用C语言编译一个谱减法降噪代码

谱减法降噪是一种常用的音频处理技术，可以通过消除噪声信号来提高音频的质量。以下是一个用C语言编写的谱减法降噪代码的示例：

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define PI 3.14159265358979323846

int main(int argc, char *argv[])
{
// 读取输入音频文件
FILE *inputFile = fopen(argv[1], "rb");
if (inputFile == NULL) {
printf("Error: Failed to open input file.\n");
return 1;
}

// 读取输出音频文件
FILE *outputFile = fopen(argv[2], "wb");
if (outputFile == NULL) {
printf("Error: Failed to open output file.\n");
return 1;
}

// 读取采样率和帧大小
int sampleRate = atoi(argv[3]);
int frameSize = atoi(argv[4]);

// 计算窗口函数
double window[frameSize];
for (int i = 0; i < frameSize; i++) {
window[i] = 0.54 - 0.46 * cos(2 * PI * i / (frameSize - 1));
}

// 读取音频数据并进行谱减法降噪
short buffer[frameSize];
while (fread(buffer, sizeof(short), frameSize, inputFile) == frameSize) {
// 计算FFT
double real[frameSize];
double imag[frameSize];
for (int i = 0; i < frameSize; i++) {
real[i] = buffer[i] * window[i];
imag[i] = 0;
}
fft(real, imag, frameSize);

// 计算噪声谱
double noise[frameSize];
for (int i = 0; i < frameSize; i++) {
noise[i] = sqrt(real[i] * real[i] + imag[i] * imag[i]);
}

// 计算信噪比
double snr = 0;
for (int i = 0; i < frameSize; i++) {
snr += noise[i] * noise[i];
}
snr /= frameSize;
snr = 10 * log10(snr);

// 进行谱减法降噪
for (int i = 0; i < frameSize; i++) {
double magnitude = sqrt(real[i] * real[i] + imag[i] * imag[i]);
double phase = atan2(imag[i], real[i]);
magnitude -= pow(10, snr / 20);
if (magnitude < 0) {
magnitude = 0;
}
real[i] = magnitude * cos(phase);
imag[i] = magnitude * sin(phase);
}

// 计算IFFT
ifft(real, imag, frameSize);

// 写入输出音频文件
for (int i = 0; i < frameSize; i++) {
buffer[i] = (short)real[i];
}
fwrite(buffer, sizeof(short), frameSize, outputFile);
}

// 关闭文件
fclose(inputFile);
fclose(outputFile);

return 0;
}

该代码使用了FFT和IFFT算法来进行频域处理，具体实现可以参考相关文献或开源库。