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>Chapter 16. Supporting Dynamic Parameters</H1
><P
> Sometimes object properties are not powerful enough to control the
parameters that affect the behaviour of your element. When this is the case
you can expose these parameters as Dynamic Parameters which can be
manipulated by any Dynamic Parameters aware application.
</P
><P
> Throughout this section, the term <SPAN
CLASS="emphasis"
><I
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>dparams</I
></SPAN
> will be used
as an abbreviation for "Dynamic Parameters".
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>16.1. Comparing Dynamic Parameters with GObject Properties</A
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> Your first exposure to dparams may be to convert an existing element from
using object properties to using dparams. The following table gives an
overview of the difference between these approaches. The significance of
these differences should become apparent later on.
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> </TH
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>Object Properties</TH
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>Dynamic Parameters</TH
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><TD
><SPAN
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><I
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>Parameter definition</I
></SPAN
></TD
><TD
>Class level at compile time</TD
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>Any level at run time</TD
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><TD
><SPAN
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><I
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>Getting and setting</I
></SPAN
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><TD
>Implemented by element subclass as functions</TD
><TD
>Handled entirely by dparams subsystem</TD
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><TD
><SPAN
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><I
CLASS="emphasis"
>Extra objects required</I
></SPAN
></TD
><TD
>None - all functionality is derived from base GObject</TD
><TD
>Element needs to create and store a <TT
CLASS="filename"
>GstDParamManager</TT
> at object creation</TD
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>Frequency and resolution of updates</I
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>Object properties will only be updated between calls to _get, _chain or _loop</TD
><TD
>dparams can be updated at any rate independant of calls to _get, _chain or _loop up to sample-level accuracy</TD
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