IAMVideoCompression::OverrideKeyFrame method (strmif.h)

Article
02/22/2024

[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The OverrideKeyFrame method instructs the filter to compress a particular frame as a key frame.

Syntax

HRESULT OverrideKeyFrame(
  [in] long FrameNumber
);

Parameters

[in] FrameNumber

Specifies the frame number. The first frame that the filter delivers is numbered zero.

Return value

Returns an HRESULT value. Possible values include the following.

Return code	Description
S_OK	Success.
E_NOTIMPL	Not implemented.

Remarks

If the filter supports this method, you can use it to override the normal key-frame distribution for a particular frame. After the filter creates a key frame, it might reset its count to determine when the next key frame should occur. For example, if the key-frame rate is 10, and an application uses this method to force frame 5 as a key frame, the filter might wait another 10 frames (until frame 15) before it creates the next key frame.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	strmif.h (include Dshow.h)
Library	Strmiids.lib