Quickly re-encodes a video file to .mp4. Add it to your PATH (along with ffmpeg).

reencode.bat

@echo off

IF "%1"=="" (
    echo Usage: reencode path_to_file [optional_crf]
    goto eof
)

SET crf="23"
IF NOT "%2"=="" (
    SET crf=%2
)

REM https://trac.ffmpeg.org/wiki/Encode/H.264
for %%i in (%1) do ffmpeg -i %1 -c:v libx264 -crf %crf% -preset slower -c:a libopus -strict -2 "%%~ni_x264.mp4"

:eof