我主要活动的Android代码。
这在我的模拟器上工作得非常好但是当我在我的真实设备上运行它时（Alcatel 785 Smart 4 Mini）应用程序崩溃了。
logcat将作为评论提供。
任何帮助或指导都将受到赞赏。
package com.example.viewfinderee368;
import java.io.IOException;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.hardware.Camera;
import android.hardware.Camera.PreviewCallback;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.view.Window;
import android.view.WindowManager;
// ----------------------------------------------------------------------
public class ViewfinderEE368 extends Activity {
private Preview mPreview;
private DrawOnTop mDrawOnTop;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Hide the window title.
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
requestWindowFeature(Window.FEATURE_NO_TITLE);
// Create our Preview view and set it as the content of our activity.
// Create our DrawOnTop view.
mDrawOnTop = new DrawOnTop(this);
mPreview = new Preview(this, mDrawOnTop);
setContentView(mPreview);
addContentView(mDrawOnTop, new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
}
}
//----------------------------------------------------------------------
class DrawOnTop extends View {
Bitmap mBitmap;
Paint mPaintBlack;
Paint mPaintYellow;
Paint mPaintRed;
Paint mPaintGreen;
Paint mPaintBlue;
byte[] mYUVData;
int[] mRGBData;
int mImageWidth, mImageHeight;
int[] mRedHistogram;
int[] mGreenHistogram;
int[] mBlueHistogram;
double[] mBinSquared;
public DrawOnTop(Context context) {
super(context);
mPaintBlack = new Paint();
mPaintBlack.setStyle(Paint.Style.FILL);
mPaintBlack.setColor(Color.BLACK);
mPaintBlack.setTextSize(25);
mPaintYellow = new Paint();
mPaintYellow.setStyle(Paint.Style.FILL);
mPaintYellow.setColor(Color.YELLOW);
mPaintYellow.setTextSize(25);
mPaintRed = new Paint();
mPaintRed.setStyle(Paint.Style.FILL);
mPaintRed.setColor(Color.RED);
mPaintRed.setTextSize(25);
mPaintGreen = new Paint();
mPaintGreen.setStyle(Paint.Style.FILL);
mPaintGreen.setColor(Color.GREEN);
mPaintGreen.setTextSize(25);
mPaintBlue = new Paint();
mPaintBlue.setStyle(Paint.Style.FILL);
mPaintBlue.setColor(Color.BLUE);
mPaintBlue.setTextSize(25);
mBitmap = null;
mYUVData = null;
mRGBData = null;
mRedHistogram = new int[256];
mGreenHistogram = new int[256];
mBlueHistogram = new int[256];
mBinSquared = new double[256];
for (int bin = 0; bin < 256; bin++)
{
mBinSquared[bin] = ((double)bin) * bin;
} // bin
}
@Override
protected void onDraw(Canvas canvas) {
if (mBitmap != null)
{
int canvasWidth = canvas.getWidth();
int canvasHeight = canvas.getHeight();
int newImageWidth = canvasWidth;
int newImageHeight = canvasHeight;
int marginWidth = (canvasWidth - newImageWidth)/2;
// Convert from YUV to RGB
decodeYUV420SP(mRGBData, mYUVData, mImageWidth, mImageHeight);
// Draw bitmap
mBitmap.setPixels(mRGBData, 0, mImageWidth, 0, 0,
mImageWidth, mImageHeight);
Rect src = new Rect(0, 0, mImageWidth, mImageHeight);
Rect dst = new Rect(marginWidth, 0,
canvasWidth-marginWidth, canvasHeight);
canvas.drawBitmap(mBitmap, src, dst, mPaintBlack);
// Draw black borders
canvas.drawRect(0, 0, marginWidth, canvasHeight, mPaintBlack);
canvas.drawRect(canvasWidth - marginWidth, 0,
canvasWidth, canvasHeight, mPaintBlack);
// Calculate histogram
calculateIntensityHistogram(mRGBData, mRedHistogram,
mImageWidth, mImageHeight, 0);
calculateIntensityHistogram(mRGBData, mGreenHistogram,
mImageWidth, mImageHeight, 1);
calculateIntensityHistogram(mRGBData, mBlueHistogram,
mImageWidth, mImageHeight, 2);
// Calculate mean
double imageRedMean = 0, imageGreenMean = 0, imageBlueMean = 0;
double redHistogramSum = 0, greenHistogramSum = 0, blueHistogramSum = 0;
for (int bin = 0; bin < 256; bin++)
{
imageRedMean += mRedHistogram[bin] * bin;
redHistogramSum += mRedHistogram[bin];
imageGreenMean += mGreenHistogram[bin] * bin;
greenHistogramSum += mGreenHistogram[bin];
imageBlueMean += mBlueHistogram[bin] * bin;
blueHistogramSum += mBlueHistogram[bin];
} // bin
imageRedMean /= redHistogramSum;
imageGreenMean /= greenHistogramSum;
imageBlueMean /= blueHistogramSum;
// Calculate second moment
double imageRed2ndMoment = 0, imageGreen2ndMoment = 0, imageBlue2ndMoment = 0;
for (int bin = 0; bin < 256; bin++)
{
imageRed2ndMoment += mRedHistogram[bin] * mBinSquared[bin];
imageGreen2ndMoment += mGreenHistogram[bin] * mBinSquared[bin];
imageBlue2ndMoment += mBlueHistogram[bin] * mBinSquared[bin];
} // bin
imageRed2ndMoment /= redHistogramSum;
imageGreen2ndMoment /= greenHistogramSum;
imageBlue2ndMoment /= blueHistogramSum;
double imageRedStdDev = Math.sqrt( imageRed2ndMoment - imageRedMean*imageRedMean );
double imageGreenStdDev = Math.sqrt( imageGreen2ndMoment - imageGreenMean*imageGreenMean );
double imageBlueStdDev = Math.sqrt( imageBlue2ndMoment - imageBlueMean*imageBlueMean );
// Draw mean
String imageMeanStr = "Mean (R,G,B): " + String.format("%.4g", imageRedMean) + ", " + String.format("%.4g", imageGreenMean) + ", " + String.format("%.4g", imageBlueMean);
canvas.drawText(imageMeanStr, marginWidth+10-1, 30-1, mPaintBlack);
canvas.drawText(imageMeanStr, marginWidth+10+1, 30-1, mPaintBlack);
canvas.drawText(imageMeanStr, marginWidth+10+1, 30+1, mPaintBlack);
canvas.drawText(imageMeanStr, marginWidth+10-1, 30+1, mPaintBlack);
canvas.drawText(imageMeanStr, marginWidth+10, 30, mPaintYellow);
// Draw standard deviation
String imageStdDevStr = "Std Dev (R,G,B): " + String.format("%.4g", imageRedStdDev) + ", " + String.format("%.4g", imageGreenStdDev) + ", " + String.format("%.4g", imageBlueStdDev);
canvas.drawText(imageStdDevStr, marginWidth+10-1, 60-1, mPaintBlack);
canvas.drawText(imageStdDevStr, marginWidth+10+1, 60-1, mPaintBlack);
canvas.drawText(imageStdDevStr, marginWidth+10+1, 60+1, mPaintBlack);
canvas.drawText(imageStdDevStr, marginWidth+10-1, 60+1, mPaintBlack);
canvas.drawText(imageStdDevStr, marginWidth+10, 60, mPaintYellow);
// Draw red intensity histogram
float barMaxHeight = 3000;
float barWidth = ((float)newImageWidth) / 256;
float barMarginHeight = 2;
RectF barRect = new RectF();
barRect.bottom = canvasHeight - 200;
barRect.left = marginWidth;
barRect.right = barRect.left + barWidth;
for (int bin = 0; bin < 256; bin++)
{
float prob = (float)mRedHistogram[bin] / (float)redHistogramSum;
barRect.top = barRect.bottom -
Math.min(80,prob*barMaxHeight) - barMarginHeight;
canvas.drawRect(barRect, mPaintBlack);
barRect.top += barMarginHeight;
canvas.drawRect(barRect, mPaintRed);
barRect.left += barWidth;
barRect.right += barWidth;
} // bin
// Draw green intensity histogram
barRect.bottom = canvasHeight - 100;
barRect.left = marginWidth;
barRect.right = barRect.left + barWidth;
for (int bin = 0; bin < 256; bin++)
{
barRect.top = barRect.bottom - Math.min(80, ((float)mGreenHistogram[bin])/((float)greenHistogramSum) * barMaxHeight) - barMarginHeight;
canvas.drawRect(barRect, mPaintBlack);
barRect.top += barMarginHeight;
canvas.drawRect(barRect, mPaintGreen);
barRect.left += barWidth;
barRect.right += barWidth;
} // bin
// Draw blue intensity histogram
barRect.bottom = canvasHeight;
barRect.left = marginWidth;
barRect.right = barRect.left + barWidth;
for (int bin = 0; bin < 256; bin++)
{
barRect.top = barRect.bottom - Math.min(80, ((float)mBlueHistogram[bin])/((float)blueHistogramSum) * barMaxHeight) - barMarginHeight;
canvas.drawRect(barRect, mPaintBlack);
barRect.top += barMarginHeight;
canvas.drawRect(barRect, mPaintBlue);
barRect.left += barWidth;
barRect.right += barWidth;
} // bin
} // end if statement
super.onDraw(canvas);
} // end onDraw method
static public void decodeYUV420SP(int[] rgb, byte[] yuv420sp, int width, int height) {
final int frameSize = width * height;
for (int j = 0, yp = 0; j < height; j++) {
int uvp = frameSize + (j >> 1) * width, u = 0, v = 0;
for (int i = 0; i < width; i++, yp++) {
int y = (0xff & ((int) yuv420sp[yp])) - 16;
if (y < 0) y = 0;
if ((i & 1) == 0) {
v = (0xff & yuv420sp[uvp++]) - 128;
u = (0xff & yuv420sp[uvp++]) - 128;
}
int y1192 = 1192 * y;
int r = (y1192 + 1634 * v);
int g = (y1192 - 833 * v - 400 * u);
int b = (y1192 + 2066 * u);
if (r < 0) r = 0; else if (r > 262143) r = 262143;
if (g < 0) g = 0; else if (g > 262143) g = 262143;
if (b < 0) b = 0; else if (b > 262143) b = 262143;
rgb[yp] = 0xff000000 | ((r << 6) & 0xff0000) | ((g >> 2) & 0xff00) | ((b >> 10) & 0xff);
}
}
}
static public void decodeYUV420SPGrayscale(int[] rgb, byte[] yuv420sp, int width, int height)
{
final int frameSize = width * height;
for (int pix = 0; pix < frameSize; pix++)
{
int pixVal = (0xff & ((int) yuv420sp[pix])) - 16;
if (pixVal < 0) pixVal = 0;
if (pixVal > 255) pixVal = 255;
rgb[pix] = 0xff000000 | (pixVal << 16) | (pixVal << 8) | pixVal;
} // pix
}
static public void calculateIntensityHistogram(int[] rgb, int[] histogram, int width, int height, int component)
{
for (int bin = 0; bin < 256; bin++)
{
histogram[bin] = 0;
} // bin
if (component == 0) // red
{
for (int pix = 0; pix < width*height; pix += 3)
{
int pixVal = (rgb[pix] >> 16) & 0xff;
histogram[ pixVal ]++;
} // pix
}
else if (component == 1) // green
{
for (int pix = 0; pix < width*height; pix += 3)
{
int pixVal = (rgb[pix] >> 8) & 0xff;
histogram[ pixVal ]++;
} // pix
}
else // blue
{
for (int pix = 0; pix < width*height; pix += 3)
{
int pixVal = rgb[pix] & 0xff;
histogram[ pixVal ]++;
} // pix
}
}
}
// ----------------------------------------------------------------------
class Preview extends SurfaceView implements SurfaceHolder.Callback {
SurfaceHolder mHolder;
Camera mCamera;
DrawOnTop mDrawOnTop;
boolean mFinished;
Preview(Context context, DrawOnTop drawOnTop) {
super(context);
mDrawOnTop = drawOnTop;
mFinished = false;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
mCamera = Camera.open();
try {
mCamera.setPreviewDisplay(holder);
// Preview callback used whenever new viewfinder frame is available
mCamera.setPreviewCallback(new PreviewCallback() {
public void onPreviewFrame(byte[] data, Camera camera)
{
if ( (mDrawOnTop == null) || mFinished )
return;
if (mDrawOnTop.mBitmap == null)
{
// Initialize the draw-on-top companion
Camera.Parameters params = camera.getParameters();
mDrawOnTop.mImageWidth = params.getPreviewSize().width;
mDrawOnTop.mImageHeight = params.getPreviewSize().height;
mDrawOnTop.mBitmap = Bitmap.createBitmap(mDrawOnTop.mImageWidth,
mDrawOnTop.mImageHeight, Bitmap.Config.RGB_565);
mDrawOnTop.mRGBData = new int[mDrawOnTop.mImageWidth * mDrawOnTop.mImageHeight];
mDrawOnTop.mYUVData = new byte[data.length];
}
// Pass YUV data to draw-on-top companion
System.arraycopy(data, 0, mDrawOnTop.mYUVData, 0, data.length);
mDrawOnTop.invalidate();
}
});
}
catch (IOException exception) {
mCamera.release();
mCamera = null;
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
// Because the CameraDevice object is not a shared resource, it's very
// important to release it when the activity is paused.
mFinished = true;
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
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.
Camera.Parameters parameters = mCamera.getParameters();
parameters.setPreviewSize(320, 240);
parameters.setPreviewFrameRate(15);
parameters.setSceneMode(Camera.Parameters.SCENE_MODE_NIGHT);
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
mCamera.setParameters(parameters);
mCamera.startPreview();
}
}
答案 0 :(得分：1)
以下序列中的某些行与您的设备功能不匹配：
parameters.setPreviewSize(320, 240);
parameters.setPreviewFrameRate(15);
parameters.setSceneMode(Camera.Parameters.SCENE_MODE_NIGHT);
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
通常，logcat中会有指示 - 不是应用程序日志的一部分，而是控制摄像机的系统进程。
即使您在那里找不到提示，也可以通过逐行检查行来消除问题（例外情况不是在您操纵Camera.Parameters时发生，而是在您使用非法值调用mCamera.setParameters()时某处。
您可以检查从mCamera.getParameters()收到的参数，了解支持的预览尺寸，帧速率，对焦模式和场景。