iOS 画平滑曲线的方法及取音频数据的方法

取音频数据和画波形图的方法

ViewController.h

////  ViewController.h//  iOS心电图Demo////  Created by 杜甲 on 13-10-18.//  Copyright (c) 2013年 杜甲. All rights reserved.//#import <UIKit/UIKit.h>#import "HLSonogramView.h"@interface ViewController : UIViewController@property (strong, nonatomic) HLSonogramView* hlSonogramView;@end

ViewController.m

////  ViewController.m//  iOS心电图Demo////  Created by 杜甲 on 13-10-18.//  Copyright (c) 2013年 杜甲. All rights reserved.//#import "ViewController.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad{    [super viewDidLoad];// Do any additional setup after loading the view, typically from a nib.        self.hlSonogramView = [[HLSonogramView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];            [self.view addSubview:self.hlSonogramView];}- (void)didReceiveMemoryWarning{    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end

HLSonogramView.h

////  HLSonogramView.h//  iOS心电图Demo////  Created by 杜甲 on 13-10-18.//  Copyright (c) 2013年 杜甲. All rights reserved.//#import <UIKit/UIKit.h>#define kMaxKeyPoints  1000#define kHillSegmentWidth 10struct ret_value{    unsigned char *data;//注意这里是unsigned char    unsigned long int size;};@interface HLSonogramView : UIView{     CGPoint m_pSonogramKeyPoint[kMaxKeyPoints];}@property (assign ,nonatomic) float m_pOffsetX;@property (assign ,nonatomic) int m_pSonogramKeyPointNum;//转换后的座标数据，用于绘制波形图@property (nonatomic, strong) NSMutableArray *m_pointWavArray;@end

HLSonogramView.m

////  HLSonogramView.m//  iOS心电图Demo////  Created by 杜甲 on 13-10-18.//  Copyright (c) 2013年 杜甲. All rights reserved.//#import "HLSonogramView.h"#define ScreenHeight [[UIScreen mainScreen] bounds].size.height#define ScreenWidth [[UIScreen mainScreen] bounds].size.width@implementation HLSonogramView- (id)initWithFrame:(CGRect)frame{    self = [super initWithFrame:frame];    if (self) {        // Initialization code        self.backgroundColor = [UIColor whiteColor];        [self generatePoint];    }    return self;}-(void)drawRect:(CGRect)rect{    [super drawRect:rect];    CGContextRef context = UIGraphicsGetCurrentContext();    CGContextSetLineCap(context, kCGLineCapSquare);    CGContextSetLineWidth(context, 1.0);    CGContextSetRGBStrokeColor(context, 1.0, 0.0, 0.0, 1.0);    CGContextBeginPath(context);    CGContextMoveToPoint(context, 0, ScreenHeight / 2);    for (int i = 1; i < kMaxKeyPoints; i++) {                CGPoint p0 = m_pSonogramKeyPoint[i - 1];        CGPoint p1 = m_pSonogramKeyPoint[i];                int hSegments = floorf((p1.x - p0.x) / kHillSegmentWidth);        float dx = (p1.x - p0.x) / hSegments;        float da = M_PI / hSegments;        float ymid = (p0.y + p1.y) / 2;        float ampl = (p0.y - p1.y) / 2;                        CGPoint pt0,pt1;        pt0 = p0;        for (int j = 0; j < hSegments + 1; ++j) {            pt1.x = p0.x + j * dx;            pt1.y = ymid + ampl * cosf(da * j);            CGContextAddLineToPoint(context, pt0.x, pt0.y);            CGContextAddLineToPoint(context, pt1.x, pt1.y);            pt0 = pt1;        }       }    CGContextStrokePath(context);}-(void)generatePoint{    float m_pWinHeight = ScreenHeight;    float m_pWinWidth  = ScreenWidth;            float x  = 0;    float y = m_pWinHeight / 2;           for (int i = 0; i < kMaxKeyPoints; ++i) {        m_pSonogramKeyPoint[i] = CGPointMake(x, y);        x += m_pWinWidth / 2;        y = rand() % (int)m_pWinHeight;    }}//取音频数据- (void)transformDateOFWavFromFile{    NSString *path = [[NSBundle mainBundle] pathForResource:@"1" ofType:@"wav"];    struct ret_value ret;    load_wave_file([path UTF8String], &ret);    //  printf("data.size = %lu\n", ret.size);        int d = ret.size / 2;    short int wave_data[d];    for(long i=0; i<d; i++)    {        short int w = (ret.data[i*2+1]<<8) | ret.data[i*2];        //printf("%d\n", w);        wave_data[i] = w;    }        int myLineSize = d;        //--添加成员变量-方便外部调用----    CGPoint myLines[myLineSize];    self.m_pointWavArray = [NSMutableArray arrayWithCapacity:8];        //for(int i=0;i<myLineSize;i++)    //{    //    myLines[i]=CGPointMake(10+i, [self getRandomNumber:200 to:400]);    //}    //    for (int i = 0; i < d; i++) {    //        NSLog(@"wave_data[i] = %hd",wave_data[i]);    //    }        for (int i = 0; i < d ; i++) {        float x = 1 * i;        float y = 47.75 + wave_data[i] / 1000;        if (y < 5) {            y = 5;        }        if (y > 92.5) {            y = 92.5;        }        myLines[i] = CGPointMake(x, y);        NSValue *pValue = [NSValue valueWithCGPoint:myLines[i]];        [self.m_pointWavArray addObject:pValue];    }        //    for(int i=0;i<d;i++)    //    {    //        float x = 10.0 + i * 300.0 / d;    //        float y = 85+ 200.0 * wave_data[i] / 12767.0 ;    //       // printf("x=%f, y=%f\n", x, y);    //        myLines[i] = CGPointMake(x, y);    //    //        //---存放到波形图的点数组中----------------    //        NSValue *pValue = [NSValue valueWithCGPoint:myLines[i]];    //        [self.m_pointWavArray addObject:pValue];    //    }    NSLog(@"%@",self.m_pointWavArray);    }void load_wave_file(const char *fname, struct ret_value *ret){    NSLog(@"%s: %d", __func__, __LINE__);        FILE *fp;    fp = fopen(fname, "rb");    if(fp)    {        char id[5];        unsigned long size;        short format_tag, channels, block_align, bits_per_sample;//16 bit data        unsigned long format_length, sample_rate, avg_bytes_sec, data_size;//32 bit data                fread(id, sizeof(char), 4, fp);        id[4]='\0';        if (!strcmp(id, "RIFF"))        {            fread(&size, sizeof(unsigned long), 1, fp);//read file size            fread(id, sizeof(char), 4, fp);//read wave            id[4]='\0';                        if (!strcmp(id, "WAVE"))            {                fread(id, sizeof(char), 4, fp);//读取4字节"fmt"                fread(&format_length, sizeof(unsigned long), 1, fp);                fread(&format_tag, sizeof(short), 1, fp);//读取文件tag                fread(&channels, sizeof(short), 1, fp);//读取通道数目                fread(&sample_rate, sizeof(unsigned long), 1, fp);//读取采样率大小                fread(&avg_bytes_sec, sizeof(unsigned long), 1, fp);//读取每秒数据量                fread(&block_align, sizeof(short), 1, fp);//读取块对齐                fread(&bits_per_sample, sizeof(short), 1, fp);//读取每一样本大小                fread(id, sizeof(char), 4, fp);//读取data                fread(&data_size, sizeof(unsigned long), 1, fp);                ret->size = data_size;                ret->data = (unsigned char *)malloc(sizeof(char)*data_size);//申请内存空间                fread(ret->data, sizeof(char), data_size, fp);//读取数据                                printf("bits_per_sample = %d\n", bits_per_sample);                printf("channels = %d\n", channels);                printf("sample_rate = %lu\n", sample_rate);            }else{                printf("Error: RIFF file but not a wave file\n");            }        }else{            printf("Error: not a RIFF file\n");        }        fclose(fp);    }}@end

本文代码例子：http://pan.baidu.com/s/1xKgIX