NV12 Data

        y = width * height / 4;
        memset(buffer, 128, y);
        memset(buffer + y, 64, y);
        memset(buffer + y * 2, 128, y);
        memset(buffer + y * 3, 192, y);
        uv = width * height / 8;
        memset(buffer + y * 4, 0, uv);
        memset(buffer + y * 4 + uv, 64, uv);
        memset(buffer + y * 4 + uv * 2, 128, uv);
        memset(buffer + y * 4 + uv * 3, 192, uv);