User Manual

12 User Manual v 1.62
UNVEIL
Notes On Formats
Plug-In Formats and Channel
Layouts
AudioSuite in ProTools
As you will have noticed, we install separate mono/stereo and 8-channel versions for some
formats. Why is that? Here’s a run-down on the formats and why we may or may not have
multiple plug-in builds for them.
AudioUnits: This format theoretically allows having one plug-in build that works for any
channel count. However, in some hosts, the ability of a plug-in to have more than two channels
will prevent using multi-mono instances for multi-channel scenarios. Also, some hosts are not
capable of inserting multi-mono instances to create a multi-channel instance. Hence we need
two separate plug-ins to cater for all scenarios. (The advantage of multi-mono is that it allows
you to have separate settings for the individual channels).
VST 2.4: The VST 2.4 standard allows plug-ins to have a large number of channels under the
hood, but activating only the number actually required by the channelstrip/bus the plug-in is
inserted into. However, some hosts will always activate all the “under-the-hood” channels,
regardless of whether they are needed or not. This results in a very large CPU overhead if all
you want to do is process one or two channels. Also, VST 2.4 does not easily allow using multi-
mono instances for multi-channel use. Hence, it makes sense to have separate mono/stereo
and 8-channel versions of the plug-in.
RTAS & AAX: RTAS and AAX allow using plug-ins in multi-mono configurations under all
circumstances. As using multi-mono is actually preferable, as ProTools is able to run the multi-
mono channels on separate cores, these formats need only one plug-in build.
In ProTools, the AAX plug-in allows being used as AudioSuite for offline processing, including
real-time preview.