IMixerOCXNotify::OnDataChange method (mixerocx.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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 OnDataChange method notifies the client when the video rectangle's aspect ratio or size, or the display palette, has changed.
Syntax
HRESULT OnDataChange(
[in] ULONG ulDataFlags
);
Parameters
[in] ulDataFlags
Flag indicating which set of data has changed. The following flags are defined.
| Flags | Description |
|---|---|
| MIXER_DATA_ASPECT_RATIO (0x00000001) | Picture aspect ratio. |
| MIXER_DATA_NATIVE_SIZE (0x00000002) | The video stream's native size changed. |
| MIXER_DATA_PALETTE (0x00000004) | The video palette changed. |
Return value
If the method succeeds, it returns S_OK.
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 | mixerocx.h |
| Library | Strmiids.lib |