Split audio extracted with ytdlp using youtube timestamps saved as csv

ffmpeg_split_audio.sh

#!/bin/bash

# Function to sanitize a string by removing invalid characters
sanitize_filename() {
  local filename="$1"
  # Replace invalid characters with underscore
  filename="${filename//[^a-zA-Z0-9_.-]/_}"
  echo "$filename"
}

# Function to check if a file exists and prompt for overwrite if necessary
check_file_exists() {
  local filename="$1"
  local always_override="$2"

  if [[ -e "$filename" ]]; then
    if [[ "$always_override" == "true" ]]; then
      rm "$filename"
    else
      read -p "File '$filename' already exists. Do you want to override it? (y/n): " overwrite
      if [[ "$overwrite" == "y" || "$overwrite" == "Y" ]]; then
        rm "$filename"
      else
        echo "Skipping file '$filename'."
        return 1
      fi
    fi
  fi
  return 0
}

# Check if input files are provided
if [[ "$#" -lt 2 ]]; then
  echo "Usage: $0 <input_audio_file> <input_csv_file> [--override]"
  exit 1
fi

# Input audio file and CSV file
audio_file="$1"
csv_file="$2"

# Check if --override flag is provided
always_override="false"
if [[ "$#" -eq 3 && "$3" == "--override" ]]; then
  always_override="true"
fi

# Check if input audio file exists
if [[ ! -e "$audio_file" ]]; then
  echo "Error: Input audio file '$audio_file' does not exist."
  exit 1
fi

# Check if input audio file is a valid audio file
file_type=$(file -b --mime-type "$audio_file")
if [[ ! $file_type =~ ^audio/ ]]; then
  echo "Error: Input audio file '$audio_file' is not a valid audio file."
  exit 1
fi

# Check if input CSV file exists
if [[ ! -e "$csv_file" ]]; then
  echo "Error: Input CSV file '$csv_file' does not exist."
  exit 1
fi

# Check if input CSV file is a valid CSV file
file_type=$(file -b --mime-type "$csv_file")
if [[ $file_type != "text/csv" ]]; then
  echo "Error: Input CSV file '$csv_file' is not a valid CSV file."
  exit 1
fi

# Counter for prefixing title with a number
counter=1

# Audio file extension
output_extension="${audio_file##*.}"

# Read CSV file into array
while IFS=',' read -r line || [[ -n "$line" ]]; do
  # Add line to csv_lines array
  csv_lines+=("$line")
done < "$csv_file"


# Iterate over the csv_lines array
for ((i=0; i<${#csv_lines[@]}; i++)); do
  # Get current line from array
  line="${csv_lines[$i]}"

  # Split the line into start timestamp and title
  start_timestamp=$(echo "$line" | cut -d ',' -f 1)
  title=$(echo "$line" | cut -d ',' -f 2)

  # Sanitize the title to use as a filename
  sanitized_title=$(sanitize_filename "$title")

  # Generate the output file name with counter prefix
  output_file=$(printf "%02d_%s.%s" "$counter" "$sanitized_title" "$output_extension")

  # Check if output file already exists
  if ! check_file_exists "$output_file" "false"; then
    # Increment the counter
    ((counter++))
    continue
  fi

  # Check if current line is the last line in the array
  if (( i == ${#csv_lines[@]}-1 )); then
    # This is the last line, use end of audio file as end timestamp
    end_timestamp=$(ffmpeg -i "$audio_file" 2>&1 | grep Duration | awk '{print $2}' | tr -d ,)
  else
    # Get next line from array and update the counter
    ((counter++))
    line="${csv_lines[$((i+1))]}"
    # Split the next line into start timestamp and title
    end_timestamp=$(echo "$line" | cut -d ',' -f 1)
  fi


  # Extract the audio segment using ffmpeg
  echo ffmpeg -i "$audio_file" -ss  "$start_timestamp" -to "$end_timestamp" -c copy "$output_file"
  ffmpeg -i "$audio_file" -ss  "$start_timestamp" -to "$end_timestamp" -c copy "$output_file"
  echo "Segment $output_file created successfully."

done