SAPI
What is it
SAPI stands for Speech Application Programming Interface, a Microsoft Windows API used to perform text-to-speech (TTS).
Use with FreePascal
Lazarus/FreePascal can use this interface to perform TTS. Source: forum post: [1]
On Windows Vista and above, you will run in trouble with the FPU interrupt mask (see [2]). The code dealing with SavedCW is meant to work around this.
uses
...,comobj;
var
SavedCW: Word;
SpVoice: Variant;
begin
SpVoice := CreateOleObject('SAPI.SpVoice');
// Change FPU interrupt mask to avoid SIGFPE exceptions
SavedCW := Get8087CW;
try
Set8087CW(SavedCW or $4);
SpVoice.Speak('hi', 0);
finally
// Restore FPU mask
Set8087CW(SavedCW);
end;
For the options available with SpVoice.Speak and other SpVoice methods see http://msdn.microsoft.com/en-us/library/ms723609(v=vs.85).aspx.
- WARNING The Ole object created in above snippet will be destroyed automatically when the SpVoice variant goes out of scope. For larger texts the use of the asynchronous mode allows to keep your application reactive while speak is running. In that case it is especially important to control carefully the lifetime of the object and store it in a global or class variable. Destroying the object while speak is still running can cause crashes.
Changing the FPU interrupt mask can be done at any moment before loading the ole object and if your application is not using any floating point arithmetic there is no need to reset the FPU interrupt mask to its original value.
Linux/Unix alternatives
On Linux/Unix, there are some command line Text To Speech engines, that may also offer access via APIs. An example is the festival engine.
See Linux_Programming_Tips#Perform_text-to-speech_.28TTS.29_or_how_to_let_my_computer_speak
OSX alternatives
OSX has system wide text to speech functionality built in: VoiceOver. See LCL_Accessibility#Mac_OS_X_VoiceOver See here for code for using the say command to perform TTS: [3]