slice_audio.py

import os
import argparse
from tqdm import tqdm

START = 00
FOLDER = "chunks"
DEBUG = True

def seconds_to_hms(seconds):
    """
    Convert seconds to hours, minutes, seconds format.
    
    Args:
        seconds (int): Total number of seconds to convert
        
    Returns:
        tuple: A tuple containing (hours, minutes, seconds)
        
    Example:
        >>> seconds_to_hms(3665)
        (1, 1, 5)  # 1 hour, 1 minute, 5 seconds
    """
    hour = 00
    minute = 00
    second = seconds

    while second >= 60:
        minute += 1
        second -= 60
        while minute >= 60:
            hour += 1
            minute -= 60

    return hour, minute, second

def hms_to_seconds(hour, minute, second):
    """
    Convert hours, minutes, seconds to total seconds.
    
    Args:
        hour (int): Number of hours
        minute (int): Number of minutes
        second (int): Number of seconds
        
    Returns:
        int: Total number of seconds
        
    Example:
        >>> hms_to_seconds(1, 1, 5)
        3665  # 1 hour + 1 minute + 5 seconds in seconds
    """
    return hour*3600 + minute*60 + second

def slice_audio(input_audio_path, output_folder, chunks_seconds, chunk_overlap_seconds):
    """
    Slice audio into chunks with specified duration and overlap.
    
    This function takes an audio file and splits it into smaller chunks with a specified
    duration and overlap between chunks. It uses ffmpeg for the actual audio processing.
    
    Args:
        input_audio_path (str): Path to the input audio file
        output_folder (str): Directory where the chunks will be saved
        chunks_seconds (int): Duration of each chunk in seconds
        chunk_overlap_seconds (int): Amount of overlap between consecutive chunks in seconds
        
    Returns:
        None: Creates audio chunks in the specified output folder and generates
              a text file listing all chunk files
        
    Raises:
        ValueError: If chunk_overlap_seconds is greater than or equal to chunks_seconds
        
    Example:
        >>> slice_audio("input.mp3", "chunks", 30, 5)
        # Creates chunks of 30 seconds with 5 seconds overlap
    """
    _, filename = os.path.split(input_audio_path)
    name, extension = os.path.splitext(filename)

    # Get audio duration in seconds
    duration = float(os.popen(f'ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 {input_audio_path}').read())
    hour, minute, second = seconds_to_hms(int(duration))
    print(f"\tDuration ({duration} seconds): {hour:02d}:{minute:02d}:{second:02d}")

    # Calculate effective chunk duration considering overlap
    effective_chunk = chunks_seconds - chunk_overlap_seconds
    
    # Calculate number of chunks needed
    if effective_chunk > 0:
        num_chunks = -(-int(duration - chunk_overlap_seconds) // effective_chunk)  # Ceiling division
    else:
        raise ValueError("Overlap duration must be less than chunk duration")

    # Slice audio into chunks with overlap
    output_files = []
    progress_bar = tqdm(total=num_chunks, desc="Slice audio into chunks progress")
    
    for chunk in range(num_chunks):
        # Calculate start and end times for this chunk
        start_time = chunk * effective_chunk
        end_time = min(start_time + chunks_seconds, duration)
        
        # Convert times to HH:MM:SS format
        hour_start, minute_start, second_start = seconds_to_hms(start_time)
        
        # Calculate chunk duration
        chunk_duration = end_time - start_time
        hour_duration, minute_duration, second_duration = seconds_to_hms(chunk_duration)
        
        # Generate output filename
        output = f"{output_folder}/{name}_chunk{chunk:003d}{extension}"

        if DEBUG:
            if os.path.exists(output):
                output_files.append(output)
                progress_bar.update(1)
                continue
        
        # Build ffmpeg command with -y flag to overwrite without asking
        if chunk == num_chunks - 1:  # Last chunk
            command = f'ffmpeg -y -i {input_audio_path} -ss {hour_start:02d}:{minute_start:02d}:{second_start:02d} -loglevel error {output}'
        else:
            command = f'ffmpeg -y -i {input_audio_path} -ss {hour_start:02d}:{minute_start:02d}:{second_start:02d} -t {hour_duration:02d}:{minute_duration:02d}:{second_duration:02d} -loglevel error {output}'
        
        # Execute command
        os.system(command)
        output_files.append(output)
        progress_bar.update(1)

    progress_bar.close()

    # Write output files to a txt file (with overwrite)
    with open(f"{output_folder}/output_files.txt", "w") as f:
        for output_file in output_files:
            f.write(f"{output_file}\n")