- From: Eric Carlson <eric.carlson@apple.com>
- Date: Tue, 04 May 2010 21:04:02 -0700
- To: Janina Sajka <janina@rednote.net>
- Cc: HTML Accessibility Task Force <public-html-a11y@w3.org>, WAI-UA list <w3c-wai-ua@w3.org>, John Foliot <jfoliot@stanford.edu>
On May 4, 2010, at 6:56 PM, Janina Sajka wrote: > Silvia Pfeiffer writes: >> Correction to my previous email: >> >> The HTML5 media elements already have an attribute to control the playback rate: >> >> attribute float defaultPlaybackRate; >> >> (see http://www.whatwg.org/specs/web-apps/current-work/multipage/video.html#media-elements). >> > Well, since we're a W3C working group, I think we're looking at: > http://dev.w3.org/html5/spec/Overview.html#dom-media-playbackrate > > Glad to see it's there, but not sure whether it's complete per the UAWG > requirements: > * I don't see a supported range. UAWG wanted .5 to 2.0, which is > * not particularly large. > * I also believe we have a requirement for maintaining pitch > * during the time-scale modification. Perhaps that's what the > * editor's drft means when it says "monotonically," though I'm not > * sure that's the best terminology. > > In my opinion this will be an important feature for I18N as well as A11Y > support. For instance, anyone listening to content not in their native > language will doubtless discover enhanced comprehension by reducing > playback rate--provided pitch is maintained and no negative artifacts > are produced by the transformation. > I don't think we will be able to make pitch correction a MUST requirement as it is *extremely* computationally expensive and will likely not be possible - at all - on all supported hardware configurations. eric
Received on Wednesday, 5 May 2010 04:04:37 UTC