@Echo off
SETLOCAL
REM script for adding metadata and art to m4a
REM SCRIPT WILL NOT RUN IF ANY OF THE METADATA FILES ARE EMPTY
rem mainly using MP3 ID3v2 tags
rem date not year https://wiki.multimedia.cx/index.php/FFmpeg_Metadata
rem author is a quicktime tag
for %%f in (*.m4a) do (
for %%M in ([AlbumArtist] [artist] [composer] [Comment] [GENRE] [URLauthor] [year]) do (
echo %%M 
if NOT exist ".\%%~nf %%~M.txt" copy NUL ".\%%~nf %%~M.txt"
)
FOR /f "tokens=* delims=," %%A in ('type "%%~nf [AlbumArtist].txt"') do (
FOR /f "tokens=* delims=," %%a in ('type "%%~nf [artist].txt"') do (
FOR /f "tokens=* delims=," %%c in ('type "%%~nf [composer].txt"') do (
FOR /f "tokens=* delims=," %%C in ('type "%%~nf [Comment].txt"') do (
FOR /f "tokens=* delims=," %%G in ('type "%%~nf [GENRE].txt"') do (
FOR /f "tokens=* delims=," %%U in ('type "%%~nf [URLauthor].txt"') do (
FOR /f "tokens=* delims=," %%y in ('type "%%~nf [year].txt"') do (
ffmpeg -i "%%~nf.m4a" -i "%%~nf.png" -map 0 -map 1 -c copy -disposition:v:0 attached_pic -metadata title="%%~nf" -metadata composer="%%c" -metadata artist="%%a" -metadata author="%%u" -metadata album_artist="%%A" -metadata genre="%%G" -metadata comment="%%C" -metadata author_url="%%U" -id3v2_version 3 -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (front)" -metadata date=%%y "%%~nf(metacoded).m4a"
)
)
)
)
)
)
)
)