ref_iface_IVDXVideoPrefetcher_PrefetchFrameDirect

VirtualDub Plugin SDK 1.2

IVDXVideoPrefetcher interface

IVDXVideoPrefetcher:: PrefetchFrameDirect

Requests that a frame be copied from an upstream source.

void PrefetchFrameDirect(sint32 srcIndex, sint64 frame);

Parameters

srcIndex	Source stream index to prefetch from. Must be zero.
frame	Frame number to prefetch.

Thread safety

This method is not thread-safe.

Errors

Errors may not be returned from this function (see SetError()).

Remarks

This operates the same as the PrefetchFrame() function, except that it also adds a hint that the frame is passed through unmodified by the filter. This allows the host to skip the filter entirely. One benefit is higher performance, and another is that recompression can be skipped for those frames.

Since the direct/non-direct decision must be made at prefetch time and not when processing video data, the general uses for this function are for a filter that either works off of analysis data produced by a previous pass or has configuration parameters that restrict processing to a specific set of frames.

Direct prefetches are only a hint. The host can still call the filter as if the frame were prefetched normally. In this case, the filter should copy the frame unmodified from source to destination.

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Copyright (C) 2007-2012 Avery Lee.