User: Password:
Subscribe / Log in / New account


The LV2 Audio Plugin Standard

By Forrest Cook
January 22, 2008

LADSPA, Richard Furse's Linux Audio Developer's Simple Plugin API, provides a plug-in framework for software audio effects. LADSPA applications are divided into two categories, host applications and plugins. From the LADSPA site:

LADSPA is a standard that allows software audio processors and effects to be plugged into a wide range of audio synthesis and recording packages. For instance, it allows a developer to write a reverb program and bundle it into a LADSPA "plugin library." Ordinary users can then use this reverb within any LADSPA-friendly audio application. Most major audio applications on Linux support LADSPA.

Recently, the LV2 Audio Plugin Standard was announced by Dave Robillard, the aim of LV2 is to replace LADSPA:

LV2 is a standard for plugins and matching host applications, mainly targeted at audio processing and generation. LV2 is a simple but extensible successor of LADSPA. intended to address the limitations of LADSPA which many applications have outgrown. While LADSPA has been quite successful with many plugins and hosts, it is quite limited and can't be extended without breaking existing implementations. LV2 in contrast is designed with extensibility in mind right from start.

One of the LADSPA limitations comes from the use of fixed data fields in the plugin binaries. LV2 defines its plugin data by using the Resource Description Framework (RDF) standard. This allows for a much wider variety of plugin data definitions. The RDF files also allow for the inclusion of multiple string definitions, which allows for plugin internationalization. The core LV2 code is intentionally designed to be small and generic, while allowing for support of independently designed extensions.

Plugin identification has been changed from an ID number to a URI, this allows for extended capabilities such as the reference or fetching of plugins across the network. While LADSPA only used floating point numbers for port connections, LV2 supports port type extensions. This can be used to handle MIDI, OSC (OpenSound Control), frequency domain and other types of data. LV2 bundles of all of the data for each plugin into a single directory for easy access. As with ALSA, the actual lv2 core specification is relatively simple, the lv2core-1.tar.gz source file consists of a C header file, some build files and documentation.

Several software packages were released at the same time as the LV2 standard announcement. SLV2 0.4.2 is a C library that is used to access the LV2 plugins: "Unlike LADSPA, LV2 is (more or less) designed with the assumption that hosts will use a library to discover/load/use plugins. SLV2 is one such library, which does the Right Thing with as little burden on host authors as possible." The lv2dynparam extension and helper was also announced: "The extension consists of a header describing the extension interface and libraries, one for plugins and one for hosts, to expose functionality in more usable, from programmer point of view, interface."

Three LV2 compatible plugins were also announced by author Nedko Arnaudov, these include the lv2vocoder version 1, Simple Sine Generator 20080109 and zynadd plugin version 1. Arnaudov also released zynjacku version 1, a JACK based GTK2 host for LV2 synthesizers. The success of LV2 will revolve around its adoption by one or more of the major LADSPA applications, as well as the conversion of more LADSPA plugins. Conceptually, LV2 seems like a step forward for the Linux audio plugin architecture.

Comments (1 posted)

System Applications

Database Software

Mogwai: New Release of Mogwai ERDesigner NG (SourceForge)

A new release of Mogwai ERDesigner NG has been announced. "The Mogwai project is proud to announce the redesigned version of the famous Mogwai ERDesigner entity relationship design tool! Mogwai ERDesigner NG is the redesigned version of the prior Mogwai ERDesigner. In its current development phase, it supports visual editing and reverse engineering of the following databases : MySQL, MSSQL, PostgreSQL , Oracle and generic JDBC. The database model is stored as a XML file, so it can be further processed by other tools. The new Release 1.0.1 includes some bugfixes, and is also the base for further development like SQL DDL generation and schema version tracking."

Comments (none posted)

PostgreSQL 8.3 RC2 released

Version 8.3 RC2 of the PostgreSQL DBMS has been announced. "The community testing of RC1 has yielded positive results. We avoided several serious bugs and are now releasing 8.3 RC2. We need the entire community to continue testing to help us get to the final release. Please report your bugs before the end of the month!"

Full Story (comments: none)

Postgres Weekly News

The January 20, 2008 edition of the Postgres Weekly News is online with the latest PostgreSQL DBMS articles and resources.

Full Story (comments: none)

Device Drivers

owfs 2.7p3 released

Version 2.7p3 of owfs is available, this release features performance improvements and C# support. "OWFS -- 1-Wire file system. Use the Dallas 1-Wire and iButton chips with standard linux commands. Create temperature loggers. Monitor everything. OWHTTPD -- same system, only used as a light weight web server. OWFS is also ported to WRT54G and Coldfire".

Comments (none posted)


Samba 4.0.0alpha2 announced

Version 4.0.0alpha2 of Samba has been announced. "Samba 4 is the ambitious next version of the Samba suite that is being developed in parallel to the stable 3.0 series. The main emphasis in this branch is support for the Active Directory logon protocols used by Windows 2000 and above. Samba 4 is currently not yet in a state where it is usable in production environments. Note the WARNINGS below, and the STATUS file, which aims to document what should and should not work."

Comments (none posted)


WifiZoo v1.3 released (minor release)

Version 1.3 of WifiZoo, a tool for passively gathering wifi information, has been announced. "WifiZoo v1.3 is out there. this is a minor release, it basically addresses some minor functionality issues and stuff".

Full Story (comments: none)


OpenBaseMovil J2ME app framework 3.0 released (SourceForge)

Stable version 3.0 of OpenBaseMovil has been announced. "OpenBaseMovil is an enterprise-class J2ME application framework, which includes many features being the most notable the J2ME Relational Database Engine openbasemovil-db, but also the user interface engine that allows you to create your views using XML, and lots of other useful things like local connectivity to Bluetooth devices like bar-code scanners, printers or GPS antennas."

Comments (none posted)

Web Site Development

Midgard 1.8.6 released

Version 1.8.6 of Midgard is out with major bug fixes and enhancements. "Midgard is a capable open source content management system for running mid-to-high-end websites. In addition to the built-in content management features, Midgard also provides a highly object-oriented component architecture for building interactive web applications that integrate seamlessly with the website."

Full Story (comments: 2)


Data Crow: 3.1 has been released (SourceForge)

Version 3.1 of Data Crow, a cross-platform movie, video, book, image, software and music cataloger/DBMS, has been announced. "This latest production version is a major overhaul of the internal system of Data Crow. The changes will not be immediately apparent to the average user however it has caused noticeable positive side effects: increased startup performance, lower memory usage, better performing views."

Comments (none posted)

Desktop Applications

Audio Applications

Amarok Insider on Technical Preview and More (KDE.News)

KDE.News has announced the publication of Issue 11 of the Amarok Insider. "Amarok Insider is the newsletter previously known as Amarok Weekly News (AWN), and is now hosted on the official Amarok website. The new issue covers the freshly released Amarok 2.0 Technical Preview, Amarok's Media Device architecture, the Context View, Playlist, Service Framework, the MS Windows version, recent happenings inside the Amarok team, and much more."

Comments (none posted)

Remote Control Of Ardour With Perl/OSC

Open Sound Control (OSC) support is being added to the Ardour multi-track audio editor. "Jonathan Stowe wrote a Perl module to allow remote control of Ardour with Perl via OSC. At present, OSC control is limited to transport and per-track solo/mute/rec-enable operations. Hopefully with this module there to make testing and development of a remote control application easier, OSC control can be expanded in interesting ways."

Comments (none posted)

wxCommunicator: 1.0.4 released (SourceForge)

Version 1.0.4 of wxCommunicator, a cross platform SIP application, has been announced. "wxCommunicator 1.0.3a has been released. It is compiled with wxWidgets 2.8.7 and sipxtapi SDK built on 21.1.2008. Easier dialing - just enter number, 2 new ringtones, faster call history deletion, audio energy meters."

Comments (none posted)

Desktop Environments

GNOME 2.21.5 released

Version 2.21.5 of GNOME has been announced. "This is the fifth release of the GNOME 2.21.x series, heading towards the stable GNOME 2.22.x release."

Full Story (comments: none)

GARNOME 2.21.5 released

Version 2.21.5 of GARNOME has been announced. "The "more change brings more change" release. We are pleased to announce the release of GARNOME 2.21.5 Desktop and Developer Platform. This is the fifth development release on our road towards GNOME 2.22.0, which will be released in March 2008. This release comes with more features, more fixes, and yet more madness."

Full Story (comments: none)

GNOME Software Announcements

The following new GNOME software has been announced this week: You can find more new GNOME software releases at

Comments (none posted)

The Second Day of the KDE 4.0 Release Event (KDE.News)

Day two of the KDE 4.0 release event is covered by There were presentations on KDE 4 history and roadmap, KOffice, the Qt GPLv3 licensing, Amarok, and more. "Then, Aaron explored what KDE is, and what our community is based on - freedom and openness. Freedom to do work, have fun, and connect with others. Further, Aaron moved on to KDE 4, and discussed the near-future plans and ideas. The vision of KDE 4 is based upon three principles: beauty, accessibility, and functionality."

Comments (none posted)

Qt goes GPLv3

Trolltech has announced that, effective immediately, the Qt libraries will be distributable under version 3 of the GPL. "Trolltech hopes that its move will inspire free software projects to use GPL v3 when programming with Qt." Qt will be dual-licensed, with GPLv2 remaining an option.

Comments (40 posted)

KDE release schedule changes

A new KDE release schedule has been announced: "KDE switches to time-based, 6 months release cycle, KDE 4.1 to be released in July"

Full Story (comments: none)

KDE Software Announcements

The following new KDE software has been announced this week: You can find more new KDE software releases at

Comments (none posted)

Financial Applications

Announcing LedgerSMB 1.2.12

Version1.2.12 of LedgerSMB, a web-based accounting system, has been announced. "The LedgerSMB team has released LedgerSMB 1.2.12 which includes a number of non-critical bug fixes. The major fixes in this release include fixes to warehouse transfer logic, some error handling corner cases, and some fixes to lastcost/avgcost updates."

Full Story (comments: none)

Music Applications

Jackbeat 0.6.2 released

Version 0.6.2 of Jackbeat, an audio sequencer, has been announced. This releases adds several new capabilities, bug fixes and new drum kits.

Full Story (comments: none)

miniloop 0.0 Released

Version 0.0 of miniloop has been announced. "miniloop is a simple live looping program. It can load a number of stereo audio loops of equal length from the disk and loop them in sync with each other, sending each loop to a different pair of JACK audio outputs. These outputs are intended to be subsequently fed into an external software mixer, such as Ardour. For live performance, you will want to control the mixer using a MIDI control surface."

Full Story (comments: none)

Video Applications

Dirac 0.9.0 released

Version 0.9.0 of the Dirac video CODEC has been announced: "Major release complying with the latest Dirac Bytestream Specification Dirac 2.0.0. The specification document can be downloaded from". This release includes numerous enhancements and bug fixes.

Full Story (comments: 2)

Languages and Tools


GCC 4.2.3 Status Report

The January 21, 2008 edition of the GCC 4.2.3 Status Report has been published. "The 4.2 branch is in regression-only mode. Since it has been more than two months since the last release, I propose to prepare 4.2.3-rc1 on Friday 25 January, with either rc2 or the final release on Friday 1 February. Therefore, the branch will go into slush (all changes must be approved by an RM) at 18:00 UTC on Friday, until the release is out."

Full Story (comments: none)

GCC 4.3.0 Status Report

The January 21, 2008 edition of the GCC 4.3.0 Status Report has been published. "We are in Stage 3. When we reach 100 open regressions, we will go to regression-only mode; one of the release managers will announce the exact time the mode is entered. When we approach the 4.3.0 release, we will create a branch, and open Stage 1 for 4.4.0."

Full Story (comments: 1)

Status of GCC 4.3 on HPPA (Debian)

Martin Michlmayr has sent in a report on the status of the GCC 4.3 compiler on the HPPA architecture. "I recently compiled the Debian archive (around 7000 packages that need to be compiled) on HPPA (PA RISC) using trunk to identify new issues before GCC 4.3 is released."

Full Story (comments: none)


Caml Weekly News

The January 23, 2008 edition of the Caml Weekly News is out with new articles about the Caml language.

Full Story (comments: none)


Parrot 0.5.2 released (use Perl)

Version 0.5.2 of the Parrot virtual machine has been announced. "Parrot 0.5.2 Highlights: "make perl6" uses the new pbc_to_exe tool to build a Perl 6 executable. It's still a ways from being a finished implementation of Perl 6, but we're working on that. Come join us! Parrot now has a LOLCODE implementation!"

Comments (none posted)

Perl 6 Design Minutes

The Perl 6 Design Minutes for the January 9, 2008 meeting have been posted. "The Perl 6 design team met by phone on 09 January 2008. Larry, Allison, Patrick, Jerry, Will, Jesse, Nicholas, and chromatic attended."

Comments (none posted)

This Week on perl5-porters (use Perl)

The January 6-12, 2008 edition of This Week on perl5-porters is out with the latest Perl 5 news.

Comments (none posted)


Zend Weekly Summary

The January 3, 2008 edition of the Zend Weekly Summary is out with new articles about PHP. Contents include: "Taint mode decision; late static binding; property type hinting; PECL/core relations; WDSL load error; how to disable the built-in POST handler; a cleanup and maintenance offer; optional scalar type hinting [continued]; string parser BC breakage; ternary shortcut reaches PHP_5_3".

Comments (none posted)


Python-URL! - weekly Python news and links

The January 21, 2008 edition of the Python-URL! is online with a new collection of Python article links.

Full Story (comments: none)


XML Copy Editor: Version introduces Aspell support (SourceForge)

Version of XML Copy Editor, a validating XML editor, has been announced. "Version introduces full Aspell support and XML Schema-based element inspection."

Comments (none posted)

Version Control

ODF-SVN: First odfsvn release: 1.0a1 (SourceForge)

Version 1.0a1 of ODF-SVN has been announced. "odfsvn is a toolset that allow you to manage ODF documents in a subversion repository: it allows simple methods to checkout documents from a repository, update documents to the latest version and commit changes."

Comments (none posted)


Bugzilla C# Proxy: 0.2.0 released (SourceForge)

Version 0.2.0 of Bugzilla C# Proxy has been announced. "Bugzproxy is a C# based assembly that provides access to a Bugzilla server, using the WebService interface of Bugzilla 3.0 or newer (at least 3.0.2 recommended). Works with both MS Windows and Linux/Mono. This release adds several minor changes, a more .net like API, and support for appending a comment to a bug."

Comments (none posted)

SP-Forth: 4.19 released (SourceForge)

Version 4.19 of SP-Forth has been announced. "ANS Forth for Win32 and Linux/x86 (used to compile the following SF projects: acWEB, acFTP, acFreeProxy, acSMTP, Forth-Script) This release features fixes and improvements in kernel, adds more documentation."

Comments (none posted)

Page editor: Forrest Cook
Next page: Linux in the news>>

Copyright © 2008, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds