PyTorch Split a Wave to Some Clips with Same Length

In this tutorial, we will use an example to show you how to split a big wave file to some clips (small wave files) with same length. For example, there is a wave file with 500 seconds, we plan to split it to some small files, the duration of each small wave file is 5 senconds. How to do?

In pytorch, we can use the example code below:

import torch
import torchaudio

def load_audio(wave_file):
    wave_data, sr = torchaudio.load(wave_file)
    return wave_data, sr

def save_audio(wave_data, wave_file):
    torch.save(wave_data.clone(), wave_file, _use_new_zipfile_serialization=True)
def get_audio_clips(wave_file, min_sec = 5):
    wave_data, sr = load_audio(wave_file)

    min_clip_len = min_sec * sr

    wave_len = wave_data.shape[1]
    if wave_len < min_clip_len:
        repeat_num = min_clip_len // wave_len + 1
        wave_data = wave_data.repeat(1, repeat_num)
        wave_data = wave_data[:, :min_clip_len]
    else:
        clip_num = wave_len // min_clip_len + 1
        max_wave_len = clip_num * min_clip_len

        wave_data = wave_data.repeat(1, 2)
        wave_data = wave_data[:, :max_wave_len]

    feats = torch.split(wave_data, min_clip_len, dim = 1)
    return feats

We can use this code as follows:

wave_file = "music-jamendo-0039.wav"
feats = get_audio_clips(wave_file)
print(len(feats))
for feat in feats:
    print(feat.shape)

In this code, we will split music-jamendo-0039.wav to some 5 seconds small files. Run this code, we will see:

65
torch.Size([1, 80000])
torch.Size([1, 80000])
torch.Size([1, 80000])
torch.Size([1, 80000])
torch.Size([1, 80000])
torch.Size([1, 80000])
torch.Size([1, 80000])

To understand torch.split() and torchaudio.load(), you can see:

Understand torch.split(): Split Tensor into Chunks – PyTorch Tutorial

Understand torchaudio.load(): Read Audio with Examples – TorchAudio Tutorial