IMFPMediaPlayer::SetVolume 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 It has been superseded by MediaPlayer and IMFMediaEngine.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.]

Sets the audio volume.

Syntax

HRESULT SetVolume(
  [in] float flVolume
);

Parameters

[in] flVolume

The volume level. Volume is expressed as an attenuation level, where 0.0 indicates silence and 1.0 indicates full volume (no attenuation).

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.
MF_E_OUT_OF_RANGE	The flVolume parameter is invalid.

Remarks

If you call this method before playback starts, the setting is applied after playback starts.

This method does not change the master volume level for the player's audio session. Instead, it adjusts the per-channel volume levels for audio stream(s) that belong to the current media item. Other streams in the audio session are not affected. For more information, see Managing the Audio Session.

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

通过