TweetFollow Us on Twitter

Sound 101
Volume Number:9
Issue Number:3
Column Tag:C Workshop

Related Info: Sound Manager

Sound 101

Evolution of the Mac voice

By Iggi Monahelis, Pleasanton, California

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

About the author

Iggi Monahelis is a programmer who bought his first Mac as soon as he could back in 1984. He is the principal designer and co-author of “Read My Lips”, the sound annotation utility for the Macintosh.

Introduction

This is an introductory article, hence the name Sound 101, dealing with basic recording and playback of sounds on the Macintosh. It explains the required steps to be taken in order to digitize sounds using a microphone, in two different sound formats, and play them back. It is a good stepping stone for someone who has little or no knowledge of how to do these things in a program on the Macintosh. As a matter of fact, one can probably copy the routines given in the article, and use them in their own program without a lot of modifications.

Ancient History

The Macintosh has had the capability of producing sounds since day one. The famous introduction of the Macintosh back in 1984 used sound, in the form of digitized speech, to allow the Mac to introduce itself. Inside Macintosh back then had a chapter on the Sound Driver with just a few routines, literally StartSound, StopSound and SoundDone, that allowed the programmer to control the Sound Driver. The Sound Driver produced sound using three different sound synthesizers:

1) the four-tone synthesizer, used to make simple harmonic tones, with up to four “voices” producing sound simultaneously. Hence the name four-tone.

2) the square-wave synthesizer, used to produce sounds such as beeps.

3) the free-form synthesizer, used to produce complex sounds, music and speech.

You had to “describe” the sound to the Driver as a waveform, basically fill a buffer with a bunch of numbers, and tell the Sound Driver to start producing noise based on these numbers. Very primitive.

Middle Ages

With the introduction of the Macintosh II class of machines, the Sound Driver had graduated to the Sound Manager. It was indeed a graduation because several innovations had taken place:

1) The hardware now included a new sound chip which freed the machine’s processor from doing all the work.

2) The introduction of sound resources. Sound resources can “contain” any sound you can imagine, from a simple beep sound to digital recordings of CD’s. And because they are resources, in the Macintosh sense of the word, you can work with them using standard Resource Manager calls. To play a sound resource all you have to do is load it and pass the handle to the resource to the SndPlay routine.

3) The Sound Manager now has seven routines to allow you to work with sound.

To produce sound, commands are sent to a synthesizer, as was the case with the Sound Driver. The Sound Manager uses a queue to send these commands to a synthesizer, these queues are called channels. To make complex sounds, many sounds may need to be produced simultaneously. For this reason several synthesizers can have multiple channels.

The new Sound Manager uses three synthesizers to produce sound:

1) the wave-table synth, lets you supply a wave table that describes the sound. This lets you produce more complex sounds, also it lets you play multiple sounds simultaneously by opening several channels. It corresponds to the old four-tone synth with four channels open.

2) the note synth, used to produce simple sounds, such as a note. The note synth can produce only one note at a time. It compares to the old square-wave synth from the Sound Driver.

3) the sampled sound synth, used to play digitally recorded sounds. In this case instead of passing the note or a wave table describing the sound you want played, you pass a buffer that contains samples of the sound to be played. This synth compares to the old free-form synth from the Sound Driver.

Despite the innovations that came with the Mac II and the graduation of the Sound Driver to a Manager, it was still difficult to digitize sounds using System software. It was easy once you had a sound resource to play it and several programs, mostly shareware, were created to play sound resources. Farallon came out with the MacRecorder® sound digitizer which allowed you to digitize sounds using the software that came with it, but still you could not do that in your own program without writing a lot of code yourself.

Today

With the introduction of the Macintosh IIsi and Macintosh LC, Apple for the first time included a built-in microphone with the Macintosh. System software versions 6.0.7 and later have a new and improved version of the Sound Manager. The Sound Manager chapter goes from 32 pages to 114 pages. This latest version introduces a whole slew of new features, some of which are:

1) There are now routines to record sounds using the built-in microphones, or any third party microphone with the appropriate driver for Macs that do not come with a microphone.

2) One can record either sound resources (‘snd ‘), or record directly to a file on disk in a format known as: Audio Interchange File Format (AIFF).

3) There are routines that allow for compressing and decompressing of sound data.

4) There are now routines that allow for the playing of sounds directly from disk. So one does not have to load all of the sound in memory in order to play it.

5) Customization galore. Besides the high-level routines for recording and playback there are low-level routines so that one could customize the way recording and playback is done.

Writing the program

It is always easier to start with a basic program, understand it, and then expand on it. The Sound 101 program is just such a program for learning the basics about recording and playing sounds. The program can record and play 'snd ' and AIFF sound files. It also allows for the selection of sound quality.

Here goes the code with explanations...

Sound101_main.c
/***********************************************************
© 1992 Praxitel, Inc. and Iggi Monahelis

This is the “main” for the Sound 101 project.  It has the minimum stuff 
to get a mac
program going.  Basically, it does all the required mac initializations, 
sets up the menu
bar, and then gets and processes events.

***********************************************************/
#include “Sound101.h”


extern int  gDestroyChannel;
extern SndChannelPtr gSndChan;
extern short     gFRefNum;
extern long gQuality;

/***********************************************************

main

This is the main routine for the Sound 101 application, it does all the 
Mac initializations.
Then calls the EventLoop procedure to get and process events.

***********************************************************/
void main(void)
{
 InitGraf((Ptr) &thePort );
 InitFonts();
 InitWindows();
 InitMenus();
 TEInit();
 InitDialogs(0L);
 InitCursor();
 
 MaxApplZone();
 SetUpMenus();

 EventLoop();    /* Do event processing until user quits */

}

/***********************************************************

SetUpMenus

Set up the menu bar for the Sound 101 application
 
***********************************************************/
void SetUpMenus(void)
{
 MenuHandle myMenu;
 
 myMenu = GetMenu(mApple);
 
 AddResMenu( myMenu, ‘DRVR’ );
 InsertMenu( myMenu, 0 );
 InsertMenu(GetMenu(mFile), 0) ;
 DrawMenuBar();
}

/***********************************************************

EventLoop

Event handling for the Sound 101 application.
Get events forever, and handle them by calling DoEvent.
 
***********************************************************/
void EventLoop(void)
{
 BooleangotEvent;
 EventRecordevent;

 do {
 gotEvent = WaitNextEvent(everyEvent, &event, 50, 0);
 if ( gotEvent ) {
 DoEvent(&event);
 }
 /* if we are done with the sound, dispose the sound 
    channel and close the sound file. */     
 if ( gDestroyChannel ) { 
 OSErr  myErr;
 
 InitCursor();
 if (gSndChan)
 myErr = SndDisposeChannel( gSndChan, TRUE);
 if (gFRefNum)
 myErr = FSClose(gFRefNum);
 /* make sure we do it only once! */
 gDestroyChannel = FALSE;
 gSndChan = 0;
 gFRefNum = 0;
 } 
 } while ( true ); /* loop forever */
} /*EventLoop*/

/***********************************************************

DoEvent

Determine the event type and dispatch accordingly
 
***********************************************************/
void DoEvent(EventRecord *event)
{
 short  part, err;
 WindowPtrwindow;
 char   key;

 switch ( event->what ) {
 case nullEvent:
 break;
 case mouseDown:
 part = FindWindow(event->where, &window);
 switch ( part ) {
 case inMenuBar:
 /* process a mouse menu command */
 DoMenuCommand(MenuSelect(event->where));
 break;
 case inSysWindow:
 /* let the system handle the mouseDown */
 SystemClick(event, window);
 break;
 case inContent:
 break;
 case inDrag:                
 break;
 case inGoAway:
 break;
 case inGrow:
 break;
 case inZoomIn:
 case inZoomOut:
 break;
 }
 break;
 case keyDown:
 case autoKey:
 /* check for menukey equivalents */
 key = event->message & charCodeMask;
 if ( event->modifiers & cmdKey ) {
 /* Command key down */
 /* if command-period was pressed, set our global
    to clean up the sound channel and close the
    open sound file. */
 if ( key == ‘.’ )
 /* command period was pressed */
 gDestroyChannel = TRUE;
 }
 break;
 case activateEvt:
 break;
 case updateEvt:
 break;
 }
} /*DoEvent*/

/***********************************************************

DoMenuCommand

Handles menu selections for the Sound 101 application
   
***********************************************************/
void DoMenuCommand(long menuResult)
{
 short  menuID, menuItem;
 short  itemHit, daRefNum;
 Str255 daName;

 menuID = HiWord(menuResult);
 menuItem = LoWord(menuResult);
 switch ( menuID ) {
 case mApple:
 switch ( menuItem ) {
 case iAbout: {  /* bring up the About box */
 OSErr  err;
 GrafPtroldPort;
 Rect   tempRect;
 DialogPtraboutDlg;
 
 GetPort(&oldPort);
 
 aboutDlg = GetNewDialog(128, nil, (WindowPtr) -1);
 if ( aboutDlg ) {
 /* Open a dialog box */
 ShowWindow(aboutDlg);    
 SelectWindow(aboutDlg);  /* Lets see it */
 SetPort(aboutDlg);
 while (TRUE) {
 ModalDialog(NULL, &itemHit);
 if ( itemHit == 1 )
 break;
 }
 DisposDialog(aboutDlg);
 SetPort(oldPort);
 }
 }
 break;

 default:
 /* all non-About items in this menu are DAs */
 GetItem(GetMHandle(mApple), menuItem, daName);
 daRefNum = OpenDeskAcc(daName);
 break;
 }
 break;
 
 case mFile:
 switch ( menuItem ) {
 case iPlaySound:
 PlayASound();
 break;
 case iRecordsndSound:
 Record_snd_resource(gQuality);
 break;
 case iRecordAIFFSound:
 Record_AIFF_sound(gQuality);
 break;
 case iQuality:
 GetQuality();
 break;
 case iQuit:
 Terminate();
 break;
 }
 break;
 } 
 
 /* unhighlight what MenuSelect (or MenuKey) hilited */
 HiliteMenu(0);  
}

/***********************************************************

Terminate

Quit the app
   
***********************************************************/
void Terminate(void)
{
 /* exit if no cancellation */
 ExitToShell();  
} /*Terminate*/
 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Fantastical 2.3.2 - Create calendar even...
Fantastical 2 is the Mac calendar you'll actually enjoy using. Creating an event with Fantastical is quick, easy, and fun: Open Fantastical with a single click or keystroke Type in your event... Read more
PCalc 4.4.4 - Full-featured scientific c...
PCalc is a full-featured, scriptable scientific calculator with support for hexadecimal, octal, and binary calculations, as well as an RPN mode, programmable functions, and an extensive set of unit... Read more
Alfred 3.2.1 - Quick launcher for apps a...
Alfred is an award-winning productivity application for OS X. Alfred saves you time when you search for files online or on your Mac. Be more productive with hotkeys, keywords, and file actions at... Read more
OmniPlan 3.6 - Robust project management...
With OmniPlan, you can create logical, manageable project plans with Gantt charts, schedules, summaries, milestones, and critical paths. Break down the tasks needed to make your project a success,... Read more
Backblaze 4.2.0.990 - Online backup serv...
Backblaze is an online backup service designed from the ground-up for the Mac. With unlimited storage available for $5 per month, as well as a free 15-day trial, peace of mind is within reach with... Read more
AppDelete 4.3.1 - $7.99
AppDelete is an uninstaller that will remove not only applications but also widgets, preference panes, plugins, and screensavers along with their associated files. Without AppDelete these associated... Read more
Apple GarageBand 10.1.4 - Complete recor...
The new GarageBand is a whole music creation studio right inside your Mac -- complete with keyboard, synths, orchestral and percussion instruments, presets for guitar and voice, an entirely... Read more
Adobe Lightroom 6.8 - Import, develop, a...
Adobe Lightroom is available as part of Adobe Creative Cloud for as little as $9.99/month bundled with Photoshop CC as part of the photography package. Lightroom 6 is also available for purchase as a... Read more
iMazing 2.1.3 - Complete iOS device mana...
iMazing (was DiskAid) is the ultimate iOS device manager with capabilities far beyond what iTunes offers. With iMazing and your iOS device (iPhone, iPad, or iPod), you can: Copy music to and from... Read more
Little Snitch 3.7.1 - Alerts you about o...
Little Snitch gives you control over your private outgoing data. Track background activity As soon as your computer connects to the Internet, applications often have permission to send any... Read more

Latest Forum Discussions

See All

Galaxy on Fire 3 and four other fantasti...
Galaxy on Fire 3 - Manticore brings the series back for another round of daring space battles. It's familiar territory for folks who are familiar with the franchise. If you've beaten the game and are looking to broaden your horizons, might we... | Read more »
The best apps for your holiday gift exch...
What's that, you say? You still haven't started your holiday shopping? Don't beat yourself up over it -- a lot of people have been putting it off, too. It's become easier and easier to procrastinate gift shopping thanks to a number of apps that... | Read more »
Toca Hair Salon 3 (Education)
Toca Hair Salon 3 1.0 Device: iOS Universal Category: Education Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Winter comes to Darkwood as Seekers Note...
MyTona, based in the chilly Siberian city of Yakutsk, has brought a little festive fun to its hidden object game Seekers Notes: Hidden Mystery. The Christmas update introduces some new inhabitants to players, and with them a chance to win plenty of... | Read more »
Bully: Anniversary Edition (Games)
Bully: Anniversary Edition 1.03.1 Device: iOS Universal Category: Games Price: $6.99, Version: 1.03.1 (iTunes) Description: *** PLEASE NOTE: This game is officially supported on the following devices: iPhone 5 and newer, iPod Touch... | Read more »
PINE GROVE (Games)
PINE GROVE 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: A pine grove where there are no footsteps of people due to continuous missing cases. The case is still unsolved and nothing has... | Read more »
Niantic teases new Pokémon announcement...
After rumors started swirling yesterday, it turns out there is an official Pokémon GO update on its way. We’ll find out what’s in store for us and our growing Pokémon collections tomorrow during the Starbucks event, but Niantic will be revealing... | Read more »
3 reasons why Nicki Minaj: The Empire is...
Nicki Minaj is as business-savvy as she is musically talented and she’s proved that by launching her own game. Designed by Glu, purveyors of other fine celebrity games like cult favorite Kim Kardashian: Hollywood, Nicki Minaj: The Empire launched... | Read more »
Clash of Clans is getting its own animat...
Riding on its unending wave of fame and success, Clash of Clans is getting an animated web series based on its Clash-A-Rama animated shorts.As opposed to the current shorts' 60 second run time, the new and improved Clash-A-Rama will be comprised of... | Read more »
Leaks hint at Pokémon GO and Starbucks C...
Leaked images from a hub for Starbucks employees suggests that a big Pokémon GO event with the coffee giant could begin this very week. The images appeared on Reddit and hint at some exciting new things to come for Niantic's smash hit game. | Read more »

Price Scanner via MacPrices.net

12-inch Retina MacBooks, Apple refurbished, n...
Apple has restocked a full line of Certified Refurbished 2016 12″ Retina MacBooks, now available for $200-$260 off MSRP. Refurbished 2015 models are available starting at $929. Apple will include a... Read more
Holiday sale: 12-inch Retina MacBook for $100...
B&H has 12″ Retina MacBooks on sale for $100 off MSRP as part of their Holiday sale. Shipping is free, and B&H charges NY sales tax only: - 12″ 1.1GHz Space Gray Retina MacBook: $1199 $100... Read more
Apple refurbished 13-inch MacBook Airs availa...
Apple has Certified Refurbished 13″ MacBook Airs available starting at $849. An Apple one-year warranty is included with each MacBook, and shipping is free: - 13″ 1.6GHz/8GB/128GB MacBook Air: $849 $... Read more
Apple refurbished iMacs available for up to $...
Apple has Certified Refurbished 2015 21″ & 27″ iMacs available for up to $350 off MSRP. Apple’s one-year warranty is standard, and shipping is free. The following models are available: - 21″ 3.... 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
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
Twenty-Five Years Of Apple Laptops – A person...
Among many other things, the often tumultuous 16th year of the new century marked the 25th anniversary of Apple laptop computers, not counting the optimistically named 16-pound Mac Portable of 1989.... Read more
Landlordy iOS App Adds Support For Appliances...
Riga, Latvia based E-protect SIA is releasing major update (version 1.8) to its Landlordy app for managing rental business financials on the go. Landlordy is iPhone and iPad app designed for self-... Read more
Holiday sale, Apple iMacs for up to $200 off...
B&H Photo has 21″ and 27″ Apple iMacs on sale for up to $200 off MSRP including free shipping plus NY sales tax only: - 27″ 3.3GHz iMac 5K: $2099 $200 off MSRP - 27″ 3.2GHz/1TB Fusion iMac 5K: $... Read more
Holiday sale: Mac minis for $50 to $100 off M...
B&H Photo has Mac minis on sale for up to $100 off MSRP free shipping plus NY sales tax only: - 1.4GHz Mac mini: $449 $50 off MSRP - 2.6GHz Mac mini: $629 $70 off MSRP - 2.8GHz Mac mini: $899 $... Read more

Jobs Board

*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* Retail - Multiple Positions- Trumbul...
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
*Apple* Retail - Multiple Positions- Philade...
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- San Ant...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Products Tester Needed - Apple (Unit...
…we therefore look forward to put out products to quality test for durability. Apple leads the digital music revolution with its iPods and iTunes online store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.