对于语音信号的音高分析,可以使用基频提取技术。基频是指一个声音周期的重复率,也就是一个声音波形中最长的周期。
通常情况下,人的声音基频范围是85Hz到255Hz。根据语音信号的基频可以推断出其音高。
C++中可以使用数字信号处理库或语音处理库,比如MATLAB、Praat、YIN算法等等来进行音高分析。以下是使用YIN算法进行音高分析的示例代码:
#include <cmath>
#include <algorithm>#define SAMPLE_RATE 44100
#define BUFFER_SIZE 2048
#define MIN_FREQ 80
#define MAX_FREQ 1000double YinPitch(float* buffer, int bufferSize)
{double pitch = -1;double yin[BUFFER_SIZE/2];for (int tau = 0; tau < bufferSize/2; tau++){yin[tau] = 0;for (int j = 0; j < bufferSize/2; j++){double diff = buffer[j] - buffer[j+tau];yin[tau] += diff * diff;}yin[tau] /= bufferSize/2;}for (int tau = 1; tau < bufferSize/2; tau++){if (yin[tau] < 0.0001){continue;}int period = tau;while ((period < bufferSize/2) && (yin[period] < yin[period-1])){period++;}if (period >= bufferSize/2){break;}double freq = SAMPLE_RATE / period;if ((freq >= MIN_FREQ) && (freq <= MAX_FREQ)){if (pitch < 0){pitch = freq;}else{pitch = 0.5 * pitch + 0.5 * freq;}}}return pitch;
}
这段代码使用了YIN算法来计算语音信号的基频,得出的结果即为音高。
其中,缓冲区大小为2048,最小基频为80Hz,最大基频为1000Hz。通常情况下,音高在85Hz到255Hz之间,因此可以根据实际情况修改最小和最大基频值。