📱 MKV → HEVC Batch Encoder for Smartphone

winget install Gyan.FFmpeg

ffmpeg -version

  Select your GPU / encoder:

    1. AMD      (hevc_amf   - VCE hardware)
    2. NVIDIA   (hevc_nvenc - NVENC hardware)
    3. Intel    (hevc_qsv   - Quick Sync hardware)
    4. Software (libx265    - slow but universal)

@echo off
setlocal enabledelayedexpansion

:: ============================================================
::  Universal MKV → HEVC 8-bit MP4 Batch Encoder
::  Supports: AMD VCE, NVIDIA NVENC, Intel QSV, Software (x265)
::  Audio:     First Japanese track only → AAC 128kbps stereo
::  Subtitles: Burned in with fallback priority:
::               1. English-tagged (eng)
::               2. Default-flagged subtitle in MKV
::               3. First available subtitle track
::               4. Skip file if no subtitles exist
::  Aspect:    4:3 source → 960x720 / 16:9 source → 1280x720
::  Chapters:  Preserved
::  Metadata:  Title set from filename
::
::  IMPORTANT: Run by double-clicking in Explorer or via cmd.exe
::             Do NOT run from PowerShell.
::
::  Requirements: ffmpeg + ffprobe must be in PATH
:: ============================================================

:: --- SETTINGS -----------------------------------------------

set QP=31
set AUDIO_BITRATE=128k
set OUTPUT_DIR=encoded_output
set SHARPEN=3:3:0.3

:: -------------------------------------------------------

:: ================================================================
:: GPU SELECTION MENU
:: Equivalent quality settings across encoders matching CQP 31:
::   AMD    — hevc_amf,   -rc cqp       qp 31
::   NVIDIA — hevc_nvenc, -rc constqp   qp 31
::   Intel  — hevc_qsv,   -q 31         (ICQ mode)
::   x265   — libx265,    -crf 22       (CRF 22 ≈ CQP 31 for HEVC)
:: ================================================================

echo ============================================================
echo  Universal HEVC 8-bit Encoder
echo  QP=31  Audio=128kbps  4:3=960x720  16:9=1280x720
echo ============================================================
echo.
echo  Select your GPU / encoder:
echo.
echo    1. AMD      ^(hevc_amf   - VCE hardware^)
echo    2. NVIDIA   ^(hevc_nvenc - NVENC hardware^)
echo    3. Intel    ^(hevc_qsv   - Quick Sync hardware^)
echo    4. Software ^(libx265    - slow but universal^)
echo.
set /p GPU_CHOICE="  Enter choice (1-4): "

if "%GPU_CHOICE%" == "1" (
    set ENCODER=hevc_amf
    set ENC_LABEL=AMD VCE
    set ENC_PARAMS=-rc cqp -qp_i %QP% -qp_p %QP% -qp_b %QP% -quality quality -profile:v main -pix_fmt yuv420p
)
if "%GPU_CHOICE%" == "2" (
    set ENCODER=hevc_nvenc
    set ENC_LABEL=NVIDIA NVENC
    set ENC_PARAMS=-rc constqp -qp %QP% -preset p4 -profile:v main -pix_fmt yuv420p
)
if "%GPU_CHOICE%" == "3" (
    set ENCODER=hevc_qsv
    set ENC_LABEL=Intel Quick Sync
    set ENC_PARAMS=-q %QP% -preset slower -profile:v main -pix_fmt nv12
)
if "%GPU_CHOICE%" == "4" (
    set ENCODER=libx265
    set ENC_LABEL=Software x265
    set ENC_PARAMS=-crf 22 -preset slow -profile:v main -pix_fmt yuv420p
)

if not defined ENCODER (
    echo.
    echo  Invalid choice. Please enter 1, 2, 3 or 4.
    pause
    exit /b 1
)

echo.
echo  Using encoder: %ENC_LABEL% ^(%ENCODER%^)
echo  Output folder: %OUTPUT_DIR%
echo ============================================================
echo.

if not exist "%OUTPUT_DIR%" mkdir "%OUTPUT_DIR%"

set TMPFILE=%TEMP%\ffprobe_tmp.txt

set ENCODED=0
set FAILED=0
set SKIPPED=0

for %%F in (*.mkv) do (
    echo -------------------------------------------------------
    echo [%%F] Analysing streams...

    :: ================================================================
    :: SUBTITLE SELECTION — three-tier fallback
    :: ================================================================
    set SUB_INDEX=
    set SUB_METHOD=
    set SUB_REL_COUNTER=0

    ffprobe -v error -select_streams s -show_entries stream=index,disposition=default:stream_tags=language -of csv=p=0 "%%F" > "%TMPFILE%" 2>&1

    :: ---- Tier 1: English-tagged subtitle ----
    for /f "usebackq delims=" %%S in ("%TMPFILE%") do (
        if not defined SUB_INDEX (
            set LINE=%%S
            echo !LINE! | findstr /i ",eng" >nul 2>&1
            if !errorlevel! == 0 (
                set SUB_INDEX=!SUB_REL_COUNTER!
                set SUB_METHOD=English-tagged
            )
            set /a SUB_REL_COUNTER+=1
        ) else (
            set /a SUB_REL_COUNTER+=1
        )
    )

    :: ---- Tier 2: Default-flagged subtitle ----
    if not defined SUB_INDEX (
        set SUB_REL_COUNTER=0
        for /f "usebackq delims=" %%S in ("%TMPFILE%") do (
            if not defined SUB_INDEX (
                set LINE=%%S
                echo !LINE! | findstr /r ",1," >nul 2>&1
                if !errorlevel! == 0 (
                    set SUB_INDEX=!SUB_REL_COUNTER!
                    set SUB_METHOD=default-flagged
                )
            )
            set /a SUB_REL_COUNTER+=1
        )
    )

    :: ---- Tier 3: First available subtitle ----
    if not defined SUB_INDEX (
        for /f "usebackq delims=" %%S in ("%TMPFILE%") do (
            if not defined SUB_INDEX (
                set SUB_INDEX=0
                set SUB_METHOD=first available
            )
        )
    )

    :: ================================================================
    :: All remaining processing in if/else — no goto inside loop
    :: ================================================================
    if not defined SUB_INDEX (
        echo [%%F] WARNING: No subtitle tracks found. Skipping file.
        set /a SKIPPED+=1
    ) else (
        echo [%%F] Subtitle selected: index !SUB_INDEX! ^(!SUB_METHOD!^)

        :: ================================================================
        :: RESOLUTION — 4:3 → 960x720, 16:9 → 1280x720
        :: ================================================================
        set STORED_W=
        set STORED_H=
        set SAR_N=1
        set SAR_D=1

        ffprobe -v error -select_streams v:0 -show_entries stream=width -of default=nw=1:nk=1 "%%F" > "%TMPFILE%" 2>&1
        for /f "usebackq tokens=1" %%V in ("%TMPFILE%") do if not defined STORED_W set STORED_W=%%V

        ffprobe -v error -select_streams v:0 -show_entries stream=height -of default=nw=1:nk=1 "%%F" > "%TMPFILE%" 2>&1
        for /f "usebackq tokens=1" %%V in ("%TMPFILE%") do if not defined STORED_H set STORED_H=%%V

        ffprobe -v error -select_streams v:0 -show_entries stream=sample_aspect_ratio -of default=nw=1:nk=1 "%%F" > "%TMPFILE%" 2>&1
        for /f "usebackq tokens=1,2 delims=:" %%A in ("%TMPFILE%") do (
            if not "%%A" == "N/A" if not "%%A" == "0" (
                set SAR_N=%%A
                set SAR_D=%%B
            )
        )

        if "!SAR_D!" == "0" set SAR_D=1
        if "!SAR_N!" == "0" set SAR_N=1

        set /a DISP_W=!STORED_W! * !SAR_N! / !SAR_D!

        set SCALE_FILTER=scale=1280:720:flags=lanczos
        set RES_LABEL=1280x720 ^(16:9 default^)

        if defined DISP_W if defined STORED_H (
            set /a RATIO10=!DISP_W! * 10 / !STORED_H!
            if !RATIO10! GEQ 14 (
                set SCALE_FILTER=scale=1280:720:flags=lanczos
                set RES_LABEL=1280x720 ^(16:9^)
            ) else (
                set SCALE_FILTER=scale=960:720:flags=lanczos
                set RES_LABEL=960x720 ^(4:3^)
            )
        )

        echo [%%F] Display: !DISP_W!x!STORED_H! -^> !RES_LABEL!

        :: ================================================================
        :: JAPANESE AUDIO — find first/default jpn track, map by index
        :: ================================================================
        set JPN_ABS=
        set JPN_REL=0
        set JPN_FOUND=

        ffprobe -v error -select_streams a -show_entries stream=index,disposition=default:stream_tags=language -of csv=p=0 "%%F" > "%TMPFILE%" 2>&1

        :: First pass: default-flagged jpn audio
        for /f "usebackq delims=" %%S in ("%TMPFILE%") do (
            if not defined JPN_ABS (
                set LINE=%%S
                echo !LINE! | findstr /i "jpn" >nul 2>&1
                if !errorlevel! == 0 (
                    echo !LINE! | findstr /r ",1" >nul 2>&1
                    if !errorlevel! == 0 (
                        for /f "tokens=1 delims=," %%I in ("!LINE!") do set JPN_ABS=%%I
                    )
                )
            )
        )

        :: Second pass: first jpn audio track
        if not defined JPN_ABS (
            for /f "usebackq delims=" %%S in ("%TMPFILE%") do (
                if not defined JPN_ABS (
                    set LINE=%%S
                    echo !LINE! | findstr /i "jpn" >nul 2>&1
                    if !errorlevel! == 0 (
                        for /f "tokens=1 delims=," %%I in ("!LINE!") do set JPN_ABS=%%I
                    )
                )
            )
        )

        :: Convert absolute index to audio-relative index
        if defined JPN_ABS (
            set JPN_REL=0
            ffprobe -v error -select_streams a -show_entries stream=index -of csv=p=0 "%%F" > "%TMPFILE%" 2>&1
            for /f "usebackq delims=" %%S in ("%TMPFILE%") do (
                if not defined JPN_FOUND (
                    for /f "tokens=1 delims=," %%I in ("%%S") do (
                        if %%I == !JPN_ABS! (
                            set JPN_FOUND=1
                        ) else if not defined JPN_FOUND (
                            set /a JPN_REL+=1
                        )
                    )
                )
            )
            echo [%%F] Japanese audio: stream !JPN_ABS! ^(audio index !JPN_REL!^)
            set JPN_MAP=0:a:!JPN_REL!
        ) else (
            echo [%%F] WARNING: No Japanese audio found, using first audio track.
            set JPN_MAP=0:a:0
        )

        :: ================================================================
        :: ENCODE
        :: ================================================================
        set TITLE=%%~nF
        echo [%%F] Starting encode ^(%ENC_LABEL%^)...

        ffmpeg -y ^
            -i "%%F" ^
            -vf "!SCALE_FILTER!,subtitles='%%F':si=!SUB_INDEX!,unsharp=%SHARPEN%" ^
            -c:v %ENCODER% ^
            %ENC_PARAMS% ^
            -tag:v hvc1 ^
            -movflags +faststart ^
            -c:a aac ^
            -b:a %AUDIO_BITRATE% ^
            -ac 2 ^
            -map 0:v:0 ^
            -map !JPN_MAP! ^
            -map_chapters 0 ^
            -metadata title="!TITLE!" ^
            "%OUTPUT_DIR%\%%~nF.mp4"

        if !errorlevel! == 0 (
            echo [%%F] Done ^> %OUTPUT_DIR%\%%~nF.mp4
            set /a ENCODED+=1
        ) else (
            echo [%%F] FAILED - check output above for errors
            set /a FAILED+=1
        )
    )

    set JPN_ABS=
    set JPN_FOUND=
    set STORED_W=
    set STORED_H=
    set SAR_N=1
    set SAR_D=1
    echo.
)

if exist "%TMPFILE%" del "%TMPFILE%"

echo ============================================================
echo  Finished!  Encoder: %ENC_LABEL%
echo  Encoded: %ENCODED%   Failed: %FAILED%   Skipped: %SKIPPED%
echo ============================================================
pause