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IDMOQualityControl interface (mediaobj.h)

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[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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.]

The IDMOQualityControl interface supports quality control on a Microsoft DirectX Media Object (DMO).

A DMO exposes this interface if it can respond to late samples. When quality control is enabled, the DMO attempts to process samples on time, discarding late samples if necessary. When quality control is disabled, the DMO processes every sample. By default, quality control is disabled.

Applications use this interface to enable or disable quality control. Using quality control is appropriate when you are viewing media data in real time. If you are capturing data to a file, do not enable quality control, because the DMO might discard samples. It does not matter in file capture whether samples arrive late, and you do not want to lose the data.

To use quality control, perform the following steps:

  1. Call the IDMOQualityControl::SetNow method with the reference time of the earliest sample to be processed.
  2. Call the IDMOQualityControl::SetStatus method with the DMO_QUALITY_STATUS_ENABLED flag.
To disable quality control, call SetStatus with no flag.

Inheritance

The IDMOQualityControl interface inherits from the IUnknown interface. IDMOQualityControl also has these types of members:

Methods

The IDMOQualityControl interface has these methods.

 
IDMOQualityControl::GetStatus

The GetStatus method determines whether quality control is active.
IDMOQualityControl::SetNow

The SetNow method specifies the earliest time stamp that the DMO will deliver.
IDMOQualityControl::SetStatus

The SetStatus method enables or disables quality control.

Requirements

Requirement Value
Target Platform Windows
Header mediaobj.h (include Dmoguids.lib)