C Specification

The VkVideoEncodeRateControlInfoKHR structure is defined as:

// Provided by VK_KHR_video_encode_queue
typedef struct VkVideoEncodeRateControlInfoKHR {
    VkStructureType                                sType;
    const void*                                    pNext;
    VkVideoEncodeRateControlFlagsKHR               flags;
    VkVideoEncodeRateControlModeFlagBitsKHR        rateControlMode;
    uint32_t                                       layerCount;
    const VkVideoEncodeRateControlLayerInfoKHR*    pLayers;
} VkVideoEncodeRateControlInfoKHR;

Members

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • flags is reserved for future use.

  • rateControlMode is a VkVideoEncodeRateControlModeFlagBitsKHR value specifying the encode stream rate control mode.

  • layerCount specifies the number of rate control layers in the video encode stream.

  • pLayers is a pointer to an array of VkVideoEncodeRateControlLayerInfoKHR structures specifying the rate control configurations of layerCount rate control layers.

Description

Including this structure in the pNext chain of VkVideoCodingControlInfoKHR and including VK_VIDEO_CODING_CONTROL_ENCODE_RATE_CONTROL_BIT_KHR in VkVideoCodingControlInfoKHR::flags will define stream rate control settings for video encoding.

Additional structures providing codec-specific rate control parameters may need to be included in the pNext chain of VkVideoCodingControlInfoKHR depending on the codec profile the bound video session was created with and the parameters specified in VkVideoEncodeRateControlInfoKHR (see Video Coding Control).

To ensure that the video session is properly initialized with stream-level rate control settings, the application must call vkCmdControlVideoCodingKHR with stream-level rate control settings at least once in execution order before the first vkCmdEncodeVideoKHR command that is executed after video session reset. If not provided, default implementation-specific stream rate control settings will be used.

Stream rate control settings can also be re-initialized during an active video encoding session. The re-initialization takes effect whenever the VkVideoEncodeRateControlInfoKHR structure is included in the pNext chain of the VkVideoCodingControlInfoKHR structure in the call to vkCmdControlVideoCodingKHR, and only impacts vkCmdEncodeVideoKHR operations that follow in execution order.

Valid Usage (Implicit)

  • VUID-VkVideoEncodeRateControlInfoKHR-sType-sType
    sType must be VK_STRUCTURE_TYPE_VIDEO_ENCODE_RATE_CONTROL_INFO_KHR

  • VUID-VkVideoEncodeRateControlInfoKHR-flags-zerobitmask
    flags must be 0

  • VUID-VkVideoEncodeRateControlInfoKHR-rateControlMode-parameter
    If rateControlMode is not 0, rateControlMode must be a valid VkVideoEncodeRateControlModeFlagBitsKHR value

  • VUID-VkVideoEncodeRateControlInfoKHR-pLayers-parameter
    If layerCount is not 0, pLayers must be a valid pointer to an array of layerCount valid VkVideoEncodeRateControlLayerInfoKHR structures

See Also

VK_KHR_video_encode_queue, VkStructureType, VkVideoEncodeRateControlFlagsKHR, VkVideoEncodeRateControlLayerInfoKHR, VkVideoEncodeRateControlModeFlagBitsKHR

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

Copyright 2014-2023 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0