Camera - dump 预览帧数据处理(二)

        针对GPU框架opengl渲染的数据，我们只能从GLSurfaceView通过glReadPixels获取预览数据，转化为RGBA格式再dump下来，这个过程不同于dump从底层传入的YUV预览帧数据，以下就是dump GLSurfaceView的详细过程。

一、dump GPU框架渲染数据

glReadPixels方法

    if(mCount%30 == 0)
    {
            //创建byte[]数组获取GPU渲染数据
            byte[] Data = new byte[mOutputWidth * mOutputHeight * 4];
            ByteBuffer buf = ByteBuffer.wrap(Data);
            buf.order(ByteOrder.LITTLE_ENDIAN);

            //通过glReadPixels方法获取GLSurfaceView内容
            GLES20.glReadPixels(0, 0, mOutputWidth, mOutputHeight, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, buf);

            //saveByteToFile(Data, "process");

            Bitmap bmp = setBitmapPixel(null, mOutputWidth, mOutputHeight,  Data);
            saveRGBAtoPNGFile(bmp);
        }

保存RGBA数据为YUV格式

public void saveByteToFile(byte[] data, String path) {
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd-hh-mm-ss");
        String date = sDateFormat.format(new java.util.Date());

        File mediaStorageDir = mActivity.getAndroidContext().getExternalFilesDir("DCIM");
        File d = new File(mediaStorageDir, path);

        //File d = new File("/storage/emulated/0/bitmap/");
        File f = new File(d, date + ".yuv");

        if (!d.exists()) {
            d.mkdirs();
        }

        if (f.exists()) {
            f.delete();
        }

        try {
            FileOutputStream out = new FileOutputStream(f);
            out.write(data);
            out.flush();
            out.close();
        } catch (IOException e) {
            Log.e(TAG, "CameraSaveBitmap saveBitmapToFileException:" + f.getAbsolutePath() + " Exception");
            e.printStackTrace();
        }
    }

保存RGBA数据为PNG格式

1.将原始数组转为RGBA数据格式，且byte转为bitmap数据格式

import android.graphics.Color;
import android.graphics.Bitmap.Config;

public static Bitmap setBitmapPixel(Context context, int width, int height, byte[] data) {
        Bitmap bitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);
        int mBitmapWidth = bitmap.getWidth();
        int mBitmapHeight = bitmap.getHeight();

        for (int i = 0; i < mBitmapHeight; i++) {
            for (int j = 0; j < mBitmapWidth; j++) {
                int index = (i * mBitmapWidth + j) * 4;
                int alpha = data[index + 3] & 0xff;
                int r = data[index] & 0xff;
                int g = data[index + 1] & 0xff;
                int b = data[index + 2] & 0xff;
                bitmap.setPixel(j, i, Color.argb(alpha, r, g, b));
            }
        }
        return bitmap;
    }

 2.将bitmap数据直接png保存

    public void saveRGBAtoPNGFile(Bitmap bmp) {
        String path ="wsj_dump.png";
        File f = new File("/data/local/tmp/anc/", path);
        if (f.exists()) {
                f.delete();
        }
        try {
            Log.e(TAG,"FileOutputStream");
            FileOutputStream out = new FileOutputStream(f);
            bmp.compress(Bitmap.CompressFormat.PNG, 100, out);
            Log.e(TAG,"compress");
            out.flush();
            out.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

public void saveBitmaptoFile(Bitmap bmp, String path) {
        SimpleDateFormat sDateFormat = new SimpleDateFormat("yyyy-MM-dd-hh-mm-ss");
        String date = sDateFormat.format(new java.util.Date());

        File mediaStorageDir = mActivity.getAndroidContext().getExternalFilesDir("DCIM");
        File d = new File(mediaStorageDir, path);

        if (!d.exists()) {
            d.mkdirs();
        }

        File f = new File(d, date + ".png");

        if (f.exists()) {
            f.delete();
        }

        try {
            FileOutputStream out = new FileOutputStream(f);
            bmp.compress(Bitmap.CompressFormat.PNG, 100, out);
            Log.e(TAG,"compress");
            out.flush();
            out.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

 文件保存路径为：

/data/media/0/Android/data/com.android.camera2/files/DCIM/process

另：可读写路径获取

相关代码如下：

public static final String DCIM =
                                            
      Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM).toString();

public static final String DIRECTORY = DCIM + "/Camera";
public static final File DIRECTORY_FILE = new File(DIRECTORY);

CameraUtil.saveBitmapToFile(defaultbitmap, getModuleCoverPicturePath());

最后存储的相关路径为:

data/user/0/com.android.camera2/files

总结：

        dump数据除上述俩种方法外，还有在HAL层dump各个节点数据的方法，这个在后续会进行详细讲解，通过dump帧数据的方法可以让我们准确把握传入算法各个节点的帧的差异，可基于此进行各种不同情况的处理与问题解决。