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Re: [css3-speech] voice-pitch and voice-pitch-range computed values

From: Daniel Weck <daniel.weck@gmail.com>
Date: Wed, 13 Jul 2011 21:16:13 +0100
Message-Id: <DB8AD3C0-938C-4800-BE22-C878D301B91A@gmail.com>
To: www style <www-style@w3.org>, fantasai <fantasai.lists@inkedblade.net>
I'm with you, thank you for the clarification / enlightenment.
But we also need the computed value to allow absolute frequencies in addition to the keyword enumeration (the initial value is 'medium' but it may be overridden with, say, "200Hz"):
 
Computed value:
an absolute frequency or keyword value, and potentially, a frequency, semitone, or percentage representing any non-zero offsets.

Does that sound right?

On 13 Jul 2011, at 19:47, fantasai wrote:

> http://dev.w3.org/csswg/css3-speech/#voice-props-voice-pitch
> 
> Value:          <frequency> && absolute? | <semitones> | <percentage> | x-low | low | medium | high | x-high
> Initial:        medium
> Applies to:     all elements
> Inherited:      yes
> Percentages:    refer to inherited value
> Media:          speech
> Computed value: specified value
> 
> "Specified value" isn't going to work because if I have
> 
>  <parent>
>    <child>
>      <grandchild/>
>    </child>
>  </parent>
> 
>  parent {
>    voice-pitch: low;
>  }
> 
>  child {
>    voice-pitch: 2st;
>  }
> 
> then child and grandchild should both have "low + 2st"; grandchild
> should not be 2st higher than child.
> 
> The two technical options here are:
>  - compute an absolute frequency
>  - maintain a keyword and an offset
> 
> The difference in behavior would be discernable when the voice changes;
> the latter would maintain the frequency of the old voice, whereas the
> new one would recompute using the base frequency of the new voice.
> 
> The first behavior, however, is not useful: consider a switch from male
> to female voice: if voice-pitch inherits as an absolute frequency, then
> the pitch would be incorrect even in the simple case of 'voice-pitch'
> never being specified.
> 
> So we have to use the second, perhaps something like
> 
> Computed value: a keyword and, potentially, a frequency, semitone, and/or
>                percentage representing any non-zero offsets.
> 
> ~fantasai
> 
Received on Wednesday, 13 July 2011 20:16:58 GMT

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