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我試圖實時保存相機預覽圖像，我的目標是保存至少1fps從預覽躺在表面視圖。 我卡在這個Android保存實時相機預覽圖像
mCamera.setPreviewCallbackWithBuffer(new Camera.PreviewCallback() {
private long timestamp=0;
public synchronized void onPreviewFrame(byte[] data, Camera camera) {
Log.v("CameraTest","Time Gap = "+(System.currentTimeMillis()-timestamp));
timestamp=System.currentTimeMillis();
try{
FileOutputStream out;
try {
Bitmap bmp=BitmapFactory.decodeByteArray(data,0,data.length);
out = new FileOutputStream("/mnt/sdcard/data/pippo.png");
bmp.compress(Bitmap.CompressFormat.PNG, 90, out);
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
camera.addCallbackBuffer(data);
}catch (Exception e) {
Log.e("CameraTest", "addCallbackBuffer error");
return;
}
return;
}
});
我想，在字節數組中
public synchronized void onPreviewFrame(byte[] data, Camera camera)
通過包含原始數據圖像，所以我試圖將其轉換爲位圖，保存在SD卡。 我的問題是：
- 這是爲了實現我的目標而休業的正確途徑？
- 我在日誌中得到這個錯誤SkImageDecoder :: Factory返回null我想它是在位圖轉換相關的，是不是？
歡迎任何建議。 謝謝
到這裏的全部代碼：
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.ImageFormat;
import android.hardware.Camera;
import android.hardware.Camera.ErrorCallback;
import android.hardware.Camera.Size;
import android.os.Bundle;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.SurfaceHolder.Callback;
public class Demo extends Activity {
SurfaceView mVideoCaptureView;
private Camera mCamera;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mVideoCaptureView = (SurfaceView) findViewById(R.id.video_capture_surface);
SurfaceHolder videoCaptureViewHolder = mVideoCaptureView.getHolder();
videoCaptureViewHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
videoCaptureViewHolder.addCallback(new Callback() {
public void surfaceDestroyed(SurfaceHolder holder) {
}
public void surfaceCreated(SurfaceHolder holder) {
startVideo();
}
public void surfaceChanged(SurfaceHolder holder, int format,
int width, int height) {
}
});
}
private void startVideo() {
SurfaceHolder videoCaptureViewHolder = null;
try {
mCamera = Camera.open();
} catch (RuntimeException e) {
Log.e("CameraTest", "Camera Open filed");
return;
}
mCamera.setErrorCallback(new ErrorCallback() {
public void onError(int error, Camera camera) {
}
});
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewFrameRate(30);
parameters.setPreviewFpsRange(15000,30000);
List<int[]> supportedPreviewFps=parameters.getSupportedPreviewFpsRange();
Iterator<int[]> supportedPreviewFpsIterator=supportedPreviewFps.iterator();
while(supportedPreviewFpsIterator.hasNext()){
int[] tmpRate=supportedPreviewFpsIterator.next();
StringBuffer sb=new StringBuffer();
sb.append("supportedPreviewRate: ");
for(int i=tmpRate.length,j=0;j<i;j++){
sb.append(tmpRate[j]+", ");
}
Log.v("CameraTest",sb.toString());
}
List<Size> supportedPreviewSizes=parameters.getSupportedPreviewSizes();
Iterator<Size> supportedPreviewSizesIterator=supportedPreviewSizes.iterator();
while(supportedPreviewSizesIterator.hasNext()){
Size tmpSize=supportedPreviewSizesIterator.next();
Log.v("CameraTest","supportedPreviewSize.width = "+tmpSize.width+"supportedPreviewSize.height = "+tmpSize.height);
}
mCamera.setParameters(parameters);
if (null != mVideoCaptureView)
videoCaptureViewHolder = mVideoCaptureView.getHolder();
try {
mCamera.setPreviewDisplay(videoCaptureViewHolder);
} catch (Throwable t) {
}
Log.v("CameraTest","Camera PreviewFrameRate = "+mCamera.getParameters().getPreviewFrameRate());
Size previewSize=mCamera.getParameters().getPreviewSize();
int dataBufferSize=(int)(previewSize.height*previewSize.width*
(ImageFormat.getBitsPerPixel(mCamera.getParameters().getPreviewFormat())/8.0));
mCamera.addCallbackBuffer(new byte[dataBufferSize]);
mCamera.addCallbackBuffer(new byte[dataBufferSize]);
mCamera.addCallbackBuffer(new byte[dataBufferSize]);
mCamera.setPreviewCallbackWithBuffer(new Camera.PreviewCallback() {
private long timestamp=0;
public synchronized void onPreviewFrame(byte[] data, Camera camera) {
Log.v("CameraTest","Time Gap = "+(System.currentTimeMillis()-timestamp));
timestamp=System.currentTimeMillis();
try{
FileOutputStream out;
try {
Bitmap bmp=BitmapFactory.decodeByteArray(data,0,data.length);
out = new FileOutputStream("/mnt/sdcard/data/pippo.png");
bmp.compress(Bitmap.CompressFormat.PNG, 90, out);
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
camera.addCallbackBuffer(data);
}catch (Exception e) {
Log.e("CameraTest", "addCallbackBuffer error");
return;
}
return;
}
});
try {
mCamera.startPreview();
} catch (Throwable e) {
mCamera.release();
mCamera = null;
return;
}
}
private void stopVideo() {
if(null==mCamera)
return;
try {
mCamera.stopPreview();
mCamera.setPreviewDisplay(null);
mCamera.setPreviewCallbackWithBuffer(null);
mCamera.release();
} catch (IOException e) {
e.printStackTrace();
return;
}
mCamera = null;
}
public void finish(){
stopVideo();
super.finish();
};
}