composite_sampler(1) audio sampler/synth plugin (LV2)

DESCRIPTION

The Composite sampler is an audio plugin (LV2) that provides a simple sampling engine. It is identified by the URI "http://gabe.is-a-geek.org/composite/plugins/sampler/1"

PORTS

The sampler includes the following ports:

Name LV2 Port Type Flow Description
Left out_left AudioPort Output Left stereo channel output
Right out_right AudioPort Output Right stereo channel output
MIDI midi EventPort Input Main MIDI Input
Volume volume ControlPort Input Master volume [0.0-1.0]

CONTROLLING THE SAMPLER

The primary way to control the sampler is over MIDI. See composite_midi(7) for complete documentation on the MIDI implementation.

DRUMKITS

The drumkits for Composite are the same as for Hydrogen. To reuse your Hydrogen drumkits, copy or symlink them to $HOME/.composite/data/drumkits/. You can create and edit drumkits with composite-gui (or Hydrogen).

PRESETS

The sampler responds to MIDI Program Change events. Based on the event that it receives, it will load up another file (e.g. a drumkit). This is how you can select the drumkit that you wish to use.

The presets are defined in a file $HOME/.composite/data/presets/default.xml. For the sampler plugin, you can override this by using default-presets.xml, but at the current time there is no need to. When you first load the sampler, it will check for this file. If it doesn't exist, it will create one based on all your user drumkits.

The presets file is a simple XML file that allows you to define MIDI banks, and assign different resources for each program change. An example file is as follows:

<?xml version="1.0"?>
<T:tritium xmlns:T="http://gabe.is-a-geek.org/tritium/xml/1/">
    <T:presets>
        <T:bank coarse="0" fine="0">
            <T:program>
                <T:midi_number>0</T:midi_number>
                <T:resource>tritium:drumkits/GMkit</T:resource>
            </T:program>
            <T:program>
                <T:midi_number>1</T:midi_number>
                <T:resource>tritium:drumkits/TR808EmulationKit</T:resource>
            </T:program>
        </T:bank>
    </T:presets>
</T:tritium>

You can define several <bank> elements for the MIDI banks. The attributes coarse and fine correspond to the MIDI CC's 0 and 32. Each <program> section is a preset. The <midi_number> corresponds to the number in the PC message.

The <resource> element holds a URI/URL to the thing you want loaded. This will typically be a drum kit, but can be any kind of file that Composite supports (like a .h2song, .h2pattern, etc.). The sampler will do the Right Thing. (For example, when loading an .h2song, the drumkit stored in the song will be loaded.) The URL's supported are file://, tritium:, and file names.

The tritium: scheme is designed to create portable URL's to things like drum kits. For example, the URL "tritium:drumkits/GMkit" will load the drumkit "GMkit", whether it's installed in the user directory ($HOME/.composite/data/drumkits/GMkit/drumkit.xml) or in the system directory (/usr/share/composite/data/drumkits/GMkit/drumkit.xml).


Note

The XML namespace declaration "http://gabe.is-a-geek.org/tritium/xml/1/" is not optional.

LV2 EXTENSIONS

This plugin uses the following extensions, and they must be supported by any program (host) that wishes to use this plugin. If the host does not support them, the plugin will fail to load.

• Events <http://lv2plug.in/ns/ext/event#>

• Midi Events <http://lv2plug.in/ns/ext/midi#MidiEvent>

FILES

/usr/share/composite/data/ --- This is the main folder where system data (drumkits, presets, etc.) are stored for Composite and Composite Sampler.

$HOME/.composite/data/ --- This is the main folder where user data (drumkits, presets, etc.) are stored for Composite and Composite Sampler.

$HOME/.composite/data/drumkits/ --- This is the main folder where user drumkits are stored. Each drumkit has its own folder, and each folder has a file 'drumkit.xml' that describes the drumkit.

$HOME/.composite/data/presets/default.xml --- This is the default presets file for Composite. If it does not exist, it will be created automatically using all of your installed drumkits.

$HOME/.composite/data/presets/default.xml --- This is the default presets file for Composite. If it does not exist, it will be created automatically using all of your installed drumkits.

$HOME/.composite/data/presets/default-plugin.xml --- This is the default presets file for the Composite Sampler. If it does not exist, then $HOME/.composite/data/presets/default.xml is used.

KNOWN BUGS

Loading a .h2song through the presets is not happening in a real-time safe manner. Loading drumkits works fine.

AUTHOR

Gabriel M. Beddingfield

<[email protected]>