libs-gui/Tools/speech/FliteSpeechEngine.m

#import "GSSpeechEngine.h"
#include <flite/flite.h>

cst_voice *register_cmu_us_kal();

/**
 * Implementation of a speech engine using flite.  This should be the default
 * for resource-constrained platforms.
 */
@interface FliteSpeechEngine : GSSpeechEngine {
	/** The audio device used for sound output. */
	cst_audiodev *ad;
	/** The current voice.  Only one supported at the moment. */
	cst_voice *v;
	/** Flag set to tell the playback thread to exit. */
	volatile BOOL shouldEndSpeaking;
	/** Flag indicating whether the engine is currently speaking. */
	volatile BOOL isSpeaking;
}
@end

@implementation FliteSpeechEngine
+ (void)initialize
{
	flite_init();

}
- (id)init
{
	if (nil == (self = [super init])) { return nil; }

	// Only one voice supported by flite unless others are compiled in.
	v = register_cmu_us_kal();
	if (NULL == v)
	{
		[self release];
		return nil;
	}

	// Each wave should be the same format.
	cst_wave *w = flite_text_to_wave("test", v);
	ad = audio_open(w->sample_rate, w->num_channels, CST_AUDIO_LINEAR16);
	delete_wave(w);
	if (NULL == ad)
	{
		[self release];
		return nil;
	}
	return self;
}
- (void)sayString: (NSArray*)args
{
	id pool = [NSAutoreleasePool new];
	NSString *aString = [args objectAtIndex: 0];
	int i,n,r;
	int num_shorts;
	BOOL didFinish = YES;
	cst_wave *w = flite_text_to_wave([aString UTF8String], v);

	num_shorts = w->num_samples * w->num_channels;
	for (i=0; i < num_shorts; i += r/2)
	{
		if (num_shorts > i+CST_AUDIOBUFFSIZE)
		{
			n = CST_AUDIOBUFFSIZE;
		}
		else
		{
			n = num_shorts-i;
		}
		r = audio_write(ad, &w->samples[i], n*2);
		if (shouldEndSpeaking)
		{
			didFinish = NO;
			break;
		}
	}
	isSpeaking = NO;
	NS_DURING
	[[args objectAtIndex: 1] didFinishSpeaking: didFinish];
	NS_HANDLER
	NS_ENDHANDLER
	[args release];
	[pool release];
	delete_wave(w);
}
- (void)startSpeaking: (NSString*)aString notifyWhenDone: (id)aDelegate
{
	[[[aDelegate delegate] connectionForProxy] enableMultipleThreads];
	NSArray *arg = [[NSArray alloc] initWithObjects: aString, aDelegate, nil];
	shouldEndSpeaking = NO;
	isSpeaking = YES;
	[NSThread detachNewThreadSelector: @selector(sayString:)
							 toTarget: self
						   withObject: arg];

}
- (BOOL)isSpeaking
{
	return isSpeaking;
}
- (void)stopSpeaking
{
	shouldEndSpeaking = YES;
	// Spin until the other thread has died.
	while (isSpeaking) {}
}
- (void)dealloc
{
	[self stopSpeaking];
	audio_close(ad);
	[super dealloc];
}
@end

@implementation GSSpeechEngine (Flite)
+ (GSSpeechEngine*)defaultSpeechEngine
{
	return [[[FliteSpeechEngine alloc] init] autorelease];
}
@end