Re: [linux-audio-user] jack -> realtime mastering

From: Andres Cabrera <andres@email-addr-hidden>
Date: Tue Mar 29 2005 - 16:35:53 EEST

Hi Iain,
I am starting to use csound with jack, and it supports multichannel full
duplex with the only limitation that if you use input, -b must be a
multiple of ksmps. I'm using:
csound -b512 -B128 --sched -+rtaudio=jack -iadc:alsa_pcm:caprute_
-odac:alsa_pcm:playback_ -M0 -m0
And it is receiving midi and producing audio without glitches. Needs
some more reliability testing, but it's working.
As for a compressor with visual feedback, the only one I've seen is
jamin, but it might be overkill for your purposes and if you plan to add
jamin to all your tracks you need to run four+ instances (since jamin is
stereo) and that would drown most cpus. Plus there's a problem when
compressing several tracks with independent compression: image shift.
When compressing multichannel signals, the compressors should be linked
so that any reduction in any channel is reflected in the rest of the
channels, otherwise you get image shifting. I don't think there is an
octo-compressor for linux, and there probably isn't one for windows
either (maybe 6 channel). (maybe it can be designed with csound?)
I can't comment on the quality of the compressors, but I guess they are
Ok, and for a live setting more than enough. I would like to hear
opinions on this.
Cheers,
Andres

On Fri, 2005-03-25 at 21:50, Iain Duncan wrote:
> I would like to set up a small mastering rack just before sound output
> for live shows, this is on linux. Essentially I'm hoping to have about
> 8-12 channels of audio go out of csound5 via jack and into some sort of
> host for plugins and mixing down to four channels of final audio out.
> All I want to run are a few compressors and some eq, with easy access to
> the control parameters and graphic vu meters of the compression. Ideally
> these plug ins would also be controllable via midi cc's and some form of
> API so I can make my own gig front end integrated with my csound user
> interface. Questions:
>
> Is this feasable with csound5 now? Has anyone gotten multi-output
> working well with Jack?
>
> What should host the plugins? Ecasound looks promising, but will I be
> able to get graphic vu meters of the compression action? Does that even
> work properly, ie can the screen respond fast enough? Anything else I
> should look into? Jammin seems heavy me thinks.
>
> Which plugins should I use? I'd like minimal cpu use, but a good easy
> over compressor ( soft-knee ), a good final limiter, graphic eq, and
> paramateric eq. Compressor must have accurate controls for attack,
> release, ratio, threshold, and some form of knee control.
>
> Is this even feasable? Are the LADSPA plug-ins good enough now to
> replace hardware in the $300 compressor, $100-200 eq range? I don't
> expect it to sound as good as TL-Audio tubes or anything, but I won't
> drop $300 on an FMR or buy a bunch of ProSonus's if a plugin can sound
> as good as that.
>
> All suggestions welcome, thanks.
> Iain
>
>
Received on Mon Mar 28 20:15:06 2005

This archive was generated by hypermail 2.1.8 : Mon Mar 28 2005 - 20:15:12 EEST