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D3D12DDI_VIDEO_ENCODER_RATE_CONTROL_QVBR1_0096 structure (d3d12umddi.h)

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The D3D12DDI_VIDEO_ENCODER_RATE_CONTROL_QVBR1_0096 structure contains the rate control definition for enhanced QVBR rate control mode.

Syntax

typedef struct D3D12DDI_VIDEO_ENCODER_RATE_CONTROL_QVBR1_0096 {
  UINT   InitialQP;
  UINT   MinQP;
  UINT   MaxQP;
  UINT64 MaxFrameBitSize;
  UINT64 TargetAvgBitRate;
  UINT64 PeakBitRate;
  UINT   ConstantQualityTarget;
  UINT64 VBVCapacity;
  UINT64 InitialVBVFullness;
  UINT   QualityVsSpeed;
} D3D12DDI_VIDEO_ENCODER_RATE_CONTROL_QVBR1_0096;

Members

InitialQP

When the D3D12DDI_VIDEO_ENCODER_RATE_CONTROL_FLAG_0080_ENABLE_INITIAL_QP flag is set, InitialQP can be used by the rate control algorithm.

MinQP

When the D3D12DDI_VIDEO_ENCODER_RATE_CONTROL_FLAG_0080_ENABLE_QP_RANGE flag is set, MinQP limits the quantization parameter (QP) range of the rate control algorithm.

MaxQP

When the D3D12DDI_VIDEO_ENCODER_RATE_CONTROL_FLAG_0080_ENABLE_QP_RANGE flag is set, MaxQP limits the QP range of the rate control algorithm.

MaxFrameBitSize

Maximum size for each frame to be encoded, in bits. When D3D12DDI_VIDEO_ENCODER_RATE_CONTROL_FLAG_0080_ENABLE_MAX_FRAME_SIZE is set, MaxFrameBitSize limits each frame's maximum size in the rate control algorithm.

TargetAvgBitRate

Average bitrate to be used, in bits per second.

PeakBitRate

Maximum bitrate that can be reached, in bits per second.

ConstantQualityTarget

Indicates the quality level. Values are codec-specific as each standard defines the range for this argument (for example, H.264 / HEVC 0-51, et cetera).

VBVCapacity

The Video Buffering Verifier (VBV) buffer capacity, in bits.

InitialVBVFullness

The initial fullness of the VBV buffer, in bits.

QualityVsSpeed

The quality versus speed trade-off. This value must be in the range [0, D3D12_FEATURE_DATA_VIDEO_ENCODER_SUPPORT1.MaxQualityVsSpeed]. The lower the value, the faster the encode operation.

The settings associated to each of the levels exposed by QualityVsSpeed must only refer to hardware/driver implementation optimizations and heuristics that aren't related to specific codec configurations or encoding tools selection, which are already independently exposed in the D3D12 API to the user individually. Please note that other codec configurations and codec encoding tools exposed through this API may also affect quality and speed.

Remarks

See D3D12 AV1 video encoding for more information.

Requirements

Requirement Value
Minimum supported client Windows 11, version 24H2 (WDDM 3.2)
Header d3d12umddi.h

See also

D3D12DDI_VIDEO_ENCODER_RATE_CONTROL_CONFIGURATION_PARAMS_0080_2

D3D12DDI_VIDEO_ENCODER_RATE_CONTROL_FLAGS_0080