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IStreamBufferConfigure2::SetFFTransitionRates

  • Article
 
Microsoft DirectShow 9.0

IStreamBufferConfigure2::SetFFTransitionRates

This topic applies to Windows XP Service Pack 2 only.

The SetFFTransitionRates method sets the behavior of fast-forward play ("trick mode") in the Stream Buffer Engine.

Syntax

  HRESULT SetFFTransitionRates(
    DWORD 
  dwMaxFullFrameRate
  
    DWORD 
  dwMaxNonSkippingRate
  
);

Parameters

dwMaxFullFrameRate

[in]  Maximum playback rate for full-frame playback. The value must be greater than 1. The default value is 4.

dwMaxNonSkippingRate

[in]  Maximum playback rate for key-frame playback. The value must be greater than dwFullFrameRate. The default value is 6.

Return Values

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

Value Description
S_OK The method succeeded.

Remarks

At higher playback rates, the Stream Buffer Engine drops frames in order to maintain the desired rate. The following table shows how the values of dwMaxFullFrameRate and dwMaxNonSkippingRate affect playback.

Playback rate Behavior
rate <= dwMaxFullFrameRate Full-frame playback: All frames are sent.
dwMaxFullFrameRate < rate <= dwMaxNonSkippingRate Key-frame playback: All key frames are sent. Delta frames are skipped.
dwMaxNonSkippingRate < rate Key-frame playback with seeking: All delta frames are skipped, and some key frames are skipped. The number of skipped key frames is proportional to the rate.

The decoder may drop frames as well, depending on the data rate, the monitor refresh rate, and the CPU load.

Requirements

Header: Include Sbe.h.

See Also