Vulkan rgb format 5，这是因为 y、u、v 和 rgb 的取值范围不同。yuv 格式中的 y 分量的取值范围是 [0, 1]，u 和 v 分量的取值范围是 [-0. Because the mapping and color conversion is separated from the format, Vulkan uses “RGB” color channel notations in the formats, and the conversion then describes the I'm following vulkan-tutorial. VK_KHR_sampler_ycbcr_conversion and VK_EXT_ycbcr_2plane_444_formats add multi-planar formats to Vulkan. If i understand correctly, the VkFormat that corresponds to NV12 is VK_FORMAT_G8_B8R8_2PLANE_420_UNORM. The compressed texture formats used by Vulkan are described in the specifically identified sections of the Khronos Data Format Specification, version 1. RGB HDR format, with 9 bit mantissa per channel and a 5 bit shared exponent. Three partial-precision floating-point numbers encoded into a single 32-bit value all sharing the same 5-bit exponent (variant of s10e5, which is sign bit, 10-bit mantissa, and 5-bit biased(15) exponent). In planar formats, we see that 3 color components are spread out across 3 planes, with a “420” here to mean that the second and third components are half resolution. The Vulkan specification separately describes each multi-planar format representation and its mapping to each color component. My one question is that, why do I get correct colors when using VK_FORMAT_R8G8B8A8_SRGB as well? Jun 21, 2021 · I'd like to transfer and translate the image to a device VkImage in the usual VK_FORMAT_R8G8B8A8_UNORM format. With a _UNORM format the colors will be correct. Dec 1, 2019 · VK_KHR_sampler_ycbcr_conversion adds a lot of new texture formats to Vulkan. So, basically the color that is outputted from the fragment shader needs to match the surface format color format to get the correct values; otherwise, a value that is in UNORM will just be used as if it is SRGB, which won't output correct values. Your doubts are totally justified: The code in question arguably does not show a best practice approach. So if you choose UNORM, 0, what you’ll get is an image that Vulkan will render to without performing sRGB colorspace conversion. I have a NV12 YCbCr image which I want to render onto two triangles forming a quad. The native Vulkan format we can then use to create the Vulkan image from can be taken from the ktxTexture object: VkFormat format = (VkFormat)ktx_texture->vkFormat; // Create a buffer to store the transcoded ktx texture data for staging to the GPU VkBufferCreateInfo buffer_create_info = vkb::initializers::buffer_create_info(); buffer_create UNORM无符号归一化格式， unsigned normalized. Packed formats are for the purposes of address alignment. Vulkan 格式用于描述内存的布局方式。本章旨在简要概述 Vulkan 中各种各样的格式变体，以及如何使用它们。更详细的信息请阅读 Vulkan Spec格式章节和 Khronos 数据格式规范。 使用VkFormat最常见的场景是创建VkImage。 知乎，中文互联网高质量的问答社区和创作者聚集的原创内容平台，于 2011 年 1 月正式上线，以「让人们更好的分享知识、经验和见解，找到自己的解答」为品牌使命。知乎凭借认真、专业、友善的社区氛围、独特的产品机制以及结构化和易获得的优质内容，聚集了中文互联网科技、商业、影视 Apr 13, 2023 · The problem is that when you create an image with the format VK_FORMAT_R8G8B8A8_UINT, the UINT suffix is explicitly telling Vulkan that you want the RGBA values to each appear in the shader as an 8-bit unsigned integer. If the driver simply does not support RGB textures, then your best bet is almost certainly to use RGBA textures and just ignore the alpha channel or Jun 17, 2016 · In case of sRGB destination format, linear RGB values are converted to nonlinear representation before writing the pixel to the image. . Aug 2, 2020 · While the Vulkan image format defines how Vulkan will work with the image, the colorspace will define how the display system will work with it. For YUV420p, we’re going to look at this format, VK_FORMAT_G8_B8_R8_3PLANE_420_UNORM. Normally I'd do this by creating a host VkBuffer and then transfering the image to a VkImage with vkCmdCopyBufferToImage , but I need to swizzle the components around and apply that division as part of that process. 直接使用SRGB颜色有很大挑战，所以我们使用RGB作为颜色格式，这一格式可以通过VK_FORMAT_B8G8R8A8_UNORM宏指定。 Vulkan通过返回一个format成员变量值为VK_FORMAT_UNDEFINED的VkSurfaceFormatKHR表明表面没有自己的首选格式，这时，我们直接返回我们设定的格式： Aug 11, 2017 · The use of Y′C B C R sampler conversion is an area in 3D graphics not used by most Vulkan developers. Jan 12, 2023 · The answer to your question is: You generally do not prefer non-sRGB formats for the swapchain images. VK_FORMAT_BC1_RGB_SRGB_BLOCK specifies a three-component, block-compressed format where each 64-bit compressed texel block encodes a 4×4 rectangle of unsigned normalized RGB texel data with sRGB nonlinear encoding. Choosing a format for the view that is different from the resource format is not a trivial matter. VK_FORMAT_R8G8B8A8_UNORM // 4个成分，32位无符号归一化格式，8位R占在零个字节，8位G在第一个字节，8位B在第二个字节，8位A在第三个字节。SNORM 有符号归一化格式… VK_FORMAT_R8G8B8A8_UNORM 最常用到的rgba图像格式; VK_FORMAT_D24_UNORM_S8_UINT 有两个属性，每个像素点32位，包括一个24位的深度值和8位 模板值 。 VK_FORMAT_BC1_RGB_SRGB_BLOCK BC1压缩的SRGB图; mipLevels可以指定该纹理的 mipmap 级别，更大的miplevel会消耗更多内存，但是不超过原来纹理 Textures Output Format Conversion requires that all implementations implicitly apply the sRGB EOTF-1 on R, G, and B components when shaders write to an sRGB pixel format image, which is useful for sRGB color spaces. ” There are over 100 formats to Dec 19, 2018 · I've been trying to sample a YCbCr image in Vulkan but I keep getting incorrect results, and I was hoping someone might be able to spot my mistake. If I setup a swapchain image with _SRGB format and SRGB_NONLINEAR color space, the rendered colors will be wrong. This format has no alpha and is considered opaque. For the format, we match it with the stb format STBI_rgb_alpha. I will focus on explaining this process for DirectX 12 and Vulkan APIs. Apr 11, 2024 · Vulkan运行时能够直接加载和执行SPIR-V代码。在Vulkan中创建着色器模块，将SPIR-V代码加载到这些模块中。创建描述符集和描述符集布局，用于向着色器提供输入数据（如YUV纹理）和输出数据（如转换后的RGB图像）。_vulkan glsl 文章浏览阅读2. Nov 8, 2022 · The difficulty comes from the fact that both the resource and the view have formats, which can be different. Oct 21, 2018 · How to perform conversion from rgb images to the yuv420p format in the context of mpeg-4 encoding using Glsl and Vulkan. 7k次，点赞4次，收藏6次。目标在《图形API学习工程（11）：使用纹理》中：目标是：讨论为何要指定纹理格式导致格式不同的原因不同格式对应的位数常见关键字有些是公用的，有些仅在DXGI_FORMAT或VkFormat里出现。 The Vulkan spec explicitly mentions several RGB-only formats in the core spec, so if you're not able to upload and use RGB-only textures then that's the responsibility of a specific vendor/driver. What you actually want is VK_FORMAT_R8G8B8A8_UNORM instead. Apr 10, 2024 · 在 yuv 和 rgb 之间的转换公式中，u 和 v 分量都减去了 0. 3. The planes can be accessed separately with VK_IMAGE_ASPECT_PLANE_0_BIT, VK_IMAGE_ASPECT_PLANE_1_BIT, and VK_IMAGE_ASPECT_PLANE_2_BIT. mipmap generation only works properly in linear space), but this says you'll only get that behaviour if the formats are different. It is mainly used for processing inputs from video decoders and cameras. Nov 21, 2021 · When creating my swapchain, using vkCreateSwapchainKHR (actually I am using the C++ interface, but it seems that all communication is done using the C API) I pass a pointer to a VkSwapchainCreateInfoKHR that has a member imageFormat described by the specs as “imageFormat is a VkFormat value specifying the format the swapchain image(s) will be created with. My question are, Is this a common issue or is there any wrong with my understanding of baking texture? I would not like to introduce SRGB annotation to the renderpass, as far as I know, GPU will process SRGB<=>RGB conversion upon load and store. Unless otherwise described, the quantities encoded in these compressed formats are treated as normalized, unsigned values. 5, 0. Feb 27, 2021 · When I change my swapchain format from VK_FORMAT_B8G8R8A8_UNORM to VK_FORMAT_B8G8R8A8_SRGB I observe that the overall brightness of the frames is greatly increased, and also there are some minor color shifts. Practical guide to vulkan graphics programming. g. Converting RGBA to Yuv420p in Glsl/Vulkan This post is about doing an image conversion on the graphics card itself. We calculate image sizes by doing 4 bytes per pixel, and texWidth * texHeight number of pixels. com and I don't understand why when creating the swap chain, we choose a VkSurfaceFormatKHR with a format of VK_FORMAT_B8G8R8A8_SRGB instead of VK_FORMAT_R8G8B8A8_SRGB which is the common type and simpler to work with to my beginner eyes. Conversion to/from linear RGB is important for bilinear filtering (e. VK_FORMAT_BC3_SRGB_BLOCK specifies a four-component, block-compressed format where each 128-bit compressed texel block encodes a 4×4 rectangle of unsigned normalized RGBA texel data with the first 64 bits encoding alpha values followed by 64 bits encoding RGB values with sRGB nonlinear encoding. 5]。而 rgb 格式中，r、g、b 三个分量的取值范围都是 [0, 1]。 So I am confused about the behavior of Vulkan about this case. Because the mapping and color conversion is separated from the format, Vulkan uses “RGB” color channel notations in the formats, and the conversion then describes the mapping from these channels to the input to the color conversion. hkveo wyd bujp asvdww xveczyp eae bmjj uxbn fhfc ito ttjbcugw cmlr moambx artcgl nvqbpbk