pythonpyaudio

How to split an audio file to have chunks that are less than a certain dimension in python?

I need to divide an audio file to have chunks that are less than 25mb.

I would like to not have to save the file on the disk.

This is the code I have for now, but it is not working as expected, as it splits the audio in chunks of around 2mb

def audio_splitter(audio_file)
    audio = AudioSegment.from_file(audio_file)

    # Set the chunk size and overlap
    target_chunk_size = 20 * 1024 * 1024  # Target chunk size in bytes (20 MB)
    # Overlap in milliseconds (10 seconds)
    overlap_duration = 10 * 1000
    # Estimate the number of bytes per millisecond in the audio
    bytes_per_ms = len(audio.raw_data) / len(audio)
    # Calculate duration of each chunk in milliseconds
    chunk_duration = int(target_chunk_size / bytes_per_ms)

    chunks = []
    start = 0
    while start < len(audio):
        end = start + chunk_duration
        chunk = audio[start:end]
        chunks.append(chunk)
        start += chunk_duration - overlap_duration

    for i, chunk in enumerate(chunks):
        chunk.export(f"chunk_{i + 1}.mp3", format="mp3")

I think there is a problem with len(audio.raw_data) as it seems not to return the correct byte size.

Is there a better method altogheter to approach this problem?

Solution

  • You can use bytes.IO estimation In my test case I used 1/2 mb limit and files were all exactly 512kb,512kb,426kb,71.1kb

    from pydub import AudioSegment
import io
import sys
import os



def audio_splitter(audio_file):
    audio = AudioSegment.from_file(audio_file)

    test = audio[0:len(audio)]
    test_io = io.BytesIO()
    test.export(test_io, format="mp3")
    test_size = sys.getsizeof(test_io)


    # Set the chunk size and overlap
    target_chunk_size = 20 * 1024 * 1024  # Target chunk size in bytes (20 MB)
    # Overlap in milliseconds (10 seconds)
    overlap_duration = 10 * 1000
    # Estimate the number of bytes per millisecond in the audio
    bytes_per_ms = test_size/len(audio) # Estimation
    # Calculate duration of each chunk in milliseconds
    chunk_duration = int(target_chunk_size / bytes_per_ms)

    chunks = []
    start = 0
    while start < len(audio):
        end = start + chunk_duration
        chunk = audio[start:end]
        chunks.append(chunk)
        start += chunk_duration - overlap_duration

    for i, chunk in enumerate(chunks):
        chunk.export(f"chunk_{i + 1}.mp3", format="mp3")

if __name__ == "__main__":
    audio_splitter(*sys.argv[1:])