Reduce Matroska video / audio quality before streaming with netcat

Without resolution change:

ffmpeg -i - -b:v 1M -b:a 128k -preset ultrafast -f matroska - | netcat -lp 8123

Downsampling from to 1280×720:

ffmpeg -i - -vf scale=-1:720 -b:v 1M -b:a 128k -preset ultrafast -f matroska - | netcat -lp 8123

Receiving with VLC and netcat:

netcat server.ip 8123 | vlc -