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• NV12 textures not working in DirectX 11.1

  28 mars 2017, par André Vitor

  I’m trying to render NV12 textures from frames decoded with ffmpeg 2.8.11 using DirectX 11.1 but when I do render them the texture is broken and the color is always off.

  Result is : http://imgur.com/a/YIVQk

  Code below is how I get the frame decoded by ffmpeg that is in YUV420P format and then I convert(not sure) to NV12 format by interleaving the U and V planes.

  static uint8_t *pixelsPtr_ = nullptr;
  
  
  
  UINT rowPitch = ((width + 1) >> 1) * 2;
  
  UINT imageSize = (rowPitch * height) + ((rowPitch * height + 1) >> 1);
  
  
  
  if (!pixelsPtr_)
  
  {
  
      pixelsPtr_ = new uint8_t[imageSize];
  
  }
  
  
  
  int j, position = 0;
  
  
  
  uint32_t pitchY = avFrame.linesize[0];
  
  uint32_t pitchU = avFrame.linesize[1];
  
  uint32_t pitchV = avFrame.linesize[2];
  
  
  
  uint8_t *avY = avFrame.data[0];
  
  uint8_t *avU = avFrame.data[1];
  
  uint8_t *avV = avFrame.data[2];
  
  
  
  ::SecureZeroMemory(pixelsPtr_, imageSize);
  
  
  
  for (j = 0; j < height; j++)
  
  {               
  
      ::CopyMemory(pixelsPtr_ + position, avY, (width));
  
      position += (width);
  
      avY += pitchY;
  
  }
  
  
  
  for (j = 0; j < height >> 1; j++)
  
  {
  
      ::CopyMemory(pixelsPtr_ + position, avU, (width >> 1));
  
      position += (width >> 1);
  
      avU += pitchU;
  
  
  
      ::CopyMemory(pixelsPtr_ + position, avV, (width >> 1));
  
      position += (width >> 1);
  
      avV += pitchV;
  
  }

  This is how I’m creating the Texture2D with the data I just got.

  // Create texture
  
  D3D11_TEXTURE2D_DESC desc;
  
  desc.Width = width;
  
  desc.Height = height;
  
  desc.MipLevels = 1;
  
  desc.ArraySize = 1;
  
  desc.Format = DXGI_FORMAT_NV12;
  
  desc.SampleDesc.Count = 1;
  
  desc.SampleDesc.Quality = 0;
  
  desc.Usage = D3D11_USAGE_DEFAULT;
  
  desc.BindFlags = D3D11_BIND_SHADER_RESOURCE;
  
  desc.CPUAccessFlags = 0;
  
  desc.MiscFlags = 0;
  
  
  
  D3D11_SUBRESOURCE_DATA initData;
  
  initData.pSysMem = pixelsPtr_;
  
  initData.SysMemPitch = rowPitch;
  
  
  
  ID3D11Texture2D* tex = nullptr;
  
  hr = d3dDevice->CreateTexture2D(&desc, &initData, &tex);
  
  if (SUCCEEDED(hr) && tex != 0)
  
  {
  
      D3D11_SHADER_RESOURCE_VIEW_DESC SRVDesc;
  
      memset(&SRVDesc, 0, sizeof(SRVDesc));
  
      SRVDesc.Format = DXGI_FORMAT_R8_UNORM;
  
      SRVDesc.ViewDimension = D3D11_SRV_DIMENSION_TEXTURE2D;
  
      SRVDesc.Texture2D.MipLevels = 1;
  
  
  
      hr = d3dDevice->CreateShaderResourceView(tex, &SRVDesc, &textureViewYUV[0]);
  
      if (FAILED(hr))
  
      {
  
          tex->Release();
  
          return hr;
  
      }
  
  
  
      SRVDesc.Format = DXGI_FORMAT_R8G8_UNORM;
  
  
  
      hr = d3dDevice->CreateShaderResourceView(tex, &SRVDesc, &textureViewYUV[1]);
  
      if (FAILED(hr))
  
      {
  
          tex->Release();
  
          return hr;
  
      }
  
  
  
      tex->Release();
  
  }

  Then I pass both Shader Resource View to Pixel Shader

  graphics->Context()->PSSetShaderResources(0, 2, textureViewYUV);

  This is the pixel shader :

  struct PixelShaderInput
  
  {
  
      float4 pos         : SV_POSITION;
  
      float4 Color       : COLOR;
  
      float2 texCoord    : TEXCOORD;
  
  };
  
  
  
  static const float3x3 YUVtoRGBCoeffMatrix =
  
  {
  
      1.164383f,  1.164383f, 1.164383f,
  
      0.000000f, -0.391762f, 2.017232f,
  
      1.596027f, -0.812968f, 0.000000f
  
  };
  
  
  
  Texture2D<float>  luminanceChannel;
  
  Texture2D<float2> chrominanceChannel;
  
  
  
  SamplerState linearfilter
  
  {
  
      Filter = MIN_MAG_MIP_LINEAR;
  
  };
  
  
  
  float3 ConvertYUVtoRGB(float3 yuv)
  
  {
  
      // Derived from https://msdn.microsoft.com/en-us/library/windows/desktop/dd206750(v=vs.85).aspx
  
      // Section: Converting 8-bit YUV to RGB888
  
  
  
      // These values are calculated from (16 / 255) and (128 / 255)
  
      yuv -= float3(0.062745f, 0.501960f, 0.501960f);
  
      yuv = mul(yuv, YUVtoRGBCoeffMatrix);
  
  
  
      return saturate(yuv);
  
  }
  
  
  
  float4 main(PixelShaderInput input) : SV_TARGET
  
  {
  
      float y = luminanceChannel.Sample(linearfilter, input.texCoord);
  
      float2 uv = chrominanceChannel.Sample(linearfilter, input.texCoord);
  
  
  
      float3 YUV = float3(y, uv.x, uv.y);
  
      float4 YUV4 = float4(YUV.x, YUV.y, YUV.z, 1);
  
  
  
      float3 RGB = ConvertYUVtoRGB(YUV);
  
      float4 RGB4 = float4(RGB.x, RGB.y, RGB.z, 1);
  
  
  
      return RGB4;
  
  }
  
  </float2></float>

  Can someone help me ? What I’m doing wrong ?

  EDIT #1

  int skipLineArea = 0;
  
  int uvCount = (height >> 1) * (width >> 1);
  
  
  
  for (j = 0, k = 0; j < uvCount; j++, k++)
  
  {
  
      if (skipLineArea == (width >> 1))
  
      {
  
          k += pitchU - (width >> 1);
  
          skipLineArea = 0;
  
      }
  
  
  
      pixelsPtr_[position++] = avU[k];
  
      pixelsPtr_[position++] = avV[k];
  
      skipLineArea++;
  
  }

  EDIT #2

  Updating the texture instead of creating new ones

  D3D11_MAPPED_SUBRESOURCE mappedResource;
  
  d3dContext->Map(tex, 0, D3D11_MAP_WRITE_DISCARD, 0, &mappedResource);
  
  
  
  uint8_t* mappedData = reinterpret_cast(mappedResource.pData);
  
  
  
  for (UINT i = 0; i < height * 1.5; ++i)
  
  {
  
      memcpy(mappedData, frameData, rowPitch);
  
      mappedData += mappedResource.RowPitch;
  
      frameData += rowPitch;
  
  }
  
  
  
  d3dContext->Unmap(tex, 0);

• h264_mp4toannexb : Improve extradata overread checks

  14 décembre 2019, par Andreas Rheinhardt

  h264_mp4toannexb : Improve extradata overread checks
  Currently during parsing the extradata, h264_mp4toannexb checks for
  
  overreads by adding the size of the current unit to the current position
  
  pointer and comparing this to the end position of the extradata. But
  
  pointer comparisons and pointer arithmetic are only defined if it does not
  
  exceed the object it is used on (one past the last element of an array
  
  is allowed, too). In practice, this might lead to overflows. Therefore
  
  the check has been changed to use bytestream2_get_bytes_left() which
  
  means that the pointers get subtracted and the result gets compared to
  
  the available size.
  Furthermore, the error code has been fixed.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/h264_mp4toannexb_bsf.c

• HEVC : Fetching the input width and height from input bin stream

  3 septembre 2014, par Zax

  I have created an elementary bin stream using HM-12.0 reference code. So the out put is an HEVC encoded bin stream (say input.bin).

  I have a task which involves reading the header of this elementary stream. That is i need to fetch information such a the stream width, height etc. from the input.bin file.

  After seeing a lots of streams, i can conclude that all these bin streams starts from the sequence :

  00 00 00 01

  So whenever i see this sequence in any bin stream, i can say that this stream has to be decoded by HEVC decoder.

  Further if i want to fetch the width, height, fps etc. from the input.bin (like ff_raw_video_read_header function in ffmpeg), that are the steps need to be performed to fetch this information ?

  I have gone through the parsing section of the HEVC draft, but its very complicated for my level in video domain. Can anyone suggest a simple way to fetch the required information from the encoded bin file ?

  Any suggestions will be really helpful to me. Thanks in advance.