IAMDroppedFrames interface (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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 IAMDroppedFrames interface retrieves performance information from a video capture filter, including how many frames were dropped and how many were delivered. Applications can use this interface to determine capture performance at run-time.
Inheritance
The IAMDroppedFrames interface inherits from the IUnknown interface. IAMDroppedFrames also has these types of members:
Methods
The IAMDroppedFrames interface has these methods.
| IAMDroppedFrames::GetAverageFrameSize The GetAverageFrameSize method retrieves the average size of the frames that the filter has captured. |
| IAMDroppedFrames::GetDroppedInfo The GetDroppedInfo method retrieves an array of frame numbers that were dropped. |
| IAMDroppedFrames::GetNumDropped The GetNumDropped method retrieves the total number of frames that the filter has dropped since it started streaming. |
| IAMDroppedFrames::GetNumNotDropped The GetNumNotDropped method retrieves the total number of frames that the filter has delivered since it started streaming. |
Remarks
Some filters that expose this interface do not implement the GetDroppedInfo or GetAverageFrameSize method.
For Windows Driver Model (WDM) devices, the WDM Video Capture Filter automatically exposes this interface if the WDM driver supports the PROPSETID_VIDCAP_DROPPEDFRAMES property set. For more information, see the Windows Driver Kit (WDK) documentation.
The number of dropped frames is reported by the capture driver. This information is not directly correlated with any particular media sample, so it is not accurate on a per-frame basis, although it should be accurate over time.
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) |