3. General Rules

SSIP communicates with the clients through a defined set of text commands, in the usual manner for common Internet protocols. The characters sent through the Speech Synthesis Interface Protocol are encoded using the UTF-8 encoding.

Each SSIP command, unless specified otherwise, consists of exactly one line. The line is sent in the following format:

command arg ...

where command is a case insensitive command name and args are its arguments separated by spaces. The command arguments which come from a defined set of values are case insensitive as well. The number of arguments is dependent on the particular command and there can be commands having no arguments.

All lines of SSIP input and output must be ended with a pair of carriage return and line feed characters, in that order.

When you connect to Speech Server, you should at least set your client name, through the SET SELF CLIENT_NAME command (see section Parameter Setting). This is important to get a proper identification of your client -- to allow managing it from the control center application and to identify it in a message history browser. You might want to set other connection parameters as well. Look for more details in Parameter Setting.

An SSIP connection is preferably closed by issuing the QUIT command, see Other Commands.

SSIP is a synchronous protocol -- you send commands and only after a complete response from SSIP arrives back are you allowed to send the next command. Usually, the SSIP connection remains open during the whole run of the particular client application. If you close the connection and open it again, you must set all the previously set parameters again, SSIP doesn't store session parameters between connections.

The protocol allows you to perform commands influencing other currently connected or previously connected clients. This allows you to write a control application managing or browsing all the messages received by the current Speech Server process. The mechanism is completely relaxed, there are no restrictions on managing some aspects of sound output for other users, however, there is a mechanism to prevent one user from seeing history messages of another user.

Some of the commands (Controlling Speech Output and Parameter Setting) take an argument in the form:

        { id | all | self }

where the value can be the id of the connection the command should be performed on (a positive number), the string all to act on all clients of this server or self to act on the connection itself. Unless you are writing a special client for managing Speech Server or unless you have specific needs, you should only use the self value for this argument.

Not all parameter setting commands may receive all kinds of the first parameter defined above, for instance, some of them may receive only self.

SSIP replies have the following format:

ccc-line 1
ccc-line 2
...
ccc-line n-1
ddd line n

where n is a positive integer, and ccc and ddd are three-digit long numeric codes identifying the result of the command. The last line determines the overall result of the command. The result code is followed by an English message describing the result of the action in a human readable form.

This document was generated by Hynek Hanke on July, 31 2008 using texi2html 1.76.