Handling true interlaced video without losing any detail

[Mawazi]

I'm converting a PAL 25fps DVD which is interlaced, with each field occurring at a different point in time. I'd like to end up with 50fps video that retains all of the original field information, with each field interpolated/resized to achieve the proper aspect ratio (in this case, 720x576) and avoiding the jittering of each new frame up and down.

Is that basically what QTGMC does? I keep reading it described as throwing out one field of each frame, which sounds like it is discarding useful information.

Thanks for any help.

[kuchikirukia]

QTGMC does what you want by default. Just be prepared for slooooooooow.

[colours]

I keep reading it described as throwing out one field of each frame, which sounds like it is discarding useful information.

That's only if you set inputtype=2 or 3, which is for progressive input and not what you want. The default value is 0 (for interlaced input) so this shouldn't be a concern.

You might also want to look into the SourceMatch and Lossless options, which make the the deinterlaced result more closely match the source on the non-interpolated fields. That said, using these options will sometimes lead to artifacts, so be sure to check the video.

[Mawazi]

Thank you, kuchikirukia and colours!

[kalehrl]

If it is too slow for you using default settings, try using Preset="Super Fast".
It is much better than Yadif even with this fast preset.
I don't think the author recommends using faster presets than Super Fast.

[Stormborec]

You can compare with this "best" setting:
from author: http://forum.doom9.org/showpost.php?p=1580001&postcount=1264

The most "accurate" reasonable settings I've measured (measured by best SSIM that doesn't introduce any noticeable artifacts) are:
QTGMC( Preset="Very Slow", EZKeepGrain=0.5, SourceMatch=2, Lossless=2, Sharpness=0.1, Sbb=0 )
Although the exact EZKeepGrain and Sharpness setting depend on noise and motion in the video respectively.

Superfast is the fastest presset which uses NNEDI. Ultrafast uses Yadif (but perhaps yet better than Yadif alone), Draft uses Bob