C Specification
To obtain format properties of an Android hardware buffer, include a
VkAndroidHardwareBufferFormatPropertiesANDROID structure in the
pNext chain of the VkAndroidHardwareBufferPropertiesANDROID
structure passed to vkGetAndroidHardwareBufferPropertiesANDROID.
This structure is defined as:
typedef struct VkAndroidHardwareBufferFormatPropertiesANDROID {
VkStructureType sType;
void* pNext;
VkFormat format;
uint64_t externalFormat;
VkFormatFeatureFlags formatFeatures;
VkComponentMapping samplerYcbcrConversionComponents;
VkSamplerYcbcrModelConversion suggestedYcbcrModel;
VkSamplerYcbcrRange suggestedYcbcrRange;
VkChromaLocation suggestedXChromaOffset;
VkChromaLocation suggestedYChromaOffset;
} VkAndroidHardwareBufferFormatPropertiesANDROID;
Members
-
sTypeis the type of this structure. -
pNextisNULLor a pointer to an extension-specific structure. -
formatis the Vulkan format corresponding to the Android hardware buffer’s format, orVK_FORMAT_UNDEFINEDif there is not an equivalent Vulkan format. -
externalFormatis an implementation-defined external format identifier for use with VkExternalFormatANDROID. It must not be zero. -
formatFeaturesdescribes the capabilities of this external format when used with an image bound to memory imported frombuffer. -
samplerYcbcrConversionComponentsis the component swizzle that should be used in VkSamplerYcbcrConversionCreateInfo. -
suggestedYcbcrModelis a suggested color model to use in the VkSamplerYcbcrConversionCreateInfo. -
suggestedYcbcrRangeis a suggested numerical value range to use in VkSamplerYcbcrConversionCreateInfo. -
suggestedXChromaOffsetis a suggested X chroma offset to use in VkSamplerYcbcrConversionCreateInfo. -
suggestedYChromaOffsetis a suggested Y chroma offset to use in VkSamplerYcbcrConversionCreateInfo.
Description
If the Android hardware buffer has one of the formats listed in the
Format Equivalence
table, then format must have the equivalent Vulkan format listed in
the table.
Otherwise, format may be VK_FORMAT_UNDEFINED, indicating the
Android hardware buffer can only be used with an external format.
The formatFeatures member must include
VK_FORMAT_FEATURE_SAMPLED_IMAGE_BIT and at least one of
VK_FORMAT_FEATURE_MIDPOINT_CHROMA_SAMPLES_BIT or
VK_FORMAT_FEATURE_COSITED_CHROMA_SAMPLES_BIT, and should include
VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT and
VK_FORMAT_FEATURE_SAMPLED_IMAGE_YCBCR_CONVERSION_LINEAR_FILTER_BIT.
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Note
The |
Android hardware buffers with the same external format must have the same
support for VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT,
VK_FORMAT_FEATURE_MIDPOINT_CHROMA_SAMPLES_BIT,
VK_FORMAT_FEATURE_COSITED_CHROMA_SAMPLES_BIT,
VK_FORMAT_FEATURE_SAMPLED_IMAGE_YCBCR_CONVERSION_LINEAR_FILTER_BIT,
VK_FORMAT_FEATURE_SAMPLED_IMAGE_YCBCR_CONVERSION_SEPARATE_RECONSTRUCTION_FILTER_BIT,
and
VK_FORMAT_FEATURE_SAMPLED_IMAGE_YCBCR_CONVERSION_CHROMA_RECONSTRUCTION_EXPLICIT_FORCEABLE_BIT.
in formatFeatures.
Other format features may differ between Android hardware buffers that have
the same external format.
This allows applications to use the same VkSamplerYcbcrConversion
object (and samplers and pipelines created from them) for any Android
hardware buffers that have the same external format.
If format is not VK_FORMAT_UNDEFINED, then the value of
samplerYcbcrConversionComponents must be valid when used as the
components member of VkSamplerYcbcrConversionCreateInfo with
that format.
If format is VK_FORMAT_UNDEFINED, all members of
samplerYcbcrConversionComponents must be
VK_COMPONENT_SWIZZLE_IDENTITY.
Implementations may not always be able to determine the color model,
numerical range, or chroma offsets of the image contents, so the values in
VkAndroidHardwareBufferFormatPropertiesANDROID are only suggestions.
Applications should treat these values as sensible defaults to use in the
absence of more reliable information obtained through some other means.
If the underlying physical device is also usable via OpenGL ES with the
GL_OES_EGL_image_external
extension, the implementation should suggest values that will produce
similar sampled values as would be obtained by sampling the same external
image via samplerExternalOES in OpenGL ES using equivalent sampler
parameters.
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Note
Since
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See Also
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 (c) 2014-2020 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.