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Property
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Description
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Class
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Superclass
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Subclass
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Definition
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An instance of this DRM class is a single case of the existence of
a <DRM Sound> within
a given transmittal, including variations or specialization unique to
that case. A <DRM Sound Instance> can represent
environmental audio, region-based audio, or spatialized audio.
Environmental audio is audio that is non-localized and non-attenuated.
It is constant over the entire transmittal. Environmental audio can be
thought of as “background” sound. It has no
<DRM 3D Location>,
<DRM Perimeter Data>, or
<DRM Sound Volume>. An example would be the
constant sound of rainfall over an entire transmittal.
Region-based audio is similar to environment audio, except that it is
constant over either an areal region (if it has a
<DRM Perimeter Data>) or
a three dimensional volume (if it has a
<DRM Sound Volume>). Region-based
audio is non-localized, but it may be attenuated to support fade out
at the boundary of the region. (See examples for
<DRM Perimeter Data>,
<DRM Sound Volume>).
Spatialized audio may be either two dimensional or three dimensional.
The method of rendering spatialized audio is left to the consuming
application. In this case, a <DRM 3D Location>
is associated with the <DRM Sound Instance>
if spatialized audio is desired.
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Class diagram
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Figure 6.285 —
DRM_Sound_Instance
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Inherited field elements
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Field name
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Range
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Field data type
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None |
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Field elements
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Associated to (one-way) (inherited) |
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Associated to (one-way) |
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Associated by (one-way) (inherited) |
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Associated by (one-way) |
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Associated with (two-way) (inherited) |
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Associated with (two-way) |
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Composed of (two-way) (inherited) |
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Composed of (two-way) |
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Composed of (two-way metadata) (inherited) |
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Composed of (two-way metadata) |
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Component of (two-way) (inherited) |
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Component of (two-way) |
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Constraints
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Clarifications
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1
This is the default / active state of the given
<DRM Sound>, where
TRUE indicates on and
FALSE indicates off.
2
This is the <DRM Sound> being instanced.
3
This is used for spatialized audio.
4
This is used to define the starting distance at which a fade to off
should begin and an ending distance at which the fade to off
should be complete.
The distance in the <DRM Fade Range> is the
range to a <DRM 3D Location>, which in turn is
- the centre of the <DRM Sound Volume> of the
<DRM Sound Instance>, if present.
- the centre of the <DRM Perimeter Data> of
the <DRM Sound Instance>, if present.
If no <DRM Fade Range> is present, no attenuation
is to be performed, which implies instantaneous
on / off transitions at the borders of the
<DRM Perimeter Data> and
<DRM Sound Volume>.
5
This defines an area within which the <DRM Sound>
is to be active.
6
This defines a volume within which the <DRM Sound>
is to be active.
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Example(s)
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Given a <DRM Geometry Model Instance>
of an M1, a <DRM Sound Instance> for the
<DRM Geometry Model Instance> uses the
<DRM 3D Location> of the M1 for the location
of the audio.
Given a <DRM Geometry Model Instance>
of an F16, a <DRM Sound Instance> for the
<DRM Geometry Model Instance>
specifies a unique <DRM 3D Location> for the audio
in order to simulate propagation of sound delay
(one would hear the audio in a slightly different location
than one would see the F16).
Create a 2-stage sound effect for an engine. The
stages are “engine crank” and “engine running”.
The first <DRM Sound> is instanced by a
<DRM Sound Instance> with a
<DRM Time Interval> from 0,0 to
1,5 seconds.
The second <DRM Sound> is a looped sound, and is
instanced by a <DRM Sound Instance>
with a start delay (via the <DRM Time Interval>
of 1,5 seconds, and no end time. The application
would set the
<DRM Sound Instance Control Link>
instances of both <DRM Sound Instance> instances
to “on” to
start the sound, at which point the crank sound would play for
1,5 seconds,
followed by the (looped) engine running sound. The engine running sound
would continue to play until the application set the
<DRM Sound Instance Control Link>
for the engine running sound to “off”.
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