pydub追加对幕后行为的澄清

Question

我一直在使用pydub将短的声音文件连接成一个更大的声音文件。其基本代码如下所示：

def permuPhrase(iterations, joins): # Builds a single phrase and does various permutations of it
sampleSet = entryMatcher()
sampleSet.inputVars()
sampleSet.match()
concat = 0
if len(sampleSet.results) != 0:
    for x in range(iterations):
        for i in range(joins):
            rand = rn.randint(0, len(sampleSet.results)- 1)
            choice = str(sampleSet[rand])
            concat += (AudioSegment.from_wav(source+choice+affix))
        numIter = str(x) # convert parent for loop to string for naming .wav files.
        concat.export(newDir+numIter+affix, format="wav") # export
else:
    print("No samples matched")

我的问题是这个。在API中，它指出默认情况下有一个100ms的交叉淡入。但是，下面给出的示例表明，如果使用+运算符连接样本，则不使用交叉淡入。我想知道是否有人能澄清这一点？我链接了API，因为复制示例不可读。它在AudioSegment（…）.append（）下。在

AudioSegment(…).append()

Returns a new AudioSegment, created by appending another AudioSegment to this one (i.e., adding it to the end), Optionally using a crossfade. AudioSegment(…).append() is used internally when adding AudioSegment objects together with the + operator.

By default a 100ms (0.1 second) crossfade is used to eliminate pops and crackles.

from pydub import AudioSegment
sound1 = AudioSegment.from_file("sound1.wav")
sound2 =AudioSegment.from_file("sound2.wav")

# default 100 ms crossfade
combined = sound1.append(sound2)

# 5000 ms crossfade
combined_with_5_sec_crossfade = sound1.append(sound2, crossfade=5000)

# no crossfade
no_crossfade1 = sound1.append(sound2, crossfade=0)

# no crossfade
no_crossfade2 = sound1 + sound2

Supported keyword arguments:

• crossfade | example: 3000 | default: 100 (entire duration of AudioSegment) When specified, method returns number of frames in X milliseconds of the AudioSegment

Answer 1

我可以确认使用+运算符的连接不会应用任何交叉淡入（实际上calls the append method with crossfade=0）

设计决定的原因是允许使用sum（）和reduce（）以及其他类似的方法将一堆块放回一起，而不改变总持续时间（由于交叉渐变重叠）