我一直在尝试在Vulkan中采样YCbCr图像超过16个小时，但是我一直得到不正确的结果，我希望有人能够发现我的错误。
我有一个NV12 YCbCr图像，我想将该图像渲染到形成一个四边形的两个三角形上。如果我正确理解，则与NV12对应的VkFormat为VK_FORMAT_G8_B8R8_2PLANE_420_UNORM。以下是我希望可以使用的代码，但我将尝试解释我也想做的事情：
1）在pNext中创建具有VkSamplerYcbcrConversion（格式正确）的VkSampler
2）将NV12数据读取到登台缓冲区
3）以正确的格式创建VkImage并指定平面不相交
4）获取每个平面（0和1）的内存要求（以及平面1的偏移量）
5）为图像数据分配设备本地存储器
6）将每个平面绑定到内存中的正确位置
7）将登台缓冲区复制到图像存储器
8）创建与VkImage格式相同的VkImageView，并与pNext中的VkSampler创建相同的VkSamplerYcbcrConversionInfo。
VkSamplerYcbcrConversion ycbcr_sampler_conversion;
VkSamplerYcbcrConversionInfo ycbcr_info;
VkSampler ycbcr_sampler;
VkImage image;
VkDeviceMemory image_memory;
VkDeviceSize memory_offset_plane0, memory_offset_plane1;
VkImageView image_view;
enum YCbCrStorageFormat
{
NV12
};
unsigned char* ReadYCbCrFile(const std::string& filename, YCbCrStorageFormat storage_format, VkFormat vulkan_format, uint32_t* buffer_size, uint32_t* buffer_offset_plane1, uint32_t* buffer_offset_plane2)
{
std::ifstream file;
file.open(filename.c_str(), std::ios::in | std::ios::binary | std::ios::ate);
if (!file.is_open()) { ELOG("Failed to open YCbCr image"); }
*buffer_size = file.tellg();
file.seekg(0);
unsigned char* data;
switch (storage_format)
{
case NV12:
{
if (vulkan_format != VK_FORMAT_G8_B8R8_2PLANE_420_UNORM)
{
ILOG("A 1:1 relationship doesn't exist between NV12 and 420, exiting");
exit(1);
}
*buffer_offset_plane1 = (*buffer_size / 3) * 2;
*buffer_offset_plane2 = 0; //Not used
data = new unsigned char[*buffer_size];
file.read((char*)(data), *buffer_size);
break;
}
default:
ELOG("A YCbCr storage format is required");
break;
}
file.close();
return data;
}
VkFormatProperties format_properties;
vkGetPhysicalDeviceFormatProperties(physical_device, VK_FORMAT_G8_B8R8_2PLANE_420_UNORM, &format_properties);
bool cosited = false, midpoint = false;
if (format_properties.optimalTilingFeatures & VK_FORMAT_FEATURE_COSITED_CHROMA_SAMPLES_BIT)
{
cosited = true;
}
else if (format_properties.optimalTilingFeatures & VK_FORMAT_FEATURE_MIDPOINT_CHROMA_SAMPLES_BIT)
{
midpoint = true;
}
if (!cosited && !midpoint)
{
ELOG("Nither VK_FORMAT_FEATURE_COSITED_CHROMA_SAMPLES_BIT nor VK_FORMAT_FEATURE_MIDPOINT_CHROMA_SAMPLES_BIT is supported for VK_FORMAT_G8_B8R8_2PLANE_420_UNORM");
}
VkSamplerYcbcrConversionCreateInfo conversion_info = {};
conversion_info.sType = VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_CREATE_INFO;
conversion_info.pNext = NULL;
conversion_info.format = VK_FORMAT_G8_B8R8_2PLANE_420_UNORM;
conversion_info.ycbcrModel = VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709;
conversion_info.ycbcrRange = VK_SAMPLER_YCBCR_RANGE_ITU_FULL;
conversion_info.components.r = VK_COMPONENT_SWIZZLE_IDENTITY;
conversion_info.components.g = VK_COMPONENT_SWIZZLE_IDENTITY;
conversion_info.components.b = VK_COMPONENT_SWIZZLE_IDENTITY;
conversion_info.components.a = VK_COMPONENT_SWIZZLE_IDENTITY;
if (cosited)
{
conversion_info.xChromaOffset = VK_CHROMA_LOCATION_COSITED_EVEN;
conversion_info.yChromaOffset = VK_CHROMA_LOCATION_COSITED_EVEN;
}
else
{
conversion_info.xChromaOffset = VK_CHROMA_LOCATION_MIDPOINT;
conversion_info.yChromaOffset = VK_CHROMA_LOCATION_MIDPOINT;
}
conversion_info.chromaFilter = VK_FILTER_LINEAR;
conversion_info.forceExplicitReconstruction = VK_FALSE;
VkResult res = vkCreateSamplerYcbcrConversion(logical_device, &conversion_info, NULL, &ycbcr_sampler_conversion);
CHECK_VK_RESULT(res, "Failed to create YCbCr conversion sampler");
ILOG("Successfully created YCbCr conversion");
ycbcr_info.sType = VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_INFO;
ycbcr_info.pNext = NULL;
ycbcr_info.conversion = ycbcr_sampler_conversion;
VkSamplerCreateInfo sampler_info = {};
sampler_info.sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO;
sampler_info.pNext = &ycbcr_info;
sampler_info.flags = 0;
sampler_info.magFilter = VK_FILTER_LINEAR;
sampler_info.minFilter = VK_FILTER_LINEAR;
sampler_info.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
sampler_info.addressModeU = VK_SAMPLER_ADDRESS_MODE_REPEAT;
sampler_info.addressModeV = VK_SAMPLER_ADDRESS_MODE_REPEAT;
sampler_info.addressModeW = VK_SAMPLER_ADDRESS_MODE_REPEAT;
sampler_info.mipLodBias = 0.0f;
sampler_info.anisotropyEnable = VK_FALSE;
//sampler_info.maxAnisotropy IGNORED
sampler_info.compareEnable = VK_FALSE;
//sampler_info.compareOp = IGNORED
sampler_info.minLod = 0.0f;
sampler_info.maxLod = 1.0f;
sampler_info.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_BLACK;
sampler_info.unnormalizedCoordinates = VK_FALSE;
res = vkCreateSampler(logical_device, &sampler_info, NULL, &ycbcr_sampler);
CHECK_VK_RESULT(res, "Failed to create YUV sampler");
ILOG("Successfully created sampler with YCbCr in pNext");
std::string filename = "tree_nv12_1920x1080.yuv";
uint32_t width = 1920, height = 1080;
VkFormat format = VK_FORMAT_G8_B8R8_2PLANE_420_UNORM;
uint32_t buffer_size, buffer_offset_plane1, buffer_offset_plane2;
unsigned char* ycbcr_data = ReadYCbCrFile(filename, NV12, VK_FORMAT_G8_B8R8_2PLANE_420_UNORM, &buffer_size, &buffer_offset_plane1, &buffer_offset_plane2);
//Load image into staging buffer
VkDeviceMemory stage_buffer_memory;
VkBuffer stage_buffer = create_vk_buffer(buffer_size, VK_BUFFER_USAGE_TRANSFER_SRC_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, stage_buffer_memory);
void* stage_memory_ptr;
vkMapMemory(logical_device, stage_buffer_memory, 0, buffer_size, 0, &stage_memory_ptr);
memcpy(stage_memory_ptr, ycbcr_data, buffer_size);
vkUnmapMemory(logical_device, stage_buffer_memory);
delete[] ycbcr_data;
//Create image
VkImageCreateInfo img_info = {};
img_info.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
img_info.flags = VK_IMAGE_CREATE_DISJOINT_BIT;
img_info.imageType = VK_IMAGE_TYPE_2D;
img_info.extent.width = width;
img_info.extent.height = height;
img_info.extent.depth = 1;
img_info.mipLevels = 1;
img_info.arrayLayers = 1;
img_info.format = format;
img_info.tiling = VK_IMAGE_TILING_LINEAR;//VK_IMAGE_TILING_OPTIMAL;
img_info.initialLayout = VK_IMAGE_LAYOUT_PREINITIALIZED;
img_info.usage = VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_IMAGE_USAGE_SAMPLED_BIT;
img_info.samples = VK_SAMPLE_COUNT_1_BIT;
img_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
VkResult result = vkCreateImage(logical_device, &img_info, NULL, &image);
CHECK_VK_RESULT(result, "vkCreateImage failed to create image handle");
ILOG("Image created!");
//Get memory requirements for each plane and combine
//Plane 0
VkImagePlaneMemoryRequirementsInfo image_plane_info = {};
image_plane_info.sType = VK_STRUCTURE_TYPE_IMAGE_PLANE_MEMORY_REQUIREMENTS_INFO;
image_plane_info.pNext = NULL;
image_plane_info.planeAspect = VK_IMAGE_ASPECT_PLANE_0_BIT;
VkImageMemoryRequirementsInfo2 image_info2 = {};
image_info2.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_REQUIREMENTS_INFO_2;
image_info2.pNext = &image_plane_info;
image_info2.image = image;
VkImagePlaneMemoryRequirementsInfo memory_plane_requirements = {};
memory_plane_requirements.sType = VK_STRUCTURE_TYPE_IMAGE_PLANE_MEMORY_REQUIREMENTS_INFO;
memory_plane_requirements.pNext = NULL;
memory_plane_requirements.planeAspect = VK_IMAGE_ASPECT_PLANE_0_BIT;
VkMemoryRequirements2 memory_requirements2 = {};
memory_requirements2.sType = VK_STRUCTURE_TYPE_MEMORY_REQUIREMENTS_2;
memory_requirements2.pNext = &memory_plane_requirements;
vkGetImageMemoryRequirements2(logical_device, &image_info2, &memory_requirements2);
VkDeviceSize image_size = memory_requirements2.memoryRequirements.size;
uint32_t image_bits = memory_requirements2.memoryRequirements.memoryTypeBits;
//Set offsets
memory_offset_plane0 = 0;
memory_offset_plane1 = image_size;
//Plane 1
image_plane_info.planeAspect = VK_IMAGE_ASPECT_PLANE_1_BIT;
memory_plane_requirements.planeAspect = VK_IMAGE_ASPECT_PLANE_1_BIT;
vkGetImageMemoryRequirements2(logical_device, &image_info2, &memory_requirements2);
image_size += memory_requirements2.memoryRequirements.size;
image_bits = image_bits | memory_requirements2.memoryRequirements.memoryTypeBits;
//Allocate image memory
VkMemoryAllocateInfo allocate_info = {};
allocate_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
allocate_info.allocationSize = image_size;
allocate_info.memoryTypeIndex = get_device_memory_type(image_bits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
result = vkAllocateMemory(logical_device, &allocate_info, NULL, &image_memory);
CHECK_VK_RESULT(result, "vkAllocateMemory failed to allocate image memory");
//Bind each image plane to memory
std::vector<VkBindImageMemoryInfo> bind_image_memory_infos(2);
//Plane 0
VkBindImagePlaneMemoryInfo bind_image_plane0_info = {};
bind_image_plane0_info.sType = VK_STRUCTURE_TYPE_BIND_IMAGE_PLANE_MEMORY_INFO;
bind_image_plane0_info.pNext = NULL;
bind_image_plane0_info.planeAspect = VK_IMAGE_ASPECT_PLANE_0_BIT;
VkBindImageMemoryInfo& bind_image_memory_plane0_info = bind_image_memory_infos[0];
bind_image_memory_plane0_info.sType = VK_STRUCTURE_TYPE_BIND_IMAGE_MEMORY_INFO;
bind_image_memory_plane0_info.pNext = &bind_image_plane0_info;
bind_image_memory_plane0_info.image = image;
bind_image_memory_plane0_info.memory = image_memory;
bind_image_memory_plane0_info.memoryOffset = memory_offset_plane0;
//Plane 1
VkBindImagePlaneMemoryInfo bind_image_plane1_info = {};
bind_image_plane1_info.sType = VK_STRUCTURE_TYPE_BIND_IMAGE_PLANE_MEMORY_INFO;
bind_image_plane1_info.pNext = NULL;
bind_image_plane1_info.planeAspect = VK_IMAGE_ASPECT_PLANE_1_BIT;
VkBindImageMemoryInfo& bind_image_memory_plane1_info = bind_image_memory_infos[1];
bind_image_memory_plane1_info.sType = VK_STRUCTURE_TYPE_BIND_IMAGE_MEMORY_INFO;
bind_image_memory_plane1_info.pNext = &bind_image_plane1_info;
bind_image_memory_plane1_info.image = image;
bind_image_memory_plane1_info.memory = image_memory;
bind_image_memory_plane1_info.memoryOffset = memory_offset_plane1;
vkBindImageMemory2(logical_device, bind_image_memory_infos.size(), bind_image_memory_infos.data());
context.transition_vk_image_layout(image, format, VK_IMAGE_ASPECT_COLOR_BIT, VK_IMAGE_LAYOUT_PREINITIALIZED, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL);
//Copy staging buffer to device local buffer
VkCommandBuffer tmp_cmd_buffer = begin_tmp_vk_cmd_buffer();
std::vector<VkBufferImageCopy> plane_regions(2);
plane_regions[0].bufferOffset = 0;
plane_regions[0].bufferRowLength = 0;
plane_regions[0].bufferImageHeight = 0;
plane_regions[0].imageSubresource.aspectMask = VK_IMAGE_ASPECT_PLANE_0_BIT;
plane_regions[0].imageSubresource.mipLevel = 0;
plane_regions[0].imageSubresource.baseArrayLayer = 0;
plane_regions[0].imageSubresource.layerCount = 1;
plane_regions[0].imageOffset = { 0, 0, 0 };
plane_regions[0].imageExtent = { width, height, 1 };
plane_regions[1].bufferOffset = buffer_offset_plane1;
plane_regions[1].bufferRowLength = 0;
plane_regions[1].bufferImageHeight = 0;
plane_regions[1].imageSubresource.aspectMask = VK_IMAGE_ASPECT_PLANE_1_BIT;
plane_regions[1].imageSubresource.mipLevel = 0;
plane_regions[1].imageSubresource.baseArrayLayer = 0;
plane_regions[1].imageSubresource.layerCount = 1;
plane_regions[1].imageOffset = { 0, 0, 0 };
plane_regions[1].imageExtent = { width / 2, height / 2, 1 };
vkCmdCopyBufferToImage(tmp_cmd_buffer, stage_buffer, image, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, plane_regions.size(), plane_regions.data());
end_tmp_vk_cmd_buffer(tmp_cmd_buffer); //Submit and waits
vkFreeMemory(logical_device, stage_buffer_memory, NULL);
vkDestroyBuffer(logical_device, stage_buffer, NULL);
transition_vk_image_layout(image, format, VK_IMAGE_ASPECT_COLOR_BIT, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL);
VkImageViewCreateInfo image_view_info = {};
image_view_info.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
image_view_info.pNext = &ycbcr_info;
image_view_info.flags = 0;
image_view_info.image = image;
image_view_info.viewType = VK_IMAGE_VIEW_TYPE_2D;
image_view_info.format = format;
image_view_info.components.r = VK_COMPONENT_SWIZZLE_IDENTITY;
image_view_info.components.b = VK_COMPONENT_SWIZZLE_IDENTITY;
image_view_info.components.g = VK_COMPONENT_SWIZZLE_IDENTITY;
image_view_info.components.a = VK_COMPONENT_SWIZZLE_IDENTITY;
image_view_info.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
image_view_info.subresourceRange.baseMipLevel = 0;
image_view_info.subresourceRange.levelCount = 1;
image_view_info.subresourceRange.baseArrayLayer = 0;
image_view_info.subresourceRange.layerCount = 1;
VkResult res = vkCreateImageView(logical_device, &image_view_info, NULL, &.image_view);
CHECK_VK_RESULT(res, "Failed to create image view");
ILOG("Successfully created image, allocated image memory and created image view");
我收到一个验证错误：vkCmdCopyBufferToImage() parameter, VkImageAspect pRegions->imageSubresource.aspectMask, is an unrecognized enumerator，但是从检查验证代码来看，似乎有点过时了，这不应该成为问题。
其余代码仅设置常规描述符布局/池并进行相应的分配和更新（我已经使用常规RGB纹理进行了验证）。
片段着色器如下：
vec2 uv = vec2(gl_FragCoord.x / 1024.0, 1.0 - (gl_FragCoord.y / 1024.0));
out_color = vec4(texture(ycbcr_image, uv).rgb, 1.0f);
运行程序时，我只会得到红色的分量（该图像本质上是灰度图像）。从一点测试来看，似乎VkSamplerYcbcrconversion设置从VkSamplerCreateInfo.pNext和VkImageViewCreateInfo.pNext中删除都没有任何改变。
我也曾在这里看过Khronos YCbCr tests，但我找不到任何真正的错误。任何帮助将非常感激！ ：）
答案 0 :(得分：2)
解决方案：根据规格，以秒为单位。 12.1，必须在管道创建时通过在VkDescriptorSetLayoutBinding中将图像采样器与不可变采样器结合使用来固定转换。
通过在设置描述符集布局绑定时将 ycbcr_sampler 添加到 pImmutableSamplers ，它现在可以工作：
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