unitproc/bk_export_audio.sh

   1 #!/bin/bash
   2 # Desc: Extracts audio from video files
   3 # Usage: bk_export_audio.sh [input_dir] ([output_dir])
   4 # Version: 0.0.2
   5
   6 declare -Ag appRollCall # Associative array for storing app status
   7 declare -Ag fileRollCall # Associative array for storing file status
   8 declare -Ag dirRollCall # Associative array for storing dir status
   9
  10 yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
  11 die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
  12 try() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
  13 checkapp() {
  14     # Desc: If arg is a command, save result in assoc array 'appRollCall'
  15     # Usage: checkapp arg1 arg2 arg3 ...
  16     # Version: 0.1.1
  17     # Input: global assoc. array 'appRollCall'
  18     # Output: adds/updates key(value) to global assoc array 'appRollCall'
  19     # Depends: bash 5.0.3
  20     local returnState
  21
  22     #===Process Args===
  23     for arg in "$@"; do
  24         if command -v "$arg" 1>/dev/null 2>&1; then # Check if arg is a valid command
  25             appRollCall[$arg]="true";
  26             if ! [ "$returnState" = "false" ]; then returnState="true"; fi;
  27         else
  28             appRollCall[$arg]="false"; returnState="false";
  29         fi;
  30     done;
  31
  32     #===Determine function return code===
  33     if [ "$returnState" = "true" ]; then
  34         return 0;
  35     else
  36         return 1;
  37     fi;
  38 } # Check that app exists
  39 checkfile() {
  40     # Desc: If arg is a file path, save result in assoc array 'fileRollCall'
  41     # Usage: checkfile arg1 arg2 arg3 ...
  42     # Version: 0.1.1
  43     # Input: global assoc. array 'fileRollCall'
  44     # Output: adds/updates key(value) to global assoc array 'fileRollCall';
  45     # Output: returns 0 if app found, 1 otherwise
  46     # Depends: bash 5.0.3
  47     local returnState
  48
  49     #===Process Args===
  50     for arg in "$@"; do
  51         if [ -f "$arg" ]; then
  52             fileRollCall["$arg"]="true";
  53             if ! [ "$returnState" = "false" ]; then returnState="true"; fi;
  54         else
  55             fileRollCall["$arg"]="false"; returnState="false";
  56         fi;
  57     done;
  58
  59     #===Determine function return code===
  60     if [ "$returnState" = "true" ]; then
  61         return 0;
  62     else
  63         return 1;
  64     fi;
  65 } # Check that file exists
  66 checkdir() {
  67     # Desc: If arg is a dir path, save result in assoc array 'dirRollCall'
  68     # Usage: checkdir arg1 arg2 arg3 ...
  69     # Version 0.1.2
  70     # Input: global assoc. array 'dirRollCall'
  71     # Output: adds/updates key(value) to global assoc array 'dirRollCall';
  72     # Output: returns 0 if all args are dirs; 1 otherwise
  73     # Depends: Bash 5.0.3
  74     local returnState
  75
  76     #===Process Args===
  77     for arg in "$@"; do
  78         if [ -z "$arg" ]; then
  79             dirRollCall["(Unspecified Dirname(s))"]="false"; returnState="false";
  80         elif [ -d "$arg" ]; then
  81             dirRollCall["$arg"]="true";
  82             if ! [ "$returnState" = "false" ]; then returnState="true"; fi
  83         else
  84             dirRollCall["$arg"]="false"; returnState="false";
  85         fi
  86     done
  87
  88     #===Determine function return code===
  89     if [ "$returnState" = "true" ]; then
  90         return 0;
  91     else
  92         return 1;
  93     fi
  94 } # Check that dir exists
  95 displayMissing() {
  96     # Desc: Displays missing apps, files, and dirs
  97     # Usage: displayMissing
  98     # Version 0.1.1
  99     # Input: associative arrays: appRollCall, fileRollCall, dirRollCall
 100     # Output: stderr: messages indicating missing apps, file, or dirs
 101     # Depends: bash 5, checkAppFileDir()
 102     local missingApps value appMissing missingFiles fileMissing
 103     local missingDirs dirMissing
 104
 105     #==BEGIN Display errors==
 106     #===BEGIN Display Missing Apps===
 107     missingApps="Missing apps  :";
 108     #for key in "${!appRollCall[@]}"; do echo "DEBUG:$key => ${appRollCall[$key]}"; done
 109     for key in "${!appRollCall[@]}"; do
 110         value="${appRollCall[$key]}";
 111         if [ "$value" = "false" ]; then
 112             #echo "DEBUG:Missing apps: $key => $value";
 113             missingApps="$missingApps""$key ";
 114             appMissing="true";
 115         fi;
 116     done;
 117     if [ "$appMissing" = "true" ]; then  # Only indicate if an app is missing.
 118         echo "$missingApps" 1>&2;
 119     fi;
 120     unset value;
 121     #===END Display Missing Apps===
 122
 123     #===BEGIN Display Missing Files===
 124     missingFiles="Missing files:";
 125     #for key in "${!fileRollCall[@]}"; do echo "DEBUG:$key => ${fileRollCall[$key]}"; done
 126     for key in "${!fileRollCall[@]}"; do
 127         value="${fileRollCall[$key]}";
 128         if [ "$value" = "false" ]; then
 129             #echo "DEBUG:Missing files: $key => $value";
 130             missingFiles="$missingFiles""$key ";
 131             fileMissing="true";
 132         fi;
 133     done;
 134     if [ "$fileMissing" = "true" ]; then  # Only indicate if an app is missing.
 135         echo "$missingFiles" 1>&2;
 136     fi;
 137     unset value;
 138     #===END Display Missing Files===
 139
 140     #===BEGIN Display Missing Directories===
 141     missingDirs="Missing dirs:";
 142     #for key in "${!dirRollCall[@]}"; do echo "DEBUG:$key => ${dirRollCall[$key]}"; done
 143     for key in "${!dirRollCall[@]}"; do
 144         value="${dirRollCall[$key]}";
 145         if [ "$value" = "false" ]; then
 146             #echo "DEBUG:Missing dirs: $key => $value";
 147             missingDirs="$missingDirs""$key ";
 148             dirMissing="true";
 149         fi;
 150     done;
 151     if [ "$dirMissing" = "true" ]; then  # Only indicate if an dir is missing.
 152         echo "$missingDirs" 1>&2;
 153     fi;
 154     unset value;
 155     #===END Display Missing Directories===
 156
 157     #==END Display errors==
 158 } # Display missing apps, files, dirs
 159 showUsage() {
 160     # Desc: Display script usage information
 161     # Usage: showUsage
 162     # Version 0.0.1
 163     # Input: none
 164     # Output: stdout
 165     # Depends: GNU-coreutils 8.30 (cat)
 166     cat <<'EOF'
 167     USAGE:
 168         bk_export_audio.sh [DIR in] ([DIR out])
 169
 170     EXAMPLE:
 171       bk_export_audio.sh ./videos/ ./exported_audio/
 172       bk_export_audio.sh ./videos/
 173 EOF
 174 } # Display information on how to use this script.
 175 get_audio_format() {
 176     # Desc: Gets audio format of file as string
 177     # Usage: get_audio_format arg1
 178     # Depends: ffprobe
 179     # Version: 0.0.1
 180     # Input: arg1: input file path
 181     # Output: stdout (if valid audio format)
 182     #         exit code 0 if audio file; 1 otherwise
 183     # Example: get_audio_format myvideo.mp4
 184     #   Note: Would return "opus" if full ffprobe report had 'Audio: opus, 48000 Hz, stereo, fltp'
 185     # Note: Not tested with videos containing multiple video streams
 186     # Ref/Attrib: [1] https://stackoverflow.com/questions/5618363/is-there-a-way-to-use-ffmpeg-to-determine-the-encoding-of-a-file-before-transcod
 187     #             [2] https://stackoverflow.com/questions/44123532/how-to-find-out-the-file-extension-for-extracting-audio-tracks-with-ffmpeg-and-p#comment88464070_50723126
 188     local audio_format file_in;
 189     local return_state;
 190     file_in="$1";
 191
 192     # Return error exit code if not audio file
 193     ## Return error if ffprobe itself exited on error
 194     if ! ffprobe -v error -select_streams a -show_entries stream=codec_name -of default=nokey=1:noprint_wrappers=1 "$file_in" 1>/dev/null 2>&1; then
 195         return_state="false";
 196     fi;
 197
 198     # Get audio format
 199     audio_format="$(ffprobe -v error -select_streams a -show_entries stream=codec_name -of default=nokey=1:noprint_wrappers=1 "$file_in")"; # see [1]
 200
 201     ## Return error if audio format is incorrectly formatted (e.g. reject if contains spaces)
 202     pattern="^[[:alnum:]]+$"; # alphanumeric string with no spaces
 203     if [[ $audio_format =~ $pattern ]]; then
 204         return_state="true";
 205         # Report audio format
 206         echo "$audio_format";
 207     else
 208         return_state="false";
 209     fi;
 210
 211     # Report exit code
 212     if [[ $return_state = "true" ]]; then
 213         return 0;
 214     else
 215         return 1;
 216     fi;
 217 } # Get audio format as stdout
 218 extract_audio_file() {
 219     # Desc: Use ffmpeg to creates audio file from input video file
 220     # Usage: extract_audio_file arg1 arg2 arg3
 221     # Depends: ffmpeg
 222     # Input: arg1: input video file path
 223     #        arg2: desired output file extension
 224     #        arg3: output dir path
 225     # Output: audio file at path [arg3]/[arg1].[arg2]
 226     local file_in file_in_ext dir_out file_in_basename;
 227     file_in="$1";
 228     file_in_ext="$2";
 229     dir_out="$3";
 230
 231     # Extract audio file
 232     file_in_basename="$(basename "$file_in")";
 233     ffmpeg -i "$file_in" -vn -acodec copy "$dir_out"/"$file_in_basename"."$file_in_ext";
 234 } # Create audio file from video file
 235
 236 main() {
 237     script_pwd="$(pwd)";
 238     dir_in="$1";
 239     dir_out="$2";
 240
 241     # Check argument count
 242     if [[ $# -lt 1 ]]; then
 243         showUsage;
 244         die "ERROR:Not enough arguments:$#";
 245     fi;
 246
 247     # Check apps, dirs
 248     checkapp ffmpeg ffprobe date;
 249     displayMissing;
 250
 251     if ! checkdir "$dir_in"; then
 252         showUsage;
 253         displayMissing;
 254         die "ERROR:Missing input directory."
 255     fi;
 256     if ! checkdir "$dir_out"; then
 257         yell "NOTICE:Output directory not specified. Creating output directory in current working directory:$script_pwd";
 258         timestamp="$(date +%Y%m%dT%H%M%S%z)"; # iso-8601 without separators
 259         dir_out="$script_pwd"/"$timestamp"..output;
 260         try mkdir "$dir_out";
 261     fi;
 262
 263     # Do work
 264     yell "DEBUG:dir_in:$dir_in":
 265     yell "DEBUG:dir_out:$dir_out";
 266     for file in "$dir_in"/*; do
 267         aud_format="$(get_audio_format "$file")"; # Get audio format as file extension string
 268         file_basename="$(basename "$file")"; # Get basename for debugging
 269         yell "DEBUG:file_basename:$file_basename";
 270         yell "DEBUG:aud_format:$aud_format";
 271         yell "DEBUG:";
 272
 273         # Ignore files that return blank $aud_format
 274         if [[ -z $aud_format ]]; then
 275             yell "DEBUG:Not an audio file:$file";
 276             continue;
 277         fi;
 278
 279         extract_audio_file "$file" "$aud_format" "$dir_out";
 280     done;
 281 } # main program
 282
 283 main "$@";
 284
 285 # Author: Steven Baltaktei Sandoval
 286 # License: GPLv3+