Can I pipe /dev/video over ssh

If you have a low bandwidth I recommend compression of the video stream (still works in 2020).

with ffmpeg and mplayer

ssh USERNAME@REMOTEHOST ffmpeg -an -f video4linux2 -s 640x480 -i /dev/video0 -r 10 -b:v 500k -f matroska - | mplayer - -idle -demuxer matroska

where

• -an turns off audio encoding. If you want audio, replace -an with -f alsa -ac 1 -i hw:3 (where hw:3 could also be hw:0 or hw:1, … See arecord -l for your device). If you want audio only (no video), use this)
• -s 640x480 is the size of your video in x and y dimension
• -r 10 is the framerate you want to receive (lower makes better images at low bitrates, but looks more bumby)
• -b:v 500k is a bitrate of 500 kilobit/s

You need ffmpeg on the remote host and mplayer on the local machine installed.

with ffmpeg and mpv

ssh USERNAME@REMOTEHOST ffmpeg -an -f video4linux2 -s 640x480 -i /dev/video0 -r 10 -b:v 500k -f matroska - | mpv --demuxer=mkv /dev/stdin

with ffmpeg and ffplay

ssh USERNAME@REMOTEHOST ffmpeg -an -f video4linux2 -s 640x480 -i /dev/video0 -r 10 -b:v 500k -f matroska - | ffplay -f matroska /dev/stdin

Something like:

dd if=/dev/video0 | mplayer tv://device=/dev/stdin

works for me (SOA#1) locally. So does:

ssh localhost dd if=/dev/video0 | mplayer tv://device=/dev/stdin

As well as

mkfifo test
dd if=/dev/video0 of=test &
mplayer tv://device=test

Hence:

1. Try without named pipe
2. Check bandwidth

Also - how does in not work (display black screen, complains about unknown device etc.)?

The VideoLAN Project exists in large part to do just what you desire.

I've not used its streaming capabilities but in its single machine use it has shown to be rock solid for me.