[g-a-devel]Re: New revision of GNOME Speech IDL

[Marc Mulcahy <marc mulcahy sun com>]

Hi Paul,

Going through mail and wasn't sure whether I had adequately 
responded/filled you in on what's happening with GNOME Speech, so either 
sorry this is so late or sorry for the repeat, not sure which.

We're preparing version 0.2 of GNOME Speech, based on the API you reviewed 
on the 9th of October, to ship with Gnopernicus, since it requires some 
sort of speech service.  I have one driver written for IBM's Linux Viavoice 
TTS kit, and am working on a FreeTTS driver for the 0.2 stuff now.  But 
that will be pretty much all we do on the 0.2 version.

Rich Burridge has been working on converting the JSAPI class files to GNOME 
IDL as an initial proposal for the GNOME Speech 1.0 API, based on 
JSAPI.  So, it seems that the best use of future effort/review will be on 
the 1.0 track, so that's where I'll be focusing once this work on the 0.2 
stuff for Gnopernicus is finished.

Please don't hesitate to send feedback/questions.

I've formed the gnome-speech-dev sun com alias, to which you are a member.

Regards,

Marc


At 08:04 AM 10/9/2002 -0400, Paul Lamere wrote:
> Marc:
>
> Thanks for sending along the new IDL for gnome-speech. I've taken a look 
> at and have made some comments, which are attached.
>
>
> Paul
>
>
>
> *** Comment (0) - Overall
>     It would be nice to have the API behavior documented a bit better
>     (e.g. what does the boolean return from 'stop' mean?)
>
> *** Comment (1) - GNOME_Speech_SynthesizerDriver:voice_language
>
>     Since voice_language is an enum:
>
>       enum voice_language {
>         language_english,
>         language_german
>       };
>
>     Does this mean that a new version of gnome-speech needs to be
>     generated to support a new language?    How does Gnome represent a
>     locale? If Gnome doesn't have a standard way of representing a locale,
>     then perhaps ISO country/language codes should be used.  This would
>     allow for speech engines to support new languages without any changes
>     to the gnome-speech API.
>
> *** Comment (2) - GNOME_Speech_SynthesizerDriver:voice_info
>
>     VoiceInfo should probably be expanded to include:
>        * age - the age of the speaker.
>        * style - the style of the voice. Allows for further
>                  distinguishing voices. For instance:
>                  "business", "casual" could be styles supported by a
>                  particular engine.
>
>
> *** Comment (3) - GNOME_Speech_SynthesizerDriver
>
>     Is it possible for a system to have more than one vendor TTS engine
>     installed? If it is possible, it is not clear to me how an application
>     would chose one vendor TTS engine over another with this API.
>
>     How does an application get an instance of a  SynthesisDriver?
>
> *** Comment (4) - GNOME_Speech_SynthesizerDriver
>
>     In a typical system, would there be a single running instance of a TTS
>     engine that all speech applications would share, or would each
>     application have its own instance?   How can speech applications
>     coordinate their output with each other?   For instance, a book reader
>     application may queue up an hours worth of text to be spoken.  If a
>     speech-enabled calendar application needs to announce an appointment
>     would it:
>
>        a) Interrupt the book reader
>        b) Speak over the book reader
>        c) Wait until the book was finished.
>
>     How is this coordination managed in the API?
>
> *** Comment (5) - GNOME_Speech_Speaker
>
>    - Speaker: Needs a 'pause' method
>    - Speaker: Needs a 'resume' method
>    - Speaker: Needs a 'getVoiceInfo' method.
>    - Perhaps add a 'sayURL' that takes a URL pointing to marked-up
>      text.
>    - Perhaps add a 'sayPlainText' that speaks text with no markup.
>
>    - Does 'say' return immediately after queueing up text?  I presume
>      that since there is a 'wait' call, that indeed it does. If an
>      application has queued up ten strings to be spoken, does 'stop'
>      stop the speaking of the first string in the queue or all strings
>      in the queue. Likewise, does 'wait' wait for the queue to be empty, or
>      for the current (head of the queue) text to be spoken. Generally
>      speaking, if there is a TTS output queue, an application will
>      need some methods to allow fine grained manipulation the queue.
>
>
> *** Comment (6) Vocabulary management
>    - How does an application add new words/pronunciations to the TTS
>      dictionary?
>
>
> *** Comment (7) callbacks
>     It is unclear from the API when callbacks are generated. There are
>     a number of interesting speech events that an application may want
>     to receive callbacks for:
>
>        - utterance started
>        - utterance ended
>        - word started
>        - word ended
>        - phoneme started
>        - marker reached
>        - utterance cancelled
>        - utterance paused
>        - utterance resumed
>
>     I suggest adding an event type to the SpeechCallback notify that
>     can be used to indicate the type of event
>
>     Some applications may want to see all of these events, while some
>     won't want to see any.  Since some of the events can add some
>     overhead to the speech engine, it may be useful to allow an
>     application to register callbacks for specific event types.
>
>     The 'notify' method gets a 'text_id' as a long type. I presume
>     this is the long value that is returned by 'say'.  I think this is
>     a bit awkward for an application. If an application wants access
>     to the text that is currently being output it will have to store
>     all the text, associate the text with the id and remember to clean
>     it all up afterwards. I would prefer to see the SpeechCallBack
>     'notify' method get a struct that includes a reference to the
>     current string being output.
>
> *** Comment (8) Parameters -
>     How does setting parameters interact with text that is queued to
>     be spoken?  If an application queues ten strings to be spoken and
>     then calls 'setParameterValue' to change a property such as the
>     speaking volume, when does the change take place? Some options:
>         a) Immediately (in the middle of speaking the current text)
>         b) After the current utterance is finished
>         c) After all the items currently in the queue have been
>         spoken.
>
>     Note that some engines will not be able to change some parameters
>     in mid-utterance.
>
> *** Comment (9) Parameters -
>         What is the intended use of the 'enumerated' field of the
>         Parameter struct?
>
>         What does 'getParameterValue' return if a request is made for
>         an unknown parameter?
>
>         What does 'getParameterValueDescription' do?
>
>         Does the 'setParameterValue' return value indicate the
>         success/failure of the set?
>
>         I'm not sure if the 'double' type is appropriate for all
>         parameters.
>
>
> *** Comment (10) Global Parameters -
>
>     If I have a number of speech applications do I need to set
>     properties for each application, or is there a way that I can
>     set parameters globally and have each application use these
>     global settings.  For instance, I can imagine that a user may
>     want to globally increase the speaking rate for all
>     applications.  Perhaps a mechanism akin to the X resources
>     would be appropriate.
>
> *** Comment (11) Audio Redirection -
>    Is there anyway for an application to redirect audio?
>
> *** Comment (12) releaseSpeaker? -
>
>     When an application is done with a 'Speaker' that was created with
>     SynthesisDriver::createSpeaker, how does the application release it?