Is there any problem with the list(s) server(s)? The last message that I
received is from friday, but I see in the archive web page that there
was more since that day.
The same seems to happens in LAU.
Natanael.
Hi,
When I'm programming, I find it immensely helpful to be able to plot audio
data at different points in its processing, for debugging, and to test new
ideas.
Essentially I want an oscilloscope, which plots each chunk of 1024 samples.
I've tried using libplot, but it seems too slow. It's causing constant
xruns, even when I only plot every 5th sample.
I thought that maybe libplot was too abstract, and that I needed to draw the
pixels on the screen directly. I tried using SDL, but it caused excessive
xruns also. Simply setting 48000 pixels per second was enough to cause the
flow of xruns. This is *not* erasing the screen, just drawing the points.
I'd expect that erasing the screen is the slow part, but apparently not.
At this point I'm not sure if it's even possible to plot the audio data in
realtime. I did a rough calculation, that on my 2 Ghz cpu, it should have
roughly 40,000 cycles to process each sample. It seems to me that
considering running the whole plugin only uses 1/4 of my cpu, the other
30000 cycles should be plenty to put a pixel on the screen.
So I would guess that something else is the bottleneck, like my video chip,
or maybe the libraries I'm using.
So basically my question is: Has anyone else had any luck with plotting
audio data in real time, and if so, how? Is it not possible to plot every
sample, but only a certain percentage of them? Is there a fundamental
restriction on doing so, or is my problem in software?
Jeremy
Jnoisemeter-0.1.0
This is a small Jack/GUI app which you can use to measure
noise levels to various standards, e.g to check the S/N,
EIN or equivalent noise levels of soundcards, mic preamps
and microphones.
Filters: DC, Flat, 20kHz, A, C, ITU-R468, ITU-A.
Detectors: ITU-R468, RMS, VU.
More technical info in the README.
As usual on <http://www.kokkinizita.net/linuxaudio/downloads>
Enjoy !
--
FA
O tu, che porte, correndo si ?
E guerra e morte !
On Thu, 17 Jun 2010 23:44:28 +0400
Louigi Verona <louigi.verona(a)gmail.com> wrote:
> Hello Simon!
> I am interested - how do you achieve phasing on Linux? Using what tools?
>
> --
> Louigi Verona
> http://www.louigiverona.ru
>
Check this out.. you will need python and numpy.
Simon.
Hi all,
So I'm banging around some piano samples:
http://pythonicle.net/sounds/output-7.ogghttp://pythonicle.net/sounds/output-7.mp3
using phasing (a la Steve Reich) and some piano samples I found here:
http://www.pianosounds.com/freesoundfont.htm
Does anyone have a recommendation for a more comprehensive (non-free even)
piano sound palette ?
I use python code* and was very happy to be able to import soundfont files.
I see also these gigasampler files, maybe i can use libgig to access those (?)
*Here are all my secrets: http://pythonicle.net/svn/projects/dsptools
Take a look if you are curious. There is python wrappers for using numpy
with ladspa and portaudio. And i forget what else. One of these days
I might get around to cleaning all this up, but right now I need to
make sounds just to bring some sanity into my world.
bye for now,
Simon.
Hi,
Is it common experience when (design/code/test module repeat) a real
time audio or (as in my case) MIDI application, that, as soon as you
finally solve a problem that's been bugging you for ages, and take a
step forward, you immediately step upon another whopping great pile of
@#$!???
It's taken me at least four months so far to get as far as I have with
my app. There is still not a single MIDI message emitted from it yet.
It has a GTK GUI with almost as much as 0.01% of the features the GUI
will eventually require.
I've been pretty obsessed with it, spending a high percentage of my
spare time attempting to code this.
Incidentally, if I want the GUI to update very close to real time, say
a grid of blocks flashing on and off as notes come and go, any
thoughts? Would a GTK GUI update fast enough? I'm also wondering about
going for an "Immediate Mode" GUI using SDL, possibly with OpenGL, I'm
unsure... It's a way off yet, I'm concentrating on getting the engine
working without a UI first.
Cheers,
James.
Hi everyone,
a question for one of your OSC gurus out there: is it possible/a good
idea to use OSC for syncing? How good is it for that kind of thing?
So far I have only used it for parameter control, but is there a good
means of using it with timing accuracy?
Thanks a lot
Victor
Another stupid question induced by an argument regarding to MIDI jitter
by Daniel James.
> [snip] I'm sceptical that
> the realtime kernel is the cause of your MIDI problems. If they got this
> right in the 80's, on computers which could not do anything near
> realtime audio processing, then I think it's more likely to be a
> question of MIDI application design.
IMO it's a good hint.
Why do people (not only me) report jitter for external MIDI equipment,
but I couldn't find any report for real-time audio jitter? Resp. what's
about async and disconnecting clients by JACK? Does this regard to the
same issue, caused by the hardware combination?
And it's not only for Linux, but for e.g. Windows Cubase too, while
Cubase on the Atari is ok. OTOH on Windows audio clients don't
disconnect, just MIDI jitter is an issue too.
Cheers!
Ralf
Qjackctl has the -n option to select a Jack server name,
and recent versions also allow multiple presets.
What would it take to make the server name a element of
a preset rather than a command line option ?
That would finally allow to run multiple jacks on the
same machine (something I've been doing quite a lot
recently) without having to start each qjackctl with
a different command line option (e.g. from a desktop
menu).
And maybe the four start/stop scripts should also be
'per preset'.
While we're here: almost no apps support selecting a
specific Jack server. I've been adding this to some
of my own just because I needed it.
Using -n for this can be problematic if the toolset
used doesn't allow context-sensitive options: -n is
also used as a parameter for an ALSA interface, and
some apps support both Jack and ALSA.
Ciao,
--
FA
O tu, che porte, correndo si ?
E guerra e morte !
I thought very long, that it don't support JACK. But I just ran ldd, and saw a dependency on libjack.so.0. And if I try to playback when jackd is not runing, it says, that could not connect to jack server. If server is runing, it doesn't produce any signals, but silently prefers alsa. I have JACK2 and tried both with jackdbus and legacy jackd. So, what is situation?
I assume, it is undocumented and half-complete feature, but it is interesting, to have an expert opinion. I could not find any helpful information about.
