Re: voice-volume, absolute and relative volume units [css3-speech][css3-values][CSS-ISSUE-184]

On Wednesday 2011-07-06 22:34 +0100, Daniel Weck wrote:
> 
> On 29 Jun 2011, at 23:43, L. David Baron wrote:
> 
> >http://dev.w3.org/csswg/css3-speech/#voice-volume defines a relative
> >'dB' unit (which does make sense as a relative unit), which
> >CSS-ISSUE-184 proposes to move to css3-values.
> >
> >However, the 'voice-volume' property then says its computed value is
> >"specified value", which doesn't make sense for relative values.  In
> >particular, an element with 'voice-volume: +5dB' should have a
> >different computed value depending on what its inherited value was.
> >
> >We've had lots of problems in the past when we had properties whose
> >computed values couldn't be represented as valid syntax for the
> >property.  I think adding another such case (I think we've fixed the
> >existing ones, e.g., with the 'font-weight' changes in CSS 2.1) is a
> >bad idea.  So I think if you want relative units in this manner, you
> >should also have a syntax for combining them with the possible
> >absolute values.
> 
> I understand the problem you are describing, but I can't figure-out
> a way to solve it. Absolute values for the audio amplitude level are
> materialized via the x-soft, soft, medium, loud, x-loud keywords,
> but this is still dependent on the selected voice instance (and it
> is linked to the perceived loudness, i.e. to the user).

I think the simplest way to solve it is to allow compound values
like 'soft +5dB'.

-David

-- 
L. David Baron                                 http://dbaron.org/
Mozilla Corporation                       http://www.mozilla.com/

Received on Wednesday, 6 July 2011 22:44:50 UTC