• If the customer shoots the HD video using 29.97 frame/sec., it's 1080i
• It the customer shoots the HD video using 24 frame/sec., it's 1080p

More FYI: 24 fps is the frame rate used by moviemakers.  Most of the first generation HD cameras are not capable of recording 1080p video.  You should never convert from 1080p to 1080-i.  The resulting video will play with jerkiness.  You can convert 1080-i to 1080p but it requires a special pc hardware to get the video to play smoothly.