Linux-audio-dev July 2008

linux-audio-dev@lists.linuxaudio.org

61 participants
31 discussions

by Darren Landrum

I've been looking around for a library to read and write SFZ files, which is an open sampler format released by Cakewalk: http://www.cakewalk.com/DevXchange/sfz.asp Finding none, I thought I might try my hand at writing a library for this myself, as there is no embedded wave information like with Gig files. SFZ is simply a text file to be parsed. Now, I know about writing a good header file, and its associated class, and all that, but I have no knowledge of how to write it as a dynamic library. Google searches on every possible permutation have been worthless to me as well. I would prefer to write it in C++, as that's what I know, and even then, not too well, hence why I thought I'd start with something simple like parsing a text file. If anyone has any advice, recommendations, or ideas, I'll happily listen and learn. I have yet to think too much about how the data will be stored in the class, and what methods to make available to access it, so if anyone knows any best practices there, I'd really like to know. Consider this a feeler post. I'd ultimately want this for a future project, which you can guess at by now. Thank you for the help! Regards, Darren Landrum

16 years, 11 months

[OT] vector drawing software

by 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). Ciao, -- FA Laboratorio di Acustica ed Elettroacustica Parma, Italia O tu, che porte, correndo si ? E guerra e morte !

16 years, 11 months

embedded high end audio

by porl sheean

hi there everyone. i hope this is the right list for this, but i just had a question about embedded hardware. if i was wanting to develop a small (up to around 20cm square) device using an embedded linux setup, is there any high end (pro quality jack compatible) audio devices that are easily attainable? basically something like a high end adc/dac for minipci or something similar i suppose. anyone on here know? thanks porl ps. should this be posted to the users list instead, since i suppose it doesn't have a direct connection to linux development?

16 years, 12 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

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

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

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

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

Re: [LAD] [OT] CD-R masters, block error rate and dvd-r mystery...

by Joern Nettingsmeier

hi anthony! thanks for your reply. i'm cc:ing the list so that others can benefit from it as well... Anthony Kozar wrote: > Hi Joern, > > This is just a shot in the dark, but most audio CD tracks have a "lead-in" > time of 2 or more seconds. CD players will typically count down using > negative numbers for this time and the track is considered to begin after > the lead-in. Perhaps one of your drives (the DVD drive?) is reading the > lead-in as part of the track? > > (2 seconds x 44100 samples/sec. x 2 channels x 2 bytes/sample = 352,000 > bytes) i can rule this out, because although i used both a dvdr and cdr drive for burning, both cds were read back in using the cdr drive. any differences must have occured during burning. but since i used the same toc file and disk-at-once mode, it's unlikely that the lead-in got interpreted differently in both drives... but you are right, this being a live cd, i used pre-gaps and non-silent gaps extensively - i'll investigate some more along those lines. best, jörn -- jörn nettingsmeier home://germany/45128 essen/lortzingstr. 11/ http://spunk.dnsalias.org phone://+49/201/491621 Kurt is up in Heaven now.

17 years

Towards a truely realtime capable FOSS audio distribution | A guide to the Jack Source Code

by micu

Hello everybody, my name is micu and I study computer science at the Dresden University of Technology. During an internship at the operating systems chair of the university, I ported ALSA to the chairs operating system DROPS aka TUD:OS [1,2]. To let ALSA talk to the hardware and provide to it the usual linux kernel environment DDEKit / DDELinux [3] were used. As a kernel-userland interface I wrote a very small emulation layer, which makes it possible to link SALSA-lib [4] against the ALSA "kernel" part. So right now, we have a somewhat stable ALSA server running in userland on top of DROPS without changing ALSA or the SALSA-lib source code. I have been continuing this project within my diploma thesis. The remit of the thesis can be found here [5]. It is the goal of the thesis to take some steps towards a truly realtime capable (meaning with time constraints to be guaranteed) FOSS audio distribution. Here [6] you can see a raw version of my requirements definition. The architecture we are going to use is --- how could it be different :) --- Jack or Jackdmp (with a strong bias towards Jackdmp). To get the mess out of my head, I wrote a short guide [7] to the Jack source code. It is a pretty raw version and it isn't finished in any way yet; but I won't work on it any longer. Nevertheless, it might be helpful to other developers new to Jack. Therefore, if you will, you may get it under any license you wish (attribution of the author is appreciated :) to publish and improve it. Of course, the long term goal of the project won't be met to any extent during my thesis and I have no idea, if this project will be continued here at the university. Neither do I know, whether I will have time to work on it afterwards. To make a long story short: I would like to ask my first three questions.... so far :) 1.) Do you agree on having a truly real-time capable architecture in the FOSS audio world would be a really great thing --- and would you say, getting such a thing maybe could get a (major) goal of the pro audio FOSS community? 2.) Concerning our Jack vs. Jackdmp decision: http://jackaudio.org/ says, Jackdmp is going to be Jack 2.0. How likely and how soon do you think is this going to happen? 3.) I guess, there is a very minor bug in the lines 236, 237 of libjack/driver.c, svn revision 2734: The type castings should be switched. Thanks a lot in advance and please excuse my bad english :(. Regards, micu BTW: I love Jack and I love ardour --- and therefore I love you :). ========================================== [1]http://www.realtimelinuxfoundation.org/variants/variants.html#VARIANTS_DR… [2]http://www.osnews.com/story.php/15814/Introduction-to-TUD-OS/ [3]http://demo.tudos.org/dsweeper_tutorial.html [4]http://www.alsa-project.org/main/index.php/SALSA-Library [5]http://www1.inf.tu-dresden.de/~s3418892/task.txt [6]http://www1.inf.tu-dresden.de/~s3418892/Require.pdf [7]http://www1.inf.tu-dresden.de/~s3418892/AgttJSC.txt -- GnuPG: https://www1.inf.tu-dresden.de/~s3418892/micuintus.asc Fingerprint: 1A15 A480 1F8B 07F6 9D12 3426 CEFE 7455 E4CB 4E80

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Linux-audio-dev July 2008