Linux-audio-dev January 2012

linux-audio-dev@lists.linuxaudio.org

57 participants
47 discussions

LAC Deadline Extension - now January 22, 2012

by Bruno Ruviaro

Dear All, The Linux Audio Conference submissions deadline has been extended! It is now January 22nd, 2012. So, if you were considering submitting a paper but couldn't make up your mind yet, here is your chance to become active! Never forget that this conference lives through the people participating in it. January 22nd is the new deadline for all submission types: papers, music, installations, workshop proposals. Notifications of acceptance will still be sent out on February 6th, 2012. Check out the link below more info: http://lac.linuxaudio.org/2012/participation Please spread this information to anyone who might be interested. Questions? Drop us a line at lac(a)linuxaudio.org We are looking forward to seeing you at Stanford in April! Thanks, The LAC 2012 organization team

12 years, 3 months

Automation with Ardour and DDX3216

by Frank Smith

HI Guys happy new year. Has anyone got the autofaders to work with Ardour and a DDX? I believe this is possible but can find no info as yet. Thanks for your time Cheers Bob

12 years, 3 months

Re: [LAD] send midi message

by Pedro Lopez-Cabanillas

On Thursday 05 January 2012, Dave Stikkolorum wrote: > On 05-01-12 15:31, Pedro Lopez-Cabanillas wrote: > > The problem in loop.c is that you are using the function snd_seq_ev_set_note() > > that includes a duration as the 5th parameter. This function will create two > > MIDI events in a queue, the first one will be the noteon event, and the second > > one will be a noteoff event, scheduled adding the specified duration to the > > start time of the former noteon event. That requires a queue for event > > scheduling. > So in fact with a message that contains a duration for a note is always > a queue involved? Yes, but this macro snd_seq_ev_set_note() is the only one that includes a duration parameter. It is not really a MIDI message, but the sequencer event is converted into two MIDI messages (noteOn + noteOff). There aren't MIDI messages containing durations. OTOH any event using the macros snd_seq_ev_schedule_real() or snd_seq_ev_schedule_tick() requires a queue as well, because the message delivering time will be scheduled in the future. Events using the macros snd_seq_ev_set_queue_control(), snd_seq_ev_set_queue_start(), snd_seq_ev_set_queue_stop(), snd_seq_ev_set_queue_continue() or snd_seq_ev_set_queue_tempo() also require a queue, because all these macros have a queue parameter. Regards, Pedro

12 years, 3 months

send midi message

by Dave Stikkolorum

Hi all, I try to write a c program that sends midi notes to the Hydrogen drum sequencer. I use the alsa library to create a client with an output port. I attached two files. loopqueue.c works but loop.c doesn't. A base drum (note:28) is being send. I am not succeeding to use direct delivery, but it only works with the queue. Any ideas why? Regards, Dave

12 years, 3 months

LMMS Trippleoscillator, LV2/linuxVST-version possitiblity?

by Aurélien Leblond

> My question is, quite simply, since LMMS is FLOSS, would making > Trippleoscilator + perhaps other instruments in LMMS into plugins > (lv2/linuxVST) be a realistic possibility? Bear with me, I'm no developer > but merely a musician, so I really don't know what I'm asking/talking > about. But I have a firm belief that a plugin-version of these instruments, > usable in for example Ardour3 when that arrives, would make a great > addition to the Linux-musician community. Technically it should be doable, but one would need to go in the code of LMMS to check it out. Sometime the code is almost usable directly in plugins. I'm working on porting the internal modules from AlsaModularSynth into LV2 plugins at the moment. Once I'm finished with that, I could take a look into it. (http://sourceforge.net/projects/avwlv2/) > (ps. Is there anything similar already existing perhaps? ds.) You should check AlsaModularSynth, coupled with Seq24... The instrument you described look like a synth with 3 oscillators (duuuuh, that would explain the name!). AMS comes with great examples, and building a Synth with 3 VCO (Oscillators) should be "pretty" easy. Yoshimi comes to mind as well (although it is way more complicated). Oh, and if you have some courage, feel free to try my plugins with Ingen :D P.S: I forwarded your mail to the LAU list. Some users there might have other ideas for similar synths. Hope that helps, Aurélien

12 years, 3 months

Denormals / subnormals (again)

by Carl Hetherington

Hi all, I have been looking into ye olde denormal problem a little, lately. Particularly with respect to Ardour and plugins. I've assembled what I believe to be a coherent statement of what is going on, but I'd very much appreciate any corrections and clarifications that anyone can offer. Here's how it seems to me: If you compile your code (e.g. a plugin) without -msse and -mfpmath=sse on the GCC command line you get *no* protection from denormals from the CPU. If they occur in your code, they will be very much slower than normal floating point numbers (~49 times slower on my Core 2 Duo, ~7 times slower on a Core i3). As far as I can see, it does not matter that Ardour has been built with those flags: if a plugin has not, you have no protection. If you compile your code with -msse and -mfpmath=sse, you have Ardour's protection from denormals. If the user's CPU supports it, you get there is no significant slowdown with denormals using this mode. However CPU support is "some later processors with SSE2", according to Intel. The problem, I guess, is that we cannot really distribute plugins with SSE instructions, otherwise we do not support people with older CPUs. In this case, I think the plugin code must avoid denormals, otherwise there will be a significant performance hit if they arise. I've been testing behaviour using a very dumb program which you can get from http://carlh.net/software/denormals.tar.gz I've also been testing plugins using a primitive torture tester that you can get from http://carlh.net/software/ or on github via git@github.com:cth103/plugin-torture.git Any comments? Best Carl

12 years, 3 months

USB-Audio and XHCI (USB 3)

by Aurélien Leblond

Hi everyone, I was wondering if anyone managed to run a USB 2 soundcard on a USB3 (XHCI) port? I'm running the kernel 3.2 rc7. With the M-Audio Fast Track Ultra (USB 2): The output of dmesg is this: [ 475.094595] usb 3-1: new high-speed USB device number 2 using xhci_hcd [ 475.108605] usb 3-1: config 1 interface 3 altsetting 0 bulk endpoint 0x7 has invalid maxpacket 8 [ 475.108615] usb 3-1: config 1 interface 3 altsetting 0 bulk endpoint 0x87 has invalid maxpacket 8 [ 475.108958] xhci_hcd 0000:04:00.0: WARN: short transfer on control ep [ 475.109328] xhci_hcd 0000:04:00.0: WARN: short transfer on control ep [ 475.109879] xhci_hcd 0000:04:00.0: WARN: short transfer on control ep [ 475.110564] xhci_hcd 0000:04:00.0: ERROR: unexpected command completion code 0x11. [ 475.110585] usb 3-1: can't set config #1, error -22 The snd-usb-audio module is not probed automatically, and if I modprobe it manually, no sound card is detected. The error message is described in this bug: https://bugzilla.novell.com/show_bug.cgi?id=679944 but if I understand well, kernel wise, everything is "ok" and the issue lies in Alsa The output of lsusb is: Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 003: ID 050d:0307 Belkin Components Bus 002 Device 003: ID 0408:1af1 Quanta Computer, Inc. Bus 001 Device 004: ID 046d:c51b Logitech, Inc. V220 Cordless Optical Mouse for Notebooks Bus 003 Device 002: ID 0763:2080 Midiman M-Audio RunTime DFU The Edirol UA-25Ex (USB 1) works fine, I get a few warnings in dmesg but the sound card is detected and functional... Let me know if I should provide any more info, or outputs, anything that can help. Kind Regards, Aurélien

12 years, 3 months

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

Linux-audio-dev January 2012