vkGetPhysicalDeviceOpticalFlowImageFormatsNV(3)

# vkGetPhysicalDeviceOpticalFlowImageFormatsNV(3) Manual Page

## Name

vkGetPhysicalDeviceOpticalFlowImageFormatsNV - Query image formats for optical flow

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## C Specification

To enumerate the supported image formats for a specific optical flow usage, call:

    // Provided by VK_NV_optical_flow
    VkResult vkGetPhysicalDeviceOpticalFlowImageFormatsNV(
        VkPhysicalDevice                            physicalDevice,
        const VkOpticalFlowImageFormatInfoNV*       pOpticalFlowImageFormatInfo,
        uint32_t*                                   pFormatCount,
        VkOpticalFlowImageFormatPropertiesNV*       pImageFormatProperties);

## Parameters

- `physicalDevice` is the physical device being queried.

- `pOpticalFlowImageFormatInfo` is a pointer to a VkOpticalFlowImageFormatInfoNV structure specifying the optical flow usage for which information is returned.

- `pFormatCount` is a pointer to an integer related to the number of optical flow properties available or queried, as described below.

- `pImageFormatProperties` is a pointer to an array of VkOpticalFlowImageFormatPropertiesNV structures in which supported formats and image parameters are returned.

## Description

If `pImageFormatProperties` is `NULL`, then the number of optical flow properties supported for the given `physicalDevice` is returned in `pFormatCount`. Otherwise, `pFormatCount` must point to a variable set by the user to the number of elements in the `pImageFormatProperties` array, and on return the variable is overwritten with the number of values actually written to `pImageFormatProperties`. If the value of `pFormatCount` is less than the number of optical flow properties supported, at most `pFormatCount` values will be written to `pImageFormatProperties`, and `VK_INCOMPLETE` will be returned instead of `VK_SUCCESS`, to indicate that not all the available values were returned. Before creating an image to be used as a optical flow frame, obtain the supported image creation parameters by querying with vkGetPhysicalDeviceFormatProperties2 and vkGetPhysicalDeviceImageFormatProperties2 using one of the reported formats and adding VkOpticalFlowImageFormatInfoNV to the `pNext` chain of VkPhysicalDeviceImageFormatInfo2. When querying the parameters with vkGetPhysicalDeviceImageFormatProperties2 for images used for optical flow operations, the VkOpticalFlowImageFormatInfoNV::`usage` field should contain one or more of the bits defined in VkOpticalFlowUsageFlagBitsNV.

Valid Usage (Implicit)

- VUID-vkGetPhysicalDeviceOpticalFlowImageFormatsNV-physicalDevice-parameter
  `physicalDevice` must be a valid VkPhysicalDevice handle

- VUID-vkGetPhysicalDeviceOpticalFlowImageFormatsNV-pOpticalFlowImageFormatInfo-parameter
  `pOpticalFlowImageFormatInfo` must be a valid pointer to a valid VkOpticalFlowImageFormatInfoNV structure

- VUID-vkGetPhysicalDeviceOpticalFlowImageFormatsNV-pFormatCount-parameter
  `pFormatCount` must be a valid pointer to a `uint32_t` value

- VUID-vkGetPhysicalDeviceOpticalFlowImageFormatsNV-pImageFormatProperties-parameter
  If the value referenced by `pFormatCount` is not `0`, and `pImageFormatProperties` is not `NULL`, `pImageFormatProperties` must be a valid pointer to an array of `pFormatCount` VkOpticalFlowImageFormatPropertiesNV structures

Return Codes

On success, this command returns

  - `VK_SUCCESS`

  - `VK_INCOMPLETE`

On failure, this command returns

  - `VK_ERROR_EXTENSION_NOT_PRESENT`

  - `VK_ERROR_INITIALIZATION_FAILED`

  - `VK_ERROR_FORMAT_NOT_SUPPORTED`

| Note `VK_FORMAT_B8G8R8A8_UNORM`, `VK_FORMAT_R8_UNORM` and `VK_FORMAT_G8_B8R8_2PLANE_420_UNORM` are initially supported for images with optical usage `VK_OPTICAL_FLOW_USAGE_INPUT_BIT_NV`. `VK_FORMAT_R16G16_S10_5_NV` is initially supported for images with optical flow usage `VK_OPTICAL_FLOW_USAGE_OUTPUT_BIT_NV`, `VK_OPTICAL_FLOW_USAGE_HINT_BIT_NV` and `VK_OPTICAL_FLOW_USAGE_GLOBAL_FLOW_BIT_NV`. `VK_FORMAT_R8_UINT` and `VK_FORMAT_R32_UINT` are initially supported for images with optical flow usage `VK_OPTICAL_FLOW_USAGE_COST_BIT_NV`. It is recommended to use `VK_FORMAT_R8_UINT` because of the lower bandwidth.

## See Also

VK_NV_optical_flow, VkOpticalFlowImageFormatInfoNV, VkOpticalFlowImageFormatPropertiesNV, VkPhysicalDevice

## 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 2014-2022 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0