Linux-audio-dev December 2005

linux-audio-dev@lists.linuxaudio.org

61 participants
53 discussions

[linux-audio-dev] [ANN] DRC: Digital Room Correction 2.6.2

by Denis Sbragion

Hello, DRC generates digital room correction FIR filters to be used within HiFi systems in conjunction with real time convolution engines like BruteFIR. Changes in version 2.6.2: A new command line parameters replacement functionality has been introduced. The dip and peak limiting procedures have been improved in order to avoid numerical instabilities. A new wavelet based analysis graph has been added to the sample results. Many performance improvements have been introduced. A new optional parameter used to define the base directory for all files has been added. Best of listening, -- Denis Sbragion InfoTecna Tel: +39 0362 805396, Fax: +39 0362 805404 URL: http://www.infotecna.it

18 years, 8 months

[linux-audio-dev] Re: "declicking" algorithm?

by Kjetil S. Matheussen

Paul Coccoli: > > On a semi-related note, can someone recommend any Free libraries in C > or C++ that implement things like oscillators, filters, etc.? > http://www.iua.upf.es/mtg/clam/ http://ccrma.stanford.edu/software/stk/ --

18 years, 8 months

[linux-audio-dev] "declicking" algorithm?

by Paul Coccoli

Here's a poorly written description of my problem (the code in question is written from scratch in C++, BTW): I have a simple gain function that takes a number between 0 and 1 and multiplies each input sample by that number. If I use the output of an LFO to get that gain number, I gets clicks in my output (presumably on when the LFO output changes by and number close to 1, as it would with a pulse/square wave). How can I get rid of these clicks? Do I need to "smooth" the output of the LFO, or my processed output? If so, what is a good way to do that? On a semi-related note, can someone recommend any Free libraries in C or C++ that implement things like oscillators, filters, etc.?

18 years, 8 months

[linux-audio-dev] Wine asking for feedback on Audio needs [redirected from LAU]

by Dave Phillips

This message appeared recently on the LAU list. On the chance that there may be developers here who have an interest : guy wrote: > According to wine weekly news (lhttp://www.winehq.com/?issue=301) the > wine project is asking for feedback on its handling of audio. If I > can quote: > > /Alexandre mentioned there were some new changes for better audio > driver management in winecfg. That work has been done by Robert Reif > and this week he asked if anyone could give him some feedback > regarding the lesser used (and more broken) audio drivers:/ > > /Is anyone using the arts, esound or jack sound drivers for non > trivial use? By non trivial, I mean more than one application or more > than a single device. If so, I am interested in getting information on > the software you are using and how it is using the drivers. / > > /Would redesigning these drivers to show up as a single device per > physical device which allowed being opened more than once be a problem?/ > > I am sure there are people on this list who know what they are > talking about ( & I exclude myself from that!) who could really speak > up for the requirements for serious audio work & wine. > > cheers > > Guy > >

18 years, 8 months

[linux-audio-dev] Jackd and cards with multiple PCM interfaces

by Jonathan Woithe

Hi all I am currently working on an ALSA driver enhancement for a card which actually contains two seemingly sample-locked ADCs. I'm making the second ADC accessable via a second PCM interface attached to the card. In general things work fine - under OSS emulaion I can open both (one as /dev/dsp, the other as /dev/adsp). However, jackd doesn't seem to know or care about the second pcm interface on the card and I can't find any obvious way to tell jack about it. It seems suitable entries in .asoundrc might help but it's not clear to me that this will work without xruns (see http://www.alsa-project.org/alsa-doc/doc-php/asoundrc.php). Can jackd work with multiple PCMs from the same card, and if so, what's the best way? Regards jonathan

18 years, 8 months

[linux-audio-dev] playing ascii?

by Aaron

Hi I need help with a conceptual and practical problem. How do you get sync between- audio/midi and ascii text plus notation displayed in a graphical program written in gtk+2? Here is the problem: I have notation is lilypond (www.lilypond.org) in a text editor, either vim emacs jedit or a custom text editor if need be. the audio of that text as midi or wav lets say the same notation displayed Graphically in Denemo (www.denemo.sourceforge.net) The result needed is: 1. to add text in the editor and have them show up graphically, and to add notes graphically and have them show up as text. Also the cursors in the applications should stay in sync. 2. Playback: To have audio playback of the sound either in midi or wav where the cursor in Denemo and the text editor stay in synce, and scroll karoke style. 2a. Have a scrub feature where a specific measure or set of notes can be played either from the ascii text or the graphic notation in Denemo. ------------------------------------------- So first conceptually how can this be acheived? Can I use a preexisting text editor such as VIM, Emacs or Jedit or must I create my own to acheive this? What libs scripts apps would help ease the implementation of the above. Is this a reasonable feature to hope to implement? And if it isn't, how could it be done anyways. thanks Aaron

18 years, 8 months

[linux-audio-dev] ALSA MIDI Sync

by Peter Brinkmann

Hi, I'm trying to figure out how to build an ALSA MIDI sequencer that'll sync with other sequencers. I've looked around but didn't see any recent information. (The closest hits were a five-year-old page of Takashi Iwai's, a three-year-old LAD thread with the subject line "MIDI sync and ALSA sequencer", and a LAU thread from last year, none of which sounded entirely encouraging.) So, my question is, what's the recommended way of synchronizing two MIDI sequencers these days, using ALSA? Is there any protocol (MTC, MMC...) that you would recommend so as to be compatible with a large number of other software packages? Any hints would be appreciated. Pointers to sample implementations of MIDI sync with ALSA would be great. Best, Peter

18 years, 8 months

[linux-audio-dev] Merging digital sampling sessions

by David Kastrup

Hi, I have a minidisc player with S/PDIF output and an ALSA supported soundcard (details if the card are not really important for the problem at hand). I sample recordings via arecord -D spdif -f cd Ok, and here is the rub: playback is not perfect, and neither seems to be the sampling. Probably at times error interpolation sets in, probably at times samples get lost or replicated. Not much, perhaps once per minute or so. This leads to audible clicks, of course. Then there are leading and trailing zeros. Now what I want to do is just sample the stuff three times and do a three-way merge. Never mind clever click detecting and interpolation schemes: just use redundancy. I have not found a tool for that. Anybody have a clue how to go about that? If things come to worst, I'll have to write a merging tool. Bonus points would be if the thing worked on-line, taking one recording, sampling new samples and just writing the diff out. Run this three times, then run a merge program on the first complete sampling as well as all diffs. That would save quite a bit of disk space. However, it is not really mandatory: just merging three full size files would be fine. Anybody have an idea whether there is some suitable starting point or utility for this kind of thing? -- David Kastrup, Kriemhildstr. 15, 44793 Bochum

18 years, 8 months

Re: [linux-audio-dev] dealing with complex numbers

by Taybin Rutkin

ISO C99 supports complex as a variable type and the GNU compiler supports that. Taybin -----Original Message----- From: Erik de Castro Lopo <mle+la(a)mega-nerd.com> Sent: Dec 13, 2005 4:05 PM To: The Linux Audio Developers' Mailing List <linux-audio-dev(a)music.columbia.edu> Subject: Re: [linux-audio-dev] dealing with complex numbers Artemiy Pavlov wrote: > Hey everybody! > > This may be a little bit off-topic, but can anyone suggest me any reading on > how to use complex numbers in C or C++? Is there any library or ++ classes > for such computations? In C++: #include <complex> which is a template clase. You can then do: typedef std::complex<double> dcomplex ; Erik -- +-----------------------------------------------------------+ Erik de Castro Lopo +-----------------------------------------------------------+ Open Source and Free Software means that you never sacrifice quality of the code for meeting deadlines set up by people not participating directly in the software development process.

18 years, 8 months

Re: [linux-audio-dev] dealing with complex numbers

by Taybin Rutkin

And by 'nando, I meant Eric. :/ Taybin -----Original Message----- From: Taybin Rutkin <taybin(a)earthlink.net> Sent: Dec 13, 2005 4:30 PM To: The Linux Audio Developers' Mailing List <linux-audio-dev(a)music.columbia.edu>, The Linux Audio Developers' Mailing List <linux-audio-dev(a)music.columbia.edu> Subject: Re: [linux-audio-dev] dealing with complex numbers Sorry, meant to include this link: http://developer.apple.com/documentation/DeveloperTools/gcc-4.0.1/gcc/Compl… http://www.gnu.org/software/libc/manual/html_node/Complex-Numbers.html 'nando's C++ usage looked a bit cleaner to me, IMHO. Taybin -----Original Message----- From: Artemiy Pavlov <artemio(a)kdemail.net> Sent: Dec 13, 2005 3:22 PM To: The Linux Audio Developers' Mailing List <linux-audio-dev(a)music.columbia.edu> Subject: [linux-audio-dev] dealing with complex numbers Hey everybody! This may be a little bit off-topic, but can anyone suggest me any reading on how to use complex numbers in C or C++? Is there any library or ++ classes for such computations? I'd appreciate any help. Thanks! With respect, Artemiy.

18 years, 8 months

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Linux-audio-dev December 2005