Hi, Anyone knows how can I use callback builtin functions to
operations like capture, playback and events using ALSA API?
For a while I'd implemented calls to callback functions in each return
of 'writei' and 'readi'.
Thank you.
Hi,
Why not solve this kinds of problems.
Soulutions:
1) Remove OSS drivers from kernel - then all problems will be alsa
problems.
2) Remove OSS emulation from alsa - then all problems will be OSS
problems.
Otherways this will be newer end.
Peter Zubaj
___________________________________________________________________________
Podte na navstevu k Wande - k najlepsej priatelke kazdej zeny na internete.
http://www.wanda.sk/
by Kjetil Svalastog Matheussen <k.s.matheussenï¼ notam02.no>
Erik de Castro Lopo:
>
> Kjetil Svalastog Matheussen wrote:
>
>> I was primarily testing speed, but both libraries where using the sinc
>> routine, so...
>
> Yes, but you can design a sinc filter with 10 coefficients and one
> with 10000. The one with 10000 coefficients will have a steeper
> transition band and a better signal to noise ratio.
>
Yes. But back to the point, I think there is an extremely good chance that
mus_src (even by setting the width-argument to 5 (default value is 10
which is also faster than SRC_SINC_FASTEST)) will sound better than whats
being produced by a linear resampler, and might be exactly be what the
person asking the question is looking for.
Lee Revell wrote:
> On Fri, 2005-06-10 at 11:12 -0700, Ian wrote:
> > Can anyone tell me *very briefly* what is the current
> > state of play regarding realtime-lsm in the 2.6.*
> > kernels and whether this feature (or something like it
> > ) is likely to be introduced into the kernel anytime
> > soon.
>
> realtime-lsm should be considered deprecated. The solution accepted by
> Linus is rlimit based. I think this will be in 2.6.12 (seems to be in
> the release candidates). Check the archives for "rlimit".
>
> This will require patching PAM and bash.
In the interim you could try set_rtlimit:
http://www.physics.adelaide.edu.au/~jwoithe/set_rtlimits-1.1.0.tgz
It allows you to access the enhanced rlimits (ie: RT scheduling and nice
levels) under 2.6.12 kernel or later without needing to patch anything. In
fact, even once PAM/etc are patched this might be preferred by some since it
allows you to control the limits based on the program being run; so for
example you can allow /usr/local/bin/ardour to run at realtime priority 50
while /usr/bin/yes (for example) can't.
Regards
jonathan
Erik de Castro Lopo:
> >
> > I recently did a lot of benchmarking between libsamplerate and mus_src
> > in clm/sndlib. My result was quite interesting, the fastest mus_src sinc
> > resampler where a lot faster than the fastest libsamplerate resampler.
>
> I think most people would agree that speed is not the most important
> aspect when measuring the quality of a sample rate converter.
>
I was primarily testing speed, but both libraries where using the sinc
routine, so...
> With libsamplerate, I can state that the three sinc based converters
> have the following characteristics:
>
> SNR Bandwidth
> SRC_SINC_FASTEST 102.42 dB 80.23 %
> SRC_SINC_MEDIUM_QUALITY 98.99 dB 90.68 %
> SRC_SINC_BEST_QUALITY 97.43 dB 96.96%
>
> where SNR is signal to noise ratio and Bandwidth its a percentage of
> the theoretical best bandwidth (ie half of the minimum of the source
> and desination sample rate).
>
> > A third program is the original sinc-resampler from Julius Smith:
> > http://ccrma-www.stanford.edu/~jos/resample/
> > I don't know how this one performs compaired to the other two though.
>
> libsamplerate the same algorithm as this one. I think Julius O. Smith
> developed this algorithm.
>
He did, and Bil Schottstaedt used this algorithm as well for mus_src.
When I compaired mus_src with width=5, and libsamplerate with
SRC_SINC_FASTEST, the first one is much faster, I don't know what kind of
SNR/Bandwidth you get with your way of measuring when using mus_src with
width=5, but the source is easy to read so I guess you can figure it out.
--
Dave Chapman:
>
> The most common case will be downsampling 48KHz->44.1KHz, but there are
> also users who need upsampling from various lower frequencies (e.g. for
> use with audio books).
>
> So we're looking for pointers to any high quality (but fast!) resampling
> code that could be used.
I recently did a lot of benchmarking between libsamplerate and mus_src
in clm/sndlib. My result was quite interesting, the fastest mus_src sinc
resampler where a lot faster than the fastest libsamplerate resampler.
I don't have the results available right now, but I remember that mus_src
performance wasn't very far from beating the linear resampler in
libsamplerate.
I did a lot of test with various types of data and compiler-options, so I
don't think it was a coinsidence. However, it might have been because
of some optimalization gcc was doing or something to do with the
cache. The mus_src code is far smaller and easier to read than the one
for libsamplerate.
I did not hear any difference in soundquality, but I guess there might be
a difference.
Sndlib:
http://ccrma.stanford.edu/software/snd/snd/sndlib.html
mus_src is available in the file clm.c .
libsamplerate:
http://www.mega-nerd.com/SRC/
A third program is the original sinc-resampler from Julius Smith:
http://ccrma-www.stanford.edu/~jos/resample/
I don't know how this one performs compaired to the other two though.
--
hi all,
i'm currently working on a rather large project which i'd like to
fully support under Linux .. it requires, however, a functioning MIDI
sub-system. for this reason, i'd like to ask members of LAD to
report on their experiences with using professional MIDI interfaces,
such as (for example) the Motu MTP AV, Digidesign MIDEX-8, etc?
what is the 'easiest' MIDI interface to get working under the average
Linux kernel? what sort of experiences do folks have with getting
MIDI working (on a programming level) using API's such as (but not
limited to) ALSA, and MidiShare?
for me so far, MidiShare seems to offer the most direct and usable
approach .. while ALSA is wraught with complexity and dependencies
which often seem out of control. i'd like to know what your
experience, as developers, has been with getting a working MIDI
subsystem under Linux ...
--
;
Jay Vaughan
QjackCtl 0.2.16 is finally out!
After laying around for a long time in the backyard (aka CVS:), the Qt
front-end to the one-of-a-kind JACK audio server daemon is finally made
public. Rejoyce!
As one can read from the changelog:
- ALSA sequencer client/port name changes are now properly detected on the
MIDI connections widget (as noted by Chris Cannam. Thanks).
- Long overdue transport buttons (rewind, backward and forward) finally
landed onto the main control window, at last :).
- Duplication (copy) of patchbay socket items was added.
- Do not ever try to start the JACK server if there's one already found
running, on which case the client-only mode of operation is then activated
(as kindly suggested by Orm Finnendahl, thanks).
- After several Mac OS X user requests, ALSA/MIDI sequencer support is now
an option, otherwise detected at configure time and conditionally compiled
in if, and only if, ALSA is found available (which has been a primordial
assumption on Linux systems:). Ah, and that just makes for the blind
inclusion of another backend driver option: coreaudio.
- Actual OSS device selection menu now featured on setup dialog; these
adds to the device selection button menus for the OSS driver settings.
- Delayed geometry setup of windows upon startup was added as an optional
workaround to subtle problems due to window decoration information not
being available at window creation time on some window managers (as patch
proposed by Dirk Jagdmann. Thanks).
- Fixed some minor but rather old bug that was quitting the application
abruptly, when one switches off the system tray icon while the main
application widget is hidden.
- Cancel is now an option when creating a new patchbay definition.
- Context menus are finally littered with icons.
- Minor configure and Makefile install fixes, as Debian and Mac OS X
specialties. Also, install does the right thing with target file modes
(thanks to Matt Flax and Ebrahim Mayat, for pointing these out).
You can get away with it from the usual place:
http://qjackctl.sourceforge.net/http://sourceforge.net/projects/qjackctl
Enjoy!
--
rncbc aka Rui Nuno Capela
rncbc(a)rncbc.org
QjackCtl 0.2.16 is finally out!
After laying around for a long time in the backyard (aka CVS:), the Qt
front-end to the one-of-a-kind JACK audio server daemon is finally made
public. Rejoyce!
As one can read from the changelog:
- ALSA sequencer client/port name changes are now properly detected on the
MIDI connections widget (as noted by Chris Cannam. Thanks).
- Long overdue transport buttons (rewind, backward and forward) finally
landed onto the main control window, at last :).
- Duplication (copy) of patchbay socket items was added.
- Do not ever try to start the JACK server if there's one already found
running, on which case the client-only mode of operation is then activated
(as kindly suggested by Orm Finnendahl, thanks).
- After several Mac OS X user requests, ALSA/MIDI sequencer support is now
an option, otherwise detected at configure time and conditionally compiled
in if, and only if, ALSA is found available (which has been a primordial
assumption on Linux systems:). Ah, and that just makes for the blind
inclusion of another backend driver option: coreaudio.
- Actual OSS device selection menu now featured on setup dialog; these
adds to the device selection button menus for the OSS driver settings.
- Delayed geometry setup of windows upon startup was added as an optional
workaround to subtle problems due to window decoration information not
being available at window creation time on some window managers (as patch
proposed by Dirk Jagdmann. Thanks).
- Fixed some minor but rather old bug that was quitting the application
abruptly, when one switches off the system tray icon while the main
application widget is hidden.
- Cancel is now an option when creating a new patchbay definition.
- Context menus are finally littered with icons.
- Minor configure and Makefile install fixes, as Debian and Mac OS X
specialties. Also, install does the right thing with target file modes
(thanks to Matt Flax and Ebrahim Mayat, for pointing these out).
You can get away with it from the usual place:
http://qjackctl.sourceforge.net/http://sourceforge.net/projects/qjackctl
Enjoy!
--
rncbc aka Rui Nuno Capela
rncbc(a)rncbc.org
Greetings:
It has not been a good week.
As I mentioned yesterday I swapped my hardware into an identical box
as my original machine. Yesterday everything seemed to have returned to
normal operation. I watched some movies, worked on some music, and so forth.
Today I powered up the box, logged on to the net, downloaded the
latest Csound CVS and started compiling. After a few minutes everything
froze again, the machine was locked tight as a drum. I had to pull the
plug to restart, but when grub came up my keyboard was frozen. I pulled
the plug again and got my keyboard back after restarting.
Now I'm running memtest again. I realized yesterday that I'd run it on
only one RAM stick so I thought I'd better check again. However, at this
point I'm starting to suspect a bad drive. But *two* bad drives in the
system ?? As I mentioned in an earlier message, the machine failure
occurred regardless of which drive I was using (RH9 on /dev/hdb, FC3 on
/dev/hda).
So I'm bummed again. Looks like it's time to bite the bullet and buy a
whole new system. :(
Best,
dp