IWMReaderAdvanced::GetStatistics method (wmsdkidl.h)
[The feature associated with this page, Windows Media Format 11 SDK, is a legacy feature. It has been superseded by Source Reader and Sink Writer. Source Reader and Sink Writer have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use Source Reader and Sink Writer instead of Windows Media Format 11 SDK, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]
The GetStatistics method retrieves the current reader statistics.
Syntax
HRESULT GetStatistics(
[in, out] WM_READER_STATISTICS *pStatistics
);
Parameters
[in, out] pStatistics
Pointer to a WM_READER_STATISTICS structure.
Return value
The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.
| Return code | Description |
|---|---|
|
The method succeeded. |
|
pStatistics is NULL, or the cbSize member of pStatistics is not set to the size of WM_READER_STATISTICS. |
|
The method is unable to allocate memory for an internal object. |
|
The reader object has not opened a file yet. |
Remarks
The WM_READER_STATISTICS structure must be supplied by the application. The cbSize data member must be set before the structure is passed to the method. The rest of the members will be set by this method.
As with any method, too many calls can affect performance. The actual performance impact is machine-dependent. Using the GetStatistics method for each sample is not recommended. The Microsoft Windows Media Encoder pulls the data once per second, which results in a manageable amount of data being passed.
The GetStatistics method is not recommended for a callback method like IWMReaderCallback::OnSample. In general, such calls have the potential to lead to deadlocks.
To determine the connection bandwidth before receiving a sample, the IWMReaderNetworkConfig::GetConnectionBandwidth method is the recommended method. The GetStatistics method has more overhead.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 2000 Professional [desktop apps only],Windows Media Format 7 SDK, or later versions of the SDK |
| Minimum supported server | Windows 2000 Server [desktop apps only] |
| Target Platform | Windows |
| Header | wmsdkidl.h (include Wmsdk.h) |
| Library | Wmvcore.lib; WMStubDRM.lib (if you use DRM) |