Linux-audio-dev

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7516 discussions

by Fons Adriaensen

Hello all, The first release of jkmeter is now available in the usual place: <www.kokkizinita.net/linuxaudio/downloads> Also updates of japa and jnoise (mostly maintenance, but see also below). >From the README: jkmeter-0.1.0 (03/08/2008) -------------------------- Jkmeter is a horizontal or vertical bargraph level meter based on the ideas of mastering guru Bob Katz. See <http://www.digido.com/bob-katz/index.php> and follow the links on 'level practices'. This is the type of meter you want for live recording, mixing and mastering. It probably makes no sense to use it on all tracks of a DAW, where keeping digital level within limits is the main purpose of metering. This release implements the K-20 meter. Future releases will include the K-14 meter as well. A K-meter displays both the true RMS level and the digital peak level. The ballistics as defined by Bob Katz are somewhat ambiguous. In this implementation the RMS meter is about 15% faster than an VU, but without the overshoot. This provides a good indication of subjective loudness. Instead of providing extra gain for the RMS level, the K-meter displays it on the same scale as the digital peak level, but puts the '0dB' mark and the color change well below the OdB full scale level. For the K-20 meter it is 20dB down, for the K-14 this is (surprise !) 14 dB. To use the meter as envisaged by Bob Katz, you should have a fixed monitoring level, adjusted so that pink noise indicating 0dB on the meter corresponds to 83 dB(C) (from each speaker) as indicated by an sound level meter. Note the (C) - not (A) - weighting. As of release 0.4.0, both japa and jnoise provide a pink noise source at exactly this level. The current release does not include the 22kHz lowpass filter required for frequencies such as 96kHz and higher. Enjoy ! -- FA Laboratorio di Acustica ed Elettroacustica Parma, Italia O tu, che porte, correndo si ? E guerra e morte !

17 years, 3 months

[ANN] a2jmidid version 3 "Bodrum" released

by Nedko Arnaudov

a2jmidid is a project that aims to ease usage of legacy ALSA sequencer applications, in a JACK MIDI enabled system. a2jmidid implementation is based on jack-alsamidi-0.5 that is [almost] same as jackd ALSA "seq" MIDI backend, both created by Dmitry Baikov. Static bridges are based on code by Sean Bolton and Lars Luthman. Homepage with screenshots: http://home.gna.org/a2jmidid/ Tarball download: http://download.gna.org/a2jmidid/ Changes since version 2: * Improved port naming, support for bidirectional ports * Allow exporting of hardware ports (disabled by default) * Switch from autotools to waf * Remove support for old JACK MIDI API variants * Remove usage of posix semaphores that could cause sleep in realtime context, in rare circumstances * D-Bus background service mode. The old manual mode is still working. * Log file when running in background service mode. * Improved documentation * Import, with slight modifications, static bridges created by Sean Bolton and Lars Luthman. -- Nedko Arnaudov <GnuPG KeyID: DE1716B0>

17 years, 3 months

Re: [LAD] Car engine sound emulation for future electic cars. ideas

by Kjetil S. Matheussen

Fons Adriaensen: > > The data used by car manufacturers to describe engine noise > is a spectral description, where some small divider of the > RPM (depending on engine configuration) is regarded as the > funcdamental frequency. For each harmonic you have a smooth > amplitude map in function of RPM and throttle position. > > Staring from these it's not so difficult to synthesise > something quite realistic. > The company "Staccato" tried to provide synthesized car sounds for race car games in 1999, according to this page: http://www.scandalis.com/Jarrah/PhysicalModels/index.html

17 years, 3 months

Re: [LAD] embedded high end audio

by Pieter Palmers

Florian Faber wrote: > Peter, > >> I doubt that it is easy over a transport protocol that doesn't have a >> global absolute time reference (like ethernet). > > What time reference do you have in mind on ethernet that can be used as > word clock source? My formulation is a bit unfortunate. I mean that ethernet does NOT have a global absolute time reference. And word clock is not a time reference. It's a 'rate' reference, which does not contain absolute time information. What you need to output signals on different devices with sample accurate phase is an absolute time reference. Which ethernet does not have. Greets, Pieter

17 years, 3 months

Ladspa: Text encoding for metadata fields

by David García Garzón

I have some doubts, as both host and plugin programmer, regarding the text encoding that should be used for Ladspa v1 metadata fields. Is there any convention? Utf8? Is it limited to plain ASCII? Which fields are restricted and which are not? I supose that unicode is supported in some way as many 'makers' have weird signs on their name but the header-documentation does not provide any answer to that. David García Garzón.

17 years, 3 months

[ANN] Realtime priority patch for the linux kernel, jack_capture V0.9.23 and Rollendurcmesserzeitsammler V0.0.4

by Kjetil S. Matheussen

Download from: http://old.notam02.no/arkiv/src/?M=D Realtime priority patch for the linux kernel ============================================ To make sure the Linux kernel is able to grant realtime priority, and full nice and mlock capabailites can still be a little bit inconvenient and/or frustrating. However, this super-tiny patch: http://old.notam02.no/arkiv/src/realtime.diff against the linux source shortcuts all other methods. No more pam, realtime-lsm, rtlimits etc. jack_capture ============ jack_capture is a program for recording soundfiles with jack. Its default operation is to capture whatever sound is going out to your speakers into a file. (But it can do a number of other operations as well...) Changes 0.9.19 -> 0.9.23: *Minor spellings *Check for out of memory *Clean up source a bit *Stop connection thread before closing jack client. *Made --help a tiny bit cleaner *Removed shut down code from the SIGINT signal handler. *Fixed segfault in case jack shuts down. Thanks to Julien Claassen for reporting the bug. (Note that there is also a 0.9.24 release. 0.9.24 has changed internal data representation from lockless ringbuffer to lockless lifo and fifo stacks. (Unmodified lifo/fifo code taken from midishare. (Copyright Grame 1999-2005)) 0.9.24 probably works fine, but it shouldn't be used for important recordings since it hasn't been much tested yet.) Rollendurchmesserzeitsammler v0.0.5 ------------------------------------ The Audio Rollendurchmesserzeitsammler is a conservative garbage collector especially made for running inside an audio DSP thread. New about this release is that I have finally replaced TLSF (http://rtportal.upv.es/rtmalloc/) with a pool-based dynamic memory allocator, which makes allocation using the rollendurchmesserzeitsammler approximately as fast as using custom memory pools. Using the rollendurchmesserzeitsammler should be a lot more convenient than memory pools though, and since memory is not freed manually, but instead is automatically freed in a separate thread, there is a slight chance that using rollendurchmesserzeitsammler instead of custom memory pools could make some DSP code run faster. In non-synthetic benchmarks, I have not been able to see any significant improvement in CPU use because of this compared to using the TLSF allocator. But for programs doing millions of allocations per second, the new memory allocator will probably perform significantly better than TLSF, if it would ever make sense doing so many and frequent allocations of course... Changes 0.0.4 -> 0.0.5 * Implemented a custom pool-based dynamic memory allocater. This new memory allocator is now set as default. To use TLSF instead, set "USE_TLSF=-DUSE_TLSF" in the Makefile before compiling. The following changes are caused by this switch: * Allocating memory is now approx 10 times faster (13 vs. 168 instructions for the allocation itself, but there are some GC overhead too) * The allocator copies used memory only (not just the whole heap). But not always! This was a lot more complicated to to with TLSF so I didn't do that. Note that for the garbage collector to still be hard realtime safe, the programs must ensure that full copies are taken now and then. (There's a change in the API for doing that) * Doing a garbage collection is much faster since the heaps are usually much smaller (because only used memory is copied) and that freeing is 10-20 times faster. * Further improvements for reducing memory overhead and make searching for used mem to be O(log n) instead of O(n) is much simpler now. (this is TODO though) * However 1: In case the code using the garbage collector will continue forever to allocate memory of different sizes, the new dynamic memory allocator could eventually run out of memory even if the program itself doesn't use very much memory. I don't think this is very likely to happen for DSP routines though, and there might even be solutions to fix this problem if it should ever come up. For now, just switching to TLSF fixes the problem. * However 2: in non-synthetic benchmarks, I have not been able to see any practical improvement in CPU use, apart from the slight improvement in CPU available for use in non-realtime threads because taking snapshots usually takes a lot less time now. But for programs doing millions of allocations per second, the new memory allocator will probably perform significantly better than TLSF, if it would ever make sense doing so many allocations of course.

17 years, 3 months

Re: [LAD] [OT] vector drawing software

by Kjetil S. Matheussen

Fons Adriaensen: > > Inkscape lookd more and more as some GUI interface > to Cairo. ATM I can write the Cairo code a lot > faster than using the GUI... > I was just about to suggest writing Cairo code. :-) pgf/tikz is probably faster than programming cairo though. But what would be really nice would be a programming interface for pgf/tikz.

17 years, 3 months

Re: [LAD] [OT] vector drawing software

by Kjetil S. Matheussen

Fons Adriaensen: > > Anyone knows a good vector drawing program for Linux ? > > Absolute requirements are: > > - Lines, arrows, boxes, circles, etc. > - Linewidths and styles, colors, filling. > - Text > - PDF or PS export. > - PNG and JPEG import (no bitmap editing required). > - Accuracy. > > I've been using TGIF for years, but I'm more and > more being blocked by its main flaw which is that > it seems to use a unit of 0.2mm internally (in > metric mode) which is orders of magnitude too big. > > Tried QCAD and INKSCAPE, both fail basic > requirements (and have other problems). > > Maybe pgf / tikz would be useful? http://www.ctan.org/tex-archive/help/Catalogue/entries/pgf.html

17 years, 3 months

jack, kernel, etc. versions & priorities

by Garett Shulman

Hello, I had a great performing linux audio setup until I had to move to a newer kernel to get some hardware on a new motherboard to work. Now I can't seem to get decent performance and thought it might be helpful if folks could chime in with what versions, etc. they are using with decent success. In particular I'm having a very challenging time with Linux Sampler, which I had previously working very solidly but now regardless of numerous jack/ls version permutations segfaults when I create a jack driver in ls. Thanks! -Garett Kernel version? RT patch? Preemption mode? Audio hardware IRQ scheduling policy and priority? Alsa version if different from kernel? Jack version, scheduling policy and priority? Linux Sampler version (or cvs date), scheduling policy and priority?

17 years, 3 months

need some C++ help

by Dave Phillips

Greetings, I'm compiling a program called kodisein, an open-source VJ tool. I'm hitting the wall here: g++ -c -w -I /usr/include/stlport -I ../lib/handler -I ../lib/tools -I ../lib/types -I ../lib/values -I ../lib/widgets -I ../lib/windows -I ../src -I ../src/connectors -I ../src/handles -I ../src/objects -I ../src/modules -I ../src/modules/attribute -I ../src/modules/matrix -I ../src/modules/object -I ../src/modules/value -I /usr/include/SDL -I /usr/include/GL -o ../lib/handler/KEventHandler.o ../lib/handler/KEventHandler.cpp ../lib/handler/KKeyActionHandler.h:42: error: expected initializer before ‘<’ token ../lib/handler/KKeyActionHandler.h:51: error: ‘KeyActionHash’ does not name a type make: *** [../lib/handler/KEventHandler.o] Error 1 The file in question is short enough to include at the end of this message (line 42 is at the typedef). I have minimal skill debugging C++ and have no idea how to fix this problem. Any suggestions from the C++ masters here ? TIA, dp /* * KKeyActionHandler.h * kodisein */ #ifndef __KKeyActionHandler #define __KKeyActionHandler #include "KKeyHandler.h" #include "KConsole.h" #include <ext/hash_map> using namespace std; // -------------------------------------------------------------------------------------------------------- class KKeyAction : public KNotificationObject { protected: string key_name; public: KKeyAction ( const string & keyName ) : KNotificationObject () { key_name = keyName; } virtual ~KKeyAction () {} virtual const string & getKeyName () const { return key_name; } }; // -------------------------------------------------------------------------------------------------------- struct eqstr { bool operator()(const char* s1, const char* s2) const { return strcmp(s1, s2) == 0; } }; typedef hash_map <const char*, KKeyAction *, hash <const char*>, eqstr> KeyActionHash; // -------------------------------------------------------------------------------------------------------- class KKeyActionHandler : public KKeyHandler { INTROSPECTION protected: KeyActionHash key_handlers; string last_key; public: KKeyActionHandler () : KKeyHandler () {} virtual ~KKeyActionHandler (); KKeyAction * getActionForSequence ( const string &, bool = false ); bool addSequenceCallback ( const string, KObject *, KCallbackPtr ); bool setSequenceCallback ( const string, KObject *, KCallbackPtr ); void removeSequenceCallback ( const string, KObject *, KCallbackPtr ); bool isSaveSequenceCallback ( const string & ); bool handleKey ( const KKey & ); }; #endif

17 years, 3 months

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Linux-audio-dev