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like this video of the htc one. seems like a good feature to have.
http://www.youtube.com/watch?v=fL3MJzHs4Gk

I don't know of any tweak that integrates this feature right into the stock Videos app, that is, to avoid having to use third-party apps.

However, there are tons of even free AppStore apps that let for change the playback speed of even hardware-decoded videos (speed change being part of the official API). Want me to compile a list of these players for you?
 
I don't know of any tweak that integrates this feature right into the stock Videos app, that is, to avoid having to use third-party apps.

However, there are tons of even free AppStore apps that let for change the playback speed of even hardware-decoded videos (speed change being part of the official API). Want me to compile a list of these players for you?

sure if you can
 
sure if you can

Of the most recommended players (please see my other posts and reviews here at MR; I've posted tons of articles on the merits of these players),

AVPlayer(HD) (+/- icons in the center middle)
nPlayer (+/- icons in the center middle)
It's Playing (the "gauge" / "meter" icon in the top right corner)
RushPlayer(+) - that is, both the AppStore and the jailbroken versions (+/- icons in the center middle) (note that it does slow down / speed up the pitch of the audio, unlike the other players)
yaPlayer (1.0x icon in the top right; it's the first in the icon row)

Recommended ones that do NOT support speed change:
GoodPlayer
BUZZ Player
HD Player Pro
 
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