De-Interlacing in Final Cut Pro X

You should set the 60i media to whatever the actual frame rate of media is.

The Apple video is 59.94. You should set the project to that frame rate.

There is a Deinterlace function in the clip Settings in the Info inspector. By putting the clips in a progressive project they are deinterlaced to produce that output. Freeze frames are deinterlaced. Exported frames are deinterlaced. Interlaced and progressive media can be mixed in the same project.

60i is interlaced. It’s either 30i or 29.97i. It does not have to be 29.97i.

It doesn’t really matter if you use 59.94 or 60 for iPhone video. The video is nominally 59.94, but variable. 59.94 is I presume the rate Apple uses for playback on its Apple Devices. Sure use 60. Fractional frame rates are stupid these days.

You don’t have to do anything with the Deinterlace setting if you use a progressive project. The function is there of you want to export an interlaced clip as progressive.

If your shooting 1080 use 1920x1080 30p for the project and export that.

The timeline should be set to whatever the frame rate of the video is in progressive rather than interlaced. Current iPhones shoot 30fps, but oddly 59.94fps. Though that’s only nominally as they shoot battle frame rate, which is major pain in some instances.

Do you have FCP? Select a clip and the inspector shows the frame rate and i or p.

Set the project to what you want to output. For the web always use progressive. Ignore interlace unless you have a special need that I can't imagine.

60p works ok in a 30p timeline. Every other frame is discarded, unless you want slow motion.

My deinterlacing memo:

PAL and NTSC .dv are lower (bottom, even) field first (dominant). The upper (top, odd) field comes after that. Notice that if a clip was shot with slow shutter speed like 1/25 s, then that clip is in effect progressive. Notice also that the correct interlacing might have been distorted by careless scaling and after that even a correctly done deinterlacing might well have artefacts.

You can deinterlace SD PAL .dv in two ways:

a) Preserve the top (or bottom) field and 25fps with a simple deinterlace:

File > New... > Project > PAL SD [720x576, 25p]. Window > Show in Workspace > Info Inspector > Settings [at lower right pop-up] > Field Dominance Override > Upper First (or Off = Lower First. Progressive = both fields. Deinterlace OFF/ON does not seem to make any difference here). File > Share > Apple Devices 1080p..., H.264 Better Quality [768x576 | 25fps].

I guess it is up to you which field to leave (the old 32-bit MPEG Streamclip leaves the top field and omits the bottom field).

b) Preserve both fields and double the frame rate to 50fps i.e. bob deinterlace:

-> File > New... > Project > Custom 768x576 50p. Window > Show in Workspace > Info Inspector [cmd-4] > "i" [at upper right] > Settings [at lower right] > Field Dominance Override [at upper right] > Off = Lower First (Deinterlace OFF/ON does not seem to make any difference here). File > Share > Apple Devices 1080p..., Format: Computer, H.264 Better Quality [768x576 | 50fps].

I use PAL but these settings modified for NTSC seem to work:

Preserve both fields and double the frame rate to 59.94fps i.e. bob deinterlace for rectangular pixel 720x480 4:3 interlaced 29.970 FPS DVCPRO NTSC (16:9 and PAL have different values):

File > New... > Project > Custom 640x480 59.94p. Window > Show in Workspace > Info Inspector [cmd-4] > "i" [at upper right] > Settings [at lower right] > Field Dominance Override [at upper right] > Off = Lower First (Deinterlace OFF/ON does not seem to make any difference here). File > Share > Apple Devices 720p... [1080p... does not seem to make a difference], Format: Computer [or AppleDevices], H.264 Better Quality .mp4 [or Apple Devices .m4v and HEVC 8-bit, 640x480 | 59.94fps].

16:9 NTSC needs 854x480 and 16:9 PAL 1024x576. I usually try to preserve the vertical resolution to avoid interlacing artifacts but maybe some even vertical integer like 2x (2x480 -> 1280x960 for NTSC and 2x576 -> 1536x1152 for PAL) might be OK.

...

My current workflow with ffmpeg (installed via MacPorts. Use '-crf 28 -preset medium' for the somewhat lower quality default settings):

.dv to .mp4 H.265 (bob deinterlace, scale 788x576, crop 768x576, H.265, CRF18, slow, timecode, hvc1, AAC):

PAL .dv batch:

for i in *.dv; do ffmpeg -i "$i" -vf bwdif=1,scale=788:576,crop=768:576:10:0,setsar=sar=1/1 -c:v libx265 -crf 18 -preset slow -timecode 00:00:00:00 -tag:v hvc1 -c:a aac -b:a 128k "${i%.*}_converted.mp4"; done

individual PAL .dv clips:

ffmpeg -i input.dv -vf bwdif=1,scale=788:576,crop=768:576:10:0,setsar=sar=1/1 -c:v libx265 -crf 18 -preset slow -timecode 00:00:00:00 -tag:v hvc1 -c:a aac -b:a 128k output.mp4

...

.dv to .mp4 H.264 (bob deinterlace, scale 788x576, crop 768x576, H.264, CRF18, slow, timecode, AAC):

PAL .dv batch:

for i in *.dv; do ffmpeg -i "$i" -vf bwdif=1,scale=788:576,crop=768:576:10:0,setsar=sar=1/1 -c:v libx264 -crf 18 -preset slow -timecode 00:00:00:00 -c:a aac -b:a 128k "${i%.*}_converted.mp4"; done

individual PAL .dv clips:

ffmpeg -i input.dv -vf bwdif=1,scale=788:576,crop=768:576:10:0,setsar=sar=1/1 -c:v libx264 -crf 18 -preset slow -timecode 00:00:00:00 -c:a aac -b:a 128k output.mp4

Why don't you try reading the User Guide?

In FCP, go to the Help menu and enter this into the search field: "Add an interlaced clip to a non-interlaced (progressive) project". Or, if you have the PDF version of the User Guide, go to page 557. The info provided is quite clear and has some images, too...

Interlaced video info: https://en.wikipedia.org/wiki/Interlaced_video

You can check the frame rate in FCP. 60i is almost never 60fps. Do not put it in a 60p project. The frames will be doubled.

Yes, it matters. Don’t use the setting to Deinterlace if you are putting the clips in a progressive project.