源码:
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
- // 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 10
- struct ret_value
- {
- unsigned charchar *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 = 11 * 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 charchar *fname, struct ret_value *ret)
- {
- NSLog(@"%s: %d", __func__, __LINE__);
- FILEFILE *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 charchar *)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