AVEncCommonBufferSize 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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 size of the buffer used during encoding. This property applies only to constant bit rate (CBR) and variable bit rate (VBR) encoding modes.

This property is read/write.

Data type

UINT32 (VT_UI4)

Property GUID

CODECAPI_AVEncCommonBufferSize

Property value

This property has a linear range of values. To get the supported range, call ICodecAPI::GetParameterRange. Parameter ranges are not supported for H.264 UVC 1.5 camera encoders.

Remarks

For some video formats the buffer size is specified in bits and for others it is specified in bytes. See the remarks below for specific information.

For MPEG video, this property defines the video buffer verifier (VBV) buffer size. The size of the buffer is in bits.

For H.264 video and Windows Media Video, the property defines the hypothetical reference decoder (HRD) size. The size of the buffer is in bytes.

For UVC 1.5 H264 encoding cameras, the CPB value sent to the camera encoder must be 16-bit aligned. The size of the buffer is in bytes.

This property is also used with H.264 UVC 1.5 camera encoders.

Requirements

See also

Codec API Properties

ICodecAPI Interface