Re: [Jack-Devel] Connecting alsa-loopback to jack
Le Wed, 18 Jul 2012 01:37:56 -0700 (PDT),
James Warden <[hidden]> a écrit :
> Hi there,
>
> A shame my WIKI page disappeared.
After the disappearance, I wrote something plus or minus similar, and
in my bad English, into the gentoo pro-audio overlay's wiki:
http://proaudio.tuxfamily.org/wiki/index.php?title=DAW_Digital_Audio_Workstation#Using_an_ALSA_Loopback_device_and_JACK_alsa_in.2Falsa_out_clients
The text explanation is shorter than what you wrote, but hopefully, the
code for the configuration must be very similar.
Dominique
> I believe that Mark Constable was
> the maintainer of the unofficial ALSA WIKI site. IIRC, he told me
> some time ago that he could eventually drop the site. I hope there is
> some sort of backup because I took some time a while back to update
> it with more optimization tricks.
>
> Mark, if you read this, could you give the list a clue as to what
> happened to your WIKI site ?
>
> Thanks.
>
> J.
>
>
>
> ________________________________
> From: aCOSwt <[hidden]>
> To: [hidden]
> Sent: Wednesday, July 18, 2012 9:49 AM
> Subject: Re: [Jack-Devel] Connecting alsa-loopback to jack
>
> This is my asound.conf inspired from some thread in LinuxMusicians :
>
> ==========================================
> [note 1 : The following line is not compulsory for the redirection to
> work ] defaults.pcm.rate_converter "samplerate_best"
>
> [note 2 : Alsa default is to be concerned because many jack-unaware
> packages output on the sole Alsa Default. (Adobe-Flash being an
> example) ]
>
> pcm.!default{
> type plug
> slave.pcm "aduplex"
> hint{
> show on
> description "Alsa Default"}}
>
> pcm.aduplex{
> type asym
> playback.pcm "amix"
> capture.pcm "asnoop"}
>
> pcm.amix{
> type dmix
> ipc_key 219345
> slave{
> pcm "hw:Loopback,0,0"
> format S32_LE
>
> [note 3 : You absolutely want to adjust the three following values
> according to your # Jack instance sampling rate and tests you'll have
> completed on your system.]
>
> period_size 512
> buffer_size 16384
> rate 44100}}
>
> pcm.asnoop{
> type dsnoop
> ipc_key 219346
> slave.pcm "hw:Loopback,0,1"}
>
> pcm.ploop{
> type plug
> slave.pcm "hw:Loopback,1,1"}
>
> pcm.cloop{
> type dsnoop
> ipc_key 219348
> slave{
> pcm "hw:Loopback,1,0"
> format S32_LE
>
> [note : idem note 3]
>
> period_size 2048
> buffer_size 8192
> rate 44100}}
>
> [note 4 : Of course, you will adapt the values given as ipc_key to
> your system. I mean, choosing values that won't ever be used by other
> programs you run. ]
> =========================================
> In addition to this, you must create jack permanent clients => create
> a script named for example Loop2Jack :
>
>
> /usr/bin/alsa_out -j ploop -dploop -q 1 2>&1 1> /dev/null &
> /usr/bin/alsa_in -j cloop -dcloop -q 1 2>&1 1> /dev/null &
> sleep 1
> jack_connect cloop:capture_1 system:playback_1
> jack_connect cloop:capture_2 system:playback_2
> jack_connect system:capture_1 ploop:playback_1
> jack_connect system:capture_1 ploop:playback_2
> exit 0
> ==========================================
> You'll then ensure that this script is executed after jackd's startup.
> Launch it manually or, if you use qjackctl there is an option field
> for allowing this as part of the setup/options page.
>
> Having (I hope so) helped you to do what you wish, I must tell that
> having used this facility myself, I came to realize that I was
> nothing but stupid. As a matter of fact, I think we can state that
> nowadays, the applications not jack-aware are consumer grade
> applications playing medias of relatively poor audio quality.
> You will have additionally noticed that the dmix plugin was used in
> the asound.conf with a rather huge buffer that will have the
> consequence to add some significant latency.
> Why then, would you want to bother you real-time-low-latency sound
> server with this sort of sound ?
> Because your jackd might almost probably be "wired" to your best
> quality sound device, why would you want <=22Khz samples from your
> speech-synth, Skype, DE's sound notifier... to be driven to this
> device ? Worse ! Why would you want these sounds of somehow random
> occurrence to spuriously pollute your precious 24bits >=96KHz
> recording ?
>
> OK then, of course this is nothing but an opinion from my personal
> experience. I only suggest you wonder before bothering too much.
>
> Regards,
>
> aCOSwt
>
> Jack-Devel mailing list
> [hidden]
> http://lists.jackaudio.org/listinfo.cgi/jack-devel-jackaudio.org
--
"We have the heroes we deserve."
1342625055.24952_0.ltw:2,a <20120718181948.2bf0fbcd at tuxstudio>