/usr/local/bin/ffmpeg: cannot execute binary file - bash

Question

Want to convert my m4a files into mp3 files using a script. It would save some time... I have over 100 GB of music files.
OS: OSX10.14 / Terminal vs Bash script
I can run ffmpeg -v 5 -y -i musicFile.m4a -acodec libmp3lame -ac 2 -b:a 320k musicFile.mp3 from the terminal. It converts the file and I can see and play the file from itunes.
When I run the same from a bash script it fails to convert.
ffmpeg -v 5 -y -i $ENTRY_FILE -acodec libmp3lame -ac 2 -b:a 320k $MP3NAME
My ipod nano just died and I got a new mp3 player. Now I need to convert my itunes files from AAC format to MP3.
ffmpeg is an established video and music file converter.
When I run it from the bash script I tried a few things.
I added ./ in front of the file, that failed because it was installed under /usr/local/bin and not under the same directory.
I also tried sh ffmpeg... and that gave me the cannot execute a binary file.
#!/usr/bin/env bash
# convert m4a file to mp3
set -e
file_convert() {
ENTRY_FILE=$(printf %q "${entry}")
FILE_NAME=$(printf %q "$(basename "${entry}")")
DIR=$(printf %q "$(dirname "${entry}")")
NAME="${FILE_NAME%.*}"
EXT="${FILE_NAME##*.}"
MP3NAME="${DIR}/${NAME}.mp3"
printf "%*s%s\n" $((indent+2)) '' "$ENTRY_FILE"
printf "%*s\tNew File :\t%s\n" $((indent+2)) '' "$MP3NAME"
if [ $EXT == "m4a" ]
then
printf "%*s\tConverting: \t%s\n" $((index+2)) '' "$ENTRY_FILE"
ffmpeg -v 5 -y -i $ENTRY_FILE -acodec libmp3lame -ac 2 -b:a 320k $MP3NAME
fi
}
walk() {
local indent="${2:-0}"
printf "\n%*s%s\n\n" "$indent" '' "$1"
# If the entry is a file convert it
for entry in "$1"/*; do [[ -f "$entry" ]] && file_convert; done
# If the entry is a directory recurse
for entry in "$1"/*; do [[ -d "$entry" ]] && walk "$entry" $((indent+2)); done
}
# If the path is empty use the current, otherwise convert relative to absolute; Exec walk()
[[ -z "${1}" ]] && ABS_PATH="${PWD}" || pushd "${1}" && ABS_PATH="${PWD}"
walk "${ABS_PATH}"
popd
echo
I expect >./aacToMp3.sh ./music to traverses the music directory and convert each m4a file to .mp3.
It is walking the file system and printing out correct files, with the spaces escaped. When it hits the ffmpeg line it halts. I put the set -e at the top of the file to force it to fail if the command fails. Without the set -e it happily walks all the music files and prints them to the stdout.

Answer 1

If you have lots of files to process and a decent multi-core CPU and fast disk, I would recommend GNU Parallel which you can install with homebrew:
brew install parallel
Then make a copy of a few files in a test directory and try:
parallel --dry-run ffmpeg -v 5 -y -i {} -acodec libmp3lame -ac 2 -b:a 320k {.}.mp3 ::: *.m4a
If that looks good, replace --dry-run with --progress.
If that looks good, you can (make a backup first) and do the whole lot:
find path/to/music -name "*.m4a" -print0 | parallel -0 --progress ffmpeg -v 5 -y -i {} -acodec libmp3lame -ac 2 -b:a 320k {.}.mp3

Answer 2

Thanks for all the input.
After a while I ended up writing all the ffmpeg lines to a script file. Glad I did. I was able to quickly scan the file and see some errors and fix them.
This is what I came up with.
Basically I am writing straight text to stdout and directing it to a file. Which I converted to a shell script to convert each file. One at a time. Ran the generated script overnight.
file_convert() {
ENTRY_FILE=$(printf %q "${entry}")
FILE_NAME=$(printf %q "$(basename "${entry}")")
DIR=$(printf %q "$(dirname "${entry}")")
NAME="${FILE_NAME%.*}"
EXT="${FILE_NAME##*.}"
MP3NAME="${DIR}/${NAME}.mp3"
if [ $EXT == "m4a" ]
then
printf 'echo "Converting %s ..."\n' "$FILE_NAME"
printf 'ffmpeg -v 5 -y -i %s -acodec libmp3lame -ac 2 -b:a 320k %s\n\n' "$ENTRY_FILE" "$MP3NAME"
fi
}
The output looked like.
#!/usr/bin/env bash
echo "Converting 03\ It\'s\ Not\ My\ Time.m4a ..."
ffmpeg -v 5 -y -i /Users/arthuranderson/Documents/work/projects/mp3Convert/music/3\ Doors\ Down/3\ Doors\ Down\ \(Bonus\ Track\ Version\)/03\ It\'s\ Not\ My\ Time.m4a -acodec libmp3lame -ac 2 -b:a 320k /Users/arthuranderson/Documents/work/projects/mp3Convert/music/3\ Doors\ Down/3\ Doors\ Down\ \(Bonus\ Track\ Version\)/03\ It\'s\ Not\ My\ Time.mp3
echo "Converting 01\ Down.m4a ..."
ffmpeg -v 5 -y -i /Users/arthuranderson/Documents/work/projects/mp3Convert/music/311/Greatest\ Hits\ \'93-\'03/01\ Down.m4a -acodec libmp3lame -ac 2 -b:a 320k /Users/arthuranderson/Documents/work/projects/mp3Convert/music/311/Greatest\ Hits\ \'93-\'03/01\ Down.mp3
Mark I will try parallel when I purchase some more music next time.
Thanks everyone!