Wwise SDK 2021.1.14

MIDI Integration Example

MIDI events are posted by calling the AK::SoundEngine::PostMIDIOnEvent() function. The following code shows examples of:

setting initial MIDI parameters,
posting MIDI events using the event's name (name given to the event by the Wwise user) or the event's ID as defined in "Wwise_IDs.h" (header file generated by Wwise).

#include "Wwise_IDs.h" // IDs generated by Wwise
 
// After Sound Engine initialization, register a global callback function.
// Be sure to register for callback just before the message queue is processed;
// this will ensure that any newly posted MIDI events are processed during
// the current frame (i.e. immediately after we exit our callback function).

AK::SoundEngine::RegisterGlobalCallback( &MIDICallback, AkGlobalCallbackLocation_PreProcessMessageQueueForRender )
 
// Obtain Sound Engine audio settings. These are required to determine the time
// equivalent of one audio frame.

AkAudioSettings audioSettings;

AK::SoundEngine::GetAudioSettings( audioSettings );
 
(...)
 
// Callback function used to post MIDI events.

void MIDICallback( bool in_bLastCall )
{
    // Post MIDI event(s) if required.
    // Take extra care to ensure this code is thread-safe.
 
    // For this example, assume we need to post the note-on and note-off
    // events for the same note.
    AkMIDIPost aPosts[2];
 
    const AkUInt8 byNote = 60;
    const AkUInt8 byChan = 0; // Range 0-15 mapped to MIDI channel range 1-16.
 
    const AkUInt32 uOnSamples = 0; // Note will start at beginning of current frame.
    const AkUInt32 uOffSamples = uOnOffset + audioSettings.uNumSamplesPerFrame / 2;
    // Note will end mid-frame.
    
    // Note-on
    AkMIDIPost& noteOn = aPosts[0];
    noteOn.byType = AK_MIDI_EVENT_TYPE_NOTE_ON;
    noteOn.byChan = byChan;
    noteOn.NoteOnOff.byNote = byNote;
    noteOn.NoteOnOff.byVelocity = 72; // random velocity
    noteOn.uOffset = uOnSamples;
 
    // Note-off
    AkMIDIPost& noteOff = aPosts[1];
    noteOff.byType = AK_MIDI_EVENT_TYPE_NOTE_OFF;
    noteOff.byChan = byChan;
    noteOff.NoteOnOff.byNote = byNote;
    noteOff.NoteOnOff.byVelocity = 0; // not used for note-off
    noteOff.uOffset = uOffSamples;
 
    AkUniqueID eventID = AK::SoundEngine::GetIDFromString( "MIDIEventName" );
    AK::SoundEngine::PostMIDIOnEvent( eventID, REGISTERED_MIDI_GAME_OBJECT, aPosts, 2 );
}

Refer to Integration Details - Events for more information regarding events. Refer to Integration Details - MIDI for more information regarding MIDI.

AkMIDIEvent::byType

AkUInt8 byType

See AK_MIDI_EVENT_TYPE_* pre-processor definitions.

Definition: AkMidiTypes.h:180

AK_MIDI_EVENT_TYPE_NOTE_ON

#define AK_MIDI_EVENT_TYPE_NOTE_ON

Definition: AkMidiTypes.h:57

AkMIDIEvent::tNoteOnOff::byNote

AkMidiNoteNo byNote

Definition: AkMidiTypes.h:190

AkMIDIEvent::byChan

AkMidiChannelNo byChan

Definition: AkMidiTypes.h:181

AK::SoundEngine::RegisterGlobalCallback

AKSOUNDENGINE_API AKRESULT RegisterGlobalCallback(AkGlobalCallbackFunc in_pCallback, AkUInt32 in_eLocation=AkGlobalCallbackLocation_BeginRender, void *in_pCookie=NULL, AkPluginType in_eType=AkPluginTypeNone, AkUInt32 in_ulCompanyID=0, AkUInt32 in_ulPluginID=0)

AkUInt8

uint8_t AkUInt8

Unsigned 8-bit integer.

Definition: AkTypes.h:57

AkMIDIEvent::NoteOnOff

tNoteOnOff NoteOnOff

Definition: AkMidiTypes.h:226

AkMIDIEvent::tNoteOnOff::byVelocity

AkUInt8 byVelocity

Definition: AkMidiTypes.h:191

AkUniqueID

AkUInt32 AkUniqueID

Unique 32-bit ID.

Definition: AkTypes.h:62

AkAudioSettings

Configured audio settings.

Definition: AkTypes.h:213

AK::SoundEngine::PostMIDIOnEvent

AKSOUNDENGINE_API AkPlayingID PostMIDIOnEvent(AkUniqueID in_eventID, AkGameObjectID in_gameObjectID, AkMIDIPost *in_pPosts, AkUInt16 in_uNumPosts, bool in_bAbsoluteOffsets=false, AkUInt32 in_uFlags=0, AkCallbackFunc in_pfnCallback=NULL, void *in_pCookie=NULL, AkPlayingID in_playingID=AK_INVALID_PLAYING_ID)

AK::SoundEngine::GetAudioSettings

AKSOUNDENGINE_API AKRESULT GetAudioSettings(AkAudioSettings &out_audioSettings)

AkGlobalCallbackLocation_PreProcessMessageQueueForRender

@ AkGlobalCallbackLocation_PreProcessMessageQueueForRender

Start of frame rendering, before having processed game messages.

Definition: AkCallback.h:341

AkAudioSettings::uNumSamplesPerFrame

AkUInt32 uNumSamplesPerFrame

Number of samples per audio frame (256, 512, 1024 or 2048).

Definition: AkTypes.h:214

AK::SoundEngine::GetIDFromString

AKSOUNDENGINE_API AkUInt32 GetIDFromString(const char *in_pszString)