【IOS】获取麦克风数据来绘制声音的波形

1.头文件;

#import <AVFoundation/AVFoundation.h>

代理 <AVCaptureAudioDataOutputSampleBufferDelegate>

2.新建属性;

@property(strong,nonatomic) AVCaptureSession *captureSession;//数据传递

@property(strong,nonatomic) AVCaptureDeviceInput *captureDeviceInput;//输入数据

@property(strong,nonatomic) AVCaptureAudioDataOutput *captureAudioDataOutput;//声音输出

3.初始化数据;

- (void)initAudio{

_captureSession = [[AVCaptureSession alloc]init];

AVAudioSession *audioSession = [AVAudioSession sharedInstance];

[audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];

[audioSession setActive:YES error:nil];

NSError *error = nil;

AVCaptureDevice *audioDev = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];

AVCaptureDeviceInput *audioIn = [[AVCaptureDeviceInput alloc]initWithDevice:audioDev error:&error];

if ([_captureSession canAddInput:audioIn]) {

[_captureSession addInput:audioIn];

}

_captureAudioDataOutput = [[AVCaptureAudioDataOutput alloc] init];

if([_captureSession canAddOutput:_captureAudioDataOutput]) {

[_captureSession addOutput:_captureAudioDataOutput];

//指定代理 增加并行线程

dispatch_queue_t queue = dispatch_queue_create("myQueue",DISPATCH_QUEUE_SERIAL);

[_captureAudioDataOutput setSampleBufferDelegate:self queue:queue];

[_captureAudioDataOutput connectionWithMediaType:AVMediaTypeAudio];

}}

4.处理代理事件;

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection{

NSMutableArray *dataArr = [[NSMutableArray alloc]init];

AudioBufferList audioBufferList;

CMBlockBufferRef blockBuffer;

CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(sampleBuffer, NULL, &audioBufferList, sizeof(audioBufferList), NULL, NULL, 0, &blockBuffer);

//将数据块转换成点

for( int y=0; y< audioBufferList.mNumberBuffers; y++ ){

AudioBuffer audioBuffer = audioBufferList.mBuffers[y];

Byte *frame = (Byte *)audioBuffer.mData;

int d = audioBuffer.mDataByteSize/2;

for(long i=0; i<d; i++)
{

long x1 = frame[i*2+1]<<8;

long x2 = frame[i*2];

short int w = x1 | x2;

float x = 10.0 + i * (self.showView.frame.size.width - 20) / d;

float y = self.showView.frame.size.height/2.0f+ (self.showView.frame.size.height*0.5) * (w > 32767.0?32767.0:w) / 32767.0 ;

NSValue *pValue = [NSValue valueWithCGPoint:CGPointMake(x, y)];

[dataArr addObject:pValue];

}

}

CFRelease(blockBuffer);

self.pointArr = [NSMutableArray arrayWithArray:dataArr];

}

5.绘制图形;

-(void)drawRect:(CGRect)rect{

[super drawRect:rect];

if (!self.mpointArr) {

return;

}

CGContextRef context = UIGraphicsGetCurrentContext();

[[UIColor blueColor] setStroke];

CGContextSetLineWidth(context, 1.0);

CGContextBeginPath(context);

CGContextMoveToPoint(context, 0, self.frame.size.height/2.0);

for (int i = 0; i < [self.mpointArr count]; i++) {

CGPoint point = [self.mpointArr[i] CGPointValue];

CGContextAddLineToPoint(context, point.x, point.y);}

CGContextAddLineToPoint(context, ScreenWidth, self.frame.size.height/2.0);

CGContextStrokePath(context);

}

6.加定时器,每0.05S绘制一次;

reloadTime = [NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:@selector(reloadState:) userInfo:nil repeats:YES];

[[NSRunLoop mainRunLoop] addTimer:reloadTime forMode:NSRunLoopCommonModes];

- (void)reloadState:(NSTimer *)t{

if (self.pointArr) {

sView.mpointArr = [NSMutableArray arrayWithArray:self.pointArr];

[sView setNeedsDisplay];

}

}

debug模式 有些卡的 直接运行就好了

https://github.com/huasali/VoiceDemo