ref_vfmethod_startProc - shekh/VirtualDub2 GitHub Wiki

VirtualDub Plugin SDK 1.2

startProc video filter method

startProc

Prepares a filter instance for processing video frames.

int startProc(VDXFilterActivation *fa, const VDXFilterFunctions *ff);

Parameters

fa	Pointer to filter activation structure.
ff	Pointer to callback function structure.

Thread safety

This method is not thread-safe.

Exceptions

Exceptions may be thrown from this function (see Except()).

Return value

Zero if successful, non-zero on unknown failure.

Default behavior

If omitted, no default action is taken.

Remarks

This function is the ideal place for memory allocation and table initialization to take place. Filter chain startup is comparatively rare, so this is the ideal place to put lengthy precomputation.

If you allocate a number of resources in this function, and one of the allocations fails, you do not have to release the resources that were allocated successfully. VirtualDub always calls endProc for all filters on failure, so you can free the resources there.