8

I want to attach an analog camera to an old linux computer and directly pipe the /dev/video0 to another computer, where I can use it as a device again (so /dev/video0 should go to /dev/remote0, for example)

(Reason for doing this is that the computer does not have enough power to encode the video)

Is that possible? I've seen people can pipe the data directly from the device over ssh into mplayer, but I need to have some sort of reference point for Zoneminder.

  • Edit: As Phil Hannent said: SSH would probably also be too resource intensive for the hardware as it has to encrypt the data it sends. So is this also possible over a program like tcptunnel?

  • Edit2: On the Unix & Linux stackexchange site I found a question that uses this for piping over ssh: ssh localhost dd if=/dev/video0 | mplayer tv://device=/dev/stdin can that be done over tcptunnel?

Improve this question

3 Answers 3

Reset to default
6

You can use netcat.

cat /dev/video0 | nc -l 1234

This will open a server on one host listening on port 1234 and sending uncompressed and unencrypted data from /dev/video0 to any client that connects. You can receive the data on other host by invoking:

nc videohost 1234 | mplayer tv://device=/dev/stdin

where videohost is the host sending data from /dev/video0.

Improve this answer
7
  • Nice! Is it possible to pipe the data into a /dev/file first, and then separately opening it in mplayer?
    – Jelle De Loecker
    Aug 12, 2011 at 11:25
  • 2
    I'd also like to point out ipusb: it probably works even better than this. It lets you mount a usb device over the network.
    – Jelle De Loecker
    Sep 7, 2011 at 21:51
  • 1
    "nc videohost 1234 | mplayer tv://device=/dev/stdin" output error "Playing tv://device=/dev/stdin. The filename option must be an integer: dev/stdin Struct tv, field filename parsing error: dev/stdin". I think this problem in my webcam or in my mplayer. "nc videohost 1234 | vlc - " work for me.
    – user3439968
    Feb 22, 2016 at 20:24
  • 4
    Tried this - cat: /dev/video0: Invalid argument
    – Code Wiget
    Dec 7, 2018 at 19:43
  • 1
    @Ryan, try netcat (see stackoverflow.com/questions/15534994/…)
    – Paweł Nadolski
    Dec 8, 2018 at 6:56
4

The netcat solution didn't work for me. It either shows a pipe error, or cat reporting Invalid input.

This is the only solution that worked for me:

ssh user@host "ffmpeg  -r 14 -s 640x480 -f video4linux2 -i /dev/video0 -f matroska -" | mplayer - -idle

This has the benefit of it being encoded, so you save bandwidth as a bonus.

Combine with tee and you can watch and record at the same time:

ssh user@host "ffmpeg  -r 14 -s 640x480 -f video4linux2 -i /dev/video0 -f matroska -" | tee $(date +%Y-%m-%d_%H-%M-%S)_recording.mkv | mplayer - -idle

This will open mplayer for live streaming and save it to a file containing the current datetime at the same time (example filename: 2018-11-22_01-22-10_recording.mkv).

Replace -f matroska with -f avi to use the more compressed avi format. This will save a lot of CPU resources on the source and a lot of bandwidth for a more lag free experience.

Improve this answer
2

I would seriously advise you against this. I recently tried streaming avi videos over an ssh:// file access and its painful. You have to remember that the video is being encrypted and then decrypted during this process.

If your computer cannot handle compressing the stream then it certainly will not be able to handle encrypting it.

Really you want to just have a tcp tunnel the raw data:

http://www.vakuumverpackt.de/tcptunnel/

Improve this answer
1
  • 1
    Right, I forgot about that. But how would you pipe device data over this?
    – Jelle De Loecker
    Aug 11, 2011 at 9:31

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .