YUV2RGB

效率不是很够，数据量不大可以使用

public Bitmap convertYUV420_NV21toRGB8888_RenderScript(byte[] data, int W, int H) {
    RenderScript rs;
    ScriptIntrinsicYuvToRGB yuvToRgbIntrinsic;
    rs = RenderScript.create(MyApplication.getAppContext());
    yuvToRgbIntrinsic = ScriptIntrinsicYuvToRGB.create(rs, Element.U8_4(rs)); //Create an intrinsic for converting YUV to RGB.

    Type.Builder yuvType = new Type.Builder(rs, Element.U8(rs)).setX(data.length);
    Allocation in = Allocation.createTyped(rs, yuvType.create(), Allocation.USAGE_SCRIPT); //an Allocation will be populated with empty data when it is first created

    Type.Builder rgbaType = new Type.Builder(rs, Element.RGBA_8888(rs)).setX(W).setY(H);
    Allocation out = Allocation.createTyped(rs, rgbaType.create(), Allocation.USAGE_SCRIPT); //an Allocation will be populated with empty data when it is first created

    in.copyFrom(data);//Populate Allocations with data.

    yuvToRgbIntrinsic.setInput(in); //Set the input yuv allocation, must be U8(RenderScript).
    yuvToRgbIntrinsic.forEach(out); //Launch the appropriate kernels,Convert the image to RGB.

    Bitmap bmpout = Bitmap.createBitmap(W, H, Bitmap.Config.ARGB_8888);
    out.copyTo(bmpout); //Copy data out of Allocation objects.

    return bmpout;

}