思路：

我的实时视频流需要加水印，我的解决思路是：将水印图片转换成YUV格式，在Camera中onPreviewFrame中将获取到的视频流做一个叠加

1：水印转YUV

//从drawble中获取水印图片

Bitmap bmp1 = BitmapFactory.decodeResource(App.getCtx().getResources(), R.drawable.ic_camera );

//缩小图片

final Bitmap bmp=scaleImage(bmp1,40,40);

//转YUV

final byte[] mark=getYUVByBitmap(bmp);

2：叠加

int startY=100;//水印Y轴的位置

int startX=100;//水印X轴的位置

mCamera.setPreviewCallback(new Camera.PreviewCallback() {

@Override

public void onPreviewFrame(byte[] data, Camera camera) {

int j=0;

for(int i=startY; i

for(int c=0;c

//去掉PNG水印的黑边

if(mark[j*bmp.getWidth()+c]!=0x10&&mark[j*bmp.getWidth()+c]!=0x80&&mark[j*bmp.getWidth()+c]!=0xeb){

System.arraycopy(mark,j*bmp.getWidth()+c,data,startX+i*1280+c,1);

}

}

j++;

}

PS:获取图片YUV所需的方法

//缩小图片到制定长宽

public static Bitmap scaleImage(Bitmap bm, int newWidth, int newHeight)

{

if (bm == null)

{

return null;

}

int width = bm.getWidth();

int height = bm.getHeight();

float scaleWidth = ((float) newWidth) / width;

float scaleHeight = ((float) newHeight) / height;

Matrix matrix = new Matrix();

matrix.postScale(scaleWidth, scaleHeight);

Bitmap newbm = Bitmap.createBitmap(bm, 0, 0, width, height, matrix,

true);

if (bm != null & !bm.isRecycled())

{

bm.recycle();

bm = null;

}

return newbm;

}

//图片转YUV

public byte[] getYUVByBitmap(Bitmap bitmap) {

if (bitmap == null) {

return null;

}

int width = bitmap.getWidth();

int height = bitmap.getHeight();

int size = width * height;

int pixels[] = new int[size];

bitmap.getPixels(pixels, 0, width, 0, 0, width, height);

byte[] data = rgb2YCbCr420(pixels, width, height);

return data;

}

public static byte[] rgb2YCbCr420(int[] pixels, int width, int height) {

int len = width * height;

//yuv格式数组大小，y亮度占len长度，u,v各占len/4长度。

byte[] yuv = new byte[len * 3 / 2];

int y, u, v;

for (int i = 0; i < height; i++) {

for (int j = 0; j < width; j++) {

//屏蔽ARGB的透明度值

int rgb = pixels[i * width + j] & 0x00FFFFFF;

//像素的颜色顺序为bgr，移位运算。

int r = rgb & 0xFF;

int g = (rgb >> 8) & 0xFF;

int b = (rgb >> 16) & 0xFF;

//套用公式

y = ((66 * r + 129 * g + 25 * b + 128) >> 8) + 16;

u = ((-38 * r - 74 * g + 112 * b + 128) >> 8) + 128;

v = ((112 * r - 94 * g - 18 * b + 128) >> 8) + 128;

y = y < 16 ? 16 : (y > 255 ? 255 : y);

u = u < 0 ? 0 : (u > 255 ? 255 : u);

v = v < 0 ? 0 : (v > 255 ? 255 : v);

//赋值

yuv[i * width + j] = (byte) y;

yuv[len + (i >> 1) * width + (j & ~1) + 0] = (byte) u;

yuv[len + +(i >> 1) * width + (j & ~1) + 1] = (byte) v;

}

}

return yuv;

}

此水印为黑白色，需要彩色的还需自行将bitmap转YUV