/
AudioSignalGenerator.m
163 lines (118 loc) · 2.9 KB
/
AudioSignalGenerator.m
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//
// AudioSignalGenerator.m
// FSK Terminal
//
// Created by George Dean on 1/6/09.
// Copyright 2009 Perceptive Development. All rights reserved.
//
#include <AudioToolbox/AudioToolbox.h>
#import "AudioQueueObject.h"
#import "AudioSignalGenerator.h"
static void playbackCallback (
void *inUserData,
AudioQueueRef inAudioQueue,
AudioQueueBufferRef bufferReference
) {
// This is not a Cocoa thread, it needs a manually allocated pool
// NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
// This callback, being outside the implementation block, needs a reference to the AudioSignalGenerator object
AudioSignalGenerator *player = (AudioSignalGenerator *) inUserData;
if ([player stopped]) return;
[player fillBuffer:bufferReference->mAudioData];
bufferReference->mAudioDataByteSize = player.bufferByteSize;
AudioQueueEnqueueBuffer (
inAudioQueue,
bufferReference,
player.bufferPacketCount,
player.packetDescriptions
);
// [pool release];
}
@implementation AudioSignalGenerator
@synthesize packetDescriptions;
@synthesize bufferByteSize;
@synthesize bufferPacketCount;
@synthesize stopped;
@synthesize audioPlayerShouldStopImmediately;
- (id) init {
self = [super init];
if (self != nil) {
[self setupAudioFormat];
[self setupPlaybackAudioQueueObject];
self.stopped = NO;
self.audioPlayerShouldStopImmediately = NO;
}
return self;
}
- (void) setupAudioFormat {
}
- (void) fillBuffer: (void*) buffer
{
}
- (void) setupPlaybackAudioQueueObject {
// create the playback audio queue object
AudioQueueNewOutput (
&audioFormat,
playbackCallback,
self,
nil,
nil,
0, // run loop flags
&queueObject
);
AudioQueueSetParameter (
queueObject,
kAudioQueueParam_Volume,
1.0f
);
}
- (void) setupAudioQueueBuffers {
// prime the queue with some data before starting
// allocate and enqueue buffers
int bufferIndex;
for (bufferIndex = 0; bufferIndex < 3; ++bufferIndex) {
AudioQueueAllocateBuffer (
[self queueObject],
[self bufferByteSize],
&buffers[bufferIndex]
);
playbackCallback (
self,
[self queueObject],
buffers[bufferIndex]
);
if ([self stopped]) break;
}
}
- (void) play {
[self setupAudioQueueBuffers];
AudioQueueStart (
self.queueObject,
NULL // start time. NULL means ASAP.
);
}
- (void) stop {
AudioQueueStop (
self.queueObject,
self.audioPlayerShouldStopImmediately
);
}
- (void) pause {
AudioQueuePause (
self.queueObject
);
}
- (void) resume {
AudioQueueStart (
self.queueObject,
NULL // start time. NULL means ASAP
);
}
- (void) dealloc {
AudioQueueDispose (
queueObject,
YES
);
[super dealloc];
}
@end