Microsoft DirectX 9.0

IDMOQualityControl Interface

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.

In addition to the methods inherited from IUnknown, the IDMOQualityControl interface exposes the following methods.

Method Description
GetStatus Determines whether quality control is active.
SetNow Specifies the earliest time stamp for which the DMO should deliver data.
SetStatus Enables or disables quality control.


Declared in Mediaobj.h; include Dmo.h.

Link to Dmoguids.lib.