conv.bat:
ffmpeg -y -i "%1" -ss 10 -to 1000 -vf [in]rotate=0:bilinear=0[middle];[middle]scale=1920:-1[out] -map 0:0 -c:v libx264 -crf 26 ".\conv\%1

conv all.bat:
for /f "tokens=*" %%G in ('dir /b *.mp4') do conv.bat %%G