Re: [Jack-Devel] How to setup jack for transmission of audio from embedded system to jack equipped audio workstation?

hello,

you're close to having it work.

The config on your workstation looks ok, the problem is on the embedded side.

On the embedded system, you have to start jack with the "net" backend, not the alsa one.
jackd -R -d net  (more option available)
Doing this, the embedded system will look for a master jack which is started on the workstation, and create the ports for audio communication.

Then to have the signal of your guitar go through the network link, you have to use jack_load audioadapter on the embedded system to gain access to the soundcard.

A lot more information on this page, will help you understand better this configuration :
http://trac.jackaudio.org/wiki/WalkThrough/User/NetJack2

I have tried a similar setup, and it's working great ! Good luck

Raphaël

Le 26 oct. 2013 à 00:05, Wojciech Zabołotny a écrit :

> Hi,
> 
> I'm preparing a jack based wireless guitar system.
> The previous solution was based on microcontroller,
> dedicated radio link and receiver imitating USB audio card
> ( http://www.ise.pw.edu.pl/~wzab/wireless_guitar_system/ ).
> In this solution I used "alsa_in" to synchronize the input stream
> with the soundcard in the receiving audio workstation.
> 
> Upgrading my system I have decided to replace the microcontroller
> based transmitter with dedicated radion link with an embedded system
> equipped with the WiFi card, and use standard WiFi card as the
> receiver in the audio workstation.
> 
> I have successfully implemented the driver for CS5343/4 ADC for the
> ALSA SoC and packaged the jack2 for Buildroot.
> ( https://groups.google.com/forum/#!topic/comp.sys.raspberry-pi/EgQAQ0DNwN4 ,
>  http://lists.busybox.net/pipermail/buildroot/2013-October/081087.html ),
> so now I only need to integrate jack in the embedded system with jack in the
> workstation.
> 
> And here I run into real problems.
> I'd like to have the audio workstation initialized in such a way, that
> jack is running, audio processing programs are also running and connected
> to jack, and the system waits for connection of the embedded system
> as an audio source.
> So I have started jack with qjackctl on my workstation. Then I should to
> create the audio input ports associated with the network server waiting
> for data stream coming from my embedded system. However I couldn't find
> any way to do it :-(.
> I've tried "jack_load netmanager", but it didn't create any ports.
> Adding the "-c" option didn't help
> (load netmanager -i "-c").
> So I've tried to run "jack netadapter", and it created additional
> capture ports.
> But now it is unclear for me, how to connect to it from my embedded system,
> because it seems, that now my audio workstation should be the slave...
> 
> When I start jack in my embedded system:
> jackd -P41 -p512 -t10000 -dalsa -r48000 -p256 -n2 -Xseq  -Chw:0,0
> jack_load netmanager -i "-c"
> 
> Nothing happens in the workstation. In the jack message window I can still see:
> Ringbuffer automatic adaptative mode size = 1024 frames
> NetAdapter started in sync mode without Master's transport sync.
> Waiting for a master...
> 
> I don't know, is it possible to setup such a system with workstation
> waiting for connection of the embedded system?
> Should I use another protocol - e.g. netone?
> Should I write my own application imitating "alsa_in" but using
> the network connection?
> 
> I'll appreciate any suggestions, explanantions or hints.
> 
> TIA & Regards,
> Wojtek
> 
> 
> 
> 
> "jack_load netmanager" on it.
> 
> 
> Jack-Devel mailing list
> [hidden]
> http://lists.jackaudio.org/listinfo.cgi/jack-devel-jackaudio.org

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