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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 Location 3D>,
<DRM Perimeter Data>, or
<DRM Sound Volume> components. 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> instance) or
a three dimensional volume (if it has a
<DRM Sound Volume> instance). 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 Location 3D>
instance
is associated with the <DRM Sound Instance>
instance
if spatialized audio is desired.
The active_sound_value
specifies the default/active state of the given
<DRM Sound> instance, where
TRUE indicates on and
FALSE indicates off.
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Clarifications
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1
This specifies the sound being instanced.
2
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>
instance is the
range to a <DRM Location 3D>
instance, which in turn is
- the centre of the <DRM Sound Volume>
instance of the
<DRM Sound Instance> instance, if present.
- the centre of the <DRM Perimeter Data>
instance of
the <DRM Sound Instance> instance, if present.
If no <DRM Fade Range> instance is present, no attenuation
is to be performed, which implies instantaneous
on/off transitions at the borders specified by the
<DRM Perimeter Data> and
<DRM Sound Volume> instances.
3
This is used for spatialized audio.
4
This defines an area within which the <DRM Sound>
instance
is to be active.
5
This defines a volume within which the <DRM Sound>
instance
is to be active.
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Class diagram
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Figure 6.289 —
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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Example(s)
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Given a <DRM Geometry Model Instance>
instance
of a truck, a <DRM Sound Instance>
instance for the
<DRM Geometry Model Instance>
instance uses the
<DRM Location 3D> instance of the
truck for the location
of the audio.
Given a <DRM Geometry Model Instance>
instance
of a fighter jet, a <DRM Sound Instance>
instance for the
<DRM Geometry Model Instance>
instance
specifies a unique <DRM Location 3D>
instance 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 fighter jet).
Create a two-stage sound effect for an engine. The
stages are “engine crank” and “engine running”.
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The first <DRM Sound> instance is instanced by a
<DRM Sound Instance> instance with a
<DRM Time Interval> instance from 0,0 to
1,5 seconds.
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The second <DRM Sound> instance is a looped sound, and is
instanced by a <DRM Sound Instance>
instance
with a start delay (via the <DRM Time Interval>
instance
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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