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## Extension and Version Dependencies

• Requires support for Vulkan 1.0

## Extension Proposal

2022-05-02

IP Status

No known IP claims.

Contributors
• Jan-Harald Fredriksen, Arm

• Andrew Garrard, Imagination

• Lisa Wu, Arm

• Peter Kohaut, Arm

## Description

This extension enables fixed-rate image compression and adds the ability to control when this kind of compression can be applied. Many implementations support some form of framebuffer compression. This is typically transparent to applications as lossless compression schemes are used. With fixed-rate compression, the compression is done at a defined bitrate. Such compression algorithms generally produce results that are visually lossless, but the results are typically not bit-exact when compared to a non-compressed result. The implementation may not be able to use the requested compression rate in all cases. This extension adds a query that can be used to determine the compression scheme and rate that was applied to an image.

## New Enum Constants

• VK_EXT_IMAGE_COMPRESSION_CONTROL_EXTENSION_NAME

• VK_EXT_IMAGE_COMPRESSION_CONTROL_SPEC_VERSION

• Extending VkResult:

• VK_ERROR_COMPRESSION_EXHAUSTED_EXT

• Extending VkStructureType:

• VK_STRUCTURE_TYPE_IMAGE_COMPRESSION_CONTROL_EXT

• VK_STRUCTURE_TYPE_IMAGE_COMPRESSION_PROPERTIES_EXT

• VK_STRUCTURE_TYPE_IMAGE_SUBRESOURCE_2_EXT

• VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_IMAGE_COMPRESSION_CONTROL_FEATURES_EXT

• VK_STRUCTURE_TYPE_SUBRESOURCE_LAYOUT_2_EXT

## Version History

• Revision 1, 2022-05-02 (Jan-Harald Fredriksen)

• Initial draft