ref_vfmethod_prefetchProc2 - shekh/VirtualDub2 GitHub Wiki

VirtualDub Plugin SDK 1.2

prefetchProc2 video filter method

prefetchProc2

Lists the input frames required to produce a given output frame.

bool prefetchProc2(const VDXFilterActivation *fa, const VDXFilterFunctions *ff, sint64 frame, IVDXVideoPrefetcher *prefetcher);

Parameters

fa	Pointer to filter activation structure.
ff	Pointer to callback function structure.
frame	Output frame for which to determine inputs.

Thread safety

This method is not thread-safe.

Exceptions

This function must not throw exceptions (see Except()).

Return value

True if handled, false otherwise.

API version requirement

Requires V14 or later.

Default behavior

If omitted or not handled, the source frame is automatically chosen based on the output frame timestamp. This makes the frame numbers equal if the filter does not change the video frame rate.

Remarks

prefetchProc2 is similar to prefetchProc, but with expanded capabilities via the prefetcher argument. These include:

Prefetching more than one source frame.
Associating an arbitrary 64-bit value (a cookie) with each source prefetch.
Specifying a direct association between a source frame and the filter's output, allowing the filter to be bypassed entirely for that frame.