/**
 * Bitmap转化为ARGB数据，再转化为NV21数据
 *
 * @param src    传入的Bitmap，格式为Bitmap.Config.ARGB_8888
 * @param width  NV21图像的宽度
 * @param height NV21图像的高度
 * @return nv21数据
 */
public static byte[] bitmapToNv21(Bitmap src, int width, int height) {
    if (src != null && src.getWidth() >= width && src.getHeight() >= height) {
        int[] argb = new int[width * height];
        src.getPixels(argb, 0, width, 0, 0, width, height);
        return argbToNv21(argb, width, height);
    } else {
        return null;
    }
}

/**
 * ARGB数据转化为NV21数据
 *
 * @param argb   argb数据
 * @param width  宽度
 * @param height 高度
 * @return nv21数据
 */
private static byte[] argbToNv21(int[] argb, int width, int height) {
    int frameSize = width * height;
    int yIndex = 0;
    int uvIndex = frameSize;
    int index = 0;
    byte[] nv21 = new byte[width * height * 3 / 2];
    for (int j = 0; j < height; ++j) {
        for (int i = 0; i < width; ++i) {
            int R = (argb[index] & 0xFF0000) >> 16;
            int G = (argb[index] & 0x00FF00) >> 8;
            int B = argb[index] & 0x0000FF;
            int Y = (66 * R + 129 * G + 25 * B + 128 >> 8) + 16;
            int U = (-38 * R - 74 * G + 112 * B + 128 >> 8) + 128;
            int V = (112 * R - 94 * G - 18 * B + 128 >> 8) + 128;
            nv21[yIndex++] = (byte) (Y < 0 ? 0 : (Y > 255 ? 255 : Y));
            if (j % 2 == 0 && index % 2 == 0 && uvIndex < nv21.length - 2) {
                nv21[uvIndex++] = (byte) (V < 0 ? 0 : (V > 255 ? 255 : V));
                nv21[uvIndex++] = (byte) (U < 0 ? 0 : (U > 255 ? 255 : U));
            }
            ++index;
        }
    }
    return nv21;
}

     /**
         * bitmap转化为bgr数据，格式为{@link Bitmap.Config#ARGB_8888}
         *
         * @param image 传入的bitmap
         * @return bgr数据
         */
        public static byte[] bitmapToBgr(Bitmap image) {
            if (image == null) {
                return null;
            }
            int bytes = image.getByteCount();

            ByteBuffer buffer = ByteBuffer.allocate(bytes);
            image.copyPixelsToBuffer(buffer);
            byte[] temp = buffer.array();
            byte[] pixels = new byte[(temp.length / 4) * 3];
            for (int i = 0; i < temp.length / 4; i++) {
                pixels[i * 3] = temp[i * 4 + 2];
                pixels[i * 3 + 1] = temp[i * 4 + 1];
                pixels[i * 3 + 2] = temp[i * 4];
            }
            return pixels;
        }