3 title: Understanding Basic Concepts and Terminology
7 This section will help you get acquainted with the basic terminology and
8 concepts associated with Ardour. More detailed information on each aspect
9 of the program is provided in later chapters.
14 An <dfn>Ardour session</dfn> is a container for an entire project. A
15 session may contain an arbitrary number of <dfn>tracks</dfn> and
16 <dfn>busses</dfn> consisting of audio and <abbr title="Musical Instrument
17 Digital Interface">MIDI</abbr> data, along with
18 information on processing those tracks, a mix of levels, and everything
19 else related to the project. A session might typically contain a song, or
20 perhaps an entire album or a complete live recording.
23 Ardour sessions are held in directories; these directories contain one or
24 more <dfn>session files</dfn>, some or all of the audio and MIDI data and
25 a number of other state files that Ardour requires. The session file
26 describes the structure of the session, and holds automation data and
30 Ardour's session file is kept in
31 <abbr title="eXtensible Markup Language">XML</abbr> format, which is
32 advantageous as it is somewhat human-readable, and human-editable in a
33 crisis. Sound files are stored in one of a number of optional formats, and
34 MIDI files as <abbr title="Standard MIDI File">SMF</abbr>.
37 It is also possible for Ardour sessions to reference sound and MIDI files
38 outside the session directory, to conserve disk space and avoid
39 unnecessary copying if the data is available elsewhere on the disk.
42 Ardour has a single current session at all times; if Ardour is started
43 without specifying one, it will offer to load or create one.
46 More details can be found at
47 <a href="/working-with-sessions">Working With Sessions</a>.
52 A <dfn>track</dfn> is a concept common to most
53 <abbr title="Digital Audio Workstation">DAWs</abbr>, and also used in
54 Ardour. Tracks can record audio or MIDI data to disk, and then replay
55 it with processing. They also allow the audio or MIDI data to be edited
56 in a variety of different ways.
59 In a typical pop production, one might use a track each for the kick
60 drum, another for the snare, more perhaps for the drum overheads and
61 others for bass, guitars and vocals.
64 Ardour can record to any number of tracks at one time, and then play
65 those tracks back. On playback, a track's recordings may be processed by
66 any number of plugins, panned, and its level altered to achieve a
70 A track's type is really only related to the type of data that it stores
71 on disk. It is possible, for example, to have a MIDI track with a
72 synthesizer plugin which converts MIDI to audio. Even though the track
73 remains MIDI (in the sense that its on-disk recordings are MIDI), its
74 output may be audio-only.
77 More details can be found at
78 <a href="/working-with-tracks">Working With Tracks</a>.
81 <h2 id="busses">Busses</h2>
83 <dfn>Busses</dfn> are another common concept in both DAWs and hardware
84 mixers. They are similar in many ways to tracks; they process audio or
85 MIDI, and can run processing plugins. The only difference is that their
86 input is obtained from other tracks or busses, rather than from disk.
89 One might typically use a bus to collect together the outputs of related
90 tracks. Consider, for example, a 3-track recording of a drum-kit; given
91 kick, snare and overhead tracks, it may be helpful to connect the output
92 of each to a bus called "drums", so that the drum-kit's level can be set
93 as a unit, and processing (such as equalisation or compression) can be
94 applied to the mix of all tracks. Such buses are also called
100 A track may contain many segments of audio or MIDI. Ardour contains
101 these segments in things called <dfn>regions</dfn>, which are
102 self-contained snippets of audio or MIDI data. Any recording pass, for
103 example, generates a region on each track that is enabled for recording.
104 Regions can be subjected to many editing operations; they may be moved
105 around, split, trimmed, copied, and so on.
108 More details can be found at
109 <a href="/working-with-regions">Working With Regions</a>.
114 The details of what exactly each track should play back is described by a
115 <dfn>playlist</dfn>. A playlist is simply a list of regions; each track
116 always has an active playlist, and can have other playlists which can be
117 switched in and out as required.
120 More details can be found at
121 <a href="/working-with-playlists">Working With Playlists</a>.
126 Ardour allows you to process audio and MIDI using any number of
127 <dfn>plugins</dfn>. These are external pieces of code, commonly seen as
128 VST plugins on Windows or AU plugins on Mac OS X. Ardour supports
129 the following plugin standards:
131 <dl class="wide-table">
132 <dt><abbr title="Linux Audio Developers' Simple Plugin API">LADSPA</abbr></dt>
133 <dd>the first major plugin standard for Linux. Many LADSPA plugins are
134 available, mostly free and open-source.</dd>
135 <dt><abbr title="LADSPA Version 2">LV2</abbr></dt>
136 <dd>the successor to LADSPA. Lots of plugins have been ported from
137 LADSPA to LV2, and also many new plugins written.</dd>
138 <dt><abbr title="Virtual Studio Technology">VST</abbr></dt>
139 <dd>Ardour supports VST plugins that have been compiled for Linux.</dd>
140 <dt><abbr title="Audio Units">AU</abbr></dt>
141 <dd>Mac OS X versions of Ardour support AudioUnit plugins.</dd>
144 Ardour has some support for running Windows VST plugins on Linux, but
145 this is rather complicated, extremely difficult for the Ardour
146 developers to debug, and generally unreliable, as it requires to run a
147 large amount of Windows code in an emulated environment.<br />
148 If it is at all possible, you are strongly advised to use native
149 LADSPA, LV2 or Linux VST plugins on Linux, or AU on Mac OS X.
152 More details can be found at
153 <a href="/working-with-plugins">Working With Plugins</a>.