Bash script to trip mp3s to one hour in length and convert to AAC

trim_mp3s.sh

#!/bin/bash

# Set the directory where your MP3 files are located
input_dir="."

# Set the desired output bitrate (in bits per second)
output_bitrate="192k"  # Adjust this value as needed

# Loop through each MP3 file in the directory
for file in "$input_dir"/*.mp3; do
    # Extract the filename without extension
    filename=$(basename -- "$file")
    filename_no_ext="${filename%.*}"

    # Output filename for the extended AAC file
    output_file="${input_dir}/${filename_no_ext}_1_hour.aac"

    # Use FFmpeg to extend the MP3 file to one hour with specified output quality and preserve metadata
    ffmpeg -i "$file" -t 3600 -c:a aac_at -b:a "$output_bitrate" "$output_file"
done

Courtesy of ChatGPT with some tweaking by yours truly. I used this to make shorter versions of some nature recordings I purchased from https://relaxingnaturevideos.gumroad.com.