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

Logic Pro X 10.1.1 - Music creation and...
Apple Logic Pro X is the most advanced version of Logic ever. Sophisticated new tools for professional songwriting, editing, and mixing are built around a modern interface that's designed to get... Read more
VLC Media Player 2.2.0 - Popular multime...
VLC Media Player is a highly portable multimedia player for various audio and video formats (MPEG-1, MPEG-2, MPEG-4, DivX, MP3, OGG, ...) as well as DVDs, VCDs, and various streaming protocols. It... Read more
Sound Studio 4.7.8 - Robust audio record...
Sound Studio lets you easily record and professionally edit audio on your Mac. Easily rip vinyls and digitize cassette tapes, or record lectures and voice memos. Prepare for live shows with live... Read more
LibreOffice 4.4.1.2 - Free, open-source...
LibreOffice is an office suite (word processor, spreadsheet, presentations, drawing tool) compatible with other major office suites. The Document Foundation is coordinating development and... Read more
Freeway Pro 7.0.3 - Drag-and-drop Web de...
Freeway Pro lets you build websites with speed and precision... without writing a line of code! With its user-oriented drag-and-drop interface, Freeway Pro helps you piece together the website of... Read more
Cloud 3.3.0 - File sharing from your men...
Cloud is simple file sharing for the Mac. Drag a file from your Mac to the CloudApp icon in the menubar and we take care of the rest. A link to the file will automatically be copied to your clipboard... Read more
Cyberduck 4.6.5 - FTP and SFTP browser....
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
Firefox 36.0 - Fast, safe Web browser. (...
Firefox for Mac offers a fast, safe Web browsing experience. Browse quickly, securely, and effortlessly. With its industry-leading features, Firefox is the choice of Web development professionals and... Read more
Thunderbird 31.5.0 - Email client from M...
As of July 2012, Thunderbird has transitioned to a new governance model, with new features being developed by the broader free software and open source community, and security fixes and improvements... Read more
VOX 2.4 - Music player that supports man...
VoxIt just sounds better! The beauty is in its simplicity, yet behind the minimal exterior lies a powerful music player with a ton of features & support for all audio formats you should ever need... Read more

Get The Whole Story – Lone Wolf Complete...
Get The Whole Story – Lone Wolf Complete is Now Available and On Sale Posted by Jessica Fisher on February 27th, 2015 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Who Wore it Best? The Counting Dead vs....
Like it or not, the “clicker” genre, popularized by cute distractions like Candy Box and Cookie Clicker, seems like it’s here to stay. So Who Wore it Best? takes a look at two recent examples: The Counting Dead and AdVenture Capitalist. | Read more »
Card Crawl, the Mini Deck Building Game,...
Card Crawl, the Mini Deck Building Game, is Coming Soon Posted by Jessica Fisher on February 27th, 2015 [ permalink ] Tinytouchtales and Mexer have announced their new game, | Read more »
Witness an all new puzzle mechanic in Bl...
Well, BlastBall MAX is not one of those games and is bucking trends such as timers, elements of randomness, and tacked-on mechanics in favor of pure puzzle gameplay. When you first boot up the game you’ll see a grid made up of squares that are each... | Read more »
This Princess Has a Dragon and She isn’t...
This Princess Has a Dragon and She isn’t Afraid to Useit. | Read more »
Mecha Showdown Review
Mecha Showdown Review By Lee Hamlet on February 27th, 2015 Our Rating: :: IN A SPINUniversal App - Designed for iPhone and iPad Mecha Showdown replaces traditional buttons with a slot machine mechanic in this robot fighting game,... | Read more »
Reliance Games and Dreamworks Unveil Rea...
Reliance Games and Dreamworks Unveil Real Steel Champions Posted by Ellis Spice on February 27th, 2015 [ permalink ] Reliance Games and Dreamworks have announced that a third game in | Read more »
Sum Idea Review
Sum Idea Review By Jennifer Allen on February 27th, 2015 Our Rating: :: TAXING NUMBERSUniversal App - Designed for iPhone and iPad Sum Idea is a fairly charming but taxing puzzle game.   | Read more »
A New Badland Update Brings Daydream Lev...
A New Badland Update Brings Daydream Levels to Co-Op Posted by Ellis Spice on February 27th, 2015 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Slashing Demons Review
Slashing Demons Review By Lee Hamlet on February 27th, 2015 Our Rating: :: IT'S A LONG WAY TO THE TOPUniversal App - Designed for iPhone and iPad Slashing Demons lacks the depth or scope to take it beyond the point of being just... | Read more »

Price Scanner via MacPrices.net

Apple CEO Tim Cook to Deliver 2015 George Was...
Apple CEO Tim Cook will deliver the George Washington University’s Commencement address to GWU grads on May 17, at which time he will also be awarded an honorary doctorate of public service from the... Read more
Apple restocks refurbished Mac minis for up t...
The Apple Store has restocked Apple Certified Refurbished 2014 Mac minis, with models available starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: - 1.4GHz... Read more
Save up to $50 on iPad Air 2s, NY tax only, f...
 B&H Photo has iPad Air 2s on sale for $50 off MSRP including free shipping plus NY sales tax only: - 16GB iPad Air 2 WiFi: $469.99 $30 off - 64GB iPad Air 2 WiFi: $549 $50 off - 128GB iPad Air 2... Read more
16GB iPad Air 2 on sale for $447, save $52
Walmart has the 16GB iPad Air 2 WiFi on sale for $446.99 on their online store for a limited time. Choose free shipping or free local store pickup (if available). Sale price for online orders only,... Read more
iMacs on sale for up to $205 off MSRP
B&H Photo has 21″ and 27″ iMacs on sale for up to $205 off MSRP including free shipping plus NY sales tax only: - 21″ 1.4GHz iMac: $1029 $70 off - 21″ 2.7GHz iMac: $1199 $100 off - 21″ 2.9GHz... Read more
Apple Takes 89 Percent Share of Global Smartp...
According to the latest research from Strategy Analytics, global smartphone operating profit reached US$21 billion in Q4 2014. The Android operating system captured a record-low 11 percent global... Read more
New Travel Health App “My Travel Health” iOS...
Rochester, Minnesota based Travel Health and Wellness LLC has announced that its new iOS app help safeguard the user’s health when traveling abroad — “My Travel Health” is now available on the Apple... Read more
Sale! MacBook Airs for up to $115 off MSRP
B&H Photo has MacBook Airs on sale for up to $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 11″ 128GB MacBook Air: $799 100 off MSRP - 11″ 256GB MacBook Air: $999 $100... Read more
15-inch 2.0GHz Retina MacBook Pro (refurbishe...
The Apple Store has Apple Certified Refurbished previous-generation 15″ 2.0GHz Retina MacBook Pros available for $1489 including free shipping plus Apple’s standard one-year warranty. Their price is... Read more
Wither The iPad mini? End Of The Road Imminen...
AppleDailyReport’s Dennis Sellers predicts that the iPad mini is going to be left to wither on the vine, as it were, and then just allowed to fade away — a casualty of the IPhone 6 Plus and other... Read more

Jobs Board

Sr. Technical Services Consultant, *Apple*...
**Job Summary** Apple Professional Services (APS) has an opening for a senior technical position that contributes to Apple 's efforts for strategic and transactional Read more
Event Director, *Apple* Retail Marketing -...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global engagement strategy and team. Delivering an overarching brand Read more
*Apple* Pay - Site Reliability Engineer - Ap...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
*Apple* Solutions Consultant - Retail Sales...
**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 - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.