+#!/bin/bash
+# Desc: Extracts audio from video files
+# Usage: bk_export_audio.sh [input_dir] ([output_dir])
+# Version: 0.0.1
+
+declare -Ag appRollCall # Associative array for storing app status
+declare -Ag fileRollCall # Associative array for storing file status
+declare -Ag dirRollCall # Associative array for storing dir status
+
+yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
+die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
+try() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
+checkapp() {
+ # Desc: If arg is a command, save result in assoc array 'appRollCall'
+ # Usage: checkapp arg1 arg2 arg3 ...
+ # Version: 0.1.1
+ # Input: global assoc. array 'appRollCall'
+ # Output: adds/updates key(value) to global assoc array 'appRollCall'
+ # Depends: bash 5.0.3
+ local returnState
+
+ #===Process Args===
+ for arg in "$@"; do
+ if command -v "$arg" 1>/dev/null 2>&1; then # Check if arg is a valid command
+ appRollCall[$arg]="true";
+ if ! [ "$returnState" = "false" ]; then returnState="true"; fi;
+ else
+ appRollCall[$arg]="false"; returnState="false";
+ fi;
+ done;
+
+ #===Determine function return code===
+ if [ "$returnState" = "true" ]; then
+ return 0;
+ else
+ return 1;
+ fi;
+} # Check that app exists
+checkfile() {
+ # Desc: If arg is a file path, save result in assoc array 'fileRollCall'
+ # Usage: checkfile arg1 arg2 arg3 ...
+ # Version: 0.1.1
+ # Input: global assoc. array 'fileRollCall'
+ # Output: adds/updates key(value) to global assoc array 'fileRollCall';
+ # Output: returns 0 if app found, 1 otherwise
+ # Depends: bash 5.0.3
+ local returnState
+
+ #===Process Args===
+ for arg in "$@"; do
+ if [ -f "$arg" ]; then
+ fileRollCall["$arg"]="true";
+ if ! [ "$returnState" = "false" ]; then returnState="true"; fi;
+ else
+ fileRollCall["$arg"]="false"; returnState="false";
+ fi;
+ done;
+
+ #===Determine function return code===
+ if [ "$returnState" = "true" ]; then
+ return 0;
+ else
+ return 1;
+ fi;
+} # Check that file exists
+checkdir() {
+ # Desc: If arg is a dir path, save result in assoc array 'dirRollCall'
+ # Usage: checkdir arg1 arg2 arg3 ...
+ # Version 0.1.2
+ # Input: global assoc. array 'dirRollCall'
+ # Output: adds/updates key(value) to global assoc array 'dirRollCall';
+ # Output: returns 0 if all args are dirs; 1 otherwise
+ # Depends: Bash 5.0.3
+ local returnState
+
+ #===Process Args===
+ for arg in "$@"; do
+ if [ -z "$arg" ]; then
+ dirRollCall["(Unspecified Dirname(s))"]="false"; returnState="false";
+ elif [ -d "$arg" ]; then
+ dirRollCall["$arg"]="true";
+ if ! [ "$returnState" = "false" ]; then returnState="true"; fi
+ else
+ dirRollCall["$arg"]="false"; returnState="false";
+ fi
+ done
+
+ #===Determine function return code===
+ if [ "$returnState" = "true" ]; then
+ return 0;
+ else
+ return 1;
+ fi
+} # Check that dir exists
+displayMissing() {
+ # Desc: Displays missing apps, files, and dirs
+ # Usage: displayMissing
+ # Version 0.1.1
+ # Input: associative arrays: appRollCall, fileRollCall, dirRollCall
+ # Output: stderr: messages indicating missing apps, file, or dirs
+ # Depends: bash 5, checkAppFileDir()
+ local missingApps value appMissing missingFiles fileMissing
+ local missingDirs dirMissing
+
+ #==BEGIN Display errors==
+ #===BEGIN Display Missing Apps===
+ missingApps="Missing apps :";
+ #for key in "${!appRollCall[@]}"; do echo "DEBUG:$key => ${appRollCall[$key]}"; done
+ for key in "${!appRollCall[@]}"; do
+ value="${appRollCall[$key]}";
+ if [ "$value" = "false" ]; then
+ #echo "DEBUG:Missing apps: $key => $value";
+ missingApps="$missingApps""$key ";
+ appMissing="true";
+ fi;
+ done;
+ if [ "$appMissing" = "true" ]; then # Only indicate if an app is missing.
+ echo "$missingApps" 1>&2;
+ fi;
+ unset value;
+ #===END Display Missing Apps===
+
+ #===BEGIN Display Missing Files===
+ missingFiles="Missing files:";
+ #for key in "${!fileRollCall[@]}"; do echo "DEBUG:$key => ${fileRollCall[$key]}"; done
+ for key in "${!fileRollCall[@]}"; do
+ value="${fileRollCall[$key]}";
+ if [ "$value" = "false" ]; then
+ #echo "DEBUG:Missing files: $key => $value";
+ missingFiles="$missingFiles""$key ";
+ fileMissing="true";
+ fi;
+ done;
+ if [ "$fileMissing" = "true" ]; then # Only indicate if an app is missing.
+ echo "$missingFiles" 1>&2;
+ fi;
+ unset value;
+ #===END Display Missing Files===
+
+ #===BEGIN Display Missing Directories===
+ missingDirs="Missing dirs:";
+ #for key in "${!dirRollCall[@]}"; do echo "DEBUG:$key => ${dirRollCall[$key]}"; done
+ for key in "${!dirRollCall[@]}"; do
+ value="${dirRollCall[$key]}";
+ if [ "$value" = "false" ]; then
+ #echo "DEBUG:Missing dirs: $key => $value";
+ missingDirs="$missingDirs""$key ";
+ dirMissing="true";
+ fi;
+ done;
+ if [ "$dirMissing" = "true" ]; then # Only indicate if an dir is missing.
+ echo "$missingDirs" 1>&2;
+ fi;
+ unset value;
+ #===END Display Missing Directories===
+
+ #==END Display errors==
+} # Display missing apps, files, dirs
+showUsage() {
+ # Desc: Display script usage information
+ # Usage: showUsage
+ # Version 0.0.1
+ # Input: none
+ # Output: stdout
+ # Depends: GNU-coreutils 8.30 (cat)
+ cat <<'EOF'
+ USAGE:
+ bk_export_audio.sh [DIR in] ([DIR out])
+
+ EXAMPLE:
+ bk_export_audio.sh ./videos/ ./exported_audio/
+ bk_export_audio.sh ./videos/
+EOF
+} # Display information on how to use this script.
+get_audio_format() {
+ # Desc: Gets audio format of file as string
+ # Usage: get_audio_format arg1
+ # Depends: ffprobe
+ # Version: 0.0.1
+ # Input: arg1: input file path
+ # Output: stdout (if valid audio format)
+ # exit code 0 if audio file; 1 otherwise
+ # Example: get_audio_format myvideo.mp4
+ # Note: Would return "opus" if full ffprobe report had 'Audio: opus, 48000 Hz, stereo, fltp'
+ # Note: Not tested with videos containing multiple video streams
+ # Ref/Attrib: [1] https://stackoverflow.com/questions/5618363/is-there-a-way-to-use-ffmpeg-to-determine-the-encoding-of-a-file-before-transcod
+ # [2] https://stackoverflow.com/questions/44123532/how-to-find-out-the-file-extension-for-extracting-audio-tracks-with-ffmpeg-and-p#comment88464070_50723126
+ local audio_format file_in;
+ local return_state;
+ file_in="$1";
+
+ # Return error exit code if not audio file
+ ## Return error if ffprobe itself exited on error
+ if ! ffprobe -v error -select_streams a -show_entries stream=codec_name -of default=nokey=1:noprint_wrappers=1 "$file_in" 1>/dev/null 2>&1; then
+ return_state="false";
+ fi;
+
+ # Get audio format
+ audio_format="$(ffprobe -v error -select_streams a -show_entries stream=codec_name -of default=nokey=1:noprint_wrappers=1 "$file_in")"; # see [1]
+
+ ## Return error if audio format is incorrectly formatted (e.g. reject if contains spaces)
+ pattern="^[[:alnum:]]+$"; # alphanumeric string with no spaces
+ if [[ $audio_format =~ $pattern ]]; then
+ return_state="true";
+ # Report audio format
+ echo "$audio_format";
+ else
+ return_state="false";
+ fi;
+
+ # Report exit code
+ if [[ $return_state = "true" ]]; then
+ return 0;
+ else
+ return 1;
+ fi;
+} # Get audio format as stdout
+extract_audio_file() {
+ # Desc: Use ffmpeg to creates audio file from input video file
+ # Usage: extract_audio_file arg1 arg2 arg3
+ # Depends: ffmpeg
+ # Input: arg1: input video file path
+ # arg2: desired output file extension
+ # arg3: output dir path
+ # Output: audio file at path [arg3]/[arg1].[arg2]
+ local file_in file_in_ext dir_out file_in_basename;
+ file_in="$1";
+ file_in_ext="$2";
+ dir_out="$3";
+
+ # Extract audio file
+ file_in_basename="$(basename "$file_in")";
+ ffmpeg -i "$file_in" -vn -acodec copy "$dir_out"/"$file_in_basename"."$file_in_ext";
+}
+
+main() {
+ script_pwd="$(pwd)";
+ dir_in="$1";
+ dir_out="$2";
+
+ # Check argument count
+ if [[ $# -lt 1 ]]; then
+ showUsage;
+ die "ERROR:Not enough arguments:$#";
+ fi;
+
+ # Check apps, dirs
+ checkapp ffmpeg ffprobe date;
+ displayMissing;
+
+ if ! checkdir "$dir_in"; then
+ showUsage;
+ displayMissing;
+ die "ERROR:Missing input directory."
+ fi;
+ if ! checkdir "$dir_out"; then
+ yell "NOTICE:Output directory not specified. Creating output directory in current working directory:$script_pwd";
+ timestamp="$(date +%Y%m%dT%H%M%S%z)"; # iso-8601 without separators
+ dir_out="$script_pwd"/"$timestamp"..output;
+ try mkdir "$dir_out";
+ fi;
+
+ # Do work
+ yell "DEBUG:dir_in:$dir_in":
+ yell "DEBUG:dir_out:$dir_out";
+ for file in "$dir_in"/*; do
+ aud_format="$(get_audio_format "$file")"; # Get audio format as file extension string
+ file_basename="$(basename "$file")"; # Get basename for debugging
+ yell "DEBUG:file_basename:$file_basename";
+ yell "DEBUG:aud_format:$aud_format";
+ yell "DEBUG:";
+
+ # Ignore files that return blank $aud_format
+ if [[ -z $aud_format ]]; then
+ yell "DEBUG:Not an audio file:$file";
+ continue;
+ fi;
+
+ extract_audio_file "$file" "$aud_format" "$dir_out";
+ done;
+} # main program
+
+main "$@";
+
+# Author: Steven Baltaktei Sandoval
+# License: GPLv3+
projects / BK-2020-03.git / commitdiff