Posts

Suil 0.6.16 has been released. Suil is a library for loading and wrapping LV2 plugin UIs. For more information, see http://drobilla.net/software/suil.

Changes:

• Fix crashes and resizing for X11 in Qt (patch from Rui Nuno Capela)
• Fix suil_instance_extension_data() for UIs with NULL extension_data

Jalv 1.4.2 has been released. Jalv is a simple but fully featured LV2 host for Jack which exposes plugin ports to Jack, essentially making any LV2 plugin function as a Jack application. For more information, see http://drobilla.net/software/jalv.

Changes:

• Add command-line option to control UI update frequency
• Fix crash when running "jalv" with bad command line arguments
• Fix default setting for non-sequential enumeration ports (patch from Robin Gareus)
• Fix parameter changes with Qt UI
• Fix potential crash with UIs and debug printing
• Nicer printing of atom messages with -d
• Support rsz:minimumSize for atom and event ports
• Upgrade to waf 1.7.11
• Work around Gtk bug for labels on sliders (patch from Robin Gareus)

Suil 0.6.14 has been released. Suil is a library for loading and wrapping LV2 plugin UIs. For more information, see http://drobilla.net/software/suil.

Changes:

• Add support for new LV2 idle interface
• Lower dependency from Gtk 2.24 introduced in 0.6.12
• Print system error message if module fails to load
• Support resizing for X11 in Gtk (patch from Robin Gareus)
• Upgrade to waf 1.7.11

I found some time today to make Ingen's support for running as an LV2 more solid. I have posted about this before, but it now works at RT appropriate buffer sizes, and several other bugs have been fixed. Here's the obligatory contrived screenshot:

People are sometimes confused about how Ingen works as an LV2 (I need to write proper documentation One of These Days): you don't load an "Ingen" plugin so much (it wouldn't do anything), as you save an Ingen graph as an LV2 plugin. The idea is that Ingen is a tool for visually building plugins. Since LV2 does not support dynamically adding ports, it's easiest to do your building as a Jack app, so the basic work flow is something like:

1. Run Ingen as a Jack app: ingen -eg
2. Build a graph, adding ports, plugins, etc.
3. Save the graph to somewhere in your LV2_PATH, e.g. ~/.lv2 (which happens to be the default directory of the save dialog for this reason).
4. Voila, your graph should now show up in any LV2 host (its URI will simply be its local filesystem path, unless you explicitly set a stable one). You can check with lv2ls.

There is no export or compilation involved, Ingen's native format is LV2 compatible (graphs are always saved in the same format). If you saved a graph elsewhere you can simply copy it to ~/.lv2 to use it as a plugin, though for now you may have to create or fix the symlink to the engine binary manually to do this.

Note that you can edit the graph while it's running as an LV2 plugin, including adding new nodes and connections, you just can't add top-level ports because the host doesn't know about them. There is still some work to be done polishing this up to be ready for prime-time, but for the brave, it's more or less good to go.

Jalv 1.4.0 has been released. Jalv is a simple but fully featured LV2 host for Jack which exposes plugin ports to Jack, essentially making any LV2 plugin function as a Jack application. For more information, see http://drobilla.net/software/jalv.

Changes:

• Add menu bar and pass parent widget in Qt version for true UI embedding
• Add spinbuttons for precisely setting control values
• Group controls under headings if port group information is available
• Make URI map thread-safe, fixing occasional crashes for plugins with UIs
• Send time information to plugin when Jack tempo changes
• Support state:loadDefaultState
• Update to waf 1.7.8 and autowaf r90
• Use a more efficient dense layout for controls

Suil 0.6.12 has been released. Suil is a library for loading and wrapping LV2 plugin UIs. For more information, see http://drobilla.net/software/suil.

Changes:

• Fix compilation on BSD
• Fix crash when a broken UI returns a NULL descriptor
• Fix key events for X11 in Gtk without using a troublesome event filter

Lilv 0.16.0 has been released. Lilv is a C library to make the use of LV2 plugins as simple as possible for applications. For more information, see http://drobilla.net/software/lilv.

Changes:

• Add lilv_nodes_merge()
• Add lilv_world_ask() for easily checking if a statement exists
• Add lilv_world_get() and lilv_port_get() for easily getting one value
• Add va_list variant of lilv_plugin_get_num_ports_of_class()
• Correctly depend on serd at build time (fix compilation in odd cases)
• Disable timestamps in HTML documentation for reproducible build
• Fail gracefully when lilv_state_new_from_string() is called on NULL
• Fix several plugin functions that failed to load data if called first
• Ignore state ports with no value instead of printing an error
• Make lilv_plugin_get_port_by_designation() return a const pointer
• Make state loading functions fall back to lv2:default for port values, so a plugin description can be loaded as default state
• Require a URI for lilv_state_to_string() and fail gracefully otherwise
• Support atom:supports in lilv_port_supports_event()
• Update to waf 1.7.8 and autowaf r90 (install docs to versioned directory)
• lilvmm.hpp: Add several missing methods
• lilvmm.hpp: Support varargs for Plugin::get_num_ports_of_class()

Sratom 0.4.2 has been released. Sratom is a small library for serialising LV2 atoms to and from RDF, for converting between binary and text or storing in a model. For more information, see http://drobilla.net/software/sratom.

Changes:

• Disable timestamps in HTML documentation for reproducible build
• Fix memory leaks
• Fix serialisation of nested tuples
• Update to waf 1.7.9 and autowaf r90 (install docs to versioned directory)
• Use new sord API to clean up and shrink code

Today I implemented better UI generation for LV2 plugin controls in Jalv, particularly grouping controls under headings which makes a big difference. Unfortunately few plugins group their controls currently, but hopefully more host support will provide the incentive to do so.

Other improvements:

• Added a spinbutton to slider controls for precisely setting values numerically
• Much more efficient layout to pack more controls on the screen at once
• Support for named scale points ("ticks") on non-enumeration ports

Here is the UI generated for Amsynth (after I added the necessary metadata):

Still pretty utilitarian, but much more usable, which is the important thing. Of course, this plugin is quite large, and has a pretty good custom UI, but I happened to be polishing up its metadata anyway and the controls group nicely so I used it as my test case.

Maybe some day this code will get smarter and evolve into a library that can be used by other Gtk hosts. Better group layout is the obvious "next level" advancement, a flat linear list of controls is pretty limited. Unfortunately there's no stock Gtk container which can do text-like reflow, which would be ideal. Perhaps a simpler scheme based on a maximum reasonable width for a controller would do, where the table will expand to have more columns if the window is wide enough for several.

Most of the metadata required to generate a good UI is also useful for other purposes, for example groups make building a decent menu of many controls feasible (e.g. to add automation lanes in Ardour), and some types of host UIs like a modular patcher inherently need to generate their own "UI" of sorts.

Good metadata is not at odds with custom UIs, they each have their uses, but it is important to remove the burden of custom UIs for simple plugins with just a few controls that really don't need them. It's a waste of that most precious of all resources - developer time - to have to code UIs for a few sliders and toggles. Hopefully better host generated UIs and support for more advanced controls like file selectors free up developers to spend more time making useful plugins and less time wrestling with GUI toolkits.

It is, after all, all about the sound.

LV2 has been slowly but surely moving towards message-based control to overcome the limitations of static ports. The required low level facilities have been available for a while now, but the lack of a standard way to document message-based parameters and host UI support has been a sticking point. One particularly pressing need is file parameters. The current sample example has a stop-gap UI to enable sample loading, but parameters really should be host controllable and simple plugins should not need a custom UI to be usable. Today I did some work towards resolving that situation.

Here is ConvoLV2 running in Jalv:

Note this is the built-in UI generated by Jalv and not a custom plugin UI. Unlike traditional LADSPA style controls, the impulse parameter is not a port, but is set by sending a message to an event port. The plugin lists parameters with the new patch:writable property, so the host knows which controls to display (or which parameters it can automatically set). Parameters are described as normal RDF properties, so any existing property can be used, or plugins can define them as needed in their data files (don't let the "RDF" scare you, the description of a Property is as simple as LV2 ports). One nice advantage of this over ports is that a project can describe a parameter once and use it in many plugins, without having to describe the parameter every time. This really adds up when you have hundreds of plugins with, say, an identical gain parameter.

These conventions will be established in the next LV2 release (1.4.0), and the sampler example will serve as a test case. When host support becomes established, we can also move towards using messages for numeric parameters, which will finally allow for dynamic parameters, control ramps, and so on.