IWMReaderNetworkConfig2::SetEnableThinning method (wmsdkidl.h)

Article
4/26/2023

[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 It has been superseded by Source Reader and Sink Writer.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 SetEnableThinning method enables or disables Intelligent Streaming. Intelligent Streaming is the communication between the reader and the streaming server that enables the server to change the content sent based on available bandwidth.

Syntax

HRESULT SetEnableThinning(
  [in] BOOL fEnableThinning
);

Parameters

[in] fEnableThinning

Specify True to enable thinning, or False to disable thinning.

Return value

The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.

Return code	Description
S_OK	The method succeeded.

Remarks

With Intelligent Streaming enabled, the reader responds to insufficient bandwidth by requesting that the server reduce the bit rate by using one of the following techniques. If one technique does not solve the problem, the reader will try the next one:

If the file is encoded using multiple bit rates (MBR), the first step the reader takes to rectify insufficient bandwidth is to request a lower bit rate version of streams.
If the file is not MBR, or if using a lower bit rate stream does not reduce the bandwidth requirements enough, the reader requests that the server thin the video streams. This means that the server reduces the frame rate of the video being streamed.
If thinning the video streams does not reduce the bandwidth requirements enough, the reader requests that the server stop sending video streams.

If Intelligent Streaming is disabled by setting pfEnableThinning to FALSE, the reader will not request any bandwidth corrections.

This feature applies only to content streaming from a server running Windows Media Services.

This method is equivalent to specifying the WMThinning modifier in the URL. The modifier WMThinning=1 enables thinning, while WMThinning=0 disables it. For example:

mms://MyServer/MyVideo.wmv?WMThinning=1

Using the WMThinning URL modifier will override the setting specified with this method.

Requirements


Minimum supported client	Windows 2000 Professional [desktop apps only],Windows Media Format 9 Series 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)