Fine with me, but will leave this to review by William and Sequencer team.

Not sure if changing property name to origin avoids confusion - it is origin of what?
"Text origin is center and left." Implies that text is aligned to center and left of image.

In T65458 @William Reynish (billreynish) showed image of text object in 3D Viewport, where this property is called Alignment

As for current behavior of alignment:
In 3D Viewport where space is infinite this does make sense - you have only origin of space to align with.
In VSE where you have clear boundary you always think in context of that boundary. So IMO no matter how you name things here, when user change alignment / origin from left to right, result will not meet expectations.

I would suggest:

• Let align property as-is peraps we can add fancy list icons as in 3D Viewport
• Change defaults as per @William Reynish (billreynish) suggestion
• Change code, so alignment works in context of image/preview/textbox boundaries. Not necessarily in this patch - it won't be so simple.

We can also remove alignment from UI if idea is to avoid confusion. But personally I would like text strip to be a bit more fancy than more basic.

In T71082#802737, @Andrzej Ambroz (jendrzych) wrote:

I just made set of icons, that would be descriptive enough for this function. Text Block Anchors:

Adding these icons here.
They actaully look a bit more descriptive so they can be used.

I will update the icon sheet shortly

What's the status on this?

@Paul (Thirio) The Text Block Anchors icons mentioned above are now included in Blender. Maybe 'anchor' is a better name than 'origin'?

@Richard Antalik (ISS) its the origin of the selected object, same behaviour as the origin of an object in 3d space. The word alignment is confusing as for alignment you need 2 origins. And alignment in typography means aligning the text-lines AND changing its origin.

If we can agree on origin I'll spend some time adding icons to this patch to wrap it up, else I'll abandon this patch and suggest someone more knowledgeable to implement actual text-alignment, using the same settings as 3d-text.

In D6178#169526, @Paul (Thirio) wrote:

@Richard Antalik (ISS) its the origin of the selected object, same behaviour as the origin of an object in 3d space. The word alignment is confusing as for alignment you need 2 origins. And alignment in typography means aligning the text-lines AND changing its origin.

If we can agree on origin I'll spend some time adding icons to this patch to wrap it up, else I'll abandon this patch and suggest someone more knowledgeable to implement actual text-alignment, using the same settings as 3d-text.

Icons were added now, it's still called alignment, but I think that icons are descriptive for what they do now.
I would agree, that it would be nice to have nicer and better featured text editor, but this is not really priority now.

If you want to develop this further, I made a design suggestion for Text Strips here: https://devtalk.blender.org/t/design-proposal-text-strips/12503