C Specification

The VkVideoEncodeAV1RateControlLayerInfoKHR structure is defined as:

// Provided by VK_KHR_video_encode_av1
typedef struct VkVideoEncodeAV1RateControlLayerInfoKHR {
    VkStructureType                 sType;
    const void*                     pNext;
    VkBool32                        useMinQIndex;
    VkVideoEncodeAV1QIndexKHR       minQIndex;
    VkBool32                        useMaxQIndex;
    VkVideoEncodeAV1QIndexKHR       maxQIndex;
    VkBool32                        useMaxFrameSize;
    VkVideoEncodeAV1FrameSizeKHR    maxFrameSize;
} VkVideoEncodeAV1RateControlLayerInfoKHR;

Members

  • 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.

Description

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.

Note

In general, applications need to configure rate control parameters appropriately in order to be able to get the desired rate control behavior, as described in the Video Encode Rate Control section.

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.

Valid Usage
  • VUID-VkVideoEncodeAV1RateControlLayerInfoKHR-useMinQIndex-10300
    If useMinQIndex is VK_TRUE, then the intraQIndex, predictiveQIndex, and bipredictiveQIndex members of minQIndex must all be between VkVideoEncodeAV1CapabilitiesKHR::minQIndex and VkVideoEncodeAV1CapabilitiesKHR::maxQIndex, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the used video profile

  • VUID-VkVideoEncodeAV1RateControlLayerInfoKHR-useMinQIndex-10301
    If useMinQIndex is VK_TRUE and VkVideoEncodeAV1CapabilitiesKHR::flags, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the used video profile, does not include VK_VIDEO_ENCODE_AV1_CAPABILITY_PER_RATE_CONTROL_GROUP_MIN_MAX_Q_INDEX_BIT_KHR, then the intraQIndex, predictiveQIndex, and bipredictiveQIndex members of minQIndex must all specify the same value

  • VUID-VkVideoEncodeAV1RateControlLayerInfoKHR-useMaxQIndex-10302
    If useMaxQIndex is VK_TRUE, then the intraQIndex, predictiveQIndex, and bipredictiveQIndex members of maxQIndex must all be between VkVideoEncodeAV1CapabilitiesKHR::minQIndex and VkVideoEncodeAV1CapabilitiesKHR::maxQIndex, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the used video profile

  • VUID-VkVideoEncodeAV1RateControlLayerInfoKHR-useMaxQIndex-10303
    If useMaxQIndex is VK_TRUE and VkVideoEncodeAV1CapabilitiesKHR::flags, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the used video profile, does not include VK_VIDEO_ENCODE_AV1_CAPABILITY_PER_RATE_CONTROL_GROUP_MIN_MAX_Q_INDEX_BIT_KHR, then the intraQIndex, predictiveQIndex, and bipredictiveQIndex members of maxQIndex must all specify the same value

  • VUID-VkVideoEncodeAV1RateControlLayerInfoKHR-useMinQIndex-10304
    If useMinQIndex and useMaxQIndex are both VK_TRUE, then the intraQIndex, predictiveQIndex, and bipredictiveQIndex members of minQIndex must all be less than or equal to the respective members of maxQIndex

Valid Usage (Implicit)
  • VUID-VkVideoEncodeAV1RateControlLayerInfoKHR-sType-sType
    sType must be VK_STRUCTURE_TYPE_VIDEO_ENCODE_AV1_RATE_CONTROL_LAYER_INFO_KHR

  • VUID-VkVideoEncodeAV1RateControlLayerInfoKHR-minQIndex-parameter
    minQIndex must be a valid VkVideoEncodeAV1QIndexKHR structure

  • VUID-VkVideoEncodeAV1RateControlLayerInfoKHR-maxQIndex-parameter
    maxQIndex must be a valid VkVideoEncodeAV1QIndexKHR structure

  • VUID-VkVideoEncodeAV1RateControlLayerInfoKHR-maxFrameSize-parameter
    maxFrameSize must be a valid VkVideoEncodeAV1FrameSizeKHR structure

See Also

Document Notes

For more information, see the Vulkan Specification

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

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SPDX-License-Identifier: CC-BY-4.0