Linux-audio-dev

linux-audio-dev@lists.linuxaudio.org

7444 discussions

by Andrew Gaydenko

Hi, All! Say, we have such audio-chain: 1. analogue source (say, mic-amp), 2. sound card's line input (let sound card be rme hdsp9632), 3. JackRack (or some other JACKified LADSPA host) with the only LADSPA plugin, let last one be a simple aplifier, 4.1. sound card SPDIF output. 4.2. sound card analogue output, OK, ALSA-driver, HdspMixer, JACK-server and something else are somewhere inside this "user' POV" list. The questions are: - what is full strict list of "audio-entities" steps in such roughly-presented chain? - which formats (float/integer, bitdepth) are used on each step? - which format convertions between steps may be treated as lossless and whcih as "lossness"? And more generally: are there common rules for keeping sound quality intact? I mean only format-related probable issues rather hardware issues like jitter and such. Andrew

17 years, 2 months

2.4 vs 2.6

by arisstotle.52613058＠bloglines.com

I've been working with the 2.6 series kernel now for some time with satisfactory results ie (about 24 msec of latency and solid stability). I chose the 2.6 series because its the latest, and I wouldn't have to patch as much to get support for my hardware (firewire alsa realtime etc...). But I've been reading more and more about how the 2.4 kernels can outperform 2.6 when patched properly, any truth to this?

17 years, 2 months

comments on (sparse) matrix libraries

by Georg Holzmann

Hallo list! I am searching for a sparse matrix library (prefered for C++, otherwise C) for an audio project. However, I found really many libraries and am a little bit confused which one I should take - so I wanted to ask here if someone can give me comments/suggestions to libraries they use ? Many thanks for any comment, LG Georg

17 years, 2 months

[ANN] QjackCtl 0.3.1a (unstable-qt4) crash-fix released!

by Rui Nuno Capela

Hi again, QjackCtl 0.3.1a (unstable-qt4) crash-fix released! This is an emergency crash-fix release and everyone is envited to ditch yesterdays one. The change-log just says it all: - An immediate showstopper crash upon client start was irradicated, which was affecting those with the system-tray icon disabled, as is the default (thanks to Ken Ellinwood for first reporting this sloppy one). Again, the fix source tarball is made available from: http://qjackctl.sourceforge.net http://sourceforge.net/projects/qjackctl Cheers && Enjoy, -- rncbc aka Rui Nuno Capela rncbc(a)rncbc.org

17 years, 2 months

audio conversion functions

by Craig Hoedebeck

I am relatively new to audio programming, but I have a task that requires converting between various audio formats: unsigned 16 bit linear to signed 16 bit linear u_law to signed 16 bit linear a_law to signed 16 bit linear unsigned 8 bit linear to signed 16 bit signed 8 bit linear to signed 16 bit Anyone know what the conversion functions for these would look like? Or even what a good reference is where I can find these? I have been googling around for about an hour and I have come up empty. ____________________________________________________________________________________ Be a better Globetrotter. Get better travel answers from someone who knows. Yahoo! Answers - Check it out. http://answers.yahoo.com/dir/?link=list&sid=396545469

17 years, 2 months

[ANN] QjackCtl 0.3.1 (unstable-qt4) is out!

by Rui Nuno Capela

Greetings y'all, Just one week after a no-regrets migration, here comes this second iteration over the Qt4 framework for the JACK Audio Connection Kit "cutie" GUI front-end that everybody loves or at least ought to :) QjackCtl 0.3.1 (unstable-qt4) is out! The main feature on this release, besides for the bug-fixes, is that it's the very first time ever QjackCtl is made available to build and run on all major desktop platforms: X11/Linux, Windows and Mac OS X. Yes you read it right, Windows, and it is thought to behave consistently on all those. One just have to take advantage from the Qt4 open-source edition and license which in fact is the same as QjackCtl's: GPL2. Yes, there's no turning back. QjackCtl is definitely a Qt4 application, this release marking the departure from the old, aged Qt3 code base, despite this one being tagged as "stable-qt3" anyway. The current branch has "unstable-qt4" on its middle name still, but not for long ;) Being a so-called shallowed bug-fix release, the change-log says some thingies that were shoved out, and nothing about the ones that still are creepin': - The current DSP load percentage activity is now also displayed on the system-tray icon tooltip. - An illusive but nasty Connections/Patchbay item tooltip crash bug has been hopefully fixed (Qt >= 4.3). - Now using QSystemTrayIcon class facility if available (Qt4 >= 4.2) making the system-tray option available on most platforms, notably on Windows and Mac OS X (EXPERIMENTAL). - Usage of QProcess class has been severely refactored, now using QProcess::start() instead of QProcess::startDetached(), giving much tighter control over the started jackd(mp) process. Downside is that QjackCtl lost its ability and option to leave the process detached upon quitting the application. Too bad. - A new eye-candy bit has sneaked in: server mode display, that is the RT indicator, now blinks when server/client is started/active. - Combo-box setup history has been corrected on restore, which was discarding the very initial default (factory) contents. - Now that Qt4 is accessible to open-source Windows appplications, there's some experimental stuff sneaking in for jackdmp support on win32 (http://www.grame.fr/~letz/jackdmp.html). - Connections list items were initially sorted in descending order by default. Fixed. Client items are now naturally sorted, again. As usual, the source tarball might be found here: http://qjackctl.sourceforge.net http://sourceforge.net/projects/qjackctl Cheers && Enjoy, -- rncbc aka Rui Nuno Capela rncbc(a)rncbc.org

17 years, 2 months

again [ot] programming c++ problem (functions adresses)

by Julien Claassen

Hi! Sorry to bother again. But I have the following problem I can't solve. I need to wrap some readline-code in my c++-class. Readline has some function-pointers you can set to a function you wrote yourself. So I did. The sinature of my function ALMOST matches that expected by readline, but it complains about the class part of my signature: my function: char** (Midish_rl::*)(const char*, int, int); Readline expects: char8* (*)(const char*, int, int); I tired writing a wrapper function, but for that I need some object, I just tried: char** wrapper(const char *text, int start, int end) { return my_ui.real_function(text,start,end); } The code is divided between a few files, so I couldn't just a a global object 'my_ui', which was known at all times. Does anyone have an idea how to solve it? Note: I don't want to use any external class-libraries, which might perform the task, because of dependencies. Anyway, there are no standard lib, that do that, not that I'm aware of at least. Kindest regards Julien -------- Music was my first love and it will be my last (John Miles) ======== FIND MY WEB-PROJECT AT: ======== http://ltsb.sourceforge.net the Linux TextBased Studio guide ======= AND MY PERSONAL PAGES AT: ======= http://www.juliencoder.de

17 years, 2 months

[ANN] Qsynth 0.3.1 (unstable-qt4) released!

by Rui Nuno Capela

Greetings, So after the great Qt4 migration, which was almost couple of weeks ago already, here comes the so-called shallowed bug-fix release of this "cutie" FluidSynth GUI: Qsynth 0.3.1 (unstable-qt4) has been released! As said, some bug-fixes have popped in and others are still hidden in the closet. Notable changes were: - Now using QSystemTrayIcon class facility if available (Qt4 >= 4.2) making the system-tray option available on most platforms, notably on Windows and Mac OS X (EXPERIMENTAL). - Combo-box setup history has been corrected on restore, which was discarding the very initial default (factory) contents. - One programming error has been corrected, which was affecting the editable preset combo-boxes usability. - Soundfont context menu is now available again even when the setup dialog soundfont list is empty. - About form link is now browseable externally. - Updated README-OSX (thanks to Ebrahim Mayat again). Grab it while it's hot: http://qsynth.sourceforge.net http://sourceforge.net/projects/qsynth Enjoy && Cheers, -- rncbc aka Rui Nuno Capela rncbc(a)rncbc.org

17 years, 2 months

2.6.20 scheduler and buffer underruns

by Darren Gibbs

We're doing an ARM-based embedded device, which right now is running vanilla 2.6.20. For the sake of simplicity we wrote an OSS driver that's simply double-buffering and writing to the DAC via I2S. We have a buffer underrun problem that is directly proportional to CPU load... no glitches when simply cat-ing a file to /dev/dsp, but lots of glitches when other things are happening on the system. Can anyone suggest tools/techniques/patches for improving the situation? Use an alternative scheduler? Figure out which driver might be turning interrupts off for too long? We're using 20ms buffers which seems pretty generous. I know this is a bit of a noob question, but any advice or pointers to info much appreciated. darren

17 years, 2 months

{OT} kind of some obscure c++-error

by Julien Claassen

Hi everyone! This is not directly linux-audio, but still, I think here are some programmers, who know c++ quite well, bettern than me at least. I wrote some code, I can provide it if necessary and when I compiled it, I finally got this error(s), which I don't understand: In file included from /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/ 4.1.2/ios:47, from /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/ 4.1.2/istream:44, from /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/ 4.1.2/fstream:44, from /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/ 4.1.2/ext/stdio_filebuf.h:39, from rm_midish_rl.cpp:13: /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/localefwd.h :90:35: error: macro "isxdigit" passed 2 arguments, but takes just 1 In file included from /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/ 4.1.2/bits/basic_ios.h:44, from /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/ 4.1.2/ios:50, from /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/ 4.1.2/istream:44, from /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/ 4.1.2/fstream:44, from /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/ 4.1.2/ext/stdio_filebuf.h:39, from rm_midish_rl.cpp:13: /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/locale_face ts.h:4550:45: error: macro "isxdigit" passed 2 arguments, but takes just 1 /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/localefwd.h :90: error: 'std::isxdigit' declared as an 'inline' variable /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/localefwd.h :90: error: template declaration of 'bool std::isxdigit' /usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/locale_face I use g++-4.1.2 on debian etch stable. My code incorporates the following system-headers: iostream, fstream, string, vector, cstdio, cstdlib, cctype, csignal, unistd.h, ext/stdio_filebuf.h, errno.h and the readline headers. I'm not sure wether this is helpful info, but I can't imagine, where this comes from, I don't expect, that the system-libraries are that buggy. :-) Can anyone help me? Kindest regards Julien -------- Music was my first love and it will be my last (John Miles) ======== FIND MY WEB-PROJECT AT: ======== http://ltsb.sourceforge.net the Linux TextBased Studio guide ======= AND MY PERSONAL PAGES AT: ======= http://www.juliencoder.de

17 years, 2 months

Jump to page:

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

Linux-audio-dev