屏幕捕捉

截图

	public static Bitmap getBitmap(Image image) {		int width = image.getWidth();		int height = image.getHeight();		Image.Plane[] planes = image.getPlanes();		ByteBuffer buffer = planes[0].getBuffer();		int pixelStride = planes[0].getPixelStride();		int rowStride = planes[0].getRowStride();		int rowPadding = rowStride - pixelStride * width;		Bitmap bitmap = Bitmap.createBitmap(width + rowPadding / pixelStride,				height, Bitmap.Config.ARGB_8888);		bitmap.copyPixelsFromBuffer(buffer);		bitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height);		image.close();		return bitmap;	}截图服务的主要逻辑代码如下所示：
@TargetApi(Build.VERSION_CODES.LOLLipOP)public class CaptureService extends Service implements FloatClickListener {	private static final String TAG = "CaptureService";	private MediaProjectionManager mMpMgr;	private MediaProjection mMP;	private ImageReader mImageReader;	private String mImagePath, mImageName;	private int mScreenWidth, mScreenHeight, mScreenDensity;	private VirtualDisplay mVirtualDisplay;	private FloatView mFloatView;	@Override	public IBinder onBind(Intent intent) {		return null;	}	@Override	public void onCreate() {		super.onCreate();		mImagePath = Environment.getExternalStoragePublicDirectory(				Environment.DIRECTORY_DOWNLOADS).getAbsolutePath() + "/ScreenShots/";		mMpMgr = Mainapplication.getInstance().getMpMgr();		mScreenWidth = DisplayUtil.getSreenWidth(this);		mScreenHeight = DisplayUtil.getSreenHeight(this);		mScreenDensity = DisplayUtil.getSreenDensityDpi(this);		mImageReader = ImageReader.newInstance(mScreenWidth, mScreenHeight, PixelFormat.RGBA_8888, 2);		if (mFloatView == null) {			mFloatView = new FloatView(MainApplication.getInstance());			mFloatView.setLayout(R.layout.float_capture);		}		mFloatView.setOnFloatListener(this);	}	@Override	public int onStartCommand(Intent intent, int flags, int startId) {		if (mFloatView != null && mFloatView.isShow() == false) {			mFloatView.show();		}		return super.onStartCommand(intent, flags, startId);	}	@Override	public void onFloatClick(View v) {		Toast.makeText(this, "准备截图", Toast.LENGTH_SHORT).show();		mHandler.postDelayed(mStartVirtual, 100); // 准备屏幕		mHandler.postDelayed(mCapture, 500); // 进行截图		mHandler.postDelayed(mStopVirtual, 1000); // 释放屏幕	}		private Handler mHandler = new Handler();	private Runnable mStartVirtual = new Runnable() {		@Override		public void run() {			mFloatView.mContentView.setVisibility(View.INVISIBLE);			if (mMP == null) {				mMP = mMpMgr.getMediaProjection(MainApplication.getInstance().getResultCode(), 						MainApplication.getInstance().getResultIntent());			}			mVirtualDisplay = mMP.createVirtualDisplay("capture_screen", mScreenWidth, mScreenHeight,					mScreenDensity, DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR,					mImageReader.getSurface(), null, null);		}	};	private Runnable mCapture = new Runnable() {		@Override		public void run() {			mImageName = Utils.getNowDateTime() + ".png";			Log.d(TAG, "mImageName=" + mImageName);			Bitmap bitmap = FileUtil.getBitmap(mImageReader.acquireLatestImage());			if (bitmap != null) {				FileUtil.createFile(mImagePath, mImageName);				FileUtil.saveBitmap(mImagePath+mImageName, bitmap, "PNG", 100);				Toast.makeText(CaptureService.this, "截图成功："+mImagePath+mImageName, Toast.LENGTH_SHORT).show();			} else {				Toast.makeText(CaptureService.this, "截图失败：未截到屏幕图片", Toast.LENGTH_SHORT).show();			}		}	};	private Runnable mStopVirtual = new Runnable() {		@Override		public void run() {			mFloatView.mContentView.setVisibility(View.VISIBLE);			if (mVirtualDisplay != null) {				mVirtualDisplay.release();				mVirtualDisplay = null;			}		}	};	@Override	public void onDestroy() {		if (mFloatView != null && mFloatView.isShow() == true) {			mFloatView.close();		}		if (mMP != null) {			mMP.stop();		}		super.onDestroy();	}}
录屏
把用户在屏幕上的操作行为录制成视频，我们称之为录屏。因为视频有多种格式，不同格式的编码过程也不相同，所以录屏的过程比起截图要复杂得多，主要功能点简述如下：1、需要控制何时开始录屏，何时结束录屏；2、设置视频的编码格式，及其对应的编码过程；3、指定视频的常见播放参数，如尺寸、位率、帧率、色彩等等；具体到编码实现上，录屏使用了MediaCodec媒体编码器和MediaMuxer媒体转换器两个工具，通过这两个工具的相互配合，方能完成屏幕录制功能。下面是媒体编码器MediaCodec的主要方法说明：createEncoderByType : 静态函数，根据编码格式构造一个媒体编码器。编码格式通常取值MediaFormat.MIMETYPE_VIDEO_AVC。configure : 设置媒体编码的参数，包括视频格式、视频宽高、视频位率、视频帧率等等。createInputSurface : 创建一个用于输入的表面对象。在实现录屏功能时，这里的表面对象要作为createVirtualDisplay方法的输入参数。start : 开始编码。dequeueOutputBuffer : 给输出缓冲区排队。返回该输出缓冲区的索引位置。getOutputFormat : 获取输出格式。getOutputBuffer : 根据索引位置获取输出缓冲区的数据。releaSEOutputBuffer : 释放指定索引位置的输出缓冲区。stop : 停止编码。release : 释放媒体编码资源。下面是媒体转换器MediaMuxer的主要方法说明：构造函数 : 根据文件路径与文件格式构造一个媒体转换器。文件格式通常取值MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4。addTrack : 把指定格式添加到转换轨道上。返回轨道的索引位置。start : 开始工作。writeSampleData : 把编码转换后的数据写入索引位置的轨道。该方法在MediaCodec的getOutputBuffer方法之后调用。stop : 停止工作。release : 释放媒体转换资源。由于截图和录屏可用于捕捉其它App的画面，为了让录屏App在其它界面上也能响应控制操作，因此要把录屏App的控制条做成悬浮窗的样式，通过悬浮窗按钮完成截图或者录屏功能。有关悬浮窗的说明参见《Android开发笔记（一百一十八）自定义悬浮窗》。录屏服务的主要逻辑代码如下所示：
@TargetApi(Build.VERSION_CODES.LOLLIPOP)public class RecordService extends Service implements FloatClickListener {	private static final String TAG = "RecordService";	private String mVideoPath, mVideoName;	private MediaProjectionManager mMpMgr;	private MediaProjection mMP;	private VirtualDisplay mVirtualDisplay;	private int mScreenWidth, mScreenHeight, mScreenDensity;	private MediaCodec mMediaCodec;	private MediaMuxer mMediaMuxer;	private boolean isRecording = false, isMuxerStarted = false;	private MediaCodec.BufferInfo mBufferInfo = new MediaCodec.BufferInfo();	private int mVideoTrackIndex = -1;	private FloatView mFloatView;	private ImageView iv_record;	@Override	public IBinder onBind(Intent intent) {		return null;	}	@Override	public void onCreate() {		super.onCreate();		mVideoPath = Environment.getExternalStoragePublicDirectory(				Environment.DIRECTORY_DOWNLOADS).getAbsolutePath() + "/ScreenRecords/";		mMpMgr = MainApplication.getInstance().getMpMgr();		mScreenWidth = DisplayUtil.getSreenWidth(this);		mScreenHeight = DisplayUtil.getSreenHeight(this);		mScreenDensity = DisplayUtil.getSreenDensityDpi(this);		if (mFloatView == null) {			mFloatView = new FloatView(MainApplication.getInstance());			mFloatView.setLayout(R.layout.float_record);		}		mFloatView.setOnFloatListener(this);		iv_record = (ImageView) mFloatView.mContentView.findViewById(R.id.iv_record);	}	@Override	public int onStartCommand(Intent intent, int flags, int startId) {		if (mFloatView != null && mFloatView.isShow() == false) {			mFloatView.show();		}		return super.onStartCommand(intent, flags, startId);	}	@Override	public void onFloatClick(View v) {		isRecording = !isRecording;		if (isRecording) {			iv_record.setImageResource(R.drawable.ic_record_pause);			Toast.makeText(RecordService.this, "开始录屏", Toast.LENGTH_SHORT).show();			recordStart();		} else {			iv_record.setImageResource(R.drawable.ic_record_begin);			Toast.makeText(RecordService.this, "结束录屏："+mVideoPath+mVideoName, Toast.LENGTH_SHORT).show();		}	}		private String prepare() {		MediaFormat format = MediaFormat.createVideoFormat(				MediaFormat.MIMETYPE_VIDEO_AVC, mScreenWidth, mScreenHeight); //视频格式与宽高		format.setInteger(MediaFormat.KEY_BIT_RATE, 300*1024*8); //每秒多少位，这里设置每秒300K		format.setInteger(MediaFormat.KEY_FRAME_RATE, 20); //每秒多少帧，每秒20帧则每帧大小15K		format.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface); //设置颜色格式		format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 2); //设置关键帧的间隔		try {			mMediaCodec = MediaCodec.createEncoderByType(MediaFormat.MIMETYPE_VIDEO_AVC);			mMediaCodec.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);			mMediaCodec.start(); //开始视频编码			return null;		} catch (Exception e) {			e.printStackTrace();			return e.getMessage();		}	}	private void recordStart() {		String result = prepare();		if (result != null) {			Toast.makeText(this, "准备录屏发生异常："+result, Toast.LENGTH_SHORT).show();			return;		}		if (mMP == null) {			mMP = mMpMgr.getMediaProjection(MainApplication.getInstance().getResultCode(), 					MainApplication.getInstance().getResultIntent());		}		mVirtualDisplay = mMP.createVirtualDisplay("ScreenRecords", mScreenWidth, mScreenHeight, mScreenDensity, 				DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR, mMediaCodec.createInputSurface(), null, null);		new RecordThread().start();	}	private class RecordThread extends Thread {		@Override		public void run() {			try {				Log.d(TAG, "RecordThread Start");				FileUtil.createDir(mVideoPath);				mVideoName = Utils.getNowDateTime() + ".mp4"; //文件格式为MPEG-4				mMediaMuxer = new MediaMuxer(mVideoPath+mVideoName, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);				while (isRecording) {					int index = mMediaCodec.dequeueOutputBuffer(mBufferInfo, 10000); //返回缓冲区的索引					Log.d(TAG, "缓冲区的索引为" + index);					if (index == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) { //输出格式发生变化						if (isMuxerStarted) {							throw new IllegalStateException("输出格式已经发生变化");						}						MediaFormat newFormat = mMediaCodec.getOutputFormat();						mVideoTrackIndex = mMediaMuxer.addTrack(newFormat);						mMediaMuxer.start();						isMuxerStarted = true;						Log.d(TAG, "新的输出格式是："+newFormat.toString()+"，媒体转换器的轨道索引是"+mVideoTrackIndex);					} else if (index == MediaCodec.INFO_TRY_AGAIN_LATER) { //请求超时						Thread.sleep(50);					} else if (index >= 0) { //正常输出						if (!isMuxerStarted) {							throw new IllegalStateException("媒体转换器尚未添加格式轨道");						}						encodeToVideo(index);						mMediaCodec.releaseOutputBuffer(index, false);					}				}			} catch (Exception e) {				e.printStackTrace();			} finally {				release();			}		}	}	private void encodeToVideo(int index) {		ByteBuffer encoded = mMediaCodec.getOutputBuffer(index);		if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) { //如果不是媒体数据			mBufferInfo.size = 0;		}		if (mBufferInfo.size == 0) { //缓冲区不存在有效数据			encoded = null;		} else {			Log.d(TAG, "缓冲区大小=" + mBufferInfo.size					+ ", 持续时间=" + mBufferInfo.presentationTimeUs					+ ", 偏移=" + mBufferInfo.offset);		}		if (encoded != null) {			encoded.position(mBufferInfo.offset);			encoded.limit(mBufferInfo.offset + mBufferInfo.size);			mMediaMuxer.writeSampleData(mVideoTrackIndex, encoded, mBufferInfo); //写入视频文件		}	}	private void release() {		isRecording = false;		isMuxerStarted = false;		if (mMediaCodec != null) {			mMediaCodec.stop();			mMediaCodec.release();			mMediaCodec = null;		}		if (mVirtualDisplay != null) {			mVirtualDisplay.release();			mVirtualDisplay = null;		}		if (mMediaMuxer != null) {			mMediaMuxer.stop();			mMediaMuxer.release();			mMediaMuxer = null;		}	}	@Override	public void onDestroy() {		release();		if (mFloatView != null && mFloatView.isShow() == true) {			mFloatView.close();		}		if (mMP != null) {			mMP.stop();		}		super.onDestroy();	}}点此查看Android开发笔记的完整目录