html5 video: fastest fast forward and slowest slow motion?

Question

Wondering what the bounds are for variable rate playback with html5 video.

I seem to min and max out playing with this demo: http://www.w3.org/2010/05/video/mediaevents.html

I've done a cursory glance at the specification, but don't see anything there.

Answer 1

I have tested this on different computers cpu powers, and found that there is no upper limit. However, the fastest effective speed will be dependent on your cpu power. I got 15x maximum speed on corei7 -4770k @3.5Ghz and got around 10x on less powered haswell corei5 @2.5Ghz.

These are the chrome extensions used for changing the speed: chrome extension for chrome

another chrome extension with modifiable hotkeys (but it needs to be added to chrome by loading an unpacked extension)

Update:

Here is something related to Internet Explorer:

The playbackRate property represents a multiplier of the video's intrinsic or normal playback rate, with the default setting of 1. If you set the property to 2, it doubles the playback speed, while .5 will play at half speed. If playbackRate is set to a negative value, in Windows Internet Explorer 9, it rounds it back to zero, essentially pausing playback. In Internet Explorer 10, negative values for playbackRate cause the video to play in reverse. The W3C spec doesn't recommend an upper limit, but Internet Explorer limits playbackRate up to 8x speed.

Source: Using JavaScript to control the HTML5 video player