You will need to install a user script manager extension to install this script.
12/12/16 Fixed seeking forward, I think Chrome changed something right when this script was promoted to front page lol
08/07/16 Correct initial speed display, instead of always displaying '1.00' on page load
11/21/15 Update: now also works with external site embedded YouTube videos
YouTube Video Speed & Seek Mouse ControlUses YouTube's HTML5 player and the mouse scrollwheel to control playback:
hold 'shift + wheelup / wheeldown' to 'jump forward / back' (seek +/- 5 seconds, 10s embeds)
hold 'alt + wheelup / wheeldown' to 'speed up / down' (speed +/- 0.25 rate)
For embedded videos - just click once anywhere inside the embedded YouTube player to give it key focus for the script to work
Works on both normal and fullscreen player.
A small text display will appear above the top-right of the video to indicate current playback speed.
VLC Player Video Speed & Seek Mouse ControlI also wrote a version that works with VLC Player for when watching local videos. It uses Autohotkey (a free utility program), copy/paste the code below into a blank text file, save as (for example) "vlc_mousecontrol.ahk" and double-click the file to run. It uses the same shift/alt + mousewheel controls as 'YouTube Video Speed & Seek Mouse Control' listed above:
#IfWinActive ahk_class QWidget