WaveForm on IOS

Question

I\'m looking for how to draw the sound amplitude.

I found http://supermegaultragroovy.com/2009/10/06/drawing-waveforms/ but i have some problems. How get a list of f

Answer 1

this is my answer, thx all geek

obj-c

here is code:

-(void) listenerData:(NSNotification *) notify
{
int resnum=112222;
unsigned int bitsum=0;
for(int i=0;i<4;i++)
{
    bitsum+=(resnum>>(i*8))&0xff;
}
bitsum=bitsum&0xff;
NSString * check=[NSString stringWithFormat:@"%x %x",resnum,bitsum];
check=nil; 
self.drawData=notify.object;``
[self setNeedsDisplay];
}

-(void)drawRect:(CGRect)rect
{
NSArray *data=self.drawData;
NSData *tdata=[data objectAtIndex:0];
double *srcdata=(double*)tdata.bytes;
int datacount=tdata.length/sizeof(double);
tdata=[data objectAtIndex:1];
double *coveddata=(double*)tdata.bytes;

CGContextRef context=UIGraphicsGetCurrentContext();
CGRect bounds=self.bounds;
CGContextClearRect(context, bounds);
CGFloat midpos=bounds.size.height/2;
CGContextBeginPath(context);

const double scale=1.0/100;
CGFloat step=bounds.size.width/(datacount-1);
CGContextMoveToPoint(context, 0, midpos);
CGFloat xpos=0;
for(int i=0;i