SpeakText
Begins speaking a buffer of text.
Declaration
OSErr SpeakText(SpeechChannel chan, const void *textBuf, unsigned long textBytes);Parameters
- chan:
The speech channel through which speech is to be spoken.
- textBuf:
A pointer to the first byte of text to spoken.
- textBytes:
The number of bytes of text to spoken.
Return Value
A resultcode. See Result Codes.
Discussion
Like SpeakString,the SpeakText functionalso generates speech, but through a speech channel through whichyou can exert control over the generated speech.
The SpeakText functionconverts the text stream specified by the textBuf and textBytes parametersinto speech using the voice and control settings for the speechchannel chan, which shouldbe created with the NewSpeechChannel function.The speech is generated asynchronously. This means that controlis returned to your application before the speech has finished (andprobably even before it has begun). The maximum length of the text bufferthat can be spoken is limited only by the available RAM.
If SpeakText iscalled while the channel is currently busy speaking the contentsof a prior text buffer, it immediately stops speaking from the priorbuffer and begins speaking from the new text buffer as soon as possible.If you pass a zero-length string (or, in C, a null pointer)to SpeakText, the SpeechSynthesis Manager stops all speech currently being synthesized bythe speech channel specified in the chan parameterwithout generating additional speech.
The text buffer must be locked in memory and must not movewhile the Speech Synthesis Manager processes it. This buffer isread at interrupt time, and moving it could cause a system crash.If your application defines a text-done callback function, thenit can move the text buffer or dispose of it once the callback functionis executed.