directX 11 scale texture2D - c++

Question

I would like to scale a texture I created from AcquireNextFrame.
Here is my code :
if (gRealTexture == nullptr) {
D3D11_TEXTURE2D_DESC description;
texture2D->GetDesc(&description);
description.BindFlags = 0;
description.CPUAccessFlags = D3D11_CPU_ACCESS_READ | D3D11_CPU_ACCESS_WRITE;
description.Usage = D3D11_USAGE_STAGING;
description.MiscFlags = 0;
hr = gDevice->CreateTexture2D(&description, NULL, &gRealTexture);
if (FAILED(hr)) {
if (gRealTexture) {
gRealTexture->Release();
gRealTexture = nullptr;
}
return NULL;
}
}
gImmediateContext->CopyResource(gRealTexture, texture2D);
D3D11_MAPPED_SUBRESOURCE mapped;
hr = gImmediateContext->Map(gRealTexture, 0, D3D11_MAP_READ_WRITE, 0, &mapped);
if (FAILED(hr)) {
gRealTexture->Release();
gRealTexture = NULL;
return NULL;
}
unsigned char *source = static_cast<unsigned char *>(mapped.pData); //Here I get the pixel buffer data
Problem is that it is in Full HD Resolution (1920x1080). I would like to decrease the resolution (1280x720 for example) because I need to send source over network. And I don't really need a Full HD image.
Is it possible to do it with DirectX easily before I get the pixel buffer ?
Thanks

Answer 1

Create a smaller resolution texture, render the texture2d to the smaller texture using a fullscreen quad (but shrinking to the new size). Make sure bilinear filtering is on.
Then copy and map the smaller texture. CopyResource needs the same dimensions.
Some resources:
DX11 Helper Library
Render To Texture
DX11 Post Processing blur
The blur setup is the same as what I'm talking about, only instead of using a blur shader you use a simple texture shader.