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POPreviewCallback onPreviewFrame does not change data
 

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    <p>I want to do some image processing with images from camera and display it on a SurfaceView but I don't know how to modify the camera frame. I tried to use setPreviewCallbackWithBuffer and onPreviewFrame but they do not work as expected, the frame is not modified.</p> <pre><code>/** A basic Camera preview class */ public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback, Camera.PreviewCallback { private SurfaceHolder mHolder; private Camera mCamera; private byte[] mData; private long prevFrameTick = System.currentTimeMillis(); Canvas mCanvas; public CameraPreview(Context context, Camera camera) { super(context); mCamera = camera; // Install a SurfaceHolder.Callback so we get notified when the // underlying surface is created and destroyed. mHolder = getHolder(); mHolder.addCallback(this); Size previewSize = mCamera.getParameters().getPreviewSize(); mData = new byte[(int) (previewSize.height * previewSize.width * 1.5)]; initBuffer(); // deprecated setting, but required on Android versions prior to 3.0 mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); } private void initBuffer() { mCamera.addCallbackBuffer(mData); mCamera.addCallbackBuffer(mData); mCamera.addCallbackBuffer(mData); mCamera.setPreviewCallbackWithBuffer(this); } public void setCamera(Camera cam) { mCamera = cam; initBuffer(); } public void surfaceCreated(SurfaceHolder holder) { // The Surface has been created, now tell the camera where to draw the // preview. try { mCamera.setPreviewDisplay(holder); initBuffer(); mCamera.startPreview(); } catch (IOException e) { Log.d("APP", "Error setting camera preview: " + e.getMessage()); } } public void surfaceDestroyed(SurfaceHolder holder) { // empty. Take care of releasing the Camera preview in your activity. } public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { // If your preview can change or rotate, take care of those events here. // Make sure to stop the preview before resizing or reformatting it. if (mHolder.getSurface() == null) { // preview surface does not exist return; } // stop preview before making changes try { mCamera.stopPreview(); } catch (Exception e) { // ignore: tried to stop a non-existent preview } // set preview size and make any resize, rotate or // reformatting changes here // start preview with new settings try { mCamera.setPreviewDisplay(mHolder); initBuffer(); mCamera.startPreview(); } catch (Exception e) { Log.d("APP", "Error starting camera preview: " + e.getMessage()); } } public void onPreviewFrame(byte[] data, Camera camera) { // System.arraycopy(data, 0, mData, 0, data.length); Log.e("onPreviewFrame", data.length + " " + (System.currentTimeMillis() - prevFrameTick)); prevFrameTick = System.currentTimeMillis(); mData = new byte[data.length]; mCamera.addCallbackBuffer(mData); } } </code></pre>
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    1. COenhance format, please
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