IAMVideoCompression::OverrideKeyFrame method (strmif.h)
[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 |
|---|---|
|
Success. |
|
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 |