Reencode an 45min Ep to 1.4Gb

To re-encode an average 45 minutes TV-Series episode to about 1.4GB (mkv, x264, 720p), use this:

ffmpeg -y -i <infile> -acodec ac3 -scodec copy -s hd720 \
-vcodec libx264 -preset slow -threads 0 -x264opts \
fast_pskip=0 -b:v 4000K  -minrate 4000K \
./out.mkv