cropping a video - is it really so tedious?

[Dee-S]

So, I've been using Photoshop and After Effects for many years. Recently, I've tried out Premiere. And I've been struggling with the most mundane things. 

In particular, cropping.

I'm talking about adjusting a video size to part of the image. See, already, it's getting confusing : I need to define the term because I've been looking at tons of articles, videos, and they'll explain anything but that. They'll tell me how to mask part of the image (crop effect), then I'm left with this stupid black background all around. Or Auto resize, which doesnt crop either.
In Photoshop and After Effects, it's extremely simple, you'd just draw a selection and 2 clicks later, the working canvas will be auto-resized to the region of interest.

Is there no such efficient equivalent in Premiere? Are with stuck with painfully masking, then randomly fiddling with sequence size? Or having to use other programs to find the final sequence size?
I'm really confused, did I miss something out? Surely I must be doing something wrong.

[Mathias Moehl]

When creating video, you usually have particular target resolution like 1920x1080 or 1080x1080. Creating a video in a more or less random other resolution is rather uncommon. Therefore, the usual workflow is to create a sequence in a particular resolution and then scaling the footage inside of it to fit as needed.
After Effects is a different story, because in Ae you work with precomps a lot and for those precomps it in deed make sense to fit their size to a particular layer.

[Dee-S]

Unfortunately just what I expected. Thanks

[R Neil Haugen]

As Mattias mentions, video processing is different than stills. Very different. I came from a long stills career into video, been there done that. Don't even think of them as close!

Video always has defined data for at least two things: framerate (how many images per second) and framesize.

Clips of video media always have defined fps and size.

Sequences also must have defined fps and framesize.

And your clips will probably include framesizes, maybe even framerates, that differ from the sequence you are working with.

And so when you add media to a sequence, you can choose how it appears. And as you've noted, nomenclature matters.

It's "scaling", not cropping, in video post terms. 

The Preferences include three options for "automatic" scaling when media is added to sequences:

• None ... the clip isn't scaled at all, so dropping a large framesize clip on a smaller framesize sequence will seem "cropped".
• Scale To Framesize ... this was an early addition, back when computers struggled with framesize more than now. It rasterizes the clip to the sequence framesize, for easy playback and processing. But you probably do not want that, as any change you make on the sequence will be from the rasterized (processed) data, not the original data.
• Set to Framesize ... the one most suggested. This 'places' the framesize of the clip into the sequence, normally respecting the height but at times therefore losing some width. So there may be "black  bars" at the sides. But you are still technically dealing with the original pixels, so any changes to scaling you make manually will be from original pixels, with a better image than from the "Scale-to" option.

[Ann Bens]

Premiere has two different option: crop effect or masking on effects.

Premiere does not have a region of interest.

As for quickly determining the sequence size, use the Preview Area in the Project window.

[Dee-S]

Is there a way to determine easily the size of a specific part of the sequence? (so I can set the video to this size)

[Ann Bens]

No but why would you set the video to a different size.

Your sequence setting should be the same as your export settings to start with.

Premiere does work a bit different from Ps and Ae,

[Dee-S]

Often, I just want to crop a portion of the image and export it to an unorthodox size, regardless of the consequences (quality, compatiblity...) because it's perfect for the purpose

[Mathias Moehl]

The crop effects uses percentages. If you crop 12% from the top and 16%from the bottom, total crop amount is 12%+16% = 28%

and then the area left is

100% - 28% = 72%
If your total height is 1080 pixels, then 72% of that are 1080*0,72 = 777,6 pixels.

If you want to automate that calculation, I just created a tool with my (paid) extension Automation Blocks for Premiere Pro. You can download the tool here and load it in Automation Blocks (you also find it in the Community Library at "Clips/Size/Compute Size of Cropped Clip.xml").
Once you loaded the tool, just select any clip in your sequence, to which you applied a crop effect, and run the tool. It will show a popup box with the calculated width and height of the cropped area.

Here is the block code of the tool with some explanation how it works:

[Ann Bens · Accepted solution]

Export to AME : CROP on output video feature. Tells you exactly height and width and export as such.

[Dee-S]

It's really crazy how premiere is needlessly complicated. I really don't get it.