user/convert_file_to_flac.sh

   1 #!/usr/bin/env bash
   2 # Desc: Converts file readable by ffmpeg to FLAC audio file
   3 # Usage: convert_file_to_flac.sh [path]
   4 # Version: 0.0.3
   5 # Ref/Attrib: [1] Convert audio file to FLAC with ffmpeg? https://superuser.com/a/802126
   6 #             [2] How to specify flac compression level when converting with avconv? https://askubuntu.com/questions/544651/
   7 #             [3] How can I extract audio from video with ffmpeg? https://stackoverflow.com/a/27413824
   8 # Depends: ffmpeg version 4.4.2, ffprobe version 4.4.2, bash version 5.1.16
   9
  10 declare -Ag appRollCall # Associative array for storing app status
  11 declare -Ag fileRollCall # Associative array for storing file status
  12 declare -Ag dirRollCall # Associative array for storing dir status
  13
  14 yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
  15 die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
  16 try() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
  17 checkapp() {
  18     # Desc: If arg is a command, save result in assoc array 'appRollCall'
  19     # Usage: checkapp arg1 arg2 arg3 ...
  20     # Version: 0.1.1
  21     # Input: global assoc. array 'appRollCall'
  22     # Output: adds/updates key(value) to global assoc array 'appRollCall'
  23     # Depends: bash 5.0.3
  24     local returnState
  25
  26     #===Process Args===
  27     for arg in "$@"; do
  28         if command -v "$arg" 1>/dev/null 2>&1; then # Check if arg is a valid command
  29             appRollCall[$arg]="true";
  30             if ! [ "$returnState" = "false" ]; then returnState="true"; fi;
  31         else
  32             appRollCall[$arg]="false"; returnState="false";
  33         fi;
  34     done;
  35
  36     #===Determine function return code===
  37     if [ "$returnState" = "true" ]; then
  38         return 0;
  39     else
  40         return 1;
  41     fi;
  42 } # Check that app exists
  43 checkfile() {
  44     # Desc: If arg is a file path, save result in assoc array 'fileRollCall'
  45     # Usage: checkfile arg1 arg2 arg3 ...
  46     # Version: 0.1.1
  47     # Input: global assoc. array 'fileRollCall'
  48     # Output: adds/updates key(value) to global assoc array 'fileRollCall';
  49     # Output: returns 0 if app found, 1 otherwise
  50     # Depends: bash 5.0.3
  51     local returnState
  52
  53     #===Process Args===
  54     for arg in "$@"; do
  55         if [ -f "$arg" ]; then
  56             fileRollCall["$arg"]="true";
  57             if ! [ "$returnState" = "false" ]; then returnState="true"; fi;
  58         else
  59             fileRollCall["$arg"]="false"; returnState="false";
  60         fi;
  61     done;
  62
  63     #===Determine function return code===
  64     if [ "$returnState" = "true" ]; then
  65         return 0;
  66     else
  67         return 1;
  68     fi;
  69 } # Check that file exists
  70 checkdir() {
  71     # Desc: If arg is a dir path, save result in assoc array 'dirRollCall'
  72     # Usage: checkdir arg1 arg2 arg3 ...
  73     # Version 0.1.2
  74     # Input: global assoc. array 'dirRollCall'
  75     # Output: adds/updates key(value) to global assoc array 'dirRollCall';
  76     # Output: returns 0 if all args are dirs; 1 otherwise
  77     # Depends: Bash 5.0.3
  78     local returnState
  79
  80     #===Process Args===
  81     for arg in "$@"; do
  82         if [ -z "$arg" ]; then
  83             dirRollCall["(Unspecified Dirname(s))"]="false"; returnState="false";
  84         elif [ -d "$arg" ]; then
  85             dirRollCall["$arg"]="true";
  86             if ! [ "$returnState" = "false" ]; then returnState="true"; fi
  87         else
  88             dirRollCall["$arg"]="false"; returnState="false";
  89         fi
  90     done
  91
  92     #===Determine function return code===
  93     if [ "$returnState" = "true" ]; then
  94         return 0;
  95     else
  96         return 1;
  97     fi
  98 } # Check that dir exists
  99 displayMissing() {
 100     # Desc: Displays missing apps, files, and dirs
 101     # Usage: displayMissing
 102     # Version 1.0.0
 103     # Input: associative arrays: appRollCall, fileRollCall, dirRollCall
 104     # Output: stderr: messages indicating missing apps, file, or dirs
 105     # Output: returns exit code 0 if nothing missing; 1 otherwise
 106     # Depends: bash 5, checkAppFileDir()
 107     local missingApps value appMissing missingFiles fileMissing
 108     local missingDirs dirMissing
 109
 110     #==BEGIN Display errors==
 111     #===BEGIN Display Missing Apps===
 112     missingApps="Missing apps  :";
 113     #for key in "${!appRollCall[@]}"; do echo "DEBUG:$key => ${appRollCall[$key]}"; done
 114     for key in "${!appRollCall[@]}"; do
 115         value="${appRollCall[$key]}";
 116         if [ "$value" = "false" ]; then
 117             #echo "DEBUG:Missing apps: $key => $value";
 118             missingApps="$missingApps""$key ";
 119             appMissing="true";
 120         fi;
 121     done;
 122     if [ "$appMissing" = "true" ]; then  # Only indicate if an app is missing.
 123         echo "$missingApps" 1>&2;
 124     fi;
 125     unset value;
 126     #===END Display Missing Apps===
 127
 128     #===BEGIN Display Missing Files===
 129     missingFiles="Missing files:";
 130     #for key in "${!fileRollCall[@]}"; do echo "DEBUG:$key => ${fileRollCall[$key]}"; done
 131     for key in "${!fileRollCall[@]}"; do
 132         value="${fileRollCall[$key]}";
 133         if [ "$value" = "false" ]; then
 134             #echo "DEBUG:Missing files: $key => $value";
 135             missingFiles="$missingFiles""$key ";
 136             fileMissing="true";
 137         fi;
 138     done;
 139     if [ "$fileMissing" = "true" ]; then  # Only indicate if an app is missing.
 140         echo "$missingFiles" 1>&2;
 141     fi;
 142     unset value;
 143     #===END Display Missing Files===
 144
 145     #===BEGIN Display Missing Directories===
 146     missingDirs="Missing dirs:";
 147     #for key in "${!dirRollCall[@]}"; do echo "DEBUG:$key => ${dirRollCall[$key]}"; done
 148     for key in "${!dirRollCall[@]}"; do
 149         value="${dirRollCall[$key]}";
 150         if [ "$value" = "false" ]; then
 151             #echo "DEBUG:Missing dirs: $key => $value";
 152             missingDirs="$missingDirs""$key ";
 153             dirMissing="true";
 154         fi;
 155     done;
 156     if [ "$dirMissing" = "true" ]; then  # Only indicate if an dir is missing.
 157         echo "$missingDirs" 1>&2;
 158     fi;
 159     unset value;
 160     #===END Display Missing Directories===
 161
 162     #==END Display errors==
 163     #==BEGIN Determine function return code===
 164     if [ "$appMissing" == "true" ] || [ "$fileMissing" == "true" ] || [ "$dirMissing" == "true" ]; then
 165         return 1;
 166     else
 167         return 0;
 168     fi
 169     #==END Determine function return code===
 170 } # Display missing apps, files, dirs
 171 check_parsable_audio_ffprobe() {
 172     # Desc: Checks if ffprobe returns valid audio codec name for file
 173     # Usage: check_parsable_audio_ffprobe [path FILE]
 174     # Version: 0.0.1
 175     # Input: arg1: file path
 176     # Output: exit code 0 if returns valid codec name; 1 otherwise
 177     # Depends: ffprobe, die()
 178     local file_in ffprobe_out
 179
 180     if [[ $# -ne 1 ]]; then die "ERROR:Invalid number of args:$#"; fi;
 181
 182     file_in="$1";
 183
 184     # Check if ffprobe detects an audio stream
 185     if ffprobe -v error -select_streams a -show_entries stream=codec_name -of default=nokey=1:noprint_wrappers=1 "$file_in" 1>/dev/null 2>&1; then
 186         return_state="true";
 187     else
 188         return_state="false";
 189     fi;
 190
 191     # Fail if ffprobe returns no result
 192     ffprobe_out="$(ffprobe -v error -select_streams a -show_entries stream=codec_name -of default=nokey=1:noprint_wrappers=1 "$file_in")";
 193     if [[ -z $ffprobe_out ]]; then
 194         return_state="false";
 195     fi;
 196
 197     # Report exit code
 198     if [[ $return_state = "true" ]]; then
 199         return 0;
 200     else
 201         return 1;
 202     fi;
 203 } # Checks if file has valid codec name using ffprobe
 204 main() {
 205     # Check inputs
 206     if [[ ! -f $1 ]]; then die "FATAL:Not a file:$1"; fi;
 207     if [[ $# -ne 1 ]]; then die "FATAL:Arguments not equal to 1:$#"; fi;
 208
 209     # Check depends
 210     if ! checkapp ffmpeg ffprobe; then
 211         displayMissing;
 212         die "FATAL:Missing apps"; fi;
 213
 214
 215     # Check file is parsable by ffprobe
 216     if ! check_parsable_audio_ffprobe "$1"; then
 217         die "FATAL:Not an audio file:$1"; fi;
 218
 219     # Convert file to FLAC. See [1], [2]
 220     try ffmpeg -i "$1" -vn -c:a flac -compression_level 12 "$1".flac
 221 }; # main program
 222
 223 main "$@";
 224
 225 # Author: Steven Baltakatei Sandoval
 226 # License: GPLv3+