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

Thanks a lot. So before trying to write something myself, I'll try to
repeat my tests using netone instead of netmanager, as soon, as I have
some free time.


On Sun, Oct 27, 2013 at 8:52 PM, Paul Davis <[hidden]> wrote:
> 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
>
>

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