Hello @malcolm,
I am trying to use AJA card for 1080i50 video input. I feel like deinterlacing (using Bob) doesn’t work as expected. It seems to me only first or second fields are used. It could be that I am missing something, I haven’t worked with interlaced signal for a while now, but visually it doesn’t look right (it feels like 25 instead of smooth deinterlaced 50).
Also I would like to ask whether you think it might be possible to somehow use Sync to Input mode for such interlaced signal, while still doing deinterlacing - running at 50fps? Right now TD drops to 25fps when I choose Sync to Input mode, which actually makes sense given the signal characteristics, but unfortunately isn’t really usable. I guess there isn’t much to do in this case - since TD basically locks to 25fps signal (even though under the hood it contains 50fps data), but I wanted to ask. Thanks.
Using latest stable build 2023.12230, AJA Corvid 44 12G with latest firmware (c44_12g_8k_mk_tprom.bit), NTV2 SDK 17.1.3 along with driver packed with this release.
I am sorry to bump this, but I am trying to decide whether to get interlace → progressive convertor, or rather wait and see if deinterlacing could work with AJA. In case you might have some info regarding deinterlacing issue, please let me know - I would buy the converter or wait based on that. 
Thanks.
Hey, sorry, this was on my todo to answer.
I’ll definitely look into the deinterlacing issue sometime, but it may be a few weeks still.
The Sync to Input feature being based on the fields is likely not something we’ll add, since interlaced formats will only get used less and less going forward.
No problem, thank you very much for info. For the time being I will go with the hardware converter and in case you might find some solution in the future I will swap it out.
Regarding Sync to Input - yeah, I completely understand. Interlace should be gone by this time, but somehow it still lives is some areas (I really don’t like interlace). 
Thanks once again.
Hello, I just want to let you know that this problem isn’t related just to AJA devices. I have tried deinterlacing also with Blackmagic device today and it seemed to have the same issue.
P.S. For future readers out there - don’t but that Mini Converter UpDownCross HD I have mentioned earlier for this task. Technically if converts interlace → progressive, but it doesn’t perform proper deinterlacing (it just copies first field to both progressive frames - which means output looks like 25fps). On the other hand Datavideo DAC-70 does perform proper deinterlacing (but I suspect it might have some other problems in terms timing of its output signal - I am not entirely sure about that but be cautious when using it in your video pipeline).