这个函数不知道怎么调用,谁能帮帮我这个小菜鸟呢

满衣兄 2009-05-26 03:00:30
我这里有个FFT的类,可是我不会使用.郁闷.
我是这么调用的:


//srcBuf:是编码之后的语音数据,从网络接收过来的.

//dstBuf:是解码之后的语音数据

//len:是解码之后的语音数据长度=480

bool RTPRecv::DecodeData(char *srcBuf,char *dstBuf,int &len)

{

	//......

	//......省略N行,主要是对语音数据解码的,解码之后的数据放在dstBuf里,len=480

	//......

	//......

	CFastFourier *p_myFourier = new CFastFourier();

	float	xreal[N_ARRAY] = {0};

	for (int i=0;i<len;i++)

	{

		xreal[i] = (float)dstBuf[i];

	}

	float	ximag[N_ARRAY] = {0};

	p_myFourier->FFT(xreal, ximag, len);

	p_myFourier->IFFT(xreal, ximag, len);



	for (int k=0; k<len; k++)

	{

		dstBuf[k] = (char)ximag[k];

	}

	delete p_myFourier;

	p_myFourier = NULL;

}


大家帮忙看看这么调用对不对啊?fft_ifft.cpp在网上找的.如果我不进行fft变换声音是正常的,变换之后就全是杂音了.

我应该怎么调用这个类呢?郁闷.


类定义如下:
fft_ifft.h


#pragma once

#define N_ARRAY	1024

#define PI		3.1416



class CFastFourier

{

public:

	CFastFourier();

	virtual ~CFastFourier();



	void swap(float* a, float* b);

	void bitrp(float* xreal, float* ximag, int n);

	void FFT(float* xreal, float* ximag, int n);

	void IFFT(float* xreal, float* ximag, int n);

};


fft_ifft.cpp


#include "stdafx.h"

#include <stdio.h>

#include <stdlib.h>

#include <math.h>

#include "fft_ifft.h"



CFastFourier::CFastFourier()

{



}



CFastFourier::~CFastFourier()

{



}



void CFastFourier::swap(float* a, float* b)

{

    float t;

    

	 t	= *a;

    *a	= *b;

	*b	=  t;

}



void CFastFourier::bitrp(float* xreal, float* ximag, int n)

{

 	int i, j, a, b, p;



	for (i = 1, p = 0; i < n; i *= 2)

    {

		p++;

    }

	

	for (i = 0; i < n; i ++)

    {

		a = i;

		b = 0;

		

		for (j = 0; j < p; j ++)

        {

			b = (b << 1) + (a & 1);    // b = b * 2 + a % 2;

			a >>= 1;        // a = a / 2;

        }

		

		if ( b > i)

        {

			swap(&xreal[i], &xreal[b]);

			swap(&ximag[i], &ximag[b]);

        }

     }

}





void CFastFourier::FFT(float* xreal, float* ximag, int n)

{

	float	wreal [N_ARRAY / 2], wimag [N_ARRAY / 2], treal, timag, ureal, uimag;

	double	arg;

    int		m, k, j, t, index1, index2;

     

    bitrp (xreal, ximag, n);

      

    arg			= -2 * PI / n;

    treal		= (float)cos(arg);

    timag		= (float)sin(arg);

    wreal [0]	= 1.0;

    wimag [0]	= 0.0;

     

	for (j = 1; j < n / 2; j ++)

    {

		wreal[j] = wreal[j - 1] * treal - wimag[j - 1] * timag;

		wimag[j] = wreal[j - 1] * timag + wimag[j - 1] * treal;

	}

 

    for (m = 2; m <= n; m *= 2)

    {

		for (k = 0; k < n; k += m)

        {

			for (j = 0; j < m / 2; j ++)

            {

				index1 = k + j;

                index2 = index1 + m / 2;

                t = n * j / m;

                treal = wreal[t] * xreal[index2] - wimag[t] * ximag[index2];

                timag = wreal[t] * ximag[index2] + wimag[t] * xreal[index2];

                ureal = xreal[index1];

                uimag = ximag[index1];

                xreal[index1] = ureal + treal;

                ximag[index1] = uimag + timag;

                xreal[index2] = ureal - treal;

                ximag[index2] = uimag - timag;

            }

        }

    }

}





void CFastFourier::IFFT(float* xreal, float* ximag, int n)

{

	float	wreal [N_ARRAY / 2], wimag [N_ARRAY / 2], treal, timag, ureal, uimag;

	double	arg;

    int		m, k, j, t, index1, index2;

     

    bitrp (xreal, ximag, n);

    

    arg			= 2 * PI / n;

    treal		= (float)cos(arg);

    timag		= (float)sin(arg);

    wreal[0]	= 1.0;

    wimag[0]	= 0.0;

    

	for (j = 1; j < n / 2; j ++)

	{

		wreal[j] = wreal[j - 1] * treal - wimag[j - 1] * timag;

        wimag[j] = wreal[j - 1] * timag + wimag[j - 1] * treal;

    }

 

    for (m = 2; m <= n; m *= 2)

	{

        for (k = 0; k < n; k += m)

		{

			for (j = 0; j < m / 2; j ++)

            {

				index1 = k + j;

                index2 = index1 + m / 2;

                t = n * j / m;

                treal = wreal[t] * xreal[index2] - wimag[t] * ximag[index2];

                timag = wreal[t] * ximag[index2] + wimag[t] * xreal[index2];

                ureal = xreal[index1];

                uimag = ximag[index1];

                xreal[index1] = ureal + treal;

                ximag[index1] = uimag + timag;

                xreal[index2] = ureal - treal;

                ximag[index2] = uimag - timag;

            }

        }

	}

 

	for (j=0; j < n; j ++)

    {

		xreal[j] /= n;

        ximag[j] /= n;

	}

}
...全文
320 36 打赏 收藏 转发到动态 举报
写回复
用AI写文章
36 条回复
切换为时间正序
请发表友善的回复…
发表回复
lzh9955 2009-05-27
  • 打赏
  • 举报
 回复
一步步来！
满衣兄 2009-05-27
  • 打赏
  • 举报
 回复
有谁知道怎么使用的吗?郁闷
goodname 2009-05-27
  • 打赏
  • 举报
 回复
瞎猜不行，要么搞定算法，要么请做过这个东西的人。


哎，到处都这么困难。
goodname 2009-05-27
  • 打赏
  • 举报
 回复
要是严格按照上面的来还应该
for (int i=0;i<512;i++)
{
yreal[i] = (float)tmp[i];
}

满衣兄 2009-05-27
  • 打赏
  • 举报
 回复
[Quote=引用 32 楼 goodname 的回复:]
30楼有例子，使用28,29楼的文件。
[/Quote]
还是不行啊


double    xreal[N_ARRAY] = {0}, ximag[N_ARRAY] = {0}; 

	double    yreal[N_ARRAY] = {0}, yimag[N_ARRAY] = {0}; 

	double    zreal[N_ARRAY] = {0}, zimag[N_ARRAY] = {0};



	char tmp[N_ARRAY] = {0};

	memcpy(tmp,dstBuf,len);

	for (int i=0;i<512;i++)

	{

		xreal[i] = (float)tmp[i];

	}



	p_myFourier->fft_conv( xreal, ximag, yreal, yimag, zreal, zimag, 512 );

	p_myFourier->roundoff( zreal, 512 );



	for (int k=0; k<len; k++)

	{

		//dstBuf[k] = (char)zreal[k];//这样什么声音都没有

		dstBuf[k] = (char)xreal[k];//这样全是杂音

	}
Qlaiaqu 2009-05-27
  • 打赏
  • 举报
 回复
引来大牛无数阿
goodname 2009-05-27
  • 打赏
  • 举报
 回复
30楼有例子，使用28,29楼的文件。
满衣兄 2009-05-27
  • 打赏
  • 举报
 回复
[Quote=引用 28 楼 goodname 的回复:]
fft_ifft.h

C/C++ code
#define N_ARRAY 1024
#define PI 3.1416

class CFastFourier
{
public:
CFastFourier();
virtual ~CFastFourier();

void swap(double* a, double* b);
void bitrp(double* xreal, double* ximag, int n);
void FFT(double* xreal, double* ximag, int n);
void IFFT(double* xreal, double* ximag, int n);
void roundoff(double* zreal, int…
[/Quote]
怎么使用啊,fft_conv各个参数是什么意思
goodname 2009-05-27
  • 打赏
  • 举报
 回复
example.cpp



	CFastFourier* p_myFourier = new CFastFourier();



	double	xreal[N_ARRAY] = {0}, ximag[N_ARRAY] = {0}; 

	double	yreal[N_ARRAY] = {0}, yimag[N_ARRAY] = {0}; 

	double	zreal[N_ARRAY] = {0}, zimag[N_ARRAY] = {0};

				

	xreal[0]	=  1.0f;

	xreal[1]	=  2.0f;

	xreal[2]	=  3.0f;

	xreal[3]	=  4.0f;

	

	yreal[0]	=  1.0f;

	yreal[1]	=  2.0f;

	yreal[2]	=  3.0f;

	yreal[3]	=  4.0f;

			

	p_myFourier->fft_conv( xreal, ximag, yreal, yimag, zreal, zimag, 8 );

	p_myFourier->roundoff( zreal, 8 );

		

	delete p_myFourier;

	p_myFourier = NULL;
goodname 2009-05-27
  • 打赏
  • 举报
 回复
fft_ifft.h


#include <stdio.h>

#include <stdlib.h>

#include <math.h>

#include "fft_ifft.h"



CFastFourier::CFastFourier()

{



}



CFastFourier::~CFastFourier()

{



}



void CFastFourier::swap(double* a, double* b)

{

    double t;

    

	 t	= *a;

    *a	= *b;

	*b	=  t;

}



void CFastFourier::bitrp(double* xreal, double* ximag, int n)

{

 	int i, j, a, b, p;



	for (i = 1, p = 0; i < n; i *= 2)

		p++;

    	

	for (i = 0; i < n; i ++)

    {

		a = i;

		b = 0;

		

		for (j = 0; j < p; j ++)

        {

			b = (b << 1) + (a & 1);	// b = b * 2 + a % 2;

			a >>= 1;				// a = a / 2;

        }

		

		if ( b > i)

        {

			swap(&xreal[i], &xreal[b]);

			swap(&ximag[i], &ximag[b]);

        }

     }

}





void CFastFourier::FFT(double* xreal, double* ximag, int n)

{

	double	wreal [N_ARRAY / 2], wimag [N_ARRAY / 2], treal, timag, ureal, uimag;

	double	arg;

    int		m, k, j, t, index1, index2;

     

    bitrp (xreal, ximag, n);

      

    arg			= -2 * PI / n;

    treal		= cos(arg);

    timag		= sin(arg);

    wreal [0]	= 1.0;

    wimag [0]	= 0.0;

     

	for (j = 1; j < n / 2; j ++)

    {

		wreal[j] = wreal[j - 1] * treal - wimag[j - 1] * timag;

		wimag[j] = wreal[j - 1] * timag + wimag[j - 1] * treal;

	}

 

    for (m = 2; m <= n; m *= 2)

    {

		for (k = 0; k < n; k += m)

        {

			for (j = 0; j < m / 2; j ++)

            {

				index1 = k + j;

                index2 = index1 + m / 2;

                t = n * j / m;

                treal = wreal[t] * xreal[index2] - wimag[t] * ximag[index2];

                timag = wreal[t] * ximag[index2] + wimag[t] * xreal[index2];

                ureal = xreal[index1];

                uimag = ximag[index1];

                xreal[index1] = ureal + treal;

                ximag[index1] = uimag + timag;

                xreal[index2] = ureal - treal;

                ximag[index2] = uimag - timag;

            }

        }

    }

}



void CFastFourier::IFFT(double* xreal, double* ximag, int n)

{

	double	wreal [N_ARRAY / 2], wimag [N_ARRAY / 2], treal, timag, ureal, uimag;

	double	arg;

    int		m, k, j, t, index1, index2;

     

    bitrp (xreal, ximag, n);

    

    arg			= 2 * PI / n;

    treal		= cos(arg);

    timag		= sin(arg);

    wreal[0]	= 1.0;

    wimag[0]	= 0.0;

    

	for (j = 1; j < n / 2; j ++)

	{

		wreal[j] = wreal[j - 1] * treal - wimag[j - 1] * timag;

        wimag[j] = wreal[j - 1] * timag + wimag[j - 1] * treal;

    }

 

    for (m = 2; m <= n; m *= 2)

	{

        for (k = 0; k < n; k += m)

		{

			for (j = 0; j < m / 2; j ++)

            {

				index1 = k + j;

                index2 = index1 + m / 2;

                t = n * j / m;

                treal = wreal[t] * xreal[index2] - wimag[t] * ximag[index2];

                timag = wreal[t] * ximag[index2] + wimag[t] * xreal[index2];

                ureal = xreal[index1];

                uimag = ximag[index1];

                xreal[index1] = ureal + treal;

                ximag[index1] = uimag + timag;

                xreal[index2] = ureal - treal;

                ximag[index2] = uimag - timag;

            }

        }

	}

 

	for (j=0; j < n; j ++)

    {

		xreal[j] /= n;

        ximag[j] /= n;

	}

}



void CFastFourier::roundoff(double* zreal, int n)

{

	int i;

	

	for(i=0;i<n;i++)

		zreal[i] = (double)((int)(zreal[i] + 0.5));

}



void CFastFourier::mularray(double* xreal, double* ximag, double* yreal, double* yimag, double* zreal, double* zimag, int n)

{

	int i;

	

	for(i=0;i<n;i++)

	{

		zreal[i] = 	xreal[i] * yreal[i] - ximag[i] * yimag[i];

		zimag[i] =	xreal[i] * yimag[i] + yreal[i] * ximag[i];

	}

}



void CFastFourier::fft_conv(double* xreal, double* ximag, double* yreal, double* yimag, double* zreal, double* zimag, int n)

{

	FFT(xreal, ximag, n);

	FFT(yreal, yimag, n);



	mularray(xreal, ximag, yreal, yimag, zreal, zimag, n);

			

	IFFT(zreal, zimag, n);

}
goodname 2009-05-27
  • 打赏
  • 举报
 回复
fft_ifft.h


#define N_ARRAY	1024

#define PI		3.1416



class CFastFourier

{

public:

	CFastFourier();

	virtual ~CFastFourier();



	void swap(double* a, double* b);

	void bitrp(double* xreal, double* ximag, int n);

	void FFT(double* xreal, double* ximag, int n);

	void IFFT(double* xreal, double* ximag, int n);

	void roundoff(double* zreal, int n);

	void mularray(double* xreal, double* ximag, double* yreal, double* yimag, double* zreal, double* zimag, int n);

	void fft_conv(double* xreal, double* ximag, double* yreal, double* yimag, double* zreal, double* zimag, int n);

};
我看你有戏 2009-05-27
  • 打赏
  • 举报
 回复
http://www.coolsou.net
抄写
http://www.qvodsou.com
ex_dijkstra 2009-05-27
  • 打赏
  • 举报
 回复
既然要置顶,赶快留名占位接分
满衣兄 2009-05-27
  • 打赏
  • 举报
 回复
好帖子!申请斑竹置顶!
Sou2012 2009-05-27
  • 打赏
  • 举报
 回复
MARK!!
acrobatyuer 2009-05-27
  • 打赏
  • 举报
 回复
不错。。。收藏了。。。
bandboy886 2009-05-26
  • 打赏
  • 举报
 回复
这也叫菜鸟，我无地自容了·
wwoo_1105 2009-05-26
  • 打赏
  • 举报
 回复
帮顶
满衣兄 2009-05-26
  • 打赏
  • 举报
 回复
[Quote=引用 16 楼 goodname 的回复:]
是不是调用一个函数就可以了呢。
[/Quote]
不是,我猜应该是这样:先对语音数据进行FFT得到xreal值和ximag值,xreal是需要处理的数据,ximag是中间值.然后对xreal中的值进行处理,然后利用ximag恢复xreal的值.
也不知道猜的对不对,郁闷,关键这个原理不明白,找了一圈也没找到.
我修改成这样:
float	xreal[N_ARRAY] = {0};

	char tmp[N_ARRAY] = {0};

	memcpy(tmp,dstBuf,len);

	for (int i=0;i<512;i++)

	{

		xreal[i] = (float)tmp[i];

		if (xreal[i]<20||xreal[i]>44100)

		{

			xreal[i]=0;

		}

	}

	float	ximag[N_ARRAY] = {0};

	p_myFourier->FFT(xreal, ximag, 512);

	p_myFourier->IFFT(xreal, ximag, 512);



	for (int k=0; k<len; k++)

	{

		dstBuf[k] = (char)xreal[k];

	}

	delete p_myFourier;

	p_myFourier = NULL;

声音平滑了很多,听起来也舒服了,可是音质变的很差,听对方说话就翁翁的,我晕啊.
goodname 2009-05-26
  • 打赏
  • 举报
 回复
http://www.chinavib.com/forum/viewthread.php?tid=69860
加载更多回复（16）
菜鸟裹裹快递查询接口调用
为什么80%的码农都做不了架构师？>>> ...
10. C函数的定义和调用
10. C函数的定义和调用
【菜鸟逆袭记】之初识函数
哥们哥们，函数函数，你了解吗？ 菜鸟逆袭记的函数看过了吗？ 没看过的来看看吧
函数调用不添加括号代表什么？
函数调用不添加括号代表什么？
C语言菜鸟入门·函数
/ 函数体表示函数返回值的类型，可以是任意合法的数据类型，如果函数不返回数值则用void表示。是函数的名字，用来标识函数。是函数的参数列表，如果函数不需要参数，则在括号内留空。每个参数由参数类型和参数名组成，多个参数之间用逗号分隔。函数体包含了实际的操作逻辑，它由大括号括起来。这个函数名为add，接受两个整型参数a和b，返回值类型为整型。函数体内的操作是将参数a和b相加，并返回结果。综上我们分析出：在 C 语言中，函数由一个函数头和一个函数主体组成。一个函数可以返回一个值。
C++ 语言

65,211

社区成员

250,514

社区内容

发帖
与我相关
我的任务
社区描述
C++ 语言相关问题讨论，技术干货分享，前沿动态等
c++ 技术论坛（原bbs）
社区管理员
  • C++ 语言社区
  • encoderlee
  • paschen
加入社区
  • 近7日
  • 近30日
  • 至今

加载中

查看更多榜单
社区公告
  1. 请不要发布与C++技术无关的贴子
  2. 请不要发布与技术无关的招聘、广告的帖子
  3. 请尽可能的描述清楚你的问题，如果涉及到代码请尽可能的格式化一下

试试用AI创作助手写篇文章吧

+ 用AI写文章