pydub 可以设置 maximum/minimum 音量吗？

Question

如题，我可以给maximum/minimum音量设置一个值，即输出的音频文件不会太大声或太小声吗？（不是正常化，我只是想把特定的音量调到正常，如下图。）

Answer 1

Loudness 有点复杂 - 一个简单的解决方案是使用一种更简单的方法（如 dBFS）进行测量，并将所有音频的增益设置为匹配。

sounds = [audio_segment1, audio_segment2, audio_segment3, audio_segment4]

def set_loudness(sound, target_dBFS):
    loudness_difference = target_dBFS - sound.dBFS
    return sound.apply_gain(loudness_difference)

# -20dBFS is relatively quiet, but very likely to be enough headroom    
same_loudness_sounds = [
    set_loudness(sound, target_dBFS=-20)
    for sound in sounds
]

一个复杂的因素是您的某些声音可能有较长的静音部分，或者甚至只是非常安静的部分。这会拉低平均值，您可能必须编写更复杂的响度测量。同样，一个简单的方法，您可以将声音切成较短的片段，并简单地使用最响亮的片段，假设您的整个声音有 15 分钟长，我们可以将 1 分钟片段：

from pydub.utils import make_chunks

def get_loudness(sound, slice_size=60*1000):
    return max(chunk.dBFS for chunk in make_chunks(sound, slice_size))


# ...and replace set_loudness() in above example with…
def set_loudness(sound, target_dBFS):
    loudness_difference = target_dBFS - get_loudness(sound)
    return sound.apply_gain(loudness_difference)

Answer 2

这就是我所做的，对我来说效果很好。缺点是 sample_rate 太小性能不好。

from pydub import AudioSegment
from pydub.utils import make_chunks

def match_target_amplitude(sound, target_dBFS):
    change_in_dBFS = target_dBFS - sound.dBFS
    return sound.apply_gain(change_in_dBFS)

def sound_slice_normalize(sound, sample_rate, target_dBFS):
    def max_min_volume(min, max):
        for chunk in make_chunks(sound, sample_rate):
            if chunk.dBFS < min:
                yield match_target_amplitude(chunk, min)
            elif chunk.dBFS > max:
                yield match_target_amplitude(chunk, max)
            else:
                yield chunk

    return reduce(lambda x, y: x + y, max_min_volume(target_dBFS[0], target_dBFS[1]))

sound = AudioSegment.from_mp3("vanilla_sky.mp3")
normalized_db = min_normalized_db, max_normalized_db = [-32.0, -18.0]
sample_rate = 1000
normalized_sound = sound_slice_normalize(sound, sample_rate, normalized_db)

pydub 可以设置 maximum/minimum 音量吗？

Can pydub set the maximum/minimum volume?

python

audio

volume

limit

pydub