VkVideoFormatAV1QuantizationMapPropertiesKHR

When calling vkGetPhysicalDeviceVideoFormatPropertiesKHR, the VkVideoFormatAV1QuantizationMapPropertiesKHR structure can be included in the pNext chain of the VkVideoFormatPropertiesKHR structure to retrieve video format properties specific to video encode quantization maps used with an AV1 encode profile.

The VkVideoFormatAV1QuantizationMapPropertiesKHR structure is defined as:

typedef struct VkVideoFormatAV1QuantizationMapPropertiesKHR {
    VkStructureType sType;
    void* pNext;
    VkVideoEncodeAV1SuperblockSizeFlagsKHR compatibleSuperblockSizes;
} VkVideoFormatAV1QuantizationMapPropertiesKHR;

• sType is a VkStructureType value identifying this structure.
• pNext is NULL or a pointer to a structure extending this structure.
• compatibleSuperblockSizes is a bitmask of VkVideoEncodeAV1SuperblockSizeFlagBitsKHR indicating the AV1 superblock sizes that quantization maps using this video format are compatible with.

  The value of compatibleSuperblockSizes does not limit the use of the specific quantization map format, but does limit the implementation in being able to encode pictures with superblock sizes not included in compatibleSuperblockSizes but otherwise supported by the used video profile, as indicated by VkVideoEncodeAV1CapabilitiesKHR::superblockSizes. In particular, using smaller quantization map texel sizes may prevent implementations from encoding with larger superblock sizes which may have a negative impact on the efficiency of the encoder.

The values returned in this structure are only defined if the allowed image usage flags returned in VkVideoFormatPropertiesKHR::imageUsageFlags for this video format include VK_IMAGE_USAGE_VIDEO_ENCODE_QUANTIZATION_DELTA_MAP_BIT_KHR or VK_IMAGE_USAGE_VIDEO_ENCODE_EMPHASIS_MAP_BIT_KHR.