- From: <bugzilla@jessica.w3.org>
- Date: Fri, 23 Dec 2011 00:02:34 +0000
- To: public-html@w3.org
https://www.w3.org/Bugs/Public/show_bug.cgi?id=15318 Summary: Define media.preservePitch attribute Product: HTML WG Version: unspecified Platform: All OS/Version: All Status: NEW Severity: enhancement Priority: P2 Component: HTML5 spec (editor: Ian Hickson) AssignedTo: ian@hixie.ch ReportedBy: giles@mozilla.com QAContact: public-html-bugzilla@w3.org CC: mike@w3.org, public-html-wg-issue-tracking@w3.org, public-html@w3.org HTML media elements have a playbackRate attribute which can be used to adjust the playback rate. For video this just involves changing the display rate for frames. For audio the situation is more complicated. The simplest method is to resampling the audio relative to the audio device's playback rate. This results in a pitch shift: playbackRate > 1.5 or so is high and squeeky, playbackRate < 0.8 is low and echo-y. There are also more sophisticated methods which attempt to preserve the spectral character so that perceived pitches are preserved, though usually with some reduction in fidelity where music is concerned. There are reasonable use cases for both pitch-preserving and pitch-shifting cases, and the specification currently leaves the decision to implementors. Apple initially implemented the pitch-preserving case, but later added a 'webkitPreservesPitch' boolean attribute to control this choice.[1] Looking at how we'd support playbackRate in Firefox, we found this a useful distinction and suggest such an attribute be added to the specification. e.g.: interface HTMLMediaElement : HTMLElement { attribute boolean preservePitch; }; The element could default to true, since this is the less objectional behaviour and is compabtible with webkitPreservesPitch. [1] http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2009-July/021100.html -- Configure bugmail: https://www.w3.org/Bugs/Public/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
Received on Friday, 23 December 2011 02:33:55 UTC