audio_to_lp4

@echo off
setlocal enabledelayedexpansion

:: Set the base path of the batch file
set "BASE_DIR=%~dp0"
set "INPUT_DIR=%BASE_DIR%original"
set "OUTPUT_DIR=%BASE_DIR%lp4converted"
set "LOG_FILE=%BASE_DIR%conversion_log.txt"

echo Starting conversion process > "%LOG_FILE%"
echo =========================== >> "%LOG_FILE%"

for /f "usebackq delims=" %%F in (`powershell -NoProfile -Command ^
    "Get-ChildItem -File -Path '%INPUT_DIR%' -Recurse | Where-Object { $_.Extension -match '\.(flac|mp3|ogg|m4a|alac|aac|wav|wma|opus|aiff|ape)$' } | ForEach-Object { $_.FullName }"`) do (
    echo. >> "%LOG_FILE%"
    echo Processing: %%~nxF >> "%LOG_FILE%"
    echo --------------------------- >> "%LOG_FILE%"

    :: Extract metadata using ffprobe JSON
    set "TEMP_JSON=%TEMP%\meta_%%~nF.json"
    ffprobe -v quiet -print_format json -show_format "%%F" > "!TEMP_JSON!"

    :: Parse metadata using PowerShell
    for /f "usebackq delims=" %%a in (`powershell -NoProfile -Command ^
        "(Get-Content -Raw '!TEMP_JSON!' | ConvertFrom-Json).format.tags.artist"`) do set "ARTIST=%%a"
    for /f "usebackq delims=" %%a in (`powershell -NoProfile -Command ^
        "(Get-Content -Raw '!TEMP_JSON!' | ConvertFrom-Json).format.tags.album"`) do set "ALBUM=%%a"
    for /f "usebackq delims=" %%a in (`powershell -NoProfile -Command ^
        "(Get-Content -Raw '!TEMP_JSON!' | ConvertFrom-Json).format.tags.title"`) do set "TITLE=%%a"
    for /f "usebackq delims=" %%a in (`powershell -NoProfile -Command ^
        "(Get-Content -Raw '!TEMP_JSON!' | ConvertFrom-Json).format.tags.track"`) do set "TRACK=%%a"

    :: Extract bit depth using ffprobe
    for /f "usebackq delims=" %%b in (`ffprobe -v quiet -select_streams a:0 -show_entries stream=bits_per_sample -of default=nw=1:nk=1 "%%F"`) do set "BITDEPTH=%%b"

    :: Choose sample format based on bit depth
    if "!BITDEPTH!"=="24" (
        set "SAMPLEFMT=s32"
    ) else (
        set "SAMPLEFMT=s16"
    )

:: Set defaults
if not defined ARTIST set "ARTIST=Unknown_Artist"
if not defined ALBUM set "ALBUM=Unknown_Album"
if not defined TITLE set "TITLE=Unknown_Title"
if not defined TRACK set "TRACK=00"

:: Sanitize metadata
call :SanitizeString ARTIST
call :SanitizeString ALBUM
call :SanitizeString TITLE

    :: Strip "1/13" to just "1"
    for /f "tokens=1 delims=/" %%t in ("!TRACK!") do set "TRACK=%%t"
    if 1!TRACK! LSS 110 set "TRACK=0!TRACK!"

    :: Log metadata
    echo Artist: !ARTIST! >> "%LOG_FILE%"
    echo Album : !ALBUM! >> "%LOG_FILE%"
    echo Title : !TITLE! >> "%LOG_FILE%"
    echo Track : !TRACK! >> "%LOG_FILE%"
    echo BitDepth: !BITDEPTH!  → SampleFmt: !SAMPLEFMT! >> "%LOG_FILE%"

    :: Set final path and filename
    set "TARGET_DIR=%OUTPUT_DIR%\!ARTIST!\!ALBUM!"
    if not exist "!TARGET_DIR!" mkdir "!TARGET_DIR!"
    set "OUTPUT_FILE=!TRACK! - !TITLE!.wav"

    echo Saving to: !TARGET_DIR!\!OUTPUT_FILE! >> "%LOG_FILE%"

    :: Convert to WAV using detected bit depth
    ffmpeg -y -i "%%F" -sample_fmt !SAMPLEFMT! "!TARGET_DIR!\!OUTPUT_FILE!" >> "%LOG_FILE%" 2>&1

    :: Encode to ATRAC3 at 66kbps stereo, save .at3 in same folder as .wav
    set "ATRAC_FILE=!OUTPUT_FILE:.wav=.at3!"
    at3tool.exe -e -br 66 "!TARGET_DIR!\!OUTPUT_FILE!" "!TARGET_DIR!\!ATRAC_FILE!" >> "%LOG_FILE%" 2>&1

    if exist "!TARGET_DIR!\!ATRAC_FILE!" (
        echo Created ATRAC: !TARGET_DIR!\!ATRAC_FILE! >> "%LOG_FILE%"
    ) else (
        echo ERROR: ATRAC not found at !TARGET_DIR!\!ATRAC_FILE! >> "%LOG_FILE%"
    )

    echo Done converting %%~nxF >> "%LOG_FILE%"
    del "!TEMP_JSON!"
)

echo.
echo All files processed. See conversion_log.txt for details.

:: Ask user if WAV files should be deleted
echo.
set /p DELWAV=Delete all converted WAV files? (y/n):
if /i "%DELWAV%"=="y" (
    echo Deleting WAV files...
    for /r "%OUTPUT_DIR%" %%W in (*.wav) do del "%%W"
    echo WAV files deleted.
) else (
    echo Keeping WAV files.
)

:: Ask user if log file should be deleted
echo.
set /p DELLOG=Delete conversion log file? (y/n):
if /i "%DELLOG%"=="y" (
    del "%LOG_FILE%"
    echo Log file deleted.
) else (
    echo Keeping log file.
)

echo.
pause

goto :eof

:SanitizeString
:: Properly sanitize invalid filename characters in the value of a variable
set "varname=%~1"
call set "value=%%%varname%%%"
setlocal enabledelayedexpansion
set "value=!value:^<=_!"
set "value=!value:^>=_!"
set "value=!value::=_!"
set "value=!value:"=_!"
set "value=!value:/=_!"
set "value=!value:\=_!"
set "value=!value:|=_!"
set "value=!value:?=_!"
for /f "tokens=* delims= " %%x in ("!value!") do set "value=%%x"
endlocal & set "%varname%=%value%"
goto :eof