Rotate Youtube Video (+ Zoom / Mirror) 作者： znwyrz

Rotate
- support 0°, 90°, 180°, 270°
- affect Youtube video preview

Zoom / Mirror
- support zoom (scale), translate x,y , crop, mirror (flip)
- support long press +,- button
* the value will be reset after pressing the reset button or the rotate button
* not affect Youtube video preview
* need to adjust value for normal mode and full screen mode

Shortcuts
- Rotate : ctrl+shift+9
- Zoom in : ctrl+shift+.
- Zoom out : ctrl+shift+,
- Move left : ctrl+shift+arrow-left
- Move right : ctrl+shift+arrow-right
- Move up : ctrl+shift+arrow-up
- Move down : ctrl+shift+arrow-down
- Mirror : ctrl+shift+8
- Reset Zoom/Move/Mirror Options : ctrl+shift+7

Shortcuts with mouse
- Zoom : on player > shift+scroll
- Move : on player > shift+left-click+move
- Reset Zoom/Move/Crop/Mirror : on player > shift+middle-click

You can change Shortcuts via Manage Extension Shortcuts
- How to Manage extension shortcuts : <a href="https://support.mozilla.org/en-US/kb/manage-extension-shortcuts-firefox" target="_blank">link</a>
- Possible Key Combinations : <a href="https://developer.mozilla.org/en-US/Add-ons/WebExtensions/manifest.json/commands#Key_combinations" target="_blank">link</a>