Documentation - Interlacing and Field Order
I was going to assist another user with information about de-interlacing footage in the forum, but was appalled at the quality of the Adobe guide on this functionality.
https://helpx.adobe.com/premiere-pro/using/interlacing-field-order.html
Version Information
Currently V23 and V24 of Premiere Pro are supported (and also V22 for enterprise). Which versions of Premiere Pro does this page apply to?
Illustration
The illustration is poorly thought out. The upper “A&B” illustration should make clear that the field scanning happens consecutively in time, but the size differences and the 2 arrows for A and B fields confuse this issue (the time axis should be 1 line along which the viewer travels). Also this illustration is a lost opportunity to make upper/lower, odd/even field (the lexicon) clear. Also, field scanning is best illustrated by a visual subject's movement across 2 feilds, resulting in combed details (absent here) on the final frame and contrasted with 1 progressive frame. Finally, the “progressive” frame still has the alternating scanline look of 2 fields? Why? Confusing.
Field dominance and field reversal
This is the first time on the page that we’ll discuss field order, but the section doesn’t define “field dominance” nor does it state that field order and field dominance are the same thing. Clarity: define your terms. This section talks about how field order can become reversed. Then it finishes. All done with field dominance?
Create interlaced or non-interlaced clips
In spite of this title, this section is not about creating clips (neither interlace or non-interlaced), but modifying how fields are interpreted as frames within clips, or how frames can be modified creating fields within clips. This kind of imprecise language is precisely how users get frustrated or become confused.
The section starts out being about de-interlacing, or creating de-interlaced frames in a clip. Then suddenly we’re talking about field order mismatch and reversing field order (if we don't know that field order and field dominance are the same thing, suddenly we think we're talking about something new, but actually we're back to the previous section) … shouldn’t this be part of the field dominance section above? What has this got to do with de-interlacing or creating fields? Let’s be clear … field order mismatch issues and de-interlacing (along with interlacing) are two distinct things.
Then we’re discussing how to create fields from frames suddenly, but we’ve sort of arrived here trying to understand the “processing options” for Reverse Field Dominance. I can assure you that if you are trying to reach someone who is trying to learn how to “interlace clips created by animation applications not capable of generating interlaced frames.” they have not made it through field order mismatch, reversing field order, and processing options for same to arrive here.
But let's push on:
Interlace Consecutive Frames
What I’m seeing is that this option is not always available. Or maybe it’s no longer available in Premiere Pro? Some explanation as to when this appears / doesn’t appear would be helpful.
Always De-interlace
Here’s an odd software design choice … because the option here is “always” de-interlace. Not “sometimes” (did I miss that option somewhere?). Makes me wonder about the other options. It makes me wonder about speed options ("always" reverse speed or just sometimes?). It makes me wonder about sequence settings ("always" 48kHz or just sometimes?). It makes me wonder about keyboard shortcuts ("always" save with command S?) It makes me wonder about so much. Suggestion: how about just a "de-interlace" option, and I'll just assume the software always does it when that checkbox is checked?
But there is some real information listed here on how Premiere Pro achieves this. (Thanks!) However, it says Premiere Pro “interpolates the missing lines based on the lines of the dominant field.” The problem is that “interpolate” can mean many things. Does it double lines? Or does it create completely new lines based on the those above and below? Dictionary definition of “interpolate” is: insert, alter, interject. Users are left to guess.
Flicker Removal
It doesn’t say “always” so …
“Note”
There’s a special note that in progressive sequences, the “always de-interlace” option “retains the upper field”. Best to be clear here and emphasize that the lower field is discarded. Here’s a good computer rule: always tell the user when you’re discarding information. Users want to know.
“Note” (not the same as above, this the next note)
This note directs users to Choose Clip > Video Options > Frame Blend.
Of course, this is incorrect and should read Choose Clip > Video Options > Time Interpolation > Frame Blend.
But this note should probably also direct users to where this exact same setting is available in the “clip speed / duration” dialog box.
But also, why is Optical flow not discussed here?
Change the Field Order of a Clip
Okay … so this is the third time on this page we’re dealing with field order. This is not a good way to structure the page.
Also … suddenly we’re talking about “all instances of a clip in all sequences of a project”. Suddenly I’m doubting what I’ve learned above. Do the things I’ve learned above apply to all instances? Maybe not because suddenly this is new here. Above it told me I could “Select a clip in a Timeline panel or in the Project panel.” … do they lead to different outcomes on the level of “all instances”? This secton introduces a new concept (how this affects clips across a project) that leads me to question how the information above fits into this previously undiscussed aspect.
Missing Information
There’s no mention on the page of how the Time interpolation settings interact with de-interlace when it is 100% speed. Does it improve the de-interlace? Do nothing? More guessing.
Edit: More Missing Information
Apparently Premiere Pro does automatic de-interlacing (if you place an interlaced clip in a progressive timeline). This is not mentioned anywhere on this page. As this is likely the primary source of questions on this matter, it should be prominent, along with how this automatic interlacing is acheived, and how the time interpolation settings interacting with this automatic process. And from a software design perspective, if there is an "automatic" effect like de-interlacing affecting a clip, there should be some indication somewhere (on the fx badge?) that such a thing is occurring. Feedback. Users want to know.
And finally, from all the above, it seems that progressive clips can be modified to be "interlaced", but if these are placed in a progressive timeline ... are they automatically de-interlaced? The aspect of how clip and timeline settings interact needs to be addressed and presented in a clear way.
This page leaves me with the impression that whoever wrote it does not understand the tech - the exact opposite of what I want to feel when I read a manual. It is a murky mix of “how-to” and reference manual, without being useful as either.
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