持续时间等于帧数除以帧率(每秒帧数)：
import wave
import contextlib
fname = ‘/tmp/test.wav’
with contextlib.closing(wave.open(fname,’r’)) as f:
frames = f.getnframes()
rate = f.getframerate()
duration = frames / float(rate)
print(duration)
关于@edwards的评论，这里有一些代码来产生一个2声道的波形文件：
import math
import wave
import struct
FILENAME = “/tmp/test.wav”
freq = 440.0
data_size = 40000
frate = 1000.0
amp = 64000.0
nchannels = 2
sampwidth = 2
framerate = int(frate)
nframes = data_size
comptype = “NONE”
compname = “not compressed”
data = [(math.sin(2 * math.pi * freq * (x / frate)),
math.cos(2 * math.pi * freq * (x / frate))) for x in range(data_size)]
try:
wav_file = wave.open(FILENAME, ‘w’)
wav_file.setparams(
(nchannels, sampwidth, framerate, nframes, comptype, compname))
for values in data:
for v in values:
wav_file.writeframes(struct.pack(‘h’, int(v * amp / 2)))
finally:
wav_file.close()
如果您在音频播放器中播放结果文件，您会发现持续时间为40秒。如果您运行上面的代码，还会计算持续时间为40秒。所以我相信帧的数量不受频道数量的影响，上面的公式是正确的。