如何用python实现音乐的频谱显示

Python044

如何用python实现音乐的频谱显示,第1张

用pymedia可以很容易的实现：

import pymedia.audio.acodec as acodec

sName='YOUR FILENAME'

dec= acodec.Decoder( str.split( sName, '.' )[ -1 ].lower() )

f= open( sName, 'rb' )

s= f.read( 8192 )

r= dec.decode( s )

import pymedia.audio.sound as sound

snd= sound.Output( r.sample_rate, r.channels, sound.AFMT_S16_LE )

while len( s )>0:

if r: snd.play( r.data )

s= f.read( 512 )

r= dec.decode( s )

import time

while snd.isPlaying(): time.sleep( .05 )

1.读取wav文件

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

import wave

import pylab as pl

import numpy as np

# 打开WAV文档

f = wave.open(r"c:\WINDOWS\Media\ding.wav", "rb")

# 读取格式信息

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

params = f.getparams()

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

# 读取波形数据

str_data = f.readframes(nframes)

f.close()

#将波形数据转换为数组

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

wave_data.shape = -1, 2

wave_data = wave_data.T

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

# 绘制波形

pl.subplot(211)

pl.plot(time, wave_data[0])

pl.subplot(212)

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

pl.xlabel("time (seconds)")

pl.show()

2.观察信号频谱

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

import numpy as np

import pylab as pl

sampling_rate = 8000

fft_size = 512

t = np.arange(0, 1.0, 1.0/sampling_rate)

x = np.sin(2*np.pi*156.25*t) + 2*np.sin(2*np.pi*234.375*t)

xs = x[:fft_size]

xf = np.fft.rfft(xs)/fft_size

freqs = np.linspace(0, sampling_rate/2, fft_size/2+1)

xfp = 20*np.log10(np.clip(np.abs(xf), 1e-20, 1e100))

pl.figure(figsize=(8,4))

pl.subplot(211)

pl.plot(t[:fft_size], xs)

pl.xlabel(u"时间(秒)")

pl.title(u"156.25Hz和234.375Hz的波形和频谱")

pl.subplot(212)

pl.plot(freqs, xfp)

pl.xlabel(u"频率(Hz)")

pl.subplots_adjust(hspace=0.4)

pl.show()