Free tool:
::
:: God's Audio Injector
::
@echo off
setlocal EnableExtensions DisableDelayedExpansion
if "%~2"=="" (
echo Usage: sound AUDIO VIDEO
echo.
echo Example:
echo sound sound.m4a video.mp4
exit /b 2
)
where ffmpeg.exe >nul 2>&1
if errorlevel 1 (
echo ERROR: ffmpeg.exe was not found in PATH.
exit /b 127
)
if not exist "%~2" (
echo ERROR: Video file not found:
echo %~2
exit /b 2
)
if not exist "%~1" (
echo ERROR: Sound file not found:
echo %~1
exit /b 2
)
ffmpeg.exe ^
-i "%~2" ^
-i "%~1" ^
-map 0:v:0 ^
-map 1:a:0 ^
-map_metadata -1 ^
-c:v copy ^
-c:a aac ^
-movflags +faststart ^
"%~dpn1_new.mp4"
exit /b %ERRORLEVEL%
