TweetFollow Us on Twitter

Feb 00 Getting Started

Volume Number: 16 (2000)
Issue Number: 2
Column Tag: Getting Started

Speech Channels

by Dan Parks Sydow

Getting a speech-capable program ready for the use of different voices

In last month's Getting Started article we started in on the topic of speech in Macintosh programs. There you saw how your program can verify that the user's Mac is able to output speech, and you saw how your program can use the SpeakString() function to speak the text of one string. That was a good start, but if your program is to make good use of speech there are a couple of other speech-related issues to cover. You'll want your program to have the ability to speak more than a single string (without having to repeatedly call SpeakString()). This month we see how that can be done. You'll also want to give your program the power to speak in different voices. In last month's code we relied on the default voice - whatever voice is currently set for use on the user's machine. But the user has a wealth of different voices stored on his or her Mac - and your program can make use of any one of them! This month we'll see how to make use of speech channels. An application-allocated speech channel is a prerequisite for speaking in a different voice - so armed with this new speech channel information you'll be ready for next month's Getting Started article where we wrap up the topic of speech by creating an application that speaks in different voices.

Speech Basics Review

It's the Speech Manager - along with a speech synthesizer (that's a part of the Mac system software), the Sound Manager, and a Mac's audio hardware - that makes speech possible. If a Mac program is to speak, it should include the Speech.h universal header file to ensure that the compiler recognizes the speech-related Toolbox functions.

#include	<Speech.h>

Before attempting to speak, your program should verify that the user's machine will be able to output the sound (refer to last month's article if you need an explanation of the following snippet).

OSErr	err;
long		response;
long		mask;

err = Gestalt( gestaltSpeechAttr, &response );
if ( err != noErr )
	DoError( "\pError calling Gestalt" );

mask = 1 << gestaltSpeechMgrPresent;	
if ( response & mask == 0 )
 	DoError( "\pSpeech Manager not present " );

To speak a single string of text, use the SpeakString() function. Pass this function a Pascal-formatted string and SpeakString() turns the characters that make up the string into speech that emits from the user's Mac. Follow a call to SpeakString() with repeated calls to SpeechBusy() to ensure that time is provided for the full text of the string to be spoken.

OSErr	err;

err = SpeakString( "\pThis is a test." );
if ( err != noErr )
	DoError( "\pError attempting to speak a phrase" );   
while ( SpeechBusy() == true )
	;

Speech Channels

Whenever a Mac program speaks, a speech channel is involved. A speech channel is a data structure that holds descriptive information about speech that is to "pass through" that specific channel. The most important property that the channel keeps track of is the voice to use. If you want your program to speak in two different voices (perhaps a conversation between two people is going on), then you'd create two speech channels - each channel specifying a different voice. Each time your program speaks, you'd designate which channel is used, basing the decision on which voice is appropriate for the words that are about to be spoken.

Last month you learned about SpeakString() - the easy-to-use Toolbox function that speaks the text comprising a single string. In last month's article we didn't need to cover speech channels because when a call is made to SpeakString(), the Speech Manager takes care of the allocation of a speech channel. The Speech Manager than uses that channel to speak, and disposes of that same channel when speaking has completed. Because the Speech Manager takes care of all this behind the scenes, SpeakString() is very simple to use. There's a drawback to using SpeakString() though - the programmer lacks control of the speech channel. Because of this, a specific voice can't be selected. Instead, SpeakString() always uses the system default voice. Here you'll see how to create a new speech channel and then use a different Toolbox function - SpeakText() - to specify that this new channel be used when your program speaks.

Use the Toolbox function NewSpeechChannel() to create a new speech channel. This routine allocates memory for a SpeechChannelRecord. This is the data structure that holds information about a speech channel. NewSpeechChannel() finishes by returning to your program a SpeechChannel - a pointer to the new speech channel record.

SpeechChannel	channel;
OSErr					err;

err = NewSpeechChannel( nil, &channel );	

The first NewSpeechChannel() argument is a pointer to a voice specification data structure. As you'll see in next month's Getting Started article, this data structure corresponds to the voice that is to be used for speech generated through this one speech channel. To simply use the system default voice, pass nil as the first argument (as shown here).

The second argument is the address of a SpeechChannel - a data structure that holds the information about a speech channel. After NewSpeechChannel() allocates the speech channel record, this variable references the new record.

The Toolbox should have no problem allocating a new speech channel, but you'll want to prepare for the worst. If NewSpeechChannel() returns an OSErr value other than noErr, you can use some standard error-catching routine like our own DoError(), or you can opt to call the Toolbox function DisposeSpeechChannel() to dispose of the problematic channel yourself. You might also want to set the SpeechChannel variable to nil to indicate to your program that the variable doesn't hold a valid reference to a speech channel.

if ( err != noErr )
{
	err = DisposeSpeechChannel( channel );
	channel = nil;
}

Your primary use of a speech channel will be in calls to the Toolbox function SpeakText(). Unlike SpeakString(), which accepts just a string of text to speak, SpeakText() accepts a speech channel and a buffer of text to speak. Here's a typical call to SpeakText():

OSErr	err;
Str255	str = "\pHere's a test of SpeakText.";

err = SpeakText( channel, (Ptr)(str + 1), str[0] );
if ( err != noErr )
	DoError( "\pError attempting to speak a phrase" );

while ( SpeechBusy() == true ) 
	;

The first SpeakText() argument is a speech channel. Here we aren't making good use of the speech channel - but next month, we will.

The second argument is a pointer to the area of memory that holds the text to speak. In the above example I've used a string to represent the text. Your program could also append strings together in a buffer, or read text from an external file to a buffer. A variable of type Str255 uses its first byte to hold the length (in bytes) of the string, and the remaining bytes to hold the characters that make up the string. If we just used str as the second argument, SpeakText() would attempt to start speaking using the value in the first byte of str - which happens to be a number. By using str + 1, we tell SpeakText() to move to the second byte of str and start speaking from there. Finally, because SpeakText() requires a generic pointer to a buffer, the Str255 variable needs to be typecast to type Ptr. Collectively (Ptr)(str + 1) make up the second argument.

The third SpeakText() argument is the number of bytes that should be used from the buffer. In the case of a Str255 variable, the number of bytes making up the string is held in the first byte of the variable. So the first element (byte [0]) in the Str255 variable represents the number of buffer bytes holding characters to speak.

As you did for SpeakString(), end with repeated calls to SpeechBusy() to provide ample time for the Mac to speak the words in the SpeakText() buffer.

SpeechChan

This month's program is SpeechChan. This simple, non-menu-driven program provides a working example of how to create and make use of a sound channel. When run, SpeechChan speaks the phrase "We've successfully opened a speech channel". After speaking those words the program quits.

Creating the SpeechChan Resources

Start by creating a new folder named SpeechChan in your CodeWarrior development folder. Launch ResEdit and create a new resource file named SpeechChan.rsrc. Specify that the SpeechChan folder serve as the resource file's destination. This resource file will hold only two resources. As shown in Figure 1, you'll need just an ALRT and a DITL resource for this project.


Figure 1. The SpeechChan resources.

The resource file will hold one alert resource - ALRT 128. Corresponding to this ALRT is DITL 128. Together these two resources define the program's error-handling alert. If your version of the SpeechChan program doesn't commit any serious errors, then the program won't make use of these resources.

Creating the SpeechChan Project

Create a new project by starting up CodeWarrior and choosing New Project from the File menu. Use the MacOS:C_C++:MacOS Toolbox:MacOS Toolbox Multi-Target project stationary for the new project. Uncheck the Create Folder check box before clicking the OK button. Name the project SpeechChan.mcp, and specify that the project's destination be the existing SpeechChan folder.

Now add the SpeechChan.rsrc resource file to the project. Remove the SillyBalls.rsrc file. The ANSI Libraries folder can stay or go - as is the case for most of our example projects, we aren't making use of any ANSI C libraries, so you can remove them from the project if you wish.

If you plan on making a PowerPC version (or fat version) of the SpeechChan program, be sure to add the SpeechLib library to the PowerPC targets of your project. As mentioned last month, you'll want to choose Add Files from the Project menu and work your way over to this library. You'll find it in the Metrowerks CodeWarrior:MacOS Support:Libraries:MacOS Common folder. If you can't find the library in that folder, use Sherlock to search your hard drive for it. When you add the library to the project CodeWarrior displays a dialog box asking you which targets to add the library to. Check the two PPC targets. In Figure 2 you see how your project will look with the SpeechLib library added to it.


Figure 2. The SpeechChan project.

Now create a new source code window by choosing New from the File menu.. Save the window, giving it the name SpeechChan.c. Choose Add Window from the Project menu to add the new empty file to the project. Remove the SillyBalls.c placeholder file from the project window. At this point you're ready to type in the source code.

If you want to save yourself a little typing, connect to the Internet and visit MacTech's ftp site at ftp://ftp.mactech.com/src/mactech/volume16_2000/16.02.sit. There you'll find the SpeechChan source code file available for downloading.

Walking Through the Source Code

SpeechChan.c starts with the inclusion of the Speech.h file. If you compile the source file and you receive a number of undefined function errors, then you most certainly forgot to include this universal header file.

/********************** includes *********************/

#include	<Speech.h>

After the #include comes a single constant. The constant kALRTResID holds the ID of the ALRT resource used to define the error-handling alert.

/********************* constants *********************/

#define		kALRTResID						128 

Next come the program's function prototypes.

/********************* functions *********************/

void						ToolBoxInit( void );
SpeechChannel	OpenOneSpeechChannel( void );
void						DoError( Str255 errorString );

The main() function of SpeechChan starts with the declaration of several variables. The first three variables, err, response, and mask, are used in the determination of whether speech generation is possible on the user's Mac. The other two variables, str and channel, are used in the generation of speech.

/********************** main *************************/

void		main( void )
{ 
	OSErr	err;
	long		response;
	long		mask;
	Str255	str ="\pWe've successfully opened a speech channel.";
	SpeechChannel	channel;

After the Toolbox is initialized the previously discussed speech-related tests are made:

	ToolBoxInit();

	err = Gestalt( gestaltSpeechAttr, &response );
	if ( err != noErr )
		DoError( "\pError calling Gestalt" );

	mask = 1 << gestaltSpeechMgrPresent;	
	if ( response & mask == 0 )
		DoError( "\pSpeech Manager not present " );

Now we get down to business. First, a speech channel is allocated and a reference to it is saved in local variable channel. Note that this local variable could have been a global variable - the choice is dependent on your programming style. The application-defined function OpenOneSpeechChannel() is described just ahead.

	channel = OpenOneSpeechChannel();

	if ( channel == nil )

		DoError( "\pError opening a speech channel" );

With a valid speech channel, we can make a call to SpeakText(). The arguments here match the ones described in this article's previous SpeakText() example snippet.

	err = SpeakText( channel, (Ptr)(str + 1), str[0] );
	if ( err != noErr )
		DoError( "\pError attempting to speak a phrase" );

	while ( SpeechBusy() == true ) 
		;

When we're finished speaking, we dispose of the speech channel. Unlike a call to SpeakString(), SpeakText() required our efforts in creating the speech channel. We made it, so we need to throw it out.

	err = DisposeSpeechChannel( channel );
	if ( err != noErr )
		DoError( "\pError disposing speech channel" );
}

ToolBoxInit() remains the same as previous versions.

/******************** ToolBoxInit ********************/

void		ToolBoxInit( void )
{
	InitGraf( &qd.thePort );
	InitFonts();
	InitWindows();
	InitMenus();
	TEInit();
	InitDialogs( nil );
	InitCursor();
}

OpenOneSpeechChannel() calls NewSpeechChannel() to create a new speech channel. The OpenOneSpeechChannel() routine is called from main(), so that's where the reference to the newly created channel gets returned.

/*************** OpenOneSpeechChannel ****************/

SpeechChannel OpenOneSpeechChannel( void )
{
  SpeechChannel channel;  
  OSErr     err;

  err = NewSpeechChannel( nil, &channel );

  if ( err != noErr )
  {
   err = DisposeSpeechChannel( channel );
   channel = nil;
  }

  return ( channel );
}

DoError() is unchanged from prior versions. A call to this function results in the posting of an alert that holds an error message. After the alert is dismissed the program ends.

/********************** DoError **********************/

void		DoError( Str255 errorString )
{
	ParamText( errorString, "\p", "\p", "\p" );

	StopAlert( kALRTResID, nil );

	ExitToShell();
}

Running SpeechChan

Run SpeechChan by choosing Run from CodeWarrior's Project menu. After the code is compiled, CodeWarrior runs the program. After the program speaks a single phrase, the program ends. If the program successfully builds and appears to run and quit without speaking, then there's a good chance you have the speaker volume on your Mac set to 0!

Till Next Month...

Last month you saw how your program can speak the text in a single string. Here you saw how your program can speak a greater amount of text by way of a buffer. You also saw how to create a speech channel. Next month we'll wrap up the topic of speech by discussing how you can specify which voice - male, female, young, old, even robotic - you want your program to speak in. Until then you can study up on speech generation by looking at the Sound volume of Inside Macintosh...

 
AAPL
$116.47
Apple Inc.
+0.16
MSFT
$47.98
Microsoft Corpora
-0.72
GOOG
$537.50
Google Inc.
+2.67

MacTech Search:
Community Search:

Software Updates via MacUpdate

Cobook 3.0.7 - Intelligent address book....
Cobook Contacts is an intuitive, engaging address book. Solve the problem of contact management with Cobook Contacts and its simple interface and powerful syncing and integration possibilities.... Read more
StatsBar 1.9 - Monitor system processes...
StatsBar gives you a comprehensive and detailed analysis of the following areas of your Mac: CPU usage Memory usage Disk usage Network and bandwidth usage Battery power and health (MacBooks only)... Read more
Cyberduck 4.6 - FTP and SFTP browser. (F...
Cyberduck is a robust FTP/FTP-TLS/SFTP browser for the Mac whose lack of visual clutter and cleverly intuitive features make it easy to use. Support for external editors and system technologies such... Read more
Maya 2015 - Professional 3D modeling and...
Maya is an award-winning software and powerful, integrated 3D modeling, animation, visual effects, and rendering solution. Because Maya is based on an open architecture, all your work can be scripted... Read more
Evernote 6.0.1 - Create searchable notes...
Evernote allows you to easily capture information in any environment using whatever device or platform you find most convenient, and makes this information accessible and searchable at anytime, from... Read more
calibre 2.11 - Complete e-library manage...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital... Read more
Herald 5.0.1 - Notification plugin for M...
Note: Versions 2.1.3 (for OS X 10.7), 3.0.6 (for OS X 10.8), and 4.0.8 (for OS X 10.9) are no longer supported by the developer. Herald is a notification plugin for Mail.app, Apple's Mac OS X email... Read more
Firetask 3.7 - Innovative task managemen...
Firetask uniquely combines the advantages of classical priority-and-due-date-based task management with GTD. Stay focused and on top of your commitments - Firetask's "Today" view shows all relevant... Read more
TechTool Pro 7.0.6 - Hard drive and syst...
TechTool Pro is now 7, and this is the most advanced version of the acclaimed Macintosh troubleshooting utility created in its 20-year history. Micromat has redeveloped TechTool Pro 7 to be fully 64... Read more
PhotoDesk 3.0.1 - Instagram client for p...
PhotoDesk lets you view, like, comment, and download Instagram pictures/videos! (NO Uploads! / Image Posting! Instagram forbids that! AND you *need* an *existing* Instagram account). But you can do... Read more

Latest Forum Discussions

See All

Ubisoft Gives Everyone Two New Ways to E...
Ubisoft Gives Everyone Two New Ways to Earn In-Game Stuff for Far Cry 4 Posted by Jessica Fisher on November 21st, 2014 [ permalink ] | Read more »
Golfinity – Tips, Tricks, Strategies, an...
Dig this: Would you like to know what we thought of being an infinite golfer? Check out our Golfinity review! Golfinity offers unlimited ways to test your skills at golf. Here are a few ways to make sure your score doesn’t get too high and your... | Read more »
Dark Hearts, The Sequel to Haunting Meli...
Dark Hearts, The Sequel to Haunting Melissa, is Available Now Posted by Jessica Fisher on November 21st, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Meowza! Toyze Brings Talking Tom to Life...
Meowza! | Read more »
Square Enix Announces New Tactical RPG f...
Square Enix Announces New Tactical RPG for Mobile, Heavenstrike Rivals. Posted by Jessica Fisher on November 21st, 2014 [ permalink ] With their epic stories and gorgeous graphics, | Read more »
Quest for Revenge (Games)
Quest for Revenge 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: The great Kingdom of the west has fallen. The gods ignore the prayers of the desperate. A dark warlord has extinguished... | Read more »
Threadz is a New Writing Adventure for Y...
Threadz is a New Writing Adventure for You and Your Friends Posted by Jessica Fisher on November 21st, 2014 [ permalink ] In the tradition of round-robin storytelling, | Read more »
SteelSeries Stratus XL Hardware Review
Made by: SteelSeries Price: $59.99 Hardware/iOS Integration Rating: 4 out of 5 stars Usability Rating: 4.5 out of 5 stars Reuse Value Rating: 4.25 out of 5 stars Build Quality Rating: 4.5 out of 5 stars Overall Rating: 4.31 out of 5 stars | Read more »
ACDSee (Photography)
ACDSee 1.0.0 Device: iOS iPhone Category: Photography Price: $1.99, Version: 1.0.0 (iTunes) Description: Capture, perfect, and share your photos with ACDSee. The ACDSee iPhone app combines an innovative camera, a powerful photo... | Read more »
ProTube for YouTube (Entertainment)
ProTube for YouTube 2.0.2 Device: iOS Universal Category: Entertainment Price: $1.99, Version: 2.0.2 (iTunes) Description: ProTube is the ultimate, fully featured YouTube app. With it's highly polished design, ProTube offers ad-free... | Read more »

Price Scanner via MacPrices.net

15″ 2.2GHz Retina MacBook Pro on sale for $17...
 B&H Photo has the 2014 15″ 2.2GHz Retina MacBook Pro on sale today for $1749. Shipping is free, and B&H charges NY sales tax only. B&H will also include free copies of Parallels Desktop... Read more
27-inch 3.5GHz 5K iMac in stock today and on...
 B&H Photo has the new 27″ 3.5GHz 5K iMac in stock today and on sale for $2299 including free shipping plus NY sales tax only. Their price is $200 off MSRP, and it’s the lowest price available... Read more
21-inch 1.4GHz iMac on sale for $979, save $1...
B&H Photo has the new 21″ 1.4GHz iMac on sale for $979.99 including free shipping plus NY sales tax only. Their price is $120 off MSRP. B&H will also include free copies of Parallels Desktop... Read more
13-inch 1.4GHz/256GB MacBook Air on sale for...
B&H Photo has lowered their price on the 13″ 1.4GHz/256GB MacBook Air to $1059.99 including free shipping plus NY sales tax only. Their price is $140 off MSRP, and it’s the lowest price for this... Read more
Save up to $400 with Apple refurbished 2014 1...
The Apple Store has restocked Apple Certified Refurbished 2014 15″ Retina MacBook Pros for up to $400 off the cost of new models. An Apple one-year warranty is included with each model, and shipping... Read more
New 13-inch 1.4GHz MacBook Air on sale for $8...
 Adorama has the 2014 13″ 1.4GHz/128GB MacBook Air on sale for $899.99 including free shipping plus NY & NJ tax only. Their price is $100 off MSRP. B&H Photo has the 13″ 1.4GHz/128GB MacBook... Read more
Apple Expected to Reverse Nine-Month Tablet S...
Apple and Samsung combined accounted for 62 percent of the nearly 36 million branded tablets shipped in 3Q 2014, according to early vendor shipment share estimates from market intelligence firm ABI... Read more
Stratos: 30 Percent of US Smartphone Owners t...
Stratos, Inc., creator of the Bluetooth Connected Card Platform, has announced results from its 2014 Holiday Mobile Payments Survey. The consumer survey found that nearly one out of three (30 percent... Read more
2014 1.4GHz Mac mini on sale for $449, save $...
 B&H Photo has lowered their price on the new 1.4GHz Mac mini to $449.99 including free shipping plus NY tax only. Their price is $50 off MSRP, and it’s the lowest price available for this new... Read more
Check Apple prices on any device with the iTr...
MacPrices is proud to offer readers a free iOS app (iPhones, iPads, & iPod touch) and Android app (Google Play and Amazon App Store) called iTracx, which allows you to glance at today’s lowest... Read more

Jobs Board

*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Solutions Consultant (ASC)- Retail S...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
Project Manager, *Apple* Financial Services...
**Job Summary** Apple Financial Services (AFS) offers consumers, businesses and educational institutions ways to finance Apple purchases. We work with national and Read more
*Apple* Store Leader Program - College Gradu...
Job Description: Job Summary As an Apple Store Leader Program agent, you can continue your education as you major in the art of leadership at the Apple Store. You'll Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.