MF_QUALITY_DROP_MODE enumeration

Specifies how aggressively a pipeline component should drop samples.

Syntax

typedef enum _MF_QUALITY_DROP_MODE { 
  MF_DROP_MODE_NONE  = 0x0,
  MF_DROP_MODE_1     = 0x1,
  MF_DROP_MODE_2     = 0x2,
  MF_DROP_MODE_3     = 0x3,
  MF_DROP_MODE_4     = 0x4,
  MF_DROP_MODE_5     = 0x5,
  MF_NUM_DROP_MODES  = 0x6
} MF_QUALITY_DROP_MODE;

Constants

MF_DROP_MODE_NONE

Normal processing of samples. Drop mode is disabled.

MF_DROP_MODE_1

First drop mode (least aggressive).

MF_DROP_MODE_2

Second drop mode.

MF_DROP_MODE_3

Third drop mode.

MF_DROP_MODE_4

Fourth drop mode.

MF_DROP_MODE_5

Fifth drop mode (most aggressive, if it is supported; see Remarks).

MF_NUM_DROP_MODES

Maximum number of drop modes. This value is not a valid flag.

Remarks

In drop mode, a component drops samples, more or less aggressively depending on the level of the drop mode. The specific algorithm used depends on the component. Mode 1 is the least aggressive mode, and mode 5 is the most aggressive. A component is not required to implement all five levels.

For example, suppose an encoded video stream has three B-frames between each pair of P-frames. A decoder might implement the following drop modes:

• Mode 1: Drop one out of every three B frames.

• Mode 2: Drop one out of every two B frames.

• Mode 3: Drop all delta frames.

• Modes 4 and 5: Unsupported.

The enhanced video renderer (EVR) can drop video frames before sending them to the EVR mixer.

Requirements

See also

IMFQualityAdvise

Media Foundation Enumerations