Scale option

[peteruithoven]

Implements: https://github.com/Mohelm97/screenrecorder/issues/9 Allows users to scale the video to reduce file size. Uses ffmpeg's scale filter.

ToDo:

• [x] Use ffmpeg scale argument
• [x] Add option to UI
• [x] Add "%" unit to UI
• [x] Correct "@2x" in file name
• [x] Decide on UI

[peteruithoven]

Not sure about the UI. Just adding a column for "%" is a bit awkward? Maybe a small Gtk.Scale would be more appropriate? Maybe starting at 25%, with a marks at 50% and 75%. Although that introduces another UI type in the mix.

[peteruithoven]

Granite.ModeButton

Makes the interface a bit wide.

Gtk.Scale

Seems appropriate for a scale, but is quite busy.

Gtk.ComboBox

I like this the most, probably because it kind of blends in.

[peteruithoven]

@Mohelm97 Do you have an opinion on the UI?

[Mohelm97]

@peteruithoven Oh Thanks Peter, and sorry for not being active this whole time, I think I like the most the ComboBox :D

[peteruithoven]

@Mohelm97 No problem, I've implemented the Combobox. Please let me know if there is anything I should improve.

[Mohelm97]

@peteruithoven Just some questions to learn some stuff :D Do we need the m library? what do you think is better to scale it in the rendering or in the recording? If the scale option is less than 1, we should add something like 0.5x?

[peteruithoven]

Do we need the m library?

I needed it for Math.floor, but since that's the only usecase there might be a way to floor without this library. In Javascript there are a couple of ways: https://blog.blakesimpson.co.uk/page.php?id=58&title=fastest-alternative-to-math-floor-in-javascript. I could check whether that also applies to Vala?

What do you think is better to scale it in the rendering or in the recording?

I'm not sure, I'm not sure how do those options impact the user? Preferably something where the preview indicates the final result?

If the scale option is less than 1, we should add something like 0.5x?

No, the @2x is to communicate to websites like Github that they can be resized to 50%.

[peteruithoven]

I've now used a simple cast to int to floor a value, this seems fine: https://stackoverflow.com/questions/3300290/cast-to-int-vs-floor I've therefore also removed the math library.

If the scale option is less than 1, we should add something like 0.5x?

No, the @2x is to communicate to websites like Github that they can be resized to 50%.

The issue for screenshot: https://github.com/elementary/screenshot/issues/68 More info: https://ivomynttinen.com/blog/a-guide-for-creating-a-better-retina-web

I am going to change the logic though, I don't think we want websites to downscale images to 25% when users with a HiDPI screen take a recording at 200% scale and we also don't want websites to downscale images to 50% when users with a LoDPI screen take a recording at 200%. I think I'd like it to work like this: LoDPI (1x): 25% > 1x 50% > 1x 75% > 1x 100% > 1x 200% > 1x

HiDPI (2x): 25% > 1x 50% > 1x 75% > ? 100% > 2x 200% > 2x

HiDPI (4x): 25% > 1x 50% > 2x 75% > ? 100% > 4x 200% > 4x

[Mohelm97]

@peteruithoven Really thanks a lot for this awesome contribution Peter ;)