Implementing a simple SuperpoweredAdvancedAudioPlayer in swift - ios

Question

I am trying to implement a simple SuperpoweredAdvancedAudioPlayer in swift. I successfully modified the SuperpoweredCrossExample project so that playerA plays the song on starting the application.
ViewController.mm now looks like this:
#import "ViewController.h"
#import "SuperpoweredAdvancedAudioPlayer.h"
#import "SuperpoweredFilter.h"
#import "SuperpoweredRoll.h"
#import "SuperpoweredFlanger.h"
#import "SuperpoweredIOSAudioIO.h"
#import "SuperpoweredSimple.h"
#import <stdlib.h>
#define HEADROOM_DECIBEL 3.0f
static const float headroom = powf(10.0f, -HEADROOM_DECIBEL * 0.025);
/*
This is a .mm file, meaning it's Objective-C++.
You can perfectly mix it with Objective-C or Swift, until you keep the member variables and C++ related includes here.
Yes, the header file (.h) isn't the only place for member variables.
*/
#implementation ViewController {
SuperpoweredAdvancedAudioPlayer *playerA;
SuperpoweredIOSAudioIO *output;
float *stereoBuffer, volA;
unsigned int lastSamplerate;
}
void playerEventCallbackA(void *clientData, SuperpoweredAdvancedAudioPlayerEvent event, void *value) {
if (event == SuperpoweredAdvancedAudioPlayerEvent_LoadSuccess) {
ViewController *self = (__bridge ViewController *)clientData;
self->playerA->setBpm(126.0f);
self->playerA->setFirstBeatMs(353);
self->playerA->setPosition(self->playerA->firstBeatMs, false, false);
};
}
// This is where the Superpowered magic happens.
static bool audioProcessing(void *clientdata, float **buffers, unsigned int inputChannels, unsigned int outputChannels, unsigned int numberOfSamples, unsigned int samplerate, uint64_t hostTime) {
__unsafe_unretained ViewController *self = (__bridge ViewController *)clientdata;
if (samplerate != self->lastSamplerate) { // Has samplerate changed?
self->lastSamplerate = samplerate;
self->playerA->setSamplerate(samplerate);
};
bool silence = !self->playerA->process(self->stereoBuffer, false, numberOfSamples, self->volA);
if (!silence) SuperpoweredDeInterleave(self->stereoBuffer, buffers[0], buffers[1], numberOfSamples); // The stereoBuffer is ready now, let's put the finished audio into the requested buffers.
return !silence;
}
- (void)viewDidLoad {
[super viewDidLoad];
[self f];
}
- (void) f {
volA = 1.0f * headroom;
if (posix_memalign((void **)&stereoBuffer, 16, 4096 + 128) != 0) abort(); // Allocating memory, aligned to 16.
playerA = new SuperpoweredAdvancedAudioPlayer((__bridge void *)self, playerEventCallbackA, 44100, 0);
playerA->open([[[NSBundle mainBundle] pathForResource:#"lycka" ofType:#"mp3"] fileSystemRepresentation]);
output = [[SuperpoweredIOSAudioIO alloc] initWithDelegate:(id<SuperpoweredIOSAudioIODelegate>)self preferredBufferSize:12 preferredMinimumSamplerate:44100 audioSessionCategory:AVAudioSessionCategoryPlayback channels:2 audioProcessingCallback:audioProcessing clientdata:(__bridge void *)self];
[output start];
playerA->play(false);
}
- (void)dealloc {
delete playerA;
free(stereoBuffer);
#if !__has_feature(objc_arc)
[output release];
[super dealloc];
#endif
}
- (void)interruptionStarted {}
- (void)recordPermissionRefused {}
- (void)mapChannels:(multiOutputChannelMap *)outputMap inputMap:(multiInputChannelMap *)inputMap externalAudioDeviceName:(NSString *)externalAudioDeviceName outputsAndInputs:(NSString *)outputsAndInputs {}
- (void)interruptionEnded { // If a player plays Apple Lossless audio files, then we need this. Otherwise unnecessary.
playerA->onMediaserverInterrupt();
}
#end
I am trying to use the same code in swift following the same method used in SuperpoweredFrequencies project to import c++ files in swift.
Superpowered.h:
#import <UIKit/UIKit.h>
#interface Superpowered: NSObject
-(void) f;
#end
Superpowered.mm:
#import "Superpowered.h"
#import "Superpowered/Headers/SuperpoweredAdvancedAudioPlayer.h"
#import "Superpowered/Headers/SuperpoweredFilter.h"
#import "Superpowered/Headers/SuperpoweredRoll.h"
#import "Superpowered/Headers/SuperpoweredFlanger.h"
#import "Superpowered/SuperpoweredIOSAudioIO.h"
#import "Superpowered/Headers/SuperpoweredSimple.h"
#import <stdlib.h>
#define HEADROOM_DECIBEL 3.0f
static const float headroom = powf(10.0f, -HEADROOM_DECIBEL * 0.025);
/*
This is a .mm file, meaning it's Objective-C++.
You can perfectly mix it with Objective-C or Swift, until you keep the member variables and C++ related includes here.
Yes, the header file (.h) isn't the only place for member variables.
*/
#implementation Superpowered {
SuperpoweredAdvancedAudioPlayer *playerA;
SuperpoweredIOSAudioIO *output;
float *stereoBuffer, volA;
unsigned int lastSamplerate;
}
void playerEventCallbackA(void *clientData, SuperpoweredAdvancedAudioPlayerEvent event, void *value) {
if (event == SuperpoweredAdvancedAudioPlayerEvent_LoadSuccess) {
Superpowered *self = (__bridge Superpowered *)clientData;
self->playerA->setBpm(126.0f);
self->playerA->setFirstBeatMs(353);
self->playerA->setPosition(self->playerA->firstBeatMs, false, false);
};
}
// This is where the Superpowered magic happens.
static bool audioProcessing(void *clientdata, float **buffers, unsigned int inputChannels, unsigned int outputChannels, unsigned int numberOfSamples, unsigned int samplerate, uint64_t hostTime) {
__unsafe_unretained Superpowered *self = (__bridge Superpowered *)clientdata;
if (samplerate != self->lastSamplerate) { // Has samplerate changed?
self->lastSamplerate = samplerate;
self->playerA->setSamplerate(samplerate);
};
bool silence = !self->playerA->process(self->stereoBuffer, false, numberOfSamples, self->volA);
if (!silence) SuperpoweredDeInterleave(self->stereoBuffer, buffers[0], buffers[1], numberOfSamples); // The stereoBuffer is ready now, let's put the finished audio into the requested buffers.
return !silence;
}
- (void)f {
volA = 1.0f * headroom;
if (posix_memalign((void **)&stereoBuffer, 16, 4096 + 128) != 0) abort(); // Allocating memory, aligned to 16.
playerA = new SuperpoweredAdvancedAudioPlayer((__bridge void *)self, playerEventCallbackA, 44100, 0);
playerA->open([[[NSBundle mainBundle] pathForResource:#"lycka" ofType:#"mp3"] fileSystemRepresentation]);
output = [[SuperpoweredIOSAudioIO alloc] initWithDelegate:(id<SuperpoweredIOSAudioIODelegate>)self preferredBufferSize:12 preferredMinimumSamplerate:44100 audioSessionCategory:AVAudioSessionCategoryPlayback channels:2 audioProcessingCallback:audioProcessing clientdata:(__bridge void *)self];
[output start];
playerA->play(false);
}
- (void)dealloc {
delete playerA;
free(stereoBuffer);
#if !__has_feature(objc_arc)
[output release];
[super dealloc];
#endif
}
- (void)interruptionStarted {}
- (void)recordPermissionRefused {}
- (void)mapChannels:(multiOutputChannelMap *)outputMap inputMap:(multiInputChannelMap *)inputMap externalAudioDeviceName:(NSString *)externalAudioDeviceName outputsAndInputs:(NSString *)outputsAndInputs {}
- (void)interruptionEnded { // If a player plays Apple Lossless audio files, then we need this. Otherwise unnecessary.
playerA->onMediaserverInterrupt();
}
#end
Project-Bridging-Header.h:
#import "Superpowered.h"
Controller.swift:
override func viewDidLoad() {
super.viewDidLoad()
let s = Superpowered();
s.f();
}
When running the app it crashes and gives the following error:

Answer 1

let s = Superpowered(); should be declared outside viewDidLoad(). Declaring it as an instance variable solved the problem.