user/rand_media_pl.sh

   1 #!/usr/bin/env bash
   2 # Description:
   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 #   - Uses an EDL file to specify the starting offset for the first file.
   9 # Usage: rand_media_pl.sh [DIR]
  10 # Version: 0.0.4
  11 # Dependencies: Bash 4, ffprobe, mpv, bc, shuf
  12
  13 yell() { echo "$0: $*" >&2; } # Print script path and all args to stderr
  14 die() { yell "$*"; exit 111; } # Same as yell() but exits with code 111
  15 must() { "$@" || die "cannot $*"; } # Runs args as command, reports args if command fails
  16
  17 # Configurable variables
  18 SEARCH_DIR="${1:-.}"  # Default to current directory if no argument is provided
  19 MAX_DEPTH=8
  20 EXTENSIONS=("*.flac" "*.mp3" "*.opus" "*.m4a" "*.m4b" "*.mp4" "*.mkv" "*.webm")
  21 CACHE_FILE=".playlist_cache"
  22
  23 declare -gA file_durations
  24 declare total_duration
  25
  26 # Function to prompt the user
  27 prompt_yes_no() {
  28     yell "STATUS: User input required."
  29     local prompt_message="$1"
  30     local user_input
  31     while true; do
  32         read -rp "$prompt_message [y/n]: " user_input
  33         case "$user_input" in
  34             [Yy]*) return 0 ;;
  35             [Nn]*) return 1 ;;
  36             *) echo "Please answer yes or no." ;;
  37         esac
  38     done
  39 }
  40
  41 # Function to find files with specified extensions
  42 find_media_files() {
  43     yell "STATUS: Finding media files."
  44     local find_cmd=("find" "-L" "$SEARCH_DIR" "-maxdepth" "$MAX_DEPTH" "-type" "f" "(")
  45     for ext in "${EXTENSIONS[@]}"; do
  46         find_cmd+=("-iname" "$ext" "-o")
  47     done
  48     # Remove the last "-o" and add ")"
  49     unset 'find_cmd[-1]'
  50     find_cmd+=(")")
  51     "${find_cmd[@]}"
  52 }
  53
  54 # Function to generate the playlist cache
  55 generate_playlist_cache() {
  56     yell "Generating playlist cache. This may take a while..."
  57     # Initialize or empty the cache file
  58     : > "$CACHE_FILE"  # Truncate or create the cache file
  59
  60     total_duration=0
  61     while IFS= read -r file; do
  62         # Get the duration using ffprobe
  63         duration=$(ffprobe -v error -show_entries format=duration \
  64             -of default=noprint_wrappers=1:nokey=1 "$file")
  65         declare -p file duration 1>&2  # Debugging statement
  66
  67         # Validate the duration
  68         if [[ -n "$duration" && "$duration" =~ ^[0-9]+(\.[0-9]+)?$ ]]; then
  69             # Append the file path and duration to the cache file
  70             printf "%s|%s\n" "$file" "$duration" >> "$CACHE_FILE"
  71             total_duration=$(echo "$total_duration + $duration" | bc)
  72         else
  73             yell "WARNING: Invalid duration '$duration' for file '$file', skipping." 1>&2
  74         fi
  75     done < <(find_media_files | sort)
  76
  77     total_duration_s=$(printf "%.1f" "$total_duration")
  78     total_duration_h=$(echo "scale=1; $total_duration / 3600" | bc -l)
  79
  80     yell "Total duration of playlist: ${total_duration_s} seconds (${total_duration_h} hours)."
  81 }
  82
  83 # Function to read the playlist cache
  84 read_playlist_cache() {
  85     # Input: file_durations associative array
  86     #        total_duration scalar
  87     yell "STATUS: Reading playlist cache."
  88
  89     total_duration=0
  90     while IFS='|' read -r file duration; do
  91         declare -p file duration 1>&2  # Debugging statement
  92
  93         # Validate the duration
  94         if [[ -n "$duration" && "$duration" =~ ^[0-9]+(\.[0-9]+)?$ ]]; then
  95             file_durations["$file"]="$duration"
  96             total_duration=$(echo "$total_duration + $duration" | bc)
  97         else
  98             yell "WARNING: Invalid duration '$duration' for file '$file', skipping." 1>&2
  99         fi
 100     done < "$CACHE_FILE"
 101 }
 102
 103 # Main script
 104 if [[ -f "$CACHE_FILE" ]]; then
 105     if prompt_yes_no "Playlist cache detected. Do you want to use it? (Faster)"; then
 106         read_playlist_cache
 107     else
 108         generate_playlist_cache
 109         read_playlist_cache
 110     fi
 111 else
 112     generate_playlist_cache
 113     read_playlist_cache
 114 fi
 115
 116 # Check if any files were found
 117 if [[ ${#file_durations[@]} -eq 0 ]]; then
 118     declare -p file_durations 1>&2
 119     die "FATAL: No media files found."
 120 fi
 121
 122 # Ensure total_duration is not empty
 123 if [[ -z "$total_duration" ]]; then
 124     die "FATAL: total_duration is empty."
 125 fi
 126
 127 # Convert total_duration to an integer
 128 total_duration_int=$(printf "%.0f" "$total_duration")
 129
 130 # Check if total_duration_int is a valid integer
 131 if ! [[ "$total_duration_int" =~ ^[0-9]+$ ]]; then
 132     die "FATAL: total_duration_int is not a valid integer."
 133 fi
 134
 135 # Generate a random integer between 0 and total_duration_int - 1
 136 random_point=$(shuf -i 0-$((total_duration_int - 1)) -n1)
 137 yell "DEBUG: total_duration=$total_duration, total_duration_int=$total_duration_int, random_point=$random_point" 1>&2
 138
 139 # Get sorted list of files
 140 mapfile -t sorted_files < <(printf '%s\n' "${!file_durations[@]}" | sort)
 141
 142 # Find the file and offset corresponding to the random starting point
 143 accumulated_duration=0
 144 accumulated_duration_int=0
 145
 146 for idx in "${!sorted_files[@]}"; do
 147     file="${sorted_files[$idx]}"
 148     duration="${file_durations["$file"]}"
 149     declare -p idx file duration accumulated_duration 1>&2  # Debugging statement
 150
 151     # Validate the duration
 152     if [[ -n "$duration" && "$duration" =~ ^[0-9]+(\.[0-9]+)?$ ]]; then
 153         new_accumulated_duration=$(echo "$accumulated_duration + $duration" | bc)
 154         # Convert accumulated durations to integers for comparison
 155         accumulated_duration_int=$(printf "%.0f" "$accumulated_duration")
 156         new_accumulated_duration_int=$(printf "%.0f" "$new_accumulated_duration")
 157     else
 158         yell "WARNING: Invalid duration '$duration' for file '$file', skipping." 1>&2
 159         continue
 160     fi
 161
 162     if (( random_point < new_accumulated_duration_int )); then
 163         offset=$(echo "$random_point - $accumulated_duration_int" | bc)
 164         yell "Starting playback from $offset seconds into file: $file"
 165
 166         # Create an EDL file
 167         edl_file=$(mktemp)
 168         echo "# mpv EDL v0" > "$edl_file"
 169
 170         # First line: file with offset
 171         printf '%s,%s\n' "$file" "$offset" >> "$edl_file"
 172
 173         # Append the rest of the files
 174         declare -p file offset idx sorted_files edl_file 1>&2; # debug
 175         for (( i=idx+1; i<${#sorted_files[@]}; i++ )); do
 176             next_file="${sorted_files[$i]}"
 177             yell "STATUS:Adding:$next_file";
 178             printf '%s\n' "$next_file" >> "$edl_file"
 179         done
 180
 181         # Start playback using mpv
 182         mpv "$edl_file"
 183
 184         # Securely delete the EDL file
 185         if [[ -n "$edl_file" && -f "$edl_file" ]]; then
 186             rm "$edl_file"
 187             exit 0
 188         else
 189             die "FATAL: edl_file is either unset or not a valid file, skipping deletion."
 190         fi
 191     fi
 192     accumulated_duration="$new_accumulated_duration"
 193     accumulated_duration_int="$new_accumulated_duration_int"
 194 done
 195
 196 die "FATAL: Could not find file corresponding to random point."