python手记(45)

python 声音编辑，减少音量

 

#!/usr/bin/env python  

# -*- coding: utf-8 -*-

#http://blog.csdn.net/myhaspl  

#code:[email protected] 

import wave

import pylab as pl

import numpy as np



print 'http://blog.csdn.net/myhaspl'  

print '[email protected]'  

print  

  

print 'working...' 



def wavechange(x,dwmax,dwmin):

    if x!=0:

        if abs(x)<dwmax and abs(x)>dwmin:

            x=x*0.5

        else:

            x=x*0.2

    return x





# 打开WAV文档

f = wave.open(r"speak.wav", "rb")

fo = wave.open(r"jg.wav", "wb")

# 读取波形数据

# (nchannels, sampwidth, framerate, nframes, comptype, compname)

params = f.getparams()

nchannels, sampwidth, framerate, nframes = params[:4]

print "read wav data...."

str_data = f.readframes(nframes)



#将波形数据转换为数组，并更改

print "update wav data...."

wave_data = np.fromstring(str_data, dtype=np.short)

params = f.getparams()

nchannels, sampwidth, framerate, nframes = params[:4]

str_data = f.readframes(nframes)



#降低声音

change_dwmax=wave_data.max()/100*1

change_dwmin=wave_data.max()/100*0.5

wave_change = np.frompyfunc(wavechange,3,1)

new_wave_data =wave_change(wave_data,change_dwmax,change_dwmin)

new_wave_data =new_wave_data.astype(wave_data.dtype)

new_str_data=new_wave_data.tostring()

#写波形数据参数

print "save new wav files...."

fo.setnchannels(nchannels)

fo.setframerate(framerate)

fo.setsampwidth(sampwidth)

fo.writeframes(new_str_data)





# 绘制波形

wave_data.shape = -1, 2

wave_data = wave_data.T

time = np.arange(0, nframes) * (1.0 / framerate)

pl.subplot(221)

pl.plot(time, wave_data[0])

pl.subplot(222)

pl.plot(time, wave_data[1], c="g")

pl.xlabel("time (seconds)")

pl.show()



# 绘制波形

new_wave_data.shape = -1, 2

new_wave_data =new_wave_data.T

new_time = np.arange(0, nframes) * (1.0 / framerate)

pl.subplot(223)

pl.plot(new_time,new_wave_data[0])

pl.subplot(224)

pl.plot(new_time, new_wave_data[1], c="g")

pl.xlabel("time (seconds)")

pl.show()