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does sndfile-convert apply dither when reducing wordlength?

by Jörn Nettingsmeier

if not, an option to do so would be cool. best, jörn

15 years, 2 months

malloc in fftw

by Maarten de Boer

Hi, I suppose that many of you are or might be using fftw for real-time audio processing, and I think the following information may be of your interest. I just came to realize that fftw_execute calls malloc. This happens even though you create a 'plan' where you pass fftw_malloc preallocated input and output buffers. It goes without saying that calling malloc is bad practice for audio callbacks, but as a reference I quote the jack_set_process_callback documentation: The code in the supplied function must be suitable for real-time execution. That means that it cannot call functions that might block for a long time. This includes malloc, free, printf, pthread_mutex_lock, sleep, wait, poll, select, pthread_join, pthread_cond_wait, etc, etc. I wrote the fftw developers and they confirmed the memory allocation takes place. They suggested the following: > Try planning with the undocumented flag FFTW_NO_BUFFERING, which will > prevent the use of malloc() in common cases. This is not > foolproof---some transforms are very hard to do without additional > buffers, but if all you are trying to do is vanilla out-of-place 1D > transforms without large prime factors it should work. Maarten

15 years, 2 months

MF-401 Auto De-tune

by Jens M Andreasen

The MF-401 can be used to treat your vocals to be off-key in a variety of ways. Presets include: •Drunk as a Sailor •Seattle sensitive alternative warble •Where did all the green room beer go? http://www.moogmusic.com/moogerfooger/?section=product&product_id=21374

15 years, 2 months

[OT] Handle/Mobile devices

by Marco Castorina

Dear all, I'm collaborating with a lecturer on creating tests to deliver to users for research purposes. His idea is to deliver them using mobile devices like the iPhone and I'd like to use one of the OS devices like the Neo FR, Pandora or even Indamixx. The problem is that, if it all goes well, we'd need a lots of them (50/100), so I'm looking for something cheaper at the moment. Do you have any idea/suggestions? Of course I prefer OS devices. Thanks all, as always! Marco Send instant messages to your online friends http://uk.messenger.yahoo.com

15 years, 2 months

jack-session finally merged.

by torbenh

hi... jacksession stuff is merged into jack1 svn. here is a rough explanation what needs to be done for apps to support it: http://trac.jackaudio.org/wiki/WalkThrough/Dev/JackSession please let me know what is unclear. -- torben Hohn

15 years, 2 months

Re: [LAD] [OT] Handle/Mobile devices

by Marco Castorina

> One part of my income I make as > a IPhone developer so let me tell you, deploying on IPhone/Ipod is pain. Its > very likely that your app is rejected by Apple because of the limited use so > you have to deploy on your own. With the developer account you can only > deploy on up to 99 devices and the app is time limited, cant be started > after some months. Without it (and a Mac) nothing. That's why I want to stay away from Apple, at least for the moment. > You already suggested game handhelds so possibly a Dingoo A320 would be > enough. Input is limited to joypad and some buttons but for a simple > multiple choice test its enough. Results could be stored on miniSD card. > The Dingoo costs around $60-$80. This is really interesting, looks like a small DS. > The next would be a GPH Wiz which offers pen input, its the successor of > GP2X, setting you back with $120-$140 And this one is even better. I like the idea of having stylus input. > Or get one of these for $99 with keyboard > http://www.engadget.com/2010/03/15/qi-hardwares-tiny-hackable-ben-nanonote-… You're the second one suggesting this one. It's not too far from Pandora, but it's cheaper and closer to a smartphone from a dimension point of view. Do you have experience developing for these? Is it difficult or it's like any other Linux based system? >Cheers, > Malte Thanks, Marco Send instant messages to your online friends http://uk.messenger.yahoo.com

15 years, 3 months

Re: [LAD] [Jack-Devel] Transport question

by Tim E. Real

On March 29, 2010 03:46:00 am Rui Nuno Capela wrote: > On Mon, 29 Mar 2010 02:42:12 +0200, salsaman(a)xs4all.nl wrote: > > On Sun, March 28, 2010 03:48, Tim E. Real wrote: > >> On March 27, 2010 07:54:21 pm Tim E. Real wrote: > >>> Hi list. Hi Salsaman. > >>> > >>> I built and installed Lives today. (Nice program!) > >>> > >>> I have now tested Lives, MusE, Rosegarden, and Ardour > >>> while running Jack-2. > >>> Each had blank default layouts, no tracks, except Lives > >>> which had one short video clip loaded. > >>> > >>> Guess what? They ALL stop unexpectedly at random times > >>> while rolling and hitting 'Rew' and 'FF' in QJackCtl. > >>> Even worse, they ALL fail to start sometimes when hitting 'Play' > >>> in QJackCtl, which is what Salsaman observed with Lives. > >>> > >>> However, I discovered that the problem depends on Jack > >>> buffer size (frames/period). > >>> With 1024 or 2048 for example, it happens very frequently. > >>> With 128, it happens very rarely. > >>> > >>> What's going on here? Clearly there's a problem. > >>> A setting? A bug? System issues? > >>> > >>> Thanks. Tim. > >> > >> Oh no! > >> I just tried some of the same tests *without* QJackctl > >> and the problem disappeared. > >> To see if the problem may just be more than one app running, > >> I tried with MusE and Rosegarden running. > >> Rock solid, no trouble so far. > >> Strange considering QJackCtl is 'lightweight' compared to the others. > >> > >> I was sure that I tried this before without QJackCtl and it happened. > >> > >> Looks like this topic should move back to LAD now. > >> Sorry for the noise. Will report back if anything changes, > >> with my luck, it just might. > >> > >> Rui and Salsaman what do you think about all of this? > >> > >> Thanks. Tim. > > > > As I reported, it was working fine for me using jack_transport, so I > > think > > > it is quite possible that something is going wrong in qjackctl. It would > > be interesting to trace the jack calls in qjacktl to confirm whether or > > not it is sending the transport stopped messages, and if so figure out > > what is causing it to do so. > > qjackctl issues jack_transport_stop() when you press its "pause" button. > similarly, jack_transport_start() when you press the "play" button. "rew" > and "ffwd" buttons just do de/incremental jack_transport_locate()'s -- this > has been like so and quite happily for way more than 5 years now :) > > it is funny that when you put lives in the picture and things behave > strangely you infer that the problem is something else. you already made > evidence that when *lives is not running* everything works as expected. > > imho, i'll reiterate that you should revise lives' jack_sync_callback, > probably it is misunderstanding the jack transport sync api protocol, > somehow. > > cheers Hi list, hi Salsaman, hi Rui. Disturbing result: I discovered that QJackCtl, running all by itself with no other apps running, exhibits the problem. Run QJackCtl. Set the Jack size to a relatively high value like 1024 or 2048. Now play the transport. In the majority of attempts it will not start - goes into stop immediately. If it does manage to start, try FF or REW. Again, in the majority of attempts it will stop. Rui can you please take a look and try that simple test to verify? I broke in with KDbg, and it is calling qjackctlMainForm::transportStop() Looking at the stack trace, as far as I can tell: It seems that in qjackctlMainForm::refreshStatus() in the line: bool bPlaying = (tstate == JackTransportRolling || tstate == JackTransportLooping); bPlaying is false because the tstate is either JackTransportStopped (in the case of hitting play), or JackTransportStarting (in the case of hitting FF or REW while playing). This eventually seems to cause the call to qjackctlMainForm::transportStop() via the line: m_ui.PlayToolButton->setChecked(bPlaying); But I'm not sure because the stack trace is a bit hard to follow. Maybe in the end it is a Jack or even a system problem, really I just want to solve this. It's driving me nuts for months now. So I need your help to identify where the problem lies. Is it Jack or what? Thank you for your consideration. Tim.

15 years, 3 months

Re: [LAD] [LAA] [ANN] guitarix-0.07.0 release 'reloaded'

by Andreas Degert

2010/3/29 torbenh <torbenh(a)gmx.de>: > On Sun, Mar 28, 2010 at 11:33:12PM +0200, Andreas Degert wrote: >> >> - --quit doesn't work (unknown dbus command) > > yes. its not implemented yet. > >> - --quitas saves but doesn't quit the application > > the patch doesnt obey quit. i mailed it a bit too fast. > sorry. > >> - --quitas and --saveas only seem to save when called the first time with >> a session name > > do you mean a specifying the same session name twice ? > the SM refuses to overwrite existing sessions. > it doesnt print the error code, i think. > > i really need to give pyjacksm some love. i was focussing on getting > a couple of apps patched, and mainly tested using > > jack_session_notify save /full/path/to/session_dir > > it should be working correctly in jack1 svn r3976 > > >> >> - --load gives an exception, but works after killing the daemon > > i will go over jacksm now. > in dbus mode there are some problems. > >> >> - the saved command line contains -f ${SESSION_DIR}guitarix.state, but >> SESSION_DIR doesn't end with a /. Is just the slash missing in the >> command line or is the value of SESSION_DIR wrong (for now i have >> added a "/") ? > > yes. the slash was missing from the replaced value. > fixed in jacksm git now. > > the separators are os dependent. and i wanted to leave them out of the > API as much as possible. The current git version of jacksm works now for me. Guitarix also seems to work fine in a session, but i'm puzzled about weak linking. The function address (of jack_set_session_callback) is null depending on if its in libjack.so or not when ld is run, but independent of the version of libjack.so.0 at runtime. It seems as if the address is always bound lazily at function call time, not when the function pointer is checked for 0 (means it crashes when session support is compiled in but the libjack used at runtime doesn't support it). ciao Andreas

15 years, 3 months

digiface vs. multiface vs. jack vs. other cards

by Fernando Lopez-Lezcano

At CCRMA we have several studios with linux computers in them (in addition to computers sprinkled throughout the building). Some of the studios have digiface interfaces, some multiface. All of them are connected to the sound system or mixer digitally through adat lightpipes. Workstations have Delta 66 or Gina3G soundcards. It would be nice for a user to be able to play, say, a stereo Ardour session in any of them without any changes to the session or routing. The digifaces send channels 1-24 out the adat ports. The multifaces on the other hand send 9-16 on the adat port. Deltas and Ginas send out stuff on channels 1-4 or 1-6. You can see the multiface interfaces are a problem. To get sound out of them you have to send on channels 9-16 which is different from _all_ others! I tried several workarounds without much success: a) fix this at the alsa level. Should be the way to go, right? Create an /etc/asound.conf that uses ttable to translate channels for the multifaces so that the digital out is actually sent through channels 1-8 (and create the same name plug interface in all other computers that does nothing so that the user can set that name as the default in qjackctl and will get the same behavior in all computers). Works, but not quite. When I try to use that "fake" plug interface with jack2 I get a warning that I'm using a plug interface (sort of fair) and jack only opens it with _2_ i/o channels (even though the ttable is 18 channels wide!). If I _force_ input and output channels in jack to 18 it does work fine. But now it will _not_ work on other computers that have less (or more) than 18 channels. Argh. b) fix it in hdspmixer. Well, it turns out that hdspmixer does not read the default matrix gains from a file so I can't really override the default. AFAICT the gains are calculated algorithmically in the code and there is no command line option to load presets from a file. Or I could write a small script that will set the right gains for 1-8 to go out through 9-16 but if a user starts hdspmixer that gets undone with no warning. And, of course: c) give up and connect an 8 channel analog snake to the analog outputs of the multifaces and do away with a digital connection to the mixer... Anyone has any other suggestions?? This should be easy to fix, right? :-) -- Fernando

15 years, 3 months

[OT] Turing machine

by fons＠kokkinizita.net

If you know Turing's 'Computable Numbers' you may enjoy this: <http://aturingmachine.com> Ciao, -- FA O tu, che porte, correndo si ? E guerra e morte !

15 years, 3 months

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Linux-audio-dev