VkVideoEncodeH265RateControlLayerInfoKHR(3)

C Specification

The VkVideoEncodeH265RateControlLayerInfoKHR structure is defined as:

// Provided by VK_KHR_video_encode_h265
typedef struct VkVideoEncodeH265RateControlLayerInfoKHR {
    VkStructureType                  sType;
    const void*                      pNext;
    VkBool32                         useMinQp;
    VkVideoEncodeH265QpKHR           minQp;
    VkBool32                         useMaxQp;
    VkVideoEncodeH265QpKHR           maxQp;
    VkBool32                         useMaxFrameSize;
    VkVideoEncodeH265FrameSizeKHR    maxFrameSize;
} VkVideoEncodeH265RateControlLayerInfoKHR;

Members

sType is a VkStructureType value identifying this structure.
pNext is NULL or a pointer to a structure extending this structure.
useMinQp indicates whether the QP values determined by rate control will be clamped to the lower bounds on the QP values specified in minQp.
minQp specifies the lower bounds on the QP values, for each picture type, that the implementation’s rate control algorithm will use when useMinQp is set to VK_TRUE.
useMaxQp indicates whether the QP values determined by rate control will be clamped to the upper bounds on the QP values specified in maxQp.
maxQp specifies the upper bounds on the QP values, for each picture type, that the implementation’s rate control algorithm will use when useMaxQp 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 picture type.
maxFrameSize specifies the upper bounds on the encoded frame size, for each picture type, when useMaxFrameSize is set to VK_TRUE.

Description

When used, the values in minQp and maxQp guarantee that the effective QP values used by the implementation will respect those lower and upper bounds, respectively. However, limiting the range of QP 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 picture type, specified in the maxFrameSize member of VkVideoEncodeH265RateControlLayerInfoKHR.

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_H265_BIT_KHR, it specifies the H.265-specific rate control parameters of the rate control layer corresponding to that element of pLayers.

Valid Usage

VUID-VkVideoEncodeH265RateControlLayerInfoKHR-useMinQp-08297
If useMinQp is VK_TRUE, then the qpI, qpP, and qpB members of minQp must all be between VkVideoEncodeH265CapabilitiesKHR::minQp and VkVideoEncodeH265CapabilitiesKHR::maxQp, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the used video profile
VUID-VkVideoEncodeH265RateControlLayerInfoKHR-useMaxQp-08298
If useMaxQp is VK_TRUE, then the qpI, qpP, and qpB members of maxQp must all be between VkVideoEncodeH265CapabilitiesKHR::minQp and VkVideoEncodeH265CapabilitiesKHR::maxQp, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the used video profile
VUID-VkVideoEncodeH265RateControlLayerInfoKHR-useMinQp-08299
If useMinQp is VK_TRUE and VkVideoEncodeH265CapabilitiesKHR::flags, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the used video profile, does not include VK_VIDEO_ENCODE_H265_CAPABILITY_PER_PICTURE_TYPE_MIN_MAX_QP_BIT_KHR, then the qpI, qpP, and qpB members of minQp must all specify the same value
VUID-VkVideoEncodeH265RateControlLayerInfoKHR-useMaxQp-08300
If useMaxQp is VK_TRUE and VkVideoEncodeH265CapabilitiesKHR::flags, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the used video profile, does not include VK_VIDEO_ENCODE_H265_CAPABILITY_PER_PICTURE_TYPE_MIN_MAX_QP_BIT_KHR, then the qpI, qpP, and qpB members of maxQp must all specify the same value
VUID-VkVideoEncodeH265RateControlLayerInfoKHR-useMinQp-08375
If useMinQp and useMaxQp are both VK_TRUE, then the qpI, qpP, and qpB members of minQp must all be less than or equal to the respective members of maxQp

Valid Usage (Implicit)

VUID-VkVideoEncodeH265RateControlLayerInfoKHR-sType-sType
sType must be VK_STRUCTURE_TYPE_VIDEO_ENCODE_H265_RATE_CONTROL_LAYER_INFO_KHR
VUID-VkVideoEncodeH265RateControlLayerInfoKHR-minQp-parameter
minQp must be a valid VkVideoEncodeH265QpKHR structure
VUID-VkVideoEncodeH265RateControlLayerInfoKHR-maxQp-parameter
maxQp must be a valid VkVideoEncodeH265QpKHR structure
VUID-VkVideoEncodeH265RateControlLayerInfoKHR-maxFrameSize-parameter
maxFrameSize must be a valid VkVideoEncodeH265FrameSizeKHR structure

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.

Copyright

SPDX-License-Identifier: CC-BY-4.0

VkVideoEncodeH265RateControlLayerInfoKHR(3) Manual Page

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