| 网站首页 | 业界新闻 | 群组 | 交易 | 人才 | 下载频道 | 博客 | 代码贴 | 在线编程 | 编程论坛
跟大牛学C++学算法数据结构
共有 341 人关注过本帖
标题:c语言实现滤波器
只看楼主 加入收藏
yoshio
Rank: 1
等 级:新手上路
帖 子:2
专家分:0
注 册:2019-1-2
结帖率:0
  已结贴   问题点数:20  回复次数:4   
c语言实现滤波器
         
        我写了很久了,但是新手上路问题巨多,实在不知道怎么解决。用matlab实验后发现滤波的函数没有问题,主要问题出在wav文件data块数据的提取上,具体问题在下面,求大佬拯救。(代码没整理,逻辑混乱,看看就好...)


滤波器设计和使用
一、实验目的和任务:
实验目的:
练习随机数、静态局部变量、滤波器等知识的综合运用;
培养学生综合运用C程序语言进行程序设计的能力;
培养结构化程序设计能力;
实验任务:

实验内容:
完成随机数产生函数:double RandDouble(double Max),即生产0到Max之间的随机数,且返回的随机数带2位小数,如6.28等;
编写一函数,double filter(double x);实现如下功能:输入xi,输出yi,其中xi的定义如5-1所示,即i大于0时,为随机数,小于0时为0,i为整数;xi和yi的关系如5-2所示。
             (5-1)
        (5-2)
c0,c1,c2,c3,c4的值分别为常数:0.01,0.1, 0.78,  0.1,  0.01,请用宏定义c0到c4的值;rand()为随机数函数,产生随机数整数;
写一主函数,在主函数中调用随机数生成函数,产生序列x,并求出序列y的值,输出x和y的值。
设Cn为某低通滤波器系数,Cn的值见后。改写double filter(double x)函数,实现滤波功能。编写主函数,读取一个被噪声污染的语音文件,并进行滤波处理,把处理后的文件保存下来,并进行试听,观察处理效果。



#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#define p 101
double *s;
char *temp;
char *temp_2;
unsigned short int *data;
short int *data_11;
double *data_1;
double *data_2;
unsigned short int * data_3;
short int * data_33;
double fir_filt(double x, double *b, double *, int);
typedef struct _tagMsWavPcmHeader44
{
    unsigned char ChunkID[4]; // "RIFF"; The "RIFF" the mainchunk;
    unsigned long ChunkSize; // FileSize - 8; The size following this data
    unsigned char Format[4];
// "WAVE"; The "WAVE" format consists of two subchunks: "fmt " and "data"
    unsigned char SubChunk1ID[4]; // "fmt "
    unsigned long SubChunk1Size;
// 16 for PCM. This is the size of the rest of the subchunk which follows this data.
    unsigned short AudioFormat; // 1 for PCM. Linear quantization
    unsigned short NumChannels; // 1->Mono, 2->stereo, etc..
    unsigned long SampleRate; // 8000, 11025, 16000, 44100, 48000, etc..
    unsigned long ByteRate; // = SampleRate * NumChannels * BitsPerSample/8
    unsigned short BlockAlign; // = NumChannels * BitsPerSample / 8
    unsigned short BitsPerSample; // 8->8bits, 16->16bits, etc..
    unsigned char SubChunk2ID[4]; // "data"
    unsigned long SubChun2Size;
// = NumSamples * NumChannels * BitsPerSample / 8. The size of data
} wav_pcm_header44; //44
double randdouble(double Max);
double filter(double * x,int i);
//double c[5]= {0.01,0.1,0.78,0.1,0.01};
double c[101] = {-0.004808919657970,
                 -0.001547991286813,
                 -0.001484119075616,
                 -0.001180626535065,
                 -0.000638610828712,
                 0.000104137685310,
                 0.000976202943056,
                 0.001875083276187,
                 0.002678747868229,
                 0.003258340856584,
                 0.003497633328625,
                 0.003310022925111,
                 0.002656136525684,
                 0.001555093457088,
                 0.000095231399231,
                 -0.001579126147775,
                 -0.003267487272886,
                 -0.004745069573984,
                 -0.005784364014156,
                 -0.006183187126704,
                 -0.005799711899067,
                 -0.004575941863646,
                 -0.002560489731262,
                 0.000086215276100,
                 0.003095941733918,
                 0.006123608643356,
                 0.008773450587629,
                 0.010645725379523,
                 0.011369883796541,
                 0.010707969201656,
                 0.008534221934017,
                 0.004906086245703,
                 0.000084923610347,
                 -0.005500640536805,
                 -0.011244701868107,
                 -0.016442739558196,
                 -0.020332177216741,
                 -0.022189237562184,
                 -0.021388750352397,
                 -0.017496131711919,
                 -0.010310727721149,
                 0.000074954684212,
                 0.013283855664295,
                 0.028642402846373,
                 0.045253402410963,
                 0.062043759242903,
                 0.077862333668155,
                 0.091580983706917,
                 0.102191837897796,
                 0.108897201849955,
                 0.111190826178577,
                 0.108897201849955,
                 0.102191837897796,
                 0.091580983706917,
                 0.077862333668155,
                 0.062043759242903,
                 0.045253402410963,
                 0.028642402846373,
                 0.013283855664295,
                 0.000074954684212,
                 -0.010310727721149,
                 -0.017496131711919,
                 -0.021388750352397,
                 -0.022189237562184,
                 -0.020332177216741,
                 -0.016442739558196,
                 -0.011244701868107,
                 -0.005500640536805,
                 0.000084923610347,
                 0.004906086245703,
                 0.008534221934017,
                 0.010707969201656,
                 0.011369883796541,
                 0.010645725379523,
                 0.008773450587629,
                 0.006123608643356,
                 0.003095941733918,
                 0.000086215276100,
                 -0.002560489731262,
                 -0.004575941863646,
                 -0.005799711899067,
                 -0.006183187126704,
                 -0.005784364014156,
                 -0.004745069573984,
                 -0.003267487272886,
                 -0.001579126147775,
                 0.000095231399231,
                 0.001555093457088,
                 0.002656136525684,
                 0.003310022925111,
                 0.003497633328625,
                 0.003258340856584,
                 0.002678747868229,
                 0.001875083276187,
                 0.000976202943056,
                 0.000104137685310,
                 -0.000638610828712,
                 -0.001180626535065,
                 -0.001484119075616,
                 -0.001547991286813,
                 -0.004808919657970
                };
int main(void)
{
    s=(double *)malloc(sizeof(double) * 100);
    srand(time(0));
    wav_pcm_header44 wav;
    FILE * fp,*save;
    save=fopen("save.wav","wb");
    fp=fopen("test.wav","rb");
    if (!fp)
    {
        printf("can't open audio file\n");
        exit(1);
    }
    fseek(fp,0L,SEEK_END);
    int f=ftell(fp);
    //printf("%d,\n",f);
    rewind(fp);
    fread(&wav,sizeof(wav_pcm_header44),1,fp);
    fwrite(&wav,sizeof(wav_pcm_header44),1,save);
    printf("ChunkID=%c%c%c%c\n",wav.ChunkID[0],wav.ChunkID[1],wav.ChunkID[2],wav.ChunkID[3]);
    printf("ChunkSize=%ld\n",wav.ChunkSize);
    printf("Format=%c%c%c%c\n",wav.Format[0],wav.Format[1],wav.Format[2],wav.Format[3]);
    printf("SubChunk1ID=%c%c%c%c\n",wav.SubChunk1ID[0],wav.SubChunk1ID[1],wav.SubChunk1ID[2],wav.SubChunk1ID[3]);
    printf("SubChunk1Size=%ld\n",wav.SubChunk1Size);
    printf("AudioFormat=%hd\n",wav.AudioFormat);
    printf("NumChannels=%hd\n",wav.NumChannels);
    printf("SampleRate=%ld\n",wav.SampleRate);
    printf("ByteRate=%ld\n",wav.ByteRate);
    printf("BlockAlign=%hd\n",wav.BlockAlign);
    printf("BitsPerSample=%hd\n",wav.BitsPerSample);
    printf("SubChunk2ID=%c%c%c%c\n",wav.SubChunk2ID[0],wav.SubChunk2ID[1],wav.SubChunk2ID[2],wav.SubChunk2ID[3]);
    printf("SubChunk2Size=%ld\n",wav.SubChun2Size);
    setvbuf(fp,0,_IOFBF,BUFSIZ);
    temp=(char *)malloc(sizeof(char)*f);
    temp_2=(char *)malloc(sizeof(char)*f);
    data=(unsigned short int *)malloc(sizeof(unsigned short int )*f/2);
    data_1=(double *)malloc(sizeof(double) * f/2);
    data_2=(double *)malloc(sizeof(double) * f/2);
    data_3=(unsigned short int *)malloc(sizeof(unsigned short int )*f/2);
    data_11=(short int *)malloc(sizeof(short int )*f/2);
    data_33=(short int *)malloc(sizeof(short int )*f/2);
    fread(temp,sizeof(char),f,fp);
    for(int i=0; i < f/2; i++)
    {
        data_11[i]=(short int)(temp[2*i]&0xff)*256+(temp[2*i+1]&0xff);
        data_1[i]=(double)data_11[i]/32768;
    }
    for(int i=0 ;i<100;i++)
    {
       s[i]=data_1[i+1];
    }
    for(int i=0; i < f/2; i++)
    {
        data_2[i]=fir_filt(data_1[i],c,s,101);
        //printf("%lf,",data_2[i]);
        data_33[i]=data_2[i]*32768;
        //data_33[i]=data_11[i]+32768;

    }

    for(int i=0; i < f/2; i++)
    {
        temp_2[2*i+1]=data_33[i]&0xff;
        temp_2[2*i]=(data_33[i]>>8)&0xff;
        //printf("%hd,",temp[i]-temp_2[i]);
    }

    fwrite(temp_2,sizeof(char),f,save);
    fclose(fp);
    fclose(save);
}
double randdouble(double _max)
{
    unsigned long int temp=rand()%(unsigned long int)(_max*100)+1;
    return (double)(temp*0.01);
}
double filter(double * x,int i)
{
    double ret=0;
    for(int n=0; n<=p; n++)
    {
        if((i-n)>0)
        {
            ret+=c[n]*x[i-n];
        }
    }

    return ret;
}
double fir_filt(double x, double *b, double *s_, int p_)
{
    double y = b[0] * x;
    for(int i = 0; i < p_-1; i++)
        y += b[i+1] * s_[i];
    for(int j = p_-1; j > 0; j--)
        s_[j] = s_[j-1];
    s_[0] = x;
    //printf("%lf,",y-x);
    return y;
}
2019-01-02 08:41
wp231957
Rank: 20Rank: 20Rank: 20Rank: 20Rank: 20
来 自:神界
等 级:版主
威 望:376
帖 子:13088
专家分:50627
注 册:2012-10-18
  得分:10 
没看明白你想问神马

DO IT YOURSELF !
2019-01-02 11:01
yoshio
Rank: 1
等 级:新手上路
帖 子:2
专家分:0
注 册:2019-1-2
  得分:0 
你可以当我啥也不会直接看题。。。
2019-01-02 12:07
吕孟伟
Rank: 2
等 级:论坛游民
威 望:1
帖 子:28
专家分:48
注 册:2018-10-4
  得分:10 
我能插个嘴么,一般新手写不出来这玩意!
2019-01-03 14:14
anwf
Rank: 1
等 级:新手上路
帖 子:1
专家分:0
注 册:2019-1-11
  得分:0 
ss
2019-01-11 17:12







关于我们 | 广告合作 | 编程中国 | 清除Cookies | TOP | 手机版

编程中国 版权所有,并保留所有权利。
Powered by Discuz, Processed in 0.051872 second(s), 9 queries.
Copyright©2004-2019, BCCN.NET, All Rights Reserved