Download youtube music videos or playlist (with static album art) into m4a file with embedded album art. Requires ffmpeg, AtomicParsley, yt-dlp

youtube-audio.sh

#!/bin/bash
if [[ -z "$1" ]]; then
    echo "usage : $0 [YOUTUBE_URL_OR_ID]" >&2
    exit 1
fi
OK=1

ffmpeg >/dev/null 2>/dev/null
if [[ $? -eq 127 ]]; then
    echo "ffmpeg is required : https://ffmpeg.org/download.html" >&2
    OK=0
fi

AtomicParsley >/dev/null 2>/dev/null
if [[ $? -eq 127 ]]; then
    echo "AtomicParsley is required : https://github.com/wez/atomicparsley#installation" >&2
    OK=0
fi
yt-dlp --version >/dev/null 2>/dev/null
if [[ $? -eq 127 ]]; then
    echo "yt-dlp is required : https://github.com/yt-dlp/yt-dlp#installation">&2
    OK=0
fi

jq --version >/dev/null 2>/dev/null
if [[ $? -eq 127 ]]; then
    echo "jq is required : https://stedolan.github.io/jq/download/" >&2
    OK=0
fi



[[ $OK -eq 0 ]] && exit 1

set -e
WD="$PWD"
DIR=""

clean_up() {
    set +e
    ARG=$?
    popd >/dev/null 2>/dev/null
    rm -Rf "$DIR" 2>/dev/null
    exit $ARG
}
trap clean_up EXIT



PLAYLIST="$1"
while [[ ! -z "$PLAYLIST" ]]; do
    echo "==> `tput bold`$PLAYLIST`tput sgr0`" >&2
    URLS=$(yt-dlp --dump-json "$PLAYLIST" | jq -r '.original_url' |  jq -rR --slurp '. | split("\n") | join(" ")' )
    for YOUTUBE in $URLS; do
        echo "==> `tput setaf 2; tput setab 0; tput bold`$YOUTUBE`tput sgr0`" >&2
        DIR=$(mktemp -d)
        pushd "$DIR" >/dev/null

        yt-dlp -f "bestaudio[ext=m4a]" "$YOUTUBE"
        FILES_COUNT=$(ls -1 | wc | awk '{print $1}')
        M4A=$(ls -1 | head -n1)
        if [[ "$FILES_COUNT" -gt 1 ]]; then
            echo "`tput setaf 1; tput setab 0`WARNING: more than one files downloaded. This script can only process one file at a time`tput sgr0`" >&2
            echo "`tput bold`Processing : $M4A`tput sgr0`" >&2
        fi

        echo "==> getting JSON" >2
        JSON=$(yt-dlp --dump-json "$YOUTUBE")

        # album art (first frame)
        echo -e "\r$(tput el)==> setting album metadata"

        VID_TEMP="temp-vid.mp4"
        ART="art.jpg"
        yt-dlp  -f "bestvideo[ext=mp4]" \
            --embed-metadata \
            --output "$VID_TEMP" "$YOUTUBE"
        ffmpeg -loglevel error -i "$VID_TEMP"  -vf "select=eq(n\,0)" -q:v 3  "$ART"
        if [[ $? -ne 0 ]]; then
            echo "==> failed to download art" >&2
            ART=""
        fi
        
        ALBUM="$(echo "$JSON" | jq -r .album)"
        ARTIST="$(echo "$JSON" | jq -r .artist)"
        TITLE="$(echo "$JSON" | jq -r .title)"
        AtomicParsley "$M4A" \
            --artwork "$ART" \
            --artist "$ARTIST" \
            --title "$TITLE" \
            --album "$ALBUM" \
            --comment "$YOUTUBE" \
            --overWrite 
        echo "" >&2
        mv -v "$M4A" "$WD"

        rm -Rf "$DIR"
        popd >/dev/null
    done
    shift    
    PLAYLIST="$1"
done
exit 0