Hi all
As part of a bigger project, I need to develop a module which reads PCM data
from a file and feeds it to sound driver. Is it possible to develop such a
module without actually writing device driver, I mean just by using existing
functions such as snd_pcm_open and all that ? Can someone throw more light
on this ?
Regards,
Avadhoot
hi,
germany uses 'h' in musical scores where most of the rest uses 'b'. Is
that entirely true? Are there other countries that use 'h' as well.
Ideally I look for a table that maps, locales $LANG to h/b.
Stefan
On Thursday 08 November 2007, Nedko Arnaudov wrote:
[...]
> The point is that some plugins need *realtime safe* memory
> allocation.
Well, yes; that part is quite obvious.
What I meant was, if all the host provides is a pool of uniformly
sized chunks that are allocated when the plugin is initialized, there
doesn't seem to be much point in implementing it on the host side.
The naïve host side implementatio would add exactly nothing, compared
to plugins just allocating their own pools during initialization.
A proper real time manager, with arbitrary chunk sizes, would be more
motivated, as it adds functionality that plugins can't implement
internally; namely a shared memory pool.
> I
> need this functionality for lv2zynadd plugin (like arbitrary voices
> count allocation)
The "standard" solution is to pre-allocate and pre-initialize voice
structures for a fixed maximum polyphony.
Obviously, this becomes troublesome with modular synths and the like,
where the "voice structure" doesn't have a fixed size.
One solution is to allocate the voice pool as a response to "program
change" events. Of course, this makes the "programe change" operation
non real time safe, but it usually is anyway, due to samples being
loaded from disk and stuff. Many systems, both hardware and software,
are based entirely on the idea that patch loading is part of
setup/initialization, as that is often the only practical solution.
It's really only entirely ROM based synths (or "small fixed sample
set", in the case of software), virtual analog synths and the like
that *can* implement real time safe "program change" at all.
> and for lv2dynparam plugin library internal
> operation too.
It needs to "regroup" internally as a response to certain parameter
changes?
> There were rumors in #lad that such functionality may be useful
> without lv2dynparam extension.
Well, yes; real time safe dynamic memory management can make life a
lot easier for some types of plugins, and/or reduce memory
requirements by having a shared pool. However, I think it needs to be
more generic than just a pool of fixed size chunks for the "shared
pool" part to be viable.
[...]
> That reminds me that LV2 may need a way to specify optional features
> that interdepend. I.e. features (extensions) A and B are both
> optional but if A is provided B is required. Of course plugin can
> check this explicitly on instantiate and refuse to use feature, but
> I'm not sure how vital is such approach.
Haven't really thought about this... Isn't it just a matter of plugins
and hosts listing *all* extensions? I mean, if you provide or ask for
this feature A, but not feature B, you have a bug. An automatic
validation tool would trap this right away - but of course,
someone/something has to tell the *tool* about these extension
interdependencies...
//David Olofson - Programmer, Composer, Open Source Advocate
.------- http://olofson.net - Games, SDL examples -------.
| http://zeespace.net - 2.5D rendering engine |
| http://audiality.org - Music/audio engine |
| http://eel.olofson.net - Real time scripting |
'-- http://www.reologica.se - Rheology instrumentation --'
e
i'm using cheap Terratec Aureon 5.1 USB MKII and i'm happy that
through jack i can use 3 output channels coz it supports surround... do
you guys know of some PCI sound card (cheap?) which will have more
than 3 output channels?
i would like to build linux sound box as sooperlooper[1] with topot[2]
which i'm (together with marijn[3]) working on works great.. with more
output channels i can separately send loops to external effect
boxes...
thanx
[1] http://essej.net/sooperlooper/
[2] https://savannah.nongnu.org/projects/topot
[3] http://eloquentjavascript.net/
Purpose of this LV2 extension is to standardize realtime safe
allocations in a plugin. Plan is, host to provide functions that plugin
can call. Pointers to functions are provided through host
feature. Only memory pool (fixed chunk size) functionality is
defined.
Attached is early draft of the header. Doxygen generated from it
documentation is available at:
http://svn.gna.org/viewcvs/*checkout*/lv2dynparam/website/doxygen/lv2__rtme…
Any comments are welcome. In particular about whether general purpose
allocator (arbitrary memory chunk size) should be part of this same
extension.
--
Nedko Arnaudov <GnuPG KeyID: DE1716B0>
I am proud to announce that AlsaPlayer-0.99.80 got stable, thanks to the hard
work of every one that contributed to the GTK2 interface and other functions,
as well that by submitting/fixing bugs.
This release is a bug fixes release.
See the ChangeLog for the details: http://www.alsaplayer.org/changelog.php3
Every user is encouraged to upgrade:
http://sourceforge.net/project/showfiles.php?group_id=249
If you want to help by submitting bugs or contributing artwork and code, look
at the website: http://www.alsaplayer.org/main.php3
Ciao,
Dominique
Given a sample clip, I would like to be able to find in another audio file a
part that sounds similar to the clip. So for example, given a cymbal sample,
I would like to be able to find a part of an audio file that sounds similar
to a cymbal. I am not interested in beat detection, but rather just getting
a single slice.
Having only a basic grasp of digital audio theory I am wondering what
algorithms would be applicable for this situation. I am also new to Linux
audio, so I would appreciate any pointers to libraries that provide this
functionality or means to implement it myself.
