通过文档和示例的方式很少,但经过一些挖掘后,似乎有些人通过将帧读入纹理并将该纹理的内容复制到记忆可读纹理(我甚至不是确定我在这里使用正确的条款).尝试我发现的虽然给了我错误,我可能做了一堆错误.
ComPtr<ID3D11Texture2D> spTextureDst;
MEDIA::ThrowIfFailed(
m_spDX11SwapChain->GetBuffer(0,IID_PPV_ARGS(&spTextureDst))
);
auto rcNormalized = MFVideoNormalizedRect();
rcNormalized.left = 0;
rcNormalized.right = 1;
rcNormalized.top = 0;
rcNormalized.bottom = 1;
MEDIA::ThrowIfFailed(
m_spMediaEngine->TransferVideoFrame(m_spRenderTexture.Get(),&rcNormalized,&m_rcTarget,&m_bkgColor)
);
//copy the render target texture to the readable texture.
m_spDX11DeviceContext->CopySubresourceRegion(m_spCopyTexture.Get(),m_spRenderTexture.Get(),NULL);
m_spDX11DeviceContext->Flush();
//Map the readable texture;
D3D11_MAPPED_SUBRESOURCE mapped = {0};
m_spDX11DeviceContext->Map(m_spCopyTexture.Get(),D3D11_MAP_READ,&mapped);
void* buffer = ::CoTaskMemAlloc(600 * 400 * 3);
memcpy(buffer,mapped.pData,600 * 400 * 3);
//unmap so we can copy during next update.
m_spDX11DeviceContext->Unmap(m_spCopyTexture.Get(),0);
// and the present it to the screen
MEDIA::ThrowIfFailed(
m_spDX11SwapChain->Present(1,0)
);
}
我得到的错误是：
First-chance exception at 0x76814B32 in App1.exe: Microsoft C++ exception: Platform::InvalidArgumentException ^ at memory location 0x07AFF60C. HRESULT:0x80070057
我不太确定如何进一步追求它,因为就像我说的那样,关于它的文档很少.
Here’s the modified sample我正在工作.此问题特定于WinRT(Windows 8应用程序).
解决方法
部分成功,但也许足以回答你的问题.请继续阅读.
在我的系统上,调试异常表明OnTimer()函数在尝试调用TransferVideoFrame()时失败.它给出的错误是InvalidArgumentException.
所以,一点谷歌搜索引发了我的第一次发现 – 显然是a bug in NVIDIA drivers – 这意味着视频播放似乎失败了11和10个功能级别.
所以我的第一个更改是在函数CreateDX11Device()中,如下所示：
static const D3D_FEATURE_LEVEL levels[] = {
/*
D3D_FEATURE_LEVEL_11_1,D3D_FEATURE_LEVEL_11_0,D3D_FEATURE_LEVEL_10_1,D3D_FEATURE_LEVEL_10_0,*/
D3D_FEATURE_LEVEL_9_3,D3D_FEATURE_LEVEL_9_2,D3D_FEATURE_LEVEL_9_1
};
现在TransferVideoFrame()仍然失败,但是给出了E_FAIL(作为HRESULT)而不是无效的参数.
更多谷歌搜索导致我的second discovery –
这是一个示例,显示使用TransferVideoFrame()而不使用CreateTexture2D()来预先创建纹理.我看到你已经在OnTimer()中有一些代码与此类似,但没有使用,所以我猜你找到了相同的链接.
ComPtr <ID3D11Texture2D> spTextureDst; m_spDX11SwapChain->GetBuffer (0,IID_PPV_ARGS (&spTextureDst)); m_spMediaEngine->TransferVideoFrame (spTextureDst.Get (),nullptr,&m_bkgColor);
执行此操作后,我看到TransferVideoFrame()成功(好！)但在复制的纹理上调用Map() – m_spCopyTexture – 失败,因为该纹理不是使用cpu读取访问创建的.
所以,我只是使用你的读/写m_spRenderTexture作为副本的目标,因为它具有正确的标志,并且由于之前的更改,我不再使用它.
//copy the render target texture to the readable texture.
m_spDX11DeviceContext->CopySubresourceRegion(m_spRenderTexture.Get(),spTextureDst.Get(),NULL);
m_spDX11DeviceContext->Flush();
//Map the readable texture;
D3D11_MAPPED_SUBRESOURCE mapped = {0};
HRESULT hr = m_spDX11DeviceContext->Map(m_spRenderTexture.Get(),&mapped);
void* buffer = ::CoTaskMemAlloc(176 * 144 * 3);
memcpy(buffer,176 * 144 * 3);
//unmap so we can copy during next update.
m_spDX11DeviceContext->Unmap(m_spRenderTexture.Get(),0);
现在,在我的系统上,OnTimer()函数不会失败.视频帧被渲染到纹理,像素数据被成功复制到内存缓冲区.
在考虑是否还有其他问题之前,也许现在是时候看看你能否取得与我迄今为止相同的进步.如果您使用更多信息对此答案发表评论,我将编辑答案,以便在可能的情况下添加更多帮助.
编辑
在FramePlayer :: CreateBackBuffers()中对纹理描述所做的更改
//make first texture cpu readable D3D11_TEXTURE2D_DESC texDesc = {0}; texDesc.Width = 176; texDesc.Height = 144; texDesc.MipLevels = 1; texDesc.ArraySize = 1; texDesc.Format = DXGI_FORMAT_B8G8R8A8_UNORM; texDesc.SampleDesc.Count = 1; texDesc.SampleDesc.Quality = 0; texDesc.Usage = D3D11_USAGE_STAGING; texDesc.BindFlags = 0; texDesc.cpuAccessFlags = D3D11_cpu_ACCESS_READ | D3D11_cpu_ACCESS_WRITE; texDesc.MiscFlags = 0; MEDIA::ThrowIfFailed(m_spDX11Device->CreateTexture2D(&texDesc,NULL,&m_spRenderTexture));
还要注意,有时需要清除内存泄漏(我确定你知道) – 以下行中分配的内存永远不会被释放：
void* buffer = ::CoTaskMemAlloc(176 * 144 * 3); // sizes changed for my test
成功
我现在已经成功保存了一个单独的框架,但现在没有使用复制纹理.
首先,我下载了最新版本的the DirectXTex Library,它提供了DX11纹理辅助函数,例如从纹理中提取图像并保存到文件. The instructions用于将DirectXTex库添加到您的解决方案作为现有项目需要仔细遵循,注意Windows 8商店应用程序所需的更改.
一旦,包含,引用和构建上面的库,将以下#include添加到FramePlayer.cpp
#include "..\DirectXTex\DirectXTex.h" // nb - use the relative path you copied to #include <wincodec.h>
最后,FramePlayer :: OnTimer()中的代码的中心部分需要类似于以下内容.您将看到我每次都保存到相同的文件名,因此需要修改以添加例如名称的帧号
// new frame available at the media engine so get it ComPtr<ID3D11Texture2D> spTextureDst; MEDIA::ThrowIfFailed(m_spDX11SwapChain->GetBuffer(0,IID_PPV_ARGS(&spTextureDst))); auto rcNormalized = MFVideoNormalizedRect(); rcNormalized.left = 0; rcNormalized.right = 1; rcNormalized.top = 0; rcNormalized.bottom = 1; MEDIA::ThrowIfFailed(m_spMediaEngine->TransferVideoFrame(spTextureDst.Get(),&m_bkgColor)); // capture an image from the DX11 texture DirectX::ScratchImage pImage; HRESULT hr = DirectX::CaptureTexture(m_spDX11Device.Get(),m_spDX11DeviceContext.Get(),pImage); if (SUCCEEDED(hr)) { // get the image object from the wrapper const DirectX::Image *pRealImage = pImage.GetImage(0,0); // set some place to save the image frame StorageFolder ^dataFolder = ApplicationData::Current->LocalFolder; Platform::String ^szPath = dataFolder->Path + "\\frame.png"; // save the image to file hr = DirectX::SaveToWICFile(*pRealImage,DirectX::WIC_FLAGS_NONE,GUID_ContainerFormatPng,szPath->Data()); } // and the present it to the screen MEDIA::ThrowIfFailed(m_spDX11SwapChain->Present(1,0));
我现在没有时间进一步采取这一点,但我对目前为止取得的成就感到非常满意:-))
您能否重新审视并在评论中更新结果？
