dm8168 NTSC output was always WHITE

Hi:

I has configured 0x48105e04'  4 bit  to be 1,

and got the right colorbar displayed on screen  from   dm8168 SD_DAC  port, 

but when I run my demo_cap_dis program , the figure is alway s white.

I modified demo_cap_dis in dvr_rdk to be follows:

CAP(720P, 422i_yuyv)

                   |

                   |

                  \|/ 

   DISPLAY2(NTSC)

could I link like this? and why it always display white?

would any one help me ?

Thanks a lot!

best regards!