/**
* 绘制图像数据到FBO
*/
private void draw() {
// 绘制
RenderManager.getInstance().drawFrame(mCameraTextureId);
// 是否绘制点
if (ParamsManager.enableDrawingPoints && mFacePointsDrawer != null) {
mFacePointsDrawer.drawPoints();
}
}
/**
* 拍照
*/
void takePicture() {
isTakePicture = true;
}
/**
* 开始录制
*/
void startRecording() {
File file = new File(ParamsManager.VideoPath
+ "CainCamera_" + System.currentTimeMillis() + ".mp4");
if (!file.getParentFile().exists()) {
file.getParentFile().mkdirs();
}
// 计算帧率
mRecordBitrate = mViewWidth * mViewHeight * FRAME_RATE / BPP;
try {
mVideoEncoder = new VideoEncoderCore(mViewWidth, mViewHeight,
mRecordBitrate, file);
} catch (IOException e) {
e.printStackTrace();
}
mRecordWindowSurface = new WindowSurface(mEglCore,
mVideoEncoder.getInputSurface(), true);
isRecording = true;
RenderManager.getInstance().initRecordingFilter();
}
/**
* 停止录制
*/
void stopRecording() {
synchronized (mSyncIsLooping) {
mVideoEncoder.drainEncoder(true);
}
isRecording = false;
RenderManager.getInstance().releaseRecordingFilter();
// 录制完成需要释放资源
if (mVideoEncoder != null) {
mVideoEncoder.release();
mVideoEncoder = null;
}
if (mRecordWindowSurface != null) {
mRecordWindowSurface.release();
mRecordWindowSurface = null;
}
}
/**
* 切换相机
*/
void switchCamera() {
CameraUtils.switchCamera(1 - CameraUtils.getCameraID(), mCameraTexture,
this, mPreviewBuffer);
}
/**
* 添加新的一帧
*/
private void addNewFrame() {
synchronized (mSyncFrameNum) {
if (isPreviewing) {
++mFrameNum;
if (mRenderHandler != null) {
mRenderHandler.removeMessages(RenderHandler.MSG_FRAME);
mRenderHandler.sendMessageAtFrontOfQueue(mRenderHandler
.obtainMessage(RenderHandler.MSG_FRAME));
}
}
}
}
}
RenderThread 通过继承HandlerThread，用于控制相机打开、关闭、切换、预览回调、调用RenderManager渲染特效、渲染录制特效的操作。
RenderManager的实现如下：
public final class RenderManager {
private static final String TAG = "RenderManager";
private static RenderManager mInstance;
private static Object mSyncObject = new Object();
// 相机输入流滤镜
private CameraFilter mCameraFilter;
// 实时滤镜组
private BaseImageFilterGroup mRealTimeFilter;
// 当前的TextureId
private int mCurrentTextureId;
private DisplayFilter mRecordFilter;
// 输入流大小
private int mTextureWidth;
private int mTextureHeight;
// 显示大小
private int mDisplayWidth;
private int mDisplayHeight;
private ScaleType mScaleType = ScaleType.CENTER_CROP;
private FloatBuffer mVertexBuffer;
private FloatBuffer mTextureBuffer;
public static RenderManager getInstance() {
if (mInstance == null) {
mInstance = new RenderManager();
}
return mInstance;
}
private RenderManager() {
}
/**
* 初始化
*/
public void init() {
// 释放之前的滤镜
releaseFilters();
releaseBuffers();
initBuffers();
// 初始化滤镜
initFilters();
}
/**
* 初始化缓冲区
*/
private void initBuffers() {
mVertexBuffer = ByteBuffer
.allocateDirect(TextureRotationUtils.CubeVertices.length * 4)
.order(ByteOrder.nativeOrder())
.asFloatBuffer();
mVertexBuffer.put(TextureRotationUtils.CubeVertices).position(0);
mTextureBuffer = ByteBuffer
.allocateDirect(TextureRotationUtils.getTextureVertices().length * 4)
.order(ByteOrder.nativeOrder())
.asFloatBuffer();
mTextureBuffer.put(TextureRotationUtils.getTextureVertices()).position(0);
}
/**
* 初始化滤镜
*/
private void initFilters() {
mCameraFilter = new CameraFilter();
mRealTimeFilter = FilterManager.getFilterGroup();
}
/**
* 调整由于surface的大小与SurfaceView大小不一致带来的显示问题
*/
public void adjustViewSize() {
float[] textureCoords = null;
float[] vertexCoords = null;
// TODO 这里可以做成镜像翻转的
float[] textureVertices = TextureRotationUtils.getTextureVertices();
float[] vertexVertices = TextureRotationUtils.CubeVertices;
float ratioMax = Math.max((float) mDisplayWidth / mTextureWidth,
(float) mDisplayHeight / mTextureHeight);
// 新的宽高
int imageWidth = Math.round(mTextureWidth * ratioMax);
int imageHeight = Math.round(mTextureHeight * ratioMax);
// 获取视图跟texture的宽高比
float ratioWidth = (float) imageWidth / (float) mDisplayWidth;
float ratioHeight = (float) imageHeight / (float) mDisplayHeight;
if (mScaleType == ScaleType.CENTER_INSIDE) {
vertexCoords = new float[] {
vertexVertices[0] / ratioHeight, vertexVertices[1] / ratioWidth, vertexVertices[2],
vertexVertices[3] / ratioHeight, vertexVertices[4] / ratioWidth, vertexVertices[5],
vertexVertices[6] / ratioHeight, vertexVertices[7] / ratioWidth, vertexVertices[8],
vertexVertices[9] / ratioHeight, vertexVertices[10] / ratioWidth, vertexVertices[11],
};
} else if (mScaleType == ScaleType.CENTER_CROP) {
float distHorizontal = (1 - 1 / ratioWidth) / 2;
float distVertical = (1 - 1 / ratioHeight) / 2;
textureCoords = new float[] {
addDistance(textureVertices[0], distVertical), addDistance(textureVertices[1], distHorizontal),
addDistance(textureVertices[2], distVertical), addDistance(textureVertices[3], distHorizontal),
addDistance(textureVertices[4], distVertical), addDistance(textureVertices[5], distHorizontal),
addDistance(textureVertices[6], distVertical), addDistance(textureVertices[7], distHorizontal),
};
}
if (vertexCoords == null) {
vertexCoords = vertexVertices;
}
if (textureCoords == null) {
textureCoords = textureVertices;
}
// 更新VertexBuffer 和 TextureBuffer
mVertexBuffer.clear();
mVertexBuffer.put(vertexCoords).position(0);
mTextureBuffer.clear();
mTextureBuffer.put(textureCoords).position(0);
}
/**
* 计算距离
* @param coordinate
* @param distance
* @return
*/
private float addDistance(float coordinate, float distance) {
return coordinate == 0.0f ? distance : 1 - distance;
}
/**
* 释放资源
*/
public void release() {
releaseFilters();
releaseBuffers();
}
/**
* 释放Filters资源
*/
private void releaseFilters() {
if (mCameraFilter != null) {
mCameraFilter.release();
mCameraFilter = null;
}
if (mRealTimeFilter != null) {
mRealTimeFilter.release();
mRealTimeFilter = null;
}
}
/**
* 释放缓冲区
*/
private void releaseBuffers() {
if (mVertexBuffer != null) {
mVertexBuffer.clear();
mVertexBuffer = null;
}
if (mTextureBuffer != null) {
mTextureBuffer.clear();
mTextureBuffer = null;
}
}
/**
* 更新TextureBuffer
*/
public void updateTextureBuffer() {
if (mCameraFilter != null) {
mCameraFilter.updateTextureBuffer();
}
}
/**
* 渲染Texture的大小
* @param width
* @param height
*/
public void onInputSizeChanged(int width, int height) {
mTextureWidth = width;
mTextureHeight = height;
if (mCameraFilter != null) {
mCameraFilter.onInputSizeChanged(width, height);
}
if (mRealTimeFilter != null) {
mRealTimeFilter.onInputSizeChanged(width, height);
}
}
/**
* Surface显示的大小
* @param width
* @param height
*/
public void onDisplaySizeChanged(int width, int height) {
mDisplayWidth = width;
mDisplayHeight = height;
cameraFilterChanged();
adjustViewSize();
if (mRealTimeFilter != null) {
mRealTimeFilter.onDisplayChanged(width, height);
}
}
/**
* 更新filter
* @param type Filter类型
*/
public void changeFilter(FilterType type) {
if (mRealTimeFilter != null) {
mRealTimeFilter.changeFilter(type);
}
}
/**
* 切换滤镜组
* @param type
*/
public void changeFilterGroup(FilterGroupType type) {
synchronized (mSyncObject) {
if (mRealTimeFilter != null) {
mRealTimeFilter.release();
}
mRealTimeFilter = FilterManager.getFilterGroup(type);
mRealTimeFilter.onInputSizeChanged(mTextureWidth, mTextureHeight);
mRealTimeFilter.onDisplayChanged(mDisplayWidth, mDisplayHeight);
}
}
/**
* 滤镜或视图发生变化时调用
*/
public void onFilterChanged() {
if (mDisplayWidth != mDisplayHeight) {
mCameraFilter.onDisplayChanged(mDisplayWidth, mDisplayHeight);
}
mCameraFilter.initFramebuffer(mTextureWidth, mTextureHeight);
}
/**
* 设置SurfaceTexture TransformMatrix
* @param matirx
*/
public void setTextureTransformMatirx(float[] matirx) {
if (mCameraFilter != null) {
mCameraFilter.setTextureTransformMatirx(matirx);
}
}
/**
* 绘制渲染
* @param textureId
*/
public void drawFrame(int textureId) {
if (mRealTimeFilter == null) {
mCameraFilter.drawFrame(textureId);
mCurrentTextureId = textureId;
} else {
int id = mCameraFilter.drawFrameBuffer(textureId);
mRealTimeFilter.drawFrame(id, mVertexBuffer, mTextureBuffer);
mCurrentTextureId = mRealTimeFilter.getCurrentTextureId();
}
}
/**
* 滤镜或视图发生变化时调用
*/
private void cameraFilterChanged() {
if (mDisplayWidth != mDisplayHeight) {
mCameraFilter.onDisplayChanged(mDisplayWidth, mDisplayHeight);
}
mCameraFilter.initFramebuffer(mTextureWidth, mTextureHeight);
}
/**
* 初始化录制的Filter
*/
public void initRecordingFilter() {
if (mRecordFilter == null) {
mRecordFilter = new DisplayFilter();
}
mRecordFilter.onInputSizeChanged(mTextureWidth, mTextureHeight);
mRecordFilter.onDisplayChanged(mDisplayWidth, mDisplayHeight);
}
/**
* 释放录制的Filter资源
*/
public void releaseRecordingFilter() {
mRecordFilter.release();
mRecordFilter = null;
}
/**
* 渲染录制的帧
*/
public void drawRecordingFrame() {
mRecordFilter.drawFrame(mCurrentTextureId);
}
}
RenderManager 用于控制渲染实体的，各种特效的渲染都通过RenderManager来控制，以及控制录制视频时需要绘制水印，都通过该类来进行管理。
至此，我们就可以愉快地做实时渲染以及做高效率的磨皮算法啦。
5、暂未实现的功能：
录制视频拆分线程、录音和视频合成功能。截止目前，相机项目的视频录制只接入了视频录制，录音和视频合成功能还没添加进来。本人的思路是通过多线程实现，由于MTK的CPU/驱动问题，onPreviewFrame回调帧率的影响，相机控制和渲染操作是在同一个HandlerThread 线程上实现的，但录音和音视频合成肯定不能在当前的RenderThread上实现，这样就阻塞了渲染过程，渲染核心部分在eglSwapBuffer之后的音视频合成部分并不属于渲染操作逻辑上的，因此可以跨线程来实现，但未知跨线程是否对onPreviewFrame帧率存在影响(主要是MTK CPU/驱动问题)，存疑。