Linux-audio-user December 2008

linux-audio-user@lists.linuxaudio.org

144 participants
133 discussions

by confrey

Hi to everybody, I'm a new user of this mailing list; I use debian lenny and slackware on my notebook; I'm a musician, but only since a few time I'm trying ti use audio and musical software. I'd like - but I don't know if it's possible - to change 'volume' of a long note while a long note is playing, as I can do it manually changing a slider's position. I don't know how to do it, and which software I can use. I had a look to Rosegarden, QTractor and Muse, but I found never about. I'm a piano teacher, hi everybody confrey

15 years, 5 months

Play with latencies

by Jostein Chr. Andersen

Hi, I have played a little bit with the connections of latencies, distances and notes, just to get things in perspectives. We always try to keep the latencies as low as possible and I'm no exception: my every day standard is 2.9 ms, but decreases down to 0.72 in recording situations and maybe up to 20-50 ms when mixing (working in Ardour). So how long time (latency) does it tak from when you tap rhythm with the foot to you or other can hear it, and how is it between the members of a big orchestra? Big latencies are apparently very common in real life situations and it's fun to know about it. So here is the result of a wasted hour (hope every number is right), enjoy. Time in Length Note, ms in m 120 bpm Comments ======== ======= ======= =========================================== 1000.00 343.00 1/1 en.wikipedia.org/wiki/Speed_of_sound 500.00 171.50 1/2 Common delay speed (echo) 250.00 85.75 1/4 " 125.00 42.88 1/8 " 100.00 34.30 62.50 21.44 1/16 Distance between people in a big orch. * 46.40 15.92 Latency value 31.25 10.72 1/32 Wow, playing fast! * 23.20 7.96 Latency value 15.63 5.36 1/64 Playing real music that fast? Get a life! * 11.60 3.98 Latency value 10.00 3.43 7.81 2.68 1/128 Academic interest (musically) * 5.80 1.99 Latency value 5.00 1.72 Dist. from ear to foot 3.91 1.34 1/256 * 2.90 0.99 Latency value (64 f/p, 44100, 2 p/b) 1.96 0.67 1/512 * 1.45 0.50 Latency, common dist. to monitor 1.00 0.34 Not an uncommon distance to mic or wife 0.98 0.33 1/1024 * 0.73 0.25 Latency value 0.49 0.17 1/2048 Still of academic interest (musically) * The latency numbers is taken from qjackctl's setup dialog box when frames/period are from 16 to 1024 on a 44100 sample rate system with 2 periods/buffer. This shows that the quite common rule of keeping everything under approx 10 ms make sense, right? :-) Jostein

15 years, 5 months

MIDI NOTE ON/OFF Messages - reducing data

by Crypto

Hi LAU group, just a bit of brainstorming here. Defined in the MIDI specification is that for each NOTE ON message there has to be a NOTE OFF message (or a NOTE ON message with vol.=0). BUT: There are many instruments that in real life never need a manual action to stop their sound, for example most if not all percussion instruments and drums. For these, sound can "only" be triggered and then just plays, there is no way to stop it, apart maybe from rigorously damping it. It means: when playing vibes for example, the player hits the instrument once and then the sound just fades away. No action necessary to manally stop the sound. So: why do we have to send NOTE OFF messages for these kind of instruments? Wouldn't it be sufficient to simply sent the NOTE ON message for that sound and omit the NOTE OFF message? This would save us up to three bytes which can make a difference in delay. I'm not sure if this is true for drumkit sounds as one already has to define sound collections in a SF2 file either as instrument presets or drumkits. I'm not sure either how to introduce such a feature in the MIDI world, however, I can see that it might be rather difficult. Both sender (MIDI keyboard) and receiver (synth, expander, some software) need to agree that a particular sound does not need NOTE OFF messages and therefore the devices neither need to transmit nor wait to receive it. Maybe it could be done by introducing a new controller that disables NOTE OFF messages for a particular channel, so that all instruments that play on that channel would never need any NOTE OFF messages. Any comments/ ideas here? Crypto.

15 years, 5 months

: Netjack : like a charm :)

by Mysth-R

Hi, I just want to report my experience. Since several weeks now, I and a friend of mine were searching for a software, or an utility on Linux, capable of synchronizing our two computers. We could synchronize the transport, but there were always some things missing for the tempo... So yesterday, we decided to try netjack. Here our config : Two laptops connected via a router/switch with ethernet. One laptop with a sound card the other, just nothing. the laptop with a sound card was acting as the Master the other was acting as the Slave. On the Slave, you open a terminal and just run jackd with the net backend : $ jackd -R -d net So on the master you run jackd with qjackctl like you do normally. Then you open a terminal and run : $ jack_netsource -h 192.168.12.13 (the ip of the slave machine) That's all !! I couldn't imagine that it was so easy to use. And we played severals hour without any deconnection. Now I just have to sell my sound card :) ! By the way I would like to point up some things : * I would like to test the --celt option. But I can't understand what the "N bytes per period" option are. * It seems that xruns on the master computer made some desynchronizations. * On seq24, on the slave computer, I had to configure the option with "Jack Transport" AND "Master JACK" ... a bit disapointing... We lost so much time finding this very logical configuration. * So the problem was seq24 on the slave machine was running at this own tempo. If the master use 120BPM and the Slave 110, they are not synchronized. But if you put 120 on both, it seems to be synchronized... Well I think there is a bug in seq24 or something. I didn't try with other softwares. But I have some doubt about the real tempo synchronization. Thank you very much for this great apps that change our lives :) Cheers, Mysth-R -- * *************************************************************************************** * {^_^} Mysth-R {^_^} * <= Aide Auditive => * * http://myspace.com/mysthr * http://myspace.com/aideauditive * http://mysthr.free.fr/Joomla => Site dédié à l'audio sous Fedora/PlanetCCRMA. * ***************************************************************************************

15 years, 5 months

Asus EEE 1000 as new softsynth?

by Ken Restivo

I've purchased a new Asus EEE 1000 PC, and I love this thing. First off, almost everything on it just works with Linux, out of the box! I've never had a laptop on which everything actually worked properly. Audio, wireless, suspend-to-disk, even the webcam works with Debian EEE distro, out of the box! I was stunned. I've never experienced anything like this with linux. It's tiny, weighs almost nothing, has a usable keyboard, no moving parts (except the fan), runs a full linux distro, and sips battery power. I can stuff it into my backpack and I am in portable computing heaven. Because this thing is so many kinds of awesome, of course I want to run JACK on it and use it as my new softsynth for live performance purposes. I'm running Debian, using the 2.6.26 kernel (Lenny). I'm told that this kernel is completely unsuitable for Linux Audio work. However, I can't backtrack to older kernels because this one has all the hardware support I need. What kernel would you recommend for patching with Ingo goodness? This thing is a dual 686 Intel Atom at 1.2Ghz; with my good USB soundcard I'd expect to at least get a couple fluidsynth instances and LADSPA plugins going without incident. -ken

15 years, 5 months

Re: [LAU] Asus EEE 1000 as new softsynth?

by Johannes Mario Ringheim

Jay Vaughan skreiv: > On Fri, 2008-12-12 at 08:57 +0100, Johannes Mario Ringheim wrote: >> That sounds very nasty. Please allow me to ask a stupid question: Will >> this apply to external soundcards aswell? >> > > Nope. Use a USB Audio interface and you can minimize the damage. Hmmm... Fact is, I've tried, and cannot get anything but abysmal performance from jack. This is with ubuntu-eee 8.04, and a Behringer UCA202 USB interface. Which kind of distro, and/or configuration do you use..? Things I've tried: - linux-rt kernel - edit limits.conf (of course) - disabling systemlog, bluetooth and wireless - disabling pulseaudio - disabling compiz - all kinds of settings with jack Thanks for any input. -- Ringheims Auto - Fri musikk for bilstereo! http://ringheimsauto.org

15 years, 5 months

[ANN] QjackCtl 0.3.4 is out!

by Rui Nuno Capela

hi, A semester has gone by, since last release, with no big news on this front. Alas, on the verge of the coming one-dot-oh release of the mighty JACK Audio Connection Kit, here goes one fine update of its old and aged Qt GUI front-end: QjackCtl 0.3.4 is out! Nothing much new to see but you might welcome the patchbay snapshot revamp, which might finally do the right thing, and the rand new translations that are getting in place: German (de), Spanish(es), French (fr) and Russian (ru). Many thanks to all involved. With no further ado, the good stuff is ready from the usual places. Website: http://qjackctl.sourceforge.net Project page: http://sourceforge.net/projects/qjackctl Download: http://downloads.sourceforge.net/qjackctl/qjackctl-0.3.4.tar.gz Weblog: http://www.rncbc.org License: QjackCtl is free, open-source software, distributed under the terms of the GNU General Public License (GPL) version 2 or later. Change-log: 0.3.4 2008-12-05 Patchbay snapshot revamp. - Introducing the very first and complete translations in-package: German (de), Spanish (es), French (fr) and Russian (ru); credits in TRANSLATORS. - At last, after years of retarded procrastination, the old infamous patchbay snapshot feature has been the subject of a almost complete rewrite and it does try to give a way better mapping of all actual and current running client/port connections, both JACK (audio, MIDI) and ALSA MIDI, of course ;) - On Setup/Settings/Parameters dialog, all device selection options are now reset to default when disabled interactively. - Grayed/disabled palette color group fix for dark color themes. - Qt Software logo update. - Fait-divers: desktop menu file touched to openSUSE conventions. - ALSA PCM devices now only listed/enumerated iif strictly compliant with the audio mode criteria (Duplex, Capture-only or Playback-only) as kindly suggested by Nedko Ardaunov. - JACK client/port aliases may now be displayed as a global user option (see Setup/Display/Connections/JACK client/port aliases). - Lighten up the connections line and highlight colors, as seen to fit best on some darker background themes. - Patchbay snapshot fixed to differentiate socket clients according to its type (Audio, MIDI or ALSA-Seq), avoiding the mess and gross mistake of hanging disparate type ports under the same client item. - JACK_DEFAULT_SERVER environment variable is now appended to the X11 unique application identifier, allowing for having multiple instances each controlling its own JACK server, besides the default one. - Due to some trouble with newer Qt >= 4.4 applications regarding font size configuration, a new global user option is now available to the rescue: Setup/Misc/Defaults/Base font size (default is no-op). Cheers && Enjoy. -- rncbc aka Rui Nuno Capela rncbc at rncbc dot org

15 years, 5 months

Re: [LAU] Pre-configured Linux Audio laptop for US$499 gets some ink - Video Demos

by Ronald Stewart

Indamixx Atom Based Laptop/Netbook - Technical Video Multiple synth and drum tracks using energy XT2 default demo. http://www.youtube.com/watch?v=JOr2Q364kUQ Indamixx Laptop/Netbook Technical Video Setup - Live Scratching with Vinyl Control featuring Mixxx 1.6.1. http://www.youtube.com/watch?v=MYg3Fx9YDDo

15 years, 5 months

Feature trackers for Aeolus and AMS?

by rob

I have a few enhancement requests for Aeolus and AMS, but found none for Aeolus, and an apparently dead tracker for AMS. Does anyone know the right place for such requests? Cheers R

15 years, 5 months

Synchronizing 2 computer with MIDI

by Mysth-R

Hi, Yesterday I tried with a friend of mine to synchronize our computers with a simple midi cable. We just want to make music together, and synchronize, the transport AND the tempo with a Master and a Slave. After hours and hours of tests, we just made the transport sync works. But we couldn't sync the tempo. Someone told me on the #LAD IRC, about netjack, but it seems to be to "loud" for what we want to do. In fact, most of the softs can sync themself each other with JACK transport, but can't send Midi Time Code to the midi out. And when we even they can send Midi Time Code, it can't be sync with jack transport on the other computer. The top would be to find a soft which can act as a bridge between Midi Time Code and Jack Transport. like for exemple : First Computer : Seq24 -> Midi Time Code send to Midi out of the Sound card. Second computer : -> Midi Time Code received in the Midi In -> bridge on JackTransport -> and then each softs could be sync. The other solution : First Computer : Seq24 -> JACK Transport -> BRIDGEto Midi Time Code send to Midi out of the Sound card. Second computer : -> Midi Time Code received in the Midi In -> BRIDGE to JACKTransport -> and then each softs could be sync. Is someone knows a simple solution ? I am a bit disapointed Thank you for your help Cheers, Mysth-R -- * *************************************************************************************** * {^_^} Mysth-R {^_^} * <= Aide Auditive => * * http://myspace.com/mysthr * http://myspace.com/aideauditive * http://mysthr.free.fr/Joomla => Site dédié à l'audio sous Fedora/PlanetCCRMA. * ***************************************************************************************

15 years, 5 months

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Linux-audio-user December 2008