On Wed, Mar 2, 2016 at 2:36 AM, Philip Jägenstedt <[email protected]> wrote:
> On Wed, Mar 2, 2016 at 5:08 PM, Paul Adenot <[email protected]> wrote:
>>
>> Gecko uses code that can do arbitrary pitch adjustment, unrelated to
>> time-stretching (which is speed change with pitch compensation).
>
> That's neat. If you're interested in exposing this as an API on
> HTMLMediaElement, can you file a spec bug with a proposal of how it
> might work?
>
Here is what I had in mind; hope it helps.
Create a new property `pitchAdjustment` on HTMLMediaElement to adjust
pitch in cents.
Equally tempered semitones span 100 cents.
The developer can use INPUT type="range" with an oninput, to allow the
user to adjust the video's pitch, in cents.
interface HTMLMediaElement : HTMLElement {
attribute unsigned short pitchAdjustment;
…
}
pitchAdjustment adjusts the target HTMLMediaElement's audio pitch
relative to its original pitch, in cents. A value of 0 represents no
pitch adjustment.
Getting gets the last set value; 0 if unset. Setting sets the value
and changes the pitch in cents (relative to the media element's
original pitch).
Example:
<video src="mediasource:http://example.net/"; id="vv""></video>
<!-- transpose video up a 4th or down a 5th -->
<input type="range" min="-500" max="500" value="0"
onchange="updateMoviePitch()">
function updateMoviePitch(ev) {
var vv = document.getElementById("vv");
vv.pitchAdjustment = +this.value;
showPitchUI(vv, this.value);
}
Thank you,
--
Garrett
@xkit
