MF_VIDEO_MAX_MB_PER_SEC attribute

Specifies, on IMFTransform, the maximum macroblock processing rate, in macroblocks per second, that is supported by the hardware encoder.

Data type

UINT32

Remarks

This is a read-only attribute.

This attribute is affected by the following properties:

• MF_MT_VIDEO_LEVEL (which is an alias of MF_MT_MPEG2_LEVEL)
• CODECAPI_AVEncCommonQualityVsSpeed
• CODECAPI_AVEncMPVDefaultBPictureCount

If the MF_MT_VIDEO_LEVEL attribute is present, the encoder should return the processing rate for the highest bitrate and resolution supported at the specified level. If the MF_MT_VIDEO_LEVEL attribute is not present then it should use a default level of 4.

If the CODECAPI_AVEncCommonQualityVsSpeed ICodecAPI property has been set, the encoder should return the processing rate corresponding to the value set for this property. If the CODECAPI_AVEncCommonQualityVsSpeed attribute is not present, then it should use a default value of 0 which should be the fastest processing mode.

If the CODECAPI_AVEncMPVDefaultBPictureCount ICodecAPI property has been set to a valid and supported value, the encoder should return the processing rate corresponding the value set for this property. If the CODECAPI_AVEncMPVDefaultBPictureCount attribute is not present, then it should use a default value of 0 B frames.

Only the lower 28 bits should be used by an application. The upper 4bits are reserved for future use. Applications should ignore the upper 4 bits and MFTs should set the upper 4 bits to 0.

H.265, VP8, VP9 and AV1 encoders: H.265, VP8, VP9 and AV1 codecs do not have the same definition of macroblock as H.264. These codecs can have smaller or larger coding blocks compared to H.264. For these encoders this attribute is defined as the number of 16x16 pixel blocks that can be processed per second.

This attribute is supported by the following encoders:

• H.264/AVC
• H.265/HEVC
• VP8, VP9
• AV1

Requirements

See also

Alphabetical List of Media Foundation Attributes