Use HDMI and CVBS simultaneously

mori

Hi, I use Orange Pi One (Debian Jessie image) and wired TVOUT (CVBS) from solder pad.
I modified script.bin to use TVOUT and added "tv" module in "/etc/modules", then I can see picture of HDMI or CVBS only one by changing disp_mode = 0 or 1 , but cannot use them simultaneously.
My goal is, usually use TVOUT (NTSC) without HDMI cable and sometimes use HDMI 720p@60, without reboot.
Anyone have information or fex example?