Functions
Called by the System
The system
calls three different kinds of application-defined functions. Callback
functions are functions in your application that the system calls in response
to a request made by an application. Hook procedures help an application handle
the customization of dialog boxes. A driver procedure is an application s
implementation of its own codec, converter, or filter.
The callback
functions have the following names:
acmDriverEnumCallback
acmFilterEnumCallback
acmFilterTagEnumCallback
acmFormatEnumCallback
acmFormatTagEnumCallback
acmStreamConvertCallback
Most of the
enumeration functions in the ACM use callback functions. For example, when you
call an enumeration function, the ACM enumerates the items by repeatedly
calling the application through the callback function.
Some
functions cannot be called from within these callback functions. Functions that
cannot be called manipulate internal ACM structures that are used by the
enumeration functions. The following functions should not be called from within
a callback function:
acmDriverAdd
acmDriverPriority
acmDriverRemove
The system
calls the following functions to help an application handle the customization
of dialog boxes:
acmFilterChooseHookProc
acmFormatChooseHookProc
The following
function is specified as a prototype that allows an application to use a
customized codec, converter, or filter. A function conforming to this prototype
may be passed as an argument to the acmDriverAdd function.
acmDriverProc