如何在DirectX 10中将后备缓冲保存到文件？

Question

我希望使用DirectX 10逐帧渲染视频。之后，这些帧将由其他工具（如mencoder或ffmpeg）进行处理。

在DX9中使用D3DXSaveSurfaceToFile没有任何问题。

现在，在DX10中，我找到了D3DX10SaveTextureToFile，但是在尝试保存后备缓冲区时没有成功。

我使用以下代码：

ID3D10Resource *backbufferRes;
_defaultRenderTargetView->GetResource(&backbufferRes);

D3D10_TEXTURE2D_DESC texDesc;
texDesc.ArraySize = 1;
texDesc.BindFlags = 0;
texDesc.CPUAccessFlags = D3D10_CPU_ACCESS_READ;
texDesc.Format = backbufferSurfDesc.Format;
texDesc.Height = backbufferSurfDesc.Height;
texDesc.Width = backbufferSurfDesc.Width;
texDesc.MipLevels = 1;
texDesc.MiscFlags = 0;
texDesc.SampleDesc = backbufferSurfDesc.SampleDesc;
texDesc.Usage = D3D10_USAGE_STAGING;

ID3D10Texture2D *texture;
HRESULT hr;
V( _device->CreateTexture2D(&texDesc, 0, &texture) );
_device->CopyResource(texture, backbufferRes);

V( D3DX10SaveTextureToFile(texture, D3DX10_IFF_DDS, filename) );
texture->Release();

这会创建一个.dds图片，但我不知道任何DDS查看器/编辑器可以打开它。

我的代码有什么问题？

- shinjin

Answer 1

所有的功劳归功于gamedev.net的sepul。

现在，问题是：

• texDesc.CPUAccessFlags 应该为 0
• texDesc.Format 应该为 DXGI_FORMAT_R8G8B8A8_UNORM
• texDesc.SampleDesc.Count 应该为 1
• texDesc.SampleDesc.Quality 应该为 0
• texDesc.Usage 应该为 D3D10_USAGE_DEFAULT

这样一来，D3DX10SaveTextureToFile 就可以保存为 BMP 或者 PNG。

完整代码如下：

HRESULT hr;
ID3D10Resource *backbufferRes;
_defaultRenderTargetView->GetResource(&backbufferRes);

D3D10_TEXTURE2D_DESC texDesc;
texDesc.ArraySize = 1;
texDesc.BindFlags = 0;
texDesc.CPUAccessFlags = 0;
texDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
texDesc.Width = 640;  // must be same as backbuffer
texDesc.Height = 480; // must be same as backbuffer
texDesc.MipLevels = 1;
texDesc.MiscFlags = 0;
texDesc.SampleDesc.Count = 1;
texDesc.SampleDesc.Quality = 0;
texDesc.Usage = D3D10_USAGE_DEFAULT;

ID3D10Texture2D *texture;
V( _device->CreateTexture2D(&texDesc, 0, &texture) );
_device->CopyResource(texture, backbufferRes);

V( D3DX10SaveTextureToFile(texture, D3DX10_IFF_PNG, L"test.png") );
texture->Release();
backbufferRes->Release();

- shinjin