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...

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Google Earth 7.1.8.3036 - View and contr...
Google Earth gives you a wealth of imagery and geographic information. Explore destinations like Maui and Paris, or browse content from Wikipedia, National Geographic, and more. Google Earth combines... Read more
QuickBooks 16.1.11.1556 R12 - Financial...
QuickBooks helps you manage your business easily and efficiently. Organize your finances all in one place, track money going in and out of your business, and spot areas where you can save. Built for... Read more
FileZilla 3.24.0 - Fast and reliable FTP...
FileZilla (ported from Windows) is a fast and reliable FTP client and server with lots of useful features and an intuitive interface. Version 3.24.0: New The context menu for remote file search... Read more
Bookends 12.7.8 - Reference management a...
Bookends is a full-featured bibliography/reference and information-management system for students and professionals. Bookends uses the cloud to sync reference libraries on all the Macs you use.... Read more
Duplicate Annihilator 5.8.3 - Find and d...
Duplicate Annihilator takes on the time-consuming task of comparing the images in your iPhoto library using effective algorithms to make sure that no duplicate escapes. Duplicate Annihilator detects... Read more
BusyContacts 1.1.6 - Fast, efficient con...
BusyContacts is a contact manager for OS X that makes creating, finding, and managing contacts faster and more efficient. It brings to contact management the same power, flexibility, and sharing... Read more
MarsEdit 3.7.10 - Quick and convenient b...
MarsEdit is a blog editor for OS X that makes editing your blog like writing email, with spell-checking, drafts, multiple windows, and even AppleScript support. It works with with most blog services... Read more
BusyCal 3.1.4 - Powerful calendar app wi...
BusyCal is an award-winning desktop calendar that combines personal productivity features for individuals with powerful calendar sharing capabilities for families and workgroups. Its unique features... Read more
VirtualBox 5.1.14 - x86 virtualization s...
VirtualBox is a family of powerful x86 virtualization products for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers... Read more
Bookends 12.7.8 - Reference management a...
Bookends is a full-featured bibliography/reference and information-management system for students and professionals. Bookends uses the cloud to sync reference libraries on all the Macs you use.... Read more

Super Mario Run dashes onto Android in M...
Super Mario Run was one of the biggest mobile launches in 2016 before it was met with a lukewarm response by many. While the game itself plays a treat, it's pretty hard to swallow the steep price for the full game. With that said, Android users... | Read more »
WarFriends Beginner's Guide: How to...
Chillingo's new game, WarFriends, is finally available world wide, and so far it's a refreshing change from common mobile game trends. The game's a mix of tower defense, third person shooter, and collectible card game. There's a lot to unpack here... | Read more »
Super Gridland (Entertainment)
Super Gridland 1.0 Device: iOS Universal Category: Entertainment Price: $1.99, Version: 1.0 (iTunes) Description: Match. Build. Survive. "exquisitely tuned" - Rock Paper Shotgun No in-app purches, and no ads! | Read more »
Red's Kingdom (Games)
Red's Kingdom 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Mad King Mac has kidnapped your father and stolen your golden nut! Solve puzzles and battle goons as you explore and battle your... | Read more »
Turbo League Guide: How to tame the cont...
| Read more »
Fire Emblem: Heroes coming to Google Pla...
Nintendo gave us our first look at Fire Emblem: Heroes, the upcoming mobile Fire Emblem game the company hinted at last year. Revealed at the Fire Emblem Direct event held today, the game will condense the series' tactical RPG combat into bite-... | Read more »
ReSlice (Music)
ReSlice 1.0 Device: iOS Universal Category: Music Price: $9.99, Version: 1.0 (iTunes) Description: Audio Slice Machine Slice your audio samples with ReSlice and create flexible musical atoms which can be triggered by MIDI notes or... | Read more »
Stickman Surfer rides in with the tide t...
Stickson is back and this time he's taken up yet another extreme sport - surfing. Stickman Surfer is out this Thursday on both iOS and Android, so if you've been following the other Stickman adventures, you might be interested in picking this one... | Read more »
Z-Exemplar (Games)
Z-Exemplar 1.4 Device: iOS Universal Category: Games Price: $3.99, Version: 1.4 (iTunes) Description: | Read more »
5 dastardly difficult roguelikes like th...
Edmund McMillen's popular roguelike creation The Binding of Isaac: Rebirth has finally crawled onto mobile devices. It's a grotesque dual-stick shooter that tosses you into an endless, procedurally generated basement as you, the pitiable Isaac,... | Read more »

Price Scanner via MacPrices.net

Twelve South Releases RelaxedLeather Cases fo...
Inspired by the laid-back luxury of burnished leather boots and crafted in rich tones of taupe, herb and marsala, RelaxedLeather cases deliver smart, easy protection for the iPhone 7. Each genuine... Read more
Week’s Best Deal: New 2016 13-inch 2.0GHz Mac...
Amazon has the new 2016 13″ 2.0GHz non-Touch Bar MacBook Pros on sale for a limited time for $225 off MSRP including free shipping: - 13″ 2.0GHz MacBook Pro, Space Gray (MLL42LL/A): $1274.99 $225 off... Read more
Back in stock: Apple refurbished Mac minis fr...
Apple has Certified Refurbished Mac minis available starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: - 1.4GHz Mac mini: $419 $80 off MSRP - 2.6GHz Mac... Read more
Apple Ranked ‘Most Intimate Brand’
The top ranked ‘”intimate” brands continued to outperform the S&P and Fortune 500 indices in revenue and profit over the past 10 years, according to MBLM’s Brand Intimacy 2017 Report, the largest... Read more
B-Eng introduces SSD Health Check for Mac OS
Fehraltorf, Switzerland based independant Swiss company- B-Eng has announced the release and immediate availability of SSD Health Check 1.0, the company’s new hard drive utility for Mac OS X. As the... Read more
Apple’s Education discount saves up to $300 o...
Purchase a new Mac or iPad using Apple’s Education Store and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free: -... Read more
4-core 3.7GHz Mac Pro on sale for $2290, save...
Guitar Center has the 3.7GHz 4-core Mac Pro (MD253LL/A) on sale for $2289.97 including free shipping or free local store pickup (if available). Their price is a $710 savings over standard MSRP for... Read more
128GB Apple iPad Air 2, refurbished, availabl...
Apple has Certified Refurbished 128GB iPad Air 2s WiFis available for $419 including free shipping. That’s an $80 savings over standard MSRP for this model. A standard Apple one-year warranty is... Read more
13-inch 2.7GHz Retina MacBook Pro on sale for...
B&H Photo has the 2015 13″ 2.7GHz/128GB Retina Apple MacBook Pro on sale for $100 off MSRP. Shipping is free, and B&H charges NY tax only: - 13″ 2.7GHz/128GB Retina MacBook Pro (MF839LL/A): $... Read more
Laptop Market – Flight To Quality? – The ‘Boo...
Preliminary quarterly PC shipments data released by Gartner Inc. last week reveal an interesting disparity between sales performance of major name PC vendors as opposed to that of less well-known... Read more

Jobs Board

*Apple* macOS Systems Integration Administra...
…most exceptional support available in the industry. SCI is seeking an Junior Apple macOS systems integration administrator that will be responsible for providing Read more
*Apple* Retail - Multiple Positions- Deer Pa...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Technician - nfrastructure (United S...
Let’s Work Together Apple Technician This position is based in Portland, ME Life at nfrastructure At nfrastructure, we understand that our success results from our Read more
*Apple* Mobile Master - Best Buy (United Sta...
**467692BR** **Job Title:** Apple Mobile Master **Location Number:** 000602-Columbia MO-Store **Job Description:** **What does a Best Buy Apple Mobile Master Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.