[Sam Lee] “Is 60i is another way to express it as 59.94 fields (29.97 frames * 2 fields = 59.94 fields, established back in ’53 by NTSC), which is essentially 29.97 interlaced frames for US broadcast?”
Yes, and as you agree, it is a very bad / stupid way of describing normal speed interlaced.
[Sam Lee] ” 60p is actually recording at 59.94 fps frequency”
Not always. 60p (as well as 30p) actually exists. (Mostly in consumer / action cams.)
So, sometimes it’s 60 or 30, sometimes it’s 59.94/29.97.
(And yes, that sucks too if it’s not always the correct number.)
[Sam Lee] “60i recorded clip after de-interlacing (using hi-quality method) is effectively equivalent to 29.97p.”
I though we just established that 60i DOES NOT exist?
For the 0.1 % speed difference, a speed change (if needed) is very well acceptable, just pitch shift the sound as well to stay sync.
[Sam Lee] “Most broadcasters are OK with interlaced video.”
I would say ALL broadcasters, except Netflix and other online platforms.
[Sam Lee] ” If it’s mixed with progressive scan, then deinterlace it to match.”
Why? If the mix looks good, it is good. (Especially motion graphics can be interlaced in a progressive sequence.)
Bouke
http://www.videotoolshed.com