user/rand_media_pl.sh

   1 #!/usr/bin/env bash
   2 # Desc
   3 #   - Finds audio and video files with specified extensions up to a max depth of 8.
   4 #   - Uses ffprobe to measure their durations.
   5 #   - Creates a playlist starting at a random location within the total runtime.
   6 #   - Stores durations and file paths in a dotfile for faster subsequent runs.
   7 #   - Prompts the user whether to use the cached data or regenerate it.
   8 # Usage: rand_media_pl.sh [DIR]
   9 # Version: 0.0.1
  10 # Dependencies: Bash 4, ffprobe, mpv
  11
  12 yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
  13 die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
  14 must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
  15
  16 # Configurable variables
  17 SEARCH_DIR="$1";
  18 MAX_DEPTH=8;
  19 EXTENSIONS=("*.flac" "*.mp3" "*.opus" "*.m4a" "*.m4b" "*.mp4" "*.mkv" "*.webm");
  20 CACHE_FILE=".playlist_cache";
  21
  22 declare -gA file_durations;
  23 declare total_duration;
  24
  25 # Function to prompt the user
  26 prompt_yes_no() {
  27     yell "STATUS:User input required.";
  28     local prompt_message="$1"
  29     local user_input
  30     while true; do
  31         read -rp "$prompt_message [y/n]: " user_input
  32         case "$user_input" in
  33             [Yy]*) return 0 ;;
  34             [Nn]*) return 1 ;;
  35             *) echo "Please answer yes or no." ;;
  36         esac;
  37     done;
  38 };
  39
  40 # Function to find files with specified extensions
  41 find_media_files() {
  42     yell "STATUS:Finding media files.";
  43     local find_cmd=("find" "-L" "$SEARCH_DIR" "-maxdepth" "$MAX_DEPTH" "-type" "f" "(");
  44     #declare -p find_cmd 1>&2; # debug
  45     for ext in "${EXTENSIONS[@]}"; do
  46         find_cmd+=("-iname" "$ext" "-o");
  47         #declare -p find_cmd 1>&2; # debug
  48     done;
  49     # Remove the last "-o" and add ")"
  50     unset 'find_cmd[-1]';
  51     find_cmd+=(")");
  52     "${find_cmd[@]}";
  53 };
  54
  55 # Function to generate the playlist cache
  56 generate_playlist_cache() {
  57     yell "Generating playlist cache. This may take a while..."
  58     # Initialize or empty the cache file
  59     if [[ ! -f "$CACHE_FILE" ]]; then
  60         touch "$CACHE_FILE";
  61     else
  62         rm "$CACHE_FILE";
  63     fi;
  64
  65     total_duration=0
  66     while IFS= read -r file; do
  67         # Get the duration using ffprobe
  68         duration=$(ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 "$file")
  69         if [[ -n "$duration" ]]; then
  70             # Append the file path and duration to the cache file
  71             printf "%s|%s\n" "$file" "$duration" >> "$CACHE_FILE";
  72             total_duration=$(echo "$total_duration + $duration" | bc);
  73         fi;
  74     done < <(find_media_files | sort);
  75     total_duration_s="$(echo "scale=1; ${total_duration} / 1" | bc -l)";
  76     total_duration_h="$(echo "scale=1; ${total_duration} / 3600" | bc -l)";
  77
  78     yell "Total duration of playlist: ${total_duration_s} seconds. (${total_duration_h} hours.)";
  79 };
  80
  81 # Function to read the playlist cache
  82 read_playlist_cache() {
  83     # Input: file_durations  assoc. array
  84     #        total_duration  array
  85     yell "STATUS:Reading playlist cache.";
  86
  87     total_duration=0
  88     while IFS='|' read -r file duration; do
  89         file_durations["$file"]="$duration"
  90         total_duration=$(echo "$total_duration + $duration" | bc)
  91     done < "$CACHE_FILE"
  92 };
  93
  94 # Main script
  95 if [[ -f "$CACHE_FILE" ]]; then
  96     if prompt_yes_no "Playlist cache detected. Do you want to use it? (Faster)"; then
  97         read_playlist_cache;
  98     else
  99         generate_playlist_cache;
 100         read_playlist_cache;
 101     fi;
 102 else
 103     generate_playlist_cache;
 104     read_playlist_cache;
 105 fi;
 106
 107 # Check if any files were found
 108 if [[ ${#file_durations[@]} -eq 0 ]]; then
 109     declare -p file_durations 1>&2;
 110     die "FATAL:No media files found.";
 111 fi
 112
 113 # Get sorted list of files
 114 mapfile -t sorted_files < <(printf '%s\n' "${!file_durations[@]}" | sort)
 115
 116 # Generate a random starting point within the total duration
 117 random_point=$(awk -v max="$total_duration" 'BEGIN{srand(); print rand()*max}')
 118
 119 # Find the file and offset corresponding to the random starting point
 120 accumulated_duration=0
 121 for file in "${sorted_files[@]}"; do
 122     duration="${file_durations["$file"]}"
 123     new_accumulated_duration=$(echo "$accumulated_duration + $duration" | bc)
 124     if (( $(echo "$random_point < $new_accumulated_duration" | bc -l) )); then
 125         offset=$(echo "$random_point - $accumulated_duration" | bc)
 126         yell "Starting playback from $offset seconds into file: $file"
 127
 128         # Create a playlist file
 129         playlist_file=$(mktemp)
 130         printf '%s\n' "${sorted_files[@]}" > "$playlist_file"
 131
 132         # Start playback using mpv
 133         mpv --playlist="$playlist_file" --start="$offset" \
 134             --playlist-start=$(($(printf '%s\n' "${sorted_files[@]}" | grep -n "^$file$" | cut -d: -f1)-1))
 135
 136         # Securely delete the playlist file
 137         if [[ -n "$playlist_file" && -f "$playlist_file" ]]; then
 138             rm "$playlist_file"; exit 0;
 139         else
 140             die "FATAL: playlist_file is either unset or not a valid file, skipping deletion.";
 141         fi;
 142     fi
 143     accumulated_duration="$new_accumulated_duration";
 144 done
 145
 146 die "FATAL: Could not find file corresponding to random point.";
 147