[clip transformation] Handle the "I just want to do cropping on a screencast" usecase in the viewer?
Submitted by Jeff F.T.
Assigned to Jeff F.T.
This is a non-cinema, non-"filmmaking" corner case, but many software devs (including various people in the GNOME community) experience this need.
There are 2-3 things to consider for the various "styles" of screencasting,
3 being the one prompting this bug report:
====== 1- Animatable zoom crop ======
This addresses the cases where:
- The size/position of windows change through time
- You want to focus specific parts of a tutorial on a tiny part of a UI
This is not really a crop, just a simulation of it. Does not actually require anything specific, it's part of how the "clip transformation" feature is meant to work anyway.
This is planned as the normal workflow. No specific action needed.
====== 2- Real "clip-level" cropping ======
Used for doing a splitscreen compositing effect, among other things.
We already do/allow this with the "crop" (videocrop) effect.
This already works. No action needed.
====== 3- Real "global/output" static cropping ======
This is what a portion of the "screencast crowd" wants to do. Basically, drag a rectangle on the viewer and say "crop to this rectangle": the app then crops the clip AND sets the project resolution (and position shifting, and all sorts of crazy things) to match that.
It is what has been described in somewhat unpolite terms on http://blogs.gnome.org/jessevdk/2012/07/17/video-editing-wtf/
(but it's not as simple as that, see further below)
This is the case where the whole screen was recorded during screencasting (because that's what gnome-shell does) but the window of interest does not move/resize (a "static" crop) and the user wants to "just cut off the extra/sides" and render without scaling or losing significant quality... and this is the tricky part, because this would imply we kinda lockdown the other worflows, and let the project settings + pipeline + encoders know about "you need to render only part of the image", and I'm not sure GStreamer even allows that.
UI-wise, it's tricky to design/integrate this feature the "right" way in a traditional video editor. I've never seen it in Vegas, Premiere, AE, FCP, etc. I'm wondering if this would rather be a candidate for making a standalone specialized cropping app (like avidemux, but simpler) for this.
Imported from https://bugzilla.gnome.org/show_bug.cgi?id=727312