Android NV21与Bitmap相互转换 可实时添加水印

获取相机回调数据

        @Override
        public void onPreviewFrame(byte[] data, Camera camera) {
			//这里的data便是原始视频数据
		}

将视频数据转化为bitmap

    public Bitmap nv21ToBitmap(byte[] nv21, int width, int height){
        if (yuvType == null){
            yuvType = new Type.Builder(renderScript, Element.U8(renderScript)).setX(nv21.length);
            in = Allocation.createTyped(renderScript, yuvType.create(), Allocation.USAGE_SCRIPT);
            rgbaType = new Type.Builder(renderScript, Element.RGBA_8888(renderScript)).setX(width).setY(height);
            out = Allocation.createTyped(renderScript, rgbaType.create(), Allocation.USAGE_SCRIPT);
        }
        in.copyFrom(nv21);
        yuvToRgbIntrinsic.setInput(in);
        yuvToRgbIntrinsic.forEach(out);
        Bitmap bmpout = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        out.copyTo(bmpout);
        return bmpout;
    }

在bitmap上写字(水印) 然后将bitmap转化为NV21数据推送出去

   byte[] bitmapToNv21(int inputWidth, int inputHeight, Bitmap scaled) {

        int[] argb = new int[inputWidth * inputHeight];

        scaled.getPixels(argb, 0, inputWidth, 0, 0, inputWidth, inputHeight);

        byte[] yuv = new byte[inputWidth * inputHeight * 3 / 2];
        encodeYUV420SP(yuv, argb, inputWidth, inputHeight);

        scaled.recycle();

        return yuv;
    }

    public  void encodeYUV420SP(byte[] yuv420sp, int[] argb, int width, int height) {
        final int frameSize = width * height;

        int yIndex = 0;
        int uvIndex = frameSize;

        int a, R, G, B, Y, U, V;
        int index = 0;
        for (int j = 0; j < height; j++) {
            for (int i = 0; i < width; i++) {

                a = (argb[index] & 0xff000000) >> 24; // a is not used obviously
                R = (argb[index] & 0xff0000) >> 16;
                G = (argb[index] & 0xff00) >> 8;
                B = (argb[index] & 0xff) >> 0;

                // well known RGB to YUV algorithm
                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;

                // NV21 has a plane of Y and interleaved planes of VU each sampled by a factor of 2
                //    meaning for every 4 Y pixels there are 1 V and 1 U.  Note the sampling is every other
                //    pixel AND every other scanline.
                yuv420sp[yIndex++] = (byte) ((Y < 0) ? 0 : ((Y > 255) ? 255 : Y));
                if (j % 2 == 0 && index % 2 == 0) {
                    yuv420sp[uvIndex++] = (byte)((V<0) ? 0 : ((V > 255) ? 255 : V));
                    yuv420sp[uvIndex++] = (byte)((U<0) ? 0 : ((U > 255) ? 255 : U));
                }

                index ++;
            }
        }
    }

//处理
    private byte[] parseByte(byte[] dst) {
        Bitmap bitmapAll = nv21ToBitmap(dst, mVideoParameters.width, mVideoParameters.height);

        Bitmap bitmapAllNew=bitmapAll.copy(Bitmap.Config.ARGB_8888,true);
        Canvas canvas = new Canvas(bitmapAllNew);
        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        paint.setColor(Color.WHITE);
        paint.setTextSize(30);
        canvas.drawText(name, mVideoParameters.width/2 -40, 60, paint);
        byte[] newBytes = bitmapToNv21(mVideoParameters.width, mVideoParameters.height,bitmapAllNew);
        if(newBytes!=null){
            return newBytes;
        }else{
            return null;
        }
    }

结束！