Linux-audio-dev

linux-audio-dev@lists.linuxaudio.org

3 participants
7536 discussions

by Justin Smith

Is anyone out there using the ocaml bjack library? I am going to be working on a program that interprets an svg file as a synthesis graph, with just the basic puredata objects to start with. I will be using inkscape as the editor for the synthesis graph (polygons are processing units, diagram connectors are signal paths). It seems like, with the higher level processing I will be doing on the input .svg xml file, ocaml would be an interesting language to use for this. Has anyone out there used the bjack library for ocaml, and if so would you happen to have some example code I could look at, like maybe a program that just passes its input to its output? Google is not helping me much, mostly getting stuff related to the debian/ubuntu packages, and not the use of the library.

16 years, 7 months

Re: [LAD] USB2 audio?! (Re: Alesis AudioLink)

by Jonathan Woithe

Hi > On Wednesday 08 July 2009 17:43:47 Juhana Sadeharju wrote: > > Why Linux does not support USB2 audio devices? > > Where is the problem? (How can I help?) > > Repeating the archive: For a rather long time, there was no usb2 audio > standard. Each device had its own proprietary protocoll only the vendors know. > Hard to support in linux. Now there is a standard. But no device actually uses > it because they all already have their own protocols. So in the end nothing > has changed. > > And except from making the vendors publish their specs, there is nothing you > can do. This is of course very close to the problems we had with firewire devices: there were published standards but they weren't always used. The difference here was that some vendors *did* adopt the standard which made things a bit easier. Even so, most still utilised vendor-specific extensions (especially for device control). AFAIK FFADO got started through the cooperation of one or two vendors and as momentum has built additional vendors have come on board to a greater or lesser extent. I expect something similar will have to happen for professional USB2 audio devices to be generally supported under Linux. Of course the other way around the problem is to do protocol analysis, but this really is the "last resort". However, in many ways this is harder on USB because as I understand it you can't have two USB bus hosts (ie: two PCs) connected to the same bus. You can probably do it using virtualisation so long as the virtualiser supports USB passthrough. The kernel's usbmon facility may then give access to the traffic as it flows. For this to work you'll need a pretty fast PC since you'll be running audio applications under a virtualised environment - I'm not sure the required timing can be met even on today's fastest hardware. In any case, there will be a lot of work involved in getting a start on this if vendor documentation is not forthcoming. I should add that from my point of view, drivers written without vendor support are really to assist those moving to Linux from other platforms who already have considerable investment in interfaces which they cannot or will not replace just to switch platforms. If considering the purchase of an interface specifically for use under Linux I would encourage you to purchase from a vendor who actively supports Linux - thereby giving them a reason to keep doing so. Regards jonathan

16 years, 7 months

Re: [LAD] Linux-audio-dev Digest, Vol 29, Issue 7

by Jeff McClintock

Hi Chris, > > " 3.4 ?Install any non side-by-side shared files to the correct > locations > I've only just got around to reading this properly, but it seems to be > saying the opposite of what you said -- it seems to be saying that > components that are shared across multiple vendors (such as audio > plugins of this type, presumably) may indeed be placed in the system > directory. Am I reading it wrong? "to ensure backward compatibility" i.e. The old way was to write dlls to the system directory. This is the cause of 'dll hell' - updating one application breaks another. Windows now bends over backward to avoid this. The new way is 'side-by-side' system components where each version gets it's own directory. Virtualization ensures each application uses the version is was originally written with. Side-by-side doesn't apply to application plugins I think, more intended for operating system components. Shared plugins go in "../Program Files/Common Files/" Best Regards, Jeff

16 years, 7 months

[LAD] USB2 audio?! (Re: Alesis AudioLink)

by Juhana Sadeharju

Why Linux does not support USB2 audio devices? Where is the problem? (How can I help?) USB2 digital TV device seems to output 10 GB in one hour. That would match 28 channels of audio. Juhana

16 years, 7 months

[LAD] RFC: Default discovery paths for LADSPA, LRDF, LV2 and DSSI (and more?)

by Stefano D'Angelo

Hello LADSPA, LV2 and DSSI specifications do not reccomend default discovery paths where hosts may look for plugins, which IMO is bad for the end user because: * end users shouldn't be asked to know about path environment variables by reading documentation in header files or looking for it on the web; * when their environment path variables are not set, some hosts choose to scan some hard-coded directories, but this changes among hosts and gets a lot worse on non UNIX-like operating systems (read Windows) - for example some might look inside some subdirectory of the current user's home, others might only look in /usr/lib/<api>, etc. Hereby I propose some default paths which could be used, in the hope that API authors lurking around here might want to recommend them and host authors might want to use them: LADSPA Unix-like OSes with FHS/Unix-like filesystem layout: /usr/lib/ladspa, /usr/local/lib/ladspa, ~/.ladspa Windows: %PROGRAMFILES%\LADSPA, %APPDATA%\LADSPA Mac OS X: /Library/Audio/Plug-Ins/LADSPA, ~/Library/Audio/Plug-Ins/LADSPA DSSI Unix-like OSes with FHS/Unix-like filesystem layout: /usr/lib/dssi, /usr/local/lib/dssi, ~/.dssi Windows: %PROGRAMFILES%\DSSI, %APPDATA%\DSSI Mac OS X: /Library/Audio/Plug-Ins/DSSI, ~/Library/Audio/Plug-Ins/DSSI LV2 Unix-like OSes with FHS/Unix-like filesystem layout: /usr/lib/lv2, /usr/local/lib/lv2, ~/.lv2 Windows: %PROGRAMFILES%\LV2, %APPDATA%\LV2 Mac OS X: /Library/Audio/Plug-Ins/LV2, ~/Library/Audio/Plug-Ins/LV2 Plus, we could do the same for LRDF data: Unix-like OSes with FHS/Unix-like filesystem layout: /usr/share/ladspa/rdf, /usr/local/share/ladspa/rdf, ~/.ladspa/rdf Windows: %PROGRAMFILES%\LADSPA\rdf, %APPDATA%\LADSPA\rdf Mac OS X: /Library/Audio/Plug-Ins/LADSPA/rdf, ~/Library/Audio/Plug-Ins/LADSPA/rdf What do you think about it? Stefano

16 years, 7 months

Re: [LAD] RFC: Default discovery paths for LADSPA, LRDF, LV2 and DSSI (and more?)

by Jeff McClintock

> From: Chris Cannam > On Thu, Jun 25, 2009 at 9:13 PM, Jeff McClintock<jef(a)synthedit.com> > wrote: > > Windows has official rules for this. ?Users are no longer allowed to > add > > random files to an application's directory in "/Program > Files/Appname". > > Oh! This is news to me -- interesting news too, given that I > distribute Windows versions of SV without an installer and just expect > the user to copy it to %ProgramFiles% if they want it to go there, and > that it only looks in immediate subdirectories of %ProgramFiles% for > plugins of any sort. > > I don't recall anyone complaining to me that they couldn't install > plugins for it -- maybe this just means nobody is using it?! On Windows XP, many people run as administrator, so they won't notice anything. On Vista and Windows 7, they will get a 'UAC' Warning that they are doing something restricted. > Can you point to any documentation for this? I'd like to know what > other rules I might be falling afoul of. http://msdn.microsoft.com/en-us/library/ms995843.aspx (most of that is about system dlls and versioning). The relevant part for plugins is... " 3.4 Install any non side-by-side shared files to the correct locations The proper location for shared components depends on whether these components are shared across companies or by a single company. Shared components that are private to a single software vendor must be installed in one of two places. Do not store these files in the system directory common files directory\<company name> %ProgramFiles%\<company name>\Shared Files The common files directory can be accessed by passing CSIDL_PROGRAM_FILES_COMMON to the SHGetFolderPath API." > typically > > "C:\Program Files\Common Files\LADSPA Plugins..." > > I don't suppose you happen to know whether any Windows-based LADSPA > hosts are actually using this path? I don't know about LADSPA..but the latest Cubase uses "C:\Program Files\Common Files\Steinberg\VST2" for 3rd party plugins. Personally I think the company name could be omitted because many other individuals and companies need to put plugins in there too. Jeff M

16 years, 7 months

[LAD] implementing audio device driver on embedded platforms

by Jugalkishore Darak, Pankaj

Hello Developers, I am a newbie to the Linux development environment. We are porting Linux 2.6.25.4 to a platform which has ARM11 as its core processor. My job is to implement audio device driver. Most of the docs are meant for PC audio which has sound cards on PCI. And the source code resides in sound folder under the kernel root. Since mine is an embedded platform, where will my architecture specific code resides? Which all folders under sound folder will be used for embedded devices and which APIs to look into? Which APIs will be called for system sounds ? Can anybody share their experience in implementing audio device driver on embedded platforms? Thanks a lot in advance. Regards, Pankaj

16 years, 7 months

[LAD] [ANN] Invada Studio Plugins - version 1.1.0

by Fraser

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Everyone, I've released a new version of the Invada LV2 plugins. Major changes are: * Added new plugin: 'Delay - Munge'. A delay with non-linear response in the feedback loop. The 'munge' affect is more noticeable the higher the feedback. Also features a LFO and delay calculator. Screenshot: http://www.invadarecords.com/images/downloads/Screenshot-Invada_Delay_Munge… * Added new plugin: 'Test Tones' This was more for myself but others may appreciate this. Just a simple sine oscillator but via the custom GUI the frequency can be set to well known calibration and musical frequencies. Useful if you need to fault find, calibrate analogue equipment or if desperate to tune an instrument when you have no tuner handy. * Eliminated 'zipping' from changing controls. All plugins now handle parameter changes (across the entire range) without producing any audio artefacts ('zipping' noises). No issues with automation of controls. * Filters now adjustable from the display Adjust filters by dragging the response curve about one the display within the filter plugins. * Some RDF updates + ladspa URN as per http://lists.lv2plug.in/pipermail/devel-lv2plug.in/2009-June/000226.html + Added extended port properties to rdf (log) * Numerous tweaks/improvements. People using lv2rack version 4 should upgrade to version 5 before using this release as I've backed out a workaround from version 1.0.1 which was done just to support version 4 of lv2rack. Download is here: http://www.invadarecords.com/Downloads.php?ID=00000264 Ubuntu packages here: https://launchpad.net/~invada/+archive/ppa cheers, Fraser -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFKUJanNZroiEh4erwRAr6ZAJ9CDgBrY7Q4ENIH3ymrmma7YJym6QCfc08b 17B/ZGMUvHgedRZ6CnMHK1g= =JCt2 -----END PGP SIGNATURE-----

16 years, 7 months

[LAD] help on creating MIDI from linux input events

by Renato Budinich

Hello to all, I would like to write a program which does the following: detect the input events generated by a usb device which i own - the Rig Kontrol 2 from Native Instruments which is a pedal board intended for guitar use and which already has a linux driver - and trigger with those midi messages; i.e, pushing a button would create a midi note on/off, rolling the pedal a midi CC. As said, the pedal produces already linux input events so it would be a matter of creating a midi client (jack or alsa), grab these events and create midi from them. I would then use these midi messages to control Jack applications (mostly rakarrack) My C/programming knowledge is basic, so I ask your advice: 1) would it be easier to achieve this through jack or alsa? I'm confused here because jack applications i use - hydrogen for example - for what concerns midi, they all appear under the ALSA tab in qjackctl's Connection window. Are they really alsa midi clients being wrapped by jack? Is there a reason for writing alsa midi clients instead of native jack midi clients? So my problem is if i should learn the jack api or the alsa one. 2) Once I've decided on 1), which is the best place to document myself? I would prefer, if possible, to learn only what i need for this simple project - which for me btw is anything but simple. I mean not learning the whole jack or alsa api if i'm only going to use the basics. I really want to do this, but as you can see it's a difficult project for me. It would be wonderful if someone could give me kind of detailed advice on what "bricks" i'll need: relevant functions from the apis, general code structure and well, anything that will make me life easier :) thank you, Renato

16 years, 7 months

[LAD] Version 0.2 of uli-plugins

by Ulrich Lorenz Schlüter

Hi, I released version 0.2 of uli-plugins a series of LV2 plugins. I added some latches and flipflops. http://sourceforge.net/projects/uli-plugins/ Regards Uli

16 years, 7 months

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Linux-audio-dev