在android中,将videostream预览到视图上

我想将android相机的相机预览stream到视图上。 其意图是事后添加各种东西到视图中,使用onDraw()。 我不需要随时捕捉图像。 它不一定是每秒最高质量或最大数量的帧。 有没有人有一个想法如何做到这一点?

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添加到您的XML:

<SurfaceView android:id="@+id/camerapreview" android:layout_width="wrap_content" android:layout_height="wrap_content" /> 

进入您的活动课程:

 private Preview mPreview; Camera mCamera; int numberOfCameras; int cameraCurrentlyLocked; int defaultCameraId; 

的onCreate-方法:

 mPreview = new Preview(this); setContentView(mPreview); mPreview.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { mCamera.autoFocus(null); } }); 

 @Override protected void onPause() { super.onPause(); // Because the Camera object is a shared resource, it's very // important to release it when the activity is paused. if (mCamera != null) { mPreview.setCamera(null); mCamera.release(); mCamera = null; } } 

 @Override protected void onResume() { super.onResume(); // Open the default ie the first rear facing camera. mCamera = Camera.open(); cameraCurrentlyLocked = defaultCameraId; mPreview.setCamera(mCamera); } 

和预览级别:

 public class Preview extends ViewGroup implements SurfaceHolder.Callback { private final String TAG = "Preview"; SurfaceView mSurfaceView; SurfaceHolder mHolder; Size mPreviewSize; List<Size> mSupportedPreviewSizes; Camera mCamera; public Preview(Context context) { super(context); mSurfaceView = new SurfaceView(context); addView(mSurfaceView); // Install a SurfaceHolder.Callback so we get notified when the // underlying surface is created and destroyed. mHolder = mSurfaceView.getHolder(); mHolder.addCallback(this); mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } public void setCamera(Camera camera) { mCamera = camera; if (mCamera != null) { mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes(); requestLayout(); } } public void switchCamera(Camera camera) { setCamera(camera); try { camera.setPreviewDisplay(mHolder); } catch (IOException exception) { Log.e(TAG, "IOException caused by setPreviewDisplay()", exception); } Camera.Parameters parameters = camera.getParameters(); parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height); requestLayout(); camera.setParameters(parameters); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { // We purposely disregard child measurements because act as a // wrapper to a SurfaceView that centers the camera preview instead // of stretching it. final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec); final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec); setMeasuredDimension(width, height); if (mSupportedPreviewSizes != null) { mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height); } } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { if (changed && getChildCount() > 0) { final View child = getChildAt(0); final int width = r - l; final int height = b - t; int previewWidth = width; int previewHeight = height; if (mPreviewSize != null) { previewWidth = mPreviewSize.width; previewHeight = mPreviewSize.height; } // Center the child SurfaceView within the parent. if (width * previewHeight > height * previewWidth) { final int scaledChildWidth = previewWidth * height / previewHeight; child.layout((width - scaledChildWidth) / 2, 0, (width + scaledChildWidth) / 2, height); } else { final int scaledChildHeight = previewHeight * width / previewWidth; child.layout(0, (height - scaledChildHeight) / 2, width, (height + scaledChildHeight) / 2); } } } public void surfaceCreated(SurfaceHolder holder) { // The Surface has been created, acquire the camera and tell it where // to draw. try { if (mCamera != null) { mCamera.setPreviewDisplay(holder); } } catch (IOException exception) { Log.e(TAG, "IOException caused by setPreviewDisplay()", exception); } } public void surfaceDestroyed(SurfaceHolder holder) { // Surface will be destroyed when we return, so stop the preview. if (mCamera != null) { mCamera.stopPreview(); } } private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) { final double ASPECT_TOLERANCE = 0.1; double targetRatio = (double) w / h; if (sizes == null) return null; Size optimalSize = null; double minDiff = Double.MAX_VALUE; int targetHeight = h; // Try to find an size match aspect ratio and size for (Size size : sizes) { double ratio = (double) size.width / size.height; if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue; if (Math.abs(size.height - targetHeight) < minDiff) { optimalSize = size; minDiff = Math.abs(size.height - targetHeight); } } // Cannot find the one match the aspect ratio, ignore the requirement if (optimalSize == null) { minDiff = Double.MAX_VALUE; for (Size size : sizes) { if (Math.abs(size.height - targetHeight) < minDiff) { optimalSize = size; minDiff = Math.abs(size.height - targetHeight); } } } return optimalSize; } public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { // Now that the size is known, set up the camera parameters and begin // the preview. if(mCamera != null){ Camera.Parameters parameters = mCamera.getParameters(); parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height); requestLayout(); mCamera.setParameters(parameters); mCamera.startPreview(); } } }