COMPUTER AUDIO/FMOD
CGDD 4603
Why fmod?

Sound you might have in a game:
 Background
music
 Sound effects
 Dialog


How do you currently use these in your games?
fmod is very popular
 Powerful
– both 2D and 3D sound, DSP/effects…
 Cross platform (PS3, Wii, PC…)
 Has a designer, sandbox and API
Partial List of Games that use fmod

Allods Online

Guitar Hero III

Audition Online

Guitar Hero: Aerosmith

Battlestations: Pacific

Guitar Hero: World Tour

BioShock

Heavenly Sword

BioShock2

Heroes of Newerth

Brutal Legend

Hellgate: London

Clive Barker's Jericho

Jurassic Park: Operation Genesis

Cortex Command

Just Cause 2

Crysis

League of Legends

Darkfall

Lego Universe

DJ Hero

LittleBigPlanet/LBP2

Batman: Arkham Asylum

Metroid Prime 3

De Blob

Natural Selection 2

Dragon Age: Origins

Need for Speed: Shift

Dogfighter

Nicktoons Unite!

Far Cry


Forza Motorsport 2

Forza Motorsport 3

Guild Wars
Nicktoons: Across the Second
Dimension
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Plants vs Zombies
Pure
Rise of Flight: The First Great Air War
Second Life
Shatter
Shattered Horizon[4]
Silent Hill: Shattered Memories
StarCraft II: Wings of Liberty
Stargate Worlds
Stranglehold
TimeShift
TNA iMPACT!
Tom Clancy's Ghost Recon
Tom Clancy's Rainbow Six Vegas 2
Tomb Raider: Underworld
Torchlight
Tropico 3
vSide
World of Tanks
World of WarCraft
You Don't Know Jack
Zuma
Things You Should Know…


ADC/DAC – Audio to Digital Conversion
Sampling rate
#
of times per second the computer “listens”
 44.1 KHz is CD
 22 KHz is good

Bits per sample
 Computers
have to approximate
 4 bits = 16 levels of approximation
 8 bits = 256 levels of approximation
Original Sound
Low Sampling Rate
TIME
Low Sampling Rate
What the computer hears
TIME
High Sampling Rate
TIME
High Sampling Rate
TIME
2 bits per sample
4 Approximations
TIME
StairStep Effect
TIME
3 bits per sample
8 Approximations
TIME
Less StairStep
TIME
Capturing Sounds

Usually done with:





Computer has sound card



a microphone (such as voice)
Line in
CD
Hollywood Edge®
Input types (RCA, MIDI, mini, ¼”, XLR)
Card has quality (plays 16-bit sound)
Need some kind of software


SoundForge/Audacity
Windows SoundRecorder (gag)
3D Sound



Sounds have position and velocity
There is a listener component
Relationship between the two
 Attenuation
(with distance)
 Occlusion (low-pass filter)
 Doppler (relative velocities)

Lots of “psycho-acoustic” options
Back to fmod

There are three primary components:
 The
Sound Designer
 The Sandbox
 The API


We’ll use all three
Start with Sound Designer
Setting up a Project

Take the advice of the video tutorials
 Have
a separate folder
 Copy sounds into a “sounds” directory
 Keeps
the safe
 Can have sub-directories
 Create
an “output” directory
Designer Interface
Can delete this if you want, but need to have at
least one group
Events


Used to define sound properties for an event
Can be comprised of
 One
sound
 Several sounds randomly chosen
 Monophonic vs Polyphonic
 Can randomize pitch and attenuation

Events can be
 Simple
 Multi-track
A Simple Event
Granular Sounds



These sounds aren’t
looping
Allows for a sounds to
occur between time
ranges
Allows for polyphony
Event Options




Can vary attenuation
(dropoff with distance)
Can vary pitch
Creates a sound
considerably smaller
than a “soundtrack”
Plays forever and is
always random!
Sound Definitions

Required for multi-track events
Multi-track Events

Comprised of sound defs in layers
Multi-track Events

Careful when adding sounds
 Choose
sound def
 Ambient noise is looping
 Other sounds are granular,
so choose “Oneshot”


Have parameters
Not based on time!
Multi-track Events

Can cross-fade and set fade out time
Effects
Parameter Properties

Can define range and velocity (to simulate time)
Engine Designer

fmod can specifically work with engine sounds
 Need


for Speed 2
Based on the “load” of the engine
Right-click on a
sound instance->properties
 Auto-pitch

Window->fmod Engine Designer
The Build Process

Know which platform you’re targeting
 Changes

are applied only to that platform
Project->Clean, Project->Build
Interactive Music

Comprised of several short segments of music
 Intro
music
 Darkening or discovery
 Fighting/intense fighting
 Release

Before you begin, you must know
 Tempo
of music (beats per minute – bpm)
 Beats per measure (time signature)
Cues
Themes and Auditioning
Transitioning via Parameters
Other Things


Supports deployment of multiple languages
Can deploy different builds based on
 Platform
 Language
A Look at the API


Basic API
Designer API
 Built
on basic API
 Can read .fev files

Written for C/C++
 #include
<fmod.h> // C
 #include <fmod.hpp> // C++

Read the documentation fmodex.chm
API Parts


A System is the fmod engine
A Sound is the raw resource
 2D
uses FMOD_2D
 3D uses FMOD_3D
result = system->createSound(“music.wav", FMOD_2D, 0, &sound);
API Parts

A Channel is an instance of a Sound
 Each
time you play a sound, you get a new channel
 Channels can start out paused
 You can set the
 Volume
(0.0f – 1.0f)
 Pan (-1.0f – 1.0f)
 Frequency (in Hz as a float)
 Always
use FMOD_CHANNEL_FREE to pick for you
#include <iostream>
#include <fmod.hpp>
#include <fmod_errors.h>
using namespace std;
using namespace FMOD;
void main () {
FMOD_RESULT result;
System* system;
// Create the fmod system. We only need one of these
result = System_Create(&system);
// Specify a max number of simultaneous channels
result = system->init(100, FMOD_INIT_NORMAL, 0);
Sound* sound;
// Decompress the entire mp3 into 16-bit PCM in memory
result = system->createSound("winning.mp3", FMOD_DEFAULT, 0, &sound);
if (result != FMOD_OK) {
cout << "Couldn't open it! " <<
}
FMOD_ErrorString(result) << endl;
Channel* channel;
// Used for setting volume, pan, pausing...
// You have the option of passing that channel as the last parameter
result = system->playSound(FMOD_CHANNEL_FREE, sound, false, &channel);
channel->setFrequency (44100.0f);
if (result != FMOD_OK) {
cout << "Couldn't play it! " << FMOD_ErrorString(result) << endl;
}
while (true) {
cout << "1"; system->update(); // Now required in fmod
}
}
Virtual Voices

Supports “virtual voices” when hardware is limited
 Set

System::getCPUUsage()
 Try


from System::init()
to keep < 1000
May need to set the
priority of a channel
if it’s important
channel->isVirtual()
3D Sound in fmod

Sound attenuation
Logarithmic
 Set the mindistance of a sound channel to start
attenuation

Bee = 0.1f
 Jet = 50.0f



Leave max distance alone (default is 10,000)
Set 3D settings with System::set3DSettings()
Doppler
 Distance factor (in cm, m, feet)
 Rolloff scale (attenuation models)

3D Sound

fmod uses a left-handed coordinate system
result=system->init(100,
(FMOD_MODE)(FMOD_INIT_3D_RIGHTHANDED|FMOD_3D), 0);

With velocity, you must pass it as meters per second
velx = (posx-lastposx) * 1000 / timedelta;
vel = 0.1 * 1000 / 16.67 = 6 meters per second
vel = 0.2 * 1000 / 33.33 = 6 meters per second
void main () {
FMOD_RESULT result;
FMOD_VECTOR soundPos, soundVel;
FMOD_VECTOR listenerPos, listenerVel, listenerForward, listenerUp;
System* system;
result = System_Create(&system);
result = system->init(100, (FMOD_MODE)(FMOD_3D), 0);
int numHC = 0;
result = system->getHardwareChannels(&numHC);
cout << "Hardware channels: " << numHC << endl;
Sound* sound;
result = system->createSound(“train.mp3", FMOD_3D, 0, &sound);
if (result != FMOD_OK) {
cout << "Couldn't open it! " << FMOD_ErrorString(result) << endl;
}
Channel* channel;
result = system->playSound(FMOD_CHANNEL_FREE, sound, false, &channel);
channel->setFrequency(44100.0f);
if (result != FMOD_OK) {
cout << "Couldn't play it! " << FMOD_ErrorString(result) << endl;
}
float dsp, stream, geometry, update, total;
soundPos.y = soundVel.x = soundVel.y = 0.0f;
soundPos.z = -100.0f; soundPos.x = 5.0f;
soundVel.z = 6.0f;
channel->set3DMinMaxDistance(10, 10000);
listenerPos.x = listenerPos.y = listenerPos.z = 0.0f;
listenerVel.x = listenerVel.y = listenerVel.z = 0.0f;
listenerForward.x = listenerForward.y = listenerUp.x = listenerUp.z = 0.0f;
listenerForward.z = listenerUp.y = 1.0f;
system->set3DListenerAttributes(0, &listenerPos, &listenerVel, &listenerForward, &listenerUp);
while (true) {
}
}
system->update();
system->getCPUUsage(&dsp, &stream, &geometry, &update, &total);
cout << total << endl;
soundPos.z+=0.01f;
channel->set3DAttributes(&soundPos, &soundVel);
Interfacing with Sound Designer

You should have received
 .fev
file (Designer file – event data)
 .fsb file (raw audio data)
 .txt file (describes the events and parameters)

May want to start by creating a helper function
void checkErrors(FMOD_RESULT result) {
if (result != FMOD_OK) {
cout << "fmod error: " << FMOD_ErrorString(result) << endl;
exit(1);
}
}
Imagine That This is our Project
#include <iostream>
#include <fmod.hpp>
#include <fmod_event.hpp>
#include <fmod_errors.h>
using namespace std;
using namespace FMOD;
void main () {
EventSystem* eventSystem = NULL;
EventGroup* eventGroup = NULL;
Event* myEvent = NULL;
EventParameter* eventPar;
FMOD_RESULT result = EventSystem_Create(&eventSystem);
checkErrors(result);
result = eventSystem->init(64, FMOD_INIT_NORMAL, 0, FMOD_EVENT_INIT_NORMAL);
eventSystem->setMediaPath("..//");
result = eventSystem->load("fmodTest.fev", 0, 0);
result = eventSystem->getGroup("fmodTest/beeps", false, &eventGroup);
result = eventGroup->getEvent("PossessedComputer", FMOD_EVENT_DEFAULT, &myEvent);
result = myEvent->getParameter("proximityToComputer", &eventPar);
myEvent->start();
float dir = 0.0001f;
float currentParVal = -1.0f;
eventPar->setValue(0.1f);
while (true){
cout << currentParVal << endl;
eventPar->getValue(&currentParVal);
currentParVal+=dir;
eventPar->setValue(currentParVal);
if ((currentParVal >= 1.0)||(currentParVal <= 0.0)) {
dir = -dir;
}
}
}
Interactive Music
void main () {
EventSystem* eventSystem = NULL;
MusicSystem* musicSystem = NULL;
MusicPrompt* introPrompt, *fightPrompt, *fight2Prompt, *releasePrompt;
FMOD_MUSIC_ITERATOR cueIter;
FMOD_MUSIC_ITERATOR paramIter;
FMOD_MUSIC_ID intensityParID = -1.0f;
FMOD_RESULT result = EventSystem_Create(&eventSystem);
result = eventSystem->init(64, FMOD_INIT_NORMAL, 0,
FMOD_EVENT_INIT_NORMAL);
result = eventSystem->load("acid_test.fev", 0, 0);
result = eventSystem->getMusicSystem(&musicSystem);
musicSystem->setVolume(1.0f);
result = musicSystem->getCues(&cueIter);
cout << "Iter ID: " << cueIter.value->id << endl;
result = musicSystem->prepareCue(cueIter.value->id, &fightPrompt);
result = musicSystem->getNextCue(&cueIter);
cout << "Iter ID: " << cueIter.value->id << endl;
result = musicSystem->prepareCue(cueIter.value->id, &fight2Prompt);
result = musicSystem->getNextCue(&cueIter);
result = musicSystem->prepareCue(cueIter.value->id, &introPrompt);
result = musicSystem->getNextCue(&cueIter);
result = musicSystem->prepareCue(cueIter.value->id, &releasePrompt);
musicSystem->getParameters(&paramIter);
intensityParID = paramIter.value->id;
cout << "paramIter.value->name is " << paramIter.value->name << endl;
musicSystem->setParameterValue(intensityParID, 7.5f);
result = introPrompt->begin();
}
while (true){
eventSystem->update();
}
Other Things You Should Look Into…



The 3D Reverb API
Asynchronously loading data (by default)
Memory management for non-PC platforms
 FMOD::Memory_Initialize()
 Using

compressed samples
Built-in DSP
// fix size of fmod
Configuration Notes

You’ll be working with
 Header
files
 C/C++
 Lib
-> General->Additional Include Directories
files
 Linker->General->Additional
Library Directories
 Linker->General->Additional Dependencies
 DLLs

(which you should put into Windows/System32)
There’s also a FMOD.NET site…
Configuration Notes

You have the option of 64-bit and 32-bit libraries
 You
might have to create a new platform