Read Etexts now supports Text To Speech

[James Simmons]

I know there are several people interested in having Text to Speech with 
Karaoke highlighting be a built in part of the Sugar environment.  Also, 
when I originally requested a Git repository for the Read Etexts 
activity Ed asked if text to speech with highlighting would be 
supported.  I was reluctant to commit to that at the time, thinking it 
would be too difficult.  It turned out to be both easier and more 
difficult than I thought it would be, but I have released version 4 of 
the activity which now supports TTS with the words highlighted as they 
are spoken.

The code could be improved, no doubt.  I am fairly new to Python 
programming.  But I think trying out this Activity could give you some 
idea of what to expect if you attempt to incorporate TTS as part of the 
Sugar interface.

1).  Speech-dispatcher needs to run in a separate thread from the GTK 
event loop, otherwise the callbacks needed to highlight words won't be 
received.
2).  To get the callbacks as each word is spoken you need to format the 
text to be spoken as an XML document with tags *before* each word.  My 
code assumes that words are separated by whitespace, which works for 
many languages but not all of them.  I know Sanskrit doesn't work that 
way, for instance.
3).  Espeak does not allways do a callback for each word, and there is 
no obvious reason why any given word would be skipped.  I understand 
that Festival works better, but I haven't tried it.  At the suggestion 
of Hynek Hanke of the speech-dispatcher project I made the tag ids for 
each tag correspond to the word number in the document.  In this way I 
can get the tag id in the callback and always highlight the correct word 
even if occasionally words are skipped over by espeak.
4).  Pausing and resuming speech doesn't work.  No idea why.
5).  The instructions for setting up speech-dispatcher on the wiki are 
obsolete.  You cannot use espeak-generic module with speech-dispatcher 
and get callbacks.  You need to use the normal espeak module.  When you 
try to use the normal espeak module with the current RPMs 
speech-dispatcher complains of a missing library.  So if you want to try 
my Activity you'll need to use sugar-jhbuild with speech-dispatcher 
installed and configured to use espeak.

Hemant Goyal is working on creating RPMs for speech-dispatcher and will 
be updating the instructions on the wiki.

The Activity page is: http://wiki.laptop.org/go/Read_Etexts

James Simmons