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

given that netjack1 and alsa_in were written by the same person, you might
want to consider that fact for a few minutes.


On Sun, Oct 27, 2013 at 2:53 PM, Wojciech Zabolotny <[hidden]>wrote:

> Yes, indeed, I have got it running, but in fact i'm not fully
> satisfied with achieved latency.
> In fact I thinkthere may be a need for a dedicated solution, due to
> following requirements:
>
> 1. It is supposed to be a wireless guitar system, so the embedded system
> must
>    be connected via WiFi.
>  2. UDP over WiFi will almost for sure result in lost packets (due to
> collisions),
>     so I need a protocol with acknowledge (RUDP, UDP-RT or simply TCP/IP?)
> 3. At the transmitter side there is no need for buffering at all. I
> should simply
>     transmit all samples received from the ALSA driver as quickly as they
> come.
>     The buffering and synchronization should be done only on a receiver
> side.
>
> So I think, that the best way to go will be to modify the existing
> alsa_in program so that it receives samples via network...
>
> Thanks & Regards,
>
> Wojtek
>
> On Sat, Oct 26, 2013 at 11:29 AM, raf <[hidden]> wrote:
> > 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
> >
> 
> Jack-Devel mailing list
> [hidden]
> http://lists.jackaudio.org/listinfo.cgi/jack-devel-jackaudio.org
>

1382903574.28693_0.ltw:2, <CAFa_cKkUU6qn6HH3y2K91xtQKTL=vjx+pxJ0enORoOdyzMUhgw at mail dot gmail dot com>