Open Source Toolkit Documentation:

The MITRE TrueTalk Server

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The MITRE TrueTalk server provides a Communicator-compliant interface to TrueTalk 2.0.

Status
Usage
Message set
Messages issued
Known bugs

Status

History and plans

Stable implementation from Galaxy Communicator 3.2 distribution. This server is no longer supported because TrueTalk was a product, and because the manufacturer, Entropic, was purchased by Microsoft and TrueTalk was removed from circulation.

Version history

1.0 on 1/25/02

Usage

In order to run this server, you must have the TrueTalk tts server running somewhere:

% %TT_BASE/bin/tts -server

Command line

<OSTK_ROOT>/bin/truetalk ...

Default port

15020

Command line arguments

static char *oas[] = {
"-tts_host host", "host where the truetalk server (tts -server) is running (default: localhost)", TT_DEFAULT_ELMDHOST,
NULL
};

This server also accepts the standard server arguments. See the command-line argument parsing library in the Galaxy Communicator documentation for details.

speak_output takes a string and produces a waveform, and notifies the audio server of incoming audio.

parameter type optional depends on description/constraints

IN: :reply_string string string to be synthesized

:session_id string yes if session IDs are being used, this should be the session ID of the current session

This message returns a frame.

reinitialize sets up the TrueTalk server for the connection.

parameter type optional depends on description/constraints

IN: :encoding string yes encoding for the audio. Legal values are linear16 (16 bit PCM) or mulaw255 (8 bit mu-law). Defaults to 8-bit mu-law. The encoding names are used for consistency with the MIT audio device message handle_synth_data.

CAUTION. Although this server is configured to handle both possible encodings, at the moment only 16 bit PCM is working.

Messages issued

The synthesis server issues a message to the Hub when there are waveforms to be read and presented on the audio device. This message has the following form:

Start of speech

When the audio server detects audio input, it dispatchs a broker request for another server to read the audio, which can be claimed by the recognizer. The broker request is of the form

{c synthesis
   :broker_port <integer>
   :call_id <string: broker connection ID>
   :synth_host <string: current host>
   :synth_port <integer: value of :broker_port>
   :sample_rate 8000
   :encoding_format [ linear16 | mulaw255 ]
}

The broker server accepts either GAL_BINARY (for 8-bit mulaw) or GAL_INT_16 (for 16 bit PCM) data, as well as the following control messages of type GAL_STRING, following the MIT audio playbox control protocol:

"AUDIO_CLIENT_PLAY_START": audio is about to be sent
"AUDIO_CLIENT_PLAY_SAMPLES_DONE": no more samples will be sent (utterance is over)

Known bugs

None yet.