C Specification

To enumerate the supported output, input and DPB image formats for a specific codec operation and video profile, call:

// Provided by VK_KHR_video_queue
VkResult vkGetPhysicalDeviceVideoFormatPropertiesKHR(
    VkPhysicalDevice                            physicalDevice,
    const VkPhysicalDeviceVideoFormatInfoKHR*   pVideoFormatInfo,
    uint32_t*                                   pVideoFormatPropertyCount,
    VkVideoFormatPropertiesKHR*                 pVideoFormatProperties);

Parameters

  • physicalDevice is the physical device being queried.

  • pVideoFormatInfo is a pointer to a VkPhysicalDeviceVideoFormatInfoKHR structure specifying the codec and video profile for which information is returned.

  • pVideoFormatPropertyCount is a pointer to an integer related to the number of video format properties available or queried, as described below.

  • pVideoFormatProperties is a pointer to an array of VkVideoFormatPropertiesKHR structures in which supported formats and image parameters are returned.

Description

If pVideoFormatProperties is NULL, then the number of video format properties supported for the given physicalDevice is returned in pVideoFormatPropertyCount. Otherwise, pVideoFormatPropertyCount must point to a variable set by the user to the number of elements in the pVideoFormatProperties array, and on return the variable is overwritten with the number of values actually written to pVideoFormatProperties. If the value of pVideoFormatPropertyCount is less than the number of video format properties supported, at most pVideoFormatPropertyCount values will be written to pVideoFormatProperties, and VK_INCOMPLETE will be returned instead of VK_SUCCESS, to indicate that not all the available values were returned.

If an implementation reports VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_COINCIDE_BIT_KHR is supported but VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_DISTINCT_BIT_KHR is not supported in VkVideoDecodeCapabilitiesKHR::flags, then to query for video format properties for decode DPB or output, VkPhysicalDeviceVideoFormatInfoKHR::imageUsage must have both VK_IMAGE_USAGE_VIDEO_DECODE_DPB_BIT_KHR and VK_IMAGE_USAGE_VIDEO_DECODE_DST_BIT_KHR set. Otherwise, the call will fail with VK_ERROR_IMAGE_USAGE_NOT_SUPPORTED_KHR.

If an implementation reports VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_DISTINCT_BIT_KHR is supported but VK_VIDEO_DECODE_CAPABILITY_DPB_AND_OUTPUT_COINCIDE_BIT_KHR is not supported in VkVideoDecodeCapabilitiesKHR::flags, then to query for video format properties for decode DPB, VkPhysicalDeviceVideoFormatInfoKHR::imageUsage must have VK_IMAGE_USAGE_VIDEO_DECODE_DPB_BIT_KHR set and VK_IMAGE_USAGE_VIDEO_DECODE_DST_BIT_KHR not set. Otherwise, the call will fail with VK_ERROR_IMAGE_USAGE_NOT_SUPPORTED_KHR. Similarly, to query for video format properties for decode output, VkPhysicalDeviceVideoFormatInfoKHR::imageUsage must have VK_IMAGE_USAGE_VIDEO_DECODE_DST_BIT_KHR set and VK_IMAGE_USAGE_VIDEO_DECODE_DPB_BIT_KHR not set. Otherwise, the call will fail with VK_ERROR_IMAGE_USAGE_NOT_SUPPORTED_KHR.

The imageUsage member of the VkPhysicalDeviceVideoFormatInfoKHR structure specifies the expected video usage flags that the returned video formats must support. Correspondingly, the imageUsageFlags member of each VkVideoFormatPropertiesKHR structure returned will contain at least the same set of image usage flags.

If the implementation supports using video input, output, or DPB images of a particular format in operations other than video decode/encode then the imageUsageFlags member of the corresponding VkVideoFormatPropertiesKHR structure returned will include additional image usage flags indicating that.

Note:

For most use cases, only decode or encode related usage flags are going to be specified. For a use case such as transcode, if the image were to be shared between decode and encode session(s), then both decode and encode related usage flags can be set.

Video format properties are always queried with respect to a specific set of video profiles, as defined by the VkVideoProfileKHR structure. These are specified by chaining the VkVideoProfilesKHR structure to pVideoFormatInfo.

For most use cases, the images are used by a single video session and a single video profile is provided. For a use case such as transcode, where a decode session output image can be used as encode input in one or more encode sessions, multiple video profiles corresponding to the video sessions that will share the image must be provided.

If any of the profiles specified via VkVideoProfilesKHR::pProfiles are not supported, then vkGetPhysicalDeviceVideoFormatPropertiesKHR returns one of the video-profile-specific error codes. Furthermore, if VkPhysicalDeviceVideoFormatInfoKHR::imageUsage includes any image usage flags not supported by the specified video profiles then vkGetPhysicalDeviceVideoFormatPropertiesKHR returns VK_ERROR_IMAGE_USAGE_NOT_SUPPORTED_KHR.

Multiple VkVideoFormatPropertiesKHR entries may be returned with the same format member with different componentMapping, imageType, or imageTiling values, as described later.

In addition, a different set of VkVideoFormatPropertiesKHR entries may be returned depending on the imageUsage member of the VkPhysicalDeviceVideoFormatInfoKHR structure, even for the same set of video profiles, for example, based on whether encode input, encode DPB, decode output, and/or decode DPB usage is requested.

The application can select the parameters returned in the VkVideoFormatPropertiesKHR entries and use compatible parameters when creating the input, output, and DPB images. The implementation will report all image creation and usage flags that are valid for images used with the requested video profiles but applications should create images only with those that are necessary for the particular use case.

Before creating an image, the application can obtain the complete set of supported image format features by calling vkGetPhysicalDeviceImageFormatProperties2 using parameters derived from the members of one of the reported VkVideoFormatPropertiesKHR entries and adding the same VkVideoProfilesKHR structure to the pNext chain of VkPhysicalDeviceImageFormatInfo2.

The componentMapping member of VkVideoFormatPropertiesKHR defines the ordering of the Y′CBCR color channels from the perspective of the video codec operations specified in VkVideoProfilesKHR. For example, if the implementation produces video decode output with the format VK_FORMAT_G8_B8R8_2PLANE_420_UNORM where the blue and red chrominance channels are swapped then the componentMapping member of the corresponding VkVideoFormatPropertiesKHR structure will have the following member values:

components.r = VK_COMPONENT_SWIZZLE_B;        // Cb component
components.g = VK_COMPONENT_SWIZZLE_IDENTITY; // Y component
components.b = VK_COMPONENT_SWIZZLE_R;        // Cr component
components.a = VK_COMPONENT_SWIZZLE_IDENTITY; // unused, defaults to 1.0
Valid Usage

  • [[VUID-{refpage}-pNext-06812]] VUID-{refpage}-pNext-06812
    The pNext chain of pVideoFormatInfo must include a valid VkVideoProfilesKHR structure with profileCount greater than 0

Valid Usage (Implicit)

  • VUID-vkGetPhysicalDeviceVideoFormatPropertiesKHR-physicalDevice-parameter
    physicalDevice must be a valid VkPhysicalDevice handle

  • VUID-vkGetPhysicalDeviceVideoFormatPropertiesKHR-pVideoFormatInfo-parameter
    pVideoFormatInfo must be a valid pointer to a valid VkPhysicalDeviceVideoFormatInfoKHR structure

  • VUID-vkGetPhysicalDeviceVideoFormatPropertiesKHR-pVideoFormatPropertyCount-parameter
    pVideoFormatPropertyCount must be a valid pointer to a uint32_t value

  • VUID-vkGetPhysicalDeviceVideoFormatPropertiesKHR-pVideoFormatProperties-parameter
    If the value referenced by pVideoFormatPropertyCount is not 0, and pVideoFormatProperties is not NULL, pVideoFormatProperties must be a valid pointer to an array of pVideoFormatPropertyCount VkVideoFormatPropertiesKHR structures

Return Codes
On success, this command returns

  • VK_SUCCESS

  • VK_INCOMPLETE

On failure, this command returns

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

  • VK_ERROR_IMAGE_USAGE_NOT_SUPPORTED_KHR

  • VK_ERROR_VIDEO_PROFILE_OPERATION_NOT_SUPPORTED_KHR

  • VK_ERROR_VIDEO_PROFILE_FORMAT_NOT_SUPPORTED_KHR

  • VK_ERROR_VIDEO_PICTURE_LAYOUT_NOT_SUPPORTED_KHR

  • VK_ERROR_VIDEO_PROFILE_CODEC_NOT_SUPPORTED_KHR

See Also

VK_KHR_video_queue, VkPhysicalDevice, VkPhysicalDeviceVideoFormatInfoKHR, VkVideoFormatPropertiesKHR

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