AVDecMmcss property

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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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

Specifies the Multimedia Class Scheduler Service (MMCSS) class for the decoding thread.

This property is read/write.

Data type

BSTR (VT_BSTR)

Property GUID

CODECAPI_AVDecMmcssClass

Property value

The value of this property is the name of the MMCSS class.

Remarks

MMCSS enables applications to ensure that time-sensitive processing has prioritized access to CPU resources. It works by elevating registered threads to higher thread priorities while periodically decreasing their priorities to yield time to other processes.

The recommended value for audio decoders is "Audio," and the recommended value for video decoders is "Playback."

If the MMCSS service is not available or the specified MMCSS class does not exist, setting the property has no effect.

Requirements

Requirement Value
Header
Uuids.h

See also

Codec API Properties

ICodecAPI Interface