number of tracks or busses in Ardour. This is a lot like doing some of the
processing with a chain of guitar pedals, then feeding the signal to an Aux In
port on a mixing console or an input port on a multi-effects digital
- pedalboard. The rationale for pre-processing with I/O plugins is that it's a
- more lightweight way to do it as compared to busses.
+ pedalboard.
+</p>
+
+<p>
+ The rationale for pre-processing with I/O plugins is that it's a more
+ lightweight way to do it as compared to busses. Much of that is because busses
+ have automatable parameters such as fader and panner positions, as well as
+ plugins' parameters. Evaluating parameter automation (even when there's none)
+ adds additional load to the CPU. However I/O plugins are not automatable, so
+ there's no evaluation happening. As far as Ardour is concerned, they are
+ almost like JACK audio server clients running alongside Ardour.
</p>
<p>
IP to a receiver for broadcasting.
</p>
+<figure>
+ <img style="width:50%;" width="50%" src="/images/io-plugins-ndi-input.png" alt="NDI Input plugin loaded as a pre-processing I/O plugin">
+ <figcaption>NDI Input plugin loaded as a pre-processing I/O plugin</figcaption>
+</figure>
+
<p>
It's also possible to use the post-processing section to load plugins for room
correction or signal analysis (VU meters, spectrum analyzers etc.).
<img style="width:50%;" width="50%" src="/images/io-plugins-new-track-from-io-plugin.png" alt="New track connected to an I/O plugin">
<figcaption>New track connected to an I/O plugin</figcaption>
</figure>
+
+<p>
+ On the <kbd class="window">Audio Connections</kbd> dialog, the ports of pre-
+ and post-process plugins are listed on dedicated tabs
+ (<kbd class="tab">I/O Pre</kbd> and <kbd class="tab">I/O Post</kbd>),
+ separately from all other ports.
+</p>
+
+<figure>
+ <img style="width:50%;" width="50%" src="/images/io-plugins-in-audio-connections.png" alt="I/O Plugins in the Audio Connections dialog">
+ <figcaption>I/O Plugins in the Audio Connections dialog</figcaption>
+</figure>