ADV7181C采集VGA图象不正常

我在使用ADV7181C采集PC输出的VGA图象，图象分辨率是1024x768,ADV7181C被设置成SDR-16bit-YUV422输出，寄存器设置如下(省去了器件地址0x42)：

unsigned char adv7181c_regs[]={
//##CP XGA 1024x768##
//:RGB 1024x768 _@ 60Hz 12-Bit DDR 65.000MHz Out through HDMI:

0x03, 0x02<<2, //16-bit @ LLC2 4:2:2 LLC2=LLC1 /2

0x05, 0x02, // Prim_Mode =010b for GR
0x06, 0x0C, // VID_STD=1100b for 1024x768 _@ 60
0xC3, 0x46, // ADC1 to Ain4, ADC0 to Ain6,
0xC4, 0xB5, // ADC2 to Ain5 and enables manual override of mux
0x1D, 0x47, // Enable 28MHz Crystal
0x3A, 0x21, // set latch clock settings to 010b, Power Down ADC3
0x3B, 0x61, // Enable Internal Bias
0x3C, 0x5D, // PLL_QPUMP to 101b
0x6A, 0x00, // DLL Phase Adjust
0x6B, 0x83, // Swap Pr & Pb
0xC9, 0x00, // Set DDR_DISABLE
0x73, 0x90, // Set man_gain
0x7B, 0x1D, // TURN OFF EAV & SAV CODES Set BLANK_RGB_SEL
0x85, 0x03, // Enable DS_OUT
0x86, 0x0B, // Enable stdi_line_count_mode
0xF4, 0x3F, // Max Drive Strength
0x0E, 0x80, // ADI Recommended Setting
0x52, 0x46, // ADI Recommended Setting
0x54, 0x00, // ADI Recommended Setting
0xF6, 0x3B, // ADI Recommended Setting
0x0E, 0x00, // ADI Recommended Setting
0x52, 0x80, // ADI Recommended Setting
0x57, 0x08, // ADI Recommended Setting
0x5B, 0x20, // ADI Recommended Setting
0x5C, 0x00, // ADI Recommended Setting
0x62, 0x00, // ADI Recommended Setting
0x63, 0x01, // ADI Recommended Setting
0x67, 0x03, // ADI Recommended Setting
0x68, 0x01, // ADI Recommended Setting
};

采集到的图象如下：