#?coding=utf-8
#?計算每一幀的MFCC系數

import?numpy
from?sigprocess?import?audio2frame
from?sigprocess?import?pre_emphasis
from?sigprocess?import?spectrum_power
from?scipy.fftpack?import?dct

#?首先，為了適配版本3.x，需要調整xrange的使用，因為對于版本2.x只能使用range，需要將xrange替換為range
try:
????xrange（1）
except:
????xrange?=?range


def?calcMFCC_delta_delta（signal?samplerate=16000?win_length=0.025?win_step=0.01?cep_num=13?filters_num=26
?????????????????????????NFFT=512?low_freq=0?high_freq=None?pre_emphasis_coeff=0.97?cep_lifter=22
?????????????????????????appendEnergy=True）:
????‘‘‘計算13個MFCC+13個一階微分系數+13個加速系數一共39個系數
????‘‘‘
????feat?=?calcMFCC（signal?samplerate?win_length?win_step?cep_num?filters_num?NFFT?low_freq?high_freq
????????????????????pre_emphasis_coeff?cep_lifter?appendEnergy）??#?首先獲取13個一般MFCC系數
????result1?=?derivate（feat）
????result2?=?derivate（result1）
????result3?=?numpy.concatenate（（feat?result1）?axis=1）
????result?=?numpy.concatenate（（result3?result2）?axis=1）
????return?result


def?calcMFCC_delta（signal?samplerate=16000?win_length=0.025?win_step=0.01?cep_num=13?filters_num=26?NFFT=512
???????????????????low_freq=0?high_freq=None?pre_emphasis_coeff=0.97?cep_lifter=22?appendEnergy=True）:
????‘‘‘計算13個MFCC+13個一階微分系數
????‘‘‘
????feat?=?calcMFCC（signal?samplerate?win_length?win_step?cep_num?filters_num?NFFT?low_freq?high_freq
????????????????????pre_emphasis_coeff?cep_lifter?appendEnergy）??#?首先獲取13個一般MFCC系數
????result?=?derivate（feat）??#?調用derivate函數
????result?=?numpy.concatenate（（feat?result）?axis=1）
????return?result


def?derivate（feat?big_theta=2?cep_num=13）:
????‘‘‘計算一階系數或者加速系數的一般變換公式
????參數說明:
????feat:MFCC數組或者一階系數數組
????big_theta:公式中的大theta，默認取2
????‘‘‘
????result?=?numpy.zeros（feat.shape）??#?結果
????denominator?=?0??#?分母
????for?theta?in?numpy.linspace（1?big_theta?big_theta）:
????????denominator?=?denominator?+?theta?**?2
????denominator?=?denominator?*?2??#?計算得到分母的值
????for?row?in?numpy.linspace（0?feat.shape[0]?-?1?feat.shape[0]）:
????????tmp?=?numpy.zeros（（cep_num））
????????numerator?=?numpy.zeros（（cep_num））??#?分子
????????for?t?in?numpy.linspace（1?cep_num?cep_num）:
????????????a?=?0
????????????b?=?0
????????????s?=?0
????????????for?theta?in?numpy.linspace（1?big_theta?big_theta）:
????????????????if?（t?+?theta）?>?cep_num:
????????????????????a?=?0
????????????????else:
????????????????????a?=?feat[int（row）][int（t?+?theta?-?1）]
????????????????if?（t?-?theta）?????????????????????b?=?0
????????????????else:
????????????????????b?=?feat[int（row）][int（t?-?theta?-?1）]
????????????????s?+=?theta?*?（a?-?b）
????????????numerator[int（t?-?1）]?=?s
????????tmp?=?numerator?*?1.0?/?denominator
????????result[int（row）]?=?tmp
????return?result


def?calcMFCC（signal?samplerate=16000?win_length=0.025?win_step=0.01?cep_num=13?filters_num=26?NFFT=512
?????????????low_freq=0?high_freq=None?pre_emphasis_coeff=0.97?cep_lifter=22?ap

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2020-12-09?19:36??MFCC\
?????文件????????9286??2020-11-10?16:19??MFCC\calcmfcc.py
?????文件?????????920??2020-11-19?17:08??MFCC\getWave.py
?????文件????????4526??2020-11-22?22:58??MFCC\MFCC_test.py
?????文件????????5878??2020-11-10?15:20??MFCC\sigprocess.py