MP4_AAC_M4A

@echo off
setlocal
chcp 65001>nul
if "%1" == "restart" goto :convert
:: Path to ffmpeg and sourcedir
set "ffmpeg=c:\ffmpeg.exe"
set "sourcedir=%~dp0"
set /p "mapfiles=Total mp4 files in each map: "

:: Check if there are mp4-files
if not exist "*.mp4" (
    echo No mp4 files found. Exiting...
    pause
    exit /b
)

:: Initialising variable
set /a mapnum=1

:process
:: Make folders
set "targetdir=%sourcedir%mp4_aac_m4a_%mapnum%"
if not exist "%targetdir%" mkdir "%targetdir%"
if not exist "%targetdir%\aac" mkdir "%targetdir%\aac"
if not exist "%targetdir%\m4a" mkdir "%targetdir%\m4a"

:: Move files to new folder
set /a moved=0
for /f "delims=" %%f in ('dir /b "*.mp4"') do (
    call :moving "%%f"
)
if %errorlevel% equ 5 (call :restart_script)
if not exist "*.mp4" (call :restart_script)
exit

:convert
:: Convert .mp4 to .aac and .m4a
for /l %%g in (1,1,%mapnum%) do (
    for /f "delims=" %%a in ('dir /b "%sourcedir%mp4_aac_m4a_%%g\*.mp4"') do (
        echo Extracting to %%~na.aac
        "%ffmpeg%" -i "%sourcedir%mp4_aac_m4a_%%g\%%a" -vn -sn -c:a aac -b:a 320k "%sourcedir%mp4_aac_m4a_%%g\aac\%%~na.aac" 1>NUL 2>&1
    )
    for /f "delims=" %%a in ('dir /b "%sourcedir%mp4_aac_m4a_%%g\aac\*.aac"') do (
        echo Converting to %%~na.m4a
        "%ffmpeg%" -i "%sourcedir%mp4_aac_m4a_%%g\aac\%%a" -bsf:a aac_adtstoasc -codec copy "%sourcedir%mp4_aac_m4a_%%g\m4a\%%~na.m4a" 1>NUL 2>&1
    )
)
echo All files processed.
pause
exit

:moving
set "file=%~1"
set "escapedfile=%file:&=^&%"
if not exist "%file%" (exit /b 5)
echo Moving... %escapedfile%
move "%file%" "%targetdir%" >nul
set /a moved+=1
if %moved% equ %mapfiles% set /a mapnum+=1 & goto :process
exit /b 5

:restart_script
:: Restarting script...
endlocal
call "%~f0" restart
exit /b