VkVideoEncodeAV1RateControlLayerInfoKHR

The VkVideoEncodeAV1RateControlLayerInfoKHR structure is defined as:

typedef struct VkVideoEncodeAV1RateControlLayerInfoKHR {
    VkStructureType sType;
    const void* pNext;
    VkBool32 useMinQIndex;
    VkVideoEncodeAV1QIndexKHR minQIndex;
    VkBool32 useMaxQIndex;
    VkVideoEncodeAV1QIndexKHR maxQIndex;
    VkBool32 useMaxFrameSize;
    VkVideoEncodeAV1FrameSizeKHR maxFrameSize;
} VkVideoEncodeAV1RateControlLayerInfoKHR;

• sType is a VkStructureType value identifying this structure.
• pNext is NULL or a pointer to a structure extending this structure.
• useMinQIndex indicates whether the quantizer index values determined by rate control will be clamped to the lower bounds on the quantizer index values specified in minQIndex.
• minQIndex specifies the lower bounds on the quantizer index values, for each rate control group, that the implementation’s rate control algorithm will use when useMinQIndex is set to VK_TRUE.
• useMaxQIndex indicates whether the quantizer index values determined by rate control will be clamped to the upper bounds on the quantizer index values specified in maxQIndex.
• maxQIndex specifies the upper bounds on the quantizer index values, for each rate control group, that the implementation’s rate control algorithm will use when useMaxQIndex is set to VK_TRUE.
• useMaxFrameSize indicates whether the implementation’s rate control algorithm should use the values specified in maxFrameSize as the upper bounds on the encoded frame size for each rate control group.
• maxFrameSize specifies the upper bounds on the encoded frame size, for each rate control group, when useMaxFrameSize is set to VK_TRUE.

When used, the values in minQIndex and maxQIndex guarantee that the effective quantizer index values used by the implementation will respect those lower and upper bounds, respectively. However, limiting the range of quantizer index values that the implementation is able to use will also limit the capabilities of the implementation’s rate control algorithm to comply to other constraints. In particular, the implementation may not be able to comply to the following:

• The average and/or peak bitrate values to be used for the encoded bitstream specified in the averageBitrate and maxBitrate members of the VkVideoEncodeRateControlLayerInfoKHR structure.
• The upper bounds on the encoded frame size, for each rate control group, specified in the maxFrameSize member of VkVideoEncodeAV1RateControlLayerInfoKHR.

When an instance of this structure is included in the pNext chain of a VkVideoEncodeRateControlLayerInfoKHR structure specified in one of the elements of the pLayers array member of the VkVideoEncodeRateControlInfoKHR structure passed to the vkCmdControlVideoCodingKHR command, VkVideoCodingControlInfoKHR::flags includes VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_BIT_KHR, and the bound video session was created with the video codec operation VK_VIDEO_CODEC_OPERATION_ENCODE_AV1_BIT_KHR, it specifies the AV1-specific rate control parameters of the rate control layer corresponding to that element of pLayers.