TTS Speech API

TTS Speech API

 

Attached document is a start.

Uses the main template, maintaining the original format for easy
reintegration.

 

Includes relevant requirements and design decisions.

Some new TTS items noted through symmetry (see yellow highlights).

 

Recommend reformatting requirements and design decisions  in the main
document.

Use a table to note applicability of the items.

E.g., columns that indicate applicability to reco, tts.

Would avoid separate copy and update of this information.

 

Two major decisions:

1)      Use a TTS tag

2)      Basis of the approach

 

Use a TTS tag:

This is recommended for reasons similar to the reco tag.

For an HTML API, we should be able to do (very) simple things with just
markup.

Helps the API be more declarative.

Can control features through the standard DOM (similar to the audio
element).

Better for standard HTML developers (the main target?)

Provides a standard place to add event handlers.

Allows for visual control, e.g. patterned after the audio element.

Can support GUI related interaction considerations: focus and visibility.

Note: somehow recommendation of a TTS tag was dropped at the last minute in
the F2F meeting.

 

Basis of the approach:

Use a derivative of the audio tag.

Start with the Microsoft TTS proposal.

Should fit best with HTML5.

 

Other considerations:

 

Spoke about fallback approaches.

The <source> tag allows for multiple formats - can consider this approach.

Also have canPlayType method:

var source= document.createElement('source');
if (audio.canPlayType('audio/mpeg;')) {
    source.type= 'audio/mpeg';
} else {
    source.type= 'audio/ogg';
}
audio.appendChild(source);

 

Other documents:

 

CSS3 Speech Module

W3C Working Draft 19 April 2011

http://www.w3.org/TR/css3-speech/

 

Aural Stylesheets

http://www.w3.org/TR/CSS21/aural.html

http://www.w3.org/TR/css3-speech/#property-index