<p>这是我从Nathan Whitehead编写的SWMixer模块中选择的:</p>
<pre><code>import numpy
def resample(smp, scale=1.0):
"""Resample a sound to be a different length
Sample must be mono. May take some time for longer sounds
sampled at 44100 Hz.
Keyword arguments:
scale - scale factor for length of sound (2.0 means double length)
"""
# f*ing cool, numpy can do this with one command
# calculate new length of sample
n = round(len(smp) * scale)
# use linear interpolation
# endpoint keyword means than linspace doesn't go all the way to 1.0
# If it did, there are some off-by-one errors
# e.g. scale=2.0, [1,2,3] should go to [1,1.5,2,2.5,3,3]
# but with endpoint=True, we get [1,1.4,1.8,2.2,2.6,3]
# Both are OK, but since resampling will often involve
# exact ratios (i.e. for 44100 to 22050 or vice versa)
# using endpoint=False gets less noise in the resampled sound
return numpy.interp(
numpy.linspace(0.0, 1.0, n, endpoint=False), # where to interpret
numpy.linspace(0.0, 1.0, len(smp), endpoint=False), # known positions
smp, # known data points
)
</code></pre>
<p>所以,如果你用的是scipy,那意味着你也有numpy。如果scipy不是“必须的”,那么使用这个,它可以完美地工作。</p>