IMFPMediaPlayer::GetSupportedRates method (mfplay.h)

项目
12/05/2018

[The feature associated with this page, MFPlay, is a legacy feature. It has been superseded by MediaPlayer and IMFMediaEngine. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer and IMFMediaEngine instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

Gets the range of supported playback rates.

Syntax

HRESULT GetSupportedRates(
  [in]  BOOL  fForwardDirection,
  [out] float *pflSlowestRate,
  [out] float *pflFastestRate
);

Parameters

[in] fForwardDirection

Specify TRUE to get the playback rates for forward playback. Specify FALSE to get the rates for reverse playback.

[out] pflSlowestRate

Receives the slowest supported rate.

[out] pflFastestRate

Receives the fastest supported rate.

Return value

This method can return one of these values.

Return code	Description
S_OK	The method succeeded.
MF_E_UNSUPPORTED_RATE	The current media item does not support playback in the requested direction (either forward or reverse).

Remarks

Playback rates are expressed as a ratio of the current rate to the normal rate. For example, 1.0 indicates normal playback speed, 0.5 indicates half speed, and 2.0 indicates twice speed. Positive values indicate forward playback, and negative values indicate reverse playback.

Requirements

Requirement	Value
Minimum supported client	Windows 7 [desktop apps only]
Minimum supported server	Windows Server 2008 R2 [desktop apps only]
Target Platform	Windows
Header	mfplay.h

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