SSH Audio transmission

[Redemption]

http://mattkaar.com/blog/2012/12/01/ras ... y-monitor/

Hi, i'm doing a project similiar to a baby monitor require a Raspberry pi to transmit audio from a USB mic to another device. I was following the instruction on the website stated.

Setting up a ssh connection with putty for windows.

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$ arecord -D plughw:1,0 -f dat | ssh -C user@192.168.1.21 aplay -f dat 

While i was able to remotely control certain features of RPI with putty from my windows PC. I am still unable to transmit any audio/ sound over using the command suggested. It indicates that the user refused connection. What does it mean? Any way to solve it?

[jojopi]

That command is for sending audio between two Linux machines. The "arecord" part runs on one computer, and turns the audio into a binary stream, "|ssh" pipes the data to the other computer, where "aplay" sends it to the sound card.

[Redemption]

Ok. That explains a lot. I shall try that with two raspberry Pi.

[Redemption]

Hi, i have a problem again, i set up ssh connection with two raspberry pi, through a router.

However, when i type the

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arecord -D plughw:1,0 -f dat | ssh -C user@192.168.1.13 aplay -f dat

This will result in

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pi@raspberrypi ~ $ arecord -D plughw:1,0 -f dat | ssh -C user@192.168.1.13 aplay -f datRecording WAVE 'stdin' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
The authenticity of host '192.168.1.13 (192.168.1.13)' can't be established.
ECDSA key fingerprint is 53:3c:bb:47:6f:f1:f5:b9:4d:22:7a:c6:fb:c0:81:c6.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.1.13' (ECDSA) to the list of known hosts.
user@192.168.1.13's password: 
Permission denied, please try again.
user@192.168.1.13's password: 
Permission denied, please try again.
user@192.168.1.13's password: 
Permission denied (publickey,password).

what's the user@192.168.1.13's password? I have no idea what it could be. I don't remember setting any password for it. Anyone know it?

[tonyhughes]

Its a valid username and password for the machine in question.

If it's running Raspbian, its "pi" and "raspberry".

If you changed it, it's whatever you changed it to.

[Redemption]

yes. both the raspberry pi is working on raspbian wheezy.

I've tried both "pi" and "raspberry", I've not changed it either.
Neither of them work ;(

I'm on a dead end .

[tonyhughes]

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arecord -D plughw:1,0 -f dat | ssh -C user@192.168.1.13 aplay -f dat

The line above... paste the actual line you are typing, with no modifications...

[Redemption]

Oh..that's the actual line i type with no modifications.

[tonyhughes]

Do you have a user on that device with that actual system username of "user"?

Should be "pi" or "john" or "sally" or something.

[Redemption]

Just double checking.

I've no user on the RPI itself, using the default login id as "pi" and "raspberry" as password for Raspbian OS. So i should be typing this instead?

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arecord -D plughw:1,0 -f dat | ssh -C pi@192.168.1.13 aplay -f dat

[tonyhughes]

Definitley yes.

If you have only got the "pi" user, then you must use that.

Literally typing "user" as a username simply won't work.

If your Pi is exposed to the internet at all (via DMZ or port forwarding) you MUST change the password for the "pi" account.

You can do this by running

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sudo raspi-config

on your Pi.

[Redemption]

Hi, i've tried the code.

[code]arecord -D plughw:1,0 -f dat | ssh -C pi@198.168.1.13 aplay -f dat [/code]

It still does not work. Instead, another problem arises.
[code] pi@raspberrypi ~ $ arecord -D plughw:1,0 -f dat | ssh -C pi@192.168.1.13 aplay -f dat
ALSA lib pcm_hw.c:1401:(_snd_pcm_hw_open) Invalid value for card
arecord: main:682: audio open error: No such file or directory
pi@192.168.1.13's password:
aplay: playback:2483: read error[/code]

What does this mean? Have i set up the system wrongly?

Let me list down the method i use to set up SSH between my two RPI.

First i enable the SSH server on pi with

[code]pi@raspberrypi ~ $ sudo raspi-config
update-rc.d: using dependency based boot sequencing
insserv: warning: script 'S17resize2fs_once' missing LSB tags and overrides
insserv: warning: script 'resize2fs_once' missing LSB tags and overrides
[ ok ] Starting OpenBSD Secure Shell server: sshd.[/code]

then i connect it with

[code]pi@raspberrypi ~ $ ssh 192.168.1.13[/code]

and it indicates that it is successful with

[code]pi@192.168.1.13's password:
Linux raspberrypi 3.2.27+ #250 PREEMPT Thu Oct 18 19:03:02 BST 2012 armv6l

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Thu Feb 21 17:20:25 2013[/code]

Have i done it wrongly?

[toku]

It looks like you've got the SSH part working now. I think the issue you're having now is the -D argument you're passing to arecord.

Run this command on the pi you're trying to record from to list the available devices:

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arecord -l

You should see output like this:

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$ arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: GoMic [Samson GoMic], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

I think you take the card number (1 here) and the device number (0 here) for the arecord -D option. Based on my output above, I'm maknig this work with this command:

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arecord -D plughw:1,0 -f dat | ssh -C pi@raspberrypi aplay -D plughw:0,3 -f dat

Note that I also specified a device on the aplay side. You may need to determine your aplay device using the same method (inspect the output of aplay -l on the pi you're going to use to play).

[seyoung]

I succeeded doing it from Ubuntu with the following command:

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ssh pi@192.168.1.13 arecord -c 2 -f S16_LE -d 300 -r 44100 | aplay -f S16_LE

Note: I have attached an Wolfson soundcard but you can change the parameters as you wish.

[fruitoftheloom]

I succeeded doing it from Ubuntu with the following command:

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ssh pi@192.168.1.13 arecord -c 2 -f S16_LE -d 300 -r 44100 | aplay -f S16_LE

Note: I have attached an Wolfson soundcard but you can change the parameters as you wish.

You do realise the post you are replying to is nigh on 2 years old