XnView Software

I have a question on this format - this is supposed to take a file with an image segmented into 2 fields (I shall call this interlaced format), interleave the fields then display the result as a progressive image.

However, can someone please confirm which field is displayed first and which field gets the extra line when there is an odd number of lines.

I think the answers are 1st field and 2nd field respectively. If this is the case could we please have an option to have the extra line in the 1st field instead? The reason for this is that in digital interlaced TV the 2nd field has 1 more line than the 1st for odd lines when taking vertical blanking into account, but when just considering the active part this actually swaps around so I would like the ability to display both with an option in the YUV Options screen.

Having done some further investigation I would say that XnView has a bug with this format when there is an odd number of lines.

I created 3 interlaced files with different coloured lines:
20x4: Field 1: White/Green; Field 2: Grey/Pink
20x5: Field 1: White/Green; Field 2: Grey/Black/Pink
20x5: Field 1: White/Black/Green; Field 2: Grey/Pink

- 20x4 is displayed correctly (even # lines)
- 20x5 with Field 2 having 1 more line is displayed as White/Grey/Green/Black/Black which is correct at the top but misses Pink
- 20x5 with Field 1 having 1 more line is displayed as White/Green/Black/Grey/Black which is completely wrong and also misses Pink

I think we definitely need an option to select the field with the extra line in and that line must be displayed first. Currently we have Field 2 with the extra line but Field 1 is displayed first which causes problems at the end of the frame where there is a missing Field 1 line but an extra Field 2 line.