Linux-audio-dev

linux-audio-dev@lists.linuxaudio.org

4 participants
7502 discussions

by ssm

Hi, I started working with Linux audio very recently. Primarily, I wanted to understand the Linux audio stack and audio processing flow. As a simple exercise, - I write a simple capture/playback application for PCM interface and store the captured audio data in a .wav or .raw file - The device parameters I played with are: hw:2,0/plughw:2,0 (for USB headset) , 1/2 channel, 44100 sample rate, SND_PCM_ACCESS_RW_INTERLEAVED mode, period size 32, S16_LE format. - Use Ubuntu, kernel 3.9.4 and Logitech USB headset for development/testing To understand the control flow, I inspected the ALSA driver source code and got an understanding of the flow in kernel space. However, I am kind of lost in the user-space ALSA library. - What happens after ALSA handovers the data i.e. the audio data from mic is copied from USB transfer buffer to userspace buffer? What are the data processing steps? - Where is Pulseaudio working here? - Is there any software mixing happening? - In the USB sound driver, I changed the data in urb->transferbuffer to a pattern like 'abcdefghijklmnop', but in the capture application when I store the audio data in a .raw file, I don't completely get the data back. If I set 1 channel in the hw params, I get almost 'abcdefghijklmnop' pattern but sometimes get 'abcdefghijklm' i.e. the pattern incomplete and another pattern starts over. For 2 channels, the data interleaves in a pattern like 'ababcdcd...' but there are also some incomplete patterns and also I see some unexpected characters. I know it's a long post, but even if you can help with a part of it, I'll be greatly benefited. Thanks! -- View this message in context: http://linux-audio.4202.n7.nabble.com/Linux-Audio-Architecture-tp85571.html Sent from the linux-audio-dev mailing list archive at Nabble.com.

12 years

fireflies

by Fons Adriaensen

Hello all, Returning home late, on the way from the car parking to my door I was greeted by a nebula of hundreds of fireflies doing their social thing. A lovely thing to see, but it also reminded me that I should really post the following: The last months I'm receiving lots of invitations to join Circles, Friends, Contacts etc. etc. on Google+, Facebook, LinkedIn etc. etc, many of which from members of this list. While I do appreciate the motivation behind such requests, I will never accept them, and from now on I will also stop responding to any such invitations. If you want to discuss anything (Linux) audio you're welcome to get in contact via private email or the LAU or LAD mailing lists. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow)

12 years

AVB on Linux coming to life

by Adrian Knoth

Hi! Just a very brief update for those who care about AVB on Linux: We've recently discussed the subject at LAC 2013 and agreed to use the open-avb-devel mailing list for "our" internal communication. Last Friday, we came closer to a working solution. I've already shared the status quo in a private e-mail with involved parties, one of them being Intel. Long story short: the follow-up to this e-mail will be crossposted to open-avb-devel, which means discussion is open to all. So if you care about AVB on Linux, you are more than welcome to subscribe to https://lists.sourceforge.net/lists/listinfo/open-avb-devel and share your views. Note that all this is very early development and highly technical, especially since there is no definite kernel<->userspace API, yet. Cheers

12 years

FLAC 1.3.0 released

by Erik de Castro Lopo

Dear Free Audio Tool Lovers, I am very pleased to announce the first official release of FLAC, the Free Lossless Audio Codec, in over 6 years. FLAC is not dead! It is however a mature software product that is now being maintained by a team working under the auscpices of the Xiph.Org Foundation. The executive summary of changes in this new version: * Nothing major. * Source tree is now hosted in Xiph.org git: git clone git://git.xiph.org/flac.git * Read and write appropriate channel masks for 6.1 and 7.1 surround input WAV files. * Added support for encoding from and decoding to the RF64 format. * Lots of build system fixes for your building enjoyment. The full changelog is here: https://www.xiph.org/flac/changelog.html Happy lossless encoding and decoding. Cheers, The FLAC project contribitors

12 years

14-bit CC / (N)RPN midi controllers question

by Tim E. Real

Lacking access to the full midi specs document, I don't know if this question is addressed. I've looked at manuals for products which support them and searched the web but I don't see a clear answer to my question: Is it safe to assume that a product or app which allows binding a *single* HW or GUI control to either 14-bit CC or 14-bit (N)RPN, would *always* send the value LSB, even if the LSB did not change but the MSB did, when the control moves? Do the midi specs address this? Or do you know of examples of such LSB optimizing-out? Thanks. Tim.

12 years

Laborejo Release version 0.8 (More of the same - Only better)

by Nils Gey

Laborejo 0.8 is released We are still in Beta. Streamlining, fixing and making things more robust is the main feature. However, there are a few new features: - Swing for Playback mode. In the Performance Signature. - More preview and export options, especially for Lilypond - Jack Transport start and stop sync. (Update calfbox as well!) - "Did you know" help screen and splash dialog (optional) There is a 0.85 release planned which will deal with making containers, selections and undo work together properly and implementing the last small features on my todo-list. After 0.85 the plan is to work on speeding up the performance and writing documentation and translations. And the usual bugfixes of course. This will transition smoothly into a stable 1.0 release Since Laborejo now becomes more useful and usable with each release it became fair to accept donations. There is now an extra donation page on the website. Please have a look. Your support would be much appreciated: http://laborejo.org/Donation Latest Screenshot: http://www.laborejo.org/latestscreenshot.png Download Page: http://laborejo.org/Download Greetings, Nils Gey Contact: http://laborejo.org/Support_and_Community

12 years

[ANN] Qtractor 0.5.9 - The Juliet Quebec release

by Rui Nuno Capela

As an anticipated summer delight... Qtractor 0.5.9 (juliet quebec) is now released! Release highlights: * NSM support (NEW) * Audio buses plugin state restoration (FIX) * MIDI channel file merge/export (FIX) * MIDI editor rescale mode (NEW) * German translation (NEW) Website: http://qtractor.sourceforge.net Project page: http://sourceforge.net/projects/qtractor Downloads: http://sourceforge.net/projects/qtractor/files - source tarball: http://downloads.sourceforge.net/qtractor/qtractor-0.5.9.tar.gz - source package (openSUSE 12.3): http://downloads.sourceforge.net/qtractor/qtractor-0.5.9-6.rncbc.suse123.sr… - binary packages (openSUSE 12.3): http://downloads.sourceforge.net/qtractor/qtractor-0.5.9-6.rncbc.suse123.i5… http://downloads.sourceforge.net/qtractor/qtractor-0.5.9-6.rncbc.suse123.x8… - quick start guide & user manual: http://downloads.sourceforge.net/qtractor/qtractor-0.5.x-user-manual.pdf Weblog (upstream support): http://www.rncbc.org License: Qtractor is free, open-source software, distributed under the terms of the GNU General Public License (GPL) version 2 or later. Change-log: - Auto-incremental version numbering of backup session files; brand new versioning mode option added. - Fixed one long as ever MIDI file export bug, which was about washing all self-induced MIDI bank-select (CC#0, CC#32) and program-change (PC#) events into MIDI channel 1, regardless of the source track/channel. - Fixed initial sample-rate settlement on plugin chains for all tracks and buses whenever a session file original sample-rate differs from the current audio device engine (ie. JACK). - New German (de) translation added (by Guido Scholz, thanks). - Now accepting JACK transport tempo and time-tignature changes while in slave transport mode. - Fix ref-count and auto-removal of created files that result from clip merge/export when session is closed but not saved. - MIDI track instrument bank/program selection, from plugin UIs that support it, is now effectively and complete. - Custom connections for dedicated audio outputs from all plugin chains in MIDI tracks or buses are back in business, hopefully restored gain on session load (ticket by yuba, thanks). - Track Properties dialog now dirty after any plugin related change (another head-up by yuba, thanks again). - Tempo Map/Markers dialog is not set initially dirty anymore. - Audio buses plugin state's persistence were found AWOL: while being properly saved as usual, were being restored to default on every session reload (as noticed by yuba, thanks). - NSM (Non Session Management) support is being introduced. - The MIDI clip editor (aka. piano-roll) gets a brand new rescale mode: ctrl+dragging the right edge of a note now rescales all times and duration of all the subsequent selected notes (after an interesting idea/ticket by Joel Leclerc, thanks). - The new MIDI clip editor rescale mode also applicable to event values (eg. note velocities, pitch-bend), while ctrl+dragging the edges of an event vertical bar. - VST plugin (GUI) idle timer makes a comeback. - Hard-wired LV2 UI selection order for plugins which supply more than one option (lv2_external_ui gets always honored first then, as provided via libsuil, X11, GTK and last but not least, Qt4). See also: http://www.rncbc.org/drupal/node/664 Have (lots of) fun. -- rncbc aka Rui Nuno Capela rncbc(a)rncbc.org

12 years

[ANN] Vee One Suite 0.3.3 - Late spring blossoming

by Rui Nuno Capela

hello june, a new batch of the so called Vee One Suite of old-school software instruments is out: synthv1 [1] polyphonic synthesizer, samplv1 [2] polyphonic sampler and drumkv1 [3] drum-kit sampler, are slowly maturing. as before delivered still in dual forms, each with their own amenities: - a pure stand-alone JACK client with JACK-session, NSM (Non session management) and both JACK MIDI and ALSA MIDI input support; - a LV2 instrument plugin. major release highlights: - LV2 External UI extension support; - NSM (Non session management) support. aha, and each one of the contraptions also got their own ordinary icon color personalities, whatever. I'm sure you'll notice. all free, open-source Linux Audio software, distributed under the terms of the GNU General Public License (GPL) version 2 or later. there they are: [1] synthv1 - an old-school polyphonic synthesizer synthv1 is an old-school all-digital 4-oscillator subtractive polyphonic synthesizer with stereo fx. LV2 URI: http://synthv1.sourceforge.net/lv2 website: http://synthv1.sourceforge.net downloads: http://sourceforge.net/projects/synthv1/files - source tarball: http://download.sourceforge.net/synthv1/synthv1-0.3.3.tar.gz - source package: http://download.sourceforge.net/synthv1/synthv1-0.3.3-10.rncbc.suse123.src.… - binary packages: http://download.sourceforge.net/synthv1/synthv1-0.3.3-10.rncbc.suse123.i586… http://download.sourceforge.net/synthv1/synthv1-0.3.3-10.rncbc.suse123.x86_… [2] samplv1 - an old-school polyphonic sampler samplv1 is an(other) old-school all-digital polyphonic sampler synthesizer with stereo fx. LV2 URI: http://samplv1.sourceforge.net/lv2 website: http://samplv1.sourceforge.net downloads: http://sourceforge.net/projects/samplv1/files - source tarball: http://download.sourceforge.net/samplv1/samplv1-0.3.3.tar.gz - source package: http://download.sourceforge.net/samplv1/samplv1-0.3.3-10.rncbc.suse123.src.… - binary packages: http://download.sourceforge.net/samplv1/samplv1-0.3.3-10.rncbc.suse123.i586… http://download.sourceforge.net/samplv1/samplv1-0.3.3-10.rncbc.suse123.x86_… [3] drumkv1 - an old-school drum-kit sampler drumkv1 is (yet) an(other) old-school all-digital drum-kit sampler synthesizer with stereo fx. LV2 URI: http://drumkv1.sourceforge.net/lv2 website: http://drumkv1.sourceforge.net downloads: http://sourceforge.net/projects/drumkv1/files - source tarball: http://download.sourceforge.net/drumkv1/drumkv1-0.3.3.tar.gz - source package: http://download.sourceforge.net/drumkv1/drumkv1-0.3.3-6.rncbc.suse123.src.r… - binary packages: http://download.sourceforge.net/drumkv1/drumkv1-0.3.3-6.rncbc.suse123.i586.… http://download.sourceforge.net/drumkv1/drumkv1-0.3.3-6.rncbc.suse123.x86_8… see also: http://www.rncbc.org/drupal/node/661 enjoy && rave on! -- rncbc aka Rui Nuno Capela rncbc(a)rncbc.org

12 years, 1 month

[ANN] New Jack / LV2 Host with socket support

by Ricardo Crudo

Hi LAD! We, from MOD <http://portalmod.com/en> team, released now a new Jack / LV2 Host in github: the mod-host. mod-host is a command line application like jalv, but that accept multiple instances and can be controlled via socket or shell. LV2 features currently supported: * lv2core * atom * event * buf-size * midi * options * uri-map * urid * worker More information can be found on README file. repo: https://github.com/portalmod/mod-host We hope that mod-host can be useful for others projects! Best Regards, Ricardo Crudo.

12 years, 1 month

Xiph.org - Video:Digital Show and Tell - No difference between analog and digitally processed sound.

by Barney Holmes

Thought the list would find this valuable. http://wiki.xiph.org/Videos/Digital_Show_and_Tell I was under the impression that there was some fundamental difference between the sound of analog and digital audio. But Monty Montgomery of Xiph.org completely annihilates this misconception with some clever use of analog sound reference equipment fed through a digital process and then out to an analog oscilloscope, vs. feeding direct from analog to the oscilloscope. The results are identical. I think Xiph have done the open source music community quite a service here because it completely trumps, in my opinion, the perception that electronic music put through a digital process is somehow "inferior" to analog music. ~~~ Home site - http://djbarney.org

12 years, 1 month

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Linux-audio-dev