VkVideoEncodeH265RateControlInfoKHR

The VkVideoEncodeH265RateControlInfoKHR structure is defined as:

typedef struct VkVideoEncodeH265RateControlInfoKHR {
    VkStructureType sType;
    const void* pNext;
    VkVideoEncodeH265RateControlFlagsKHR flags;
    uint32_t gopFrameCount;
    uint32_t idrPeriod;
    uint32_t consecutiveBFrameCount;
    uint32_t subLayerCount;
} VkVideoEncodeH265RateControlInfoKHR;

• sType is a VkStructureType value identifying this structure.
• pNext is NULL or a pointer to a structure extending this structure.
• flags is a bitmask of VkVideoEncodeH265RateControlFlagBitsKHR specifying H.265 rate control flags.
• gopFrameCount is the number of frames within a group of pictures (GOP) intended to be used by the application. If it is 0, the rate control algorithm may assume an implementation-dependent GOP length. If it is UINT32_MAX, the GOP length is treated as infinite.
• idrPeriod is the interval, in terms of number of frames, between two IDR frames (see IDR period). If it is 0, the rate control algorithm may assume an implementation-dependent IDR period. If it is UINT32_MAX, the IDR period is treated as infinite.
• consecutiveBFrameCount is the number of consecutive B frames between I and/or P frames within the GOP.
• subLayerCount specifies the number of H.265 sub-layers that the application intends to use.

When an instance of this structure is included in the pNext chain of the VkVideoCodingControlInfoKHR structure passed to the vkCmdControlVideoCodingKHR command, and VkVideoCodingControlInfoKHR::flags includes VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_BIT_KHR, the parameters in this structure are used as guidance for the implementation’s rate control algorithm (see Video Coding Control).

If flags includes VK_VIDEO_ENCODE_H265_RATE_CONTROL_ATTEMPT_HRD_COMPLIANCE_BIT_KHR, then the rate control state is reset to an initial state to meet HRD compliance requirements. Otherwise the new rate control state may be applied without a reset depending on the implementation and the specified rate control parameters.