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D3D三层Texture纹理经像素着色器实现渲染YUV420P

    简单记录一下这两天用Texture实现渲染YUV420P的一些要点。

    在视频播放的过程中,有的时候解码出来的数据是YUV420P的。表面(surface)通过设置参数是可以渲染YUV420P的,但Texture纹理似乎不支持直接渲染YUV420P。表面(surface)用法似乎比较单一,通常用来显示数据,用Texture的话就可以用上D3D的许多其他功能,做出一些效果。当然,这看个人需求,通常而言显示视频数据用表面就够了。

1.利用像素着色器把YUV420P数据转为RGB32

   视频播放过程中帧与帧之间是有固定时间间隔的。若解码解出来的是YUV420P的数据,要用Texture渲染的话,就需要把数据转为RGB32的(应该是要转成RGB32的,没做过详细调查,看到的例子中纹理所用的数据都是RGB32的),如果这个过程交给CPU去做的话,会提高CPU的占用率,用GPU来做这项工作则就释放了CPU的一部分压力。

    本文考虑的方式是用三层纹理分别存放YUV420P的Y、U、V分量(这个词不知道用对没有),然后像素着色器把三个分量的数据计算成RGB32的数据然后显示。这是本文的核心内容。

像素着色器的HLSL代码如下:

sampler YTex;sampler UTex;sampler VTex;struct PS_INPUT{    float2 y    : TEXCOORD0;    float2 u    : TEXCOORD1;    float2 v    : TEXCOORD2;};float4 Main(PS_INPUT input):COLOR0{          float y = tex2D(YTex,input.y).r;    float u = tex2D(UTex, input.u.xy / 2).r  - 0.5f;    float v = tex2D(VTex,input.v.xy / 2).r  - 0.5f;                                float r = y + 1.14f * v;    float g = y - 0.394f * u - 0.581f * v;    float b = y + 2.03f * u;                    return float4(r,g,b, 1);}

     HLSL代码可以直接写在txt文件中,sampler可视作标识纹理层和采样级的对象,Direct3D将把每一个sampler对象唯一地与某一纹理层关联起来。具体的HLSL语法请自行查资料,我也是粗略知道是怎么回事,就不误人子弟了。在代码中通过调用D3DXCompileShaderFromFile函数可以从文件编译像素着色器。但实际上,我个人不是很喜欢这种把代码放在一个单独文件里面的做法,这种代码应该尽可能的编进exe里面。但是我还只是初步了解D3D,不知道怎么把它编进exe里面,如果有人知道,还望指教。

ID3DXBuffer* shader      = 0;ID3DXBuffer* errorBuffer = 0;hr = D3DXCompileShaderFromFile(    "ps_multitex.txt",    0,    0,    "Main", // entry point function name    "ps_2_0",    D3DXSHADER_DEBUG,     &shader,    &errorBuffer,    &MultiTexCT);// output any error messagesif( errorBuffer ){    ::MessageBox(0, (char*)errorBuffer->GetBufferPointer(), 0, 0);    d3d::Release<ID3DXBuffer*>(errorBuffer);}if(FAILED(hr)){    ::MessageBox(0, "D3DXCompileShaderFromFile() - FAILED", 0, 0);    return false;}//// Create Pixel Shader//hr = Device->CreatePixelShader(    (DWORD*)shader->GetBufferPointer(),    &MultiTexPS);if(FAILED(hr)){    ::MessageBox(0, "CreateVertexShader - FAILED", 0, 0);    return false;}d3d::Release<ID3DXBuffer*>(shader);

以上代码中,D3DXCompileShaderFromFile函数从文件ps_multitex.txt编译HLSL代码;参数Main是HLSL代码的入口函数,如上一点代码中所见。这个入口函数可以是自定义的其他的,但要注意保持一致;ps_2_0表示像素着色器的版本。CreatePixelShader函数创建像素着色器。

2.sampler与纹理关联

    创建纹理层。本文实现YUV420P渲染的方法采用了三层纹理,每层纹理分别存放Y、U、V数据。

Device->CreateTexture ( Width, Height, 1, D3DUSAGE_DYNAMIC, D3DFMT_L8, D3DPOOL_DEFAULT, &YTex, NULL ) ;Device->CreateTexture ( Width / 2, Height / 2, 1, D3DUSAGE_DYNAMIC, D3DFMT_L8, D3DPOOL_DEFAULT, &UTex, NULL ) ;Device->CreateTexture ( Width / 2, Height / 2, 1, D3DUSAGE_DYNAMIC, D3DFMT_L8, D3DPOOL_DEFAULT, &VTex, NULL ) ;

    sampler与纹理的关联

// // Get Handles//YTexHandle      = MultiTexCT->GetConstantByName(0, "YTex");UTexHandle        = MultiTexCT->GetConstantByName(0, "UTex");VTexHandle        = MultiTexCT->GetConstantByName(0, "VTex");//// Set constant descriptions://UINT count;MultiTexCT->GetConstantDesc(YTexHandle,      &YTexDesc, &count);MultiTexCT->GetConstantDesc(UTexHandle, &UTexDesc, &count);MultiTexCT->GetConstantDesc(VTexHandle,    &VTexDesc, &count);MultiTexCT->SetDefaults(Device);

    设置纹理/sampler的状态,这一部分我是在渲染的时候做的,也可以直接写在HLSL代码中。在后面渲染部分还会见到这些代码,其实是同一段代码,我只是为了表述纹理与sampler关联的一个整体过程,把它预先从渲染部分截了出来,希望不会造成误解。

// Y texDevice->SetTexture(     YTexDesc.RegisterIndex, YTex);Device->SetSamplerState(YTexDesc.RegisterIndex, D3DSAMP_MAGFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(YTexDesc.RegisterIndex, D3DSAMP_MINFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(YTexDesc.RegisterIndex, D3DSAMP_MIPFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(YTexDesc.RegisterIndex, D3DSAMP_ADDRESSU, D3DTADDRESS_BORDER);Device->SetSamplerState(YTexDesc.RegisterIndex, D3DSAMP_ADDRESSV, D3DTADDRESS_BORDER);// U texDevice->SetTexture(     UTexDesc.RegisterIndex, UTex);Device->SetSamplerState(UTexDesc.RegisterIndex, D3DSAMP_MAGFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(UTexDesc.RegisterIndex, D3DSAMP_MINFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(UTexDesc.RegisterIndex, D3DSAMP_MIPFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(UTexDesc.RegisterIndex, D3DSAMP_ADDRESSU, D3DTADDRESS_BORDER);Device->SetSamplerState(UTexDesc.RegisterIndex, D3DSAMP_ADDRESSV, D3DTADDRESS_BORDER);// string texDevice->SetTexture(     VTexDesc.RegisterIndex, VTex);Device->SetSamplerState(VTexDesc.RegisterIndex, D3DSAMP_MAGFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(VTexDesc.RegisterIndex, D3DSAMP_MINFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(VTexDesc.RegisterIndex, D3DSAMP_MIPFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(VTexDesc.RegisterIndex, D3DSAMP_ADDRESSU, D3DTADDRESS_BORDER);Device->SetSamplerState(VTexDesc.RegisterIndex, D3DSAMP_ADDRESSV, D3DTADDRESS_BORDER);

3.渲染YUV420P

    获得YUV420P数据。本文直接读取的YUV420P数据。

打开文件代码:

if((infile=fopen("test_yuv420p_320x180.yuv", "rb"))==NULL){    printf("cannot open this file\n");    return false;}

读取数据并将数据copy到纹理中:

if (fread(buf, 1, Width*Height*3/2, infile) != Width*Height*3/2){        // Loop        fseek(infile, 0, SEEK_SET);        fread(buf, 1, Width*Height*3/2, infile);    }//// Render//Device->Clear(0, 0, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0xffffffff, 1.0f, 0);plane[0] = buf;plane[1] = plane[0] + Width*Height;plane[2] = plane[1] + Width*Height/4;D3DLOCKED_RECT d3d_rect;byte *pSrc =http://www.mamicode.com/ buf;//Locks a rectangle on a texture resource.//And then we can manipulate pixel data in it.LRESULT lRet = YTex->LockRect(0, &d3d_rect, 0, 0);if (FAILED(lRet)){    return false;}// Copy pixel data to texturebyte *pDest = (byte *)d3d_rect.pBits;int stride = d3d_rect.Pitch; for(int i = 0;i < Height;i ++){    memcpy(pDest + i * stride,plane[0] + i * Width, Width);}YTex->UnlockRect(0);D3DLOCKED_RECT d3d_rect1;lRet = UTex->LockRect(0, &d3d_rect1, 0, 0);if (FAILED(lRet)){    return false;}// Copy pixel data to texturebyte *pDest1 = (byte *)d3d_rect1.pBits;int stride1 = d3d_rect1.Pitch; for(int i = 0;i < Height/2;i ++){    memcpy(pDest1 + i * stride1 / 2,plane[1] + i * Width / 2, Width / 2);}UTex->UnlockRect(0);D3DLOCKED_RECT d3d_rect2;lRet =  VTex->LockRect(0, &d3d_rect2, 0, 0);if (FAILED(lRet)){    return false;}// Copy pixel data to texturebyte *pDest2 = (byte *)d3d_rect2.pBits;int stride2 = d3d_rect2.Pitch; for(int i = 0;i < Height/2;i ++){    memcpy(pDest2 + i * stride2 / 2,plane[2] + i * Width / 2, Width / 2);}VTex->UnlockRect(0);

渲染:

Device->BeginScene();Device->SetPixelShader(MultiTexPS);Device->SetFVF(MultiTexVertex::FVF);Device->SetStreamSource(0, QuadVB, 0, sizeof(MultiTexVertex));// Y texDevice->SetTexture(     YTexDesc.RegisterIndex, YTex);Device->SetSamplerState(YTexDesc.RegisterIndex, D3DSAMP_MAGFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(YTexDesc.RegisterIndex, D3DSAMP_MINFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(YTexDesc.RegisterIndex, D3DSAMP_MIPFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(YTexDesc.RegisterIndex, D3DSAMP_ADDRESSU, D3DTADDRESS_BORDER);Device->SetSamplerState(YTexDesc.RegisterIndex, D3DSAMP_ADDRESSV, D3DTADDRESS_BORDER);// U texDevice->SetTexture(     UTexDesc.RegisterIndex, UTex);Device->SetSamplerState(UTexDesc.RegisterIndex, D3DSAMP_MAGFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(UTexDesc.RegisterIndex, D3DSAMP_MINFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(UTexDesc.RegisterIndex, D3DSAMP_MIPFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(UTexDesc.RegisterIndex, D3DSAMP_ADDRESSU, D3DTADDRESS_BORDER);Device->SetSamplerState(UTexDesc.RegisterIndex, D3DSAMP_ADDRESSV, D3DTADDRESS_BORDER);// string texDevice->SetTexture(     VTexDesc.RegisterIndex, VTex);Device->SetSamplerState(VTexDesc.RegisterIndex, D3DSAMP_MAGFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(VTexDesc.RegisterIndex, D3DSAMP_MINFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(VTexDesc.RegisterIndex, D3DSAMP_MIPFILTER, D3DTEXF_LINEAR);Device->SetSamplerState(VTexDesc.RegisterIndex, D3DSAMP_ADDRESSU, D3DTADDRESS_BORDER);Device->SetSamplerState(VTexDesc.RegisterIndex, D3DSAMP_ADDRESSV, D3DTADDRESS_BORDER);Device->DrawPrimitive(D3DPT_TRIANGLELIST, 0, 2);Device->EndScene();Device->Present(0, 0, 0, 0);

 

D3D Texture纹理渲染YUV420P的主要就是以上一些内容。完整工程代码:http://download.csdn.net/download/qq_33892166/9702415

本文的HLSL代码写出来的像素着色器画面有些偏黄,知道如何优化的朋友还请指教。

D3D三层Texture纹理经像素着色器实现渲染YUV420P