#!/usr/bin/env bash # Description: # - Finds audio and video files with specified extensions up to a max depth of 8. # - Uses ffprobe to measure their durations. # - Creates a playlist starting at a random location within the total runtime. # - Stores durations and file paths in a dotfile for faster subsequent runs. # - Prompts the user whether to use the cached data or regenerate it. # - Uses an EDL file to specify the starting offset for the first file. # Usage: rand_media_pl.sh [DIR] # Version: 0.1.0 # Dependencies: Bash 4, ffprobe, mpv, bc, shuf, GNU Parallel yell() { echo "$0: $*" >&2; } # Print script path and all args to stderr die() { yell "$*"; exit 111; } # Same as yell() but exits with code 111 must() { "$@" || die "cannot $*"; } # Runs args as command, reports args if command fails # Configurable variables SEARCH_DIR="${1:-.}" # Default to current directory if no argument is provided MAX_DEPTH=8; EXTENSIONS=("*.flac" "*.mp3" "*.opus" "*.m4a" "*.m4b" "*.mp4" "*.mkv" "*.webm"); CACHE_FILE=".playlist_cache"; declare -gA file_durations; declare total_duration; # Function to prompt the user prompt_yes_no() { yell "STATUS: User input required."; local prompt_message="$1"; local user_input; while true; do read -rp "$prompt_message [y/n]: " user_input; case "$user_input" in [Yy]*) return 0 ;; [Nn]*) return 1 ;; *) echo "Please answer yes or no." ;; esac; done; }; # Function to find files with specified extensions find_media_files() { yell "STATUS: Finding media files."; local find_cmd=("find" "-L" "$SEARCH_DIR" "-maxdepth" "$MAX_DEPTH" "-type" "f" "("); for ext in "${EXTENSIONS[@]}"; do find_cmd+=("-iname" "$ext" "-o"); done; # Remove the last "-o" and add ")"; unset 'find_cmd[-1]'; find_cmd+=(")"); "${find_cmd[@]}"; }; # Function to generate the playlist cache generate_playlist_cache() { yell "Generating playlist cache. This may take a while..." # Initialize or empty the cache file : > "$CACHE_FILE"; # Truncate or create the cache file total_duration=0; while IFS= read -r file; do # Get the duration using ffprobe duration=$(ffprobe -v error -show_entries format=duration \ -of default=noprint_wrappers=1:nokey=1 "$file"); declare -p file duration 1>&2; # Debugging statement # Validate the duration if [[ -n "$duration" && "$duration" =~ ^[0-9]+(\.[0-9]+)?$ ]]; then # Append the file path and duration to the cache file printf "%s|%s\n" "$file" "$duration" >> "$CACHE_FILE"; total_duration=$(echo "$total_duration + $duration" | bc); else yell "WARNING: Invalid duration '$duration' for file '$file', skipping." 1>&2; fi; done < <(find_media_files | parallel readlink -f '{}' | sort -u; ); total_duration_s="$(printf "%.1f" "$total_duration"; )"; total_duration_h="$(echo "scale=1; $total_duration / 3600" | bc -l; )"; yell "Total duration of playlist: ${total_duration_s} seconds (${total_duration_h} hours)."; }; # Function to read the playlist cache read_playlist_cache() { # Input: file_durations associative array # total_duration scalar yell "STATUS: Reading playlist cache." total_duration=0 while IFS='|' read -r file duration; do declare -p file duration 1>&2 # Debugging statement # Validate the duration if [[ -n "$duration" && "$duration" =~ ^[0-9]+(\.[0-9]+)?$ ]]; then file_durations["$file"]="$duration" total_duration=$(echo "$total_duration + $duration" | bc) else yell "WARNING: Invalid duration '$duration' for file '$file', skipping." 1>&2 fi done < "$CACHE_FILE"; }; # Function to get byte count of file name prepend_path_bc() { # Desc: Prepends a file path with %[path bytecount]% # Usage: prepend_filename_bc [FILE] # Input: arg1 str file path # Output: stdout str %[int path length]%path # Example: 'foo.txt' yields '%7%foo.txt' # Depends: GNU Coreutils 8.32 (for 'wc') # BK-2020-03: yell(), die(), must() # Ref/Attrib: See “Syntax of mpv EDL files” https://github.com/mpv-player/mpv/blob/master/DOCS/edl-mpv.rst#syntax-of-mpv-edl-files fin="$1"; if [[ ! -f "$fin" ]]; then yell "WARNING:File does not exist:${fin}"; fi; bytecount="$(printf "%s" "$fin" | wc -c; )"; re='[0-9]'; if [[ ! "$bytecount" =~ $re ]]; then die "FATAL:Not an int:${bytecount}; $(declare -p fin bytecount)"; fi; printf "%%%s%%%s" "$bytecount" "$fin"; }; # Main script if [[ -f "$CACHE_FILE" ]]; then if prompt_yes_no "Playlist cache detected. Do you want to use it? (Faster)"; then read_playlist_cache; else generate_playlist_cache; read_playlist_cache; fi; else generate_playlist_cache; read_playlist_cache; fi; # Check if any files were found if [[ ${#file_durations[@]} -eq 0 ]]; then declare -p file_durations 1>&2; die "FATAL: No media files found."; fi; # Ensure total_duration is not empty if [[ -z "$total_duration" ]]; then die "FATAL: total_duration is empty."; fi; # Convert total_duration to an integer total_duration_int=$(printf "%.0f" "$total_duration"); # Check if total_duration_int is a valid integer if ! [[ "$total_duration_int" =~ ^[0-9]+$ ]]; then die "FATAL: total_duration_int is not a valid integer."; fi; # Generate a random integer between 0 and total_duration_int - 1 random_point=$(shuf -i 0-$((total_duration_int - 1)) -n1) yell "DEBUG: total_duration=$total_duration, total_duration_int=$total_duration_int, random_point=$random_point" 1>&2; # Get sorted list of files mapfile -t sorted_files < <(printf '%s\n' "${!file_durations[@]}" | sort; ); # Find the file and offset corresponding to the random starting point accumulated_duration=0; accumulated_duration_int=0; for idx in "${!sorted_files[@]}"; do file="${sorted_files[$idx]}"; duration="${file_durations["$file"]}"; declare -p idx file duration accumulated_duration 1>&2; # Debugging statement # Validate the duration if [[ -n "$duration" && "$duration" =~ ^[0-9]+(\.[0-9]+)?$ ]]; then new_accumulated_duration=$(echo "$accumulated_duration + $duration" | bc) # Convert accumulated durations to integers for comparison accumulated_duration_int=$(printf "%.0f" "$accumulated_duration") new_accumulated_duration_int=$(printf "%.0f" "$new_accumulated_duration") else yell "WARNING: Invalid duration '$duration' for file '$file', skipping." 1>&2 continue fi if (( random_point < new_accumulated_duration_int )); then offset=$(echo "$random_point - $accumulated_duration_int" | bc; ); yell "Starting playback from $offset seconds into file: $file"; # Create an EDL file edl_file=$(mktemp); yell "DEBUG:EDL file at:${edl_file}"; # debug echo "# mpv EDL v0" > "$edl_file"; # Add first file to start playback at random offset position file_bc="$(prepend_path_bc "$file")"; # See https://github.com/mpv-player/mpv/blob/master/DOCS/edl-mpv.rst#syntax-of-mpv-edl-files printf '%s,%s\n' "$file_bc" "$offset" >> "$edl_file"; # Append the rest of the files declare -p file offset idx sorted_files edl_file 1>&2; # debug for (( i=idx+1; i<${#sorted_files[@]}; i++ )); do next_file="${sorted_files[$i]}"; next_file_bc="$(prepend_path_bc "$next_file")"; yell "STATUS:Adding:$next_file"; printf '%s\n' "$next_file_bc" >> "$edl_file"; done; # Start playback using mpv mpv "$edl_file" || exit 1; # Securely delete the EDL file if [[ -n "$edl_file" && -f "$edl_file" ]]; then rm "$edl_file"; exit 0; else die "FATAL: edl_file is either unset or not a valid file, skipping deletion."; fi; fi; accumulated_duration="$new_accumulated_duration"; accumulated_duration_int="$new_accumulated_duration_int"; done; die "FATAL: Could not find file corresponding to random point.";