@ECHO OFF
CLS
SET /A _count=0
FOR %%G IN (*.m4a) DO SET /A _count+=1
SET /A _num=1
FOR %%G IN (*.m4a) DO (CALL :SUB_VLC "%%G")
IF NOT EXIST cdda MKDIR cdda
FOR %%G IN (*.m4a.wav*) DO (CALL :SUB_RENAME "%%G")
GOTO :eof

:SUB_VLC
 SET _firstbit=%1
 SET _qt="
 CALL SET _newnm=%%_firstbit:%_qt%=%%
 SET _commanm=%_newnm:,=_COMMA_%
 CALL "C:\Program Files (x86)\VideoLAN\VLC\vlc.exe" --intf dummy %1 --sout=#transcode{acodec="s16l",ab="128",channels="2",samplerate="44100"}:standard{access="file",mux="wav",dst="%_commanm%.wav"} vlc://quit
 ECHO fichier %_num%/%_count% converti
 SET /A _num+=1
GOTO :eof

:SUB_RENAME
 SET _origfnm=%1
 SET _origfpath=%~dp1
 SET _endbit=%_origfnm:*.m4a=%
 CALL SET _newfilenm=%%_origfnm:.m4a%_endbit%=.wav"%%
 CALL SET _newfilenm=%%_newfilenm:%_origfpath%=%%
 SET _newfilenm=%_newfilenm:_COMMA_=,%
 COPY %1 .\cdda\%_newfilenm%
 DEL %1
GOTO :eof

:eof