how to determine field order 

when it detects pure interlaced, dvd2avi doesn't say which order. i guessed wrong and the result looks real bad on my set top player.

this is an extract from AviUtil's site Automatic IVTC by AviUtl Open VFAPI project file (D2V, TPR), VDR or Reference AVI. Check Read as 60fps at the same time. Play forward by right arrow key. If it plays smoothly, the field order is right. If not, File -> General Settings -> Open video with delayed odd field then check this menuitem. Open video and Read as 60fps again, it will be fine now. That's the right field order to perform IVTC. It helped me to determine the right order. Bitrate viewer also reports the frame order Atreides if u r asking. Now that I am reading again your post it seems that u r making a remark.

Another way I noticed recently is to just browse the d2v file. All those one digit numbers are the flags for all the individual frames. If they are all 2's and 3's then you clip is Top First. If they are all 0's and 1's then it's Bottom First. Note also that if they are all just 0's and/or 2's then there are no repeat flags and you should NOT use Force Film, even though Decomb may still handle it just fine. I just started looking at these this way, but it seems to be fairly reliable. - Tom

interesting. i never thought to look at the d2v file. well i found that tmpegenc automatically detects the field order if i use the wizard :) so i tried it and sure enough the project i was working on was top field first whereas i'd assumed it was bottom field first.