use DM642 to capture Time-multiplexed Two Channel ITU-R BT.656 Format(54MHz)

i'm using a video decoder to output 2 D1 BT.656 data multiplexed into one 54MHz video data output. The logical timing diagram look like the following:

it seems using two polarity inverted 27Mhz clock(CLKP, CLKN), i can get the two channel BT656 data. The video decoder's datasheet says, it can insert Channel ID info into horizontal blanking or sync information. So if i use dm642's video capture port (bt.656 mode) can i differentiate the two channels? Will the vp port capture the horizontal blanking info or sync info?? Or any other ideas?

Thanks a lot.